WorldWideScience

Sample records for induced early superstring

  1. Superstrings

    International Nuclear Information System (INIS)

    Davies, P.C.W.; Brown, Julian

    1988-01-01

    The book on superstrings is a set of nine interviews collected for the BBC Radio 3 documentary programme entitled ''Desperately Seeking Superstrings'', which was broadcast in early 1988. The intention of the book was to give both physicists and interested non-physicists an insight into the essential ideas of string theory. The superstring theory promises to provide a unified description of all forces, all the fundamental particles of matter and space and time. As an introduction to the interviews, a brief account of quantum physics, the theory of relativity and a survey of particle physics is given. (U.K.)

  2. Superstrings

    International Nuclear Information System (INIS)

    Brink, L.

    1985-01-01

    The author investigates point-particle theories to work with the corresponding field theories. With string theories the author works in the same fashion. Field theories for superstrings have also been defined and one way to examine string theories would be to follow the same steps taken for non-abelian gauge field theories. This means that the author wants to be as fluent with field theories for strings as with field theories for point-particles. There are problems presenting themselves immediately. Field theories for string, are functional field theories which at the outset are quite badly defined. However, an oscillator basis is examined and in this way, functional expressions can be written in terms of well-defined sums. The second problem is that the field theories are only defined in the light-cone gauge so far. In the absence of a covariant formalism the author presents how to examine a field theory in the light-cone gauge. Finiteness or renormalizability, structure of counterterms, anomalies etc. in the light-cone gauge must be understood. For string theories, some great simplifications occur and even if a covariant formalism is found, it is not clear that it would be superior for explicit computations. Most of this paper sticks to the light-cone gauge and describes some of the aspects of superstring theories which make such a unifying theory of all interactions comprehensible

  3. Superstring superstars

    International Nuclear Information System (INIS)

    Neveu, A.C.

    1986-01-01

    Superstrings are seemingly irresistible for physicists in search of the ''Theory of Everything'', unifying all known forces and particles. However, as often happens in physics, superstrings were developed in a very different context, and the discovery of their remarkable properties came only slowly. (orig.).

  4. Toy superstrings

    International Nuclear Information System (INIS)

    Corvi, M.; Kostelecky, V.A.; Moxhay, P.

    1989-01-01

    Superstrings with critical dimension two and two real bosonic spacetime coordinates may serve as useful toy models for the study of string properties. We present details of several such toy superstrings including open, closed, and heterotic models. Conformal methods are used to establish the spectrum and dimensionality. The spin fields are provided and Becchi-Rouet-Stora-Tyutin- (BRST-) invariant vertex operators are constructed. Four-point tree-level and four-point one-loop amplitudes in these models are obtained. The closed and heterotic toy superstrings are shown to be modular invariant to this order

  5. Supersymmetry and Superstring Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, Mary K; Gaillard, Mary K.; Zumino, Bruno

    2008-05-05

    We briefly cover the early history of supersymmetry, describe the relation of SUSY quantum field theories to superstring theories and explain why they are considered a likely tool to describe the phenomenology of high energy particle theory beyond the Standard Model.

  6. Superstring theory

    International Nuclear Information System (INIS)

    Schwarz, J.H.

    1985-01-01

    Dual string theories, initially developed as phenomenological models of hadrons, now appear more promising as candidates for a unified theory of fundamental interactions. Type I superstring theory (SST I), is a ten-dimensional theory of interacting open and closed strings, with one supersymmetry, that is free from ghosts and tachyons. It requires that an SO(eta) or Sp(2eta) gauge group be used. A light-cone-gauge string action with space-time supersymmetry automatically incorporates the superstring restrictions and leads to the discovery of type II superstring theory (SST II). SST II is an interacting theory of closed strings only, with two D=10 supersymmetries, that is also free from ghosts and tachyons. By taking six of the spatial dimensions to form a compact space, it becomes possible to reconcile the models with our four-dimensional perception of spacetime and to define low-energy limits in which SST I reduces to N=4, D=4 super Yang-Mills theory and SST II reduces to N=8, D=4 supergravity theory. The superstring theories can be described by a light-cone-gauge action principle based on fields that are functionals of string coordinates. With this formalism any physical quantity should be calculable. There is some evidence that, unlike any conventional field theory, the superstring theories provide perturbatively renormalizable (SST I) or finite (SST II) unifications of gravity with other interactions

  7. Superstring spectroscopy

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1986-12-01

    The basic elements of string theory are presented after a brief review of the main properties of string theories, particularly the supersymmetric version. Lessons are provided on the basic quantized string, zero-point energy, the bosonic string, compactification on a torus, the superstring, the heterotic string, field compactification on an orbifold, and string compactification on an orbifold. 35 refs., 17 figs

  8. Superstring construction

    CERN Document Server

    1989-01-01

    The book includes a selection of papers on the construction of superstring theories, mainly written during the years 1984-1987. It covers ten-dimensional supersymmetric and non-supersymmetric strings, four-dimensional heterotic strings and four-dimensional type-II strings. An introduction to more recent developments in conformal field theory in relation to string construction is provided.

  9. Towards a superstring cosmology

    International Nuclear Information System (INIS)

    Taylor, J.G.

    1987-01-01

    If superstring theory is a theory of everything then it must give a satisfactory description of the very early evolution of the universe. Since the very early universe is not directly observable, then by satisfactory it is mean that the later evolution following the earlier (pre-Planck time era) phase leads to agreement with prediction for the various observable phenomena such as (B-bar B), inflation, galaxy structure, the cosmological constant (infimum), etc. Moreover it is to be hoped that the initial singularity of classical general relativistic cosmology is also avoided. It is clear that superstring theory is not yet able to tackle these problems. This paper describes what has been done so far to construct very simplified versions of string theory relevant to the early universe, and discusses the critical questions still to be answered

  10. Superstring fever

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1985-06-15

    Mathematics and particle physics have often gone their separate ways in an attitude of mutual 'benign neglect', diverging in both methodology and language. This uncomfortable gap was bridged to a unique degree at the Argonne-Fermilab-Chicago symposium on Anomalies, Geometry and Topology, which took place at Argonne pnd the University of Chicago from 28-30 March, and which highlighted the new optimism in string, and particularly superstring, theories. More than 300 theoretical physicists and mathematicians met together to discuss problems of current excitement and to report on recent progress in an atmosphere of remarkably unguarded optimism. In an overview, John Schwarz of Caltech described how superstring theories are now making dramatic strides towards achieving the ultimate goal of a unified quantum theory of all interactions including gravity.

  11. Introduction to superstrings

    International Nuclear Information System (INIS)

    Kaku, M.

    1988-01-01

    This tutorial introduces the development of, and current trends in, superstring theory, a significant and still controversial attempt to unify general relatively and quantum field theory. Stressing current areas of research activity, Introduction to Superstrings addresses topics including string field theory, multi-loops and Teichmuller spaces, conformal field theory, and four-dimensional superstrings

  12. Overproduction of cosmic superstrings

    International Nuclear Information System (INIS)

    Barnaby, Neil; Berndsen, Aaron; Cline, James M.; Stoica, Horace

    2005-01-01

    We show that the naive application of the Kibble mechanism seriously underestimates the initial density of cosmic superstrings that can be formed during the annihilation of D-branes in the early universe, as in models of brane-antibrane inflation. We study the formation of defects in effective field theories of the string theory tachyon both analytically, by solving the equation of motion of the tachyon field near the core of the defect, and numerically, by evolving the tachyon field on a lattice. We find that defects generically form with correlation lengths of order M s -1 rather than H -1 . Hence, defects localized in extra dimensions may be formed at the end of inflation. This implies that brane-antibrane inflation models where inflation is driven by branes which wrap the compact manifold may have problems with overclosure by cosmological relics, such as domain walls and monopoles

  13. Supergravities and superstrings

    International Nuclear Information System (INIS)

    Ferrara, S.

    1988-01-01

    In this paper supergavity theories emerging as the point-field limit of various superstring compactifications are considered, and the higher-order corrections to the standard supergravity Lagrangians are discussed. The structure of the effective Lagrangian for the recently constructed four-dimensional superstring models is also reported

  14. The Galilean superstring

    Energy Technology Data Exchange (ETDEWEB)

    Gomis, Joaquim [Departament de Fısica Quàntica i Astrofısica and Institut de Ciències del Cosmos (ICCUB),Universitat de Barcelona, Martıi Franquès 1, E-08028 Barcelona (Spain); Theory Group, Department of Physics, University of Texas,Austin, TX, 78712 (United States); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics,Centre for Mathematical Sciences, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2017-02-21

    The action for a Galilean superstring is found from a non-relativistic limit of the closed Green-Schwarz (GS) superstring; it has zero tension and provides an example of a massless super-Galilean system. A Wess-Zumino term leads to a topological central charge in the Galilean supersymmetry algebra, such that unitarity requires a upper bound on the total momentum. This Galilean-invariant bound, which is also implied by the classical phase-space constraints, is saturated by solutions of the superstring equations of motion that half-preserve supersymmetry. We discuss briefly the extension to the Galilean supermembrane.

  15. The Galilean superstring

    International Nuclear Information System (INIS)

    Gomis, Joaquim; Townsend, Paul K.

    2017-01-01

    The action for a Galilean superstring is found from a non-relativistic limit of the closed Green-Schwarz (GS) superstring; it has zero tension and provides an example of a massless super-Galilean system. A Wess-Zumino term leads to a topological central charge in the Galilean supersymmetry algebra, such that unitarity requires a upper bound on the total momentum. This Galilean-invariant bound, which is also implied by the classical phase-space constraints, is saturated by solutions of the superstring equations of motion that half-preserve supersymmetry. We discuss briefly the extension to the Galilean supermembrane.

  16. Introduction to superstrings

    International Nuclear Information System (INIS)

    Witten, E.

    1983-01-01

    The paper contains lecture notes on the superstring theory (in ten dimensions), which would appear at the moment to be the one real contender as a renormalizable, physically sensible quantum theory of gravity

  17. Superstrings: a theory of everything

    International Nuclear Information System (INIS)

    Anthony, S.

    1985-01-01

    The paper concerns the ''superstrings'' theory, a theory which may be capable of describing all physical phenomena. Superstring theories and its consequences are discussed, as well as quantum mechanics, general relativity and supergravity. (U.K.)

  18. Four-dimensional superstring models

    International Nuclear Information System (INIS)

    Lykken, J.D.

    1997-01-01

    These five lectures give an elementary introduction to perturbative superstring theory, superstring phenomenology, and the fermionic construction of perturbative string models. These lectures assume no prior knowledge of string theory. (author) string theory. (author)

  19. Superstrings and harmonic superspace

    International Nuclear Information System (INIS)

    Kallosh, R.E.; AN SSSR, Moscow. Fizicheskij Inst.)

    1987-01-01

    The paper on superstrings and harmonic superspace is a contribution to the book dedicated to E.S. Fradkin on his sixtieth birthday. The purpose of the paper is to propose a description of N = 2,3 superspace which could be used for the investigation of the effective d = 10 harmonic superspace corresponding to the heterotic superstring. A description is given of the structure of semi-simple Lie algebras in the Cartan-Weyl basis, as well as the general properties of the even, compact part of harmonic superspace. The main properties of the four-dimensional N = 2 SYM theory are discussed, along with the N = 3, d = 4 super Yang-Mills theory. Finally the relation between the harmonic superspace and the heterotic E 8 x E 8 superstring is examined. (U.K.)

  20. Nonabelian N=2 superstrings

    International Nuclear Information System (INIS)

    Isaev, A.P.; Ivanov, E.A.

    1990-04-01

    The Green-Schwarz covariant N=2 superstring action can be consistently deduced as the action of the Wess-Zumino-Witten (WZW) sigma model defined on the direct product of two N=1, D=10 Poincare supertranslation groups. Generalizing this result, we construct new WZW sigma models on the supergroups with a nonabelian even part and interpret them as models of superstrings moving on the supergroup manifolds. We show that these models are completely integrable and in some special cases possess fermionic k-symmetry. (author). 20 refs

  1. NSR superstring measures revisited

    International Nuclear Information System (INIS)

    Morozov, A.

    2008-01-01

    Review of remarkable progress in evaluation of NSR superstring measures, originated by E.D'Hoker and D.Phong. These recent results are presented in the old-fashioned form, what allows to highlight the options which have been overlooked in original considerations in late 1980's.

  2. Superstring inspired phenomenology

    International Nuclear Information System (INIS)

    Binetruy, P.

    1988-01-01

    Recent progress in superstring model building is reviewed with an emphasis on the general features of the models obtained. The problems associated with supersymmetry breaking and intermediate gauge symmetry breaking (M W I GUT ) are described. Finally, the phenomenology of these models is summarized, with a discussion of the role that new experimental results could play to help clearing up the above difficulties

  3. Supergravity and superstrings

    International Nuclear Information System (INIS)

    Gell-Mann, M.

    1985-01-01

    The ''standard'' SU/sub 3/ x SU/sub 2/ x U/sub 1/ theory has three independent coupling constants and numerous dimensionless parameters determining mass ratios, the weak coupling matrix, etc. While N=1 supergravity, generalizing Einstein's gravity theory, is not necessarily very divergent itself, it is terribly divergent when coupled to external N=1 supermatter, such as N=1 super-Yang-Mills theory with N=1 supermultiplets of spin one-half and spin zero. Three paths are being explored in the search for the ultimate unified theory of physics. The first path involves N > 1 supergravity in four dimensions, without external supermatter, particularly the largest such theory, N=8 supergravity, where there is no room for external supermatter. The N=8 supergravity supermultiplet itself contains all the haplons (fundamental fields of the theory). During the last couple of years Michael Green and John Schwarz have found that there are two more 10-dimensional superstring theories IIA and IIB, with only closed strings. They reduce, on truncation to the initially massless actor, to N=2A and N=2B supergravity, respectively, in ten dimensions. But the superstring theories are finite to one loop instead of divergent like the corresponding supergravities. The author discusses that IIA and IIB superstrings, when truncated to the initially massless sector and trivially reduced to four dimensions, yield N=8 supergravity. All three superstring theories, although they have the traditional description as ''S-matrix'' theories on the mass shell, can also be written as field theories (with fields as functionals of strings instead of functions of points) with local couplings. So far, the field description is not covariant. This paper discusses various superstrings theories

  4. New interactions for superstrings

    International Nuclear Information System (INIS)

    Greensite, J.; Klinkhamer, F.R.

    1987-01-01

    The supersymmetry relation {Q -A , Qsup(anti B}=2Hδsup(Aanti B) implies the existence of a new quartic vertex in the open superstring light-cone hamiltonian, if the supercharges are cubic in the string fields. Green and Schwarz have argued that this vertex almost vanishes, due to exact cancellations among fermionic operators, with perhaps a non-local interaction remaining. In this article we show that these exact cancellations do not occur for certain contributions to the anticommutator, and that new local, and possibly divergent, 4-string interactions are generated. On the basis of vacuum stability, we argue that 4-string interaction terms should also exist for closed superstring hamiltonians. (orig.)

  5. Fundamental superstrings as holograms

    International Nuclear Information System (INIS)

    Dabholkar, A.; Murthy, S.

    2007-06-01

    The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz light-cone gauge is viewed as a possible boundary hologram of the near horizon region of a small black string. For toroidally compactified strings, the hologram has global symmetries of AdS 3 x S d-1 x T 8-d ( d = 3, . . . , 8), only some of which extend to local conformal symmetries. We construct the bulk string theory in detail for the particular case of d = 3. The symmetries of the hologram are correctly reproduced from this exact worldsheet description in the bulk. Moreover, the central charge of the boundary Virasoro algebra obtained from the bulk agrees with the Wald entropy of the associated small black holes. This construction provides an exact CFT description of the near horizon region of small black holes both in Type-II and heterotic string theory arising from multiply wound fundamental superstrings. (author)

  6. Nonrelativistic superstring theories

    International Nuclear Information System (INIS)

    Kim, Bom Soo

    2007-01-01

    We construct a supersymmetric version of the critical nonrelativistic bosonic string theory [B. S. Kim, Phys. Rev. D 76, 106007 (2007).] with its manifest global symmetry. We introduce the anticommuting bc conformal field theory (CFT) which is the super partner of the βγ CFT. The conformal weights of the b and c fields are both 1/2. The action of the fermionic sector can be transformed into that of the relativistic superstring theory. We explicitly quantize the theory with manifest SO(8) symmetry and find that the spectrum is similar to that of type IIB superstring theory. There is one notable difference: the fermions are nonchiral. We further consider noncritical generalizations of the supersymmetric theory using the superspace formulation. There is an infinite range of possible string theories similar to the supercritical string theories. We comment on the connection between the critical nonrelativistic string theory and the lightlike linear dilaton theory

  7. Fundamental superstrings as holograms

    International Nuclear Information System (INIS)

    Dabholkar, Atish; Murthy, Sameer

    2008-01-01

    The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz light-cone gauge is viewed as a possible boundary hologram of the near horizon region of a small black string. For toroidally compactified strings, the hologram has global symmetries of AdS 3 x S d-1 x T 8-d (d = 3, ..., 8), only some of which extend to local conformal symmetries. We construct the bulk string theory in detail for the particular case of d = 3. The symmetries of the hologram are correctly reproduced from this exact worldsheet description in the bulk. Moreover, the central charge of the boundary Virasoro algebra obtained from the bulk agrees with the Wald entropy of the associated small black holes. This construction provides an exact CFT description of the near horizon region of small black holes both in Type-II and heterotic string theory arising from multiply wound fundamental superstrings

  8. Lectures on superstrings

    International Nuclear Information System (INIS)

    Green, M.B.

    1986-01-01

    Superstring theories have not yet been formulated in terms of a single compelling principle such as that of general relativity. However, enough is now known about the structure of these theories to justify the optimism that certain of them might be consistent quantum theories that unify gravity and the other forces. The fact that the quantum consistency of superstring theories restricts the possible ten-dimensional unifying symmetry groups to be E/sub 8/ x E/sub 8/ or SO(32) (or (Spin 32)/Z/sub 2/ which has the same algebra as SO(32)) is a novel development in particle physics. The case of E/sub 8/ x E/sub 8/ is particularly interesting since, in the process of compactification from ten to four dimensions, it can break to a realistic chiral symmetry group describing all the observed interactions and the spectrum of the known particles

  9. Introduction to superstring theory

    International Nuclear Information System (INIS)

    Nunez, Carmen

    2009-01-01

    This is a very basic introduction to the AdS/CFT correspondence. The first lecture motivates the duality between gauge theories and gravity/string theories. The next two lectures introduce the bosonic and supersymmetric string theories. The fourth lecture is devoted to study Dp-branes and finally, in the fifth lecture I discuss the two worlds: N=4 SYM in 3+1 flat dimensions and type IIB superstrings in AdS 5 x S5. (author)

  10. Supersymmetry breaking from superstrings

    International Nuclear Information System (INIS)

    Gaillard, M.K.; Lawrence Berkeley Lab., CA; California Univ., Berkeley

    1990-01-01

    The gauge hierarchy problem is briefly reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a clasical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated

  11. Introduction to superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, Carmen [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)], e-mail: carmen@iafe.uba.ar

    2009-07-01

    This is a very basic introduction to the AdS/CFT correspondence. The first lecture motivates the duality between gauge theories and gravity/string theories. The next two lectures introduce the bosonic and supersymmetric string theories. The fourth lecture is devoted to study Dp-branes and finally, in the fifth lecture I discuss the two worlds: N=4 SYM in 3+1 flat dimensions and type IIB superstrings in AdS{sub 5} x S5. (author)

  12. Supersymmetry breaking from superstrings

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1990-05-01

    The gauge hierarchy problem is briefly reviewed and a class of effective field theories obtained from superstrings is described. These are characterized by a classical symmetry, related to the space-time duality of string theory, that is responsible for the suppression of observable supersymmetry breaking effects. At the quantum level, the symmetry is broken by anomalies that provide the seed of observable supersymmetry breaking, and an acceptably large gauge hierarchy may be generated. 26 refs

  13. Superstring dark matter

    International Nuclear Information System (INIS)

    Campbell, B.A.; Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Hagelin, J.S.; Olive, K.A.

    1986-02-01

    It is argued that the lightest supersymmetric particle (LSP) emerging from the superstring theory is a mixture of neutral gauginos and matter fermions. Their mixing matrix is calculated in a plausible minimal low-energy model abstracted from the superstring and the composition of the LSP chi is exhibited. Its relic cosmological density is computed and it is found that it lies within a factor 2 of the critical density required for closure, over a wide range of possible input parameters. The flux of neutrinos from LSP annihilation in the Sun is computed and it is found that it straddles the upper bound from proton decay detectors. Acceptable fluxes are obtained if m chi is less than m/sub t/, in which case the superstring relic can have the critical density for a present Hubble expansion rate H 0 greater than or approximately equal to 50 km/s/Mpc only if m/sub t/ is greater than or approximately 40 GeV. 25 refs., 3 figs., 1 tab

  14. Priming the search for cosmic superstrings using GADGET2 simulations

    Science.gov (United States)

    Cousins, Bryce; Jia, Hewei; Braverman, William; Chernoff, David

    2018-01-01

    String theory is an extensive mathematical theory which, despite its broad explanatory power, is still lacking empirical support. However, this may change when considering the scope of cosmology, where “cosmic superstrings” may serve as observational evidence. According to string theory, these superstrings were stretched to cosmic scales in the early Universe and may now be detectable, via microlensing or gravitational radiation. Negative results from prior surveys have put some limits on superstring properties, so to investigate the parameter space more effectively, we ask: “where should we expect to find cosmic superstrings, and how many should we predict?” This research investigates these questions by simulating cosmic string behavior during structure formation in the universe using GADGET2. The sizes and locations of superstring clusters are assessed using kernel density estimation and radial correlation functions. Currently, only preliminary small-scale simulations have been performed, producing superstring clustering with low sensitivity. However, future simulations of greater magnitude will offer far higher resolution, allowing us to more precisely track superstring behavior within structures. Such results will guide future searches, most imminently those made possible by LSST and WFIRST.

  15. Effective Lagrangian from superstrings

    International Nuclear Information System (INIS)

    Cvetic, M.

    1989-01-01

    This paper presents a method to calculate the structure of the effective potential for four-dimensional vacua of the heterotic superstring with the space-time supersymmetry. The authors spell out the properties of the string vertices as defined in terms of the conformal field theory, the structure of the string amplitudes, in particular those that probe the superpotential terms, and present a method to evaluate such string amplitudes. The authors illustrate the approach by presenting certain results for the (blown-up) orbifolds

  16. Fermion masses from superstrings

    International Nuclear Information System (INIS)

    Tanaka, K.

    1986-01-01

    It is assumed that the E 8 gauge group of the E 8 x E 8 heterotic superstring can be broken into SO(10) x SU(4). The mass relations among fermions m/sub u//m/sub d/ = m/sub c//m/sub s/ = m/sub t//m/sub b/ and m/sub ν e//m/sub e/ = m/sub ν mu//m/sub μ/ = m/sub ν tau//m/sub tau/ are discussed. 18 refs

  17. Non-Critical Covariant Superstrings

    CERN Document Server

    Grassi, P A

    2005-01-01

    We construct a covariant description of non-critical superstrings in even dimensions. We construct explicitly supersymmetric hybrid type variables in a linear dilaton background, and study an underlying N=2 twisted superconformal algebra structure. We find similarities between non-critical superstrings in 2n+2 dimensions and critical superstrings compactified on CY_(4-n) manifolds. We study the spectrum of the non-critical strings, and in particular the Ramond-Ramond massless fields. We use the supersymmetric variables to construct the non-critical superstrings sigma-model action in curved target space backgrounds with coupling to the Ramond-Ramond fields. We consider as an example non-critical type IIA strings on AdS_2 background with Ramond-Ramond 2-form flux.

  18. Superstrings and geometry of superspace

    International Nuclear Information System (INIS)

    Dhar, A.

    1986-05-01

    These lectures present some recent developments in the sigma-model approach to the Green-Schwarzsuperstring. Among the topics included are: (1) interpretation of the free superstring as a flat superspace sigma-model; (2) propagation of the superstring in curved superspace; and (3) in the presence of background super Yang-Mills fields. The role of the world-sheet fermionic gauge symmetry needed to ensure consistent coupling to background fields is emphasized. 24 refs

  19. Cosmological aspects of superstring models

    International Nuclear Information System (INIS)

    Binetruy, P.

    1986-10-01

    I consider more specifically the cosmological aspects of supersymmetry breaking in ''superstring models'' (grand unified models which are believed to describe the effective theory obtained by compactification of superstring theories). The most interesting aspects are related to the presence of flat directions in the scalar potential (vacuum degeneracies). These flat directions are discussed both in the hidden sector of these models (do they give rise to inflation) and in the observable sector of quarks, leptons and Higgs particles, in connection with baryogenesis

  20. Superstrings fermionic solutions

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1990-06-01

    The solutions proposed by the superstring theory are classified and compared. In order to obtain some of the equivalences, the demonstration is based on the coincidence of the excitation spectrum and the quantum numbers from different states. The fermionic representation of the heterotical strings is discussed. The conformal invariance and the supersymmetric results extended to two dimensions are investigated. Concerning the fermionic strings, the formalism and a phenomenological solution involving three families of quarks, chiral leptons and leptons from the E 6 gauge group are presented. The equivalence between real and complex fermions is discussed. The similarity between some of the solutions of the Wess-Zumino-Witten model and the orbifolds is considered. The formal calculation program developed for reproducing the theory's low energy spectra, in the fermionic string formalism is given [fr

  1. Developments in superstring field theory

    International Nuclear Information System (INIS)

    Green, M.B.

    1987-01-01

    In this article the structure of superstring theories is outlined. The one-loop quantum superstring gauge anomalies are then described and it is shown that their absence leads to an interesting theory with gauge group SO(32). The one-loop infinities also cancel for this gauge group. The anomaly cancellation can be understood in terms of the low-energy effective supergravity-Yang-Mills field theory, from which it is shown that E 8 x E 8 is an equally good gauge group, which suggests that there should also be an interesting E 8 x E 8 superstring theory. A new type of superstring theory, known as the 'heterotic' string theory, which only describes strings with gauge groups E 8 x E 8 or SO(32) is described. Finally some very exciting prospects for obtaining a sensible description of four-dimensional physics from a ten-dimensional superstring theory with gauge group E 8 x E 8 is outlined. (author)

  2. Superstring field theory

    International Nuclear Information System (INIS)

    Green, M.B.

    1984-01-01

    Superstring field theories are formulated in terms of light-cone-gauge superfields that are functionals of string coordinates chi(sigma) and theta(sigma). The formalism used preserves only the manifest SU(4) symmetry that corresponds to rotations among six of the eight transverse directions. In type I theories, which have one ten-dimensional supersymmetry and describe both open and closed strings, there are five interaction terms of two basic kinds. One kind is a breaking or joining interaction, which is a string generalization of a cubic Yang-Mills coupling. It is relevant to both the three open-string vertex and the open-string to closed-string transition vertex. The other kind is an exchange or crossing-over interaction, which is a string generalization of a cubic gravitational coupling. All the interactions can be uniquely determined by requiring continuity of the coordinates chi(sigma) and theta(sigma) (which implies local conservation of the conjugate momenta) and by imposing the global supersymmetry algebra. Specific local operators are identified for each of the two kinds of interactions. In type II theories, which have two ten-dimensional supersymmetries and contain closed strings only, the entire interaction hamiltonian consists of a single cubic vertex. The higher-order contact terms of the N=8 supergravity theory that arises in the low-energy limit give an effective description of the exchange of massive string modes. (orig.)

  3. Torsion in superstrings

    International Nuclear Information System (INIS)

    Bars, I.; Nemeschansky, D.; Yankielowicz, S.

    1986-01-01

    In this paper the authors discuss string theories on a background manifold with torsion. In the first part, candidate vacuum configurations for ten-dimensional superstrings are discussed. The authors compactify these on M/sub 4/xK, where M/sub 4/ is four-dimensional and K some compact six-dimensional manifold. In particular they are interested in investigating the existence of solutions with non-zero torsion on K. The compactification problem is approached both from the effective field theory point of view and directly using string considerations. The second part of the talk is devoted to the construction of string theories in curved space with torsion. The authors discuss both the Neveu-Schwarz-Ramond type string and the Green-Schwarz type string. Particular emphasis is put on the resulting constraints on space-time supersymmetry in the Green-Schwarz approach. This study uses two-dimensional non-linear sigma models to describe the propagation of strings in background geometries with torsion. The background field can be understood as arising from condensation of infinite number of strings

  4. Superstring amplitudes and contact interactions

    International Nuclear Information System (INIS)

    Greensite, J.

    1987-08-01

    We show that scattering amplitudes computed from light-cone superstring field theory are divergent at tree level. The divergences can be eliminated, and supersymmetry restored, by the addition of certain counter terms to the light-cone Hamiltonian. These counter terms have the form of local contact interactions, whose existence we had previously deduced on grounds of vacuum stability, and closure of the super-Poincare algebra. The quartic contact interactions required in Type I and Type IIB superstring theories are constructed in detail. (orig.)

  5. Superstrings: a theory of everything

    International Nuclear Information System (INIS)

    Ehntoni, S.

    1986-01-01

    A possibility of developing the superstring comprehensive theory and its application for a full description of all physical phenomena, occuring in the Universe, is discussed. For this purpose principles of supersymmetric string theories and supergravity theories as well as their expected properties and effects are briefly described. The most interesting superstring theory prediction is mentioned, concerning a possibility of existence in the Universe of two matter forms with similar particles and interactions, but the second one, which is like the one we know, practically cannot be discovered by convevtional means. This quasipotential mass phenomenon is proposed as an explanation of the problem, related to the ''lacking'' mass in the Universe

  6. Analytical solution for haze values of aluminium-induced texture (AIT) glass superstrates for a-Si:H solar cells.

    Science.gov (United States)

    Sahraei, Nasim; Forberich, Karen; Venkataraj, Selvaraj; Aberle, Armin G; Peters, Marius

    2014-01-13

    Light scattering at randomly textured interfaces is essential to improve the absorption of thin-film silicon solar cells. Aluminium-induced texture (AIT) glass provides suitable scattering for amorphous silicon (a-Si:H) solar cells. The scattering properties of textured surfaces are usually characterised by two properties: the angularly resolved intensity distribution and the haze. However, we find that the commonly used haze equations cannot accurately describe the experimentally observed spectral dependence of the haze of AIT glass. This is particularly the case for surface morphologies with a large rms roughness and small lateral feature sizes. In this paper we present an improved method for haze calculation, based on the power spectral density (PSD) function of the randomly textured surface. To better reproduce the measured haze characteristics, we suggest two improvements: i) inclusion of the average lateral feature size of the textured surface into the haze calculation, and ii) considering the opening angle of the haze measurement. We show that with these two improvements an accurate prediction of the haze of AIT glass is possible. Furthermore, we use the new equation to define optimum morphology parameters for AIT glass to be used for a-Si:H solar cell applications. The autocorrelation length is identified as the critical parameter. For the investigated a-Si:H solar cells, the optimum autocorrelation length is shown to be 320 nm.

  7. String bit models for superstring

    International Nuclear Information System (INIS)

    Bergman, O.; Thorn, C.B.

    1995-01-01

    The authors extend the model of string as a polymer of string bits to the case of superstring. They mainly concentrate on type II-B superstring, with some discussion of the obstacles presented by not II-B superstring, together with possible strategies for surmounting them. As with previous work on bosonic string work within the light-cone gauge. The bit model possesses a good deal less symmetry than the continuous string theory. For one thing, the bit model is formulated as a Galilei invariant theory in (D - 2) + 1 dimensional space-time. This means that Poincare invariance is reduced to the Galilei subgroup in D - 2 space dimensions. Naturally the supersymmetry present in the bit model is likewise dramatically reduced. Continuous string can arise in the bit models with the formation of infinitely long polymers of string bits. Under the right circumstances (at the critical dimension) these polymers can behave as string moving in D dimensional space-time enjoying the full N = 2 Poincare supersymmetric dynamics of type II-B superstring

  8. String bit models for superstring

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, O.; Thorn, C.B.

    1995-12-31

    The authors extend the model of string as a polymer of string bits to the case of superstring. They mainly concentrate on type II-B superstring, with some discussion of the obstacles presented by not II-B superstring, together with possible strategies for surmounting them. As with previous work on bosonic string work within the light-cone gauge. The bit model possesses a good deal less symmetry than the continuous string theory. For one thing, the bit model is formulated as a Galilei invariant theory in (D {minus} 2) + 1 dimensional space-time. This means that Poincare invariance is reduced to the Galilei subgroup in D {minus} 2 space dimensions. Naturally the supersymmetry present in the bit model is likewise dramatically reduced. Continuous string can arise in the bit models with the formation of infinitely long polymers of string bits. Under the right circumstances (at the critical dimension) these polymers can behave as string moving in D dimensional space-time enjoying the full N = 2 Poincare supersymmetric dynamics of type II-B superstring.

  9. Scalar particles in superstring models

    International Nuclear Information System (INIS)

    Binetruy, P.

    1989-01-01

    The role played by scalar fields in superstring models is reviewed, with an emphasis on recent developments. The case of the dilaton and moduli fields is discussed in connection with the issues of spacetime duality and supersymmetry breaking. Constraints on the Higgs sector are reviewed in the different classes of models

  10. Superstring inspired models and phenomenology

    International Nuclear Information System (INIS)

    Ross, G.G.

    1987-01-01

    An investigation of the effective low-energy theory resulting from the superstring is given. The possible light gauge and chiral super-multiplet structure is considered and a specific model leading to a SU(3)xSU(2)xU(1) gauge group is presented. Phenomenological implications for such models are briefly discussed

  11. Low energy physics from superstrings

    International Nuclear Information System (INIS)

    Segre, G.C.

    1987-01-01

    The developments of the past year have resulted in growing interest in the theory of superstrings, a subject which is on the one hand extraordinarily exciting in the promise it holds for solutions of many of the outstanding problems of particle physics and on the other hand rather forbidding in the amount of new knowledge which needs to be acquired by the average theorist to understand the papers that are now being published on the recent developments. In a sense the term low energy superstrings is misleading: the work of the past fifteen years in string theory, culminating in last summer's stunning developments by Green and Schwartz have led theorists to believe a finite, consistent superstring theory can be formulated. An enormous amount of work is going on in this subject, the premise that an effective field theory in ten space-time dimensions can be obtained from the superstring theory is the start of the lectures. The lectures will cover this later stage, namely how does one proceed from the effective ten dimensional theory to an effective four dimensional theory, describing the world as we see it. 87 references, 2 tables

  12. Getting superstring amplitudes by degenerating Riemann surfaces

    International Nuclear Information System (INIS)

    Matone, Marco; Volpato, Roberto

    2010-01-01

    We explicitly show how the chiral superstring amplitudes can be obtained through factorisation of the higher genus chiral measure induced by suitable degenerations of Riemann surfaces. This powerful tool also allows to derive, at any genera, consistency relations involving the amplitudes and the measure. A key point concerns the choice of the local coordinate at the node on degenerate Riemann surfaces that greatly simplifies the computations. As a first application, starting from recent ansaetze for the chiral measure up to genus five, we compute the chiral two-point function for massless Neveu-Schwarz states at genus two, three and four. For genus higher than three, these computations include some new corrections to the conjectural formulae appeared so far in the literature. After GSO projection, the two-point function vanishes at genus two and three, as expected from space-time supersymmetry arguments, but not at genus four. This suggests that the ansatz for the superstring measure should be corrected for genus higher than four.

  13. Modified superstring in light cone gauge

    International Nuclear Information System (INIS)

    Kamimura, Kiyoshi; Tatewaki, Machiko.

    1988-01-01

    We analyze the covariant superstring theory proposed by Siegel in light cone gauge. The physical states are the direct product of those of Green-Schwarz Superstring and the additional internal space spanned by light cone spinors. At clasical level, there is no difference among observables in Siegel's modified Superstring theory (SMST) and Green-Schwarz's one (GSST). However SMST can not be quantized with additional constraints as the physical state conditions. (author)

  14. Nonabelian N=2 superstrings: Hamiltonian structure

    International Nuclear Information System (INIS)

    Isaev, A.P.; Ivanov, E.A.

    1991-04-01

    We examine the Hamiltonian structure of nonabelian N=2 superstring models which are the supergroup manifold extensions of N=2 Green-Schwarz superstring. We find the Kac-Moody and Virasoro type superalgebras of the relevant constraints and present elements of the corresponding quantum theory. A comparison with the type IIA Green-Schwarz superstring moving in a general curved 10-d supergravity background is also given. We find that nonabelian superstrings (for d=10) present a particular case of this general system corresponding to a special choice of the background. (author). 22 refs

  15. Contact interactions of closed superstrings

    International Nuclear Information System (INIS)

    Greensite, J.

    1987-07-01

    It is shown that closed light-cone superstring field theory, which is presently formulated with only cubic interaction terms, does not have a stable ground state, and that the global supersymmetry algebra is violated at second order in the coupling. Local contact interactions, of quartic (and possibly higher) order in the string fields, must be added to the light-cone Hamiltonian to restore supersymmetry and vacuum stability. (orig.)

  16. Introduction to strings and superstrings

    International Nuclear Information System (INIS)

    Traubenberg, M.R. de.

    1988-01-01

    We discuss the main features on the formulation of string theory that, in a primitive level, describe the hadronic phenomenon of duality. We also study an extension of the models of closed and strings with spin. Then, by using supersymmetry, it is formulated the theory of superstrings and heterotic strings with the aim of unify the fundamental interactions and matter. (M.W.O.) [pt

  17. Supersymmetry, supergravity and superstring models

    International Nuclear Information System (INIS)

    Ross, G.G.

    1987-01-01

    The authors discuss the structure of models with a low-energy N=1 supersymmetry. This is extended to locally supersymmetric theories and to the models resulting if physics at the Planck scale is described by the superstring. The possible new light gauge and chiral supermultiplet structures are analysed and a specific model leading to the standard SU(3) x SU(2) x U(1) model is presented. Phenomenological implications of such models are discussed

  18. Triality invariance in the N=2 superstring

    International Nuclear Information System (INIS)

    Castellani, Leonardo; Grassi, Pietro Antonio; Sommovigo, Luca

    2009-01-01

    We prove the discrete triality invariance of the N=2 NSR superstring moving in a D=2+2 target space. We find that triality holds also in the Siegel-Berkovits formulation of the selfdual superstring. A supersymmetric generalization of Cayley's hyperdeterminant, based on a quartic invariant of the SL(2|1) 3 superalgebra, is presented.

  19. Triality invariance in the N=2 superstring

    Energy Technology Data Exchange (ETDEWEB)

    Castellani, Leonardo [Dipartimento di Scienze e Tecnologie Avanzate and INFN Gruppo collegato di Alessandria, Universita del Piemonte Orientale, Via Teresa Michel 11, 15121 Alessandria (Italy)], E-mail: leonardo.castellani@mfn.unipmn.it; Grassi, Pietro Antonio [Dipartimento di Scienze e Tecnologie Avanzate and INFN Gruppo collegato di Alessandria, Universita del Piemonte Orientale, Via Teresa Michel 11, 15121 Alessandria (Italy)], E-mail: pietro.grassi@mfn.unipmn.it; Sommovigo, Luca [Dipartimento di Scienze e Tecnologie Avanzate and INFN Gruppo collegato di Alessandria, Universita del Piemonte Orientale, Via Teresa Michel 11, 15121 Alessandria (Italy)], E-mail: luca.sommovigo@mfn.unipmn.it

    2009-07-20

    We prove the discrete triality invariance of the N=2 NSR superstring moving in a D=2+2 target space. We find that triality holds also in the Siegel-Berkovits formulation of the selfdual superstring. A supersymmetric generalization of Cayley's hyperdeterminant, based on a quartic invariant of the SL(2|1){sup 3} superalgebra, is presented.

  20. Harmful axions in superstring models

    International Nuclear Information System (INIS)

    Choi, K.; Kim, J.E.

    1985-01-01

    We show in this paper that the existing superstring models, E 8 x E 8 and O(32), have the axion decay constant problem. It is either 300 GeV or 10 16 GeV, which are outside the cosmologically allowed region. It is also pointed out that the invisible axion with 10 8 GeV 12 GeV is a necessity for all theories which have an effective interaction (PHIsub(n)/Msub(Pl))F tilde below the Planck scale. (orig.)

  1. A history of the universe in a superstring model

    International Nuclear Information System (INIS)

    Maeda, K.

    1986-07-01

    A superstring theory, which is most promising candidate for a unified theory, predicts a higher-dimensional 'space-time'. Its application to cosmology, especially reconsideration of the early history of the universe, is definitely important and interesting. Here, we discuss some scenario of the universe in a superstring model. Main problems in higher-dimensional unified theories, from the cosmological point of view, are: (i) Can the 4-dim Einstein gravity be obtained, rather than the Jordan-Brans-Dicke theory? (ii) Can the 4-dim Friedmann universe (F 4 ) be realized naturally in the higher-dimensional space-time? (iii) Does inflation really occur? The answers for (i) and (ii) are 'yes' in a superstring model, as we will see soon. (iii) is still an open question, although it seems to be difficult. Taking into account a quantum tunnelling effect of the anti-symmetric tensor field H μυρ , we also show that a hierarchical bubble structure might be formed due to a series of phase transitions

  2. Superstring thermodynamics and its application to cosmology

    International Nuclear Information System (INIS)

    Matsuo, N.

    1987-01-01

    The thermodynamics of superstring theories (SST-I, SST-II) and heterotic string theory and its application to the cosmology are studied. The free energy of superstring gas is calculated in the one-loop approximation and the stability of the extra torus dimensions is discussed. Assuming that the Einstein equation dictates the evolution of the universe, we show that matter dominated universe filled with massive particles would never be realized at the beginning of the universe, contrary to the naive expectation in the superstring cosmology. (orig.)

  3. Discreteness and determinism in superstring theory

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Superstring Theory is mathematically equivalent to a completely deterministic automaton,yet the world it describes appears to be quantum mechanical. How can we reconcile these apparently conflicting observations, and what would John Bell have to say about them?

  4. Baryogenesis in superstring-motivated models

    International Nuclear Information System (INIS)

    Lazarides, G.; Panagiotakopoulos, C.; Shafi, Q.

    1988-01-01

    Baryogenesis scenarios for a variety of superstring-motivated gauge models are discussed in detail. We restrict our attention to models that possess at least one intermediate scale between the Planck and the electroweak scales. (orig.)

  5. Strings and superstrings. Electron linear colliders

    International Nuclear Information System (INIS)

    Alessandrini, V.; Bambade, P.; Binetruy, P.; Kounnas, C.; Le Duff, J.; Schwimmer, A.

    1989-01-01

    Basic string theory; strings in interaction; construction of strings and superstrings in arbitrary space-time dimensions; compactification and phenomenology; linear e+e- colliders; and the Stanford linear collider were discussed [fr

  6. Signatures for exotic quark singlets from superstrings

    International Nuclear Information System (INIS)

    Barger, V.; Deshpande, N.G.; Gunion, J.F.

    1986-09-01

    We consider various scenarios, at Superconducting Super Collider energy and luminosity, for detection of the extra colored, weak isospin singlet, charge -1/3 heavy fermion resulting from E 6 compactification in superstring theories

  7. N=1 superstrings with spontaneously broken symmetries

    International Nuclear Information System (INIS)

    Ferrara, S.

    1988-01-01

    We construct N=1 chiral superstrings with spontaneously broken gauge symmetry in four space-time dimensions. These new string solutions are obtained by a generalized coordinate-dependent Z 2 orbifold compactification of some non-chiral five-dimensional N=1 and N=2 superstrings. The scale of symmetry breaking is arbitrary (at least classically) and it can be chosen hierarchically smaller than the string scale (α') -1/2 . (orig.)

  8. Two-loop statsum of superstring

    International Nuclear Information System (INIS)

    Morozov, A.

    1987-01-01

    It is discussed, whether there is a choice of odd moduli on super-Riemnann surfaces of genus p ≥ 2, which leads to vanishing of statistical sums of of superstrings before integration over the space of even moduli. The answer is shown to be positive at least for p=2, when odd moduli are localized at ramification points. relation between various definitions of many-lopp statistical sums in superstring theory is discussed

  9. The superstring action coupled to superfield theory

    International Nuclear Information System (INIS)

    Kapustnikov, A.A.

    1991-11-01

    We propose a new superfield for d = 4, N = 1 superstring that is invariant under the general reparametrizations of d = 2, N = 2 world-sheet superspace. This action turns out to be determined in terms of properly constrained world-sheet superfields recently revealed in the framework of the PBGS (Partial Breaking of Global Supersymmetry) theory. An equivalence to the sigma model representation for heterotic d = 4 superstring is achieved by local supersymmetry gauge fixing. (author). 11 refs

  10. Introduction to strings and superstrings

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1988-01-01

    The string theory is applied in the construction of a theory which allows the coupling of the four fundamental interactions and matter. The original model of the string theory describes the hadronic phenomenon of duality. The model extension, which describes the closed strings and those with a spin, is studied. The supersymmetry and the supersymmetric partner concepts are considered, in order to obtain a superstrings theory. The supersymmetry allows the formulation of a ''supertheory'', including matter, fields and gravitation. In order to explain the mass of the observable particles, the mechanism of symmetry breaking must be taken into account. The scalar state concept, originated from the supersymmetry breaking, is analyzed. This ''supertheory'' is not entirely accepted by the scientific world [fr

  11. Inflation in a superstring model

    International Nuclear Information System (INIS)

    Maeda, K.; Pollock, M.D.; Vayonakis, C.E.

    1986-01-01

    A new type of inflation is presented in the heterotic E 8 xE 8 superstring model. The inflaton is identified with the ''Polonyi'' field tau, which is related to the radius of the internal space. Radiative corrections to the gluino-condensation potential are supposed to give rise to a suitable potential which is adjusted to vanish at the minimum by addition of a constant ΔV, whose magnitude is fixed by the requirement that density perturbations are of the right order. Reheating is due to the decay of the ''Polonyi'' field tau and/or to the production of light particles through its oscillations. The resultant constraints upon the parameters of the potential can be satisfied without excessive fine tuning. (author)

  12. Superstring cosmology for N4 = 1 → 0 superstring vacua

    International Nuclear Information System (INIS)

    Estes, J.; Kounnas, C.; Partouche, H.

    2011-01-01

    We study the cosmology of perturbative heterotic superstring theory during the radiation-like era for semi-realistic backgrounds with initial N = 1 supersymmetry. This analysis is valid for times after the Hagedorn era (or alternatively inflation era) but before the electroweak symmetry breaking transition. We find an attraction to a radiation-like era with the ratio of the supersymmetry breaking scale to temperature stabilized. This provides a dynamical mechanism for setting the supersymmetry breaking scale and its corresponding hierarchy with the Planck scale. For the internal space, we find that orbifold directions never decompactify, while toroidal directions may decompactify only when they are wrapped by certain geometrical fluxes which break supersymmetry. This suggests a mechanism for generating spatial directions during the radiation-like era. Moreover, we show that certain moduli may be stabilized during the radiation-like era with masses near the supersymmetry breaking scale. In addition, the moduli do not dominate at late times, thus avoiding the cosmological moduli problem. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Determination of the low energy spectra in the superstring theory

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1990-01-01

    There is one solution to the superstring theory in 10 dimensions (SO(32) ou E8xE8) but in a 4-dimensions space, there are plenty of solutions, so a classification is necessary. The author has used a formulation named fermionic, where the solution is easy to build and he has developed a program in terms of formal calculation (REDUCE). In a first time, this program verifies the constraints induced by the modular invariance and then reproduces the low energy spectra

  14. Detection of low tension cosmic superstrings

    Science.gov (United States)

    Chernoff, David F.; Tye, S.-H. Henry

    2018-05-01

    Cosmic superstrings of string theory differ from conventional cosmic strings of field theory. We review how the physical and cosmological properties of the macroscopic string loops influence experimental searches for these relics from the epoch of inflation. The universe's average density of cosmic superstrings can easily exceed that of conventional cosmic strings having the same tension by two or more orders of magnitude. The cosmological behavior of the remnant superstring loops is qualitatively distinct because the string tension is exponentially smaller than the string scale in flux compactifications in string theory. Low tension superstring loops live longer, experience less recoil (rocket effect from the emission of gravitational radiation) and tend to cluster like dark matter in galaxies. Clustering enhances the string loop density with respect to the cosmological average in collapsed structures in the universe. The enhancement at the Sun's position is ~ 105. We develop a model encapsulating the leading order string theory effects, the current understanding of the string network loop production and the influence of cosmological structure formation suitable for forecasting the detection of superstring loops via optical microlensing, gravitational wave bursts and fast radio bursts. We evaluate the detection rate of bursts from cusps and kinks by LIGO- and LISA-like experiments. Clustering dominates rates for G μ 10‑14.2 (LIGO cusp), G μ>10‑15 (LISA cusp) and G μ>10‑ 14.1 (LISA kink).

  15. NSR superstring measures in genus 5

    International Nuclear Information System (INIS)

    Dunin-Barkowski, Petr; Sleptsov, Alexey; Stern, Abel

    2013-01-01

    Currently there are two proposed ansätze for NSR superstring measures: the Grushevsky ansatz and the OPSMY ansatz, which for genera g⩽4 are known to coincide. However, neither the Grushevsky nor the OPSMY ansatz leads to a vanishing two-point function in genus four, which can be constructed from the genus five expressions for the respective ansätze. This is inconsistent with the known properties of superstring amplitudes. In the present paper we show that the Grushevsky and OPSMY ansätze do not coincide in genus five. Then, by combining these ansätze, we propose a new ansatz for genus five, which now leads to a vanishing two-point function in genus four. We also show that one cannot construct an ansatz from the currently known forms in genus 6 that satisfies all known requirements for superstring measures

  16. An overview of superstring theory. 26

    International Nuclear Information System (INIS)

    Sharatchandra, H.S.

    1989-01-01

    In recent years the theory of superstrings (SST) has been a candidate for the Theory of Everything (TOE). Strings are idealized one-dimensional extended objects, a natural generalization of relativistic point particles. With SST one may have a quantum field theory whose internal consistency moreover requires a unique number of spacetime dimensions 26 for bosonic strings and 10 for superstrings. This is the subject of this chapter which proceeds from dual models and Veneziano formula to a discussion of the relativistic string. light cone and Hamiltonian quantization is followed by a treatment of Lorentz covariance and the spectrum of string excitations. The field theory limit of interacting strings leads to higher derivative corrections to the Einstein action. It ends with a discussion of superstrings, current problems and future prospects. (author). 5 refs.; 7 figs

  17. Tensionless superstrings: view from the worldsheet

    Energy Technology Data Exchange (ETDEWEB)

    Bagchi, Arjun [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Indian Institute of Technology Kanpur,Kanpur 208016 (India); Chakrabortty, Shankhadeep [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Parekh, Pulastya [Indian Institute of Technology Kanpur,Kanpur 208016 (India); Indian Institute of Science Education and Research,Dr Homi Bhabha Road, Pashan. Pune 411008, Iindia (India)

    2016-10-21

    In this brief note, we show that the residual symmetries that arise in the analysis of the tensionless superstrings in the equivalent of the conformal gauge is (a trivial extension of) the recently discovered 3d Super Bondi-Metzner-Sachs algebra, discussed in the context of asymptotic symmetries of 3d Supergravity in flat-spacetimes. This helps us uncover a limiting approach to the construction of the tensionless superstring from the point of view of the worldsheet, analogous to the one we had adopted earlier for the closed tensionless bosonic string.

  18. On vanishing of vacuum energy for superstrings

    International Nuclear Information System (INIS)

    Morozov, A.; Perelomov, A.

    1986-01-01

    Hypothesis, concerning the structure of formulae for vacuum diagrams in the first-quantized superstring theory is proposed. The analytical measure in the integration over moduli space is proportional to the sum over spin structures on Riemann surfaces and vanishes because of the Riemann identities for Θ-constants

  19. Towards Matrix Models in IIB Superstrings

    OpenAIRE

    Olesen, P.

    1997-01-01

    I review the properties of a matrix action of relevance for IIB superstrings. This model generalizes the action proposed by Ishibashi, Kawai, Kitazawa, and Tsuchiya by introducing an auxillary field Y, which is the matrix version of the auxillary field g in the Schild action.

  20. On the singularities of massive superstring amplitudes

    NARCIS (Netherlands)

    Foda, O.

    1987-01-01

    Superstring one-loop amplitudes with massive external states are shown to be in general ill-defined due to internal on-shell propagators. However, we argue that since any massive string state (in the uncompactified theory) has a finite lifetime to decay into massless particles, such amplitudes are

  1. Thin film silicon modules on plastic superstrates

    NARCIS (Netherlands)

    Rath, J.K.; Liu, Y; Borreman, A.; Hamers, E.A.G.; Schlatmann, R.; Jongerden, G.J.; Schropp, R.E.I.

    2008-01-01

    The aim of this research is to fabricate high efficiency a-Si/μc-Si tandem solar cell modules on flexible (polymer) superstrates using the Helianthos concept. As a first step we began by depositing the top cell which contains an amorphous silicon (a-Si:H) i-layer of 350 nm made by VHF PECVD at 50

  2. Non-critical pure spinor superstrings

    International Nuclear Information System (INIS)

    Adam, Ido; Grassi, Pietro Antonio; Mazzucato, Luca; Oz, Yaron; Yankielowicz, Shimon

    2007-01-01

    We construct non-critical pure spinor superstrings in two, four and six dimensions. We find explicitly the map between the RNS variables and the pure spinor ones in the linear dilaton background. The RNS variables map onto a patch of the pure spinor space and the holomorphic top form on the pure spinor space is an essential ingredient of the mapping. A basic feature of the map is the requirement of doubling the superspace, which we analyze in detail. We study the structure of the non-critical pure spinor space, which is different from the ten-dimensional one, and its quantum anomalies. We compute the pure spinor lowest lying BRST cohomology and find an agreement with the RNS spectra. The analysis is generalized to curved backgrounds and we construct as an example the non-critical pure spinor type IIA superstring on AdS 4 with RR 4-form flux

  3. Local discrete symmetries from superstring derived models

    International Nuclear Information System (INIS)

    Faraggi, A.E.

    1996-10-01

    Discrete and global symmetries play an essential role in many extensions of the Standard Model, for example, to preserve the proton lifetime, to prevent flavor changing neutral currents, etc. An important question is how can such symmetries survive in a theory of quantum gravity, like superstring theory. In a specific string model the author illustrates how local discrete symmetries may arise in string models and play an important role in preventing fast proton decay and flavor changing neutral currents. The local discrete symmetry arises due to the breaking of the non-Abelian gauge symmetries by Wilson lines in the superstring models and forbids, for example dimension five operators which mediate rapid proton decay, to all orders of nonrenormalizable terms. In the context of models of unification of the gauge and gravitational interactions, it is precisely this type of local discrete symmetries that must be found in order to insure that a given model is not in conflict with experimental observations

  4. Effective gluon interactions from superstring disk amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Oprisa, D.

    2006-05-15

    In this thesis an efficient method for the calculation of the N-point tree-level string amplitudes is presented. Furthermore it is shown that the six-gluon open-superstring disk amplitude can be expressed by a basis of six triple hypergeometric functions, which encode the full {alpha}' dependence. In this connection material for obtaining the {alpha}' expansion of these functions is derived. Hereby many Euler-Zagier sums are calculated including multiple harmonic series. (HSI)

  5. On the singularities of massive superstring amplitudes

    International Nuclear Information System (INIS)

    Foda, O.

    1987-01-01

    Superstring one-loop amplitudes with massive external states are shown to be in general ill-defined due to internal on-shell propagators. However, we argue that since any massive string state (in the uncompactified theory) has a finite lifetime to decay into massless particles, such amplitudes are not terms in the perturbative expansion of physical S-matrix elements: These can be defined only with massless external states. Consistent massive amplitudes repuire an off-shell formalism. (orig.)

  6. On the singularities of massive superstring amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O.

    1987-06-04

    Superstring one-loop amplitudes with massive external states are shown to be in general ill-defined due to internal on-shell propagators. However, we argue that since any massive string state (in the uncompactified theory) has a finite lifetime to decay into massless particles, such amplitudes are not terms in the perturbative expansion of physical S-matrix elements: These can be defined only with massless external states. Consistent massive amplitudes repuire an off-shell formalism.

  7. On the infinities of closed superstring amplitudes

    International Nuclear Information System (INIS)

    Restuccia, A.; Taylor, J.G.

    1988-01-01

    The authors present an analysis of possible infinities that may be present in uncompactified multi-loop heterotic and type II superstring amplitudes constructed, without use of the short-string limit, in the light-cone gauge, and with use of a closed [10]-SUSY field theory algebra. Various types of degenerations of the integrand are discussed on the string worldsheet. No infinities are found, modulo (for type II) a particular identity for Green's functions

  8. Two-loop superstring partition function

    International Nuclear Information System (INIS)

    Morozov, A.Y.

    1988-01-01

    Is it possible to choose the odd moduli on super-Riemann surfaces of genus p≥2 in such a way that the corresponding contributions to the superstring partition function vanish before the integration over the space of the moduli? It is shown that, at least for p = 2, the answer to this question is affirmative, and in this case the odd moduli should be localized at branch points

  9. Torsion and geometrostasis in covariant superstrings

    International Nuclear Information System (INIS)

    Zachos, C.

    1985-01-01

    The covariant action for freely propagating heterotic superstrings consists of a metric and a torsion term with a special relative strength. It is shown that the strength for which torsion flattens the underlying 10-dimensional superspace geometry is precisely that which yields free oscillators on the light cone. This is in complete analogy with the geometrostasis of two-dimensional sigma-models with Wess-Zumino interactions. 13 refs

  10. Effective gluon interactions from superstring disk amplitudes

    International Nuclear Information System (INIS)

    Oprisa, D.

    2006-05-01

    In this thesis an efficient method for the calculation of the N-point tree-level string amplitudes is presented. Furthermore it is shown that the six-gluon open-superstring disk amplitude can be expressed by a basis of six triple hypergeometric functions, which encode the full α' dependence. In this connection material for obtaining the α' expansion of these functions is derived. Hereby many Euler-Zagier sums are calculated including multiple harmonic series. (HSI)

  11. Torsion and geometrostasis in covariant superstrings

    Energy Technology Data Exchange (ETDEWEB)

    Zachos, C.

    1985-01-01

    The covariant action for freely propagating heterotic superstrings consists of a metric and a torsion term with a special relative strength. It is shown that the strength for which torsion flattens the underlying 10-dimensional superspace geometry is precisely that which yields free oscillators on the light cone. This is in complete analogy with the geometrostasis of two-dimensional sigma-models with Wess-Zumino interactions. 13 refs.

  12. Anomalies in Witten's NSR superstring field theory

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Medvedev, P.B.

    1988-01-01

    The action of Witten's NSR superstring field theory if shown to depend on the regularization being choosen to define its value on non-smooth states that are generated by supertransformation. The necessity of additional regularization originates from the appearance of products of picture-changing operators in coincident points. Two different regularization are described, one corresponding to Witten's scheme and the other to the scheme based on the notion of truncated fields

  13. Compactification of Superstrings and Chain or Oriented Strings in Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Robert O.

    2000-04-10

    Superstring theories command the study of their various possible compactifications, and their consequence physics. Thus, the role of topology is likely to be far more central, in particular in ten-dimensional physics. Topological invariants on a chain of oriented strings in interaction are discussed. Attempts to link superstrings with the reality of the physical world in four dimensions are discussed.

  14. The superstring: theory of everything, or of nothing

    International Nuclear Information System (INIS)

    Ellis, J.

    1986-01-01

    Superstring models excite theoretical physicists because they may unite the four fundamental forces. These theories are formulated in a ten-dimensional world of extraordinarily high energies. Recent work indicates how superstrings may nevertheless relate to our four-dimensional world and to laboratory experiments. (author)

  15. Gauge coupling unification in superstring derived standard-like models

    International Nuclear Information System (INIS)

    Faraggi, A.E.

    1992-11-01

    I discuss gauge coupling unification in a class of superstring standard-like models, which are derived in the free fermionic formulation. Recent calculations indicate that the superstring unification scale is at O(10 18 GeV) while the minimal supersymmetric standard model is consistent with LEP data if the unification scale is at O(10 16 )GeV. A generic feature of the superstring standard-like models is the appearance of extra color triplets (D,D), and electroweak doublets (l,l), in vector-like representations, beyond the supersymmetric standard model. I show that the gauge coupling unification at O(10 18 GeV) in the superstring standard-like models can be consistent with LEP data. I present an explicit standard-like model that can realize superstring gauge coupling unification. (author)

  16. Superstring threshold corrections to Yukawa couplings

    International Nuclear Information System (INIS)

    Antoniadis, I.; Taylor, T.R.

    1992-12-01

    A general method of computing string corrections to the Kaehler metric and Yukawa couplings is developed at the one-loop level for a general compactification of the heterotic superstring theory. It also provides a direct determination of the so-called Green-Schwarz term. The matter metric has an infrared divergent part which reproduces the field-theoretical anomalous dimensions, and a moduli-dependent part which gives rise to threshold corrections in the physical Yukawa couplings. Explicit expressions are derived for symmetric orbifold compactifications. (author). 20 refs

  17. Supersymmetry in open superstring field theory

    Energy Technology Data Exchange (ETDEWEB)

    Erler, Theodore [Arnold Sommerfeld Center, Ludwig-Maximilians University,Theresienstrasse 37, 80333 Munich (Germany)

    2017-05-19

    We realize the 16 unbroken supersymmetries on a BPS D-brane as invariances of the action of the corresponding open superstring field theory. We work in the small Hilbert space approach, where a symmetry of the action translates into a symmetry of the associated cyclic A{sub ∞} structure. We compute the supersymmetry algebra, being careful to disentangle the components which produce a translation, a gauge transformation, and a symmetry transformation which vanishes on-shell. Via the minimal model theorem, we illustrate how supersymmetry of the action implies supersymmetry of the tree level open string scattering amplitudes.

  18. Quantization of Green-Schwarz superstring

    International Nuclear Information System (INIS)

    Kallosh, R.E.

    1987-04-01

    The problem of quantization of superstrings is traced back to the nil-potency of gauge generators of the first-generation ghosts. The quantization of such theories is performed. The novel feature of this quantization is the freedom in choosing the number of ghost generations as well as gauge conditions. As an example, we perform quantization of heterotic string in a gauge, which preserves space-time supersymmetry. The equations of motion are those of a free theory. (author). 12 refs, 2 figs

  19. Covariant super reggeon calculus for superstrings

    International Nuclear Information System (INIS)

    Petersen, J.L.; Sidenius, J.R.; Tollsten, A.K.

    1988-07-01

    A previously developed formalism for the bosonic string is extended to the Neveu-Schwarz-Ramond string using 2-d superspace techniques throughout. 3-string vertices for NS- and R-strings are constructed, sewing rules developed, and the technique of quasi-superconformal modes is set up for constructing the measure on super moduli space. Symmetries, such as superconformal invariance and BRST-invariance, are guaranteed ab initio. Picture changing and bosonization are avoided. Examples are given. The formalism should allow a superstring loop calculus based on supermoduli. Results concerning the ensuing super-Schottky description are given. (orig.)

  20. Quarks and leptons from orbifolded superstring

    International Nuclear Information System (INIS)

    Choi, K.S.; Kim, J.E.

    2006-01-01

    This book seeks to be a guidebook on the journey towards the minimal supersymmetric standard model down the orbifold road. It takes the viewpoint that the chirality of matter fermions is an essential aspect that orbifold compactification allows to derive from higher-dimensional string theories in a rather straight-forward manner. Halfway between a textbook and a tutorial review, ''Quarks and Leptons from Orbifolded Superstring'' is intended for the graduate student and particle phenomenologist wishing to get acquainted with this field. (orig.)

  1. Magnetic flux tube models in superstring theory

    CERN Document Server

    Russo, Jorge G

    1996-01-01

    Superstring models describing curved 4-dimensional magnetic flux tube backgrounds are exactly solvable in terms of free fields. We consider the simplest model of this type (corresponding to `Kaluza-Klein' Melvin background). Its 2d action has a flat but topologically non-trivial 10-dimensional target space (there is a mixing of angular coordinate of the 2-plane with an internal compact coordinate). We demonstrate that this theory has broken supersymmetry but is perturbatively stable if the radius R of the internal coordinate is larger than R_0=\\sqrt{2\\a'}. In the Green-Schwarz formulation the supersymmetry breaking is a consequence of the presence of a flat but non-trivial connection in the fermionic terms in the action. For R R/2\\a' there appear instabilities corresponding to tachyonic winding states. The torus partition function Z(q,R) is finite for R > R_0 (and vanishes for qR=2n, n=integer). At the special points qR=2n (2n+1) the model is equivalent to the free superstring theory compactified on a circle...

  2. Cutkosky rules for superstring field theory

    International Nuclear Information System (INIS)

    Pius, Roji; Sen, Ashoke

    2016-01-01

    Superstring field theory expresses the perturbative S-matrix of superstring theory as a sum of Feynman diagrams each of which is manifestly free from ultraviolet divergences. The interaction vertices fall off exponentially for large space-like external momenta making the ultraviolet finiteness property manifest, but blow up exponentially for large time-like external momenta making it impossible to take the integration contours for loop energies to lie along the real axis. This forces us to carry out the integrals over the loop energies by choosing appropriate contours in the complex plane whose ends go to infinity along the imaginary axis but which take complicated form in the interior navigating around the various poles of the propagators. We consider the general class of quantum field theories with this property and prove Cutkosky rules for the amplitudes to all orders in perturbation theory. Besides having applications to string field theory, these results also give an alternative derivation of Cutkosky rules in ordinary quantum field theories.

  3. ICTP lectures on covariant quantization of the superstring

    International Nuclear Information System (INIS)

    Berkovits, N.

    2003-01-01

    These ICTP Trieste lecture notes review the pure spinor approach to quantizing the superstring with manifest D=10 super-Poincare invariance. The first section discusses covariant quantization of the superparticle and gives a new proof of equivalence with the Brink-Schwarz superparticle. The second section discusses the superstring in a flat background and shows how to construct vertex operators and compute tree amplitudes in a manifestly super-Poincare covariant manner. And the third section discusses quantization of the superstring in curved backgrounds which can include Ramond-Ramond flux. (author)

  4. Higher point spin field correlators in D=4 superstring theory

    International Nuclear Information System (INIS)

    Haertl, D.; Schlotterer, O.; Stieberger, S.

    2010-01-01

    Calculational tools are provided allowing to determine general tree-level scattering amplitudes for processes involving bosons and fermions in heterotic and superstring theories in four space-time dimensions. We compute higher-point superstring correlators involving massless four-dimensional fermionic and spin fields. In D=4 these correlators boil down to a product of two pure spin field correlators of left- and right-handed spin fields. This observation greatly simplifies the computation of such correlators. The latter are basic ingredients to compute multi-fermion superstring amplitudes in D=4. Their underlying fermionic structure and the fermionic couplings in the effective action are determined by these correlators.

  5. ICTP lectures on covariant quantization of the superstring

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, N [Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo, SP (Brazil)

    2003-08-15

    These ICTP Trieste lecture notes review the pure spinor approach to quantizing the superstring with manifest D=10 super-Poincare invariance. The first section discusses covariant quantization of the superparticle and gives a new proof of equivalence with the Brink-Schwarz superparticle. The second section discusses the superstring in a flat background and shows how to construct vertex operators and compute tree amplitudes in a manifestly super-Poincare covariant manner. And the third section discusses quantization of the superstring in curved backgrounds which can include Ramond-Ramond flux. (author)

  6. Scattering amplitudes in open superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Schlotterer, Oliver

    2011-07-15

    The present thesis deals with the theme field of the scattering amplitudes in theories of open superstrings. Especially two different formalisms for the handling of superstrings are introduced and applied for the calaculation of tree-level amplitudes - the Ramond- Neveu-Schwarz (RNS) and the Pure-Spinor (PS) formalism. The RNS approach is proved as flexible in order to describe compactification of the initially ten flat space-time dimensions to four dimensions. We solve the technical problems, which result from the interacting basing world-sheet theory with conformal symmetry. This is used to calculate phenomenologically relevant scattering amplitudes of gluons and quarks as well as production rates of massive harmonic vibrations, which were already identified as virtual exchange particles on the massless level. In the case of a low string mass scale in the range of some Tev the string-specific signatures in parton collisions can be observed in the near future in the LHC experiment at CERN and indicated as first experimental proof of the string theory. THose string effects occur universally for a wide class of string ground states respectively internal geometries and represent an elegant way to avoid the so-called landscape problem of the string theory. A further theme complex in this thesis is based on the PS formalism, which allows a manifestly supersymmetric treatment of scattering amplitudes in ten space-time dimension with sixteen supercharges. We introduce a family of superfields, which occur in massless amplitudes of the open string and can be naturally identified with diagrams of three-valued knots. Thereby we reach not only a compact superspace representation of the n-point field-theory amplitude but can also write the complete superstring n-point amplitude as minimal linear combination of partial amplitudes of the field theory as well as hypergeometric functions. The latter carry the string effects and are analyzed from different perspectives, above all

  7. Scattering amplitudes in open superstring theory

    International Nuclear Information System (INIS)

    Schlotterer, Oliver

    2011-01-01

    The present thesis deals with the theme field of the scattering amplitudes in theories of open superstrings. Especially two different formalisms for the handling of superstrings are introduced and applied for the calaculation of tree-level amplitudes - the Ramond- Neveu-Schwarz (RNS) and the Pure-Spinor (PS) formalism. The RNS approach is proved as flexible in order to describe compactification of the initially ten flat space-time dimensions to four dimensions. We solve the technical problems, which result from the interacting basing world-sheet theory with conformal symmetry. This is used to calculate phenomenologically relevant scattering amplitudes of gluons and quarks as well as production rates of massive harmonic vibrations, which were already identified as virtual exchange particles on the massless level. In the case of a low string mass scale in the range of some Tev the string-specific signatures in parton collisions can be observed in the near future in the LHC experiment at CERN and indicated as first experimental proof of the string theory. THose string effects occur universally for a wide class of string ground states respectively internal geometries and represent an elegant way to avoid the so-called landscape problem of the string theory. A further theme complex in this thesis is based on the PS formalism, which allows a manifestly supersymmetric treatment of scattering amplitudes in ten space-time dimension with sixteen supercharges. We introduce a family of superfields, which occur in massless amplitudes of the open string and can be naturally identified with diagrams of three-valued knots. Thereby we reach not only a compact superspace representation of the n-point field-theory amplitude but can also write the complete superstring n-point amplitude as minimal linear combination of partial amplitudes of the field theory as well as hypergeometric functions. The latter carry the string effects and are analyzed from different perspectives, above all

  8. Superstrings and the search for the theory of everything

    International Nuclear Information System (INIS)

    Peat, D.

    1988-01-01

    This book contains the following chapters: A Crisis in Physics; From Points to Strings; Nambu's String Theory; Grand Unification; Superstrings; Heterotic Strings: Two Dimensions in One; From Spinors to Twistors; Twistor Space; Twistor Gravity; and Into Deep Waters

  9. 2002 Spring school on superstrings and related matters

    Energy Technology Data Exchange (ETDEWEB)

    Bachas, C [ENS, Paris (France); Gava, E [INFN, Trieste (Italy); [Abdus Salam ICTP, Trieste (Italy); Maldacena, J [Harvard University, Cambridge (United States); Narain, K S; Randjbar-Daemi, S [Abdus Salam ICTP, Trieste (Italy)

    2003-08-15

    This CD contains the lecture notes given at the Spring School on Superstrings and related Matters, held at the Abdus Salam International Centre for Theoretical Physics from 18 to 26 March 2002. It contains lectures about M theory, G{sub 2}-manifolds and four dimensional physics, covariant quantization of the superstring, mirror symmetry, strings in flat space and plane waves from N=4 super Yang Mills, phenomenological aspects of D-branes and open string star algebra.

  10. 2002 Spring school on superstrings and related matters

    International Nuclear Information System (INIS)

    Bachas, C.; Gava, E.; Maldacena, J.; Narain, K.S.; Randjbar-Daemi, S.

    2003-01-01

    This CD contains the lecture notes given at the Spring School on Superstrings and related Matters, held at the Abdus Salam International Centre for Theoretical Physics from 18 to 26 March 2002. It contains lectures about M theory, G 2 -manifolds and four dimensional physics, covariant quantization of the superstring, mirror symmetry, strings in flat space and plane waves from N=4 super Yang Mills, phenomenological aspects of D-branes and open string star algebra

  11. Open superstring field theory on the restricted Hilbert space

    International Nuclear Information System (INIS)

    Konopka, Sebastian; Sachs, Ivo

    2016-01-01

    It appears that the formulation of an action for the Ramond sector of open superstring field theory requires to either restrict the Hilbert space for the Ramond sector or to introduce auxiliary fields with picture −3/2. The purpose of this note is to clarify the relation of the restricted Hilbert space with other approaches and to formulate open superstring field theory entirely in the small Hilbert space.

  12. Constraints on cosmic superstrings from Kaluza-Klein emission.

    Science.gov (United States)

    Dufaux, Jean-François

    2012-07-06

    Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.

  13. A search for exact superstring vacua

    CERN Document Server

    Peterman, Andreas; Zichichi, Antonino

    1994-01-01

    We investigate $2d$ sigma-models with a $2+N$ dimensional Minkowski signature target space metric and Killing symmetry, specifically supersymmetrized, and see under which conditions they might lead to corresponding exact string vacua. It appears that the issue relies heavily on the properties of the vector $M_{\\mu}$, a reparametrization term, which needs to possess a definite form for the Weyl invariance to be satisfied. We give, in the $n = 1$ supersymmetric case, two non-renormalization theorems from which we can relate the $u$ component of $M_{\\mu}$ to the $\\beta^G_{uu}$ function. We work out this $(u,u)$ component of the $\\beta^G$ function and find a non-vanishing contribution at four loops. Therefore, it turns out that at order $\\alpha^{\\prime 4}$, there are in general non-vanishing contributions to $M_u$ that prevent us from deducing superstring vacua in closed form.

  14. Quark soup al dente: applied superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Myers, R C; Vazquez, S E [Perimeter Institute for Theoretical Physics, 31 Caroline St N, Waterloo, Ontario N2 L 2Y5 (Canada)], E-mail: rmyers@perimeterinstitute.ca, E-mail: svazquez@perimeterinstitute.ca

    2008-06-07

    In recent years, experiments have discovered an exotic new state of matter known as the strongly coupled quark-gluon plasma (sQGP). At present, it seems that standard theoretical tools, such as perturbation theory and lattice gauge theory, are poorly suited to understand this new phase. However, recent progress in superstring theory has provided us with a theoretical laboratory for studying very similar systems of strongly interacting hot non-Abelian plasmas. This surprising new perspective extracts the fluid properties of the sQGP from physical processes in a black hole spacetime. Hence we may find the answers to difficult particle physics questions about the sQGP from straightforward calculations in classical general relativity.

  15. Introduction to string and superstring theory II

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1987-03-01

    Conformal field theory is reviewed, then conformal invariance is used to rederive the basic results on the embedding dimensionality for bosonic and fermionic strings. The spectrum of the bosonic and the computation of scattering amplitudes are discussed. The formalism used is extended to clarify the origin of Yang-Mills gauge invariance in the open bosonic string theory. The question of the general-coordinate gauge invariance of string theory is addressed, presenting two disparate viewpoints on this question. A brief introduction is then given of the reduction from the idealized string theory in 10 extended dimensions to more realistic solutions in which all but 4 of these dimensions are compactified. The state of knowledge about the space-time supersymmetry of the superstring from the covariant viewpoint is outlined. An approach for identifying possible 6-dimensional spaces which might represent the form of the compact dimensions is discussed, and the orbifold scheme of compactification is presented. 77 refs., 18 figs

  16. A superstring field theory for supergravity

    Science.gov (United States)

    Reid-Edwards, R. A.; Riccombeni, D. A.

    2017-09-01

    A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.

  17. On inflation in the heterotic superstring model

    International Nuclear Information System (INIS)

    Maeda, K.; Pollock, M.D.

    1985-11-01

    We consider the possibility of achieving inflation in the field-theory limit of the E 8 xE 8 superstring model. We show that neither type I inflation nor inflation due to a SUSY-breaking gaugino-condensation potential, is possible, essentially because of the absence of free dimensionless parameters. Kaluza-Klein type inflation is ruled out because the internal space is Ricci flat. The occurrence of type II inflation (due to some gauge singlet 'inflaton' field phi) depends upon the form of the superpotential F and of the Kaehler potential G, but this also seems not to be possible, unless the SU(n,1) symmetry can be broken in a particular way. Hence, some new type of compactification scheme may be called for, or a different type of inflation

  18. Introduction to string and superstring theory II

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1987-03-01

    Conformal field theory is reviewed, then conformal invariance is used to rederive the basic results on the embedding dimensionality for bosonic and fermionic strings. The spectrum of the bosonic and the computation of scattering amplitudes are discussed. The formalism used is extended to clarify the origin of Yang-Mills gauge invariance in the open bosonic string theory. The question of the general-coordinate gauge invariance of string theory is addressed, presenting two disparate viewpoints on this question. A brief introduction is then given of the reduction from the idealized string theory in 10 extended dimensions to more realistic solutions in which all but 4 of these dimensions are compactified. The state of knowledge about the space-time supersymmetry of the superstring from the covariant viewpoint is outlined. An approach for identifying possible 6-dimensional spaces which might represent the form of the compact dimensions is discussed, and the orbifold scheme of compactification is presented. 77 refs., 18 figs. (LEW)

  19. On the dynamics of superstring compactification

    Science.gov (United States)

    Pollock, M. D.

    2018-05-01

    Compactification of the ten-dimensional heterotic superstring theory to four dimensions gives rise to two moduli potentials VA, VB, the positive semi-definiteness of which places constraints on the Euler characteristic \\bar{χ} of the internal space \\bar{g}_{μν}(y^{ξ}) and the adiabatic index γ of the effective matter source of energy-density ρ and pressure p = (γ -1)ρ that generates the physical four-space g_{ij}(xk), namely \\bar{χ} 0, 1 ≤ γ ≤ 4/3. Here, we show how fermion-bilinear condensation in the internal space, first put forward by Helayël-Neto and Smith, determines the field \\tilde{β} ≡ A_r B_r3, thus reducing the moduli space to a single canonical field \\tilde{σ}=2σB with a potential ˜ , which is positive semi-definite under the same conditions that ensure positive semi-definiteness of VA, VB, and has a minimum at a value of \\tilde{β} that is approximately constant far from the Planck era at t ≫ t_P. The fields σA, σB, which are canonically normalized in the zero-slope limit, are modified by contributions originating from the higher-derivative gravitational terms α^' \\hatR_E2 and α^' 3} \\hatR4, but the associated kinetic energy remains positive for times t ≳ t_P/2, guaranteeing classical stability of the solution, since the generalized indeterminacy principle implies a minimum physically measurable time t0 ≈ 50 t_P for the superstring theory.

  20. Consistent superstrings as solutions of the D=26 bosonic string theory

    International Nuclear Information System (INIS)

    Casher, A.; Englert, F.; Nicolai, H.; Taormina, A.

    1985-01-01

    Consistent closed ten-dimensional superstrings, i.e. the two N=2 superstrings, are contained in the 26-dimensional bosonic closed string theory. The latter thus appears as the fundamental string theory. (orig.)

  1. Comment on non-renormalization theorem in the four dimensional superstrings

    International Nuclear Information System (INIS)

    Soda, Jiro; Nakazawa, Naohito; Sakai, Kenji; Ojima, Shuichi.

    1987-10-01

    We discuss non-renormalization theorem in the context of the four dimensional superstrings. We explicitly demonstrate that the graviton 3-point one-loop amplitude does not vanish in contrast to the ten dimensional superstring theories. (author)

  2. Can the superstring inspire the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.A.

    1988-02-01

    We discuss general features of models in which the E/sub 8/xE'/sub 8/ heterotic superstring is compactified on a specific Calabi-Yau manifold. The gauge group of rank-6 in four dimensions is supposed to be broken down at an intermediate scale m/sub I/ to the standard model group SU(3)/sub C/ x SU(2)/sub L/ x U(1)/sub Y/, as a result of two neutral scalar fields acquiring large vacuum expectations (vev's) in one of many flat directions of the effective potential. We find that it is difficult to generate such an intermediate scale by radiative symmetry breaking, whilst such models have prima facie problems with baryon decay mediated by massive particles and with non-perturbative behaviour of the gauge couplings, unless m/sub I/ > or approx. 10/sup 16/ GeV. Rapid baryon decay mediated by light particles, large neutrino masses, other ..delta..L not = 0 processes and flavour-changing neutral currents are generic features of these models. We illustrate these observations with explicit calculations in a number of different models given by vev's in different flat directions.

  3. Can the superstring inspire the standard model?

    International Nuclear Information System (INIS)

    Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.A.

    1988-01-01

    We discuss general features of models in which the E 8 xE' 8 heterotic superstring is compactified on a specific Calabi-Yau manifold. The gauge group of rank-6 in four dimensions is supposed to be broken down at an intermediate scale m I to the standard model group SU(3) C x SU(2) L x U(1) Y , as a result of two neutral scalar fields acquiring large vacuum expectations (vev's) in one of many flat directions of the effective potential. We find that it is difficult to generate such an intermediate scale by radiative symmetry breaking, whilst such models have prima facie problems with baryon decay mediated by massive particles and with non-perturbative behaviour of the gauge couplings, unless m I > or approx. 10 16 GeV. Rapid baryon decay mediated by light particles, large neutrino masses, other ΔL ≠ 0 processes and flavour-changing neutral currents are generic features of these models. We illustrate these observations with explicit calculations in a number of different models given by vev's in different flat directions. (orig.)

  4. Supersymmetry restoration in superstring perturbation theory

    International Nuclear Information System (INIS)

    Sen, Ashoke

    2015-01-01

    Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

  5. Left-right symmetric superstring supergravitation

    International Nuclear Information System (INIS)

    Burova, M.V.; Ter-Martirosyan, K.E.

    1988-01-01

    A left-right (L-R) symmetric model of four-dimensional supergravitation with a SO(10) gauge group obtained as the low-energy limit is superstring theory is considered. The spectrum of the gauge fields and their interactions are in agreement with the Weinberg-Salam theory. In addition, the model includes heavy W R ± and Z μ ' bosons. Beside the N g =3 generations of the 16-plets the SO(10) model includes the fragments of such generations which play the role of Higgs particles and also scalar chiral filds, the number of which exceeds by one the number of generations. As a result the neutrinos of each generation obtain a stable small Majorana mass. It is shown that the scalar field potential leads to spontaneous violation of the SU(2) R group and L-R symmetry and at low energies the standard Weinberg-Salam theory appears. However, reasonable values of X bosons masses M x and sun 2 Θ W (Θ W is the Weinberg angle) can be obtained in the model only in the case of high mass scale M R ∼10 10 -10 12 GeV of the right group SU(2) R violation

  6. Constraints on grand unified superstring theories

    International Nuclear Information System (INIS)

    Ellis, J.; Lopez, J.L.; Nanopoulos, D.V.; Houston Advanced Research Center

    1990-01-01

    We evaluate some constraints on the construction of grand unified superstring theories (GUSTs) using higher level Kac-Moody algebras on the world-sheet. In the most general formulation of the heterotic string in four dimensions, an analysis of the basic GUST model-building constraints, including a realistic hidden gauge group, reveals that there are no E 6 models and any SO(10) models can only exist at level-5. Also, any such SU(5) models can exist only for levels 4≤k≤19. These SO(10) and SU(5) models risk having many large, massless, phenomenologically troublesome representations. We also show that with a suitable hidden sector gauge group, it is possible to avoid free light fractionally charged particles, which are endemic to string derived models. We list all such groups and their representations for the flipped SU(5)xU(1) model. We conclude that a sufficiently binding hidden sector gauge group becomes a basic model-building constraint. (orig.)

  7. Green-Schwarz superstring on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, L. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof,Zum Großen Windkanal 6, 12489 Berlin (Germany); II. Institut für Theoretische Physik, Universität Hamburg,Luruper Chaussee 149, 22761 Hamburg (Germany); Bianchi, M.S. [Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Forini, V.; Leder, B.; Vescovi, E. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof,Zum Großen Windkanal 6, 12489 Berlin (Germany)

    2016-07-04

    We consider possible discretizations for a gauge-fixed Green-Schwarz action of Type IIB superstring. We use them for measuring the action, from which we extract the cusp anomalous dimension of planar N=4 SYM as derived from AdS/CFT, as well as the mass of the two AdS excitations transverse to the relevant null cusp classical string solution. We perform lattice simulations employing a Rational Hybrid Monte Carlo (RHMC) algorithm and two Wilson-like fermion discretizations, one of which preserves the global SO(6) symmetry of the model. We compare our results with the expected behavior at various values of g=((√λ)/(4π)). For both the observables, we find a good agreement for large g, which is the perturbative regime of the sigma-model. For smaller values of g, the expectation value of the action exhibits a deviation compatible with the presence of quadratic divergences. After their non-perturbative subtraction the continuum limit can be taken, and suggests a qualitative agreement with the non-perturbative expectation from AdS/CFT. Furthermore, we detect a phase in the fermion determinant, whose origin we explain, that for small g leads to a sign problem not treatable via standard reweigthing. The continuum extrapolations of the observables in the two different discretizations agree within errors, which is strongly suggesting that they lead to the same continuum limit. Part of the results discussed here were presented earlier in http://arxiv.org/abs/1601.04670.

  8. Superstring field theory equivalence: Ramond sector

    International Nuclear Information System (INIS)

    Kroyter, Michael

    2009-01-01

    We prove that the finite gauge transformation of the Ramond sector of the modified cubic superstring field theory is ill-defined due to collisions of picture changing operators. Despite this problem we study to what extent could a bijective classical correspondence between this theory and the (presumably consistent) non-polynomial theory exist. We find that the classical equivalence between these two theories can almost be extended to the Ramond sector: We construct mappings between the string fields (NS and Ramond, including Chan-Paton factors and the various GSO sectors) of the two theories that send solutions to solutions in a way that respects the linearized gauge symmetries in both sides and keeps the action of the solutions invariant. The perturbative spectrum around equivalent solutions is also isomorphic. The problem with the cubic theory implies that the correspondence of the linearized gauge symmetries cannot be extended to a correspondence of the finite gauge symmetries. Hence, our equivalence is only formal, since it relates a consistent theory to an inconsistent one. Nonetheless, we believe that the fact that the equivalence formally works suggests that a consistent modification of the cubic theory exists. We construct a theory that can be considered as a first step towards a consistent RNS cubic theory.

  9. Supersymmetry restoration in superstring perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ashoke [Harish-Chandra Research Institute,Chhatnag Road, Jhusi, Allahabad 211019 (India)

    2015-12-14

    Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

  10. Green-Schwarz superstring on the lattice

    International Nuclear Information System (INIS)

    Bianchi, L.; Bianchi, M.S.; Forini, V.; Leder, B.; Vescovi, E.

    2016-01-01

    We consider possible discretizations for a gauge-fixed Green-Schwarz action of Type IIB superstring. We use them for measuring the action, from which we extract the cusp anomalous dimension of planar N=4 SYM as derived from AdS/CFT, as well as the mass of the two AdS excitations transverse to the relevant null cusp classical string solution. We perform lattice simulations employing a Rational Hybrid Monte Carlo (RHMC) algorithm and two Wilson-like fermion discretizations, one of which preserves the global SO(6) symmetry of the model. We compare our results with the expected behavior at various values of g=((√λ)/(4π)). For both the observables, we find a good agreement for large g, which is the perturbative regime of the sigma-model. For smaller values of g, the expectation value of the action exhibits a deviation compatible with the presence of quadratic divergences. After their non-perturbative subtraction the continuum limit can be taken, and suggests a qualitative agreement with the non-perturbative expectation from AdS/CFT. Furthermore, we detect a phase in the fermion determinant, whose origin we explain, that for small g leads to a sign problem not treatable via standard reweigthing. The continuum extrapolations of the observables in the two different discretizations agree within errors, which is strongly suggesting that they lead to the same continuum limit. Part of the results discussed here were presented earlier in http://arxiv.org/abs/1601.04670.

  11. Introduction to covariant formulation of superstring (field) theory

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The author discusses covariant formulation of superstring theories based on BRS invariance. New formulation of superstring was constructed by Green and Schwarz in the light-cone gauge first and then a covariant action was discovered. The covariant action has some interesting geometrical interpretation, however, covariant quantizations are difficult to perform because of existence of local supersymmetries. Introducing extra variables into the action, a modified action has been proposed. However, it would be difficult to prescribe constraints to define a physical subspace, or to reproduce the correct physical spectrum. Hence the old formulation, i.e., the Neveu-Schwarz-Ramond (NSR) model for covariant quantization is used. The author begins by quantizing the NSR model in a covariant way using BRS charges. Then the author discusses the field theory of (free) superstring

  12. Type II Superstring Field Theory: Geometric Approach and Operadic Description

    CERN Document Server

    Jurco, Branislav

    2013-01-01

    We outline the construction of type II superstring field theory leading to a geometric and algebraic BV master equation, analogous to Zwiebach's construction for the bosonic string. The construction uses the small Hilbert space. Elementary vertices of the non-polynomial action are described with the help of a properly formulated minimal area problem. They give rise to an infinite tower of superstring field products defining a $\\mathcal{N}=1$ generalization of a loop homotopy Lie algebra, the genus zero part generalizing a homotopy Lie algebra. Finally, we give an operadic interpretation of the construction.

  13. The hexagon gauge anomaly in type 1 superstring theory

    International Nuclear Information System (INIS)

    Green, M.B.; Schwarz, J.H.

    1985-01-01

    Hexagon diagrams with external on-mass-shell Yang-Mills gauge particles are investigated in type I superstring theory. Both the annulus and the Moebuis-strip diagrams are shown to give anomalies, implying that spurious longitudinal modes cannot be consistently decoupled. However, the anomalies cancel when the two diagrams are added together if the gauge group is chosen to be SO(32). In carrying out the analysis, two different regulators are considered, but the same conclusions emerge in both cases. We point out where various terms in the low-energy effective action originate in superstring diagrams. (orig.)

  14. Infinite tension limit of the pure spinor superstring

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, Nathan [ICTP South American Institute for Fundamental Research,Instituto de Física Teórica, UNESP - Univ. Estadual Paulista,Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil)

    2014-03-04

    Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d=10 Yang-Mills amplitudes and the NS-NS sector of tree-level d=10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d=10 superspace version of the Cachazo-He-Yuan formulae for tree-level d=10 super-Yang-Mills and supergravity amplitudes.

  15. The monster sporadic group and a theory underlying superstring models

    International Nuclear Information System (INIS)

    Chapline, G.

    1996-09-01

    The pattern of duality symmetries acting on the states of compactified superstring models reinforces an earlier suggestion that the Monster sporadic group is a hidden symmetry for superstring models. This in turn points to a supersymmetric theory of self-dual and anti-self-dual K3 manifolds joined by Dirac strings and evolving in a 13 dimensional spacetime as the fundamental theory. In addition to the usual graviton and dilaton this theory contains matter-like degrees of freedom resembling the massless states of the heterotic string, thus providing a completely geometric interpretation for ordinary matter. 25 refs

  16. The S-matrix of superstring field theory

    International Nuclear Information System (INIS)

    Konopka, Sebastian

    2015-01-01

    We show that the classical S-matrix calculated from the recently proposed superstring field theories give the correct perturbative S-matrix. In the proof we exploit the fact that the vertices are obtained by a field redefinition in the large Hilbert space. The result extends to include the NS-NS subsector of type II superstring field theory and the recently found equations of motions for the Ramond fields. In addition, our proof implies that the S-matrix obtained from Berkovits’ WZW-like string field theory then agrees with the perturbative S-matrix to all orders.

  17. A new approach to strings and superstrings

    International Nuclear Information System (INIS)

    Sparano, G.

    1988-01-01

    The subject of this thesis is a new, more general, action principle for strings, superstrings, and extended objects in any number of dimensions. The origin and motivations for this approach can be found in the context of the study of the symmetries of string theories and, more specifically, are related to the application of K.S.K. (Kirillov, Souriau, Kostant) construction to strings. The main results we find are: (A) A classification of string theories analogous to the classification of relativistic point particles as massive, massless and tachionic with or without spin. Nambu-Goto string and Schild null string emerge as special cases of a more general classification of strings. (B) A new method to introduce spin in strings by using a Wess-Zumino term in the action. (C) Several results are obtained through the study of the configuration space which shows a rich topological structure: for the Nambu-Goto string in any number of dimensions it is found the existence of theta states analogous to the theta-vacua of nonabelian gauge theories. For the closed Schild Null string, in four dimensions, this analysis shows Z2 solitons and the possibility of quantizing the system so that the states are spinorial (have half odd integral spin) even though the Lagrangian consists only of bosonic variables. (D) Unlike Nambu-Goto string, the quantization of Schild Null string is consistent in any number of space-time dimensions. Besides these concrete results, the formalism we introduce will hopefully give also new insights in the problem of the hidden symmetries of the string

  18. AdS pure spinor superstring in constant backgrounds

    International Nuclear Information System (INIS)

    Chandia, Osvaldo; Bevilaqua, L. Ibiapina; Vallilo, Brenno Carlini

    2014-01-01

    In this paper we study the pure spinor formulation of the superstring in AdS_5×S"5 around point particle solutions of the classical equations of motion. As a particular example we quantize the pure spinor string in the BMN background

  19. Yukawa couplings in superstring compactification. [in quantum gravity theory

    Science.gov (United States)

    Strominger, A.

    1985-01-01

    A topological formula is given for the entire tree-level contribution to the low-energy effective action of a Calabi-Yau superstring compactification. The constraints on proton lifetime in the Calabi-Yau compactification are discussed in detail.

  20. The two loop superstring vacuum amplitude and canonical divisors

    International Nuclear Information System (INIS)

    Parkes, A.

    1989-01-01

    I use the prescription of placing the picture changing operators at the zeroes of some holomorphic one-form and calculate the two loop superstring vacuum amplitude in the language of theta functions. It vanishes pointwise on moduli space after the use of Fay's trisecant identity and generalised Riemann identities. I briefly discuss the higher genus case. (orig.)

  1. Green-Schwarz action and loop calculations for superstring

    International Nuclear Information System (INIS)

    Kallosh, R.; Morozov, A.

    1988-01-01

    The authors that Green-Schwartz explicitly 10d supersymmetric and 2d covariant approach without spin 1/2 and 3/2 fields on world sheet may appear suitable for calculations of loops in superstring theory. The way the cancellation of Polyakov anomaly is realized and the answer for 1-loop 4-point amplitudes are reproduced

  2. Heterotic superstring and curved, scale-invariant superspace

    International Nuclear Information System (INIS)

    Kuusk, P.K.

    1988-01-01

    It is shown that the modified heterotic superstring [R. E. Kallosh, JETP Lett. 43, 456 (1986); Phys. Lett. 176B, 50 (1986)] demands a scale-invariant superspace for its existence. Explicit expressions are given for the connection, the torsion, and the curvature of an extended scale-invariant superspace with 506 bosonic and 16 fermionic coordinates

  3. Vortices on the string and superstring world sheets

    International Nuclear Information System (INIS)

    Abrikosov, A.A.; Kogan, Ya.I.

    1989-01-01

    The world-sheet dynamics of the first quantized string propagating in non-simply connected space is considered. Presence of the vortices on the world sheet lead to Berezinsky-Kosterlitz-Thouless(BKT) phase transition. Bosonic and superstring cases are discussed. 20 refs.; 2 figs

  4. The Question of the Superstrate and Substrate in Nigerian Pidgin ...

    African Journals Online (AJOL)

    very extensively the grammatical systems of Nigerian languages. Based on the conviction that mainly grammatical operations describe the structure of a language, the paper concludes by proposing that either 1) the local languages be classified as the grammatical superstrate and lexifier substrate (that is, if degree

  5. Our universe as an attractor in a superstring model

    International Nuclear Information System (INIS)

    Maeda, Keiichi.

    1986-11-01

    One preferential scenario of the evolution of the universe is discussed in a superstring model. The universe can reach the present state as an attractor in the dynamical system. The kinetic terms of the ''axions'' play an important role so that our present universe is realized almost uniquely. (author)

  6. Ambitwistor superstring in the Green-Schwarz formulation

    Energy Technology Data Exchange (ETDEWEB)

    Chandia, Osvaldo [Universidad Adolfo Ibanez, Departamento de Ciencias, Facultad de Artes Liberales, Santiago (Chile); Vallilo, Brenno Carlini [Universidad Andres Bello, Departamento de Ciencias Fisicas, Santiago (Chile)

    2017-07-15

    In this paper we construct the ambitwistor superstring in the Green-Schwarz formulation. The model is obtained from the related pure spinor version. We show that the spectrum contains only ten-dimensional supergravity and that kappa symmetry in a curved background implies some of the standard constraints. (orig.)

  7. AdS pure spinor superstring in constant backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Chandia, Osvaldo [Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile); Bevilaqua, L. Ibiapina [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte,Caixa Postal 1524, 59072-970, Natal, RN (Brazil); Vallilo, Brenno Carlini [Facultad de Ciencias Exactas, Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile)

    2014-06-05

    In this paper we study the pure spinor formulation of the superstring in AdS{sub 5}×S{sup 5} around point particle solutions of the classical equations of motion. As a particular example we quantize the pure spinor string in the BMN background.

  8. Analytic solutions for marginal deformations in open superstring field theory

    International Nuclear Information System (INIS)

    Okawa, Y.

    2007-04-01

    We extend the calculable analytic approach to marginal deformations recently developed in open bosonic string field theory to open superstring field theory formulated by Berkovits. We construct analytic solutions to all orders in the deformation parameter when operator products made of the marginal operator and the associated superconformal primary field are regular. (orig.)

  9. Management of drug-induced hyperbilirubinaemia in early pregnancy

    African Journals Online (AJOL)

    perinatal outcomes because of the increased risks of preterm delivery and ... induced hepatotoxicity in early pregnancy. ... for threatened abortion since the 6th week. Her past and ... gene mutations, a disease complicated by unconjugated.

  10. Ethanol Induced Urine Acidification is Related with Early Acetaldehyde Concentration

    Directory of Open Access Journals (Sweden)

    Soon Kil Kwon

    2014-06-01

    Conclusion: In conclusion, urine acidification after ethanol ingestion is related with serum acetaldehyde concentration. Early elevation of acetaldhyde could induce urine acidification, but the urine pH was elevated after a few hours, that might make prolonged acidemia.

  11. Restudy of the open-superstring tree amplitudes by looking at their field-theoretical limits

    International Nuclear Information System (INIS)

    Hsu, R.; Yeung, W.B.; Yu, H.L.

    1987-01-01

    We carry out complete computations of some open- and closed-superstring tree amplitudes by using the bosonized covariant vertices. Some open-superstring amplitudes so obtained are shown to be different from those obtained in the light-cone gauge approach by some numerical factors. The low-energy limits of our five open-superstring amplitudes are then shown to match the five super Yang-Mills field amplitudes while the five light-cone gauge open-superstring amplitudes fail to do so

  12. Universality and clustering in 1 + 1 dimensional superstring-bit models

    International Nuclear Information System (INIS)

    Bergman, O.; Thorn, C.B.

    1996-01-01

    We construct a 1+1 dimensional superstring-bit model for D=3 Type IIB superstring. This low dimension model escapes the problem encountered in higher dimension models: (1) It possesses full Galilean supersymmetry; (2) For noninteracting Polymers of bits, the exactly soluble linear superpotential describing bit interactions is in a large universality class of superpotentials which includes ones bounded at spatial infinity; (3) The latter are used to construct a superstring-bit model with the clustering properties needed to define an S-matrix for closed polymers of superstring-bits

  13. On the construction of classical superstring field theories

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, Sebastian Johann Hermann

    2016-07-01

    This thesis describes the construction of classical superstring field theories based on the small Hilbert space. First we describe the traditional construction of perturbative superstring theory as an integral over the supermoduli space of type II world sheets. The geometry of supermoduli space dictates many algebraic properties of the string field theory action. In particular it allows for an algebraisation of the construction problem for classical superstring field theories in terms of homotopy algebras. Next, we solve the construction problem for open superstrings based on Witten's star product. The construction is recursive and involves a choice of homotopy operator for the zero mode of the η-ghost. It turns out that the solution can be extended to the Neveu-Schwarz subsectors of all superstring field theories. The recursive construction involves a hierarchy of string products at various picture deficits. The construction is not entirely natural, but it is argued that different choices give rise to solutions related by a field redefinition. Due to the presence of odd gluing parameters for Ramond states the extension to full superstring field theory is non-trivial. Instead, we construct gauge-invariant equations of motion for all superstring field theories. The realisation of spacetime supersymmetry in the open string sector is highly non-trivial and is described explicitly for the solution based on Witten's star product. After a field redefinition the non-polynomial equations of motion and the small Hilbert space constraint become polynomial. This polynomial system is shown to be supersymmetric. Quite interestingly, the supersymmetry algebra closes only up to gauge transformations. This indicates that only the physical phase space realizes N=1 supersymmetry. Apart from the algebraic constraints dictated by the geometry of supermoduli space the equations of motion or action should reproduce the traditional string S-matrix. The S-matrix of a field

  14. Exploring the lambda model of the hybrid superstring

    Energy Technology Data Exchange (ETDEWEB)

    Schmidtt, David M. [Instituto de Física Teórica IFT/UNESP,Rua Dr. Bento Teobaldo Ferraz 271, Bloco II, CEP 01140-070, São Paulo-SP (Brazil)

    2016-10-26

    The purpose of this contribution is to initiate the study of integrable deformations for different superstring theory formalisms that manifest the property of (classical) integrability. In this paper we choose the hybrid formalism of the superstring in the background AdS{sub 2}×S{sup 2} and explore in detail the most immediate consequences of its λ-deformation. The resulting action functional corresponds to the λ-model of the matter part of the fairly more sophisticated pure spinor formalism, which is also known to be classical integrable. In particular, the deformation preserves the integrability and the one-loop conformal invariance of its parent theory, hence being a marginal deformation.

  15. Worldsheet dilatation operator for the AdS superstring

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, Israel [Departamento de Física, Universidad Técnica Federico Santa María,Casilla 110-V, Valparaíso (Chile); Institut für Mathematik und Institut für Physik, Humboldt-Universität zu Berlin,IRIS Haus, Zum Großen Windkanal 6, 12489 Berlin (Germany); Vallilo, Brenno Carlini [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago (Chile)

    2016-05-23

    In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the AdS{sub 5}×S{sup 5} superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.

  16. Calculation and modular properties of multiloop superstring amplitudes

    International Nuclear Information System (INIS)

    Danilov, G. S.

    2013-01-01

    Multiloop superstring amplitudes are calculated within an extensively used gauge where the two-dimensional gravitino field carries Grassmann moduli. In general, the amplitudes possess, instead of modular symmetry, symmetry with respect to modular transformation supplemented with appropriate transformations of two-dimensional local supersymmetry. If the number of loops is larger than three, the integrationmeasures are notmodular forms, while the expression for the amplitude contains integrals along the boundary of the fundamental region of the modular group.

  17. Massive supermultiplets in four-dimensional superstring theory

    International Nuclear Information System (INIS)

    Feng Wanzhe; Lüst, Dieter; Schlotterer, Oliver

    2012-01-01

    We extend the discussion of Feng et al. (2011) on massive Regge excitations on the first mass level of four-dimensional superstring theory. For the lightest massive modes of the open string sector, universal supermultiplets common to all four-dimensional compactifications with N=1,2 and N=4 spacetime supersymmetry are constructed respectively - both their vertex operators and their supersymmetry variations. Massive spinor helicity methods shed light on the interplay between individual polarization states.

  18. BRST cohomology of the superstring at arbitrary ghost number

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Myers, R.C.; Martin, S.P.

    1989-01-01

    We investigate the cohomology of the BRST operator of the NSR superstring. No restriction is placed on the ghost number of the states. It is shown that every cohomology class can be written as a picture changed version of one of the known cohomology classes at a fixed ghost number. A generalization of this result is also found for the cohomology in the large algebra of a new bosonization of the superconformal ghosts. (orig.)

  19. Spring School on Superstring Theory and Related Topics

    CERN Document Server

    2017-01-01

    ICTP's annual Spring School on Superstring Theory and Related Topics provides pedagogical treatment of these subjects through lectures by some of the world's top string theorists. The activity is intended for theoretical physicists or mathematicians with knowledge of quantum field theory, general relativity and string theory. It is organized in collaboration with the Asia Pacific Center for Theoretical Physics (APCTP) and the Italian Institute for Nuclear Physics (INFN).

  20. Superstring-inspired SO(10) GUT model with intermediate scale

    Science.gov (United States)

    Sasaki, Ken

    1987-12-01

    A new mechanism is proposed for the mixing of Weinberg-Salam Higgs fields in superstring-inspired SO(10) models with no SO(10) singlet fields. The higher-dimensional terms in the superpotential can generate both Higgs field mixing and a small mass for the physical neutrino. I would like to thank Professor C. Iso for hospitality extended to me at the Tokyo Institute of Technology.

  1. Double covering of diffeomorphisms for superstrings in generic curved space

    International Nuclear Information System (INIS)

    Ne'eman, Y.; Sijacki, D.

    1986-01-01

    The embedding of the superstring in a generic curved space involves the use of world-spinors behaving according to the (infinite) unitary representations of SL-bar(10,R), the double-covering of the linear group on R 10 . A supersymmetric extrension is provided by the embedding of GL-bar(10,R) in the supergroup GQ-bar(10,R) whose flat limit reproduces Poincare supersymmetry

  2. Superstrings and preons: a new approach to unification

    International Nuclear Information System (INIS)

    Pati, J.C.

    1987-01-01

    The superstring theories generate the new prospect that one may finally have a consistent unified quantum theory of all forces including gravity. In spite of many attractive features, however, these theories appear so far to be beset with serious difficulties in describing the real world, like the problem of the fermion mass hierarchy and fermion mixings. For these reasons, it has been suggested that the advantages of the superstring theories as regards (a) uniqueness, (b) parameterlessness and (c) good quantum gravity may be retained and yet the difficulties may be circumvented if the fundamental four dimensional fields are identified with preons rather than with quarks and leptons. Such an identification would also enhance the prospect of an understanding of the fermion mass hierarchy because of new dynamics and new symmetries, which naturally arise within preonic theories, especially those with supersymmetry. Some new developments in preonic ideas are presented which may help remove certain dilemmas of preon dynamics. The so-called 'maximal' preon models are developed and it is indicated how they may have their origins from the superstring theories. A few crucial tests of these ideas are listed which can be verified by experiments at LEP, SLC and SSC and also by searches for certain rare processes. 29 refs.; 1 table

  3. Strategic Capacity Rationing to Induce Early Purchases

    OpenAIRE

    Qian Liu; Garrett J. van Ryzin

    2008-01-01

    Dynamic pricing offers the potential to increase revenues. At the same time, it creates an incentive for customers to strategize over the timing of their purchases. A firm should ideally account for this behavior when making its pricing and stocking decisions. In particular, we investigate whether it is optimal for a firm to create rationing risk by deliberately understocking products. Then, the resulting threat of shortages creates an incentive for customers to purchase early at higher price...

  4. Radiation induced early maturing mutants in barley

    International Nuclear Information System (INIS)

    Kumar, R.; Chauhan, S.V.S.; Sharma, R.P.

    1978-01-01

    In M 2 generation, two early maturing plants were screened from a single spike progeny of a plant obtained from 20 kR of gamma-ray irradiation of a six-rowed barley (Hordeum vulgare L. var. Jyoti). Their true breeding nature was confirmed in M 3 generation. These mutants flower and mature 38 and 22 days earlier than those of control. (auth.)

  5. Early haemorrhage control and management of trauma-induced coagulopathy

    DEFF Research Database (Denmark)

    Stensballe, Jakob; Henriksen, Hanne H; Johansson, Pär I

    2017-01-01

    of trauma resuscitation using a ratio-driven strategy aiming at 1:1:1 of red blood cells, plasma and platelets while applying goal-directed therapy early and repeatedly to control trauma-induced coagulopathy. SUMMARY: Trauma resuscitation should focus on early goal-directed therapy with use of viscoelastic...... haemostatic assays while initially applying a ratio 1:1:1 driven transfusion therapy (with red blood cells, plasma and platelets) in order to sustain normal haemostasis and control further bleeding....

  6. Pure spinor partition function and the massive superstring spectrum

    International Nuclear Information System (INIS)

    Aisaka, Yuri; Arroyo, E. Aldo; Berkovits, Nathan; Nekrasov, Nikita

    2008-01-01

    We explicitly compute up to the fifth mass-level the partition function of ten-dimensional pure spinor worldsheet variables including the spin dependence. After adding the contribution from the (x μ , θ α , p α ) matter variables, we reproduce the massive superstring spectrum. Even though pure spinor variables are bosonic, the pure spinor partition function contains fermionic states which first appear at the second mass-level. These fermionic states come from functions which are not globally defined in pure spinor space, and are related to the b ghost in the pure spinor formalism. This result clarifies the proper definition of the Hilbert space for pure spinor variables.

  7. Cohomology in the Pure Spinor Formalism for the Superstring

    International Nuclear Information System (INIS)

    Berkovits, Nathan

    2000-01-01

    A manifestly super-Poincare covariant formalism for the superstring has recently been constructed using a pure spinor variable. Unlike the covariant Green-Schwarz formalism, this new formalism is easily quantized with a BRST operator and tree-level scattering amplitudes have been evaluated in a manifestly covariant manner. In this paper, the cohomology of the BRST operator in the pure spinor formalism is shown to give the usual light-cone Green-Schwarz spectrum. Although the BRST operator does not directly involve the Virasoro constraint, this constraint emerges after expressing the pure spinor variable in terms of SO(8) variables. (author)

  8. Calculation and modular properties of multi-loop superstring amplitudes

    International Nuclear Information System (INIS)

    Danilov, G S

    2012-01-01

    Multi-loop superstring amplitude is calculated in the conventional gauge where Grassmann moduli are carried by the 2D gravitino field. Generally, instead of the modular symmetry, the amplitudes hold the symmetry under modular transformations added by relevant transformations of the 2D local supersymmetry. If a number of loops are larger than 3, the integration measures are not modular forms. In this case the expression for the amplitude contains an integral over the bound of the fundamental region of the modular group. (paper)

  9. Low-energy effective action for the superstring

    International Nuclear Information System (INIS)

    Burgess, C.P.; Font, A.; Quevedo, F.

    1986-01-01

    We construct the low-energy D=4, N=1 supergravity that arises in superstring theories for an arbitrary number of generations. The coupling of all massless modes that carry low-energy gauge quantum numbers are calculated by truncating the heavy Kaluza-Klein modes of the ten-dimensional effective field theory. The resulting action is compared to the most general effective action compatible with the symmetries of the underlying ten-dimensional field (and string) theories. This comparison indicates which features of the truncation correctly approximate the exact low-energy action. (orig.)

  10. General dimensional reduction of ten-dimensional supergravity and superstring

    International Nuclear Information System (INIS)

    Ferrara, S.; Porrati, M.

    1986-01-01

    Dimensional reductions of supergravity theories are shown to yield to specific glasses of four-dimensional no-scale models with N=4, 2 or 1 residual supersymmetry. N=1 ''maximal'' supergravity lagrangian, corresponding to the ''untwisted'' sector of orbifold compactification of superstrings, contains nine families and has a no-scale structure based on the Kaehler manifold [SU(3, 3+3n)/SU(3)xSU(3+3n)]x[SU(1, 1)/U(1)]. The quantum consistency of the resulting theories give information on the non Kaluza-Klein (string) ''twisted'' sector. (orig.)

  11. Localization of effective actions in open superstring field theory

    Science.gov (United States)

    Maccaferri, Carlo; Merlano, Alberto

    2018-03-01

    We consider the construction of the algebraic part of D-branes tree-level effective action from Berkovits open superstring field theory. Applying this construction to the quartic potential of massless fields carrying a specific worldsheet charge, we show that the full contribution to the potential localizes at the boundary of moduli space, reducing to elementary two-point functions. As examples of this general mechanism, we show how the Yang-Mills quartic potential and the instanton effective action of a Dp/D( p - 4) system are reproduced.

  12. R parity in standard-like superstring models

    International Nuclear Information System (INIS)

    Halyo, Edi.

    1994-01-01

    We investigate the R symmetries of standard-like superstring models. At the level of the cubic superpotential there are three global U(1) R symmetries. These are broken explicitly by N > 3 terms in the superpotential and spontaneously by scalar Vacuum Expectation values necessary to preserve supersymmetry at Mp. A Z 2 discrete symmetry remains but is equivalent to fermion number modulo 2. These models possess an effective R parity which arises from the interplay between the gauged U(1) B-L and U(1) r j+3 . (author). 14 refs

  13. On the viability of rank-six superstring models

    International Nuclear Information System (INIS)

    Campbell, B.A.; Olive, K.A.; Reiss, D.B.

    1988-01-01

    We consider the possibility of breaking a rank-six superstring model to the rank-four standard model. In particular, we point out the difficulties in generating two vacuum expectation values for the two standard model singlets contained in the 27 of E 6 . Although one expectation value is compatible with low energy phenomenology, a vev for ν c is problematic because of the absence of large neutrino masses and/or flavor changing neutral currents. We show that even simple models containing extra fields from incomplete multiplets or E 6 singlets do not resolve these problems. (orig.)

  14. A three-generation superstring model. Pt. 1

    International Nuclear Information System (INIS)

    Greene, B.R.; Kirklin, K.H.; Miron, P.J.; Ross, G.G.

    1986-01-01

    We present the preliminary analysis of a three-generation heterotic superstring-inspired model. A detailed mathematical description of the manifold of compactification is given, along with a determination of its Hodge numbers and of the associated light supermultiplet structure. For a particular choice of vacuum moduli we derive this manifold's symmetry and groups, and determine their action on the massless fields in the theory. These transformation properties shall be shown, in a companion paper, to give rise to a model with interesting phenomenological properties. (orig.)

  15. Superstring interactions in a pp-wave background II

    International Nuclear Information System (INIS)

    Spradlin, Marcus; Volovich, Anastasia

    2003-01-01

    In type-IIB light-cone superstring field theory, the cubic interaction has two pieces: a delta-functional overlap and an operator inserted at the interaction point. In this paper we extend our earlier work by computing the matrix elements of this operator in the oscillator basis of pp-wave string theory for all μ p +α '. By evaluating these matrix elements for large μ p +α ', we check a recent conjecture relating matrix elements of the light-cone string field theory hamiltonian (with prefactor) to certain three-point functions of BMN operators in the gauge theory. We also make several predictions for gauge theory. (author)

  16. All the fundamental massless bosonic fields in superstring theory

    International Nuclear Information System (INIS)

    Manoukian, E.B.

    2012-01-01

    A systematic analysis of all the massless bosonic fields in superstring theory is carried out. Emphasis is put on the derivation of their propagators, their polarization aspects and the investigation of their underlying constraints as well as their number of degrees of freedom. The treatment is given in the presence of external sources, in the celebrated Coulomb gauge, ensuring the positivity of the formalism - a result which is also established in the process. The challenge here is the investigation involved in the self-dual fourth rank anti-symmetric tensor field. No constraints are imposed on the external sources so that their components may be varied independently, thus the complete expressions of the propagators may be obtained. As emphasized in our earlier work, the latter condition is an important one in dynamical theories with constraints giving rise to modifications as Faddeev-Popov factors. The analysis is carried out in 10 dimensions, not only because of the consistency requirement by the superstrings, but also in order to take into account of the self-duality character of the fourth rank anti-symmetric tensor field as spelled out in the paper. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Group-geometric methods in supergravity and superstring theories

    International Nuclear Information System (INIS)

    Castellani, L.

    1992-01-01

    The purpose of this paper is to give a brief and pedagogical account of the group-geometric approach to (super)gravity and superstring theories. The authors summarize the main ideas and apply them to selected examples. Group geometry provides a natural and unified formulation of gravity and gauge theories. The invariance of both are interpreted as diffeomorphisms on a suitable group manifold. This geometrical framework has a fruitful output, in that it provides a systematic algorithm for the gauging of Lie algebras and the construction of (super)gravity or (super)string Lagrangians. The basic idea is to associate fundamental fields to the group generators. This is done by considering first a basis of tangent vectors on the group manifold. These vectors close on the same algebra as the abstract group generators. The dual basis, i.e. the vielbeins (cotangent basis of one-forms) is then identified with the set of fundamental fields. Thus, for example, the vielbein V a and the spin connection ω ab of ordinary Einstein-Cartan gravity are seen as the duals of the tangent vectors corresponding to translations and Lorentz rotations, respectively

  18. Supersymmetry: Kaluza-Klein theory, anomalies, and superstrings

    International Nuclear Information System (INIS)

    Aref'eva, I.Y.; Volovich, I.V.

    1985-01-01

    Progress in the search for a unified theory of elementary particles is reviewed. The supersymmetrical Kaluza-Klein theories are described: 11-, 10-, and 6-dimensional models of supergravity. The methods of spontaneous compactification, with whose help the four-dimensional theories are obtained, are described. The properties of the massless sector: zero modes in the Kaluza-Klein theories: and the question of the stability of vacuum solutions are discussed. An important criterion for the selection of a self-consistent theory is the absence of anomalies. The basic formulas for multidimensional chiral and gravitational anomalies are presented. The mechanism of the cancellation of the anomaly for Green and Schwarz's 10-dimensional effective field theory of superstrings with the gauge groups SO(32) and E 8 x E 8 is described. The basic concepts and the results of the theory of superstrings are presented. This theory has no divergences and is at the present time a very attractive candidate for a unified theory of elementary particles

  19. Green-Schwarz superstring: Beltrami parametrization and world-sheet supersymmetric generalization

    International Nuclear Information System (INIS)

    Binetruy, P.; Girardi, G.; Grimm, R.

    1989-06-01

    We study a generalization of the superstring theory in which both world-sheet and space-time supersymmetries are explicit. This hybrid superstring interpolates between the Green-Schwarz and the Ramond-Neveu-Schwarz formulations. We show that the Beltrami parametrization of the world-sheet provides a natural setting for the description of K-transformations already in the Green-Schwarz string. We construct the hybrid superstring action using the (1,1) supersymmetric version of the Beltrami parametrization. We discuss the generalization of k-transformations

  20. Anomaly-free gauges in superstring theory and double supersymmetric sigma-model

    International Nuclear Information System (INIS)

    Demichev, A.P.; Iofa, M.Z.

    1991-01-01

    Superharmonic gauge which is a nontrivial analog of the harmonic gauge in bosonic string theory is constructed for the fermionic superstrings. In contrast to the conformal gauge, the harmonic gauge in bosonic string and superharmonic gauge in superstring theory are shown to be free from previously discovered BRST anomaly (in critical dimension) in higher orders of string perturbation theory and thus provide the setup for consistent quantization of (super)string theory. Superharmonic gauge appears to be closely connected with the supersymmetric σ-model with the target space being also a supermanifold. 28 refs

  1. String field theory. Algebraic structure, deformation properties and superstrings

    International Nuclear Information System (INIS)

    Muenster, Korbinian

    2013-01-01

    This thesis discusses several aspects of string field theory. The first issue is bosonic open-closed string field theory and its associated algebraic structure - the quantum open-closed homotopy algebra. We describe the quantum open-closed homotopy algebra in the framework of homotopy involutive Lie bialgebras, as a morphism from the loop homotopy Lie algebra of closed string to the involutive Lie bialgebra on the Hochschild complex of open strings. The formulation of the classical/quantum open-closed homotopy algebra in terms of a morphism from the closed string algebra to the open string Hochschild complex reveals deformation properties of closed strings on open string field theory. In particular, we show that inequivalent classical open string field theories are parametrized by closed string backgrounds up to gauge transformations. At the quantum level the correspondence is obstructed, but for other realizations such as the topological string, a non-trivial correspondence persists. Furthermore, we proof the decomposition theorem for the loop homotopy Lie algebra of closed string field theory, which implies uniqueness of closed string field theory on a fixed conformal background. Second, the construction of string field theory can be rephrased in terms of operads. In particular, we show that the formulation of string field theory splits into two parts: The first part is based solely on the moduli space of world sheets and ensures that the perturbative string amplitudes are recovered via Feynman rules. The second part requires a choice of background and determines the real string field theory vertices. Each of these parts can be described equivalently as a morphism between appropriate cyclic and modular operads, at the classical and quantum level respectively. The algebraic structure of string field theory is then encoded in the composition of these two morphisms. Finally, we outline the construction of type II superstring field theory. Specific features of the

  2. The relation between operator and path integral covariant quantizations of the Green-Schwarz superstring

    International Nuclear Information System (INIS)

    Nissimov, E.; Pacheva, S.; Solomon, S.

    1989-02-01

    By further study of the geometry of the harmonic superspace constraints, we make explicit the relation between the operator and path integral approaches to the manifestly covariant harmonic superstring. In particular we find the correct complete set of functionally independent gauge symmetries for the auxiliary variables and identify the ones corresponding to the harmonic superfield postulate in the operator formalism. Then, we deduce in a systematic way the lagrangian path integral from the well defined covariant hamiltonian formulation of the GS superstring. (authors)

  3. [Clinical study of induced abortion of early-early pregnancy: an analysis of 10, 404 cases].

    Science.gov (United States)

    Kang, Jian; Wang, Xue-fen; Zhang, Li; Liu, Jian-hua

    2012-01-03

    To evaluate the advantages and disadvantages of early-early pregnancy induced abortion (EPIA). A total of 10 404 cases of EPIA performed at our hospital from January 1993 to December 2003 were retrospectively analyzed and compared with 9434 cases of common induced abortion (CIA). The amount of hemorrhage and operative duration, degree of pain, rate of induced-abortion syndrome, rate of incomplete abortion, menstrual changes and post-operative onset of Asherman's syndrome were observed and compared between 2 groups. The average age, ratio of parous cases, ratio of the cases of first-pregnancy induced abortion were not different between 2 groups (P > 0.05). The amount of hemorrhage bleeding ((4.9 ± 3.2) ml), operative duration ((90.3 ± 12.4) s), degree of pain, rate of induced-abortion syndrome, menstrual changes and the rate of Asherman's syndrome in the EPIA group were all significantly less than those in the CIA group (P abortion (0.44%) in the EPIA group was significantly higher than that (0.21%) in the CIA group (P abortion stays high.

  4. D-brane. Superstrings and new perspective of our world

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Koji [RIKEN, Saitama, Wako (Japan). Mathematical Physics Lab.

    2012-07-01

    Superstring theory is a promising theory which can potentially unify all the forces and the matters in particle physics. A new multi-dimensional object which is called ''D-brane'' was found. It drastically changed our perspective of a unified world. We may live on membrane-like hypersurfaces in higher dimensions (''braneworld scenario''), or we can create blackholes at particle accelerators, or the dynamics of quarks is shown to be equivalent to the higher dimensional gravity theory. All these scenarios are explained in this book with plain words but with little use of equations and with many figures. The book starts with a summary of long-standing problems in elementary particle physics and explains the D-branes and many applications of them. It ends with future roads for a unified ultimate theory of our world. (orig.)

  5. Super-Chern-Simons Theory as Superstring Theory

    CERN Document Server

    Grassi, P A

    2004-01-01

    Superstrings and topological strings with supermanifolds as target space play a central role in the recent developments in string theory. Nevertheless the rules for higher-genus computations are still unclear or guessed in analogy with bosonic and fermionic strings. Here we present a common geometrical setting to develop systematically the prescription for amplitude computations. The geometrical origin of these difficulties is the theory of integration of superforms. We provide a translation between the theory of supermanifolds and topological strings with supertarget space. We show how in this formulation one can naturally construct picture changing operators to be inserted in the correlation functions to soak up the zero modes of commuting ghost and we derive the amplitude prescriptions from the coupling with an extended topological gravity on the worldsheet. As an application we consider a simple model on R^(3|2) leading to super-Chern-Simons theory.

  6. Threshold corrections and gauge symmetry in twisted superstring models

    International Nuclear Information System (INIS)

    Pierce, D.M.

    1994-01-01

    Threshold corrections to the running of gauge couplings are calculated for superstring models with free complex world sheet fermions. For two N=1 SU(2)xU(1) 5 models, the threshold corrections lead to a small increase in the unification scale. Examples are given to illustrate how a given particle spectrum can be described by models with different boundary conditions on the internal fermions. We also discuss how complex twisted fermions can enhance the symmetry group of an N=4, SU(3)xU(1)xU(1) model to the gauge group SU(3)xSU(2)xU(1). It is then shown how a mixing angle analogous to the Weinberg angle depends on the boundary conditions of the internal fermions

  7. Scaling properties of cosmic (super)string networks

    International Nuclear Information System (INIS)

    Martins, C J A P

    2014-01-01

    I use a combination of state-of-the-art numerical simulations and analytic modelling to discuss the scaling properties of cosmic defect networks, including superstrings. Particular attention is given to the role of extra degrees of freedom in the evolution of these networks. Compared to the 'plain vanilla' case of Goto-Nambu strings, three such extensions play important but distinct roles in the network dynamics: the presence of charges/currents on the string worldsheet, the existence of junctions, and the possibility of a hierarchy of string tensions. I also comment on insights gained from studying simpler defect networks, including Goto-Nambu strings themselves, domain walls and semilocal strings

  8. Yukawa couplings in Superstring derived Standard-like models

    International Nuclear Information System (INIS)

    Faraggi, A.E.

    1991-01-01

    I discuss Yukawa couplings in Standard-like models which are derived from Superstring in the free fermionic formulation. I introduce new notation for the construction of these models. I show how choice of boundary conditions selects a trilevel Yukawa coupling either for +2/3 charged quark or for -1/3 charged quark. I prove this selection rule. I make the conjecture that in this class of standard-like models a possible connection may exist between the requirements of F and D flatness at the string level and the heaviness of the top quark relative to lighter quarks and leptons. I discuss how the choice of boundary conditions determines the non vanishing mass terms for quartic order terms. I discuss the implication on the mass of the top quark. (author)

  9. Field theory of interacting open superstrings of fermionic ghost representation

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Medvedev, P.V.

    1987-01-01

    Field theory of interacting open superstring in fermionic ghost representation based on anticommuting and commuting ghosts corresponding respectively to world sheet bosonic x μ and fermionic φ μ coordinates is presented. The author have to revise once more the field theory of the free Ramond (R) string and starting from general algebraic point of view they obtain that the number of degrees of freedom in the R and NS (Neveu-Schwartz) sectors equalise themselves permitting to construct a supersymmetric operator. It is proposed to solve a specific equation guaranteeing superinvariance in order to find the R-R-NS and NS-R-R vertices in the term of the NS-NS-NS vertex

  10. Supersymmetry breaking and dynamical determination of superstring parameters

    International Nuclear Information System (INIS)

    Casas, J.A.; Munoz, C.; Ross, G.G.

    1991-01-01

    The characteristics of the effective potentials coming from phenomenologically promising compactified superstring theories are examined, paying special attention to the supersymmetry breaking issue. We briefly review the status and some of the recent work on the subject and present a mechanism for generating the large gauge hierarchy by gaugino condensation effect in the case that the hidden sector possesses more than one condensate. Explicit examples based on orbifold compactification in which this is realized are also given. Minimization of the effective potential not only determines the gauge hierarchy but also fixes other important parameters of the theory, in particular the gauge coupling constant at the unification point and the expectation values of the moduli which give the size and shape of the compactified space. These get raesonable values which may, in turn, lead to a determination of the family mass hierarchy. (orig.)

  11. Problems for superstring models with vacuum expectation values for conjugate sneutrinos

    International Nuclear Information System (INIS)

    Campbell, B.; Ellis, J.; Gaillard, M.K.; Nanopoulos, D.V.; Olive, K.A.

    1986-01-01

    Superstring models compactified on Calabi-Yau manifolds contain two new neutral scalars in each 27 generation of chiral supermultiplets. We consider implications of a vacuum expectation value for one of the neutral scalars, the conjugates neutrino ν tilde L c : L c vertical stroke0>=y. Apart from a coupling which generates a Dirac neutrino mass and which must be small [ -9 )], its only superpotential interaction is with D L d L , so there wold be D-d mixing if y≠0. The fact that m d is not much less than m e or m u then tells us that y ν , arises if y≠0, and the D-d mixing would then induce the decay K→π+a ν at an unacceptable rate. Regardless of the gauge group rank, we show that the combined constraints on D-d mixing, and on the flavour-changing neutral currents it would induce, are sufficient to rule out D L d L c ν L c superpotential coupling large enough to produce L c vertical stroke0>≠0. These problems are avoided in models with a rank-5 gauge group and L c vertical stroke0>< or approx.40 KeV. (orig.)

  12. Detection of early caries by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-07-01

    To improve sensitivity of dental caries detection by laser-induced breakdown spectroscopy (LIBS) analysis, it is proposed to utilize emission peaks in the ultraviolet. We newly focused on zinc whose emission peaks exist in ultraviolet because zinc exists at high concentration in the outer layer of enamel. It was shown that by using ratios between heights of an emission peak of Zn and that of Ca, the detection sensitivity and stability are largely improved. It was also shown that early caries are differentiated from healthy part by properly setting a threshold in the detected ratios. The proposed caries detection system can be applied to dental laser systems such as ones based on Er:YAG-lasers. When ablating early caries part by laser light, the system notices the dentist that the ablation of caries part is finished. We also show the intensity of emission peaks of zinc decreased with ablation with Er:YAG laser light.

  13. Early embryonic androgen exposure induces transgenerational epigenetic and metabolic changes.

    Science.gov (United States)

    Xu, Ning; Chua, Angela K; Jiang, Hong; Liu, Ning-Ai; Goodarzi, Mark O

    2014-08-01

    Androgen excess is a central feature of polycystic ovary syndrome (PCOS), which affects 6% to 10% of young women. Mammals exposed to elevated androgens in utero develop PCOS-like phenotypes in adulthood, suggesting fetal origins of PCOS. We hypothesize that excess androgen exposure during early embryonic development may disturb the epigenome and disrupt metabolism in exposed and unexposed subsequent generations. Zebrafish were used to study the underlying mechanism of fetal origins. Embryos were exposed to androgens (testosterone and dihydrotestosterone) early at 26 to 56 hours post fertilization or late at 21 to 28 days post fertilization. Exposed zebrafish (F0) were grown to adults and crossed to generate unexposed offspring (F1). For both generations, global DNA methylation levels were examined in ovaries using a luminometric methylation assay, and fasting and postprandial blood glucose levels were measured. We found that early but not late androgen exposure induced changes in global methylation and glucose homeostasis in both generations. In general, F0 adult zebrafish exhibited altered global methylation levels in the ovary; F1 zebrafish had global hypomethylation. Fasting blood glucose levels were decreased in F0 but increased in F1; postprandial glucose levels were elevated in both F0 and F1. This androgenized zebrafish study suggests that transient excess androgen exposure during early development can result in transgenerational alterations in the ovarian epigenome and glucose homeostasis. Current data cannot establish a causal relationship between epigenetic changes and altered glucose homeostasis. Whether transgenerational epigenetic alteration induced by prenatal androgen exposure plays a role in the development of PCOS in humans deserves study.

  14. Early-life family structure and microbially induced cancer risk.

    Science.gov (United States)

    Blaser, Martin J; Nomura, Abraham; Lee, James; Stemmerman, Grant N; Perez-Perez, Guillermo I

    2007-01-01

    Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men. We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative), belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0) among those in a sibship of seven or more individuals than in a sibship of between one and three persons. These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

  15. The open superstring 6-point amplitude with manifest symmetries

    International Nuclear Information System (INIS)

    Barreiro, Luiz Antonio; Medina, Ricardo; Stieberger, Stephan

    2011-01-01

    Full text: The general tree level amplitude for massless bosons states of open superstrings has been known for a long time ago. It is clear how to obtain this general formula using vertex operators in the Ramond-Neveu-Schwarz formalism. From the beginning of the eighties the explicit expression for this formula has been known in the case of 3 and 4-point amplitudes. In that decade an attempt (with partial success) was done, by Kitazawa, to obtain the corresponding 5-point amplitude. Only in 2002 a complete and correct expression for this amplitude was obtained. Its low energy expansion was compared to the corresponding one from the low energy effective Lagrangian of the open superstring, finding a perfect match. A few years later, in 2005, it was realized that the 5-point formula could be written in a very much compact form, as a sum of two terms: each of them consisting of a momentum factor and a kinematic expression. This constituted a generalization of the 4-point amplitude case, which had been known to be cast in only one momentum factor multiplied by one kinematic expression. For this simplification to happen, known symmetries of the (tree level) scattering amplitudes were implemented in a manifest form. These symmetries are (on-shell) gauge symmetry, cyclic symmetry and twisting symmetry (or world sheet parity). In the recent years it has been realized that the N-point amplitude can be written as a sum of (N - 3)! terms (where N > 3). This result not only agrees with the 3, 4 and 5-point results, but also with the 6-point result which had been obtained by 2005, written as a sum of six terms. The expression that up to now has been obtained for the 6-point amplitude is quite complicated and, besides knowing that it consists of six terms, is not very illuminating. In this work we report on the recent result of writing the 6-point amplitude with gauge, cyclic and twisting symmetries manifest. Not only because of the manifest symmetries this result is important

  16. Effect of Two Different Superstrate Layers On Bismuth Titanate (BiT) Array Antennas

    Science.gov (United States)

    Wee, F. H.; Malek, F.; Al-Amani, A. U.; Ghani, Farid

    2014-01-01

    The microwave industry has shown increasing interest in electronic ceramic material (ECM) due to its advantages, such as light weight, low cost, low loss, and high dielectric strength. In this paper, simple antennas covered by superstrate layers for 2.30 GHz to 2.50 GHz are proposed. The antennas are compact and have the capability of producing high performance in terms of gain, directivity, and radiation efficiency. Bismuth titanate with high dielectric constant of 21, was utilized as the ECM, while the superstrate layers chosen included a split ring resonator and dielectric material. The superstrate layers were designed for some improvement in the performance of directivity, gain, and return loss. The proposed antennas were simulated and fabricated. The results obtained were small antennas that possess high gain and high directivity with 360°, omni-directional signal transmission that resonant types of conventional dipole antenna cannot achieve. The gain of the antenna with the superstrate layer was enhanced by about 1 dBi over the antenna without a superstrate layer at 2.40 GHz.

  17. Noncommutative D-branes from covariant AdS superstring

    International Nuclear Information System (INIS)

    Sakaguchi, Makoto; Yoshida, Kentaroh

    2008-01-01

    We study noncommutative (NC) D-branes on AdS 5 xS 5 from κ-invariance of covariant Green-Schwarz action of an open string with a non-trivial world-volume flux. Finding boundary conditions to ensure the κ-invariance, we can see possible configurations of the NC D-branes. With this method 1/4 BPS NC D-branes are discussed. The resulting NC Dp-branes are 1/4 BPS at arbitrary position other than the p=1 case. The exceptional D-string is 1/2 BPS at the origin and 1/4 BPS outside the origin. Those are reduced to possible 1/4 BPS or 1/2 BPS AdS D-branes in the commutative limit. The same analysis is applied to an open superstring in a pp-wave and leads to 1/4 BPS configurations of NC D-branes. These D-branes are consistently obtained from AdS D-branes via the Penrose limit

  18. Double scaling limits and twisted non-critical superstrings

    International Nuclear Information System (INIS)

    Bertoldi, Gaetano

    2006-01-01

    We consider double-scaling limits of multicut solutions of certain one matrix models that are related to Calabi-Yau singularities of type A and the respective topological B model via the Dijkgraaf-Vafa correspondence. These double-scaling limits naturally lead to a bosonic string with c ≤ 1. We argue that this non-critical string is given by the topologically twisted non-critical superstring background which provides the dual description of the double-scaled little string theory at the Calabi-Yau singularity. The algorithms developed recently to solve a generic multicut matrix model by means of the loop equations allow to show that the scaling of the higher genus terms in the matrix model free energy matches the expected behaviour in the topological B-model. This result applies to a generic matrix model singularity and the relative double-scaling limit. We use these techniques to explicitly evaluate the free energy at genus one and genus two

  19. Exploring the invisible universe from black holes to superstrings

    CERN Document Server

    Baaquie, Belal E

    2015-01-01

    "Why"? Why is the world, the Universe the way it is? Is space infinitely large? How small is small? What happens when one continues to divide matter into ever smaller pieces? Indeed, what is matter? Is there anything else besides what can be seen? Pursuing the questions employing the leading notions of physics, one soon finds that the tangible and visible world dissolves — rather unexpectedly — into invisible things and domains that are beyond direct perception. A remarkable feature of our Universe is that most of its constituents turn out to be invisible, and this fact is brought out with great force by this book. Exploring the Invisible Universe covers the gamut of topics in advanced modern physics and provides extensive and well substantiated answers to these questions and many more. Discussed in a non-technical, yet also non-trivial manner, are topics dominated by invisible things — such as Black Holes and Superstrings as well as Fields, Gravitation, the Standard Model, Cosmology, Relativity, the O...

  20. U-duality multiplets and nonperturbative superstring states

    International Nuclear Information System (INIS)

    Bars, I.; Yankielowicz, S.

    1996-01-01

    We employ an algebraic approach for unifying perturbative and nonperturbative superstring states on an equal footing, in the form of U-duality multiplets, at all excited string levels. In compactified type-IIA supertring theory we present evidence that the multiplet is labeled by two spaces, open-quote open-quote index close-quote close-quote space and open-quote open-quote base close-quote close-quote space, on which U acts without mixing them. Both spaces are nonperturbative extensions of similar spaces that label perturbative T-duality multiplets. Base space consists of all the central charges of the 11D SUSY algebra, while index space corresponds to representations of the maximal compact subgroup K improper-subset U. This structure predicts the quantum numbers of the nonperturbative states. We also discuss whether and how U multiplets may coexist with 11-dimensional multiplets that are associated with an additional nonperturbative 11D structure that seems to be lurking behind in the underlying theory. copyright 1996 The American Physical Society

  1. A New Metasurface Superstrate Structure for Antenna Performance Enhancement.

    Science.gov (United States)

    Islam, Mohammad Tariqul; Ullah, Mohammad Habib; Singh, Mandeep Jit; Faruque, Mohammad Rashed Iqbal

    2013-07-31

    A new metasurface superstrate structure (MSS)-loaded dual band microstrip line-fed small patch antenna is presented in this paper. The proposed antenna was designed on a ceramic-filled bioplastic sandwich substrate with a high dielectric constant. The proposed 7 × 6 element, square-shaped, single-sided MSS significantly improved the bandwidth and gain of the proposed antenna. The proposed MSS incorporated a slotted patch antenna that effectively increased the measured operating bandwidth from 13.3% to 18.8% and from 14.8% to 23.2% in the lower and upper bands, respectively. Moreover, the average gain of the proposed MSS-based antenna was enhanced from 2.12 dBi to 3.02 dBi in the lower band and from 4.10 dBi to 5.28 dBi in the upper band compared to the patch antenna alone. In addition to the bandwidth and gain improvements, more directive radiation characteristics were also observed from the MSS antenna compared to the patch itself. The effects of the MSS elements and the ground plane length on the reflection coefficient of the antenna were analyzed and optimized. The overall performance makes the proposed antenna appropriate for RFID and WLAN applications.

  2. An induced early mutant in finger millet Eleusin coranaca Gaertn

    International Nuclear Information System (INIS)

    Shivashankar, G.; Kempanna, C.; Viswanatha, S.R.

    1975-01-01

    Among the several collections of ragi (Eleusine coracana. Gaertn.) from all over the world, the strain 'H.E.S.927' has been found to be the highest yielder compared to other cultivars. Mutation studies have been conducted on this variety at Bangalore in India to make it suitable for the rainfall pattern of the ragi tract of the Karnataka state. A mutant induced by gamma radiation at 30 K rad has been stabilized. This mutant is early by 30-35 days with comparatively better straw quality. Various morphological characters concerning the yield and yield attributes and the possibility of exploiting it as a genotype for future breeding work and as a promising variety is discussed. Another promising mutant with earhead measuring 15 cm as against the earhead length of 5 to 10 cm of the cultivated varieties is illustrated. (K.B.)

  3. Functional analysis of chloroplast early light inducible proteins (ELIPs)

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Carolyn M

    2005-02-22

    The objectives of this project were to characterize gene expression patterns of early light inducible protein (ELIP) genes in Arabidopsis thaliana and in Lycopersicon esculentum, to identify knock mutants of the 2 ELIP genes in Arabidopsis, and to characterize the effects of the knockouts. Expression in Arabidopsis was studied in response to thylakoid electron transport chain (PETC) capacity, where it was found that there is a signal for expression associated with reduction of the PETC. Expression in response to salt was also studied, with different responses of the two gene copies. Knockout lines for ELIP1 and ELIP2 have been identified and are being characterized. In tomato, it was found that the single-copy ELIP gene is highly expressed in ripening fruit during the chloroplast-to-chromoplast transition. Studies of expression in tomato ripening mutants are ongoing.

  4. Early-life family structure and microbially induced cancer risk.

    Directory of Open Access Journals (Sweden)

    Martin J Blaser

    2007-01-01

    Full Text Available Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men.We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative, belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0 among those in a sibship of seven or more individuals than in a sibship of between one and three persons.These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

  5. Quantum spectral curve for the η-deformed AdS5 × S5 superstring

    Science.gov (United States)

    Klabbers, Rob; van Tongeren, Stijn J.

    2017-12-01

    The spectral problem for the AdS5 ×S5 superstring and its dual planar maximally supersymmetric Yang-Mills theory can be efficiently solved through a set of functional equations known as the quantum spectral curve. We discuss how the same concepts apply to the η-deformed AdS5 ×S5 superstring, an integrable deformation of the AdS5 ×S5 superstring with quantum group symmetry. This model can be viewed as a trigonometric version of the AdS5 ×S5 superstring, like the relation between the XXZ and XXX spin chains, or the sausage and the S2 sigma models for instance. We derive the quantum spectral curve for the η-deformed string by reformulating the corresponding ground-state thermodynamic Bethe ansatz equations as an analytic Y system, and map this to an analytic T system which upon suitable gauge fixing leads to a Pμ system - the quantum spectral curve. We then discuss constraints on the asymptotics of this system to single out particular excited states. At the spectral level the η-deformed string and its quantum spectral curve interpolate between the AdS5 ×S5 superstring and a superstring on "mirror" AdS5 ×S5, reflecting a more general relationship between the spectral and thermodynamic data of the η-deformed string. In particular, the spectral problem of the mirror AdS5 ×S5 string, and the thermodynamics of the undeformed AdS5 ×S5 string, are described by a second rational limit of our trigonometric quantum spectral curve, distinct from the regular undeformed limit.

  6. Effects of extra light Z bosons in unified and superstring models

    International Nuclear Information System (INIS)

    Barr, S.M.

    1985-07-01

    We discuss the low energy effects of extra light Z bosons in unified models especially in those models which might arise from the E 8 x E' 8 superstring. We find that deviations from the standard model in neutral-current scattering data can give a very sensitive test of the presense of such bosons, of unification, and of the pattern of symmetry breaking. Such deviations have already in fact been observed and seem consistent both with SO(10) and with most of the models arising from the E 8 x E 8 superstring. We also discuss flavor changing effects such as μ → 3e. 11 refs., 3 figs., 1 tab

  7. Manifestly super-Poincare covariant quantization of the Green-Schwarz superstring

    International Nuclear Information System (INIS)

    Nissimov, E.R.; Pacheva, S.J.

    1987-11-01

    The Green-Schwarz (GS) superstring is reformulated in a physically equivalent way by embedding it into a larger system containing additional fermionic string- as well as bosonic harmonic variables and possessing additional gauge invariances. The main feature of the new GS superstring system is that it contains covariant and functionally independent first-class constraints only. This allows straightforward application of the BFV-BRST formalism for a manifestly super-Poincare covariant canonical quantization. The corresponding BRST charge turns out to be of second rank and, therefore, the BFV-BRST action contains fourth order ghost terms. (author). 20 refs

  8. The Born-Infeld action from conformal invariance of the open superstring

    International Nuclear Information System (INIS)

    Bergshoeff, E.; Sezgin, E.; Pope, C.N.; Townsend, P.K.

    1987-01-01

    We show that the one-loop approximation to sigma-model perturbation theory for the open superstring leads to the low energy effective action of Born-Infeld for the gauge field coupled to the ends of the string. Thus the bosonic part of the low-energy open superstring effective action is just that of the open bosonic string. We also show that these results are exact to all-loop orders of sigma-model perturbation theory. (author). 12 refs, 5 figs

  9. Radiation induced early onset of neuro-cognitive changes

    International Nuclear Information System (INIS)

    Kumar, Mayank; Haridas, Seenu; Gupta, Mamta; Trivedi, Richa; Khushu, Subhash; Manda, Kailash

    2012-01-01

    Exposure to ionizing radiations has been shown to cause many detrimental effects. Primarily, the effects observed are broadly classified into hematopoietic syndrome at lower doses, gastrointestinal syndrome and central nervous system dysfunctions at high doses. However, recent studies reported that even at lower doses, there is an effect seen on the nervous system which can be observed as a decline in cognitive abilities. This has been reported in patients undergoing radiotherapy. The cognitive decline, especially in young patients affects development and has been shown to persist for years after the therapy. Thus, the aim of this study was to study and consolidate the early effects of radiation exposure which result in behavioural alterations and cognitive decline. Since, radiation-induced early changes in behavioural functions are poorly understood, therefore, the present investigation aimed to conceptualize and design behavioural test batteries in order to systematically study the immediate alterations in behavioural function following irradiation with a-rays. The behavioural alterations were correlated to changes in the different area of brain like hippocampus, thalamus, hypothalamus and corpus callosum using Diffusion Tensor Imaging (DTI) studies. Present study reported profound changes in behaviour, as well as alterations in the morphology of the brain tissue as perceived by DTI, 48 hours after exposure to ionizing radiations. These changes need to be correlated and clarified further to understand the mechanisms behind the cognitive dysfunctions occurring immediately after radiation exposure as well as to find out a therapeutic window to counteract or reduce the effect of long term cognitive changes following irradiation. (author)

  10. Study on homologous series of induced early mutants in Indica rice Ⅱ. the relationship between the homologous series of early mutants induced and the ecotype in Indica rice

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2001-01-01

    The induced mutation in light sensitivity of the Indica rice leads to induction of the homologous series of early mutants along with the variation of ecological character and the ecoclimate. The induction of mutants was closely related to the ecotype of Indica rice, the homologous series of early mutants in different level were derived from the different ecotype of the Indica rice, otherwise, the similar homologous series of early mutants were derived from the same ecotypic variety. The induction of the early ecotypic variety derived from the homologous series of early mutants provides the basis and possibility for accelerating the development of the new cultivars. (authors)

  11. A natural flipped SU(6) three-generation Calabi-Yau superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Panagiotakopoulos, C. (Theory Div., CERN, Geneva (Switzerland))

    1991-10-24

    We construct a realistic three-generation Calabi-Yau superstring model is which the gauge group SU(6) XU (1) breaks down spontaneously to the standard model group at the compactification scale. Its most remarkable property is the adequate suppression of the proton decay rate without any small trilinear superpotential couplings. (orig.).

  12. Naturally light neutrinos in the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, I.; Rizos, J. (Centre de Physique Theorique, Ecole Polytechnique, 91 - Palaiseau (France)); Tamvakis, K. (Physics Dept., Univ. Ioannina (Greece))

    1992-04-16

    We analyze the SU(5)xU(1)'xU(1){sup 4}xSO(10)xSU(4) superstring model, taking into account non-renormalizable superpotential interactions up to sixth order, and find that all neutrinos stay naturally light within the experimental mass bounds. (orig.).

  13. Jordanian deformations of the AdS5×S5 superstring

    NARCIS (Netherlands)

    Kawaguchi, I.; Matsumoto, T.; Yoshida, K

    2014-01-01

    We consider Jordanian deformations of the AdS_5xS^5 superstring action. The deformations correspond to non-standard q-deformation. In particular, it is possible to perform partial deformations, for example, only for the S^5 part. Then the classical action and the Lax pair are constructed with a

  14. Unification of space-time and internal symmetries through superstrings, with elementary or composite quarks

    International Nuclear Information System (INIS)

    Huebsch, T.

    1987-01-01

    Symmetry properties of a given physical system constrain greatly the theoretical models built in the attempt to describe the system. In complement, the symmetry properties of a system typically undergo dramatic changes during its evolution in time, underpinning the concept of phase transitions. Employing these two ideas we analyze models of Particle Physics at increasingly higher levels of unification, attempting to cover the wide span from the domain of experimentally accessible energies to scales where all the known interactions (including gravity) may be described as low-energy effects of the tremendous and intricate structure of Superstring theories. In particular, we study the scenario of compactification of the Heterotic Superstring theory involving Calabi-Yau manifolds and derive the basic properties of the effective point-field theory action, give a huge class of constructions and devise some techniques for future analysis. Further we study the possibility that the phase-transition from Superstrings to observed particles involves an intermediary phase where the observed particles exhibit compositeness, together with some consequences on the low-energy phenomenology. Finally we include our attempt to modify the SU(5) model, as one of the simplest Grand-unified models, to provide a solution to its difficulties. As we now show, the problems we were trying to address are so generic that some of them remain (in a disguised form) even at the present understanding of the Superstring theories, the most ample constructs of fundamental Physics so far

  15. Superstring motivated gauge models based on a rank six subgroup of E6

    International Nuclear Information System (INIS)

    Lazarides, G.; Panagiotakopoulos, C.; Shafi, Q.

    1987-01-01

    We discuss gauge models based on a superstring motivated rank six subgroup of E 6 . Lepton number is an accidental unbroken symmetry of the models which leads to an essential stable proton. One of the neutral gauge bosons couples to B-L and may have mass below a TeV. (orig.)

  16. Description of a class of superstring compactifications related to semi-simple Lie algebras

    International Nuclear Information System (INIS)

    Markushevich, D.I.; Ol'shanetskij, M.A.; Perelomov, A.M.

    1986-01-01

    A class of vacuum configurations in the superstring theory obtained by compactification of physical dimensions from ten to four is constructed. The compactification scheme involves taking quotients of tori of semisimple Lie algebras by finite symmetry group actions. The complete list of such configurations arising from actions by a Coxeter transformation is given. Some topological invariants having physical interpretations are calculated

  17. Genus one super-Green function revisited and superstring amplitudes with non-maximal supersymmetry

    International Nuclear Information System (INIS)

    Itoyama, H.; Yano, Kohei

    2016-01-01

    We reexamine genus one super-Green functions with general boundary conditions twisted by (α,β) for (σ,τ) directions in the eigenmode expansion and derive expressions as infinite series of hypergeometric functions. Using these, we compute one-loop superstring amplitudes with non-maximal supersymmetry, taking the example of massless vector emissions of open string type I Z 2 orbifold

  18. Foundations of the AdS5 × S5 Superstring Part I

    NARCIS (Netherlands)

    Arutyunov, G.E.; Frolov, S.

    2009-01-01

    We review the recent advances towards finding the spectrum of the AdS_5 x S^5 superstring. We thoroughly explain the theoretical techniques which should be useful for the ultimate solution of the spectral problem. In certain cases our exposition is original and cannot be found in the existing

  19. On the field-antifield (a)symmetry of the pure spinor superstring

    Czech Academy of Sciences Publication Activity Database

    Lipinski Jusinskas, Renann

    2015-01-01

    Roč. 2015, č. 12 (2015), s. 136 ISSN 1029-8479 R&D Projects: GA ČR GBP201/12/G028 Institutional support: RVO:68378271 Keywords : superstrings and heterotic strings * superspaces Subject RIV: BD - Theory of Information Impact factor: 6.023, year: 2015

  20. Simplified pure spinor b ghost in a curved heterotic superstring background

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, Nathan [ICTP South American Institute for Fundamental Research,Instituto de Física Teórica, UNESP - Universidade Estadual Paulista,Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil); Chandia, Osvaldo [Departamento de Ciencias, Facultad de Artes Liberales,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile)

    2014-06-03

    Using the RNS-like fermionic vector variables introduced in arXiv:1305.0693, the pure spinor b ghost in a curved heterotic superstring background is easily constructed. This construction simplifies and completes the b ghost construction in a curved background of arXiv:1311.7012.

  1. Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    1999-01-01

    The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

  2. Search for new quarks suggested by the superstring

    International Nuclear Information System (INIS)

    Angelopoulos, V.D.; Zwirner, F.

    1987-01-01

    We discuss the possible phenomenology of the additional charge (-1/3) colour triplet particles D 1/2 of spin 1/2 and D 0 , anti D 0 c of spin 0 which are contained in each matter generation if the superstring is compactified on a Calabi-Yau manifold. In the minimal model with no intermediate mass scales and supersymmetry breaking fed into the observable sector via a gaugino mass, either a spin-1/2 or a spin-0 D particle could be the lightest, and either could be as light as the present lower bound from e + e - experiments of about 20 GeV. The D particles could behave as leptoquarks coupling to quarks and leptons, in which case the single production process ep → D 0 (anti D 0 c )+X would occur, and D 0 (anti D 0 c ) → lq, D 1/2 → lq χ tilde decays would dominate, where χ tilde is the lightest supersymmetric particle. Alternatively, the D particles could behave as diquarks coupling to pairs of antiquarks, in which case the single production process anti pp → D 0 (anti D 0 c , anti D 0 , D 0 c )+X would occur, and D 0 (anti D 0 c ) → anti qanti q, D 0 c (anti D 0 ) → qq, D 1/2 → anti qanti q χ tilde decays would dominate. We present cross sections for ep → D 0 (anti D 0 c )+X, anti pp → D 0 (anti D 0 c , D 0 c , anti D 0 )+X, e + e - → D 0 anti D 0 (D 0 c anti D 0 c ) and D 1/2 anti D 1/2 , anti pp → D 0 anti D 0 (D 0 c anti D 0 c ) and D 1/2 anti D 1/2 +X. We calculate the experimental signals and estimate backgrounds for D production and decay in these processes. The decays D 0 (anti D 0 c ) → lq and D 1/2 → lq χ tilde or anti qanti q χ tilde would be detectable in most of these reactions, but D 0 (anti D 0 c ) → anti qanti q decays may only be detectable in e + e - → D 0 anti D 0 (D 0 c anti D 0 c ) collisions. (orig.)

  3. String Theory Volume 1: An Introduction to the Bosonic String and Volume 2: Superstring Theory and Beyond

    Energy Technology Data Exchange (ETDEWEB)

    Carlip, S [Department of Physics, University of California, Davis, CA 95616 (United States)

    2006-10-21

    The early 1980s, when I first learned theory, were desperate times for graduate students. We searched frantically for coherent introductions, passing tattered copies of review articles around like samizdat, struggling over obscure references to ancient models of strong interactions, and flocking to lectures-not least those by Joe Polchinski-that promised to really explain what was going on. If only this book had been around, it would have saved much grief. Volume I, The Bosonic String, offers a clear and well organized introduction to bosonic string theory. Topics range from the 'classical' (spectra, vertex operators, consistency conditions, etc.) to the 'modern' (D-branes first appear in an exercise at the end of chapter 1, noncommutative geometry shows up in chapter 8). Polchinski does not hesitate to discuss sophisticated matters-path integral measures, BRST symmetries, etc.-but his approach is pedagogical, and his writing is lucid, if sometimes a bit terse. Chapters end with problems that are sometimes difficult but never impossible. A very useful annotated bibliography directs readers to resources for further study, and a nearly 30-page glossary provides short but clear definitions of key terms. There is much here that will appeal to relativists. Polchinski uses the covariant Polyakov path integral approach to quantization from early on; he clearly distinguishes Weyl invariance from conformal invariance; he is appropriately careful about using complex coordinates on topologically nontrivial manifolds; he keeps the string world sheet metric explicit at the start instead of immediately hiding it by a gauge choice. Volume II includes an elegant introduction to anticommuting coordinates and superconformal transformations. A few conventions may cause confusion-%, Polchinski's stress-energy tensor, for instance, differs from the standard general relativistic definition by a factor of -2{pi}, and while this is briefly mentioned in the text

  4. Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity

    Science.gov (United States)

    Zhao, Lina; Fu, Zhuo; Wu, Jing; Aylor, Kevin W.; Barrett, Eugene J.; Cao, Wenhong

    2015-01-01

    Endothelial dysfunction and vascular insulin resistance usually coexist and chronic inflammation engenders both. In the present study, we investigate the temporal relationship between vascular insulin resistance and metabolic insulin resistance. We assessed insulin responses in all arterial segments, including aorta, distal saphenous artery and the microvasculature, as well as the metabolic insulin responses in muscle in rats fed on a high-fat diet (HFD) for various durations ranging from 3 days to 4 weeks with or without sodium salicylate treatment. Compared with controls, HFD feeding significantly blunted insulin-mediated Akt (protein kinase B) and eNOS [endothelial nitric oxide (NO) synthase] phosphorylation in aorta in 1 week, blunted vasodilatory response in small resistance vessel in 4 weeks and microvascular recruitment in as early as 3 days. Insulin-stimulated whole body glucose disposal did not begin to progressively decrease until after 1 week. Salicylate treatment fully inhibited vascular inflammation, prevented microvascular insulin resistance and significantly improved muscle metabolic responses to insulin. We conclude that microvascular insulin resistance is an early event in diet-induced obesity and insulin resistance and inflammation plays an essential role in this process. Our data suggest microvascular insulin resistance contributes to the development of metabolic insulin resistance in muscle and muscle microvasculature is a potential therapeutic target in the prevention and treatment of diabetes and its related complications. PMID:26265791

  5. Superstrate loading effects on the resonant characteristics of high Tc superconducting circular patch printed on anisotropic materials

    Science.gov (United States)

    Bedra, Sami; Bedra, Randa; Benkouda, Siham; Fortaki, Tarek

    2017-12-01

    In this paper, the effects of both anisotropies in the substrate and superstrate loading on the resonant frequency and bandwidth of high-Tc superconducting circular microstrip patch in a substrate-superstrate configuration are investigated. A rigorous analysis is performed using a dyadic Galerkin's method in the vector Hankel transform domain. Galerkin's procedure is employed in the spectral domain where the TM and TE modes of the cylindrical cavity with magnetic side walls are used in the expansion of the disk current. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. London's equations and the two-fluid model of Gorter and Casimir are used in the calculation of the complex surface impedance of the superconducting circular disc. The accuracy of the analysis is tested by comparing the computed results with previously published data for several anisotropic substrate-superstrate materials. Good agreement is found among all sets of results. The numerical results obtained show that important errors can be made in the computation of the resonant frequencies and bandwidths of the superconducting resonators when substrate dielectric anisotropy, and/or superstrate anisotropy are ignored. Other theoretical results obtained show that the superconducting circular microstrip patch on anisotropic substrate-superstrate with properly selected permittivity values along the optical and the non-optical axes combined with optimally chosen structural parameters is more advantageous than the one on isotropic substrate-superstrate by exhibiting wider bandwidth characteristic.

  6. Biomarkers for the early detection of cancer treatment induced cardiotoxicity

    NARCIS (Netherlands)

    Bulten, Ben

    2016-01-01

    In this thesis, the role of several imaging and nonimaging markers for the detection of anthracycline-induced and trastuzumab-induced cardiotoxicity (respectively AIC and TIC) is evaluated. Especially, the pathophysiology of these processes and the interrelationship of the various markers are

  7. The Yang monopole in IIA superstring: multi-charge disease and enhançon cure

    International Nuclear Information System (INIS)

    Belhaj, Adil; Diaz, Pablo; Segui, Antonio

    2012-01-01

    A brane picture in type IIA superstring for the Yang monopole is reconsidered. It makes use of D2 and D4-branes wrapped on cycles in the K3 surface. When the model was first presented, some problems concerning the charges of the monopoles arose. In this paper, they are shown to be cured by the model itself. Surprisingly, the incompatibility between the multi-charge configuration and the spherical symmetry of the Yang monopole is seen in the brane description as the emergence of the enhançon shell and the fuzzy geometry. This consistency is deep and surprising, and is the point that triggered this work. It nontrivially relates a purely geometrical problem in ordinary spacetime with the emergence of noncommutative geometries. Besides, this paper includes an extended model for SO(4)-monopoles and a T-dual model in type IIB superstring. (paper)

  8. On pure spinor formalism for quantum superstring and spinor moving frame

    International Nuclear Information System (INIS)

    Bandos, Igor A

    2013-01-01

    The D = 10 pure spinor constraint can be solved in terms of spinor moving frame variables v -α q and eight-component complex null vector Λ + q , Λ + q Λ + q =0, which can be related to the κ-symmetry ghost. Using this and similar solutions for the conjugate pure spinor and other elements of the non-minimal pure spinor formalism, we present a (hopefully useful) reformulation of the measure of the pure spinor path integral for superstring in terms of products of Cartan forms corresponding to the coset of 10D Lorentz group and to the coset of complex orthogonal group SO(8, C). Our study suggests a possible complete reformulation of the pure spinor superstring in terms of new irreducible set of variable. (paper)

  9. The AdS5xS5 superstring worldsheet S matrix and crossing symmetry

    International Nuclear Information System (INIS)

    Janik, Romuald A.

    2006-01-01

    An S matrix satisfying the Yang-Baxter equation with symmetries relevant to the AdS 5 xS 5 superstring recently has been determined up to an unknown scalar factor. Such scalar factors are typically fixed using crossing relations; however, due to the lack of conventional relativistic invariance, in this case its determination remained an open problem. In this paper we propose an algebraic way to implement crossing relations for the AdS 5 xS 5 superstring worldsheet S matrix. We base our construction on a Hopf-algebraic formulation of crossing in terms of the antipode and introduce generalized rapidities living on the universal cover of the parameter space which is constructed through an auxillary, coupling-constant dependent, elliptic curve. We determine the crossing transformation and write functional equations for the scalar factor of the S matrix in the generalized rapidity plane

  10. Real analytic solutions for marginal deformations in open superstring field theory

    International Nuclear Information System (INIS)

    Okawa, Yuji

    2007-01-01

    We construct analytic solutions for marginal deformations satisfying the reality condition in open superstring field theory formulated by Berkovits when operator products made of the marginal operator and the associated superconformal primary field are regular. Our strategy is based on the recent observation by Erler that the problem of finding solutions for marginal deformations in open superstring field theory can be reduced to a problem in the bosonic theory of finding a finite gauge parameter for a certain pure-gauge configuration labeled by the parameter of the marginal deformation. We find a gauge transformation generated by a real gauge parameter which infinitesimally changes the deformation parameter and construct a finite gauge parameter by its path-ordered exponential. The resulting solution satisfies the reality condition by construction

  11. A low energy dynamical SUSY breaking scenario motivated from superstring derived unification

    CERN Document Server

    Faraggi, Alon E.

    1996-01-01

    Recently there has been a resurgence of interest in gauge mediated dynamical supersymmetry breaking scenarios. I investigate how low energy dynamical SUSY breaking may arise from superstring models. In a three generation string derived model I propose that the unbroken hidden non--Abelian gauge group at the string scale is SU(3)_H with matter multiplets. Due to the small gauge content of the hidden gauge group the supersymmetry breaking scale may be consistent with the dynamical SUSY breaking scenarios. The messenger states are obtained in the superstring model from sectors which arise due to the ``Wilson--line'' breaking of the unifying non--Abelian gauge symmetry. An important property of the string motivated messenger states is the absence of superpotential terms with the Standard Model states. The stringy symmetries therefore forbid the flavor changing processes which may arise due to couplings between the messenger sector states and the Standard Model states. Motivated from the problem of string gauge co...

  12. Real analytic solutions for marginal deformations in open superstring field theory

    International Nuclear Information System (INIS)

    Okawa, Y.

    2007-04-01

    We construct analytic solutions for marginal deformations satisfying the reality condition in open superstring field theory formulated by Berkovits when operator products made of the marginal operator and the associated superconformal primary field are regular. Our strategy is based on the recent observation by Erler that the problem of finding solutions for marginal deformations in open superstring field theory can be reduced to a problem in the bosonic theory of finding a finite gauge parameter for a certain pure-gauge configuration labeled by the parameter of the marginal deformation. We find a gauge transformation generated by a real gauge parameter which infinitesimally changes the deformation parameter and construct a finite gauge parameter by its path-ordered exponential. The resulting solution satisfies the reality condition by construction. (orig.)

  13. Super-Poincare covariant canonical formulation of superparticles and Green-Schwarz superstrings

    International Nuclear Information System (INIS)

    Nissimov, E.R.; Pacheva, S.J.

    1987-11-01

    First, a new unified covariant formulation simultaneously describing both superparticles and spinning particles is proposed. In this formulation both models emerge as different gauge fixings from a more general point-particle model with larger and gauge invariance. The general model possesses covariant and functionally independent first-class constraints only. Next, the above construction is generalized to the case of Green-Schwarz (GS) superstrings. This allows straightforward application of the Batalin-Fradkin-Vilkovisky (BFV) Becchi-Rouet-Stora-Tyutin (BRST) formalism for a manifestly super-Poincare covariant canonical quantization. The corresponding BRST charge turns out to be remarkably simple and is of rank one. It is used to construct a covariant BFV Hamiltonian for the GS superstring exhibiting explicit Parisi-Sourlas OSp(1,1/2) symmetry. (author). 21 refs

  14. Field Enhancement in a Grounded Dielectric Slab by Using a Single Superstrate Layer

    OpenAIRE

    Valagiannopoulos, Constantinos A.; Tsitsas, Nikolaos L.

    2012-01-01

    The addition of a dielectric layer on a slab configuration is frequently utilized in various electromagnetic devices in order to give them certain desired operational characteristics. In this work, we consider a grounded dielectric film-slab, which is externally excited by a normally-incident Gaussian beam. On top of the film-slab, we use an additional suitably selected single isotropic superstrate layer in order to increase the field concentration inside the slab and hence achieve optimal po...

  15. Green-Schwarz superstring theory in two dimensions and topological field theories

    International Nuclear Information System (INIS)

    Igarashi, Yuji; Kubo, Jisuke

    1991-01-01

    It is shown that the algebra associated with the local Κ-supersymmetry in the Green-Schwarz superstring theory in d=2 dimensions closes of shell. We quantize the theory in a Lorentz covariant fashion by using the generalized hamiltonian method of Batalin, Fradkin and Vilkovisky and derive a quantum mechanically consistent, gauge-fixed theory, which can be interpreted as a Κ-supersymmetric extension of conformal topological gravity. (orig.)

  16. The Big Bang, Superstring Theory and the origin of life on the Earth.

    Science.gov (United States)

    Trevors, J T

    2006-03-01

    This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.

  17. A large class of new gravitational and axionic backgrounds for four-dimensional superstrings

    CERN Document Server

    Kiritsis, Elias B; Lüst, Dieter

    1994-01-01

    A large class of new 4-D superstring vacua with non-trivial/singular geometries, spacetime supersymmetry and other background fields (axion, dilaton) are found. Killing symmetries are generic and are associated with non-trivial dilaton and antisymmetric tensor fields. Duality symmetries preserving N=2 superconformal invariance are employed to generate a large class of explicit metrics for non-compact 4-D Calabi-Yau manifolds with Killing symmetries.

  18. Quantization of the Type II superstring in a curved six-dimensional background

    International Nuclear Information System (INIS)

    Berkovits, Nathan

    2000-01-01

    A sigma model action with N=2 D=6 superspace variables is constructed for the Type II superstring compactified to six curved dimensions with Ramond-Ramond flux. The action can be quantized since the sigma model is linear when the six-dimensional space-time is flat. When the six-dimensional space-time is AdS 3 xS 3 , the action reduces to one found earlier with Vafa and Witten

  19. A singular one-parameter family of solutions in cubic superstring field theory

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo, E. Aldo [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, 09210-170 São Paulo, SP (Brazil)

    2016-05-03

    Performing a gauge transformation of a simple identity-like solution of superstring field theory, we construct a one-parameter family of solutions, and by evaluating the energy associated to this family, we show that for most of the values of the parameter the solution represents the tachyon vacuum, except for two isolated singular points where the solution becomes the perturbative vacuum and the half brane solution.

  20. Field Enhancement in a Grounded Dielectric Slab by Using a Single Superstrate Layer

    Directory of Open Access Journals (Sweden)

    Constantinos A. Valagiannopoulos

    2012-01-01

    Full Text Available The addition of a dielectric layer on a slab configuration is frequently utilized in various electromagnetic devices in order to give them certain desired operational characteristics. In this work, we consider a grounded dielectric film-slab, which is externally excited by a normally-incident Gaussian beam. On top of the film-slab, we use an additional suitably selected single isotropic superstrate layer in order to increase the field concentration inside the slab and hence achieve optimal power transfer from the external source to the internal region. We define a quantity of interest, called “enhancement factor,” expressing the increase of the field concentration in the film-slab when the superstrate is present compared to the case that it is absent. It is shown that large enhancement factor values may be achieved by choosing properly the permittivity, the permeability, and the thickness of the superstrate. In particular, it is demonstrated that the field in the film-slab is significantly enhanced when the slab is composed by an ϵ-near-zero (ENZ or low-index metamaterial.

  1. T-dualization of type II superstring theory in double space

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, B.; Sazdovic, B. [University of Belgrade, Institute of Physics Belgrade, Belgrade (Serbia)

    2017-03-15

    In this article we offer a new interpretation of the T-dualization procedure of type II superstring theory in the double space framework. We use the ghost free action of type II superstring in pure spinor formulation in approximation of constant background fields up to the quadratic terms. T-dualization along any subset of the initial coordinates, x{sup a}, is equivalent to the permutation of this subset with subset of the corresponding T-dual coordinates, y{sub a}, in double space coordinate Z{sup M} = (x{sup μ}, y{sub μ}). Requiring that the T-dual transformation law after the exchange x{sup a} <-> y{sub a} has the same form as the initial one, we obtain the T-dual NS-NS and NS-R background fields. The T-dual R-R field strength is determined up to one arbitrary constant under some assumptions. The compatibility between supersymmetry and T-duality produces a change of bar spinors and R-R field strength. If we dualize an odd number of dimensions x{sup a}, such a change flips type IIA/B to type II B/A. If we T-dualize the time-like direction, one imaginary unit i maps type II superstring theories to type II{sup *} ones. (orig.)

  2. On the absence of large-order divergences in superstring theory

    International Nuclear Information System (INIS)

    Davis, S.

    2003-01-01

    The genus-dependence of multi-loop superstring amplitudes is estimated at large orders in perturbation theory using the super-Schottky group parameterization of supermoduli space. Restriction of the integration region to a subset of supermoduli space and a single fundamental domain of the super-modular group suggests an exponential dependence on the genus. Upper bounds for these estimates are obtained for arbitrary N-point superstring scattering amplitudes and are shown to be consistent with exact results obtained for special type II string amplitudes for orbifold or Calabi-Yau compactifications. The genus-dependence is then obtained by considering the effect of the remaining contribution to the superstring amplitudes after the coefficients of the formally divergent parts of the integrals vanish as a result of a sum over spin structures. The introduction of supersymmetry therefore leads to the elimination of large-order divergences in string perturbation theory, a result which is based only on the supersymmetric generalization of the Polyakov measure and not the gauge group of the string model. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  3. Two-loop superstrings IV The cosmological constant and modular forms

    International Nuclear Information System (INIS)

    D'Hoker, E.; Phong, D.H.

    2002-01-01

    The slice-independent gauge-fixed superstring chiral measure in genus 2 derived in the earlier papers of this series for each spin structure is evaluated explicitly in terms of theta-constants. The slice-independence allows an arbitrary choice of superghost insertion points q 1 ,q 2 in the explicit evaluation, and the most effective one turns out to be the split gauge defined by S δ (q 1 ,q 2 )=0. This results in expressions involving bilinear theta-constants M. The final formula in terms of only theta-constants follows from new identities between M and theta-constants which may be interesting in their own right. The action of the modular group Sp(4,Z) is worked out explicitly for the contribution of each spin structure to the superstring chiral measure. It is found that there is a unique choice of relative phases which insures the modular invariance of the full chiral superstring measure, and hence a unique way of implementing the GSO projection for even spin structure. The resulting cosmological constant vanishes, not by a Riemann identity, but rather by the genus 2 identity expressing any modular form of weight 8 as the square of a modular form of weight 4. The degeneration limits for the contribution of each spin structure are determined, and the divergences, before the GSO projection, are found to be the ones expected on physical grounds

  4. Anthracycline-induced cardiotoxicity, a pathophysiology based approach for early detection and protective strategies

    NARCIS (Netherlands)

    Broeyer, Frederik Jan Ferdinand

    2012-01-01

    In this thesis the development of a pathophysiology-based method for the early evaluation of anthracycline-induced cardiotoxicity was described. We evaluated a comprehensive array of biomarkers, representing several aspects of anthracycline-induced cardiotoxicity, including cardiac injury and

  5. Endothelial glycocalyx degradation induces endogenous heparinization in patients with severe injury and early traumatic coagulopathy

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Johansson, Pär I

    2012-01-01

    There is emerging evidence that early trauma-induced coagulopathy (TIC) is mechanistically linked to disruption of the vascular endothelium and its glycocalyx, assessed by thrombomodulin and syndecan 1, respectively. This study evaluated if degradation of the endothelial glycocalyx and ensuing...... release of its heparin-like substances induce autoheparinization and thereby contributes to TIC....

  6. String Theory Volume 1: An Introduction to the Bosonic String and Volume 2: Superstring Theory and Beyond

    International Nuclear Information System (INIS)

    Carlip, S

    2006-01-01

    The early 1980s, when I first learned theory, were desperate times for graduate students. We searched frantically for coherent introductions, passing tattered copies of review articles around like samizdat, struggling over obscure references to ancient models of strong interactions, and flocking to lectures-not least those by Joe Polchinski-that promised to really explain what was going on. If only this book had been around, it would have saved much grief. Volume I, The Bosonic String, offers a clear and well organized introduction to bosonic string theory. Topics range from the 'classical' (spectra, vertex operators, consistency conditions, etc.) to the 'modern' (D-branes first appear in an exercise at the end of chapter 1, noncommutative geometry shows up in chapter 8). Polchinski does not hesitate to discuss sophisticated matters-path integral measures, BRST symmetries, etc.-but his approach is pedagogical, and his writing is lucid, if sometimes a bit terse. Chapters end with problems that are sometimes difficult but never impossible. A very useful annotated bibliography directs readers to resources for further study, and a nearly 30-page glossary provides short but clear definitions of key terms. There is much here that will appeal to relativists. Polchinski uses the covariant Polyakov path integral approach to quantization from early on; he clearly distinguishes Weyl invariance from conformal invariance; he is appropriately careful about using complex coordinates on topologically nontrivial manifolds; he keeps the string world sheet metric explicit at the start instead of immediately hiding it by a gauge choice. Volume II includes an elegant introduction to anticommuting coordinates and superconformal transformations. A few conventions may cause confusion-%, Polchinski's stress-energy tensor, for instance, differs from the standard general relativistic definition by a factor of -2π, and while this is briefly mentioned in the text, it could easily be missed

  7. 3-D Printed Fabry–Pérot Resonator Antenna with Paraboloid-Shape Superstrate for Wide Gain Bandwidth

    Directory of Open Access Journals (Sweden)

    Qiang Chen

    2017-11-01

    Full Text Available A three-dimensional (3-D printed Fabry–Pérot resonator antenna (FPRA, which designed with a paraboloid-shape superstrate for wide gain bandwidth is proposed. In comparison with the commonly-adopted planar superstrate, the paraboloid-shape superstrate is able to provide multiple resonant heights and thus satisfy the resonant condition of the FPRA in a wide frequency band. A FPRA working at 6 GHz is designed, fabricated, and tested. Considering the fabrication difficulty caused by its complex structure, the prototype antenna was fabricated by using the 3-D printing technology, i.e., all components of the prototype antenna were printed with photopolymer resin and then treated by the surface metallization process. Measurement results agree well with the simulation results, and show the 3-D printed FPRA has a |S11| < −10 dB impedance bandwidth of 12.4%, and a gain of 16.8 dBi at its working frequency of 6 GHz. Moreover, in comparison with the planar superstrate adopted in traditional FPRAs, the paraboloid-shape superstrate of the proposed FPRA significantly improves the 3-dB gain bandwidth from 6% to 22.2%.

  8. Gamma-ray-induced bold seeded early maturing groundnut selections

    Energy Technology Data Exchange (ETDEWEB)

    Manoharan, V; Thangavelu, S [Regional Research Station, Vriddhachalam, Tamil Nadu (India)

    1990-07-01

    Full text: ''Chico'' is an early maturing (85-90 days) erect groundnut (Arachis hypogaea L.) genotype utilised in groundnut improvement to incorporate earliness in high yielding varieties. Though it has high shelling out-turn, its yield potential is low since it has small seeds. Mutation breeding was started with the objective of improving the seed size. In a preliminary experiment, dry seeds were treated with 20, 30, 40 or 50 kR of gamma rays. The M{sub 1} generation was grown during the post rainy season of 1988-1989. The M{sub 2} generation was planted as individual plant progeny rows during the rainy season of 1989. 105 progeny rows were studied, the total number of M{sub 2} plants being 1,730. All the M{sub 2} plants were harvested 90 days after sowing. Seven mutants with bold seed size were obtained. The mutants had 100 kernel weight ranging from 22.2 to 40.4 g compared to 21.1 g of control. The study is in progress. (author)

  9. Gamma-ray-induced bold seeded early maturing groundnut selections

    International Nuclear Information System (INIS)

    Manoharan, V.; Thangavelu, S.

    1990-01-01

    Full text: ''Chico'' is an early maturing (85-90 days) erect groundnut (Arachis hypogaea L.) genotype utilised in groundnut improvement to incorporate earliness in high yielding varieties. Though it has high shelling out-turn, its yield potential is low since it has small seeds. Mutation breeding was started with the objective of improving the seed size. In a preliminary experiment, dry seeds were treated with 20, 30, 40 or 50 kR of gamma rays. The M 1 generation was grown during the post rainy season of 1988-1989. The M 2 generation was planted as individual plant progeny rows during the rainy season of 1989. 105 progeny rows were studied, the total number of M 2 plants being 1,730. All the M 2 plants were harvested 90 days after sowing. Seven mutants with bold seed size were obtained. The mutants had 100 kernel weight ranging from 22.2 to 40.4 g compared to 21.1 g of control. The study is in progress. (author)

  10. TRMM Applications for Rainfall-Induced Landslide Early Warning

    Science.gov (United States)

    Dok, A.; Fukuoka, H.; Hong, Y.

    2012-04-01

    Early warning system (EWS) is the most effective method in saving lives and reducing property damages resulted from the catastrophic landslides if properly implemented in populated areas of landslide-prone nations. For predicting the occurrence of landslides, it requires examination of empirical relationship between rainfall characteristics and past landslide occurrence. In developed countries like Japan and the US, precipitation is monitored by rain radars and ground-based rain gauge matrix. However, in developing regions like Southeast Asian countries, very limited number of rain gauges is available, and there is no implemented methodology for issuing effective warming of landslides yet. Correspondingly, satellite precipitation monitoring could be therefore a possible and promising solution for launching landslide quasi-real-time early warning system in those countries. It is due to the fact that TMPA (TRMM Multi-satellite Precipitation Analysis) can provides a globally calibration-based sequential scheme for combining precipitation estimates from multiple satellites, and gauge analyses where feasible, at fine scales (3-hourly with 0.25°x0.25° spatial resolution). It is available both after and in quasi-real time, calibrated by TRMM Combined Instrument and TRMM Microwave Imager precipitation product. However, validation of ground based rain gauge and TRMM satellite data in the vulnerable regions is still not yet operative. Snake-line/Critical-line and Soil Water Index (SWI) are used for issuing warning of landslide occurrence in Japan; whereas, Caine criterion is preferable in Europe and western nations. Herewith, it presents rainfall behavior which took place in Beichuan city (located on the 2008 Chinese Wenchuan earthquake fault), Hofu and Shobara cities in Japan where localized heavy rainfall attacked in 2009 and 2010, respectively, from TRMM 3B42RT correlated with ground based rain gauge data. The 1-day rainfall intensity and 15-day cumulative rainfall

  11. Early attentional bias for negative words when competition is induced.

    Science.gov (United States)

    Ho, Ming-Chou; Li, Shuo-Heng; Yeh, Su-Ling

    2016-05-01

    Previous research (Zeelenberg, Wagenmakers, & Rotteveel, 2006) revealed that emotionally meaningful words were identified significantly better than neutral words, with no difference between positive and negative words. Since in that study only a single target word was displayed at a time, we hypothesized that the equivalent performances for positive and negative words were due to a lack of competition. To test this, in our Experiment 1, we replicated Zeelenberg and colleagues' finding, using emotion-laden Chinese words and the identical data-limited method, which measured the accuracy of a briefly shown target. We then introduced competition in Experiment 2 by simultaneously presenting two words during the target frame, and found evidence for an early attentional bias to negative words. In Experiment 3, we confirmed that the bias in Experiment 2 was not due to the inevitable repetition of stimuli. Taken together, these results support our hypothesis that, in the presence of competition, negative words receive attentional priority and consequently have enhanced perceptual representations.

  12. Fibrinogen depletion in trauma: early, easy to estimate and central to trauma-induced coagulopathy

    OpenAIRE

    Davenport, Ross; Brohi, Karim

    2013-01-01

    Fibrinogen is fundamental to hemostasis and falls rapidly in trauma hemorrhage, although levels are not routinely measured in the acute bleeding episode. Prompt identification of critically low levels of fibrinogen and early supplementation has the potential to correct trauma-induced coagulation and improve outcomes. Early estimation of hypofibrinogenemia is possible using surrogate markers of shock and hemorrhage; for example, hemoglobin and base excess. Rapid replacement with fibrinogen con...

  13. Fibrinogen depletion in trauma: early, easy to estimate and central to trauma-induced coagulopathy.

    Science.gov (United States)

    Davenport, Ross; Brohi, Karim

    2013-09-24

    Fibrinogen is fundamental to hemostasis and falls rapidly in trauma hemorrhage, although levels are not routinely measured in the acute bleeding episode. Prompt identification of critically low levels of fibrinogen and early supplementation has the potential to correct trauma-induced coagulation and improve outcomes. Early estimation of hypofibrinogenemia is possible using surrogate markers of shock and hemorrhage; for example, hemoglobin and base excess. Rapid replacement with fibrinogen concentrate or cryoprecipitate should be considered a clinical priority in major trauma hemorrhage.

  14. Clozapine-Induced Myocarditis: Is Mandatory Monitoring Warranted for Its Early Recognition?

    Directory of Open Access Journals (Sweden)

    T. A. Munshi

    2014-01-01

    Full Text Available Clozapine is an atypical antipsychotic used for treatment resistant schizophrenia. Its potential to induce agranulocytosis is well known but it can also cause myocarditis. Clozapine is the only antipsychotic known to induce this side effect, typically early in the treatment, and literature is scarce on this condition. We are presenting a case report of a 21-year-old schizophrenic male who developed myocarditis within 3 weeks of starting on clozapine for his treatment resistant psychosis. We then aim to review some of the available literature and raise awareness among physicians as this condition can potentially be fatal if not detected early.

  15. Early remodeling of rat cardiac muscle induced by swimming training

    Directory of Open Access Journals (Sweden)

    Verzola R.M.M.

    2006-01-01

    Full Text Available The aim of the present investigation was to study the effect of acute swimming training with an anaerobic component on matrix metallopeptidase (MMP activity and myosin heavy chain gene expression in the rat myocardium. Animals (male Wistar rats, weighing approximately 180 g were trained for 6 h/day in 3 sessions of 2 h each for 1 to 5 consecutive days (N = 5 rats per group. Rats swam in basins 47 cm in diameter and 60 cm deep filled with water at 33 to 35ºC. After the training period a significant increase (P < 0.05 was observed in the heart weight normalized to body weight by about 22 and 35% in the groups that trained for 96 and 120 h, respectively. Blood lactate levels were significantly increased (P < 0.05 in all groups after all training sessions, confirming an anaerobic component. However, lactate levels decreased (P < 0.05 with days of training, suggesting that the animals became adapted to this protocol. Myosin heavy chain-ß gene expression, analyzed by real time PCR and normalized with GAPDH gene expression, showed a significant two-fold increase (P < 0.01 after 5 days of training. Zymography analysis of myocardium extracts indicated a single ~60-kDa activity band that was significantly increased (P < 0.05 after 72, 96, and 120 h, indicating an increased expression of MMP-2 and suggesting precocious remodeling. Furthermore, the presence of MMP-2 was confirmed by Western blot analysis, but not the presence of MMP-1 and MMP-3. Taken together, our results indicate that in these training conditions, the rat heart undergoes early biochemical and functional changes required for the adaptation to the new physiological condition by tissue remodeling.

  16. Attractions to radiation-like eras in superstring cosmologies

    CERN Document Server

    Partouche, Herve

    2010-01-01

    We review the cosmology induced by finite temperature and quantum effects on non-supersymmetric string models. We show the evolution is attracted to radiation-like solutions after the Hagedorn era and before the electroweak phase transition. This mechanism generates a hierarchy between the Planck mass and the supersymmetry breaking scale. A dynamical change of space-time dimension can take place.

  17. High‐Volume Processed, ITO‐Free Superstrates and Substrates for Roll‐to‐Roll Development of Organic Electronics

    DEFF Research Database (Denmark)

    Hösel, Markus; Angmo, Dechan; Søndergaard, Roar R.

    2014-01-01

    The fabrication of substrates and superstrates prepared by scalable roll-to-roll methods is reviewed. The substrates and superstrates that act as the flexible carrier for the processing of functional organic electronic devices are an essential component, and proposals are made about how the general...... availability of various forms of these materials is needed to accelerate the development of the field of organic electronics. The initial development of the replacement of indium-tin-oxide (ITO) for the flexible carrier materials is described and a description of how roll-to-roll processing development led...

  18. Constraints from proton decay in the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Leontaris, G.K.; Tamvakis, K. (Ioannina Univ. (Greece). Theoretical Physics Div.)

    1991-05-16

    We discuss the constraints the emerge from the existence of dimension-5 baryon-violating operators in the flipped SU(5) x U(1) superstring model. These are constraints on matter field assignments and on singlet VEV values. Although baryon-violating dimension-5 operators that appear as quintic non-renormalizable terms vanish as has been proven before and as we verify here, effective dimension-5 operators resulting from Higgs exchange put non-trivial but feasible constraints on the model. Constraints are also extracted from the presence of higher order non-renormalizable terms that generate such operators which do not a priori vanish. (orig.).

  19. Covariant map between Ramond-Neveu-Schwarz and pure spinor formalisms for the superstring

    International Nuclear Information System (INIS)

    Berkovits, Nathan

    2014-01-01

    A covariant map between the Ramond-Neveu-Schwarz (RNS) and pure spinor formalisms for the superstring is found which transforms the RNS and pure spinor BRST operators into each other. The key ingredient is a dynamical twisting of the ten spin-half RNS fermions into five spin-one and five spin-zero fermions using bosonic pure spinors that parameterize an SO(10)/U(5) coset. The map relates massless vertex operators in the two formalisms, and gives a new description of Ramond states which does not require spin fields. An argument is proposed for relating the amplitude prescriptions in the two formalisms

  20. Open superstring field theory I: gauge fixing, ghost structure, and propagator

    Czech Academy of Sciences Publication Activity Database

    Kroyter, M.; Okawa, Y.; Schnabl, Martin; Torii, S.; Zwiebach, B.

    2012-01-01

    Roč. 2012, č. 3 (2012), 1-34 ISSN 1126-6708 R&D Projects: GA MŠk(CZ) LH11106 Grant - others:EUROHORC and ESF(XE) EYI/07/E010 Institutional research plan: CEZ:AV0Z10100502 Keywords : superstrings and heterotic strings * string field theory Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.618, year: 2012 http://link.springer.com/article/10.1007%2FJHEP03%282012%29030

  1. Signatures of exotic fermions and other new ''low-energy'' phenomena in superstring E6

    International Nuclear Information System (INIS)

    Rosner, J.L.

    1986-03-01

    Superstring theories have drawn renewed attention to the exceptional group E 6 as a grand unified theory. We discuss the extra U(1) symmetries (beyond that in the standard SU(3) x SU(2) x U(1) model) that arise when E 6 is broken in such theories. These extra U(1)'s must lead to at least one extra neutral gauge boson, called Z', for which we give mass limits and branching ratios. Neutral current effects of this Z' and its direct production are discussed briefly. Finally, some signatures are noted of exotic fermions to which Z' can decay

  2. Quantum corrections to short folded superstring in AdS × S × M

    DEFF Research Database (Denmark)

    Beccaria, M.; Macorini, G.

    2013-01-01

    We consider integrable superstring theory on AdS × S × M where M = T or M = S × S with generic ratio of the radii of the two 3-spheres. We compute the one-loop energy of a short folded string spinning in AdS and rotating in S. The computation is performed by world-sheet small spin perturbation...... theory as well as by quantizing the classical algebraic curve characterizing the finite-gap equations. The two methods give equal results up to regularization contributions that are under control. One important byproduct of the calculation is the part of the energy which is due to the dressing phase...

  3. The low energy expansion of the one-loop type II superstring amplitude

    CERN Document Server

    Green, Michael B.; Green, Michael B.; Vanhove, Pierre

    2000-01-01

    The one-loop four-graviton amplitude in either of the type II superstring theories is expanded in powers of the external momenta up to and including terms of order s^4 log s R^4, where R^4 denotes a specific contraction of four linearized Weyl tensors and s is a Mandelstam invariant. Terms in this series are obtained by integrating powers of the two-dimensional scalar field theory propagator over the toroidal world-sheet as well as the moduli of the torus. The values of these coefficients match expectations based on duality relations between string theory and eleven-dimensional supergravity.

  4. Foundations of the AdS5 x S5 superstring: I

    International Nuclear Information System (INIS)

    Arutyunov, Gleb; Frolov, Sergey

    2009-01-01

    We review the recent advances towards finding the spectrum of the AdS 5 x S 5 superstring. We thoroughly explain the theoretical techniques which should be useful for the ultimate solution of the spectral problem. In certain cases our exposition is original and cannot be found in the existing literature. The present part I deals with foundations of classical string theory in AdS 5 x S 5 , light-cone perturbative quantization and the derivation of the exact light-cone world-sheet scattering matrix

  5. Y-formalism and b ghost in the non-minimal pure spinor formalism of superstrings

    International Nuclear Information System (INIS)

    Oda, Ichiro; Tonin, Mario

    2007-01-01

    We present the Y-formalism for the non-minimal pure spinor quantization of superstrings. In the framework of this formalism we compute, at the quantum level, the explicit form of the compound operators involved in the construction of the b ghost, their normal-ordering contributions and the relevant relations among them. We use these results to construct the quantum-mechanical b ghost in the non-minimal pure spinor formalism. Moreover we show that this non-minimal b ghost is cohomologically equivalent to the non-covariant b ghost

  6. Vacuum correlation functions for ghost superfields and multiloop amplitudes in the theory of closed superstrings

    International Nuclear Information System (INIS)

    Danilov, G.S.

    1995-01-01

    A new formalism for ghosts on complex (1 bar 1) supermanifolds of genus n > 1 is discussed in superstring theory. In this formalism, vacuum correlation functions for ghost superfields differ substantially from correlation functions discussed earlier. In particular, the new correlation functions do not have unphysical poles. Among other things, these correlation functions take into account contributions to partition functions from the phase space of modular forms and from zero modes of ghosts. The above correlation functions, obtained for all even spinor structures, can be used to evaluate partition functions from equations that are nothing but Ward identities. 21 refs

  7. TeV scale leptoquarks as a signature of standard-like superstring models

    International Nuclear Information System (INIS)

    Halyo, E.

    1993-12-01

    We show that there can be TeV scale scalar and fermionic leptoquarks with very weak Yukawa couplings in a generic standard-like superstring model. Leptoquark (down-like) quark mixing though present, is not large enough to violate the unitary bounds on the CKM matrix. The constraints on the leptoquark masses and couplings from flavor changing neutral currents are easily satisfied whereas those from baryon number violation may cause problems. The leptoquarks of the model are compared to the ones in the E 6 Calabi-Yau models. (author) 14 refs

  8. Radiotherapy-induced Early ECG Changes and Their Comparison with Echocardiography in Patients with Early-stage Breast Cancer.

    Science.gov (United States)

    Tuohinen, Suvi Sirkku; Keski-Pukkila, Konsta; Skyttä, Tanja; Huhtala, Heini; Virtanen, Vesa; Kellokumpu-Lehtinen, Pirkko-Liisa; Raatikainen, Pekka; Nikus, Kjell

    2018-04-01

    Early electrocardiogram (ECG) changes after breast cancer radiotherapy (RT) have been reported, but their characteristics and associated factors are largely unknown. This study aimed to explore early RT-induced ECG changes and to compare them with echocardiography changes. Sixty eligible patients with chemotherapy-naïve left-sided and 20 with right-sided breast cancer were evaluated with echocardiography, blood samples and ECG before and after RT. RT-induced ECG changes in the anterior leads. T-Wave changes were most frequent. T-Wave decline was associated independently with patient age (β=-0.245, p=0.005), mean heart radiation dose (β=1.252, p=0.001) and global systolic strain rate change (β=7.943, p=0.002). T-Wave inversion was associated independently with mean heart radiation dose (β=0.143, pECG changes were prevalent and associated with functional and structural changes in echocardiography. ECG could be used for post-RT cardiac screening. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. Lung Cancer Workshop XI: Tobacco-Induced Disease: Advances in Policy, Early Detection and Management.

    Science.gov (United States)

    Mulshine, James L; Avila, Rick; Yankelevitz, David; Baer, Thomas M; Estépar, Raul San Jose; Ambrose, Laurie Fenton; Aldigé, Carolyn R

    2015-05-01

    The Prevent Cancer Foundation Lung Cancer Workshop XI: Tobacco-Induced Disease: Advances in Policy, Early Detection and Management was held in New York, NY on May 16 and 17, 2014. The two goals of the Workshop were to define strategies to drive innovation in precompetitive quantitative research on the use of imaging to assess new therapies for management of early lung cancer and to discuss a process to implement a national program to provide high quality computed tomography imaging for lung cancer and other tobacco-induced disease. With the central importance of computed tomography imaging for both early detection and volumetric lung cancer assessment, strategic issues around the development of imaging and ensuring its quality are critical to ensure continued progress against this most lethal cancer.

  10. Radiation induced early delayed changes in mice brain: a 1h MRS and behavioral evaluation study

    International Nuclear Information System (INIS)

    Gupta, Mamta; Rana, Poonam; Haridas, Seenu; Manda, Kailash; Hemanth Kumar, B.S.; Khushu, Subash

    2014-01-01

    Radiation induced CNS injury can be classified as acute, early delayed and late delayed. Most of the studies suggest that acute injury is reversible whereas early delayed and late delayed injury is irreversible leading to metabolic and cognitive impairment. Extensive research has been carried out on cranial radiation induced early and late delayed changes, there are no reports on whole body radiation induced early and delayed changes. The present study was designed to observe early delayed effects of radiation during whole body radiation exposure. A total of 20 C57 male mice were divided in two groups of 10 animals each. One group was exposed to a dose of 5 Gy whole body radiation through Tele 60 Co irradiation facility with source operating at 2.496 Gy/min, while other group served as sham irradiated control. Behavioral and MR spectroscopy was carried out 3 months post irradiation. Behavioral parameters such as locomotor activity and working memory were evaluated first then followed by MR spectroscopy at 7T animal MRI system. For MRS, voxel was localised in the cortex-hippocampus region of mouse brain. MR spectra were acquired using PRESS sequence, FID was processed using LC model for quantitation. The data showed impaired cognitive functions and altered metabolite levels during early delayed phase of whole body radiation induced injury. In behavioural experiments, there was a significant impairment in the cognitive as well as exploratory functions at 3 months post irradiation in irradiated group as compared to controls. MRS results explained changes in mI, glutamine and glx levels in irradiated animals compared to controls. Altered mI level has been found to be associated with reduced cognitive abilities in many brain disorders including MCI and Alzheimer's disease. The findings of this study suggest that whole body radiation exposure may have long lasting effect on the cognitive performance. (author)

  11. One-loop mass shifts in O(32) open superstring theory

    International Nuclear Information System (INIS)

    Yamamoto, Hisashi.

    1987-08-01

    One-loop amplitudes of O(N) open superstring with emission of massive bosons are studied. Divergences appearing at λ = 0 (λ: the over-all Teichmueller parameter) are shown to be canceled if N = 32 just as in the massless case. We explicitly evaluate the two-point on-shell amplitudes for all the levels of bosons lying on the leading (m 2 = 2 l, J = l + 1, m:mass J:spin l:level number of an excited state) and the next-to-leading (m 2 = 2 l, J = l) Regge trajectories and observe that they are nonvanishing even at N = 32. This implies that O(32) open super-string one-loop amplitudes with massive bosons generally suffer from external-line divergences. Further the obtained expressions of on-shell self energies (mass shifts δm 2 (l)) seem to have nontrivial dependences on l (being not proportional to l), although mass degeneracies remain. This strongly suggests that the Regge trajectories form a set of parallel polygonal lines at one-loop level so that the mass shifts cannot be absorbed by the shift of the slope parameter. The divergences would have to be cured by the vertex operator renormalizations at every excited level. (author)

  12. Silica nanoparticles on front glass for efficiency enhancement in superstrate-type amorphous silicon solar cells

    Science.gov (United States)

    Das, Sonali; Banerjee, Chandan; Kundu, Avra; Dey, Prasenjit; Saha, Hiranmay; Datta, Swapan K.

    2013-10-01

    Antireflective coating on front glass of superstrate-type single junction amorphous silicon solar cells (SCs) has been applied using highly monodispersed and stable silica nanoparticles (NPs). The silica NPs having 300 nm diameter were synthesized by Stober technique where the size of the NPs was controlled by varying the alcohol medium. The synthesized silica NPs were analysed by dynamic light scattering technique and Fourier transform infrared spectroscopy. The NPs were spin coated on glass side of fluorinated tin oxide (SnO2: F) coated glass superstrate and optimization of the concentration of the colloidal solution, spin speed and number of coated layers was done to achieve minimum reflection characteristics. An estimation of the distribution of the NPs for different optimization parameters has been done using field-emission scanning electron microscopy. Subsequently, the transparent conducting oxide coated glass with the layer having the minimum reflectance is used for fabrication of amorphous silicon SC. Electrical analysis of the fabricated cell indicates an improvement of 6.5% in short-circuit current density from a reference of 12.40 mA cm-2 while the open circuit voltage and the fill factor remains unaltered. A realistic optical model has also been proposed to gain an insight into the system.

  13. Silica nanoparticles on front glass for efficiency enhancement in superstrate-type amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Das, Sonali; Kundu, Avra; Dey, Prasenjit; Saha, Hiranmay; Datta, Swapan K; Banerjee, Chandan

    2013-01-01

    Antireflective coating on front glass of superstrate-type single junction amorphous silicon solar cells (SCs) has been applied using highly monodispersed and stable silica nanoparticles (NPs). The silica NPs having 300 nm diameter were synthesized by Stober technique where the size of the NPs was controlled by varying the alcohol medium. The synthesized silica NPs were analysed by dynamic light scattering technique and Fourier transform infrared spectroscopy. The NPs were spin coated on glass side of fluorinated tin oxide (SnO 2 : F) coated glass superstrate and optimization of the concentration of the colloidal solution, spin speed and number of coated layers was done to achieve minimum reflection characteristics. An estimation of the distribution of the NPs for different optimization parameters has been done using field-emission scanning electron microscopy. Subsequently, the transparent conducting oxide coated glass with the layer having the minimum reflectance is used for fabrication of amorphous silicon SC. Electrical analysis of the fabricated cell indicates an improvement of 6.5% in short-circuit current density from a reference of 12.40 mA cm −2 while the open circuit voltage and the fill factor remains unaltered. A realistic optical model has also been proposed to gain an insight into the system. (paper)

  14. Repeated restraint stress exposure during early withdrawal accelerates incubation of cue-induced cocaine craving.

    Science.gov (United States)

    Glynn, Ryan M; Rosenkranz, J Amiel; Wolf, Marina E; Caccamise, Aaron; Shroff, Freya; Smith, Alyssa B; Loweth, Jessica A

    2018-01-01

    A major challenge for treating cocaine addiction is the propensity for abstinent users to relapse. Two important triggers for relapse are cues associated with prior drug use and stressful life events. To study their interaction in promoting relapse during abstinence, we used the incubation model of craving and relapse in which cue-induced drug seeking progressively intensifies ('incubates') during withdrawal from extended-access cocaine self-administration. We tested rats for cue-induced cocaine seeking on withdrawal day (WD) 1. Rats were then subjected to repeated restraint stress or control conditions (seven sessions held between WD6 and WD14). All rats were tested again for cue-induced cocaine seeking on WD15, 1 day after the last stress or control session. Although controls showed a time-dependent increase in cue-induced cocaine seeking (incubation), rats exposed to repeated stress in early withdrawal exhibited a more robust increase in seeking behavior between WD1 and WD15. In separate stressed and control rats, equivalent cocaine seeking was observed on WD48. These results indicate that repeated stress in early withdrawal accelerates incubation of cocaine craving, although craving plateaus at the same level were observed in controls. However, 1 month after the WD48 test, rats subjected to repeated stress in early withdrawal showed enhanced cue-induced cocaine seeking following acute (24 hours) food deprivation stress. Together, these data indicate that chronic stress exposure enhances the initial rate of incubation of craving during early withdrawal, resulting in increased vulnerability to cue-induced relapse during this period, and may lead to a persistent increase in vulnerability to the relapse-promoting effects of stress. © 2016 Society for the Study of Addiction.

  15. On $R^4$ terms and MHV amplitudes in N = 5,6 supergravity vacua of Type II superstrings

    CERN Document Server

    Bianchi, Massimo

    2011-01-01

    We compute one-loop threshold corrections to $R^4$ terms in N= 5,6 supergravity vacua of Type II superstrings. We then discuss non-perturbative corrections generated by asymmetric D-brane instantons. Finally we derive generating functions for MHV amplitudes at tree level in N = 5, 6 supergravities.

  16. Potentially large contributions to the muon anomalous magnetic moment from weak-isosinglet squarks in E6 superstring models

    International Nuclear Information System (INIS)

    Morris, D.A.

    1988-01-01

    We examine contributions to the anomalous magnetic moment of the muon from weak-isosinglet squarks found in E 6 superstring models. We find that such contributions are up to 2 orders of magnitude larger than those previously calculated and correspondingly require smaller Yukawa couplings in order to maintain agreement with the measured muon anomalous magnetic moment

  17. Reduction of radiation-induced early skin damage (mouse foot) by 0-(β-hydroxyaethyl)-rutoside

    International Nuclear Information System (INIS)

    Fritz-Niggli, H.; Froehlich, E.

    1980-01-01

    The effect of a bioflavonoid, 0-(β-hydroxyethyl)-rutoside (HR) on early radiation-induced skin damage was examined, using the mouse foot system; the response to radiation is not species specific and comparison with the clinical situation is therefore possible. The aim was to see whether HR, which is highly effective in protecting against late damage, is also able to reduce early effects. Early reactions were considered to be erythema, swelling and ulceration and occurring up to 30 days after irradiation. It was found that HR significantly reduces early damage, both after a single dose and after fractionated irradiation with low doses. A single pre-treatment dose of HR and pre-treatment together with 30 days post-treatment administration were both found to be effective. The protective effect became more marked with increasing radiation dose (single irradiation). Reduction of late effects is produced iptimally by an interval of 0.25 hours between application of HR and irradiation, and this is also true for early skin damage. The early effects are partly reversible, but there is possibly an interesting correlation between these and irreversible late effects (such as loss of toes); a similar mechanism, presumably affecting the vascular system, may therefore be postulated. The protective action of this well tolesated, highly effective substance, which apparently protects normal tissues from early and late injury, is discussed. (orig.) [de

  18. O(d, - Collapse/inflation in Colliding Superstring Waves

    Science.gov (United States)

    Bozza, V.; Veneziano, G.

    2002-12-01

    The present formulation of pre-big bang cosmology relies on the principle of asymptotic past triviality (APT)1 , i.e. on the assumption that, in its initial state, the Universe was in a low-curvature, small-coupling regime and was thus adequately described in terms of the low-energy, tree-level effective action of string theory. The early universe can thus be visualized as a chaotic superposition of massless waves, seen as excitations over a trivial Minkowski background. The superposition of these perturbations can eventually lead to the gravitational collapse of the interaction region. Measuring distances in string units, such a collapse can become an inflationary, dilaton-driven, expansion. According to the scenario depicted in Ref. 1, the collapse/inflation of sufficiently large regions could then evolve in a universe resembling our own. An explicit example of this phenomenon was given by Feinstein, Kunze & Vázquez-Mozo2 who studied a particular exact solution of the field equations describing the collision of two four-dimensional gravi-dilatonic plane waves. In our work3, including from the start the Kalb-Ramond Bμν 2-form in an arbitrary number D of space-time dimensions we recover their result in a more general O(d, d)-invariant formulation, allowing a full investigation of a wider class of solutions. The two plane waves are taken to travel in opposite directions along the same axis, so that, assuming plane symmetry, all fields are functions of the time coordinate and the common direction of propagation z. The problem is thus endowed with d = D - 2 abelian isometries, the action being invariant for translations along the transverse directions. In this situation, it is possible to write the action in terms of the restriction of the metric on the non-trivial coordinates (t, z), the shifted dilaton and a 2d × 2d matrix M built by combining the remaining components of the metric and the antisymmetric field...

  19. Potentially induced earthquakes during the early twentieth century in the Los Angeles Basin

    Science.gov (United States)

    Hough, Susan E.; Page, Morgan T.

    2016-01-01

    Recent studies have presented evidence that early to mid‐twentieth‐century earthquakes in Oklahoma and Texas were likely induced by fossil fuel production and/or injection of wastewater (Hough and Page, 2015; Frohlich et al., 2016). Considering seismicity from 1935 onward, Hauksson et al. (2015) concluded that there is no evidence for significant induced activity in the greater Los Angeles region between 1935 and the present. To explore a possible association between earthquakes prior to 1935 and oil and gas production, we first revisit the historical catalog and then review contemporary oil industry activities. Although early industry activities did not induce large numbers of earthquakes, we present evidence for an association between the initial oil boom in the greater Los Angeles area and earthquakes between 1915 and 1932, including the damaging 22 June 1920 Inglewood and 8 July 1929 Whittier earthquakes. We further consider whether the 1933 Mw 6.4 Long Beach earthquake might have been induced, and show some evidence that points to a causative relationship between the earthquake and activities in the Huntington Beach oil field. The hypothesis that the Long Beach earthquake was either induced or triggered by an foreshock cannot be ruled out. Our results suggest that significant earthquakes in southern California during the early twentieth century might have been associated with industry practices that are no longer employed (i.e., production without water reinjection), and do not necessarily imply a high likelihood of induced earthquakes at the present time.

  20. Management of early pregnancy failure and induced abortion by family medicine educators.

    Science.gov (United States)

    Herbitter, Cara; Bennett, Ariana; Schubert, Finn D; Bennett, Ian M; Gold, Marji

    2013-01-01

    Reproductive health care, including treatment of early pregnancy failure (EPF) and induced abortion, is an integral part of patient-centered care provided by family physicians, but data suggest that comprehensive training is not widely available to family medicine residents. The purpose of this study was to assess EPF and induced abortion management practices and attitudes of family medicine physician educators throughout the United States and Canada. These data were collected as part of a cross-sectional survey conducted by the Council of Academic Family Medicine Educational Research Alliance that was distributed via E-mail to 3152 practicing physician members of Council of Academic Family Medicine organizations. The vast majority of respondents (88.2%) had treated EPF, whereas few respondents (15.3%) had provided induced medication or aspiration abortions. Of those who had treated EPF, most had offered medication management (72.7%), whereas a minority had provided aspiration management (16.4%). Almost all respondents (95%) agreed that EPF management is within the scope of family medicine, and nearly three-quarters (73.2%) agreed that early induced abortion is within the scope of family medicine. Our findings suggest that family physician educators are more experienced with EPF management than elective abortion. Given the overlap of skills needed for provision of these services, there is the potential to increase the number of family physician faculty members providing induced abortions.

  1. Tn5-induced pBS286 plasmid mutations blocking early stages of napthalene oxidation

    International Nuclear Information System (INIS)

    Kosheleva, I.A.; Tsoi, T.V.; Ivashina, T.V.; Selifonov, S.A.; Starovoitov, I.I.; Boronin, A.M.

    1988-01-01

    The authors present data on the further analysis of the structural and functional organization of the nah region of plasmid pBS286 controlling the constitutive oxidation of naphthalene by Pseudomonas putida cells. They have studied Tn5-induced mutations blocking early stages of naphthalene oxidation. They present and discuss data providing evidence that, in contrast to plasmid NAH7, the mechanism of regulation of the nahl operon of plasmid NPL-1, the parent plasmid of plasmid pBS286, with inducible synthesis of naphthalene dioxygenase can include elements of a negative control with participation of the regulatory locus R, located proximal to the structural nah genes and closely linked to or overlapped by the inverted control DNA segment (4.2 kb). They also present data on the possibility of regulation of the activity of the catechol-splitting meta-pathway genes with the participation of products of early stages of naphthalene oxidation

  2. Wilson-Polyakov loops for critical strings and superstrings at finite temperature

    International Nuclear Information System (INIS)

    Green, M.B.

    1992-01-01

    An open string with end-points fixed at spatial separation L is a string theory analogue of the static quark-antiquark system in quenched QCD. Folowing a review of the quantum mechanics of this system in critical bosonic string theory the partition function at finite β (the inverse temperature) for fixed end-point open strings is discussed. This is related by a conformal transformation ('world-sheet duality') to the correlation function of two closed strings fixed at distinct spatial points (a string theory analogue of two Wilson-Polyakov loops). Temperature duality (β → β' = 4π 2 /β) relates this correlation function, in turn, to the finite-temperature Green function for a closed strong propagating between initial and final states that are at distinct (euclidean) space-time points. In addition, spatial duality relates the fixed end-point open string to the familiar open string with free end-points. A generalization to fixed end-points superstrings is suggested, in which the superalgebra may be viewed as the spatial dual of the usual open-string superalgebra. At zero temperature world-sheet duality relates the partition function of supersymmetric fixed end-point open strings to the correlation function of point-like closed-string states. These couple to combinations of the scalar and pseudoscalar states of a type-2b superstring superfield. At finite temperature supersymmetry is broken and this correlation function involves the propagation of non-supersymmetric states with non-zero winding numbers (which formally include a tachyon at temperatures above the Hagedorn transition). Temperature duality again relates the partition function to the finite-temperature Green function describing the propagator for point-like closed-string states of the dual theory, in which supersymmetry is broken. The singularity that arises in the critical bosonic theory as L is reduced below L = 2 π√α' is absent in the superstring and the static potential is well defined for all

  3. Lithium prevents long-term neural and behavioral pathology induced by early alcohol exposure.

    Science.gov (United States)

    Sadrian, B; Subbanna, S; Wilson, D A; Basavarajappa, B S; Saito, M

    2012-03-29

    Fetal alcohol exposure can cause developmental defects in offspring known as fetal alcohol spectrum disorder (FASD). FASD symptoms range from obvious facial deformities to changes in neuroanatomy and neurophysiology that disrupt normal brain function and behavior. Ethanol exposure at postnatal day 7 in C57BL/6 mice induces neuronal cell death and long-lasting neurobehavioral dysfunction. Previous work has demonstrated that early ethanol exposure impairs spatial memory task performance into adulthood and perturbs local and interregional brain circuit integrity in the olfacto-hippocampal pathway. Here we pursue these findings to examine whether lithium prevents anatomical, neurophysiological, and behavioral pathologies that result from early ethanol exposure. Lithium has neuroprotective properties that have been shown to prevent ethanol-induced apoptosis. Here we show that mice co-treated with lithium on the same day as ethanol exposure exhibit dramatically reduced acute neurodegeneration in the hippocampus and retain hippocampal-dependent spatial memory as adults. Lithium co-treatment also blocked ethanol-induced disruption in synaptic plasticity in slice recordings of hippocampal CA1 in the adult mouse brain. Moreover, long-lasting dysfunctions caused by ethanol in olfacto-hippocampal networks, including sensory-evoked oscillations and resting state coherence, were prevented in mice co-treated with lithium. Together, these results provide behavioral and physiological evidence that lithium is capable of preventing or reducing immediate and long-term deleterious consequences of early ethanol exposure on brain function. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    International Nuclear Information System (INIS)

    Das, Suvarthi; Kumar, Ashutosh; Seth, Ratanesh Kumar; Tokar, Erik J.; Kadiiska, Maria B.; Waalkes, Michael P.; Mason, Ronald P.; Chatterjee, Saurabh

    2013-01-01

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates protein

  5. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    Energy Technology Data Exchange (ETDEWEB)

    Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Seth, Ratanesh Kumar [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Tokar, Erik J. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Waalkes, Michael P. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Mason, Ronald P. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

    2013-06-15

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates

  6. Retracing the phenomenology of the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Rizos, J.; Tamvakis, K. (Ioannina Univ. (Greece). Dept. of Physics)

    1990-11-22

    We study in detail gauge symmetry breaking in the SU(5)xU(1)'xU(1){sup 4}xSO(10)xSO(6) superstring model, solving the D- and F-flatness conditions and taking into account quartic and quintic superpotential terms. We find that, to this order, the model describes two massive generations of quarks and leptons as well as a massless generation expected to receive naturally suppressed masses from higher order non-renormalizable terms. We show that D-flatness restricts the number of massless isodoublets to four. We also extract an inequality relating the top quark mass to M{sub W}. (orig.).

  7. Wess-Zumino term for the AdS superstring and generalized Inoenue-Wigner contraction

    International Nuclear Information System (INIS)

    Hatsuda, Machiko; Sakaguchi, Makoto

    2003-01-01

    We examine a Wess-Zumino term, written in a form of bilinear in superinvariant currents, for a superstring in anti-de Sitter (AdS) space, and derive a procedure for obtaining the correct flat limit. The standard Inoenue-Wigner contraction does not give the correct flat limit but, rather, gives zero. This erroneous result originates from the fact that the fermionic metric of the super-Poincare group is degenerate. We propose a generalization of the Inoenue-Wigner contraction from which a 'nondegenerate' super-Poincare group is derived from the super-AdS group. For this reason, this contraction gives the correct flat limit of this Wess-Zumino term. We also discuss the M-algebra obtained using this generalized Inoenue-Wigner contraction from osp(1|32). (author)

  8. Multiloop amplitudes and vanishing theorems using the pure spinor formalism for the superstring

    International Nuclear Information System (INIS)

    Berkovits, Nathan

    2004-01-01

    A ten-dimensional super-Poincare covariant formalism for the superstring was recently developed which involves a BRST operator constructed from superspace matter variables and a pure spinor ghost variable. A super-Poincare covariant prescription was defined for computing tree amplitudes and was shown to coincide with the standard RNS prescription. In this paper, picture-changing operators are used to define functional integration over the pure spinor ghosts and to construct a suitable b ghost. A super-Poincare covariant prescription is then given for the computation of N-point multiloop amplitudes. One can easily prove that massless N-point multiloop amplitudes vanish for N 4 terms in the effective action receive no perturbative contributions above one loop. (author)

  9. Simplifying superstring and D-brane actions in AdS4 x CP3 superbackground

    International Nuclear Information System (INIS)

    Grassi, Pietro Antonio; Sorokin, Dmitri; Wulff, Linus

    2009-01-01

    By making an appropriate choice for gauge fixing kappa-symmetry we obtain a relatively simple form of the actions for a D = 11 superparticle in AdS 4 x S 7 /Z k , and for a D0-brane, fundamental string and D2-branes in the AdS 4 x CP 3 superbackground. They can be used to study various problems of string theory and the AdS 4 /CFT 3 correspondence, especially in regions of the theory which are not reachable by the OSp(6|4)/U(3) x SO(1,3) supercoset sigma-model. In particular, we present a simple form of the gauge-fixed superstring action in AdS 4 x CP 3 and briefly discuss issues of its T-dualization.

  10. Infrared behavior of closed superstrings in strong magnetic and gravitational fields

    International Nuclear Information System (INIS)

    Kiritsis, E.; Kounnas, C.

    1995-01-01

    A large class of four-dimensional supersymmetric ground states of closed superstrings with a non-zero mass gap are constructed. For such ground states we turn on chromo-magnetic fields as well as curvature. The exact spectrum as function of the chromo-magnetic fields and curvature is derived. We examine the behavior of the spectrum, and find that there is a maximal value for the magnetic field H max similar M planck 2 . At this value all states that couple to the magnetic field become infinitely massive and decouple. We also find tachyonic instabilities for strong background fields of the order O (μM planck ) where μ is the mass gap of the theory. Unlike the field theory case, we find that such ground states become stable again for magnetic fields of the order O (M 2 planck ). The implications of these results are discussed. (orig.)

  11. Symplectic geometry of field theories and covariant quantization of superstrings and superparticles

    International Nuclear Information System (INIS)

    Crnkovic, C.

    1987-01-01

    A detailed development of the symplectic geometry formalism for a general Lagrangian field theory is presented. Special attention is paid to the theories with constraints and/or gauge degrees of freedom. Special cases of Yang-Mills theory, general relativity and Witten's string field theory are studied and the generators of (super-) Poincare transformations are derived using their respective symplectic forms. The formalism extends naturally to theories formulated in the superspace. The second part of the thesis deals with issues in covariant quantization. By studying the symplectic geometry of the Green-Schwarz covariant superstring action, we elucidate some aspects of its covariant quantization. We derive the on-shell gauge-fixed action and the equations of motion for all the fields. Finally, turning to Siegel's version of the superparticle action, we perform its BRST quantization

  12. Symmetry breaking in superstring theories: applications in cosmology and particle physics

    International Nuclear Information System (INIS)

    Catelin-Julien, T.

    2008-10-01

    This thesis is devoted to the study of some applications of superstring theory in cosmology and in particle physics. The unifying principle of our work is the stringy spontaneous (super)symmetry breaking mechanism. Our manuscript starts with a general overview of string theory, where the emphasis is put on the aspects that will be important throughout our work. We introduce then our first work, in which we exhibit a new symmetry of the vacua of N = 1 heterotic string theory, exchanging the vectorial and spinorial representations of the grand unified gauge group. In a second part, we consider stringy cosmological evolutions, at non-zero temperature and in the presence of a supersymmetry breaking scale. We also give arguments for a stabilization of the compactification moduli. (author)

  13. Higgs boson production via Z, W bosons and toponium in the E6 superstring model

    International Nuclear Information System (INIS)

    Barger, V.; Whisnant, K.

    1988-01-01

    The authors examine the production of light Higgs bosons associated with electroweak symmetry-breaking in an E 6 superstring model in Z ω HZ * decays, in e + e - annihilation and in toponium decays. They find that the couplings of the lightest scalar Higgs boson H 1 0 in these models are very similar to those of the standard Higgs boson unless the pseudoscalar P 0 in the model has mass ≤ M z . Possible new modes for Higgs boson production not found in the standard model are presented. The authors give simple analytic expressions for the Higgs boson masses and mixing angles in the limit that the extra Z' gauge boson is heavy which clearly shows the production mechanisms that are favored for a given set of model parameters

  14. Low-energy consequences of superstring-inspired models with intermediate-mass scales

    International Nuclear Information System (INIS)

    Gabbiani, F.

    1987-01-01

    The phenomenological consequences of implementing intermediate-mass scales in E 6 superstring-inspired models are discussed. Starting from a suitable Calabi-Yau compactification with b 1,1 >1, one gets, after Hosotani breaking, the rank r=5 gauge group SU(3) C x SU(2) L x U(1) Y x U(1) E , that is broken at an intermediate-mass scale down to the standard-model group. The analysis of both the intermediate and the electroweak breaking is performed in the two cases Λ c = M x and Λ c x , where Λ c is the scale at which the hidden sector gauginos condensate. It is performed quantitatively the minimization of the low-energy effective potential and the renormalization group analysis, yielding a viable set of mass spectra and confirming the reliability of the intermediate-breaking scheme

  15. Compactification and inflation in the superstring theory from the condensation of gravitino pairs

    Science.gov (United States)

    Pollock, M. D.

    1987-12-01

    We discuss the possibility that inflation can occur in the E8×E8' heterotic superstring theory, if there is a pair condensation of the gravitino field ψA and also of the Majorana-Weyl spinor λ, as suggested by the Helayël-Neto and Smith. In the absence of a condensation of the anti-symmetric tensor field HMNP, then the associated potential V(θ,φ) is bounded from below and independent of the dilaton field φ. It can be made to vanish at the minimum, where the compactification scale θ is fixed. Alternatively, a small cosmological constant may remain (ultimately to be cancelled by radiative corrections at the lower energy scale of the gaugino condensation), which could in principle lead to inflation. Present address: Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400 005, India.

  16. Pure gauge configurations and solutions to fermionic superstring field theory equations of motion

    International Nuclear Information System (INIS)

    Aref'eva, I Ya; Gorbachev, R V; Medvedev, P B

    2009-01-01

    Recent results on solutions to the equation of motion of the cubic fermionic string field theory and an equivalence of nonpolynomial and cubic string field theory are discussed. To have the possibility of dealing with both GSO(+) and GSO(-) sectors in the uniform way, a matrix formulation for the NS fermionic SFT is used. In constructions of analytical solutions to open-string field theories truncated pure gauge configurations parametrized by wedge states play an essential role. The matrix form of this parametrization for NS fermionic SFT is presented. Using the cubic open superstring field theory as an example we demonstrate explicitly that for the large parameter of the perturbation expansion these truncated pure gauge configurations give divergent contributions to the equations of motion on the subspace of the wedge states. The perturbation expansion is corrected by adding extra terms that are just those necessary for the equation of motion contracted with the solution itself to be satisfied.

  17. More comments on superstring interactions in the pp-wave background

    International Nuclear Information System (INIS)

    Pankiewicz, Ari

    2002-01-01

    We reconsider light-cone superstring field theory on the maximally supersymmetric pp-wave background. We find that the results for the fermionic Neumann matrices given so far in the literature are incomplete and verify our expressions by relating them to the bosonic Neumann matrices and proving several non-trivial consistency conditions among them, as for example the generalization of a flat space factorization theorem for the bosonic Neumann matrices. We also study the bosonic and fermionic constituents of the prefactor and point out a subtlety in the relation between continuum and oscillator basis expressions. We give a proof that a recent proposal to use a different fermionic zero-mode vertex, leads to inconsistencies not visible in supergravity. (author)

  18. Membrane remodeling, an early event in benzo[α]pyrene-induced apoptosis

    International Nuclear Information System (INIS)

    Tekpli, Xavier; Rissel, Mary; Huc, Laurence; Catheline, Daniel; Sergent, Odile; Rioux, Vincent; Legrand, Philippe; Holme, Jorn A.; Dimanche-Boitrel, Marie-Therese; Lagadic-Gossmann, Dominique

    2010-01-01

    Benzo[α]pyrene (B[α]P) often serves as a model for mutagenic and carcinogenic polycyclic aromatic hydrocarbons (PAHs). Our previous work suggested a role of membrane fluidity in B[α]P-induced apoptotic process. In this study, we report that B[α]P modifies the composition of cholesterol-rich microdomains (lipid rafts) in rat liver F258 epithelial cells. The cellular distribution of the ganglioside-GM1 was markedly changed following B[α]P exposure. B[α]P also modified fatty acid composition and decreased the cholesterol content of cholesterol-rich microdomains. B[α]P-induced depletion of cholesterol in lipid rafts was linked to a reduced expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase). Aryl hydrocarbon receptor (AhR) and B[α]P-related H 2 O 2 formation were involved in the reduced expression of HMG-CoA reductase and in the remodeling of membrane microdomains. The B[α]P-induced membrane remodeling resulted in an intracellular alkalinization observed during the early phase of apoptosis. In conclusion, B[α]P altered the composition of plasma membrane microstructures through AhR and H 2 O 2 dependent-regulation of lipid biosynthesis. In F258 cells, the B[α]P-induced membrane remodeling was identified as an early apoptotic event leading to an intracellular alkalinization.

  19. Abnormal-induced theta activity supports early directed-attention network deficits in progressive MCI.

    Science.gov (United States)

    Deiber, Marie-Pierre; Ibañez, Vicente; Missonnier, Pascal; Herrmann, François; Fazio-Costa, Lara; Gold, Gabriel; Giannakopoulos, Panteleimon

    2009-09-01

    The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.

  20. Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bakkal, B.H. [Department of Radiation Oncology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Gultekin, F.A. [Department of General Surgery, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Guven, B. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Turkcu, U.O. [Mugla School of Health Sciences, Mugla Sitki Kocman University, Mugla (Turkey); Bektas, S. [Department of Pathology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Can, M. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey)

    2013-09-27

    Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

  1. Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

    International Nuclear Information System (INIS)

    Bakkal, B.H.; Gultekin, F.A.; Guven, B.; Turkcu, U.O.; Bektas, S.; Can, M.

    2013-01-01

    Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage

  2. Homologous series of induced early mutants in Indica rice. Pt.3: The relationship between the induction of homologous series of early mutants and its different pedigree

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2002-01-01

    The percentage of homologous series of early mutants (PHSEM) induced by irradiation was closely related to its pedigree. This study showed that PHSEM for varieties with the same pedigree were similar, and there were three different level of dominance (high, low and normal) in the homologous series induced from different pedigree. The PHSEM for varieties derived form distant-relative-parents were higher than that derived from close-relative-parents. There was the dominance pedigree for the induction of homologous series of early mutants. IR8(Peta x DGWG), IR127 (Cpslo x Sigadis) and IR24 (IR8 x IR127) were dominant pedigree, and varieties derived from them could be easily induced the homologous series of early mutants

  3. Regulation of radiation-induced apoptosis by early growth response-1 gene in solid tumors

    International Nuclear Information System (INIS)

    Ahmed, M.

    2003-01-01

    Ionizing radiation exposure is associated with activation of certain immediate-early genes that function as transcription factors. These include members of jun or fos and early growth response (EGR) gene families. In particular, the functional role of EGR-1 in radiation-induced signaling is pivotal since the promoter of EGR-1 contains radiation-inducible CArG DNA sequences. The Egr-1 gene belongs to a family of Egr genes that includes EGR-2, EGR-3, EGR-4, EGR-α and the tumor suppressor, Wilms' tumor gene product, WT1. The Egr-1 gene product, EGR-1, is a nuclear protein that contains three zinc fingers of the C 2 H 2 subtype. The EGR-1 GC-rich consensus target sequence, 5'-GCGT/GGGGCG-3' or 5'-TCCT/ACCTCCTCC-3', has been identified in the promoter regions of transcription factors, growth factors, receptors, cell cycle regulators and pro-apoptotic genes. The gene targets mediated by Egr-1 in response to ionizing radiation include TNF-α , p53, Rb and Bax, all these are effectors of apoptosis. Based on these targets, Egr-1 is a pivotal gene that initiates early signal transduction events in response to ionizing radiation leading to either growth arrest or cell death in tumor cells. There are two potential application of Egr-1 gene in therapy of cancer. First, the Egr-1 promoter contains information for appropriate spatial and temporal expression in-vivo that can be regulated by ionizing radiation to control transcription of genes that have pro-apoptotic and suicidal function. Secondly, EGR-1 protein can eliminate 'induced-radiation resistance' by inhibiting the functions of radiation-induced pro-survival genes (NFκB activity and bcl-2 expression) and activate pro-apoptotic genes (such as bax) to confer a significant radio-sensitizing effect. Together, the reported findings from my laboratory demonstrate clearly that EGR-1 is an early central gene that confers radiation sensitivity and its pro-apoptotic functions are synergized by abrogation of induced radiation

  4. One-point functions of non-SUSY operators at arbitrary genus in a matrix model for type IIA superstrings

    International Nuclear Information System (INIS)

    Kuroki, Tsunehide; Sugino, Fumihiko

    2017-01-01

    In the previous paper, the authors pointed out correspondence between a supersymmetric double-well matrix model and two-dimensional type IIA superstring theory on a Ramond–Ramond background from the viewpoint of symmetry and spectrum. This was confirmed by agreement between planar correlation functions in the matrix model and tree-level amplitudes in the superstring theory. In order to investigate the correspondence further, in this paper we compute correlation functions to all order of genus expansion in the double scaling limit of the matrix model. One-point functions of operators protected by supersymmetry terminate at some finite order, whereas those of unprotected operators yield non-Borel summable series. The behavior of the latter is characteristic in string perturbation series, providing further evidence that the matrix model describes a string theory. Moreover, instanton corrections to the planar one-point functions are also computed, and universal logarithmic scaling behavior is found for non-supersymmetric operators.

  5. One-point functions of non-SUSY operators at arbitrary genus in a matrix model for type IIA superstrings

    Energy Technology Data Exchange (ETDEWEB)

    Kuroki, Tsunehide, E-mail: kuroki@dg.kagawa-nct.ac.jp [General Eduction, National Institute of Technology, Kagawa College, 551 Kohda, Takuma-cho, Mitoyo, Kagawa 769-1192 (Japan); Sugino, Fumihiko, E-mail: fusugino@gmail.com [Okayama Institute for Quantum Physics, Furugyocho 1-7-36, Naka-ku, Okayama 703-8278 (Japan)

    2017-06-15

    In the previous paper, the authors pointed out correspondence between a supersymmetric double-well matrix model and two-dimensional type IIA superstring theory on a Ramond–Ramond background from the viewpoint of symmetry and spectrum. This was confirmed by agreement between planar correlation functions in the matrix model and tree-level amplitudes in the superstring theory. In order to investigate the correspondence further, in this paper we compute correlation functions to all order of genus expansion in the double scaling limit of the matrix model. One-point functions of operators protected by supersymmetry terminate at some finite order, whereas those of unprotected operators yield non-Borel summable series. The behavior of the latter is characteristic in string perturbation series, providing further evidence that the matrix model describes a string theory. Moreover, instanton corrections to the planar one-point functions are also computed, and universal logarithmic scaling behavior is found for non-supersymmetric operators.

  6. Aortic VCAM-1: an early marker of vascular inflammation in collagen-induced arthritis.

    Science.gov (United States)

    Denys, Anne; Clavel, Gaëlle; Lemeiter, Delphine; Schischmanoff, Olivier; Boissier, Marie-Christophe; Semerano, Luca

    2016-05-01

    Cardiovascular disease (CVD) is a major cause of morbidity and mortality in rheumatoid arthritis (RA). There are limited experimental data on vascular involvement in arthritis models. To study the link between CVD and inflammation in RA, we developed a model of vascular dysfunction and articular inflammation by collagen-induced arthritis (CIA) in C57Bl/6 (B6) mice. We studied the expression of vascular inflammatory markers in CIA with and without concomitant hyperlipidic diet (HD). Collagen-induced arthritis was induced with intradermal injection of chicken type-II collagen followed by a boost 21 days later. Mice with and without CIA were fed a standard diet or an HD for 12 weeks starting from the day of the boost. Arthritis severity was evaluated with a validated clinical score. Aortic mRNA levels of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS) and interleukin-17 were analysed by quantitative RT-PCR. Vascular cell adhesion molecule-1 localization in the aortic sinus was determined by immunohistochemistry. Atherosclerotic plaque presence was assessed in aortas. Collagen-induced arthritis was associated with increased expression of VCAM-1, independent of diet. VCAM-1 overexpression was detectable as early as 4 weeks after collagen immunization and persisted after 15 weeks. The HD induced atheroma plaque formation and aortic iNOS expression regardless of CIA. Concomitant CIA and HD had no additive effect on atheroma or VCAM-1 or iNOS expression. CIA and an HD diet induced a distinct and independent expression of large-vessel inflammation markers in B6 mice. This model may be relevant for the study of CVD in RA. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. Clinical features and hormonal profiles of cloprostenol-induced early abortions in heifers monitored by ultrasonography

    Directory of Open Access Journals (Sweden)

    Beckers Jean-François

    2006-11-01

    Full Text Available Abstract Background The present study describes the clinical features and plasma profiles of bovine pregnancy-associated glycoprotein 1 (bPAG1, the main metabolite of prostaglandin F2α (PG metabolite and progesterone (P4 in heifers in which early abortions were induced. Methods Early abortions were induced in four heifers with cloprostenol and monitored by ultrasonography. Blood samples were collected and the plasma were analyzed for bPAG 1, P4 and PG metabolite. Results The foetal heartbeat rates varied from 170–186 beats per minute for all foetuses up to the date of cloprostenol treatment. Foetal death was confirmed within two days after cloprostenol treatment. Prior to cloprostenol injection, blood plasma concentrations of bPAG1, PG metabolite and P4 varied from 8.4 – 40.0 ng/mL, 158 – 275 pmol/L and 20.7 – 46.9 nmol/L, respectively. After the foetus expelled, the plasma level of bPAG1 began to decrease but the decrease was small and gradual. The estimated half-life of bPAG1 was 1.8 – 6.6 days. The plasma level of the PG metabolite started to have short lasting peaks (above 300 pmol/L within three hours after cloprostenol treatment. The plasma concentrations of P4 dropped sharply to less than 4 nmol/L after 24 hours of cloprostenol injection. Conclusion The current findings indicated that after early closprostenol-induced foetal death, the plasma concentration of bPAG1 decreased gradually and showed a tendency of variation with the stages of pregnancy.

  8. Topics in N = 1 supergravity in four dimensions and superstring effective field theories beyond tree-level

    International Nuclear Information System (INIS)

    Saririan, K.

    1997-05-01

    In this thesis, the author presents some works in the direction of studying quantum effects in locally supersymmetric effective field theories that appear in the low energy limit of superstring theory. After reviewing the Kaehler covariant formulation of supergravity, he shows the calculation of the divergent one-loop contribution to the effective boson Lagrangian for supergravity, including the Yang-Mills sector and the helicity-odd operators that arise from integration over fermion fields. The only restriction is on the Yang-Mills kinetic energy normalization function, which is taken diagonal in gauge indices, as in models obtained from superstrings. He then presents the full result for the divergent one-loop contribution to the effective boson Lagrangian for supergravity coupled to chiral and Yang-Mills supermultiplets. He also considers the specific case of dilaton couplings in effective supergravity Lagrangians from superstrings, for which the one-loop result is considerably simplified. He studies gaugino condensation in the presence of an intermediate mass scale in the hidden sector. S-duality is imposed as an approximate symmetry of the effective supergravity theory. Furthermore, the author includes in the Kaehler potential the renormalization of the gauge coupling and the one-loop threshold corrections at the intermediate scale. It is shown that confinement is indeed achieved. Furthermore, a new running behavior of the dilaton arises which he attributes to S-duality. He also discusses the effects of the intermediate scale, and possible phenomenological implications of this model

  9. Early atherosclerosis and vascular inflammation in mice with diet-induced type 2 diabetes

    DEFF Research Database (Denmark)

    Bartels, E D; Bang, C A; Nielsen, L B

    2009-01-01

    and the median lesion area was 8.0 times higher than in fat-fed wild-type mice (P = 0.001). Intracellular adhesion molecule-1 staining of the aortic endothelium was most pronounced in the fat-fed apoB transgenic mice. CONCLUSIONS: Our findings suggest that diet-induced type 2 diabetes causes early......BACKGROUND: Obesity and type 2 diabetes increase the risk of atherosclerosis. It is unknown to what extent this reflects direct effects on the arterial wall or secondary effects of hyperlipidaemia. MATERIALS AND METHODS: The effect of obesity and type 2 diabetes on the development...

  10. The Evaluation of Melatonin Effect Against The Early Effect of Ionizing Radiation Induced Lung Injury

    Directory of Open Access Journals (Sweden)

    raziyeh tahamtan

    2014-06-01

    Results: the results indicated that radiation increases the collapse and fibrosis and cause the abundance of macrophage compared to control group (p<0.05. Oral administration of melatonin before radiation therapy significantly increased the lymphocyte and macrophage frequency (p<0.001 and decreased the RBC (p<0.05 frequency compared to the radiation group. Conclusion: According to the results, melatonin can prevent early damages in irradiated lungs. Free radicals cause cytotoxicity and melatonin can directly decrease the radiation induced cell damages by converting the free radicals to non- toxic compounds and also through the activation of the major antioxidant enzymes.

  11. Optical-fiber-based laser-induced breakdown spectroscopy for detection of early caries

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-06-01

    A laser-induced breakdown spectroscopy (LIBS) system targeting for the in vivo analysis of tooth enamel is described. The system is planned to enable real-time analysis of teeth during laser dental treatment by utilizing a hollow optical fiber that transmits both Q-switched Nd:YAG laser light for LIBS and infrared Er:YAG laser light for tooth ablation. The sensitivity of caries detection was substantially improved by expanding the spectral region under analysis to ultraviolet (UV) light and by focusing on emission peaks of Zn in the UV region. Subsequently, early caries were distinguished from healthy teeth with accuracy rates above 80% in vitro.

  12. Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

    International Nuclear Information System (INIS)

    Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.; Bilimoria, Shaen L.

    2008-01-01

    Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV XS ; 400 μg/ml), UV-irradiated virus (CIV UV ; 10 μg/ml) and CVPE (CIV protein extract; 10 μg/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 μg/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i. CIV UV or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV UV particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV UV , CIV XS or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae, apoptosis: (i) requires entry and

  13. Early biomarkers and potential mediators of ventilation-induced lung injury in very preterm lambs

    Directory of Open Access Journals (Sweden)

    Davis Peter G

    2009-03-01

    Full Text Available Abstract Background Bronchopulmonary dysplasia (BPD is closely associated with ventilator-induced lung injury (VILI in very preterm infants. The greatest risk of VILI may be in the immediate period after birth, when the lungs are surfactant deficient, still partially filled with liquid and not uniformly aerated. However, there have been very few studies that have examined this immediate post-birth period and identified the initial injury-related pathways that are activated. We aimed to determine if the early response genes; connective tissue growth factor (CTGF, cysteine rich-61 (CYR61 and early growth response 1 (EGR1, were rapidly induced by VILI in preterm lambs and whether ventilation with different tidal volumes caused different inflammatory cytokine and early response gene expression. Methods To identify early markers of VILI, preterm lambs (132 d gestational age; GA, term ~147 d were resuscitated with an injurious ventilation strategy (VT 20 mL/kg for 15 min then gently ventilated (5 mL/kg for 15, 30, 60 or 120 min (n = 4 in each. To determine if early response genes and inflammatory cytokines were differentially regulated by different ventilation strategies, separate groups of preterm lambs (125 d GA; n = 5 in each were ventilated from birth with a VT of 5 (VG5 or 10 mL/kg (VG10 for 135 minutes. Lung gene expression levels were compared to levels prior to ventilation in age-matched control fetuses. Results CTGF, CYR61 and EGR1 lung mRNA levels were increased ~25, 50 and 120-fold respectively (p CTGF, CYR61, EGR1, IL1-β, IL-6 and IL-8 mRNA levels compared to control levels. CTGF, CYR61, IL-6 and IL-8 expression levels were higher in VG10 than VG5 lambs; although only the IL-6 and CYR61 mRNA levels reached significance. Conclusion CTGF, CYR61 and EGR1 may be novel early markers of lung injury and mechanical ventilation from birth using relatively low tidal volumes may be less injurious than using higher tidal volumes.

  14. Early Mars serpentinization-derived CH4 reservoirs, H2 induced warming and paleopressure evolution

    Science.gov (United States)

    Lasue, J.; Chassefiere, E.; Langlais, B.; Quesnel, Y.

    2016-12-01

    CH4 has been observed on Mars both by remote sensing and in situ during the past 15 years. Early Mars serpentinization is one possible abiotic mechanism that could not only produce methane, but also explain the observed Martian remanent magnetic field. Assuming a cold early Mars, a cryosphere could trap such CH4 as clathrates in stable form at depth. We recently estimated the maximum storage capacity of such clathrate layer to be about 2x1019 to 2x1020 moles of methane. Such reservoirs may be stable or unstable, depending on many factors that are poorly constrained: major and sudden geological events such as the Tharsis bulge formation, the Hellas impact or the martian polar wander, could have destabilized the clathrates early in the history of the planet and released large quantities of gas in the atmosphere. Here we estimate the associated amounts of serpentinization-derived CH4 stored in the cryosphere that have been released to the atmosphere at the end of the Noachian and the beginning of the Hesperian. Due to rapid clathrate dissociation and photochemical conversion of CH4 to H2, these episodes of massive CH4 release may have resulted in transient H2-rich atmospheres, at typical levels of 10-20% in a background 1-2 bar CO2 atmosphere. We propose that the early Mars cryosphere had a sufficient CH4 storage capacity to have maintained H2-rich transient atmospheres during a total time period up to several Myr or tens of Myr, having potentially contributed - by collision-induced heating effect of atmospheric H2 - to the formation of valley networks during the late Noachian and early Hesperian.

  15. Reduced butyrylcholinesterase activity is an early indicator of trauma-induced acute systemic inflammatory response

    Directory of Open Access Journals (Sweden)

    Zivkovic AR

    2016-11-01

    Full Text Available Aleksandar R Zivkovic, Jochen Bender, Thorsten Brenner, Stefan Hofer,* Karsten Schmidt* Department of Anesthesiology, Heidelberg University Hospital, Heidelberg, Germany *These authors contributed equally to this work Purpose: Early diagnosis of systemic inflammatory response syndrome is fundamentally important for an effective and a goal-directed therapy. Various inflammation biomarkers have been used in clinical and experimental practice. However, a definitive diagnostic tool for an early detection of systemic inflammation remains to be identified. Acetylcholine (Ach has been shown to play an important role in the inflammatory response. Serum cholinesterase (butyrylcholinesterase [BChE] is the major Ach hydrolyzing enzyme in blood. The role of this enzyme during inflammation has not yet been fully understood. This study tests whether a reduction in the BChE activity could indicate the onset of the systemic inflammatory response upon traumatic injury. Patients and methods: This observational study measured BChE activity in patients with traumatic injury admitted to the emergency room by using point-of-care-test system (POCT. In addition, the levels of routine inflammation biomarkers during the initial treatment period were measured. Injury Severity Score was used to assess the trauma severity. Results: Altered BChE activity was correlated with trauma severity, resulting in systemic inflammation. Reduction in the BChE activity was detected significantly earlier compared to those of routinely measured inflammatory biomarkers. Conclusion: This study suggests that the BChE activity reduction might serve as an early indicator of acute systemic inflammation. Furthermore, BChE activity, measured using a POCT system, might play an important role in the early diagnosis of the trauma-induced systemic inflammation. Keywords: trauma, injury, early diagnostics, cholinergic, pseudocholinesterase, SIRS

  16. Early postnatal treatment with clomipramine induces female sexual behavior and estrous cycle impairment.

    Science.gov (United States)

    Molina-Jiménez, Tania; Limón-Morales, Ofelia; Bonilla-Jaime, Herlinda

    2018-03-01

    Administration of clomipramine (CMI), a tricyclic antidepressant, in early stages of development in rats, is considered an animal model for the study of depression. This pharmacological manipulation has induced behavioral and physiological alterations, i.e., less pleasure-seeking behaviors, despair, hyperactivity, cognitive dysfunction, alterations in neurotransmitter systems and in HPA axis. These abnormalities in adult male rats are similar to the symptoms observed in major depressive disorders. One of the main pleasure-seeking behaviors affected in male rats treated with CMI is sexual behavior. However, to date, no effects of early postnatal CMI treatment have been reported on female reproductive cyclicity and sexual behavior. Therefore, we explored CMI administration in early life (8-21 PN) on the estrous cycle and sexual behavior of adult female rats. Compared to the rats in the early postnatal saline treatment (CTRL group), the CMI rats had fewer estrous cycles, fewer days in the estrous stage, and longer cycles during a 20-day period of vaginal cytology analysis. On the behavioral test, the CMI rats displayed fewer proceptive behaviors (hopping, darting) and had lower lordosis quotients. Also, they usually failed to display lordosis and only rarely manifested marginal or normal lordosis. In contrast, the CTRL rats tended to display normal lordosis. These results suggest that early postnatal CMI treatment caused long-term disruptions of the estrous cycle and female sexual behavior, perhaps by alteration in the hypothalamic-pituitary-gonadal (HPG) axes and in neuronal circuits involved in the regulation of the performance and motivational of sexual behavior as the noradrenergic and serotonergic systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Experimental study on early detection of alloxan-induced pulmonary injury by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Awai, Kazuo; Fukuda, Hiroshi; Nakamura, Susumu; Fujikawa, Koichi; Utsumi, Toshio; Kajima, Toshio; Azuma, Kazuyoshi; Ito, Katsuhide.

    1995-01-01

    We studied the early detection of alloxan-induced pulmonary injury by magnetic resonance imaging in vivo. Permeability edema was induced in ten rats by intravenous injection of alloxan at 100 mg/Kg. T1-and T2-weighted images were acquired in five rats every 30 min for 120 min after alloxan injection. Five rats served as controls. The rats were sacrificed immediately after imaging and examined microscopically. CT images were also acquired in five rats every 30 min for 120 min after alloxan injection. Five rats served as controls. The rats were sacrificed immediately after imaging, and the wet-to-dry ratio of the lung was measured. In T1-weighted images, relative signal intensity from the lung with permeability edema rose from 30 min to 120 min, and was greater than that from normal lung every time. In T2-weighted images, there was no statistically significant difference in relative signal intensity of the lung between permeability edema and the control during 120 min. In CT images, there was also no statistically significant difference in lung density between permeability edema and the control during 120 min. There was no statistically significant difference in the wet-to-dry lung ratio between edematous lung and normal lung. In histological study, mild congestion and interstitial edema were observed in edematous lung. These results suggest the potential capability of MR imaging in detecting the early phase of permeability pulmonary edema. (author)

  18. Expression of immediate-early genes in the dorsal cochlear nucleus in salicylate-induced tinnitus.

    Science.gov (United States)

    Hu, Shou-Sen; Mei, Ling; Chen, Jian-Yong; Huang, Zhi-Wu; Wu, Hao

    2016-02-01

    Spontaneous neuronal activity in dorsal cochlear nucleus (DCN) may be involved in the physiological processes underlying salicylate-induced tinnitus. As a neuronal activity marker, immediate-early gene (IEG) expression, especially activity-dependent cytoskeletal protein (Arc/Arg3.1) and the early growth response gene-1 (Egr-1), appears to be highly correlated with sensory-evoked neuronal activity. However, their relationships with tinnitus induced by salicylate have rarely been reported in the DCN. In this study, we assessed the effect of acute and chronic salicylate treatment on the expression of N-methyl D-aspartate receptor subunit 2B (NR2B), Arg3.1, and Egr-1. We also observed ultrastructural alterations in the DCN synapses in an animal model of tinnitus. Levels of mRNA and protein expression of NR2B and Arg3.1 were increased in rats that were chronically administered salicylate (200 mg/kg, twice daily for 3, 7, or 14 days). These levels returned to baseline 14 days after cessation of treatment. However, no significant changes were observed in Egr-1 gene expression in any groups. Furthermore, rats subjected to long-term salicylate administration showed more presynaptic vesicles, thicker and longer postsynaptic densities, and increased synaptic interface curvature. Alterations of Arg3.1 and NR2B may be responsible for the changes in the synaptic ultrastructure. These changes confirm that salicylate can cause neural plasticity changes at the DCN level.

  19. Fisetin induces Sirt1 expression while inhibiting early adipogenesis in 3T3-L1 cells.

    Science.gov (United States)

    Kim, Sang Chon; Kim, Yoo Hoon; Son, Sung Wook; Moon, Eun-Yi; Pyo, Suhkneung; Um, Sung Hee

    2015-11-27

    Fisetin (3,7,3',4'-tetrahydroxyflavone) is a naturally found flavonol in many fruits and vegetables and is known to have anti-aging, anti-cancer and anti-viral effects. However, the effects of fisetin on early adipocyte differentiation and the epigenetic regulator controlling adipogenic transcription factors remain unclear. Here, we show that fisetin inhibits lipid accumulation and suppresses the expression of PPARγ in 3T3-L1 cells. Fisetin suppressed early stages of preadipocyte differentiation, and induced expression of Sirt1. Depletion of Sirt1 abolished the inhibitory effects of fisetin on intracellular lipid accumulation and on PPARγ expression. Mechanistically, fisetin facilitated Sirt1-mediated deacetylation of PPARγ and FoxO1, and enhanced the association of Sirt1 with the PPARγ promoter, leading to suppression of PPARγ transcriptional activity, thereby repressing adipogenesis. Lowering Sirt1 levels reversed the effects of fisetin on deacetylation of PPARγ and increased PPARγ transactivation. Collectively, our results suggest the effects of fisetin in increasing Sirt1 expression and in epigenetic control of early adipogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. High-frequency audiometry: A means for early diagnosis of noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Amir H Mehrparvar

    2011-01-01

    Full Text Available Noise-induced hearing loss (NIHL, an irreversible disorder, is a common problem in industrial settings. Early diagnosis of NIHL can help prevent the progression of hearing loss, especially in speech frequencies. For early diagnosis of NIHL, audiometry is performed routinely in conventional frequencies. We designed this study to compare the effect of noise on high-frequency audiometry (HFA and conventional audiometry. In a historical cohort study, we compared hearing threshold and prevalence of hearing loss in conventional and high frequencies of audiometry among textile workers divided into two groups: With and without exposure to noise more than 85 dB. The highest hearing threshold was observed at 4000 Hz, 6000 Hz and 16000 Hz in conventional right ear audiometry, conventional left ear audiometry and HFA in each ear, respectively. The hearing threshold was significantly higher at 16000 Hz compared to 4000. Hearing loss was more common in HFA than conventional audiometry. HFA is more sensitive to detect NIHL than conventional audiometry. It can be useful for early diagnosis of hearing sensitivity to noise, and thus preventing hearing loss in lower frequencies especially speech frequencies.

  1. Expression of the Inducible Nitric Oxide Synthase Isoform in Chorionic Villi in the Early Spontaneous Abortion

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To investigate the relationship between inducible nitric oxide synthase (iNOS) and the early spontaneous abortion. , in situ hybridization and immunohistochemistry were used to detect the expression of iNOS in trophoblasts in the early pregnancy with and without spontaneous abortion (group Ⅰ and group Ⅱ ). By light microscopy and computer color magic image analysis system (CMIAS), light density (D) and the positive cell number per statistic square (N/S) in situ hybridization were used to analyze the positive cell index, while total positive cells (N) and the positive unit (Pu) were used in immunohistochemistry. By in situ hybridization, D and N/S in trophoblasts were 0. 35±0. 028, 0. 07±0. 011 respectively in group Ⅰ and 0. 18±0. 016,0. 015±0. 003 in group Ⅱ . In terms of immunohistochemical staining, N and Pu were 0. 058±±0. 007, 11. 94±2. 01 in group Ⅰ and 0. 013±0. 009, 1. 08±0. 35 in group Ⅱ in trophoblasts. Significant differences existed between two groups. It is concluded that the higher nitric oxide produced by the higher expression of iNOS in trophoblasts might play an important role in the early spontaneous abortion.

  2. Changes in mitochondrial dynamics during ceramide-induced cardiomyocyte early apoptosis.

    Science.gov (United States)

    Parra, Valentina; Eisner, Veronica; Chiong, Mario; Criollo, Alfredo; Moraga, Francisco; Garcia, Alejandra; Härtel, Steffen; Jaimovich, Enrique; Zorzano, Antonio; Hidalgo, Cecilia; Lavandero, Sergio

    2008-01-15

    In cells, mitochondria are organized as a network of interconnected organelles that fluctuate between fission and fusion events (mitochondrial dynamics). This process is associated with cell death. We investigated whether activation of apoptosis with ceramides affects mitochondrial dynamics and promotes mitochondrial fission in cardiomyocytes. Neonatal rat cardiomyocytes were incubated with C(2)-ceramide or the inactive analog dihydro-C(2)-ceramide for up to 6 h. Three-dimensional images of cells loaded with mitotracker green were obtained by confocal microscopy. Dynamin-related protein-1 (Drp-1) and mitochondrial fission protein 1 (Fis1) distribution and levels were studied by immunofluorescence and western blot. Mitochondrial membrane potential (DeltaPsi(m)) and cytochrome c (cyt c) distribution were used as indexes of early activation of apoptosis. Cell viability and DNA fragmentation were determined by propidium iodide staining/flow cytometry, whereas cytotoxicity was evaluated by lactic dehydrogenase activity. To decrease the levels of the mitochondrial fusion protein mitofusin 2, we used an antisense adenovirus (AsMfn2). C(2)-ceramide, but not dihydro-C(2)-ceramide, promoted rapid fragmentation of the mitochondrial network in a concentration- and time-dependent manner. C(2)-ceramide also increased mitochondrial Drp-1 and Fis1 content, Drp-1 colocalization with Fis1, and caused early activation of apoptosis. AsMfn2 accentuated the decrease in DeltaPsi(m) and cyt c redistribution induced by C(2)-ceramide. Doxorubicin, which induces cardiomyopathy and apoptosis through ceramide generation, also stimulated mitochondrial fragmentation. Ceramides stimulate mitochondrial fission and this event is associated with early activation of cardiomyocyte apoptosis.

  3. Intraoperative Inducibility of Atrial Fibrillation Does Not Predict Early Postoperative Atrial Fibrillation.

    Science.gov (United States)

    Lanters, Eva A H; Teuwen, Christophe P; Yaksh, Ameeta; Kik, Charles; van der Does, Lisette J M E; Mouws, Elisabeth M J P; Knops, Paul; van Groningen, Nicole J; Hokken, Thijmen; Bogers, Ad J J C; de Groot, Natasja M S

    2018-03-10

    Early postoperative atrial fibrillation (EPoAF) is associated with thromboembolic events, prolonged hospitalization, and development of late PoAF (LPoAF). It is, however, unknown if EPoAF can be predicted by intraoperative AF inducibility. The aims of this study are therefore to explore (1) the value of intraoperative inducibility of AF for development of both EPoAF and LPoAF and (2) the predictive value of de novo EPoAF for recurrence of LPoAF. Patients (N=496, 75% male) undergoing cardiothoracic surgery for coronary and/or valvular heart disease were included. AF induction was attempted by atrial pacing, before extracorporeal circulation. All patients were on continuous rhythm monitoring until discharge to detect EPoAF. During a follow-up period of 2 years, LPoAF was detected by ECGs and Holter recordings. Sustained AF was inducible in 56% of patients. There was no difference in patients with or without AF before surgery ( P =0.159), or between different types of surgery ( P =0.687). In patients without a history of AF, incidence of EPoAF and LPoAF was 37% and 2%, respectively. EPoAF recurred in 58% patients with preoperative AF, 53% developed LPoAF. There were no correlations between intraoperative inducibility and EPoAF or LPoAF ( P >0.05). EPoAF was not correlated with LPoAF in patients without a history of AF ( P =0.116), in contrast to patients with AF before surgery ( P <0.001). Intraoperative AF inducibility does not predict development of either EPoAF or LPoAF. In patients with AF before surgery, EPoAF is correlated with LPoAF recurrences. This correlation is absent in patients without AF before surgery. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  4. Restoring Serotonergic Homeostasis in the Lateral Hypothalamus Rescues Sleep Disturbances Induced by Early-Life Obesity.

    Science.gov (United States)

    Gazea, Mary; Patchev, Alexandre V; Anderzhanova, Elmira; Leidmaa, Este; Pissioti, Anna; Flachskamm, Cornelia; Almeida, Osborne F X; Kimura, Mayumi

    2018-01-10

    Early-life obesity predisposes to obesity in adulthood, a condition with broad medical implications including sleep disorders, which can exacerbate metabolic disturbances and disrupt cognitive and affective behaviors. In this study, we examined the long-term impact of transient peripubertal diet-induced obesity (ppDIO, induced between 4 and 10 weeks of age) on sleep-wake behavior in male mice. EEG and EMG recordings revealed that ppDIO increases sleep during the active phase but reduces resting-phase sleep quality. This impaired sleep phenotype persisted for up to 1 year, although animals were returned to a non-obesiogenic diet from postnatal week 11 onwards. To better understand the mechanisms responsible for the ppDIO-induced alterations in sleep, we focused on the lateral hypothalamus (LH). Mice exposed to ppDIO did not show altered mRNA expression levels of orexin and melanin-concentrating hormone, two peptides that are important for sleep-wake behavior and food intake. Conversely, the LH of ppDIO-exposed mice had reduced contents of serotonin (5-hydroxytryptamine, 5-HT), a neurotransmitter involved in both sleep-wake and satiety regulation. Interestingly, an acute peripheral injection of the satiety-signaling peptide YY 3-36 increased 5-HT turnover in the LH and ameliorated the ppDIO-induced sleep disturbances, suggesting the therapeutic potential of this peptide. These findings provide new insights into how sleep-wake behavior is programmed during early life and how peripheral and central signals are integrated to coordinate sleep. SIGNIFICANCE STATEMENT Adult physiology and behavior are strongly influenced by dynamic reorganization of the brain during puberty. The present work shows that obesity during puberty leads to persistently dysregulated patterns of sleep and wakefulness by blunting serotonergic signaling in the lateral hypothalamus. It also shows that pharmacological mimicry of satiety with peptide YY 3-36 can reverse this neurochemical imbalance and

  5. Ethylene signalling is mediating the early cadmium-induced oxidative challenge in Arabidopsis thaliana.

    Science.gov (United States)

    Schellingen, Kerim; Van Der Straeten, Dominique; Remans, Tony; Vangronsveld, Jaco; Keunen, Els; Cuypers, Ann

    2015-10-01

    Cadmium (Cd) induces the generation of reactive oxygen species (ROS) and stimulates ethylene biosynthesis. The phytohormone ethylene is a regulator of many developmental and physiological plant processes as well as stress responses. Previous research indicated various links between ethylene signalling and oxidative stress. Our results support a correlation between the Cd-induced oxidative challenge and ethylene signalling in Arabidopsis thaliana leaves. The effects of 24 or 72 h exposure to 5 μM Cd on plant growth and several oxidative stress-related parameters were compared between wild-type (WT) and ethylene insensitive mutants (etr1-1, ein2-1, ein3-1). Cadmium-induced responses observed in WT plants were mainly affected in etr1-1 and ein2-1 mutants, of which the growth was less inhibited by Cd exposure as compared to WT and ein3-1 mutants. Both etr1-1 and ein2-1 showed a delayed response in the glutathione (GSH) metabolism, including GSH levels and transcript levels of GSH synthesising and recycling enzymes. Furthermore, the expression of different oxidative stress marker genes was significantly lower in Cd-exposed ein2-1 mutants, evidencing that ethylene signalling is involved in early responses to Cd stress. A model for the cross-talk between ethylene signalling and oxidative stress is proposed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Early Treatment of radiation-Induced Heart Damage in Rats by Caffeic acid phenethyl Ester

    International Nuclear Information System (INIS)

    Tawfik, S.S.; Mansour, H. H.

    2012-12-01

    The study designed to determine the therapeutic effect of caffeic acid phenethyl ester (CAPE) in minimising radiation-induced injuries in rats. Rats were exposed to 7 Gy γ-rays, 30 minutes later; rats were injected with CAPE (10μmol/ kg body, i.p.) for 7 consecutive days. Rats were sacrificed at 8 and 15 days after starting the experiment. Gamma-irradiation induced significant increase in malonaldehyde (MDA) level and xanthine oxidase (XO) and adenosine deaminase (ADA) activities, and significant decrease in total nitrate/nitrate (NO (x)) level and glutathione peroxidise (Gpx), superoxide dismutase (SOD)and catalase (CAT) activities in heart tissue and augmented activities of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and aspartate transaminase (AST) in serum. Irradiated rats early treated with CAPE showed significant decrease in MDA, XO and ADA and significant increase in group. Cardiac enzymes were restored. Conclusion, CAPE could exhibits curable effect on gamma irradiation-induced cardiac-oxidative impairment in rats. (Author)

  7. Early suppression of adipocyte lipid turnover induces immunometabolic modulation in cancer cachexia syndrome.

    Science.gov (United States)

    Henriques, Felipe Santos; Sertié, Rogério Antônio Laurato; Franco, Felipe Oliveira; Knobl, Pamela; Neves, Rodrigo Xavier; Andreotti, Sandra; Lima, Fabio Bessa; Guilherme, Adilson; Seelaender, Marilia; Batista, Miguel Luiz

    2017-05-01

    Cancer cachexia is a multifactorial syndrome characterized by body weight loss, atrophy of adipose tissue (AT) and systemic inflammation. However, there is limited information regarding the mechanisms of immunometabolic response in AT from cancer cachexia. Male Wistar rats were inoculated with 2 × 10 7 of Walker 256 tumor cells [tumor bearing (TB) rats]. The mesenteric AT (MeAT) was collected on d 0, 4, 7 (early stage), and 14 (cachexia stage) after tumor cell injection. Surgical biopsies for MeAT were obtained from patients who had gastrointestinal cancer with cachexia. Lipolysis showed an early decrease in glycerol release in TB d 4 (TB4) rats in relation to the control, followed by a 6-fold increase in TB14 rats, whereas de novo lipogenesis was markedly lower in the incorporation of glucose into fatty acids in TB14 rats during the development of cachexia. CD11b and CD68 were positive in TB7 and TB14 rats, respectively. In addition, we found cachexia stage results similar to those of animals in MeAT from patients: an increased presence of CD68 + , iNOS2 + , TNFα + , and HSL + cells. In summary, translational analysis of MeAT from patients and an animal model of cancer cachexia enabled us to identify early disruption in Adl turnover and subsequent inflammatory response during the development of cancer cachexia.-Henriques, F. S., Sertié, R. A. L., Franco, F. O., Knobl, P., Neves, R. X., Andreotti, S., Lima, F. B., Guilherme, A., Seelaender, M., Batista, M. L., Jr. Early suppression of adipocyte lipid turnover induces immunometabolic modulation in cancer cachexia syndrome. © FASEB.

  8. Potential early predictors for outcomes of experimental hemorrhagic shock induced by uncontrolled internal bleeding in rats.

    Directory of Open Access Journals (Sweden)

    Zaid A Abassi

    Full Text Available Uncontrolled hemorrhage, resulting from traumatic injuries, continues to be the leading cause of death in civilian and military environments. Hemorrhagic deaths usually occur within the first 6 hours of admission to hospital; therefore, early prehospital identification of patients who are at risk for developing shock may improve survival. The aims of the current study were: 1. To establish and characterize a unique model of uncontrolled internal hemorrhage induced by massive renal injury (MRI, of different degrees (20-35% unilateral nephrectomy in rats, 2. To identify early biomarkers those best predict the outcome of severe internal hemorrhage. For this purpose, male Sprague Dawley rats were anesthetized and cannulas were inserted into the trachea and carotid artery. After abdominal laparotomy, the lower pole of the kidney was excised. During 120 minutes, hematocrit, pO2, pCO2, base excess, potassium, lactate and glucose were measured from blood samples, and mean arterial pressure (MAP was measured through arterial tracing. After 120 minutes, blood loss was determined. Statistical prediction models of mortality and amount of blood loss were performed. In this model, the lowest blood loss and mortality rate were observed in the group with 20% nephrectomy. Escalation of the extent of nephrectomy to 25% and 30% significantly increased blood loss and mortality rate. Two phases of hemodynamic and biochemical response to MRI were noticed: the primary phase, occurring during the first 15 minutes after injury, and the secondary phase, beginning 30 minutes after the induction of bleeding. A Significant correlation between early blood loss and mean arterial pressure (MAP decrements and survival were noted. Our data also indicate that prediction of outcome was attainable in the very early stages of blood loss, over the first 15 minutes after the injury, and that blood loss and MAP were the strongest predictors of mortality.

  9. Phenomenological implications of the flipped SU(5) x U(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Tamvakis, K. (Physics Dept., Univ. of Ioannina (Greece))

    1991-07-01

    We study in detail gauge symmetry breaking in the SU(5)xU(1)'xU(1){sup 4}xSO(10)xSO(6) superstring model, solving the D and F-flatness conditions and taking into account quartic and quintic superpotential terms. We find that, to this order, the model describes two massive generations of quarks and leptons as well as a massless generation expected to receive naturally suppressed masses from higher order non-renormalizable terms. D and F-flatness restricts the number of massless isodoublets to four. We solve the coupled renormalization group equations for the gauge and Yukawa couplings in the two-loop approximation and obtain the top-quark mass as a function of two parameters of the model which could be chosen to be ratios of singlet v.e.v's associated with the surplus (U(1)){sup 4} breaking. We obtain a heavy top-quark with 150GeV {<=} m{sub 1} < 200GeV, for most part of the parameter space, while lower values are possible only in a very small extermal region. We also compute the allowed range of unification parameters (M{sub x}, sin{sup 2} {theta}{sub w}, {alpha}{sub 3}(M{sub w})) in the presence of a heavy top quark. (orig.).

  10. Top-quark mass coupling and classification of weakly coupled heterotic superstring vacua

    International Nuclear Information System (INIS)

    Rizos, J.

    2014-01-01

    The quest for the Standard Model among the huge number of string vacua is usually based on a set of phenomenological criteria related to the massless spectrum of string models. In this work we study criteria associated with interactions in the effective low energy theory and in particular with the presence of the coupling that provides mass to the top quark. Working in the context of the free-fermionic formulation of the heterotic superstring, we demonstrate that, in a big class of phenomenologically promising Z 2 x Z 2 compactifications, these criteria can be expressed entirely in terms of the generalised GSO projection coefficients entering the definition of the models. They are shown to be very efficient in identifying phenomenologically viable vacua, especially in the framework of computer-based search, as they are met by approximately one every 10 4 models. We apply our results in the investigation of a class of supersymmetric Pati-Salam vacua, comprising 10 16 configurations, and we show that when combined with other phenomenological requirements they lead to a relatively small set of about 10 7 Standard Model compatible models that can be fully classified. (orig.)

  11. Top-quark mass coupling and classification of weakly coupled heterotic superstring vacua

    Science.gov (United States)

    Rizos, J.

    2014-06-01

    The quest for the Standard Model among the huge number of string vacua is usually based on a set of phenomenological criteria related to the massless spectrum of string models. In this work we study criteria associated with interactions in the effective low energy theory and in particular with the presence of the coupling that provides mass to the top quark. Working in the context of the free-fermionic formulation of the heterotic superstring, we demonstrate that, in a big class of phenomenologically promising compactifications, these criteria can be expressed entirely in terms of the generalised GSO projection coefficients entering the definition of the models. They are shown to be very efficient in identifying phenomenologically viable vacua, especially in the framework of computer-based search, as they are met by approximately one every models. We apply our results in the investigation of a class of supersymmetric Pati-Salam vacua, comprising configurations, and we show that when combined with other phenomenological requirements they lead to a relatively small set of about Standard Model compatible models that can be fully classified.

  12. On the application of the field-redefinition theorem to the heterotic superstring theory

    Science.gov (United States)

    Pollock, M. D.

    2015-05-01

    The ten-dimensional effective action which defines the heterotic superstring theory at low energy is constructed by hypothesis in such a way that the resulting classical equation of motion for the space-time metric simultaneously implies the vanishing of the beta-function for the N = 1 supersymmetric non-linear sigma-model on the world sheet. At four-loop order it was found by Grisaru and Zanon (see also Freeman et al.) that the effective Lagrangian so constructed differs in the numerical coefficient of the term from that obtained directly from the four-point gravitational scattering amplitude. The two expressions can be related via a metric field redefinition , activation of which, however, results in the appearance of ghosts at higher gravitational order , n > 4, as shown by Lawrence. Here, we prove, after reduction of to the physical dimensionality D = 4, that the corresponding field redefinition yields the identity g' ij = g ij , signified by L 3/ R = 0, in a Friedmann space-time generated by a perfect-fluid source characterized by adiabatic index γ ≡ 1 + p/ ρ, where p is the pressure and ρ is the energy density, if, and only if, κ 6 ρ 3 γ 2( γ - 1) = 0. That is, the theory remains free of ghosts in Minkowski space ρ = 0, in a maximally symmetric space-time γ = 0, or in a dust Universe γ = 1. Further aspects of ghost freedom and dimensional reduction, especially to D = 4, are discussed.

  13. Perturbative quantization of superstring theory in Anti de-Sitter spaces

    Energy Technology Data Exchange (ETDEWEB)

    Sundin, Per

    2010-07-12

    In this thesis we study superstring theory on AdS{sub 5} x S{sup 5}, AdS{sub 3} x S{sup 3} and AdS{sub 4} x CP{sub 3}. A shared feature of each theory is that their corresponding symmetry algebras allows for a decomposition under a Z{sub 4} grading. The grading can be realized through an automorphism which allows for a convenient construction of the string Lagrangians directly in terms of graded components. We adopt a uniform light-cone gauge and expand in a near plane wave limit, or equivalently, an expansion in transverse string coordinates. With a main focus on the two critical string theories, we perform a perturbative quantization up to quartic order in the number of fields. Each string theory is, through holographic descriptions, conjectured to be dual to lower dimensional gauge theories. The conjectures imply that the conformal dimensions of single trace operators in gauge theory should be equal to the energy of string states. What is more, through the use of integrable methods, one can write down a set of Bethe equations whose solutions encode the full spectral problem. One main theme of this thesis is to match the predictions of these equations, written in a language suitable for the light-cone gauge we employ, against explicit string theory calculations. We do this for a large class of string states and the perfect agreement we find lends strong support for the validity of the conjectures. (orig.)

  14. Dyons, Superstrings, and Wormholes: Exact Solutions of the Non-Abelian Dirac-Born-Infeld Action

    Directory of Open Access Journals (Sweden)

    Edward A. Olszewski

    2015-01-01

    Full Text Available We construct dyon solutions on coincident D4-branes, obtained by applying T-duality transformations to type I SO(32 superstring theory in 10 dimensions. These solutions, which are exact, are obtained from an action comprising the non-Abelian Dirac-Born-Infeld action and a Wess-Zumino-like action. When one spatial dimension of the D4-branes is taken to be vanishingly small, the dyons are analogous to the ’t Hooft/Polyakov monopole residing in a 3+1-dimensional spacetime, where the component of the Yang-Mills potential transforming as a Lorentz scalar is reinterpreted as a Higgs boson transforming in the adjoint representation of the gauge group. Applying a T-duality transformation to the vanishingly small spatial dimension, we obtain a collection of D3-branes, not all of which are coincident. Two of the D3-branes, distinct from the others, acquire intrinsic, finite curvature and are connected by a wormhole. The dyons possess electric and magnetic charges whose values on each D3-brane are the negative of one another. The gravitational effects, which arise after the T-duality transformation, occur despite the fact that the action of the system does not explicitly include the gravitational interaction. These solutions provide a simple example of the subtle relationship between the Yang-Mills and gravitational interactions, that is, gauge/gravity duality.

  15. Superstring Z' bozon in e-e+ → ff-bar annihilation

    International Nuclear Information System (INIS)

    Abdullaev, S.K.; Mukhtarov, A.I.

    1989-01-01

    An influence of an additional neutral Z' bozon on characteristics of e - e + →ff-bar processes is studied, where ff-bar is a pair of arbitrary particles (leptons, nucleons, hyperons, pseudoscalar or vector mesons etc.). The general expression for the differential cross sections of e - e + →ff-bar processes is obtained with arbitrary polarizations of an electron-positron pair by introducing of structure functions, and the following integral characteristics are considered: polarized forward A F (λ 2 ) and backward A B (λ 2 ) assymmetries; right-left asymmetry A RL ; forward-backward asymmetry in the case of longitudinal polarized e - e + pair annihilation A BH (λ 2 ); transversal spin assymmetries A Φ (1) and A Φ (2) ; the degree of longitudinal polarization of r lepton P in e - e + → r - r + r - r + process. The general expressions for these characteristics are found and their quantitative estimates are given in the framework of superstring E 6 -model. 20 refs.; 5 figs.; 2 tabs

  16. q-Virasoro algebra, q-conformal dimensions and free q-superstring

    International Nuclear Information System (INIS)

    Chaichian, M.

    1996-01-01

    The commutators of standard Virasoro generators and fields generate various representations of the centreless Virasoro algebra depending on a conformal dimension J of the field in question (J is related to the Bargmann index of SU(1,1) generated by L m , m=0,±1). We introduce the notion of q-conformal dimension for various oscillator realizations of q-deformed Virasoro (super)algebras proposed earlier. We use the field theoretical approach introduced recently in which the q-Virasoro currents L α (z) are expressed as Schwinger-like point-split normally ordered quadratic expressions in elementary fields. We extend this approach and probe the elementary fields A(z) (the q-superstring coordinate, momentum and fermionic field) and their powers by the q-Virasoro generators L α m (i.e. we calculate the commutators [L α m ,A(z)]) and show that to all of them can be assigned just the standard non-deformed conformal dimension. (orig.)

  17. Superstrings, entropy and the elementary particles content of the standard model

    International Nuclear Information System (INIS)

    El Naschie, M.S.

    2006-01-01

    A number of interconnected issues involving superstring theory, entropy and the particle content of the standard model of high energy physics are discussed in the present work. It is found that within a non-transfinite approximation, the number of elementary particles is given by DimSU(8) in full agreement with the prediction gained from dividing the total number of the massless level of Heterotic string theory (256)(16)=8064 by the spin representation 2 7 =128 which gives DimSU(8)=(8) 2 -1=(8064)/(128)=63 particles. For the exact transfinite case however, one finds our previously established E-infinity result:N=(336+16k)(3/2+k)(16+k)/(128+8k)=α-bar o /2,where k=φ 3 (1-φ 3 ), φ=(5-1)/2 and α-bar o /2=68.54101965. Setting k=0 one finds that n=63 exactly as in the non-transfinite case

  18. Perturbative quantization of superstring theory in Anti de-Sitter spaces

    International Nuclear Information System (INIS)

    Sundin, Per

    2010-01-01

    In this thesis we study superstring theory on AdS 5 x S 5 , AdS 3 x S 3 and AdS 4 x CP 3 . A shared feature of each theory is that their corresponding symmetry algebras allows for a decomposition under a Z 4 grading. The grading can be realized through an automorphism which allows for a convenient construction of the string Lagrangians directly in terms of graded components. We adopt a uniform light-cone gauge and expand in a near plane wave limit, or equivalently, an expansion in transverse string coordinates. With a main focus on the two critical string theories, we perform a perturbative quantization up to quartic order in the number of fields. Each string theory is, through holographic descriptions, conjectured to be dual to lower dimensional gauge theories. The conjectures imply that the conformal dimensions of single trace operators in gauge theory should be equal to the energy of string states. What is more, through the use of integrable methods, one can write down a set of Bethe equations whose solutions encode the full spectral problem. One main theme of this thesis is to match the predictions of these equations, written in a language suitable for the light-cone gauge we employ, against explicit string theory calculations. We do this for a large class of string states and the perfect agreement we find lends strong support for the validity of the conjectures. (orig.)

  19. Sex differences in stress-induced visceral hypersensitivity following early life adversity: a two hit model.

    Science.gov (United States)

    Prusator, D K; Greenwood-Van Meerveld, B

    2016-12-01

    Early life adversity (ELA) has been indicated as a risk factor for the development of stress axis dysfunction in adulthood, specifically in females. We previously showed that unpredictable ELA induces visceral hyperalgesia in adult female rats. It remains to be determined whether ELA alters visceral nociceptive responses to stress in adulthood. The current study tested the hypothesis that following ELA, exposure to an adulthood stressor, or second hit, serves as a risk factor for exaggerated stress-induced visceral hypersensitivity that is sex-specific. Following ELA, adult stress was induced via a single exposure (acute) or repetitive daily exposure, 1 h/day for 7 days (chronic), to water avoidance stress (WAS). Acute WAS increased pain behaviors in all adult female rats, however, females that experienced unpredictable ELA exhibited significantly more pain behaviors compared to those exposed to predictable ELA or controls. Following chronic WAS, all adult females exhibited increased pain responses, however, an exaggerated response was observed in rats exposed to unpredictable or predictable ELA compared to controls. Similarly, in adult male rats exposure to acute or chronic WAS increased pain behaviors, however, there were no differences in pain behaviors between ELA groups. This study highlights a novel consequence of ELA on stress-induced visceral nociception in adulthood that is sex-specific. More importantly, our study suggests that ELA not only serves as a risk factor for development of chronic pain in adulthood, but also serves as a predisposition for worsening of visceral pain following adult stress in female rats. © 2016 John Wiley & Sons Ltd.

  20. Prevention of organophosphate-induced chronic epilepsy by early benzodiazepine treatment.

    Science.gov (United States)

    Shrot, Shai; Ramaty, Erez; Biala, Yoav; Bar-Klein, Guy; Daninos, Moshe; Kamintsky, Lyn; Makarovsky, Igor; Statlender, Liran; Rosman, Yossi; Krivoy, Amir; Lavon, Ophir; Kassirer, Michael; Friedman, Alon; Yaari, Yoel

    2014-09-02

    Poisoning with organophosphates (OPs) may induce status epilepticus (SE), leading to severe brain damage. Our objectives were to investigate whether OP-induced SE leads to the emergence of spontaneous recurrent seizures (SRSs), the hallmark of chronic epilepsy, and if so, to assess the efficacy of benzodiazepine therapy following SE onset in preventing the epileptogenesis. We also explored early changes in hippocampal pyramidal cells excitability in this model. Adult rats were poisoned with the paraoxon (450μg/kg) and immediately treated with atropine (3mg/kg) and obidoxime (20mg/kg) to reduce acute mortality due to peripheral acetylcholinesterase inhibition. Electrical brain activity was assessed for two weeks during weeks 4-6 after poisoning using telemetric electrocorticographic intracranial recordings. All OP-poisoned animals developed SE, which could be suppressed by midazolam. Most (88%) rats which were not treated with midazolam developed SRSs, indicating that they have become chronically epileptic. Application of midazolam 1min following SE onset had a significant antiepileptogenic effect (only 11% of the rats became epileptic; p=0.001 compared to non-midazolam-treated rats). Applying midazolam 30min after SE onset did not significantly prevent chronic epilepsy. The electrophysiological properties of CA1 pyramidal cells, assessed electrophysiologically in hippocampal slices, were not altered by OP-induced SE. Thus we show for the first time that a single episode of OP-induced SE in rats leads to the acquisition of chronic epilepsy, and that this epileptogenic outcome can be largely prevented by immediate, but not delayed, administration of midazolam. Extrapolating these results to humans would suggest that midazolam should be provided together with atropine and an oxime in the immediate pharmacological treatment of OP poisoning. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

    Science.gov (United States)

    Dong, Jing; Gao, Lingqi; Han, Junde; Zhang, Junjie; Zheng, Jijian

    2017-07-01

    Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

  2. Direct evidence that radiation induced micronuclei of early embryos require a mitosis for expression

    International Nuclear Information System (INIS)

    Mueller, W.U.; Schlusen, I.; Streffer, C.

    1991-01-01

    The naturally synchronous development of early mouse embryos was exploited to address the question, whether micronuclei require a mitosis for expression or whether they can be expressed in the same cell cycle, in which exposure to X-rays or caffeine took place. Experiments with 2-cell and with 4-cell embryos showed that micronulcei are expressed only if a mitosis is completed. There was no indication, even after doses up to 20 Gy, that micronuclei can be expressed before the mitosis was reached, which followed exposure. Furthermore, no nuclear fragmentation pointing to apoptosis could be detected in the cycle, in which cells were exposed. The same results were obtained when caffeine (5 mM) was used as micronucleus inducing agent. (orig.)

  3. Are plant endogenous factors like ethylene modulators of the early oxidative stress induced by mercury?

    Directory of Open Access Journals (Sweden)

    M Belén eMontero-Palmero

    2014-08-01

    Full Text Available The induction of oxidative stress is one of the quickest symptoms appearing in plants subjected to metal stress. A transcriptional analysis of the early responses of alfalfa (Medicago sativa seedlings to mercury (Hg; 3 µM for 3, 6 and 24 h showed that up-regulation of genes responding to ethylene were up-regulated, a phytohormone known to mediate in the cellular redox homeostasis. In this mini-review we have compared these quick responses with two other concurrent transcriptomic analysis in Barrel medic (Medicago truncatula and barley (Hordeum vulgare under Hg stress. Besides ethylene, ABA and jasmonate related genes were up-regulated, all of them are endogenous factors known to intervene in oxidative stress responses. The information obtained may target future work to understand the cellular mechanisms triggered by Hg, enabling biotechnological approaches to diminish Hg-induced phytotoxicity.

  4. Early or late antibiotic intervention prevents Helicobacter pylori-induced gastric cancer in a mouse model.

    Science.gov (United States)

    Zhang, Songhua; Lee, Dong Soo; Morrissey, Rhiannon; Aponte-Pieras, Jose R; Rogers, Arlin B; Moss, Steven F

    2014-12-01

    H. pylori infection causes gastritis, peptic ulcers and gastric cancer. Eradicating H. pylori prevents ulcers, but to what extent this prevents cancer remains unknown, especially if given after intestinal metaplasia has developed. H. pylori infected wild-type (WT) mice do not develop cancer, but mice lacking the tumor suppressor p27 do so, thus providing an experimental model of H. pylori-induced cancer. We infected p27-deficient mice with H. pylori strain SS1 at 6-8 weeks of age. Persistently H. pylori-infected WT C57BL/6 mice served as controls. Mice in the eradication arms received antimicrobial therapy (omeprazole, metronidazole and clarithromycin) either "early" (at 15 weeks post infection, WPI) or "late" at 45 WPI. At 70 WPI, mice were euthanized for H. pylori determination, histopathology and cytokine/chemokine expression. Persistently infected mice developed premalignant lesions including high-grade dysplasia, whereas those given antibiotics did not. Histologic activity scores in the eradication groups were similar to each other, and were significantly decreased compared with controls for inflammation, epithelial defects, hyperplasia, metaplasia, atrophy and dysplasia. IP-10 and MIG levels in groups that received antibiotics were significantly lower than controls. There were no significant differences in expression of IFN-γ, TNF-α, IL-1β, RANTES, MCP-1, MIP-1α or MIP-1β among the three groups. Thus, H. pylori eradication given either early or late after infection significantly attenuated gastric inflammation, gastric atrophy, hyperplasia, and dysplasia in the p27-deficient mice model of H. pylori-induced gastric cancer, irrespective of the timing of antibiotic administration. This was associated with reduced expression of IP-10 and MIG. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Eriodictyol prevents early retinal and plasma abnormalities in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Bucolo, Claudio; Leggio, Gian Marco; Drago, Filippo; Salomone, Salvatore

    2012-07-01

    Diabetic retinopathy is a complex disease that has potential involvement of inflammatory and oxidative stress-related pathways in its pathogenesis. We hypothesized that eriodictyol, one of the most abundant dietary flavonoids, could be effective against diabetic retinopathy, which involves significant oxidative stress and inflammation. The aim of the present study was to investigate the effects of eriodictyol in early retinal and plasma changes of streptozotocin-induced diabetic rats. The effect of eriodictyol treatment (0.1, 1, 10 mg/kg daily for 10 days) was evaluated by TNF-α, ICAM-1, VEGF, and eNOS protein levels measurement in the retina, plasma lipid peroxidation, and blood-retinal barrier (BRB) integrity. Increased amounts of cytokines, adhesion molecule, and nitric oxide synthase were observed in retina from diabetic rats. Eriodictyol treatment significantly lowered retinal TNF-α, ICAM-1, VEGF, and eNOS in a dose-dependent manner. Further, treatment with eriodictyol significantly suppressed diabetes-related lipid peroxidation, as well as the BRB breakdown. These data demonstrated that eriodictyol attenuates the degree of retinal inflammation and plasma lipid peroxidation preserving the BRB in early diabetic rats. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Egg clutch dehydration induces early hatching in red-eyed treefrogs, Agalychnis callidryas

    Directory of Open Access Journals (Sweden)

    María José Salica

    2017-07-01

    Full Text Available Terrestrial eggs have evolved repeatedly in tropical anurans exposing embryos to the new threat of dehydration. Red-eyed treefrogs, Agalychnis callidryas, lay eggs on plants over water. Maternally provided water allows shaded eggs in humid sites to develop to hatching without rainfall, but unshaded eggs and those in less humid sites can die from dehydration. Hatching responses of amphibian eggs to dry conditions are known from two lineages with independent origins of terrestrial eggs. Here, we experimentally tested for dehydration-induced early hatching in another lineage (Agalychnis callidryas, Phyllomedusidae, representing a third independent origin of terrestrial eggs. We also investigated how dehydration affected egg and clutch structure, and egg mortality. We collected clutches from a pond in Gamboa, Panama, and randomly allocated them to wet or dry treatments at age 1 day. Embryos hatched earlier from dry clutches than from wet clutches, accelerating hatching by ∼11%. Clutch thickness and egg diameter were affected by dehydration, diverging between treatments over time. Meanwhile, mortality in dry clutches was six-fold higher than in control clutches. With this study, early hatching responses to escape mortality from egg dehydration are now known from three anuran lineages with independent origins of terrestrial eggs, suggesting they may be widespread. Further studies are needed to understand how terrestrial amphibian eggs can respond to, or will be affected by, rapid changes in climate over the next decades.

  7. Salicylate-induced changes in immediate-early genes in the hippocampal CA1 area.

    Science.gov (United States)

    Wu, Hao; Xu, Feng-Lei; Yin, Yong; Da, Peng; You, Xiao-Dong; Xu, Hui-Min; Tang, Yan

    2015-08-01

    Studies have suggested that salicylate affects neuronal function via interactions with specific membrane channels/receptors. However, the effect of salicylate on activity and synaptic morphology of the hippocampal Cornu Ammonis (CA) 1 area remains to be elucidated. The activation of immediate-early genes (IEGs) was reported to correlate with neuronal activity, in particular activity-regulated cytoskeleton-associated protein and early growth response gene 1. The aim of the present study was to evaluate the expression of these IEGs, as well that of N-methyl D-aspartate (NMDA) receptor subunit 2B in rats following acute and chronic salicylate treatment. Protein and messenger RNA levels of all three genes were increased in rats following chronic administration of salicylate (300 mg/kg for 10 days), returning to baseline levels 14 days post-cessation of treatment. The transient upregulation of gene expression following treatment was accompanied by ultrastructural alterations in hippocampal CA1 area synapses. An increase in synaptic interface curvature was observed as well as an increased number of presynaptic vesicles; in addition, postsynaptic densities thickened and lengthened. In conclusion, the results of the present study indicated that chronic exposure to salicylate may lead to structural alteration of hippocampal CA1 neurons, and it was suggested that this process occurs through induced expression of IEGs via NMDA receptor activation.

  8. Early detection of doxorubicin-induced cariotoxocity and its prevention by alpha-tocopherol

    International Nuclear Information System (INIS)

    Ajmal, K.; Khan, B.T.

    2014-01-01

    To detect doxorubicin-induced myocardial injury by quantitative estimation of cardiospecific protein, Cardiac Troponin I (cTnI) at early stage and to evaluate the cardioprotective effects of Tocopherol. Study Design: Labbased randomized controlled in-vivo study in rabbits. Place and Duration of Study: Department of Pharmacology in collaboration with Pathology department, Army Medical College Rawalpindi, Pakistan from Jan 2012 to Dec 2012. Material and Methods: Eighteen healthy male adult rabbits were used. Cardiotoxicity was induced by single intravenous injection of 12 mg /kg of doxorubicin in a group of rabbits, control group was treated with normal saline only and the rabbits of third group were pretreated with Tocopherol 200 mg/kg of body weight for ten days before injection of doxorubicin 12mg/kg. Results: Doxorubicin produced severe cardiotoxicity confirmed by markedly raised serum levels of cTnI, CK-MB, LDH and grade 3 necrosis of the heart issue in rabbits. The pre-treatment with Tocopherol resulted in improved serum levels of cTnI and the histological picture of heart tissue. Conclusions: The quantitative cTnI estimation for detection of cardiotoxicity at subclinical level can lead to significant economic impact in management of cancer patients because the troponin-negative subjects can be excluded from long term cardiac monitoring programs, which require high cost imaging techniques. Furthermore, the outcome of most potent and widely used doxorubicin chemotherapy can be made successful with the concurrent use of alpha-Tocopherol. (author)

  9. Association of malignancy with rapid growth in early lesions induced by irradiation of rat skin

    International Nuclear Information System (INIS)

    McGregor, J.F.

    1979-01-01

    Epithelial lesions induced by irradiation of rat skin were studied to determine (a) the relationship of malignancy to dose, (b) the types of lesions and circumstances leading to overt malignancy, and (c) the growth rates of lesions progressing to malignancy versus those of lesions remaining benign. High doses of radiation were shown to be associated with the production of epidermal cancers, the maximum yield being obtained at 6,400 rads. Conversely, a peak yield of noncancerous lesions was obtained at 1,600 rads. This association between malignancy and high dose was consistent for cancers evolving from warts, cysts, and chronic ulcers. Although the proportion of warts among the induced lesions was much higher than that of the cysts or chronic ulcers (76, 14, and 10%, respectively), the likelihood of warts becoming cancerous was substantially lower (14, 23, and 21%). The combined data for all doses showed that the latency period of the epidermal cancers was significantly (P = 0.015) shorter than that of the benign tumors. Rapid growth rates were observed for warts, cysts, and chronic ulcers progressing to overt cancer, and these did not overlap at any point on the growth scale with rates for benign tumors. This finding suggested that the potential for malignant development had been established early in the carcinogenic process, very likely at induction

  10. Neutrino-Induced Nucleosynthesis in Helium Shells of Early Core-Collapse Supernovae

    Directory of Open Access Journals (Sweden)

    Banerjee Projjwal

    2016-01-01

    Full Text Available We summarize our studies on neutrino-driven nucleosynthesis in He shells of early core-collapse supernovae with metallicities of Z ≲ 10−3 Z⊙. We find that for progenitors of ∼ 11–15 M⊙, the neutrons released by 4He(ν¯ee, e+n3H in He shells can be captured to produce nuclei with mass numbers up to A ∼ 200. This mechanism is sensitive to neutrino emission spectra and flavor oscillations. In addition, we find two new primary mechanisms for neutrino-induced production of 9Be in He shells. The first mechanism produces 9Be via 7Li(n,γ8Li(n,γ9Li(e− ν¯ee9Be and relies on a low explosion energy for its survival. The second mechanism operates in progenitors of ∼ 8 M⊙, where 9Be can be produced directly via 7Li(3H, n09Be during the rapid expansion of the shocked Heshell material. The light nuclei 7Li and 3H involved in these mechanisms are produced by neutrino interactions with 4He. We discuss the implications of neutrino-induced nucleosynthesis in He shells for interpreting the elemental abundances in metal-poor stars.

  11. Toxicoproteomics: serum proteomic pattern diagnostics for early detection of drug induced cardiac toxicities and cardioprotection.

    Science.gov (United States)

    Petricoin, Emanuel F; Rajapaske, Vinodh; Herman, Eugene H; Arekani, Ali M; Ross, Sally; Johann, Donald; Knapton, Alan; Zhang, J; Hitt, Ben A; Conrads, Thomas P; Veenstra, Timothy D; Liotta, Lance A; Sistare, Frank D

    2004-01-01

    Proteomics is more than just generating lists of proteins that increase or decrease in expression as a cause or consequence of pathology. The goal should be to characterize the information flow through the intercellular protein circuitry which communicates with the extracellular microenvironment and then ultimately to the serum/plasma macroenvironment. The nature of this information can be a cause, or a consequence, of disease and toxicity based processes as cascades of reinforcing information percolate through the system and become reflected in changing proteomic information content of the circulation. Serum Proteomic Pattern Diagnostics is a new type of proteomic platform in which patterns of proteomic signatures from high dimensional mass spectrometry data are used as a diagnostic classifier. While this approach has shown tremendous promise in early detection of cancers, detection of drug-induced toxicity may also be possible with this same technology. Analysis of serum from rat models of anthracycline and anthracenedione induced cardiotoxicity indicate the potential clinical utility of diagnostic proteomic patterns where low molecular weight peptides and protein fragments may have higher accuracy than traditional biomarkers of cardiotoxicity such as troponins. These fragments may one day be harvested by circulating nanoparticles designed to absorb, enrich and amplify the diagnostic biomarker repertoire generated even at the critical initial stages of toxicity.

  12. Early treatment of chlorine-induced airway hyperresponsiveness and inflammation with corticosteroids

    Energy Technology Data Exchange (ETDEWEB)

    Jonasson, Sofia, E-mail: sofia.jonasson@foi.se [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Wigenstam, Elisabeth [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Department of Public Health and Clinical Medicine, Unit of Respiratory Medicine, Umeå University, Umeå (Sweden); Koch, Bo [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Bucht, Anders [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Department of Public Health and Clinical Medicine, Unit of Respiratory Medicine, Umeå University, Umeå (Sweden)

    2013-09-01

    Chlorine (Cl{sub 2}) is an industrial gas that is highly toxic and irritating when inhaled causing tissue damage and an acute inflammatory response in the airways followed by a long-term airway dysfunction. The aim of this study was to evaluate whether early anti-inflammatory treatment can protect against the delayed symptoms in Cl{sub 2}-exposed mice. BALB/c mice were exposed by nose-only inhalation using 200 ppm Cl{sub 2} during 15 min. Assessment of airway hyperresponsiveness (AHR), inflammatory cell counts in bronchoalveolar lavage, occurrence of lung edema and lung fibrosis were analyzed 24 h or 14 days post-exposure. A single dose of the corticosteroid dexamethasone (10 or 100 mg/kg) was administered intraperitoneally 1, 3, 6, or 12 h following Cl{sub 2} exposure. High-dose of dexamethasone reduced the acute inflammation if administered within 6 h after exposure but treated animals still displayed a significant lung injury. The effect of dexamethasone administered within 1 h was dose-dependent; high-dose significantly reduced acute airway inflammation (100 mg/kg) but not treatment with the relatively low-dose (10 mg/kg). Both doses reduced AHR 14 days later, while lung fibrosis measured as collagen deposition was not significantly reduced. The results point out that the acute inflammation in the lungs due to Cl{sub 2} exposure only partly is associated with the long-term AHR. We hypothesize that additional pathogenic mechanisms apart from the inflammatory reactions contribute to the development of long-term airway dysfunction. By using this mouse model, we have validated early administration of corticosteroids in terms of efficacy to prevent acute lung injury and delayed symptoms induced by Cl{sub 2} exposure. - Highlights: • Inhalation of Cl{sub 2} may lead to a long-standing airway hyperresponsiveness. • The symptoms in Cl{sub 2}-exposed mice are similar to those described for RADS in humans. • Corticosteroids prevent delayed symptoms such as AHR in

  13. NREL Determines Long-Lived Carriers and Differences in CdTe Superstrate and Substrate Cells (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-01

    NREL study may provide future guidance in improving CdS/CdTe photovoltaic device performance. The majority of minority carrier lifetime (MCL) studies performed on CdS/CdTe photovoltaic (PV) devices have correlated device performance primarily with the fast decay observed in time-resolved photoluminescence (TRPL) measurements (t{sub 1}). This decay is believed to be associated primarily with recombination in depletion width (W{sub D}), and therefore should be a good indicator of device quality if carrier generation occurs primarily within WD. However, although previous studies have shown that t1 can be a good indicator of broad device quality, it does not correlate as well with small changes in device performance and/or with differences observed between superstrate and substrate devices. Researchers at the National Renewable Energy Laboratory (NREL) have shown that in this case, the parameter t{sub 2} (from the longer-term decay of TRPL) may not only provide a better correlation with device open-circuit voltage (V{sub OC}) for superstrate devices but may also provide guidance for inter-comparison with alternative device designs (e.g., substrate devices). It is also suggested that previous studies may yield added value if a larger number of TRPL parameters (i.e., t{sub 1}, t{sub 2}, and respective amplitudes) are re-examined as a function of device performance. The parameter t{sub 2} may not only provide a better correlation with device VOC for superstrate devices but may also provide guidance for inter-comparison with alternative device designs (e.g., substrate devices).

  14. Apoptosis-related genes induced in response to ketamine during early life stages of zebrafish.

    Science.gov (United States)

    Félix, Luís M; Serafim, Cindy; Valentim, Ana M; Antunes, Luís M; Matos, Manuela; Coimbra, Ana M

    2017-09-05

    Increasing evidence supports that ketamine, a widely used anaesthetic, potentiates apoptosis during development through the mitochondrial pathway of apoptosis. Defects in the apoptotic machinery can cause or contribute to the developmental abnormalities previously described in ketamine-exposed zebrafish. The involvement of the apoptotic machinery in ketamine-induced teratogenicity was addressed by assessing the apoptotic signals at 8 and 24 hpf following 20min exposure to ketamine at three stages of early zebrafish embryo development (256 cell, 50% epiboly and 1-4 somites stages). Exposure at the 256-cell stage to ketamine induced an up-regulation of casp8 and pcna at 8 hpf while changes in pcna at the mRNA level were observed at 24 hpf. After the 50% epiboly stage exposure, the mRNA levels of casp9 were increased at 8 and 24 hpf while aifm1 was affected at 24 hpf. Both tp53 and pcna expressions were increased at 8 hpf. After exposure during the 1-4 somites stage, no meaningful changes on transcript levels were observed. The distribution of apoptotic cells and the caspase-like enzymatic activities of caspase-3 and -9 were not affected by ketamine exposure. It is proposed that ketamine exposure at the 256-cell stage induced a cooperative mechanism between proliferation and cellular death while following exposure at the 50% epiboly, a p53-dependent and -independent caspase activation may occur. Finally, at the 1-4 somites stage, the defence mechanisms are already fully in place to protect against ketamine-insult. Thus, ketamine teratogenicity seems to be dependent on the functional mechanisms present in each developmental stage. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Subtoxic Alterations in Hepatocyte-Derived Exosomes: An Early Step in Drug-Induced Liver Injury?

    Science.gov (United States)

    Holman, Natalie S; Mosedale, Merrie; Wolf, Kristina K; LeCluyse, Edward L; Watkins, Paul B

    2016-06-01

    Drug-induced liver injury (DILI) is a significant clinical and economic problem in the United States, yet the mechanisms that underlie DILI remain poorly understood. Recent evidence suggests that signaling molecules released by stressed hepatocytes can trigger immune responses that may be common across DILI mechanisms. Extracellular vesicles released by hepatocytes, principally hepatocyte-derived exosomes (HDEs), may constitute one such signal. To examine HDE alterations as a function of drug-induced stress, this work utilized prototypical hepatotoxicant acetaminophen (APAP) in male Sprague-Dawley (SD) rats, SD rat hepatocytes, and primary human hepatocytes. HDE were isolated using ExoQuick precipitation reagent and analyzed by quantification of the liver-specific RNAs albumin and microRNA-122 (miR-122). In vivo, significant elevations in circulating exosomal albumin mRNA were observed at subtoxic APAP exposures. Significant increases in exosomal albumin mRNA were also observed in primary rat hepatocytes at subtoxic APAP concentrations. In primary human hepatocytes, APAP elicited increases in both exosomal albumin mRNA and exosomal miR-122 without overt cytotoxicity. However, the number of HDE produced in vitro in response to APAP did not increase with exosomal RNA quantity. We conclude that significant drug-induced alterations in the liver-specific RNA content of HDE occur at subtoxic APAP exposures in vivo and in vitro, and that these changes appear to reflect selective packaging rather than changes in exosome number. The current findings demonstrate that translationally relevant HDE alterations occur in the absence of overt hepatocellular toxicity, and support the hypothesis that HDE released by stressed hepatocytes may mediate early immune responses in DILI. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Early biomarkers of doxorubicin-induced heart injury in a mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Varsha G., E-mail: varsha.desai@fda.hhs.gov [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Kwekel, Joshua C.; Vijay, Vikrant; Moland, Carrie L. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Herman, Eugene H. [Toxicology and Pharmacology Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, The National Cancer Institute, 9609 Medical Center Drive, Rockville, MD 20850-9734 (United States); Lee, Taewon [Department of Mathematics, Korea University, Sejong, Chungnam 339-700 (Korea, Republic of); Han, Tao [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lewis, Sherry M. [Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Davis, Kelly J.; Muskhelishvili, Levan [Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR 72079 (United States); Kerr, Susan [Arkansas Heart Hospital, Little Rock, AR 72211 (United States); Fuscoe, James C. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

    2014-12-01

    Cardiac troponins, which are used as myocardial injury markers, are released in plasma only after tissue damage has occurred. Therefore, there is a need for identification of biomarkers of earlier events in cardiac injury to limit the extent of damage. To accomplish this, expression profiling of 1179 unique microRNAs (miRNAs) was performed in a chronic cardiotoxicity mouse model developed in our laboratory. Male B6C3F{sub 1} mice were injected intravenously with 3 mg/kg doxorubicin (DOX; an anti-cancer drug), or saline once a week for 2, 3, 4, 6, and 8 weeks, resulting in cumulative DOX doses of 6, 9, 12, 18, and 24 mg/kg, respectively. Mice were euthanized a week after the last dose. Cardiac injury was evidenced in mice exposed to 18 mg/kg and higher cumulative DOX dose whereas examination of hearts by light microscopy revealed cardiac lesions at 24 mg/kg DOX. Also, 24 miRNAs were differentially expressed in mouse hearts, with the expression of 1, 1, 2, 8, and 21 miRNAs altered at 6, 9, 12, 18, and 24 mg/kg DOX, respectively. A pro-apoptotic miR-34a was the only miRNA that was up-regulated at all cumulative DOX doses and showed a significant dose-related response. Up-regulation of miR-34a at 6 mg/kg DOX may suggest apoptosis as an early molecular change in the hearts of DOX-treated mice. At 12 mg/kg DOX, up-regulation of miR-34a was associated with down-regulation of hypertrophy-related miR-150; changes observed before cardiac injury. These findings may lead to the development of biomarkers of earlier events in DOX-induced cardiotoxicity that occur before the release of cardiac troponins. - Highlights: • Upregulation of miR-34a before doxorubicin-induced cardiac tissue injury • Apoptosis might be an early event in mouse heart during doxorubicin treatment. • Expression of miR-150 declined before doxorubicin-induced cardiac tissue injury.

  17. Gauge symmetry breaking in the hidden sector of the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, I.; Rizos, J. (Centre de Physique Theorique, Ecole Polytechnique, 91 - Palaiseau (France)); Tamvakis, K. (Theoretical Physics Div., Univ. Ioannina (Greece))

    1992-03-26

    We analyze the SU(5)xU(1)'xU(1){sup 4}xSO(10)xSU(4) superstring model with a spontaneously broken hidden sector down to SO(7)xSO(5) taking into account non-renormalizable superpotential terms up to eight order. As a result of the hidden sector breaking the 'exotic' states get a mass and the 'observable' spectrum is composed of the standard three families. In addition, Cabibbo mixing arises at sixth order and an improved fermion mass hierarchy emerges. (orig.).

  18. Superstring Theory on $AdS_{3} x G/H$ and Boundary N=3 Superconformal Symmetry

    CERN Document Server

    Argurio, R; Shomer, A; Argurio, Riccardo; Giveon, Amit; Shomer, Assaf

    2000-01-01

    Superstrings propagating on backgrounds of the form AdS_3 x G/H are studiedusing the coset CFT approach. We focus on seven dimensional cosets which have asemiclassical limit, and which give rise to N=3 superconformal symmetry in thedual CFT. This is realized for the two cases AdS_3 x SU(3)/U(1) and AdS_3 xSO(5)/SO(3), for which we present an explicit construction. We also providesufficient conditions on a CFT background to enable a similar construction, andcomment on the geometrical interpretation of our results.

  19. A{sub ∞}/L{sub ∞} structure and alternative action for WZW-like superstring field theory

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Keiyu [Institute of Physics, University of Tokyo,Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Matsunaga, Hiroaki [Institute of Physics, Academy of Sciences of the Czech Republic,Na Slovance 2, Prague 8 (Czech Republic); Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan)

    2017-01-09

    We propose new gauge invariant actions for open NS, heterotic NS, and closed NS-NS superstring field theories. They are based on the large Hilbert space, and have Wess-Zumino-Witten-like expressions which are the ℤ{sub 2}-reversed versions of the conventional WZW-like actions. On the basis of the procedure proposed in https://arxiv.org/abs/1505.01659, we show that our new WZW-like actions are completely equivalent to A{sub ∞}/L{sub ∞} actions proposed in https://arxiv.org/abs/1403.0940 respectively.

  20. Superstring field theories on super-flag manifolds: superdiff S1/S1 and superdiff S1/super S1

    International Nuclear Information System (INIS)

    Zhao Zhiyong; Wu, Ke; Saito, Takesi

    1987-01-01

    We generalize the geometric approach of Bowick and Rajeev [BR] to superstring field theories. The anomaly is identified with nonvanishing of the Ricci curvature of the super-flag manifold. We explicitly calculate the curvatures of superdiff S 1 /S 1 and superdiff S 1 /superS 1 using super-Toeplitz operator techniques. No regularization is needed in this formalism. The critical dimension D=10 is rediscovered as a result of vanishing curvature of the product bundle over the super-flag manifold. (orig.)

  1. Early-life adversity facilitates acquisition of cocaine self-administration and induces persistent anhedonia

    Directory of Open Access Journals (Sweden)

    Jessica L. Bolton

    2018-02-01

    Full Text Available Early-life adversity increases the risk for emotional disorders such as depression and schizophrenia. Anhedonia, thought to be a core feature of these disorders, is provoked by our naturalistic rodent model of childhood adversity (i.e., rearing pups for one week in cages with limited bedding and nesting, LBN. Drug use and addiction are highly comorbid with psychiatric disorders featuring anhedonia, yet effects of LBN on drug-seeking behavior and the reward and stress-related circuits that underlie it remain unknown. Here we examined the effects of LBN on cocaine intake and seeking, using a battery of behavioral tests measuring distinct aspects of cocaine reward, and for comparison, chocolate intake. We also examined activation of neurons within the pleasure/reward and stress circuits following cocaine in LBN and control rats. Early-life adversity reduced spontaneous intake of palatable chocolate, extending prior reports of sucrose and social-play anhedonia. In a within-session cocaine behavioral economic test, LBN rats self-administered lower dosages of cocaine under low-effort conditions, consistent with a reduced hedonic set-point for cocaine, and potentially anhedonia. In contrast, cocaine demand elasticity was not consistently affected, indicating no major changes in motivation to maintain preferred cocaine blood levels. These changes were selective, as LBN did not cause an overt anxiety-like phenotype, nor did it affect sensitivity to self-administered cocaine dose, responding for cocaine under extinction conditions, cocaine- or cue-induced reinstatement of cocaine seeking, or locomotor response to acute cocaine. However, high Fos expression was seen after cocaine in both reward- and stress-related brain regions of LBN rats, including nucleus accumbens core, central amygdala, and lateral habenula. In contrast, hypothalamic orexin neuron activation after cocaine was significantly attenuated in LBN rats. Together, these findings demonstrate

  2. Early inflammatory changes in radiation-induced oral mucositis. Effect of pentoxifylline in a mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, Sylvia; Bozsaky, Eva; Roitinger, Eva; Schwarz, Karoline [Medical University/AKH Vienna, Applied and Translational Radiobiology, Dept. Radiation Oncology/CD Lab. Med. Radiation Research for Radiation Oncology, Vienna (Austria); Schmidt, Margret [Technische Universitaet Dresden, Dept. Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany); Technische Universitaet Dresden, Helmholtz-Zentrum Dresden - Rossendorf, OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany); Doerr, Wolfgang [Medical University/AKH Vienna, Applied and Translational Radiobiology, Dept. Radiation Oncology/CD Lab. Med. Radiation Research for Radiation Oncology, Vienna (Austria); Technische Universitaet Dresden, Dept. Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany); Technische Universitaet Dresden, Helmholtz-Zentrum Dresden - Rossendorf, OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden (Germany)

    2017-06-15

    Early inflammation is a major factor of mucosal reactions to radiotherapy. Pentoxifylline administration resulted in a significant amelioration of radiation-induced oral mucositis in the mouse tongue model. The underlying mechanisms may be related to the immunomodulatory properties of the drug. The present study hence focuses on the manifestation of early inflammatory changes in mouse tongue during daily fractionated irradiation and their potential modulation by pentoxifylline. Daily fractionated irradiation with 5 fractions of 3 Gy/week (days 0-4, 7-11) was given to the snouts of mice. Groups of 3 animals per day were euthanized every second day between day 0 and 14. Pentoxifylline (15 mg/kg, s. c.) was administered daily from day 5 to the day before sacrifice. The expression of the inflammatory proteins TNFα, NF-κB, and IL-1β were analysed. Fractionated irradiation increased the expression of all inflammatory markers. Pentoxifylline significantly reduced the expression of TNFα and IL-1β, but not NF-κB. Early inflammation, as indicated by the expression of the inflammatory markers TNFα, NF-κB, and IL-1β, is an essential component of early radiogenic oral mucositis. Pentoxifylline differentially modulated the expression of different inflammatory markers. The mucoprotective effect of pentoxifylline does not appear to be based on modulation of NF-κB-associated inflammation. (orig.) [German] Fruehe entzuendliche Veraenderungen sind ein bedeutender Faktor waehrend der Strahlenreaktion der Schleimhaut. Die Behandlung mit Pentoxifyllin erzielte eine signifikante Minderung strahleninduzierter oraler Mukositis im Mauszungenmodel. Die zugrundeliegenden Mechanismen sind potenziell auf die immunomodulatorischen Eigenschaften des Wirkstoffs zurueckzufuehren. Die vorliegenden Untersuchungen fokussieren daher auf die Manifestation frueher entzuendlicher Veraenderungen in der Mauszunge waehrend taeglich fraktionierter Bestrahlung und deren potenzieller Modifikation

  3. The effect of short-term vitamin E against radioiodine-induced early lacrimal gland damage

    International Nuclear Information System (INIS)

    Acar, Ugur; Atilgan, Hasan Ikbal; Acar, Damla Erginturk; Yalniz-Akkaya, Zuleyha; Korkmaz, Meliha; Koca, Goekhan; Yumusak, Nihat

    2013-01-01

    Radioiodine (RAI) is a well-known radionuclide which is used in vivo both for diagnostic and therapeutic purposes, particularly for the treatment of hyperthyroidism and thyroid cancer. Vitamin E is a well-known antioxidant vitamin. The aim of this study was to evaluate whether there was a protective effect of short-term vitamin E on RAI-induced lacrimal gland early damage in experimental animal models. Twentyfour rats were randomly divided into two groups. The first group (RAI group) was administreted 3 mCi 131 I by gastric gavage and 1 mL physiological saline intraperitoneally. The second group (RAI+Vitamin E) was administrated 3 mCi 131 I by gastric gavage and 1 mL vitamin E intraperitoneally. After 24 h of the last dose being administered on the 7th day, the animals were decapitated. The lacrimal glands [Intraorbital (IG), extraorbital (EG) and harderian glands (HG)] of the rats were removed for histopathological examination. Periductal and/or periacinar fibrosis in all lacrimal glands were observed to be statistically significantly less frequent in the RAI + Vitamin E group compared to the RAI group. The existence of the abnormal lobular pattern and peripheral basophilia and irregular nucleus shape in IG and in EG, the poorly defined acidophilic cell outline and periductal infiltration in IG and in HG were observed to be statistically significantly less frequent in the RAI + Vitamin E group than in the RAI group. According to study results, histopathological examinations revealed that vitamin E protects rat lacrimal glands against RAI-related early damage. (author)

  4. An improved method of early diagnosis of smoking-induced respiratory changes using machine learning algorithms.

    Science.gov (United States)

    Amaral, Jorge L M; Lopes, Agnaldo J; Jansen, José M; Faria, Alvaro C D; Melo, Pedro L

    2013-12-01

    The purpose of this study was to develop an automatic classifier to increase the accuracy of the forced oscillation technique (FOT) for diagnosing early respiratory abnormalities in smoking patients. The data consisted of FOT parameters obtained from 56 volunteers, 28 healthy and 28 smokers with low tobacco consumption. Many supervised learning techniques were investigated, including logistic linear classifiers, k nearest neighbor (KNN), neural networks and support vector machines (SVM). To evaluate performance, the ROC curve of the most accurate parameter was established as baseline. To determine the best input features and classifier parameters, we used genetic algorithms and a 10-fold cross-validation using the average area under the ROC curve (AUC). In the first experiment, the original FOT parameters were used as input. We observed a significant improvement in accuracy (KNN=0.89 and SVM=0.87) compared with the baseline (0.77). The second experiment performed a feature selection on the original FOT parameters. This selection did not cause any significant improvement in accuracy, but it was useful in identifying more adequate FOT parameters. In the third experiment, we performed a feature selection on the cross products of the FOT parameters. This selection resulted in a further increase in AUC (KNN=SVM=0.91), which allows for high diagnostic accuracy. In conclusion, machine learning classifiers can help identify early smoking-induced respiratory alterations. The use of FOT cross products and the search for the best features and classifier parameters can markedly improve the performance of machine learning classifiers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Fall in thyroid stimulating hormone (TSH) may be an early marker of ipilimumab-induced hypophysitis.

    Science.gov (United States)

    De Sousa, Sunita M C; Sheriff, Nisa; Tran, Chau H; Menzies, Alexander M; Tsang, Venessa H M; Long, Georgina V; Tonks, Katherine T T

    2018-06-01

    Hypophysitis develops in up to 19% of melanoma patients treated with ipilimumab, a cytotoxic T-lymphocyte antigen-4 antibody. Early detection may avert life-threatening hypopituitarism. We aimed to assess the incidence of ipilimumab-induced hypophysitis (IH) at a quaternary melanoma referral centre, and to determine whether cortisol or thyroid stimulating hormone (TSH) monitoring could predict IH onset. We performed a retrospective cohort study of ipilimumab-treated patients at a quaternary melanoma referral centre in Australia. The inclusion criteria were patients with metastatic or unresectable melanoma treated with ipilimumab monotherapy, and cortisol and TSH measurements prior to ≥ 2 infusions. The main outcomes were IH incidence and TSH and cortisol patterns in patients who did and did not develop IH. Of 78 ipilimumab-treated patients, 46 met the study criteria and 9/46 (20%) developed IH at a median duration of 13.0 weeks (range 7.7-18.1) following ipilimumab initiation. All patients whose TSH fell ≥ 80% compared to baseline developed IH, and, in 5/9 patients with IH, TSH fell prior to cortisol fall and IH diagnosis. Pre-cycle-4 TSH was significantly lower in those who developed IH (0.31 vs. 1.73 mIU/L, P = 0.006). TSH fall was detected at a median time of 9.2 (range 7.7-16.4) weeks after commencing ipilimumab, and a median of 3.6 (range of - 1.4 to 9.7) weeks before IH diagnosis. There was no difference in TSH between the groups before cycles 1-3 or in cortisol before cycles 1-4. TSH fall ≥ 80% may be an early marker of IH. Serial TSH measurement during ipilimumab therapy may be an inexpensive tool to expedite IH diagnosis.

  6. Analysis of early initiating event(s) in radiation-induced thymic lymphomagenesis

    International Nuclear Information System (INIS)

    Muto, Masahiro; Ying Chen; Kubo, Eiko; Mita, Kazuei

    1996-01-01

    Since the T cell receptor rearrangement is a sequential process and unique to the progeny of each clone, we investigated the early initiating events in radiation-induced thymic lymphomagenesis by comparing the oncogenic alterations with the pattern of γ T cell receptor (TCR) rearrangements. We reported previously that after leukemogenic irradiation, preneoplastic cells developed, albeit infrequently, from thymic leukemia antigen-2 + (TL-2 + ) thymocytes. Limited numbers of TL-2 + cells from individual irradiated B10.Thy-1.1 mice were injected into B10.Thy-1.2 mice intrathymically, and the common genetic changes among the donor-type T cell lymphomas were investigated with regard to p53 gene and chromosome aberrations. The results indicated that some mutations in the p53 gene had taken place in these lymphomas, but there was no common mutation among the donor-type lymphomas from individual irradiated mice, suggesting that these mutations were late-occurring events in the process of oncogenesis. On the other hand, there were common chromosome aberrations or translocations such as trisomy 15, t(7F; 10C), t(1A; 13D) or t(6A; XB) among the donor-type lymphomas derived from half of the individual irradiated mice. This indicated that the aberrations/translocations, which occurred in single progenitor cells at the early T cell differentiation either just before or after γ T cell receptor rearrangements, might be important candidates for initiating events. In the donor-type lymphomas from the other half of the individual irradiated mice, microgenetic changes were suggested to be initial events and also might take place in single progenitor cells just before or right after γ TCR rearrangements. (author)

  7. Social defeat during adolescence and adulthood differentially induce BDNF-regulated immediate early genes

    Directory of Open Access Journals (Sweden)

    Caroline M. Coppens

    2011-11-01

    Full Text Available Stressful life events generally enhance the vulnerability for the development of human psychopathologies such as anxiety disorders and depression. The incidence rates of adult mental disorders steeply rises during adolescence in parallel with a structural and functional reorganization of the neural circuitry underlying stress reactivity. However, the mechanisms underlying susceptibility to stress and manifestation of mental disorders during adolescence are little understood. We hypothesized that heightened sensitivity to stress during adolescence reflects age-dependent differences in the expression of activity-dependent genes involved in synaptic plasticity. Therefore, we compared the effect of social stress during adolescence with social stress in adulthood on the expression of a panel of genes linked to induction of long-term potentiation (LTP and brain-derived neurotrophic factor (BDNF signaling. We show that social defeat during adolescence and adulthood differentially regulates expression of the immediate early genes BDNF, Arc, Carp, and Tieg1, as measured by qPCR in tissue lysates from prefrontal cortex, nucleus accumbens, and hippocampus. In the hippocampus, mRNA levels for all four genes were robustly elevated following social defeat in adolescence, whereas none were induced by defeat in adulthood. The relationship to coping style was also examined using adult reactive and proactive coping rats. Gene expression levels of reactive and proactive animals were similar in the prefrontal cortex and hippocampus. However, a trend toward a differential expression of BDNF and Arc mRNA in the nucleus accumbens was detected. BDNF mRNA was increased in the nucleus accumbens of proactive defeated animals, whereas the expression level in reactive defeated animals was comparable to control animals. The results demonstrate striking differences in immediate early gene expression in response to social defeat in adolescent and adult rats.

  8. Characterizing the protocol for early modified constraint-induced movement therapy in the EXPLICIT-stroke trial

    NARCIS (Netherlands)

    Nijland, R van; Wegen, E. van; Krogt, H. van der; Bakker, C.D.; Buma, F.; Klomp, A.; Kordelaar, J. van; Kwakkel, G.; Geurts, A.C.; Kuijk, A.A. van; Lindeman, E.; Visser-Meily, J.M.A.; Arendzen, H.J.; Meskers, C.G.; Helm, F.C.T. van der; Vlugt, E. de

    2013-01-01

    Constraint-induced movement therapy (CIMT) is a commonly used rehabilitation intervention to improve upper limb function after stroke. CIMT was originally developed for patients with a chronic upper limb paresis. Although there are indications that exercise interventions should start as early as

  9. Interleukin 1 induces early protein phosphorylation and requires only a short exposure for late induced secretion of β-endorphin in a mouse pituitary cell line

    International Nuclear Information System (INIS)

    Fagarasan, M.O.; Axelrod, J.; Bishop, J.F.; Rinaudo, M.S.

    1990-01-01

    Previous work has shown that prolonged pretreatment of a mouse anterior pituitary cell line, AtT-20 cells, with the cytokine interleukin 1 (IL-1) stimulates β-endorphin release and potentiates the secretion induced by many secretagogues. Desensitization of protein kinase C (PKC) by pretreatment with phorbol ester [phorbol 12-tetradecanoate 13-acetate (TPA)] for 8 hr abolished the secretion induced by TPA as well as the enhancement of TPA-induced β-endorphin release produced by IL-1. Desensitization of PKC only partly abolished the potentiating effects of IL-1 on corticotropin-releasing factor-induced β-endorphin secretion. In contrast, IL-1-induced β-endorphin release was independent of PKC. The authors observed that treatment of AtT-20 cells with IL-1 markedly phosphorylated 19-, 20-, and 60-kDa proteins within minutes, presumably by early activation of protein kinases. Prolonged treatment with TPA, which was shown to desensitize an 87-kDa protein (a substrate for PKC), had no effect on IL-1-induced phosphorylation of 20-, 60-, and 87-kDa proteins, indicating that the phosphorylation of these proteins does not involve PKC. IL-1 does not generate cAMP in AtT-20 cells, suggesting that a cAMP-dependent protein kinase is also not involved. These observations indicate that once IL-1 generates an early signal, its presence is no longer necessary for the subsequent secretion of β-endorphin

  10. Exploring the early stages of the pH-induced conformational change of influenza hemagglutinin.

    Science.gov (United States)

    Zhou, Yu; Wu, Chao; Zhao, Lifeng; Huang, Niu

    2014-10-01

    Hemagglutinin (HA) mediates the membrane fusion process of influenza virus through its pH-induced conformational change. However, it remains challenging to study its structure reorganization pathways in atomic details. Here, we first applied continuous constant pH molecular dynamics approach to predict the pK(a) values of titratable residues in H2 subtype HA. The calculated net-charges in HA1 globular heads increase from 0e (pH 7.5) to +14e (pH 4.5), indicating that the charge repulsion drives the detrimerization of HA globular domains. In HA2 stem regions, critical pH sensors, such as Glu103(2), His18(1), and Glu89(1), are identified to facilitate the essential structural reorganizations in the fusing pathways, including fusion peptide release and interhelical loop transition. To probe the contribution of identified pH sensors and unveil the early steps of pH-induced conformational change, we carried out conventional molecular dynamics simulations in explicit water with determined protonation state for each titratable residue in different environmental pH conditions. Particularly, energy barriers involving previously uncharacterized hydrogen bonds and hydrophobic interactions are identified in the fusion peptide release pathway. Nevertheless, comprehensive comparisons across HA family members indicate that different HA subtypes might employ diverse pH sensor groups along with different fusion pathways. Finally, we explored the fusion inhibition mechanism of antibody CR6261 and small molecular inhibitor TBHQ, and discovered a novel druggable pocket in H2 and H5 subtypes. Our results provide the underlying mechanism for the pH-driven conformational changes and also novel insight for anti-flu drug development. © 2014 Wiley Periodicals, Inc.

  11. Comparative molecular analysis of early and late cancer cachexia-induced muscle wasting in mouse models.

    Science.gov (United States)

    Sun, Rulin; Zhang, Santao; Lu, Xing; Hu, Wenjun; Lou, Ning; Zhao, Yan; Zhou, Jia; Zhang, Xiaoping; Yang, Hongmei

    2016-12-01

    Cancer-induced muscle wasting, which commonly occurs in cancer cachexia, is characterized by impaired quality of life and poor patient survival. To identify an appropriate treatment, research on the mechanism underlying muscle wasting is essential. Thus far, studies on muscle wasting using cancer cachectic models have generally focused on early cancer cachexia (ECC), before severe body weight loss occurs. In the present study, we established models of ECC and late cancer cachexia (LCC) and compared different stages of cancer cachexia using two cancer cachectic mouse models induced by colon-26 (C26) adenocarcinoma or Lewis lung carcinoma (LLC). In each model, tumor-bearing (TB) and control (CN) mice were injected with cancer cells and PBS, respectively. The TB and CN mice, which were euthanized on the 24th day or the 36th day after injection, were defined as the ECC and ECC-CN mice or the LCC and LCC-CN mice. In addition, the tissues were harvested and analyzed. We found that both the ECC and LCC mice developed cancer cachexia. The amounts of muscle loss differed between the ECC and LCC mice. Moreover, the expression of some molecules was altered in the muscles from the LCC mice but not in those from the ECC mice compared with their CN mice. In conclusion, the molecules with altered expression in the muscles from the ECC and LCC mice were not exactly the same. These findings may provide some clues for therapy which could prevent the muscle wasting in cancer cachexia from progression to the late stage.

  12. Early-life viral infection and allergen exposure interact to induce an asthmatic phenotype in mice

    Directory of Open Access Journals (Sweden)

    Asquith Kelly L

    2010-02-01

    Full Text Available Abstract Background Early-life respiratory viral infections, notably with respiratory syncytial virus (RSV, increase the risk of subsequent development of childhood asthma. The purpose of this study was to assess whether early-life infection with a species-specific model of RSV and subsequent allergen exposure predisposed to the development of features of asthma. Methods We employed a unique combination of animal models in which BALB/c mice were neonatally infected with pneumonia virus of mice (PVM, which replicates severe RSV disease in human infants and following recovery, were intranasally sensitised with ovalbumin. Animals received low-level challenge with aerosolised antigen for 4 weeks to elicit changes of chronic asthma, followed by a single moderate-level challenge to induce an exacerbation of inflammation. We then assessed airway inflammation, epithelial changes characteristic of remodelling, airway hyperresponsiveness (AHR and host immunological responses. Results Allergic airway inflammation, including recruitment of eosinophils, was prominent only in animals that had recovered from neonatal infection with PVM and then been sensitised and chronically challenged with antigen. Furthermore, only these mice exhibited an augmented Th2-biased immune response, including elevated serum levels of anti-ovalbumin IgE and IgG1 as well as increased relative expression of Th2-associated cytokines IL-4, IL-5 and IL-13. By comparison, development of AHR and mucous cell change were associated with recovery from PVM infection, regardless of subsequent allergen challenge. Increased expression of IL-25, which could contribute to induction of a Th2 response, was demonstrable in the lung following PVM infection. Signalling via the IL-4 receptor α chain was crucial to the development of allergic inflammation, mucous cell change and AHR, because all of these were absent in receptor-deficient mice. In contrast, changes of remodelling were evident in mice

  13. Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos.

    Science.gov (United States)

    Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Rivière, Guillaume

    2018-03-01

    Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L -1 Cu 2+ ) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval bioassay at the D-larva stage 24 h post fertilization (hpf) and genotoxicity at gastrulation 7 hpf. In parallel, the relative expression of 15 genes encoding putative homeotic, biomineralization and DNA methylation proteins was measured at three developmental stages (3 hpf morula stage, 7 hpf gastrula stage, 24 hpf D-larvae stage) using RT-qPCR. Global DNA content in methylcytosine and hydroxymethylcytosine were measured by HPLC and gene-specific DNA methylation levels were monitored using MeDIP-qPCR. A significant increase in larval abnormalities was observed from copper concentrations of 10 μg L -1 , while significant genotoxic effects were detected at 1 μg L -1 and above. All the selected genes presented a stage-dependent expression pattern, which was impaired for some homeobox and DNA methylation genes (Notochord, HOXA1, HOX2, Lox5, DNMT3b and CXXC-1) after copper exposure. While global DNA methylation (5-methylcytosine) at gastrula stage didn't show significant changes between experimental conditions, 5-hydroxymethylcytosine, its degradation product, decreased upon copper treatment. The DNA methylation of exons and the transcript levels were correlated in control samples for HOXA1 but such

  14. Challenges for operational forecasting and early warning of rainfall induced landslides

    Science.gov (United States)

    Guzzetti, Fausto

    2017-04-01

    In many areas of the world, landslides occur every year, claiming lives and producing severe economic and environmental damage. Many of the landslides with human or economic consequences are the result of intense or prolonged rainfall. For this reason, in many areas the timely forecast of rainfall-induced landslides is of both scientific interest and social relevance. In the recent years, there has been a mounting interest and an increasing demand for operational landslide forecasting, and for associated landslide early warning systems. Despite the relevance of the problem, and the increasing interest and demand, only a few systems have been designed, and are currently operated. Inspection of the - limited - literature on operational landslide forecasting, and on the associated early warning systems, reveals that common criteria and standards for the design, the implementation, the operation, and the evaluation of the performances of the systems, are lacking. This limits the possibility to compare and to evaluate the systems critically, to identify their inherent strengths and weaknesses, and to improve the performance of the systems. Lack of common criteria and of established standards can also limit the credibility of the systems, and consequently their usefulness and potential practical impact. Landslides are very diversified phenomena, and the information and the modelling tools used to attempt landslide forecasting vary largely, depending on the type and size of the landslides, the extent of the geographical area considered, the timeframe of the forecasts, and the scope of the predictions. Consequently, systems for landslide forecasting and early warning can be designed and implemented at several different geographical scales, from the local (site or slope specific) to the regional, or even national scale. The talk focuses on regional to national scale landslide forecasting systems, and specifically on operational systems based on empirical rainfall threshold

  15. One-point functions of non-SUSY operators at arbitrary genus in a matrix model for type IIA superstrings

    Directory of Open Access Journals (Sweden)

    Tsunehide Kuroki

    2017-06-01

    Full Text Available In the previous paper, the authors pointed out correspondence between a supersymmetric double-well matrix model and two-dimensional type IIA superstring theory on a Ramond–Ramond background from the viewpoint of symmetry and spectrum. This was confirmed by agreement between planar correlation functions in the matrix model and tree-level amplitudes in the superstring theory. In order to investigate the correspondence further, in this paper we compute correlation functions to all order of genus expansion in the double scaling limit of the matrix model. One-point functions of operators protected by supersymmetry terminate at some finite order, whereas those of unprotected operators yield non-Borel summable series. The behavior of the latter is characteristic in string perturbation series, providing further evidence that the matrix model describes a string theory. Moreover, instanton corrections to the planar one-point functions are also computed, and universal logarithmic scaling behavior is found for non-supersymmetric operators.

  16. Lactobacillus salivarius Ren prevent the early colorectal carcinogenesis in 1, 2-dimethylhydrazine-induced rat model.

    Science.gov (United States)

    Zhu, J; Zhu, C; Ge, S; Zhang, M; Jiang, L; Cui, J; Ren, F

    2014-07-01

    The objective of this study was to investigate the impact of Lactobacillus salivarius Ren (LS) on modulating colonic micro flora structure and influencing host colonic health in a rat model with colorectal precancerous lesions. Male F344 rats were injected with 1, 2-dimethylhydrazine (DMH) and treated with LS of two doses (5 × 10(8) and 1 × 10(10) CFU kg(-1) body weight) for 15 weeks. The colonic microflora profiles, luminal metabolites, epithelial proliferation and precancerous lesions [aberrant crypt foci (ACF)] were determined. A distinct segregation of colonic microflora structures was observed in LS-treated group. The abundance of one Prevotella-related strain was increased, and the abundance of one Bacillus-related strain was decreased by LS treatment. These changes were accompanied by increased short-chain fatty acid levels and decreased azoreductase activity. LS treatment also reduced the number of ACF by c. 40% and suppressed epithelial proliferation. Lactobacillus salivarius Ren improved the colonic microflora structures and the luminal metabolisms in addition preventing the early colorectal carcinogenesis in DMH-induced rat model. Colonic microflora is an important factor in colorectal carcinogenesis. Modulating the structural shifts of microflora may provide a novel option for preventing colorectal carcinogenesis. This study suggested a potential probiotic-based approach to modulate the intestinal microflora in the prevention of colorectal carcinogenesis. © 2014 The Society for Applied Microbiology.

  17. Early transcriptional alteration of histone deacetylases in a murine model of doxorubicin-induced cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Izabela Piotrowska

    Full Text Available Doxorubicin is a potent chemotherapeutic agent that is widely-used to treat a variety of cancers but causes acute and chronic cardiac injury, severely limiting its use. Clinically, the acute side effects of doxorubicin are mostly manageable, whereas the delayed consequences can lead to life-threatening heart failure, even decades after cancer treatment. The cardiotoxicity of doxorubicin is subject to a critical cumulative dose and so dosage limitation is considered to be the best way to reduce these effects. Hence, a number of studies have defined a "safe dose" of the drug, both in animal models and clinical settings, with the aim of avoiding long-term cardiac effects. Here we show that a dose generally considered as safe in a mouse model can induce harmful changes in the myocardium, as early as 2 weeks after infusion. The adverse changes include the development of fibrotic lesions, disarray of cardiomyocytes and a major transcription dysregulation. Importantly, low-dose doxorubicin caused specific changes in the transcriptional profile of several histone deacetylases (HDACs which are epigenetic regulators of cardiac remodelling. This suggests that cardioprotective therapies, aimed at modulating HDACs during doxorubicin treatment, deserve further exploration.

  18. Role of MMP-12 on tissue remodeling at early stage of radiation-induced pulmonary injury

    International Nuclear Information System (INIS)

    Li Ming; Song Liangwen; Diao Ruiying; Wang Shaoxia; Xu Xinping; Luo Qingliang

    2008-01-01

    Objective: To explore the role of MMP-12 on tissue remodeling at early stage of radiation- induced pulmonary injury. Methods: Wistar rats irradiated by 60 Co γ-rays to the whole lungs were sacrificed at 1, 2, 4 weeks. MMP-12 mRNA expression was detected by RT-PCR. MMP-2, MMP-9, MMP-12 activities were determined by zymography. The degradation and collapse of elastin were determined by tissue elastin particular staining; the 'cross talking' phenomenon between alveolar type II cells and mesenchymal cells was observed under electron microscope; the expression of TGF-β1 and TNF-α in BALF was detected by ELISA. The expression of α-SMA was determined by immunohistochemistry. Results: The mRNA expression of MMP-12 displayed a significant elevation at 1, 2, 4 weeks after irradiation. MMP-12 activity increased at 2, 4 weeks after irradiation. Elastin began to degrade and collapse at 1 week, which became worst 4 weeks after irradiation. The cross talking phenomenon was found under electron microscope. The expression of TGF-β1, TNF-α and α-SMA was increased gradually as time elapse after irradiation. Conclusions: 60 Co γ-ray irradiation can promote pulmonary MMP-12 expression, initiate pulmonary tissue remodeling by degradation of elastin, and make the pulmonary injury develop towards pulmonary fibrosis eventually. (authors)

  19. Trophic level stability-inducing effects of predaceous early juvenile fish in an estuarine mesocosm study.

    Directory of Open Access Journals (Sweden)

    Ryan J Wasserman

    Full Text Available Classically, estuarine planktonic research has focussed largely on the physico-chemical drivers of community assemblages leaving a paucity of information on important biological interactions.Within the context of trophic cascades, various treatments using in situ mesocosms were established in a closed estuary to highlight the importance of predation in stabilizing estuarine plankton abundances. Through either the removal (filtration or addition of certain planktonic groups, five different trophic systems were established. These treatments contained varied numbers of trophic levels and thus different "predators" at the top of the food chain. The abundances of zooplankton (copepod and polychaete, ciliate, micro-flagellate, nano-flagellate and bacteria were investigated in each treatment, over time. The reference treatment containing apex zooplanktivores (early juvenile mullet and plankton at natural densities mimicked a natural, stable state of an estuary. Proportional variability (PV and coefficient of variation (CV of temporal abundances were calculated for each taxon and showed that apex predators in this experimental ecosystem, when compared to the other systems, induced stability. The presence of these predators therefore had consequences for multiple trophic levels, consistent with trophic cascade theory.PV and CV proved useful indices for comparing stability. Apex predators exerted a stabilizing pressure through feeding on copepods and polychaetes which cascaded through the ciliates, micro-flagellates, nano-flagellates and bacteria. When compared with treatments without apex predators, the role of predation in structuring planktonic communities in closed estuaries was highlighted.

  20. A study on early microstructural changes in the rabbit gallbladder induced by shock waves

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eun Oak [Hong-Sung Koryo Hospital, Hongsung (Korea, Republic of); Shim, Hyung Jin; Kim, Kun Sang; Ryo, Dae Sik; Choi, Yun Sun; Song, In Sup; Kim, Young Koo [College of Medicine, Chung Ang University, Seoul (Korea, Republic of)

    1994-05-15

    In order to evaluate microstructural changes after shock wave exposure, gross, light microscopic and transmission electron microscopic findings were analyzed with rabbit gallbladders. A preliminary study(2 rabbits) was performed to determine the dosage intensity of shock waves needed to inflict damage, using a EDAP LT 01 piezoelectric extracorporeal shock wave lothotriptor. The Gallbladders of three different groups of rabbits were given shock waves of various intensity. A storage value of 100, 50, 25 at rate of 20/sec under 80% power were given to group I (4 rabbits), group II (4 rabbits), and group III (3 rabbits), respectively. The rabbits were sacrificed 6-12 hours later. The observed pathologic changes in the transmission electron microscopy were vaculization of cytoplasm and swelling of epithelial cells with dilatation and structural alteration of intracellular organelles, especially endoplasmic reticulum. Cell membrane rupture and necrosis were observed at the markedly affected area. The structural changes of intracellular organelles were minimally found at a storage value of 25. However, above pathologic changes with dilatation and structural alterations of endoplasmic reticulums were more profound at value of 100. Early histologic changes induced by shocked waves are dose dependent and findings of cellular damage caused by ESWL might be explained as above.

  1. Autophagic degradation of aquaporin-2 is an early event in hypokalemia-induced nephrogenic diabetes insipidus.

    Science.gov (United States)

    Khositseth, Sookkasem; Uawithya, Panapat; Somparn, Poorichaya; Charngkaew, Komgrid; Thippamom, Nattakan; Hoffert, Jason D; Saeed, Fahad; Michael Payne, D; Chen, Shu-Hui; Fenton, Robert A; Pisitkun, Trairak

    2015-12-17

    Hypokalemia (low serum potassium level) is a common electrolyte imbalance that can cause a defect in urinary concentrating ability, i.e., nephrogenic diabetes insipidus (NDI), but the molecular mechanism is unknown. We employed proteomic analysis of inner medullary collecting ducts (IMCD) from rats fed with a potassium-free diet for 1 day. IMCD protein quantification was performed by mass spectrometry using a label-free methodology. A total of 131 proteins, including the water channel AQP2, exhibited significant changes in abundance, most of which were decreased. Bioinformatic analysis revealed that many of the down-regulated proteins were associated with the biological processes of generation of precursor metabolites and energy, actin cytoskeleton organization, and cell-cell adhesion. Targeted LC-MS/MS and immunoblotting studies further confirmed the down regulation of 18 selected proteins. Electron microscopy showed autophagosomes/autophagolysosomes in the IMCD cells of rats deprived of potassium for only 1 day. An increased number of autophagosomes was also confirmed by immunofluorescence, demonstrating co-localization of LC3 and Lamp1 with AQP2 and several other down-regulated proteins in IMCD cells. AQP2 was also detected in autophagosomes in IMCD cells of potassium-deprived rats by immunogold electron microscopy. Thus, enhanced autophagic degradation of proteins, most notably including AQP2, is an early event in hypokalemia-induced NDI.

  2. Skeletal and dental changes induced by bionator in early treatment of class II

    Directory of Open Access Journals (Sweden)

    Dirceu Barnabé Raveli

    2016-09-01

    Full Text Available The purpose was to investigate the amount of skeletal and dentoalveolar changes after early treatment of Class II, Division 1 malocclusion with bionator appliance in prepubertal growing patients. Forty Class II patients were divided in two groups. Treated group consisted of 20 subjects treated consecutively with bionator. Mean age at the start of treatment (T0 was 9.1 years, while it was 10.6 years at the end of treatment (T1. Mean treatment time was 17.7 months. Pretreatment and post-treatment cephalometric records of treated group were evaluated and compared with a control group consisted of 20 patients with untreated Class II malocclusion. Intergroup comparisons were performed using Student’s t-tests and chi-square test with Yates’ correction at a significance level of 5 per cent. Bionator appliance was effective in generating differential growth between the jaws. Cephalometric skeletal measurements ANB, WITS, Lafh, Co-A and dental L6-Mp, U1.Pp, IsIi, OB, OJ showed statistically significantly different from the control. Bionator induced more dentoalveolar changes than skeletal during treatment in prepubertal stage.

  3. Reduced Cu(InGa)Se2 Thickness in Solar Cells Using a Superstrate Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Shafarman, William N. [Univ. of Delaware, Newark, DE (United States)

    2015-03-30

    This project by the Institute of Energy Conversion (IEC) and the Department of Electrical and Computer Engineering at the University of Delaware sought to develop the technology and underlying science to enable reduced cost of Cu(InGa)Se2 manufacturing by reducing the thickness of the Cu(InGa)Se2 absorber layer by half compared to typical production. The approach to achieve this was to use the superstrate cell configuration in which light is incident on the cell through the glass. This structure facilitates optical enhancement approaches needed to achieve high efficiency with Cu(InGa)Se2 thicknesses less than 1 µm. The primary objective was to demonstrate a Cu(InGa)Se2 cell with absorber thickness 0.5 - 0.7 µm and 17% efficiency, along with a quantitative loss analysis to define a pathway to 20% efficiency. Additional objectives were the development of stable TCO and buffer layers or contact layers to withstand the Cu(InGa)Se2 deposition temperature and of advanced optical enhancement methods. The underlying fundamental science needed to effectively transition these outcomes to large scale was addressed by extensive materials and device characterization and by development of comprehensive optical models. Two different superstrate configurations have been investigated. A frontwall cell is illuminated through the glass to the primary front junction of the device. This configuration has been used for previous efforts on superstrate Cu(InGa)Se2 but performance has been limited by interdiffusion or reaction with CdS or other buffer layers. In this project, several approaches to overcome these limitations were explored using CdS, ZnO and ZnSe buffer layers. In each case, mechanisms that limit device performance were identified using detailed characterization of the materials and junctions. Due to the junction formation difficulties, efforts were concentrated on a new backwall configuration in which light

  4. Modulation of early stress-induced neurobiological changes: a review of behavioural and pharmacological interventions in animal models.

    Science.gov (United States)

    Harrison, E L; Baune, B T

    2014-05-13

    Childhood adversity alters the predisposition to psychiatric disorders later in life. Those with psychiatric conditions and a history of early adversity exhibit a higher incidence of treatment resistance compared with individuals with no such history. Modulation of the influence early stress exerts over neurobiology may help to prevent the development of psychiatric disorders in some cases, while attenuating the extent of treatment resistance in those with established psychiatric disorders. This review aims to critically evaluate the ability of behavioural, environmental and pharmacologic interventions to modulate neurobiological changes induced by early stress in animal models. Databases were systematically searched to locate literature relevant to this review. Early adversity was defined as stress that resulted from manipulation of the mother-infant relationship. Analysis was restricted to animal models to enable characterisation of how a given intervention altered specific neurobiological changes induced by early stress. A wide variety of changes in neurobiology due to early stress are amenable to intervention. Behavioural interventions in childhood, exercise in adolescence and administration of epigenetic-modifying drugs throughout life appear to best modulate cellar and behavioural alterations induced by childhood adversity. Other pharmacotherapies, such as endocannabinoid system modulators, anti-inflammatories and antidepressants can also influence these neurobiological and behavioural changes that result from early stress, although findings are less consistent at present and require further investigation. Further work is required to examine the influence that behavioural interventions, exercise and epigenetic-modifying drugs exert over alterations that occur following childhood stress in human studies, before possible translational into clinical practice is possible.

  5. Enhanced adhesion of early endothelial progenitor cells to radiation-induced senescence-like vascular endothelial cells in vitro

    International Nuclear Information System (INIS)

    Sermsathanasawadi, N.; Inoue, Yoshinori; Iwai, Takehisa; Ishii, Hideto; Yoshida, Masayuki; Igarashi, Kaori; Miura, Masahiko

    2009-01-01

    The effects of ionizing radiation (IR) on tumor neovascularization are still unclear. We previously reported that vascular endothelial cells (ECs) expressing the IR-induced senescence-like (IRSL) phenotype exhibit a significant decrease in angiogenic activity in vitro. In this study, we examined the effects of the IRSL phenotype on adhesion to early endothelial progenitor cells (early EPCs). Adhesion of human peripheral blood-derived early EPCs to human umbilical vein endothelial cells (HUVECs) expressing the IRSL phenotype was evaluated by an adhesion assay under static conditions. It was revealed that the IRSL HUVECs supported significantly more adhesion of early EPCs than normal HUVECs. Expressions of ICAM-1, VCAM-1 and E-selectin were up-regulated in IRSL HUVECs. Pre-treatment of IRSL HUVECs with adhesion-blocking monoclonal antibodies against E-selectin and VCAM-1 significantly reduced early EPC adhesion to IRSL HUVECs, suggesting a potential role for the E-selectin and VCAM-1 in the adhesion between IRSL ECs and early EPCs. Therefore, the IRSL phenotype expressed in ECs may enhance neovascularization via increased homing of early EPCs. Our findings are first to implicate the complex effects of this phenotype on tumor neovascularization following irradiation. (author)

  6. Hypoperfusion Induced by Preconditioning Treadmill Training in Hyper-Early Reperfusion After Cerebral Ischemia: A Laser Speckle Imaging Study.

    Science.gov (United States)

    He, Zhijie; Lu, Hongyang; Yang, Xiaojiao; Zhang, Li; Wu, Yi; Niu, Wenxiu; Ding, Li; Wang, Guili; Tong, Shanbao; Jia, Jie

    2018-01-01

    Exercise preconditioning induces neuroprotective effects during cerebral ischemia and reperfusion, which involves the recovery of cerebral blood flow (CBF). Mechanisms underlying the neuroprotective effects of re-established CBF following ischemia and reperfusion are unclear. The present study investigated CBF in hyper-early stage of reperfusion by laser speckle contrast imaging, a full-field high-resolution optical imaging technique. Rats with or without treadmill training were subjected to middle cerebral artery occlusion followed by reperfusion. CBF in arteries, veins, and capillaries in hyper-early stage of reperfusion (1, 2, and 3 h after reperfusion) and in subacute stage (24 h after reperfusion) were measured. Neurological scoring and 2,3,5-triphenyltetrazolium chloride staining were further applied to determine the neuroprotective effects of exercise preconditioning. In hyper-early stage of reperfusion, CBF in the rats with exercise preconditioning was reduced significantly in arteries and veins, respectively, compared to rats with no exercise preconditioning. Capillary CBF remained stable in the hyper-early stage of reperfusion, though it increased significantly 24 h after reperfusion in the rats with exercise preconditioning. As a neuroprotective strategy, exercise preconditioning reduced the blood perfusion of arteries and veins in the hyper-early stage of reperfusion, which indicated intervention-induced neuroprotective hypoperfusion after reperfusion onset.

  7. Gene expression profiling reveals underlying molecular mechanisms of the early stages of tamoxifen-induced rat hepatocarcinogenesis

    International Nuclear Information System (INIS)

    Pogribny, Igor P.; Bagnyukova, Tetyana V.; Tryndyak, Volodymyr P.; Muskhelishvili, Levan; Rodriguez-Juarez, Rocio; Kovalchuk, Olga; Han Tao; Fuscoe, James C.; Ross, Sharon A.; Beland, Frederick A.

    2007-01-01

    Tamoxifen is a widely used anti-estrogenic drug for chemotherapy and, more recently, for the chemoprevention of breast cancer. Despite the indisputable benefits of tamoxifen in preventing the occurrence and re-occurrence of breast cancer, the use of tamoxifen has been shown to induce non-alcoholic steatohepatitis, which is a life-threatening fatty liver disease with a risk of progression to cirrhosis and hepatocellular carcinoma. In recent years, the high-throughput microarray technology for large-scale analysis of gene expression has become a powerful tool for increasing the understanding of the molecular mechanisms of carcinogenesis and for identifying new biomarkers with diagnostic and predictive values. In the present study, we used the high-throughput microarray technology to determine the gene expression profiles in the liver during early stages of tamoxifen-induced rat hepatocarcinogenesis. Female Fisher 344 rats were fed a 420 ppm tamoxifen containing diet for 12 or 24 weeks, and gene expression profiles were determined in liver of control and tamoxifen-exposed rats. The results indicate that early stages of tamoxifen-induced liver carcinogenesis are characterized by alterations in several major cellular pathways, specifically those involved in the tamoxifen metabolism, lipid metabolism, cell cycle signaling, and apoptosis/cell proliferation control. One of the most prominent changes during early stages of tamoxifen-induced hepatocarcinogenesis is dysregulation of signaling pathways in cell cycle progression from the G 1 to S phase, evidenced by the progressive and sustained increase in expression of the Pdgfc, Calb3, Ets1, and Ccnd1 genes accompanied by the elevated level of the PI3K, p-PI3K, Akt1/2, Akt3, and cyclin B, D1, and D3 proteins. The early appearance of these alterations suggests their importance in the mechanism of neoplastic cell transformation induced by tamoxifen

  8. Visualization of odor-induced neuronal activity by immediate early gene expression

    Directory of Open Access Journals (Sweden)

    Bepari Asim K

    2012-11-01

    Full Text Available Abstract Background Sensitive detection of sensory-evoked neuronal activation is a key to mechanistic understanding of brain functions. Since immediate early genes (IEGs are readily induced in the brain by environmental changes, tracing IEG expression provides a convenient tool to identify brain activity. In this study we used in situ hybridization to detect odor-evoked induction of ten IEGs in the mouse olfactory system. We then analyzed IEG induction in the cyclic nucleotide-gated channel subunit A2 (Cnga2-null mice to visualize residual neuronal activity following odorant exposure since CNGA2 is a key component of the olfactory signal transduction pathway in the main olfactory system. Results We observed rapid induction of as many as ten IEGs in the mouse olfactory bulb (OB after olfactory stimulation by a non-biological odorant amyl acetate. A robust increase in expression of several IEGs like c-fos and Egr1 was evident in the glomerular layer, the mitral/tufted cell layer and the granule cell layer. Additionally, the neuronal IEG Npas4 showed steep induction from a very low basal expression level predominantly in the granule cell layer. In Cnga2-null mice, which are usually anosmic and sexually unresponsive, glomerular activation was insignificant in response to either ambient odorants or female stimuli. However, a subtle induction of c-fos took place in the OB of a few Cnga2-mutants which exhibited sexual arousal. Interestingly, very strong glomerular activation was observed in the OB of Cnga2-null male mice after stimulation with either the neutral odor amyl acetate or the predator odor 2, 3, 5-trimethyl-3-thiazoline (TMT. Conclusions This study shows for the first time that in vivo olfactory stimulation can robustly induce the neuronal IEG Npas4 in the mouse OB and confirms the odor-evoked induction of a number of IEGs. As shown in previous studies, our results indicate that a CNGA2-independent signaling pathway(s may activate the

  9. ULTRASTRUCTURAL MODIFICATIONS INDUCED BY DIRECT ACTION OF CU2+ UPON EARLY CHICK EMBRYO

    Directory of Open Access Journals (Sweden)

    Delia Checiu

    2003-01-01

    Full Text Available Teratological testing of sulphonate phtalocyanine (an alimentary blue dye synthetized by the Center of Chemisty, Timisoara, shown a strong malformative effect of this compound upon early chick embryo (48 hours of incubation, (Sandor, Checiu, Prelipceanu, 1985. Dye administration on day 2 of incubation (44-48 hours revealed a high rate of embryo mortality and abnormal modification of caudal segment or even a total absence of caudal tail bud. Living embryos until day 7 of incubation showed a normal development of the anterior body part (head and trunk in contrast with posterior body part which presented an abnormal position of posterior limbs, tail and trunk aplasia. The dye with the some name produced in Germany did not show (in the some experimental conditions a malformative effect. The only difference between the two dyes was the presence of Cu2+ in our compound. It is well known that chemicals and physics factors (X rayes, insuline, hypoxy, D-Actinomycine, sucrose, etc. are noxious, inducing malformations of caudal segment (tail bud, urogenital and anorectal abnormalities associated with cardiac, facial and SNC malformations (Landauer 1953, Shepard 1973. Abnormalities of esophagus, urogenital and anorectal region associated with those of caudal axial skeleton and posterior limb buds are involved in caudal dysplasia syndrome (Duhamel 1961 cited by Roux and Martinet 1962. This syndrome is frequent (1:1000 in children of diabetic mothers (Warkany 1971. Experimental works on mice suggested implication of genetic factors in pathogenesis of this syndrome (Frye et all.1964 cited by Warkany 1971. Previous investigations (Checiu et all. 1966 revealed a caudal malformative syndrome in chick embryos induced by Cu2+. It is well known capacity of some heavy metal ions to affect the formation and desintegration reaction of free radicals. The aim of this paper is to present a morphological study of caudal malformative syndrome (Checiu et all. 1999 and an

  10. Chemogenetic activation of the lateral hypothalamus reverses early life stress-induced deficits in motivational drive.

    Science.gov (United States)

    Campbell, Erin J; Mitchell, Caitlin S; Adams, Cameron D; Yeoh, Jiann Wei; Hodgson, Deborah M; Graham, Brett A; Dayas, Christopher V

    2017-10-01

    Altered motivated behaviour is a cardinal feature of several neuropsychiatric conditions including mood disorders. One well-characterized antecedent to the development of mood disorders is exposure to early life stress (ELS). A key brain substrate controlling motivated behaviour is the lateral hypothalamus (LH). Here, we examined the effect of ELS on LH activation and the motivation to self-administer sucrose. We tested whether chemogenetic activation of LH circuits could modify sucrose responding in ELS rats and examined the impact on LH cell populations. Male rat pups were maternally separated for 0 or 3 h on postnatal days 2-14. During adolescence, rats received bilateral injections of hM3D(Gq), the excitatory designer receptor exclusively activated by designer drugs, into LH. In adulthood, rats were trained to self-administer sucrose and tested under a progressive ratio schedule to determine their motivation for reward following injection with either vehicle or 5 mg/kg clozapine-N-oxide. Brains were processed for Fos-protein immunohistochemistry. ELS significantly suppressed lever responding for sucrose, indicating a long-lasting impact of ELS on motivation circuits. hM3D(Gq) activation of LH increased responding, normalizing deficits in ELS rats, and increased Fos-positive orexin and MCH cell numbers within LH. Our findings indicate that despite being susceptible to environmental stressors, LH circuits retain the capacity to overcome ELS-induced deficits in motivated behaviour. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Effect of Hypoxia-Inducible Factor 1α on Early Healing in Extraction Sockets

    Directory of Open Access Journals (Sweden)

    Hyun-Chang Lim

    2018-01-01

    Full Text Available The aim of the present study was to investigate the effect of hypoxia-inducible factor 1α (HIF1A on the early healing (4 weeks of extraction sockets exhibiting partial loss of the labial bone. Two extraction sockets of the maxillary incisors from each of six dogs were assigned to two treatment modalities: deproteinized bovine bone mineral (i with 10% collagen (DBBM-C soaked with HIF1A and covered by a collagen membrane (CM (HIF group or (ii treated with DBBM-C only and covered by a CM (control group. Microcomputed tomography revealed some degree of collapse of the labial contour. The totally augmented volume and new bone volume did not differ significantly between two groups (P>0.05. The histological analysis revealed that the apical area of the socket was mostly filled with newly formed bone, while there was less newly formed bone in the coronal area and incomplete cortex formation. The histomorphometric analysis revealed that the area of newly formed bone was significantly larger in the HIF group than the control group (12.16±3.04 versus 9.48±2.01 mm2, P<0.05, while there was no significant intergroup difference in the total augmented area. In conclusion, even though DBBM-C soaked with HIF1A enhanced histomorphometric bone formation, this intervention did not demonstrate superiority in preventing ridge shrinkage compared to DBBM-C alone. Clinical relevance of these findings should be further studied.

  12. Effect of age on radiation-induced early changes of rat rectum. A histological time sequence

    International Nuclear Information System (INIS)

    Olofsen-van Acht, Manouk J.J.; Hooije, Christel M.C. van; Aardweg, Gerard J.M.J. van den; Levendag, Peter C.; Velthuysen, Marie Louise F. van

    2001-01-01

    Background and purpose: Radiation treatment of the elderly (>75 years) is often modified due to an assumed decrease in normal tissue tolerance in this age group. Since more radiobiological data concerning normal tissue toxicity as a function of age are needed, a histological study of age-related radiation changes of the rectum was performed. Materials and methods: The rectum of young and old female Wistar rats (12 and 78 weeks, respectively) was irradiated with single doses of 22 and 39 Gy. The field size was 1.5x2.0 cm. The animals were sacrificed at 1, 2, 4 and 10 weeks after treatment. To evaluate radiation damage, 12 histological parameters were scored in four areas of the rectum. A total radiation injury score was calculated. The number of proliferative epithelial cells was evaluated by 5-bromo-2'-deoxyuridine labeling. Results: Some age-related histological differences were observed; especially, the incidence of ulceration and vascular occlusion was higher in the older group. In the low dose group of the older animals, 60% showed ulceration, which was 0% for the young low dose animals. Severe vascular changes occurred early and were more extensive in older animals (4 weeks) than in the younger group (10 weeks). In the area adjacent to the treatment field, cell proliferation increased significantly in older rats at 1 week after 22 Gy, which did not occur in the young group. Conclusions: Discrete radiation-induced histological differences were observed between the rectum of young and old Wistar rats, especially in the development of ulceration and vascular changes. Although the survival of these Wistar rats in earlier studies was not affected by age, the impact of the observed histological differences for their importance in the long-term is currently being investigated

  13. Sucrose-induced analgesia during early life modulates adulthood learning and memory formation.

    Science.gov (United States)

    Nuseir, Khawla Q; Alzoubi, Karem H; Alabwaini, Jehad; Khabour, Omar F; Kassab, Manal I

    2015-06-01

    This study is aimed at examining the long-term effects of chronic pain during early life (postnatal day 0 to 8weeks), and intervention using sucrose, on cognitive functions during adulthood in rats. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution or paracetamol was administered for analgesia before the paw prick. Control groups include tactile stimulation to account for handling and touching the paws, and sucrose alone was used. All treatments were started on day one of birth and continued for 8weeks. At the end of the treatments, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM), as well as pain threshold via foot-withdrawal response to a hot plate apparatus. Additionally, the hippocampus was dissected, and blood was collected. Levels of neurotrophins (BDNF, IGF-1 and NT-3) and endorphins were assessed using ELISA. The results show that chronic noxious stimulation resulted in comparable foot-withdrawal latency between noxious and tactile groups. On the other hand, pretreatment with sucrose or paracetamol increased pain threshold significantly both in naive rats and noxiously stimulated rats (Pmemory, and sucrose treatment prevented such impairment (Pmemory impairment, and pretreatment with sucrose prevented this impairment via mechanisms that seem to involve BDNF. As evident in the results, sucrose, whether alone or in the presence of pre-noxious stimulation, increases pain threshold in such circumstances; most likely via a mechanism that involves an increase in endogenous opioids. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The induced expression of heat shock proteins as a part of the early cellular response to gamma radiation

    International Nuclear Information System (INIS)

    Stankova, K.; Ivanova, K.; Georgieva, R.; Rupova, I.; Boteva, R.

    2008-01-01

    A variety of stressful stimuli including gamma radiation can induce increase in the synthesis of heat shock proteins (Hsp). This family of molecular chaperones includes members with molecular masses ranging from 10 to 150 kDa and has been identified in all organisms from bacteria to humans. Hsp70 chaperones are very important. The present study aimed to characterize the radiation-induced changes in Hsp70 synthesis in human lymphocytes as a part of the early cellular response to gamma irradiation. The expression of Hsp70 was determined with Western blot and the radiation-induced apoptotic changes were registered by staining with fluorescent dyes. Part of the experiments were performed in the presence of the organic solvent DMSO. At low concentrations this reagent shows antioxidant activity and can reduce the level of the radiation-induced oxidant stress which determines the predominant biological effects of the ionizing radiation. Irradiation with 0.5 to 8 Gy caused statistically significant increase in the synthesis of Hsp70 which was strongest after irradiation with 4 Gy. In the range 0.5-2 Gy the enhancement of the radiation-induced synthesis of Hsp70 reached 60%. Our experimental results characterize changes in the Hsp70 synthesis after gamma irradiation as a part of the early cellular stress response in lymphocytes. (authors)

  15. Early application of tail nerve electrical stimulation-induced walking training promotes locomotor recovery in rats with spinal cord injury.

    Science.gov (United States)

    Zhang, S-X; Huang, F; Gates, M; Shen, X; Holmberg, E G

    2016-11-01

    This is a randomized controlled prospective trial with two parallel groups. The objective of this study was to determine whether early application of tail nerve electrical stimulation (TANES)-induced walking training can improve the locomotor function. This study was conducted in SCS Research Center in Colorado, USA. A contusion injury to spinal cord T10 was produced using the New York University impactor device with a 25 -mm height setting in female, adult Long-Evans rats. Injured rats were randomly divided into two groups (n=12 per group). One group was subjected to TANES-induced walking training 2 weeks post injury, and the other group, as control, received no TANES-induced walking training. Restorations of behavior and conduction were assessed using the Basso, Beattie and Bresnahan open-field rating scale, horizontal ladder rung walking test and electrophysiological test (Hoffmann reflex). Early application of TANES-induced walking training significantly improved the recovery of locomotor function and benefited the restoration of Hoffmann reflex. TANES-induced walking training is a useful method to promote locomotor recovery in rats with spinal cord injury.

  16. Spectrum and quantum symmetries of the AdS{sub 5} x S{sup 5} superstring

    Energy Technology Data Exchange (ETDEWEB)

    Heinze, Martin

    2014-12-18

    The initial AdS/CFT duality pair, the duality between N=4 SYM and the AdS{sub 5} x S{sup 5} superstring, appears to enjoy quantum integrability in the planar limit, which allowed to devise powerful methods ostensibly solving the spectral problem. However, quantization of the AdS{sub 5} x S{sup 5} superstring from first principles is still an open question and especially the spectrum of short string states has previously been derived only at leading order in large 't Hooft coupling. In this thesis we investigate possible routes to quantize short string states perturbatively beyond the leading order, where equally our aim is to gain better appreciation of the quantum symmetries at play. A prominent role is played by the lowest excited string states, dual to the Konishi supermultiplet, and we start by reviewing critically an asserted derivation of the Konishi anomalous dimension in the setup of pure spinor string theory. Next, we constrain ourselves to bosonic AdS{sub 5} x S{sup 5} String in static gauge, where we construct a so-called single-mode string solution, a generalization of the pulsating string allowing for unconstrained zero-modes. This solution shows classical integrability and invariance under the isometries SO(2,4) x SO(6) at the quantum level. Arguing heuristically about the effects of supersymmetry, we indeed recover the first non-trivial quantum correction to the Konishi anomalous dimension. We continue by implementing static gauge for the full AdS{sub 5} x S{sup 5} superstring and find elegant expressions for the Lagrangian density and the supercharges. We then constrain our interest to the superparticle and, using two different methods, find canonical coordinates at quadratic order in fermions. We conclude by exploring another quantization scheme: As the single-mode string is nothing but the SO(2,4) x SO(6) orbit of the pulsating string, we apply orbit method quantization to the particle and spinning string solutions in bosonic AdS{sub 3} x S

  17. Deciphering early events involved in hyperosmotic stress-induced programmed cell death in tobacco BY-2 cells.

    Science.gov (United States)

    Monetti, Emanuela; Kadono, Takashi; Tran, Daniel; Azzarello, Elisa; Arbelet-Bonnin, Delphine; Biligui, Bernadette; Briand, Joël; Kawano, Tomonori; Mancuso, Stefano; Bouteau, François

    2014-03-01

    Hyperosmotic stresses represent one of the major constraints that adversely affect plants growth, development, and productivity. In this study, the focus was on early responses to hyperosmotic stress- (NaCl and sorbitol) induced reactive oxygen species (ROS) generation, cytosolic Ca(2+) concentration ([Ca(2+)]cyt) increase, ion fluxes, and mitochondrial potential variations, and on their links in pathways leading to programmed cell death (PCD). By using BY-2 tobacco cells, it was shown that both NaCl- and sorbitol-induced PCD seemed to be dependent on superoxide anion (O2·(-)) generation by NADPH-oxidase. In the case of NaCl, an early influx of sodium through non-selective cation channels participates in the development of PCD through mitochondrial dysfunction and NADPH-oxidase-dependent O2·(-) generation. This supports the hypothesis of different pathways in NaCl- and sorbitol-induced cell death. Surprisingly, other shared early responses, such as [Ca(2+)]cyt increase and singlet oxygen production, do not seem to be involved in PCD.

  18. Proteomic responses reveal the differential effects induced by cadmium in mussels Mytilus galloprovincialis at early life stages.

    Science.gov (United States)

    Xu, Lanlan; Peng, Xiao; Yu, Deliang; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2016-08-01

    Cadmium (Cd) has become an important metal contaminant and posed severe risk on the organisms in the coastal environments of the Bohai Sea. Marine mussel Mytilus galloprovincialis is widely distributed along the Bohai coast and consumed as seafood by local residents. Evidences indicate that the early stages of marine organisms are more sensitive to metal contaminants. In this study, we applied two-dimensional electrophoresis-based proteomics to characterize the biological effects of Cd (50 μg L(-1)) in the early life stages (D-shape larval and juvenile) of mussels. The different proteomic responses demonstrated the differential responsive mechanisms to Cd exposure in these two early life stages of mussels. In details, results indicated that Cd mainly induced immune and oxidative stresses in both D-shape larval and juvenile mussels via different pathways. In addition, the significant up-regulation of triosephosphate isomerase and metallothionein confirmed the enhanced energy demand and mobilized detoxification mechanism in D-shape larval mussels exposed to Cd. In juvenile mussels, Cd exposure also induced clear apoptosis. Overall, this work suggests that Cd is a potential immune toxicant to mussel M. galloprovincialis at early life stages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Calculation of the top quark mass in the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Leontaris, G.K.; Rizos, J.; Tamvakis, K. (Ioannina Univ. (Greece). Dept. of Physics)

    1990-11-08

    We present a complete renormalization group calculation of the top-quark mass in the SU(5)xU(1) superstring model. We solve the coupled renormalization group equations for the gauge and Yukawa couplings in the two-loop approximation and obtain the top-quark mass as a function of two parameters of the model which could be chosen to be ratios of singlet VEVs associated with the surplus (U(1)){sup 4} breaking. We obtain a heavy top-quark with 150 GeV{le}m{sub t}<200 GeV, for most part of the parameter space, while lower values are possible only in a very small extremal region. We also compute the allowed range of unification parameters (M{sub x}, sin{sup 2}{theta}{sub w}, {alpha}{sub 3}(M{sub W})) in the presence of a heavy top-quark. (orig.).

  20. Phenomenological constraints imposed by the hidden sector in the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Leontaris, G.K.; Rizos, J.; Tamvakis, K. (Ioannina Univ. (Greece). Theoretical Physics Div.)

    1990-06-28

    We calculate the trilinear superpotential of the hidden sector of the three generation flipped SU(5)xU(1)xU(1){sup 4}xSO(10)xSU(4) superstring model. We perform a renormalization group analysis of the model taking into account the hidden sector. We find that, in all relevant cases, fractionally charged tetraplets of the hidden SO(6) gauge group are confined at a high scale. Nevertheless, their contribution to the observable U(1) gauge coupling evolution results in a drastic reduction of the available freedom in the values of a{sub 3}(m{sub w}), sin{sup 2}{theta}{sub w} and M{sub x} that allow superunification. (orig.).

  1. D-branes in non-critical superstrings and duality in N = 1 gauge theories with flavor

    International Nuclear Information System (INIS)

    Murthy, S.; Troost, J.

    2006-06-01

    We study D-branes in the superstring background R 3,1 x SL(2, R) k =1/U(1) which are extended in the cigar direction. Some of these branes are new. The branes realize flavor in the four dimensional N = 1 gauge theories on the D-branes localized at the tip of the cigar. We study the analytic properties of the boundary conformal field theories on these branes with respect to their defining parameter and find non- trivial monodromies in this parameter. Through this approach, we gain a better understanding of the brane set-ups in ten dimensions involving wrapped NS5-branes. As one application, using the boundary conformal field theory description of the electric and magnetic D-branes, we can understand electric-magnetic (Seiberg) duality in N = 1 SQCD microscopically in a string theoretic context. (author)

  2. Vacuum correlation functions of superfields, properties of matrices of periods, and holomorphic structure of multiloop amplitudes in superstring theory

    International Nuclear Information System (INIS)

    Danilov, G.S.

    1994-01-01

    It is shown that matrices of periods characterizing complex (1|1) supermanifolds of genus n > 1 depend on a spinor structure. This dependence manifests itself in terms proportional to odd moduli. Properties of matrices of periods exert a strong influence on the holomorphic structure of multiloop amplitudes in superstring theory. The supersymmetric analog of the Belavin-Knizhnik theorem is obtained by taking into account the above dependence on odd moduli. Superconformal versions of the Schottky group are used to study matrices of periods. This is essentially the only parametrization in which matrices of periods can be expressed explicitly in terms of even and odd moduli. Superconformal Schottky groups suitable for describing all spinor structures, including the structures for which superfields have branch points, are constructed. A method for calculating vacuum correlation functions of superfields for the above spinor structures is proposed. 18 refs

  3. Soft behavior of a closed massless state in superstring and universality in the soft behavior of the dilaton

    Energy Technology Data Exchange (ETDEWEB)

    Vecchia, Paolo Di [The Niels Bohr Institute, University of Copenhagen,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark); Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm (Sweden); Marotta, Raffaele [Istituto Nazionale di Fisica Nucleare, Sezione di Napoli,Complesso Universitario di Monte S. Angelo ed. 6, via Cintia, 80126, Napoli (Italy); Mojaza, Matin [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, 14476 Potsdam (Germany)

    2016-12-06

    We consider the tree-level scattering amplitudes in the NS-NS (Neveu-Schwarz) massless sector of closed superstrings in the case where one external state becomes soft. We compute the amplitudes generically for any number of dimensions and any number and kind of the massless closed states through the subsubleading order in the soft expansion. We show that, when the soft state is a graviton or a dilaton, the full result can be expressed as a soft theorem factorizing the amplitude in a soft and a hard part. This behavior is similar to what has previously been observed in field theory and in the bosonic string. Differently from the bosonic string, the supersymmetric soft theorem for the graviton has no string corrections at subsubleading order. The dilaton soft theorem, on the other hand, is found to be universally free of string corrections in any string theory.

  4. Off-shell superspace D=10 super Yang-Mills from covariantly quantized Green-Schwarz superstring

    International Nuclear Information System (INIS)

    Nissimov, E.; Pacheva, S.; Solomon, S.

    1988-05-01

    We construct a gauge invariant superspace action in terms of unconstrained off-shell superfields for the D=10 supersymmetric Yang-Mills (SYM) theory. We use to this effect the point particle limit of the BRST charge of the covariantly quantized harmonic Green-Schwarz superstring and a general covariant action principle for overdetermined systems of nonlinear field equations of motion. One obtains gauge and super Poincare invariant equations of motion equivalent to the Nilsson's constraints for D=10 SYM. In the previous approaches (light-cone-gauge, component-fields) one would have to sacrifice either explicit Lorenz invariance or explicit supersymmetry while in the present approach they are both manifest. (authors)

  5. Soft behavior of a closed massless state in superstring and universality of the soft behavior of the dilaton

    DEFF Research Database (Denmark)

    di Vecchia, Paolo; Marotta, Raffaele; Mojaza, Matin

    2016-01-01

    We consider the tree-level scattering amplitudes in the NS-NS (Neveu-Schwarz) massless sector of closed superstrings in the case where one external state becomes soft. We compute the amplitudes generically for any number of dimensions and any number and kind of the massless closed states through...... the subsubleading order in the soft expansion. We show that, when the soft state is a graviton or a dilaton, the full result can be expressed as a soft theorem factorizing the amplitude in a soft and a hard part. This behavior is similar to what has previously been observed in field theory and in the bosonic string....... Differently from the bosonic string, the supersymmetric soft theorem for the graviton has no string corrections at subsubleading order. The dilaton soft theorem, on the other hand, is found to be universally free of string corrections in any string theory....

  6. Expanding (3+1)-dimensional universe from a lorentzian matrix model for superstring theory in (9+1) dimensions.

    Science.gov (United States)

    Kim, Sang-Woo; Nishimura, Jun; Tsuchiya, Asato

    2012-01-06

    We reconsider the matrix model formulation of type IIB superstring theory in (9+1)-dimensional space-time. Unlike the previous works in which the Wick rotation was used to make the model well defined, we regularize the Lorentzian model by introducing infrared cutoffs in both the spatial and temporal directions. Monte Carlo studies reveal that the two cutoffs can be removed in the large-N limit and that the theory thus obtained has no parameters other than one scale parameter. Moreover, we find that three out of nine spatial directions start to expand at some "critical time," after which the space has SO(3) symmetry instead of SO(9).

  7. Improved Microstrip Antenna with HIS Elements and FSS Superstrate for 2.4 GHz Band Applications

    Directory of Open Access Journals (Sweden)

    Praphat Arnmanee

    2018-01-01

    Full Text Available This research presents a microstrip antenna integrated with the high-impedance surface (HIS elements and the modified frequency selective surface (FSS superstrate for 2.4 GHz band applications. The electromagnetic band gap (EBG structure was utilized in the fabrication of both the HIS and FSS structures. An FR-4 substrate with 120 mm × 120 mm × 0.8 mm in dimension (W × L × T and a dielectric constant of 4.3 was used in the antenna design. In the antenna development, the HIS elemental structure was mounted onto the antenna substrate around the radiation patch to suppress the surface wave, and the modified FSS superstrate was suspended 20 mm above the radiating patch to improve the directivity. Simulations were carried out to determine the optimal dimensions of the components and the antenna prototype subsequently fabricated and tested. The simulation and measured results were agreeable. The experimental results revealed that the proposed integrated antenna (i.e., the microstrip antenna with the HIS and FSS structures outperformed the conventional microstrip antenna with regard to reflection coefficient, the radiation pattern, gain, and radiation efficiency. Specifically, the proposed antenna could achieve the measured antenna gain of 10.14 dBi at 2.45 GHz and the reflection coefficient of less than −10 dB and was operable in the 2.39–2.51 GHz frequency range.

  8. Specific synbiotics in early life protect against diet-induced obesity in adult mice

    NARCIS (Netherlands)

    Mischke, Mona; Arora, Tulika; Tims, Sebastian; Engels, Eefje; Sommer, Nina; Limpt, van Kees; Baars, Annemarie; Oozeer, Raish; Oosting, Annemarie; Bäckhed, Fredrik; Knol, Jan

    2018-01-01

    Aims: The metabolic state of human adults is associated with their gut microbiome. The symbiosis between host and microbiome is initiated at birth, and early life microbiome perturbation can disturb health throughout life. Here, we determined how beneficial microbiome interventions in early life

  9. Specific synbiotics in early life protect against diet-induced obesity in adult mice

    DEFF Research Database (Denmark)

    Mischke, Mona; Arora, Tulika; Tims, Sebastian

    2018-01-01

    AIMS: The metabolic state of human adults is associated with their gut microbiome. The symbiosis between host and microbiome is initiated at birth, and early life microbiome perturbation can disturb health long-lastingly. Here, we determined how beneficial microbiome interventions in early life a...... as preventive measure to ameliorate obesity risk and improve metabolic health throughout life....

  10. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    International Nuclear Information System (INIS)

    Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

    2007-01-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  11. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

    2007-02-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  12. Dynamically observing the value of the changes of serum sex hormone levels of early pregnancy after drug-induced abortion

    International Nuclear Information System (INIS)

    Zhao Honggang; Dong Hua; Gu Yan; Zhang Zuncheng

    2009-01-01

    Objective: To observe the value of the changes of serum β-human chorionic gonadotropin (β-HCG), estradiol (E), progesterone (P) Levels of early pregnancy after drug-induced abortion dynamically. Methods: Assessing 55 women proved pregnant by urine or blood HCG retrospecticly, who had terminated their pregnancy by mifepristonr and misoprostol. Meanwhile the serum levels of β-HCG, E, P were monitored dynamically. Results: Among the 55 patients, the levels of β-HCG, E and P had significant decreased (t β-HCG =4.845, t E =7.655, t P =11.390, P E =9.089, P P =2.910, P<0.05). Conclusion: Detectint the serum hormone's levels after drug-induced abortion by chemiluminescent immunoassay, we can assess indirectly the value of administration of mifepristone and misoprostol, predict the prolonged vaginal bleeding after drug-induced abortion, and the outcome of the treatment, which determine wether need another curestage. (authors)

  13. Depletion of HPV16 early genes induces autophagy and senescence in a cervical carcinogenesis model, regardless of viral physical state.

    Science.gov (United States)

    Hanning, Jennifer E; Saini, Harpreet K; Murray, Matthew J; Caffarel, Maria M; van Dongen, Stijn; Ward, Dawn; Barker, Emily M; Scarpini, Cinzia G; Groves, Ian J; Stanley, Margaret A; Enright, Anton J; Pett, Mark R; Coleman, Nicholas

    2013-11-01

    In cervical carcinomas, high-risk human papillomavirus (HR-HPV) may be integrated into host chromosomes or remain extra-chromosomal (episomal). We used the W12 cervical keratinocyte model to investigate the effects of HPV16 early gene depletion on in vitro cervical carcinogenesis pathways, particularly effects shared by cells with episomal versus integrated HPV16 DNA. Importantly, we were able to study the specific cellular consequences of viral gene depletion by using short interfering RNAs known not to cause phenotypic or transcriptional off-target effects in keratinocytes. We found that while cervical neoplastic progression in vitro was characterized by dynamic changes in HPV16 transcript levels, viral early gene expression was required for cell survival at all stages of carcinogenesis, regardless of viral physical state, levels of early gene expression or histology in organotypic tissue culture. Moreover, HPV16 early gene depletion induced changes in host gene expression that were common to both episome-containing and integrant-containing cells. In particular, we observed up-regulation of autophagy genes, associated with enrichment of senescence and innate immune-response pathways, including the senescence-associated secretory phenotype (SASP). In keeping with these observations, HPV16 early gene depletion induced autophagy in both episome-containing and integrant-containing W12 cells, as evidenced by the appearance of autophagosomes, punctate expression of the autophagy marker LC3, conversion of LC3B-I to LC3B-II, and reduced levels of the autophagy substrate p62. Consistent with the reported association between autophagy and senescence pathways, HPV16 early gene depletion induced expression of the senescence marker beta-galactosidase and increased secretion of the SASP-related protein IGFBP3. Together, these data indicate that depleting HR-HPV early genes would be of potential therapeutic benefit in all cervical carcinogenesis pathways, regardless of viral

  14. Interferon-inducible protein 10 (IP-10) is associated with viremia of early HIV-1 infection in Korean patients.

    Science.gov (United States)

    Lee, SoYong; Chung, Yoon-Seok; Yoon, Cheol-Hee; Shin, YoungHyun; Kim, SeungHyun; Choi, Byeong-Sun; Kim, Sung Soon

    2015-05-01

    Cytokines/chemokines play key roles in modulating disease progression in human immunodeficiency virus (HIV) infection. Although it is known that early HIV-1 infection is associated with increased production of proinflammatory cytokines, the relationship between cytokine levels and HIV-1 pathogenesis is not clear. The concentrations of 18 cytokines/chemokines in 30 HIV-1 negative and 208 HIV-1 positive plasma samples from Korean patients were measured by the Luminex system. Early HIV-1 infection was classified according to the Fiebig stage (FS) based on the characteristics of the patients infected with HIV-1. Concentrations of interleukin-12 (IL-12), interferon-inducible protein-10 (IP-10), macrophage inflammatory protein-1α (MIP-1α) and regulated upon activation, normal T cells expressed and secreted (RANTES) were increased significantly during the early stage of HIV-1 infection (FS II-IV) compared with the HIV-1-negative group. Of these cytokines, an elevated level of IP-10 was the only factor to be correlated positively with a higher viral load during the early stages of HIV-1 infection (FS II-IV) in Koreans (R = 0.52, P IP-10 may be an indicator for HIV-1 viremia and associated closely with viral replication in patients with early HIV-1 infection. © 2015 Wiley Periodicals, Inc.

  15. Early life exposure to a rodent carcinogen propiconazole fungicide induces oxidative stress and hepatocarcinogenesis in medaka fish

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Tzu-Yi; Hong, Chwan-Yang [Department of Agricultural Chemistry, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan (China); Sasado, Takao [Laboratory of Bioresources, National Institute for Basic Biology, Okazaki (Japan); Kashiwada, Shosaku [Research Center for Life and Environmental Sciences, Department of Life Sciences, the Toyo University, Gunma (Japan); Chen, Pei-Jen, E-mail: chenpj@ntu.edu.tw [Department of Agricultural Chemistry, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan (China)

    2016-01-15

    Highlights: • Propiconazole initiates ROS-induced oxidative stress and damage in medaka fish. • Early life exposure to propiconazole increases incidence of hepatocarcionogensis in p53{sup −/−} medaka. • Oxidative stress and CYP induction involved in p53 regulation are key events in propiconazole-induced hepatotumorigenesis. • Propiconazole-induced toxic response in medaka is compatible with that in rodents. - Abstract: Conazole pollution is an emerging concern to human health and environmental safety because of the broad use of conazole fungicides in agriculture and medicine and their frequent occurrence in aquifers. The agricultural pesticide propiconazole has received much regulatory interest because it is a known rodent carcinogen with evidence of multiple adverse effects in mammals and non-targeted organisms. However, the carcinogenic effect and associated mechanism of propiconazole in fish under microgram-per-liter levels of environmental-relevant exposure remains unclear. To explore whether early life of propiconzaole exposure would induce oxidative stress and latent carcinogenic effects in fish, we continuously exposed larvae of wild type or p53{sup −/−} mutant of medaka fish (Oryzias latipes) to propiconazole (2.5–250 μg/L) for 3, 7, 14 or 28 days and assessed liver histopathology and/or the oxidative stress response and gene expression during exposure and throughout adulthood. Propiconazole dose-dependently induced reactive oxygen species (ROS) level, altered homeostasis of antioxidant superoxide dismutase, catalase and glutathione S-transferase and caused lipid and protein peroxidation during early life exposure in wild type medaka. Such exposure also significantly upregulated gene expression of the cytochrome P450 CYP1A, but marginally suppressed that of tumor suppressor p53 in adults. Furthermore, histopathology revealed that p53{sup −/−} mutant medaka with early life exposure to propiconazole showed increased incidence of

  16. Early life exposure to a rodent carcinogen propiconazole fungicide induces oxidative stress and hepatocarcinogenesis in medaka fish

    International Nuclear Information System (INIS)

    Tu, Tzu-Yi; Hong, Chwan-Yang; Sasado, Takao; Kashiwada, Shosaku; Chen, Pei-Jen

    2016-01-01

    Highlights: • Propiconazole initiates ROS-induced oxidative stress and damage in medaka fish. • Early life exposure to propiconazole increases incidence of hepatocarcionogensis in p53"−"/"− medaka. • Oxidative stress and CYP induction involved in p53 regulation are key events in propiconazole-induced hepatotumorigenesis. • Propiconazole-induced toxic response in medaka is compatible with that in rodents. - Abstract: Conazole pollution is an emerging concern to human health and environmental safety because of the broad use of conazole fungicides in agriculture and medicine and their frequent occurrence in aquifers. The agricultural pesticide propiconazole has received much regulatory interest because it is a known rodent carcinogen with evidence of multiple adverse effects in mammals and non-targeted organisms. However, the carcinogenic effect and associated mechanism of propiconazole in fish under microgram-per-liter levels of environmental-relevant exposure remains unclear. To explore whether early life of propiconzaole exposure would induce oxidative stress and latent carcinogenic effects in fish, we continuously exposed larvae of wild type or p53"−"/"− mutant of medaka fish (Oryzias latipes) to propiconazole (2.5–250 μg/L) for 3, 7, 14 or 28 days and assessed liver histopathology and/or the oxidative stress response and gene expression during exposure and throughout adulthood. Propiconazole dose-dependently induced reactive oxygen species (ROS) level, altered homeostasis of antioxidant superoxide dismutase, catalase and glutathione S-transferase and caused lipid and protein peroxidation during early life exposure in wild type medaka. Such exposure also significantly upregulated gene expression of the cytochrome P450 CYP1A, but marginally suppressed that of tumor suppressor p53 in adults. Furthermore, histopathology revealed that p53"−"/"− mutant medaka with early life exposure to propiconazole showed increased incidence of

  17. A Breast Tissue Protein Expression Profile Contributing to Early Parity-Induced Protection Against Breast Cancer

    Directory of Open Access Journals (Sweden)

    Christina Marie Gutierrez

    2015-11-01

    Full Text Available Background/Aims: Early parity reduces breast cancer risk, whereas, late parity and nulliparity increase breast cancer risk. Despite substantial efforts to understand the protective effects of early parity, the precise molecular circuitry responsible for these changes is not yet fully defined. Methods: Here, we have conducted the first study assessing protein expression profiles in normal breast tissue of healthy early parous, late parous, and nulliparous women. Breast tissue biopsies were obtained from 132 healthy parous and nulliparous volunteers. These samples were subjected to global protein expression profiling and immunohistochemistry. GeneSpring and MetaCore bioinformatics analysis software were used to identify protein expression profiles associated with early parity (low risk versus late/nulliparity (high risk. Results: Early parity reduces expression of key proteins involved in mitogenic signaling pathways in breast tissue through down regulation of EGFR1/3, ESR1, AKT1, ATF, Fos, and SRC. Early parity is also characterized by greater genomic stability and reduced tissue inflammation based on differential expression of aurora kinases, p53, RAD52, BRCA1, MAPKAPK-2, ATF-1, ICAM1, and NF-kappaB compared to late and nulli parity. Conclusions: Early parity reduces basal cell proliferation in breast tissue, which translates to enhanced genomic stability, reduced cellular stress/inflammation, and thus reduced breast cancer risk.

  18. Federal Financial Incentives to Induce Early Experience Producing Unconventional Liquid Fuels

    National Research Council Canada - National Science Library

    Camm, Frank; Bartis, James T; Bushman, Charles J

    2008-01-01

    ... that is likely to ensure that early CTL production experience occurs cost effectively. Such a relationship yields investor and government behavior that, in turn, generates a set of cash flows to and from...

  19. Federal Financial Incentives to Induce Early Experience Producing Unconventional Liquid Fuels

    National Research Council Canada - National Science Library

    Camm, Frank; Bartis, James T; Bushman, Charles J

    2008-01-01

    This technical report explains an analytic way to design and assess packages of financial incentives that the government can use to cost effectively promote early experience with coal-to-liquids (CTL...

  20. The types and genetic analysis of radiation induced early maturity mutants of rice

    International Nuclear Information System (INIS)

    Yang Hefeng; Chen Xiulan; He Zhengtian; Gu Shiliang; Xu Chenwu

    1989-01-01

    Observation and correlation analysis were made for 50 early mutant lines,The early mutant lines fall into late type of early-maturity rice, and early type of mid- maturity rice, some of which are valuable as materials of rice breeding.With shorter growing period, the mutants have less inter-nodes and leaf numbers on main culm, shorter leaf and panicle length, and less filled grains and yield per plant, but have higher Protein content.Among 20 traits observed, 7 were significantly correlated with the length of growing period.The genetic parameter analysis for the mutant lines indicates that the length of growing period, plant height, grain number per panicle, 1000-grain weight have high heritability, Non-filled grain rate, secondary branch, number of panicle, grain number per panicle have larger genetic coefficient of variation and larger gain of selection

  1. Study on the early and late mutants of radiation induced rice

    International Nuclear Information System (INIS)

    Yang Hefeng; Chen Xiulan; He Zhentian; Gu Shiliang; Xu Chenwu

    1990-12-01

    After three years of consecutive experiments for the irradiated M 2 generations of 53 different varieties of rice, the following results have been obtained: (1) The average of early mutant plant rate is 1.4%. The rate in the early-maturing varieties is lower than that in the late-maturing varieties. It is in proportion to the length of growing period of these varieties tested. The shortened days of growing period of early mutants are 3 to 32 days (the average was 9.5 days), and it is increasing as the growing period increases. (2) In the irradiated M 2 generation of same variety, the early mutants and late mutants could be simultaneously happened, but the rate of the late mutants is 2.67%, which is higher than the rate of early mutants (1.39%). The shortened and prolonged days of growing period are 11.5 and 10.5 days respectively. These early and late mutants have some changes, both good and bad, in agronomical traits such as plant height, weight per kilo-grains and grains number per tassel. In some extent these changes are significant

  2. Gene Expression Patterns during the Early Stages of Chemically Induced Larval Metamorphosis and Settlement of the Coral Acropora millepora

    Science.gov (United States)

    Siboni, Nachshon; Abrego, David; Motti, Cherie A.; Tebben, Jan; Harder, Tilmann

    2014-01-01

    The morphogenetic transition of motile coral larvae into sessile primary polyps is triggered and genetically programmed upon exposure to environmental biomaterials, such as crustose coralline algae (CCA) and bacterial biofilms. Although the specific chemical cues that trigger coral larval morphogenesis are poorly understood there is much more information available on the genes that play a role in this early life phase. Putative chemical cues from natural biomaterials yielded defined chemical samples that triggered different morphogenetic outcomes: an extract derived from a CCA-associated Pseudoalteromonas bacterium that induced metamorphosis, characterized by non-attached metamorphosed juveniles; and two fractions of the CCA Hydrolithon onkodes (Heydrich) that induced settlement, characterized by attached metamorphosed juveniles. In an effort to distinguish the genes involved in these two morphogenetic transitions, competent larvae of the coral Acropora millepora were exposed to these predictable cues and the expression profiles of 47 coral genes of interest (GOI) were investigated after only 1 hour of exposure using multiplex RT–qPCR. Thirty-two GOI were differentially expressed, indicating a putative role during the early regulation of morphogenesis. The most striking differences were observed for immunity-related genes, hypothesized to be involved in cell recognition and adhesion, and for fluorescent protein genes. Principal component analysis of gene expression profiles resulted in separation between the different morphogenetic cues and exposure times, and not only identified those genes involved in the early response but also those which influenced downstream biological changes leading to larval metamorphosis or settlement. PMID:24632854

  3. Notes on the Wess-Zumino-Witten-like structure: L{sub ∞} triplet and NS-NS superstring field theory

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Hiroaki [Institute of Physics, the Czech Academy of Sciences,Na Slovance 2, Prague 8 (Czech Republic); Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan)

    2017-05-17

    In the NS-NS sector of superstring field theory, there potentially exist three nilpotent generators of gauge transformations and two constraint equations: it makes the gauge algebra of type II theory somewhat complicated. In this paper, we show that every NS-NS actions have their WZW-like forms, and that a triplet of mutually commutative L{sub ∞} products completely determines the gauge structure of NS-NS superstring field theory via its WZW-like structure. We give detailed analysis about it and present its characteristic properties by focusing on two NS-NS actions proposed by https://www.doi.org/10.1007/JHEP01(2017)022 and https://www.doi.org/10.1007/JHEP08(2014)158.

  4. Studies on some agronomic and quality characteristics of 271 induced early mutants of rice (Oryza sativa L. cv. Nizersail)

    International Nuclear Information System (INIS)

    Rahman, Mostafizur; Miah, A.J.; Mansur, M.A.; Kaul, A.K.

    1980-01-01

    Nizersail, the most popular, recommended rice variety in Bangladesh, was subjected to gamma-irradiation (10 - 25 kR) or ethyl methane sulfonate (EMS) (0.75 - 1.50%) treatments to obtain the mutants with stiff straw and early maturity. In the M 2 generation, 29 gamma-ray- and 8 EMS-induced mutants were selected mainly for short culm length and earliness. Further selections were made in the segregating M 3 and M 4 populations, and finally 400 plants with short culm length were obtained. These 400 selections were grown in M 5 lines, and 271 of these lines were analyzed for several characters. Heading time had singificantly shifted towards earliness in 40 lines. Yield per plant, 1,000-kernel weight, the length/breadth ratio of kernels, alkali spreading index value (indicator of amylose content) and dye-binding capacity (indicator of protein content) were significantly higher than those in the mother variety in 10 - 30% of the lines examined. However, no positive correlation among these characters was observed. Significant negative correlations were observed between heading time and 1,000-kernel weight, and between yield per plant and dye-binding capacity. These results suggest that the early heading plants may produce fewer tillers with bolder seeds, and that high yielding types may not simultaneously show high protein content. (Kaihara, S.)

  5. Chronic early postnatal scream sound stress induces learning deficits and NMDA receptor changes in the hippocampus of adult mice.

    Science.gov (United States)

    Hu, Lili; Han, Bo; Zhao, Xiaoge; Mi, Lihua; Song, Qiang; Wang, Jue; Song, Tusheng; Huang, Chen

    2016-04-13

    Chronic scream sounds during adulthood affect spatial learning and memory, both of which are sexually dimorphic. The long-term effects of chronic early postnatal scream sound stress (SSS) during postnatal days 1-21 (P1-P21) on spatial learning and memory in adult mice as well as whether or not these effects are sexually dimorphic are unknown. Therefore, the present study examines the performance of adult male and female mice in the Morris water maze following exposure to chronic early postnatal SSS. Hippocampal NR2A and NR2B levels as well as NR2A/NR2B subunit ratios were tested using immunohistochemistry. In the Morris water maze, stress males showed greater impairment in spatial learning and memory than background males; by contrast, stress and background females performed equally well. NR2B levels in CA1 and CA3 were upregulated, whereas NR2A/NR2B ratios were downregulated in stressed males, but not in females. These data suggest that chronic early postnatal SSS influences spatial learning and memory ability, levels of hippocampal NR2B, and NR2A/NR2B ratios in adult males. Moreover, chronic early stress-induced alterations exert long-lasting effects and appear to affect performance in a sex-specific manner.

  6. Superparticle and superstring in AdS3 x S3 Ramond--Ramond background in the light-cone gauge

    International Nuclear Information System (INIS)

    Metsaev, R. R.; Tseytlin, A. A.

    2001-01-01

    We discuss superparticle and superstring dynamics in AdS 3 x S 3 supported by R--R 3-form background using light-cone gauge approach. Starting with the superalgebra psu(1,1|2)(circle plus)psu (1,1|2) representing the basic symmetry of this background we find the light-cone superparticle Hamiltonian. We determine the harmonic decomposition of light-cone superfield describing fluctuations of type IIB supergravity fields expanded near AdS 3 x S 3 background and thus the corresponding Kaluza--Klein spectrum. We fix the fermionic and bosonic light-cone gauges in the covariant Green--Schwarz AdS 3 x S 3 superstring action and find the corresponding light-cone string Hamiltonian. We also obtain a realization of the generators of psu(1,1|2)(circle plus)psu (1,1|2) in terms of the superstring 2-d fields in the light-cone gauge

  7. Risk of docetaxel-induced peripheral neuropathy among 1,725 Danish patients with early stage breast cancer

    DEFF Research Database (Denmark)

    Eckhoff, L; Knoop, A S; Jensen, M-B

    2013-01-01

    Docetaxel-induced peripheral neuropathy (PN) can lead to sub-optimal treatment in women with early breast cancer. Here, we compare the frequency of dose reduction as a result of PN in two different adjuvant regimens. From the Danish Breast Cancer Cooperative Group READ trial we included 1...... on patient-reported outcome (secondary outcome of trial) including PN. Associations between PN and risk factors were analyzed by multivariate logistic regression. Overall 597 patients (34 %) reported PN, grades 2-4, during treatment, 194 (11 %) after the first cycle [early onset peripheral neuropathy (EPN......)] and 403 (23 %) after subsequent cycles [later-onset peripheral neuropathy (LPN)]. The odds ratio (OR) of EPN was significantly increased for the D100 regimen (OR 3.10; 95 % CI 2.18-4.42) while this regimen was associated with reduced OR of LPN (OR 0.69; 95 % CI 0.54-0.88). Patients with PN received...

  8. Hypoglycemic action of vitamin K1 protects against early-onset diabetic nephropathy in streptozotocin-induced rats.

    Science.gov (United States)

    Sai Varsha, M K N; Raman, Thiagarajan; Manikandan, R; Dhanasekaran, G

    2015-10-01

    Vitamin K is a potent regulator of vascular dynamics and prevents vascular calcification. Vitamin K is increasingly being recognized for its antioxidant and antiinflammatory properties. Recently we demonstrated that vitamin K1 (5 mg/kg) protects against streptozotocin-induced type 1 diabetes and diabetic cataract. The aim of this study was to determine whether the hypoglycemic action of vitamin K1 could inhibit early-onset diabetic nephropathy in a streptozotocin-induced rat kidney. Male Wistar rats were administered with 35 mg/kg STZ and after 3 days were treated with vitamin K1 (5 mg/kg, twice a week) for 3 months. Blood glucose was monitored once a month. At the end of the study, animals were sacrificed and kidney was dissected out and analysed for free radicals, antioxidants, aldose reductase, membrane ATPases, histopathology evaluation and expression of pro- and anti-inflammatory cytokines. Urea, uric acid, creatinine, albumin and insulin levels were also estimated. Treatment of diabetic rats with vitamin K1 resulted in a decrease in blood glucose and prevented microalbuminuria. Vitamin K1 also reduced oxidative stress and protected renal physiology by modulating Ca(2+) and Na(+)/K(+)-ATPases. Vitamin K1 inhibited renal inflammation by reducing nuclear factor-κB and inducible nitric oxide synthase. Interleukin-10 levels were increased in renal tissues, suggesting the ability of vitamin K1 to trigger antiinflammatory state. The hypoglycemic action of vitamin K1 could have an indirect effect by inhibiting early-onset diabetic nephropathy triggered by high blood glucose. Vitamin K1 could be an important nutrient based interventional strategy for early onset diabetic nephropathy. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Early dengue virus protein synthesis induces extensive rearrangement of the endoplasmic reticulum independent of the UPR and SREBP-2 pathway.

    Directory of Open Access Journals (Sweden)

    José Peña

    Full Text Available The rearrangement of intracellular membranes has been long reported to be a common feature in diseased cells. In this study, we used dengue virus (DENV to study the role of the unfolded protein response (UPR and sterol-regulatory-element-binding-protein-2 (SREBP-2 pathway in the rearrangement and expansion of the endoplasmic reticulum (ER early after infection. Using laser scanning confocal and differential interference contrast microscopy, we demonstrate that rearrangement and expansion of the ER occurs early after DENV-2 infection. Through the use of mouse embryonic fibroblast cells deficient in XBP1 and ATF6, we show that ER rearrangement early after DENV infection is independent of the UPR. We then demonstrate that enlargement of the ER is independent of the SREBP-2 activation and upregulation of 3-hydroxy-3-methylglutaryl-Coenzyme-A reductase, the rate-limiting enzyme in the cholesterol biosynthesis pathway. We further show that this ER rearrangement is not inhibited by the treatment of DENV-infected cells with the cholesterol-inhibiting drug lovastatin. Using the transcription inhibitor actinomycin D and the translation elongation inhibitor cycloheximide, we show that de novo viral protein synthesis but not host transcription is necessary for expansion and rearrangement of the ER. Lastly, we demonstrate that viral infection induces the reabsorption of lipid droplets into the ER. Together, these results demonstrate that modulation of intracellular membrane architecture of the cell early after DENV-2 infection is driven by viral protein expression and does not require the induction of the UPR and SREBP-2 pathways. This work paves the way for further study of virally-induced membrane rearrangements and formation of cubic membranes.

  10. Study of early laser-induced plasma dynamics: Transient electron density gradients via Thomson scattering and Stark Broadening, and the implications on laser-induced breakdown spectroscopy measurements

    International Nuclear Information System (INIS)

    Diwakar, P.K.; Hahn, D.W.

    2008-01-01

    To further develop laser-induced breakdown spectroscopy (LIBS) as an analytical technique, it is necessary to better understand the fundamental processes and mechanisms taking place during the plasma evolution. This paper addresses the very early plasma dynamics (first 100 ns) using direct plasma imaging, light scattering, and transmission measurements from a synchronized 532-nm probe laser pulse. During the first 50 ns following breakdown, significant Thomson scattering was observed while the probe laser interacted with the laser-induced plasma. The Thomson scattering was observed to peak 15-25 ns following plasma initiation and then decay rapidly, thereby revealing the highly transient nature of the free electron density and plasma equilibrium immediately following breakdown. Such an intense free electron density gradient is suggestive of a non-equilibrium, free electron wave generated by the initial breakdown and growth processes. Additional probe beam transmission measurements and electron density measurements via Stark broadening of the 500.1-nm nitrogen ion line corroborate the Thomson scattering observations. In concert, the data support the finding of a highly transient plasma that deviates from local thermodynamic equilibrium (LTE) conditions during the first tens of nanoseconds of plasma lifetime. The implications of this early plasma transient behavior are discussed in the context of plasma-analyte interactions and the role on LIBS measurements

  11. Photodetection of early cancer by laser-induced fluorescence of a tumor-selective dye: apparatus design and realization

    Science.gov (United States)

    Wagnieres, Georges A.; Depeursinge, Christian D.; Monnier, Philippe; Savary, Jean-Francois; Cornaz, Piet F.; Chatelain, Andre; van den Bergh, Hubert

    1990-07-01

    An apparatus is designed and realized to detect "early" cancer at the surface of the hollow organs in the human body by endoscopic means. The tumor is localized by the laser induced fluorescence of a dye (HPD) which concentrates selectively in the neoplastic tissue after intravenous injection. Fluorescence contrast between the tumor and its normal surroundings is enhanced by subtracting the background autofluorescence which occurs in both types of tissue. This is done by means of 2-color digital images manipulation in real-time. Preliminary clinical tests of the apparatus demonstrated the detection of carcinoma in situ in the esophagus.

  12. Cartilage oligomeric matrix protein deficiency promotes early onset and the chronic development of collagen-induced arthritis

    DEFF Research Database (Denmark)

    Geng, Hui; Carlsen, Stefan; Nandakumar, Kutty

    2008-01-01

    ABSTRACT: INTRODUCTION: Cartilage oligomeric matrix protein (COMP) is a homopentameric protein in cartilage. The development of arthritis, like collagen-induced arthritis (CIA), involves cartilage as a target tissue. We have investigated the development of CIA in COMP-deficient mice. METHODS: COMP......-deficient mice in the 129/Sv background were backcrossed for 10 generations against B10.Q mice, which are susceptible to chronic CIA. COMP-deficient and wild-type mice were tested for onset, incidence, and severity of arthritis in both the collagen and collagen antibody-induced arthritis models. Serum anti......-collagen II and anti-COMP antibodies as well as serum COMP levels in arthritic and wild-type mice were measured by enzyme-linked immunosorbent assay. RESULTS: COMP-deficient mice showed a significant early onset and increase in the severity of CIA in the chronic phase, whereas collagen II-antibody titers were...

  13. Ameliorative effect of dietary genistein on diabetes induced hyper-inflammation and oxidative stress during early stage of wound healing in alloxan induced diabetic mice.

    Science.gov (United States)

    Eo, Hyeyoon; Lee, Hea-Ji; Lim, Yunsook

    2016-09-23

    Among the diabetic complications, diabetic foot ulcer due to delayed wound healing is one of the most significant clinical problems. Early inflammatory stage is important for better prognosis during wound healing. Thus, regulation of inflammatory response during early stage of wound healing is main target for complete cutaneous recovery. This study investigated the role of genistein supplementation in inflammation and oxidative stress, which are related to NLRP3 inflammasome, NFκB and Nrf2 activation, during cutaneous wound healing in alloxan-induced diabetic mice. Mice with diabetes with fasting blood glucose (FBG) levels > 250 mg/dl were fed diets with AIN-93G rodent diet containing 0%, 0.025% (LG) or 0.1% (HG) genistein. After 2 weeks of genistein supplementation, excisional wounds were made by biopsy punches (4 mm). Genistein supplementation improved fasting glucose levels and wound closure rate. Moreover, genistein supplementation restored NLRP3 inflammasome (NLRP3, ASC and caspase-1) at the basal level and ameliorated both inflammation (TNFα, iNOS, COX2 and NFκB) and antioxidant defense system (Nrf2, HO-1, GPx, and catalase) during early stage of wound healing in diabetic mice. Taken together, genistein supplementation would be a potential therapeutic nutrient in prevention and treatment of delayed wound healing by modulation of inflammation and oxidative stress during inflammatory stage. Copyright © 2016. Published by Elsevier Inc.

  14. Muscle Tissue Damage Induced by the Venom of Bothrops asper: Identification of Early and Late Pathological Events through Proteomic Analysis.

    Directory of Open Access Journals (Sweden)

    Cristina Herrera

    2016-04-01

    Full Text Available The time-course of the pathological effects induced by the venom of the snake Bothrops asper in muscle tissue was investigated by a combination of histology, proteomic analysis of exudates collected in the vicinity of damaged muscle, and immunodetection of extracellular matrix proteins in exudates. Proteomic assay of exudates has become an excellent new methodological tool to detect key biomarkers of tissue alterations for a more integrative perspective of snake venom-induced pathology. The time-course analysis of the intracellular proteins showed an early presence of cytosolic and mitochondrial proteins in exudates, while cytoskeletal proteins increased later on. This underscores the rapid cytotoxic effect of venom, especially in muscle fibers, due to the action of myotoxic phospholipases A2, followed by the action of proteinases in the cytoskeleton of damaged muscle fibers. Similarly, the early presence of basement membrane (BM and other extracellular matrix (ECM proteins in exudates reflects the rapid microvascular damage and hemorrhage induced by snake venom metalloproteinases. The presence of fragments of type IV collagen and perlecan one hour after envenoming suggests that hydrolysis of these mechanically/structurally-relevant BM components plays a key role in the genesis of hemorrhage. On the other hand, the increment of some ECM proteins in the exudate at later time intervals is likely a consequence of the action of endogenous matrix metalloproteinases (MMPs or of de novo synthesis of ECM proteins during tissue remodeling as part of the inflammatory reaction. Our results offer relevant insights for a more integrative and systematic understanding of the time-course dynamics of muscle tissue damage induced by B. asper venom and possibly other viperid venoms.

  15. Perturbation of bile acid homeostasis is an early pathogenesis event of drug induced liver injury in rats

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Makoto; Miyake, Manami; Sato, Hiroko; Masutomi, Naoya; Tsutsui, Naohisa [Mitsubishi Tanabe Pharma Corporation, Kisarazu, Chiba 292-0818 (Japan); Adam, Klaus-Peter; Alexander, Danny C.; Lawton, Kay A.; Milburn, Michael V.; Ryals, John A.; Wulff, Jacob E. [Metabolon Inc., 617 Davis Drive, Suite 400, Durham, NC 27713 (United States); Guo, Lining, E-mail: lguo@metabolon.com [Metabolon Inc., 617 Davis Drive, Suite 400, Durham, NC 27713 (United States)

    2013-04-01

    Drug-induced liver injury (DILI) is a significant consideration for drug development. Current preclinical DILI assessment relying on histopathology and clinical chemistry has limitations in sensitivity and discordance with human. To gain insights on DILI pathogenesis and identify potential biomarkers for improved DILI detection, we performed untargeted metabolomic analyses on rats treated with thirteen known hepatotoxins causing various types of DILI: necrosis (acetaminophen, bendazac, cyclosporine A, carbon tetrachloride, ethionine), cholestasis (methapyrilene and naphthylisothiocyanate), steatosis (tetracycline and ticlopidine), and idiosyncratic (carbamazepine, chlorzoxasone, flutamide, and nimesulide) at two doses and two time points. Statistical analysis and pathway mapping of the nearly 1900 metabolites profiled in the plasma, urine, and liver revealed diverse time and dose dependent metabolic cascades leading to DILI by the hepatotoxins. The most consistent change induced by the hepatotoxins, detectable even at the early time point/low dose, was the significant elevations of a panel of bile acids in the plasma and urine, suggesting that DILI impaired hepatic bile acid uptake from the circulation. Furthermore, bile acid amidation in the hepatocytes was altered depending on the severity of the hepatotoxin-induced oxidative stress. The alteration of the bile acids was most evident by the necrosis and cholestasis hepatotoxins, with more subtle effects by the steatosis and idiosyncratic hepatotoxins. Taking together, our data suggest that the perturbation of bile acid homeostasis is an early event of DILI. Upon further validation, selected bile acids in the circulation could be potentially used as sensitive and early DILI preclinical biomarkers. - Highlights: ► We used metabolomics to gain insights on drug induced liver injury (DILI) in rats. ► We profiled rats treated with thirteen hepatotoxins at two doses and two time points. ► The toxins decreased the

  16. Short-Term Second Language and Music Training Induces Lasting Functional Brain Changes in Early Childhood

    Science.gov (United States)

    Moreno, Sylvain; Lee, Yunjo; Janus, Monika; Bialystok, Ellen

    2015-01-01

    Immediate and lasting effects of music or second-language training were examined in early childhood using event-related potentials. Event-related potentials were recorded for French vowels and musical notes in a passive oddball paradigm in thirty-six 4- to 6-year-old children who received either French or music training. Following training, both…

  17. Effects of lipopolysaccharide (LPS) induced inflammatory response on early embryo survival in ewes

    Science.gov (United States)

    Early pregnant ewes were used to determine the effects of endogenous (through LPS activation) and exogenous TNF-alpha tumor necrosis factor-alpha (TNF-alpha) on embryonic loss. Thirty-eight Dorset x Texel ewes were synchronized for estrus and bred to fertile rams (d0). On d5/6, ewes were assigned t...

  18. Photo-induced toxicity in early life stage fiddler crab (Uca longisignalis) following exposure to Deepwater Horizon oil.

    Science.gov (United States)

    Damare, Leigh M; Bridges, Kristin N; Alloy, Matthew M; Curran, Thomas E; Soulen, Brianne K; Forth, Heather P; Lay, Claire R; Morris, Jeffrey M; Stoeckel, James A; Roberts, Aaron P

    2018-05-01

    The 2010 explosion of the Deepwater Horizon (DWH) oil rig led to the release of millions of barrels of oil in the Gulf of Mexico. Oil in aquatic ecosystems exerts toxicity through multiple mechanisms, including photo-induced toxicity following co-exposure with UV radiation. The timing and location of the spill coincided with both fiddler crab reproduction and peak yearly UV intensities, putting early life stage fiddler crabs at risk of injury due to photo-induced toxicity. The present study assessed sensitivity of fiddler crab larvae to photo-induced toxicity during co-exposure to a range of environmentally relevant dilutions of high-energy water accommodated fractions of DWH oil, and either dark recovery period (duration: 17-h) in between. Survival was significantly decreased in treatments the presence of >10% UV and relatively low concentrations of oil. Results of the present study indicate fiddler crab larvae are sensitive to photo-induced toxicity in the presence of DWH oil. These results are of concern, as fiddler crabs play an important role as ecosystem engineers, modulating sediment biogeochemical processes via burrowing action. Furthermore, they occupy an important place in the food web in the Gulf of Mexico.

  19. Molecular pathways involved in the early and late damage induced by testis ischemia: evidence for a rational pharmacological modulation.

    Science.gov (United States)

    Altavilla, D; Romeo, C; Squadrito, F; Marini, H; Morgia, G; Antonuccio, P; Minutoli, L

    2012-01-01

    Testicular torsion or torsion of the spermatic cord is a surgical emergency in which misdiagnosis and inappropriate treatment can lead to male infertility. Events occurring during testicular torsion and detorsion are representative of an ischemia-reperfusion injury observed in other organs. The two most important factors determining testicular damage are the degree of twisting and the early onset of a surgical treatment to counter-rotate both testis and spermatic cord for inducing reperfusion. The damage from reperfusion is more severe than that induced by ischemia and several mechanisms are implicated in the development of testicular damage following torsion and detorsion. However, these mechanisms have not yet been fully clarified and, as a consequence, there is still a strong need to identify specific pharmacological treatment to limit the damage triggered by the reperfusion procedures. Ischemia and reperfusion of testis result in elevated production of reactive oxygen species (ROS), activate mitogen activated protein kinases (MAPKs) and PPARβ/δ receptor, induce transcription factors and growth factors including NF-κB and VEGF, trigger apoptotic machinery and induce several inflammatory cytokines, including TNF-α and IL-1β . This pathological cascade is responsible for the testicular atrophy, decreased blood flow and impaired spermatogenesis. Several pharmacological approaches have been characterized as promising therapeutic agents for the management of testicular torsion and may be useful to ameliorate the sequel of this disease.

  20. Radiation Induced Apoptosis of Murine Bone Marrow Cells Is Independent of Early Growth Response 1 (EGR1.

    Directory of Open Access Journals (Sweden)

    Karine Z Oben

    Full Text Available An understanding of how each individual 5q chromosome critical deleted region (CDR gene contributes to malignant transformation would foster the development of much needed targeted therapies for the treatment of therapy related myeloid neoplasms (t-MNs. Early Growth Response 1 (EGR1 is a key transcriptional regulator of myeloid differentiation located within the 5q chromosome CDR that has been shown to regulate HSC (hematopoietic stem cell quiescence as well as the master regulator of apoptosis-p53. Since resistance to apoptosis is a hallmark of malignant transformation, we investigated the role of EGR1 in apoptosis of bone marrow cells; a cell population from which myeloid malignancies arise. We evaluated radiation induced apoptosis of Egr1+/+ and Egr1-/- bone marrow cells in vitro and in vivo. EGR1 is not required for radiation induced apoptosis of murine bone marrow cells. Neither p53 mRNA (messenger RNA nor protein expression is regulated by EGR1 in these cells. Radiation induced apoptosis of bone marrow cells by double strand DNA breaks induced p53 activation. These results suggest EGR1 dependent signaling mechanisms do not contribute to aberrant apoptosis of malignant cells in myeloid malignancies.

  1. Retinoid-induced expression and activity of an immediate early tumor suppressor gene in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Jeffrey W Streb

    2011-04-01

    Full Text Available Retinoids are used clinically to treat a number of hyper-proliferative disorders and have been shown in experimental animals to attenuate vascular occlusive diseases, presumably through nuclear receptors bound to retinoic acid response elements (RARE located in target genes. Here, we show that natural or synthetic retinoids rapidly induce mRNA and protein expression of a specific isoform of A-Kinase Anchoring Protein 12 (AKAP12β in cultured smooth muscle cells (SMC as well as the intact vessel wall. Expression kinetics and actinomycin D studies indicate Akap12β is a retinoid-induced, immediate-early gene. Akap12β promoter analyses reveal a conserved RARE mildly induced with atRA in a region that exhibits hyper-acetylation. Immunofluorescence microscopy and protein kinase A (PKA regulatory subunit overlay assays in SMC suggest a physical association between AKAP12β and PKA following retinoid treatment. Consistent with its designation as a tumor suppressor, inducible expression of AKAP12β attenuates SMC growth in vitro. Further, immunohistochemistry studies establish marked decreases in AKAP12 expression in experimentally-injured vessels of mice as well as atheromatous lesions in humans. Collectively, these results demonstrate a novel role for retinoids in the induction of an AKAP tumor suppressor that blocks vascular SMC growth thus providing new molecular insight into how retiniods may exert their anti-proliferative effects in the injured vessel wall.

  2. Loss of Roquin induces early death and immune deregulation but not autoimmunity

    Science.gov (United States)

    Bertossi, Arianna; Aichinger, Martin; Sansonetti, Paola; Lech, Maciej; Neff, Frauke; Pal, Martin; Wunderlich, F. Thomas; Anders, Hans-Joachim; Klein, Ludger

    2011-01-01

    The substitution of one amino acid in the Roquin protein by the sanroque mutation induces a dramatic autoimmune syndrome in mice. This is believed to occur through ectopic expression of inducible T cell co-stimulator (ICOS) and unrestrained differentiation of follicular T helper cells, which induce spontaneous germinal center reactions to self-antigens. In this study, we demonstrate that tissue-specific ablation of Roquin in T or B cells, in the entire hematopoietic system, or in epithelial cells of transplanted thymi did not cause autoimmunity. Loss of Roquin induced elevated expression of ICOS through T cell–intrinsic and –extrinsic mechanisms, which itself was not sufficient to break self-tolerance. Instead, ablation of Roquin in the hematopoietic system caused defined changes in immune homeostasis, including the expansion of macrophages, eosinophils, and T cell subsets, most dramatically CD8 effector–like T cells, through cell-autonomous and nonautonomous mechanisms. Germline Roquin deficiency led to perinatal lethality, which was partially rescued on the genetic background of an outbred strain. However, not even complete absence of Roquin resulted in overt self-reactivity, suggesting that the sanroque mutation induces autoimmunity through an as yet unknown mechanism. PMID:21844204

  3. Early maternal separation induces preference for sucrose and aspartame associated with increased blood glucose and hyperactivity.

    Science.gov (United States)

    Aya-Ramos, L; Contreras-Vargas, C; Rico, J L; Dueñas, Z

    2017-07-19

    Early life stress and exposure to sweeteners lead to physiological and behavioral alterations in adulthood. Nevertheless, many genetic and environmental factors as well as the neurobiological mechanisms that contribute to the development of these disorders are not fully understood. Similarly, evidence about the long-term metabolic effects of exposure to sweeteners in early life is limited and inconsistent. This study used an animal model of maternal separation during breastfeeding (MS) to analyze the effects of early life stress on consumption of sweeteners, weight gain, blood glucose and locomotion. Rats were housed under a reversed light/dark cycle (lights off at 7:00 h) with ad libitum access to water and food. In the MS protocol, MS pups were separated from the dam for 6 h per day in two periods of 180 minutes (7:00-10:00 and 13:00-16:00 h) during the dark phase of postnatal day (PND) 1 to PND 21. Non-separated (NS) pups served as controls. On PND 22 rats were grouped by sex and treatment. From PND 26 to PND 50 sucrose and aspartame were provided to rats, and sweetener intake, body weight and blood glucose-related measures were scored. On PND 50, both male and female rats were exposed to the open field test to obtain locomotion and anxiety-related measures. Results showed that both early maternal separation and sweetener intake during adolescence resulted in increased blood glucose and hyperactivity in male rats but not in female rats. Data suggest that the combination of early stress and exposure to sucrose and aspartame could be a risk factor for the development of chronic diseases such as diabetes, as well as for behavioral alterations.

  4. Expression of immediate-early genes in the inferior colliculus and auditory cortex in salicylate-induced tinnitus in rat.

    Science.gov (United States)

    Hu, S S; Mei, L; Chen, J Y; Huang, Z W; Wu, H

    2014-03-12

    Tinnitus could be associated with neuronal hyperactivity in the auditory center. As a neuronal activity marker, immediate-early gene (IEG) expression is considered part of a general neuronal response to natural stimuli. Some IEGs, especially the activity-dependent cytoskeletal protein (Arc) and the early growth response gene-1 (Egr-1), appear to be highly correlated with sensory-evoked neuronal activity. We hypothesize, therefore, an increase of Arc and Egr-1 will be observed in a tinnitus model. In our study, we used the gap prepulse inhibition of acoustic startle (GPIAS) paradigm to confirm that salicylate induces tinnitus-like behavior in rats. However, expression of the Arc gene and Egr-1 gene were decreased in the inferior colliculus (IC) and auditory cortex (AC), in contradiction of our hypothesis. Expression of N-methyl d-aspartate receptor subunit 2B (NR2B) was increased and all of these changes returned to normal 14 days after treatment with salicylate ceased. These data revealed long-time administration of salicylate induced tinnitus markedly but reversibly and caused neural plasticity changes in the IC and the AC. Decreased expression of Arc and Egr-1 might be involved with instability of synaptic plasticity in tinnitus.

  5. Expression of immediate-early genes in the inferior colliculus and auditory cortex in salicylate-induced tinnitus in rat

    Directory of Open Access Journals (Sweden)

    S.S. Hu

    2014-03-01

    Full Text Available Tinnitus could be associated with neuronal hyperactivity in the auditory center. As a neuronal activity marker, immediate-early gene (IEG expression is considered part of a general neuronal response to natural stimuli. Some IEGs, especially the activity-dependent cytoskeletal protein (Arc and the early growth response gene-1 (Egr-1, appear to be highly correlated with sensory-evoked neuronal activity. We hypothesize, therefore, an increase of Arc and Egr-1 will be observed in a tinnitus model. In our study, we used the gap prepulse inhibition of acoustic startle (GPIAS paradigm to confirm that salicylate induces tinnitus-like behavior in rats. However, expression of the Arc gene and Egr-1 gene were decreased in the inferior colliculus (IC and auditory cortex (AC, in contradiction of our hypothesis. Expression of N-methyl d-aspartate receptor subunit 2B (NR2B was increased and all of these changes returned to normal 14 days after treatment with salicylate ceased. These data revealed long-time administration of salicylate induced tinnitus markedly but reversibly and caused neural plasticity changes in the IC and the AC. Decreased expression of Arc and Egr-1 might be involved with instability of synaptic plasticity in tinnitus.

  6. Oxytocin is implicated in social memory deficits induced by early sensory deprivation in mice.

    Science.gov (United States)

    Zhang, Jin-Bao; Chen, Ling; Lv, Zhu-Man; Niu, Xue-Yuan; Shao, Can-Can; Zhang, Chan; Pruski, Michal; Huang, Ying; Qi, Cong-Cong; Song, Ning-Ning; Lang, Bing; Ding, Yu-Qiang

    2016-12-13

    Early-life sensory input plays a crucial role in brain development. Although deprivation of orofacial sensory input at perinatal stages disrupts the establishment of the barrel cortex and relevant callosal connections, its long-term effect on adult behavior remains elusive. In this study, we investigated the behavioral phenotypes in adult mice with unilateral transection of the infraorbital nerve (ION) at postnatal day 3 (P3). Although ION-transected mice had normal locomotor activity, motor coordination, olfaction, anxiety-like behaviors, novel object memory, preference for social novelty and sociability, they presented deficits in social memory and spatial memory compared with control mice. In addition, the social memory deficit was associated with reduced oxytocin (OXT) levels in the hypothalamus and could be partially restored by intranasal administration of OXT. Thus, early sensory deprivation does result in behavioral alterations in mice, some of which may be associated with the disruption of oxytocin signaling.

  7. The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures

    International Nuclear Information System (INIS)

    Sant, Gaurav; Lothenbach, Barbara; Juilland, Patrick; Le Saout, Gwenn; Weiss, Jason; Scrivener, Karen

    2011-01-01

    Studies on the early-age shrinkage behavior of cement pastes, mortars, and concretes containing shrinkage reducing admixtures (SRAs) have indicated these mixtures frequently exhibit an expansion shortly after setting. While the magnitude of the expansion has been noted to be a function of the chemistry of the cement and the admixture dosage; the cause of the expansion is not clearly understood. This investigation uses measurements of autogenous deformation, X-ray diffraction, pore solution analysis, thermogravimetry, and scanning electron microscopy to study the early-age properties and describe the mechanism of the expansion in OPC pastes made with and without SRA. The composition of the pore solution indicates that the presence of the SRA increases the portlandite oversaturation level in solution which can result in higher crystallization stresses which could lead to an expansion. This observation is supported by deformation calculations for the systems examined.

  8. Early bilateral radiation-induced optic neuropathy with follow-up MRI

    International Nuclear Information System (INIS)

    McClellan, R.L.; El Gammal, T.; Kline, L.B.

    1995-01-01

    Most documented cases of radiation-induced optic neuropathy are unilateral and occur more than 1 year after radiotherapy to the sellar region. We describe a patient with bilateral radiation optic neuropathy 3 months following the completion of radiotherapy. MRI 13 months after the onset of visual failure showed bilateral optic atrophy with residual gadolinium enhancement. (orig.)

  9. Early bilateral radiation-induced optic neuropathy with follow-up MRI

    Energy Technology Data Exchange (ETDEWEB)

    McClellan, R.L. [Alabama Univ., Birmingham (United States). Dept. of Radiology; El Gammal, T. [Alabama Univ., Birmingham (United States). Dept. of Radiology; Kline, L.B. [Alabama Univ., Birmingham (United States). Dept. of Radiology

    1995-02-01

    Most documented cases of radiation-induced optic neuropathy are unilateral and occur more than 1 year after radiotherapy to the sellar region. We describe a patient with bilateral radiation optic neuropathy 3 months following the completion of radiotherapy. MRI 13 months after the onset of visual failure showed bilateral optic atrophy with residual gadolinium enhancement. (orig.)

  10. A schizophrenia rat model induced by early postnatal phencyclidine treatment and characterized by Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Broberg, Brian V; Madsen, Kristoffer H; Plath, Niels

    2013-01-01

    administration of phencyclidine (PCP) induces schizophrenia-like symptoms in healthy volunteers and exacerbates symptoms in patients with schizophrenia. In this study, pharmacological Magnetic Resonance Imaging (phMRI) was used to evaluate if rats treated with 20mg/kg PCP on postnatal days 7, 9, and 11 (neo...

  11. Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Neal D. Teaster

    2012-02-01

    Full Text Available N-Acylethanolamines (NAEs are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE. In animal systems this reaction is part of the endocannabinoid signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH, which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440 lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA, enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD and inductive long day (LD conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3, were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

  12. Early Effects of Lipopolysaccharide-Induced Inflammation on Foetal Brain Development in Rat

    Directory of Open Access Journals (Sweden)

    Cristina A Ghiani

    2011-10-01

    Full Text Available Studies in humans and animal models link maternal infection and imbalanced levels of inflammatory mediators in the foetal brain to the aetiology of neuropsychiatric disorders. In a number of animal models, it was shown that exposure to viral or bacterial agents during a period that corresponds to the second trimester in human gestation triggers brain and behavioural abnormalities in the offspring. However, little is known about the early cellular and molecular events elicited by inflammation in the foetal brain shortly after maternal infection has occurred. In this study, maternal infection was mimicked by two consecutive intraperitoneal injections of 200 μg of LPS (lipopolysaccharide/kg to timed-pregnant rats at GD15 (gestational day 15 and GD16. Increased thickness of the CP (cortical plate and hippocampus together with abnormal distribution of immature neuronal markers and decreased expression of markers for neural progenitors were observed in the LPS-exposed foetal forebrains at GD18. Such effects were accompanied by decreased levels of reelin and the radial glial marker GLAST (glial glutamate transporter, and elevated levels of pro-inflammatory cytokines in maternal serum and foetal forebrains. Foetal inflammation elicited by maternal injections of LPS has discrete detrimental effects on brain development. The early biochemical and morphological changes described in this work begin to explain the sequelae of early events that underlie the neurobehavioural deficits reported in humans and animals exposed to prenatal insults.

  13. Early pharmacological inhibition of angiotensin-I converting enzyme activity induces obesity in adulthood

    Directory of Open Access Journals (Sweden)

    Kely ede Picoli Souza

    2015-04-01

    Full Text Available We have investigated early programming of body mass in order to understand the multifactorial etiology of obesity. Considering that the renin-angiotensin system is expressed and functional in the white adipose tissue (WAT and modulates its development, we reasoned whether early transitory inhibition of angiotensin-I converting enzyme activity after birth could modify late body mass development. Therefore, newborn Wistar rats were treated with enalapril (10 mg/kg of body mass or saline, starting at the first day of life until the age of 16 days. Between days 90th and 180th, a group of these animals received high fat diet (HFD. Molecular, biochemical, histological and physiological data were collected. Enalapril treated animals presented hyperphagia, overweight and increased serum level of triglycerides, total cholesterol and leptin, in adult life. Body composition analyses revealed higher fat mass with increased adipocyte size in these animals. Molecular analyses revealed that enalapril treatment increases neuropeptide Y (NPY and cocaine- and amphetamine-regulated transcript (CART gene expression in hypothalamus, fatty acid synthase (FAS and hormone-sensitive lipase (HSL gene expression in retroperitoneal WAT and decreases peroxixome proliferators-activated receptor (PPAR γ, PPARα, uncoupling protein (UCP 2 and UCP3 gene expression in WAT. The results of the current study indicate that enalapril administration during early postnatal development increases body mass, adiposity and serum lipids in adulthood associated with enhanced food intake and decreased metabolic activity in WAT, predisposing to obesity in adulthood.

  14. FGF-2 induces behavioral recovery after early adolescent injury to the motor cortex of rats.

    Science.gov (United States)

    Nemati, Farshad; Kolb, Bryan

    2011-11-20

    Motor cortex injuries in adulthood lead to poor performance in behavioral tasks sensitive to limb movements in the rat. We have shown previously that motor cortex injury on day 10 or day 55 allow significant spontaneous recovery but not injury in early adolescence (postnatal day 35 "P35"). Previous studies have indicated that injection of basic fibroblast growth factor (FGF-2) enhances behavioral recovery after neonatal cortical injury but such effect has not been studied following motor cortex lesions in early adolescence. The present study undertook to investigate the possibility of such behavioral recovery. Rats with unilateral motor cortex lesions were assigned to two groups in which they received FGF-2 or bovine serum albumin (BSA) and were tested in a number of behavioral tests (postural asymmetry, skilled reaching, sunflower seed manipulation, forepaw inhibition in swimming). Golgi-Cox analysis was used to examine the dendritic structure of pyramidal cells in the animals' parietal (layer III) and forelimb (layer V) area of the cortex. The results indicated that rats injected with FGF-2 (but not BSA) showed significant behavioral recovery that was associated with increased dendritic length and spine density. The present study suggests a role for FGF-2 in the recovery of function following injury during early adolescence. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Application of Laser Induced Breakdown Spectroscopy in Early Detection of Red Palm Weevil: (Rhynchophorus ferrugineus) Infestation in Date Palm

    International Nuclear Information System (INIS)

    Farooq, W. A.; Tawfik, Walid; Rasool, K. G.; Aldawood, A. S.

    2015-01-01

    The Kingdom of Saudi Arabia is one of the leading date producing countries. Unfortunately, this important fruit crop is under great threat from the red palm weevil (RPW) (Rhynchophorus ferrugineus), which is a highly invasive pest. Several techniques, including visual inspection, acoustic sensors, sniffer dogs, and pheromone traps have been tried to detect the early stages of a RPW infestation; however, each method has suffered certain logistical and implementation issues. We have applied laser induced breakdown spectroscopy (LIBS) for the early detection of RPW infestation. Through the analysis of the observed LIBS spectra of different infested and healthy samples, we have found presence of Ca, Mg, Na, C, K elements and OH, CN molecules. The spectra also reveal that with the population growth of the pest, the intensity of Mg and Ca atomic lines in LIBS spectra increases rapidly. Similar behavior is observed in the molecular lines of LIBS spectra. The obtained results indicate that the LIBS technique can be used for the early detection of RPW infestation without damaging the date palms. (paper)

  16. Application of Laser Induced Breakdown Spectroscopy in Early Detection of Red Palm Weevil: (Rhynchophorus ferrugineus) Infestation in Date Palm

    Science.gov (United States)

    A. Farooq, W.; G. Rasool, K.; Walid, Tawfik; S. Aldawood, A.

    2015-11-01

    The Kingdom of Saudi Arabia is one of the leading date producing countries. Unfortunately, this important fruit crop is under great threat from the red palm weevil (RPW) (Rhynchophorus ferrugineus), which is a highly invasive pest. Several techniques, including visual inspection, acoustic sensors, sniffer dogs, and pheromone traps have been tried to detect the early stages of a RPW infestation; however, each method has suffered certain logistical and implementation issues. We have applied laser induced breakdown spectroscopy (LIBS) for the early detection of RPW infestation. Through the analysis of the observed LIBS spectra of different infested and healthy samples, we have found presence of Ca, Mg, Na, C, K elements and OH, CN molecules. The spectra also reveal that with the population growth of the pest, the intensity of Mg and Ca atomic lines in LIBS spectra increases rapidly. Similar behavior is observed in the molecular lines of LIBS spectra. The obtained results indicate that the LIBS technique can be used for the early detection of RPW infestation without damaging the date palms.

  17. Low-dose penicillin in early life induces long-term changes in murine gut microbiota, brain cytokines and behavior

    Science.gov (United States)

    Leclercq, Sophie; Mian, Firoz M.; Stanisz, Andrew M.; Bindels, Laure B.; Cambier, Emmanuel; Ben-Amram, Hila; Koren, Omry; Forsythe, Paul; Bienenstock, John

    2017-01-01

    There is increasing concern about potential long-term effects of antibiotics on children's health. Epidemiological studies have revealed that early-life antibiotic exposure can increase the risk of developing immune and metabolic diseases, and rodent studies have shown that administration of high doses of antibiotics has long-term effects on brain neurochemistry and behaviour. Here we investigate whether low-dose penicillin in late pregnancy and early postnatal life induces long-term effects in the offspring of mice. We find that penicillin has lasting effects in both sexes on gut microbiota, increases cytokine expression in frontal cortex, modifies blood–brain barrier integrity and alters behaviour. The antibiotic-treated mice exhibit impaired anxiety-like and social behaviours, and display aggression. Concurrent supplementation with Lactobacillus rhamnosus JB-1 prevents some of these alterations. These results warrant further studies on the potential role of early-life antibiotic use in the development of neuropsychiatric disorders, and the possible attenuation of these by beneficial bacteria. PMID:28375200

  18. Early age sealing of buffer-rock gap by artificial wetting to induce bentonite swelling

    International Nuclear Information System (INIS)

    Holt, Erika; Marjavaara, Pieti

    2012-01-01

    Document available in extended abstract form only. The aim of this work is to study the homogeneous and rapid swelling of bentonite in the gap between the buffer blocks and the rock wall of the Olkiluoto disposal facility by artificial wetting. The focus was on the construction period of the deposition hole and buffer, and thus only the very early ages of the first weeks. In practice it is desirable that the bentonite material has a volume increase sufficient enough to prevent rock scaling while lowering the risks of bentonite piping and erosion due to potential water flow. This initial study was done in a small-scale mock-up in laboratory conditions. The small-scale steel mock-up had dimensions of 39 cm in height by 36 cm in diameter and included 12 pressure sensors, two displacement transducers, thermal couples, and pore water pressure measurements. The radial and axial pressure development was typically measured over a two week period to assess the rate and magnitude of sealing. A steel confining lid was used for simulating overpressure, though in some cases a plexiglass lid was used to take video images of the gap sealing. The buffer blocks were produced by isostatic compression of 100 MPa. The material was MX-80 Wyoming bentonite having a water content of approximately 13% and a dry density of 1890 kg/m 3 . The testing samples were dry sawn and core drilled from the large block and machined to their final dimensions. These were typically 30 x 30 cm, either as a solid block or three disks of 10 cm height each. The diameter was sometimes varied to allow for a change of gap width between 25 to 50 mm The study included various scenarios, such as: eccentric aligned blocks with gap sizes of 5 and 45 mm, free upward swelling or confinement, different types of pellet and granular gap filling, addition of water at varying rates, and longer term test duration. The samples were typically disassembled after two weeks. At this ending point, material assessments were done

  19. Characterization of early events involved in human dendritic cell maturation induced by sensitizers: Cross talk between MAPK signalling pathways

    International Nuclear Information System (INIS)

    Trompezinski, Sandra; Migdal, Camille; Tailhardat, Magalie; Le Varlet, Beatrice; Courtellemont, Pascal; Haftek, Marek; Serres, Mireille

    2008-01-01

    Dendritic cells (DCs), efficient-antigen presenting cells play an important role in initiating and regulating immune responses. DC maturation following exposure to nickel or DNCB induced an up-regulation of phenotypic markers and inflammatory cytokine secretion. Early intracellular mechanisms involved in DC maturation required to be precise. To address this purpose, DCs derived from human monocytes were treated with sensitizers (nickel, DNCB or thimerosal) in comparison with an irritant (SDS). Our data confirming the up-regulation of CD86, CD54 and cytokine secretion (IL-8 and TNFα) induced by sensitizers but not by SDS, signalling transduction involved in DC maturation was investigated using these chemicals. Kinase activity measurement was assessed using two new sensitive procedures (Face TM and CBA) requiring few cells. SDS did not induce changes in signalling pathways whereas NiSO 4 , DNCB and thimerosal markedly activated p38 MAPK and JNK, in contrast Erk1/2 phosphorylation was completely inhibited by DNCB or thimerosal and only activated by nickel. A pre-treatment with p38 MAPK inhibitor (SB203580) suppressed Erk1/2 inhibition induced by DNCB or thimerosal demonstrating a direct interaction between p38 MAPK and Erk1/2. A pre-treatment with an antioxidant, N-acetyl-L-cysteine (NAC) markedly reduced Erk1/2 inhibition and p38 MAPK phosphorylation induced by DNCB and thimerosal, suggesting a direct activation of p38 MAPK via an oxidative stress and a regulation of MAPK signalling pathways depending on chemicals. Because of a high sensitivity of kinase activity measurements, these procedures will be suitable for weak or moderate sensitizer screening

  20. Radiation and chemotherapy bystander effects induce early genomic instability events: telomere shortening and bridge formation coupled with mitochondrial dysfunction.

    LENUS (Irish Health Repository)

    Gorman, Sheeona

    2012-02-01

    The bridge breakage fusion cycle is a chromosomal instability mechanism responsible for genomic changes. Radiation bystander effects induce genomic instability; however, the mechanism driving this instability is unknown. We examined if radiation and chemotherapy bystander effects induce early genomic instability events such as telomere shortening and bridge formation using a human colon cancer explant model. We assessed telomere lengths, bridge formations, mitochondrial membrane potential and levels of reactive oxygen species in bystander cells exposed to medium from irradiated and chemotherapy-treated explant tissues. Bystander cells exposed to media from 2Gy, 5Gy, FOLFOX treated tumor and matching normal tissue showed a significant reduction in telomere lengths (all p values <0.018) and an increase in bridge formations (all p values <0.017) compared to bystander cells treated with media from unirradiated tissue (0Gy) at 24h. There was no significant difference between 2Gy and 5Gy treatments, or between effects elicited by tumor versus matched normal tissue. Bystander cells exposed to media from 2Gy irradiated tumor tissue showed significant depolarisation of the mitochondrial membrane potential (p=0.012) and an increase in reactive oxygen species levels. We also used bystander cells overexpressing a mitochondrial antioxidant manganese superoxide dismutase (MnSOD) to examine if this antioxidant could rescue the mitochondrial changes and subsequently influence nuclear instability events. In MnSOD cells, ROS levels were reduced (p=0.02) and mitochondrial membrane potential increased (p=0.04). These events were coupled with a decrease in percentage of cells with anaphase bridges and a decrease in the number of cells undergoing telomere length shortening (p values 0.01 and 0.028 respectively). We demonstrate that radiation and chemotherapy bystander responses induce early genomic instability coupled with defects in mitochondrial function. Restoring mitochondrial

  1. External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

    International Nuclear Information System (INIS)

    Gagnaire, B.; Cavalié, I.; Pereira, S.; Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C.

    2015-01-01

    Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

  2. External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Gagnaire, B., E-mail: beatrice.gagnaire@irsn.fr [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Cavalié, I. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Pereira, S. [Neolys Diagnostics, Lyon 69373 (France); Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France)

    2015-12-15

    Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

  3. Early uneven ear input induces long-lasting differences in left-right motor function.

    Science.gov (United States)

    Antoine, Michelle W; Zhu, Xiaoxia; Dieterich, Marianne; Brandt, Thomas; Vijayakumar, Sarath; McKeehan, Nicholas; Arezzo, Joseph C; Zukin, R Suzanne; Borkholder, David A; Jones, Sherri M; Frisina, Robert D; Hébert, Jean M

    2018-03-01

    How asymmetries in motor behavior become established normally or atypically in mammals remains unclear. An established model for motor asymmetry that is conserved across mammals can be obtained by experimentally inducing asymmetric striatal dopamine activity. However, the factors that can cause motor asymmetries in the absence of experimental manipulations to the brain remain unknown. Here, we show that mice with inner ear dysfunction display a robust left or right rotational preference, and this motor preference reflects an atypical asymmetry in cortico-striatal neurotransmission. By unilaterally targeting striatal activity with an antagonist of extracellular signal-regulated kinase (ERK), a downstream integrator of striatal neurotransmitter signaling, we can reverse or exaggerate rotational preference in these mice. By surgically biasing vestibular failure to one ear, we can dictate the direction of motor preference, illustrating the influence of uneven vestibular failure in establishing the outward asymmetries in motor preference. The inner ear-induced striatal asymmetries identified here intersect with non-ear-induced asymmetries previously linked to lateralized motor behavior across species and suggest that aspects of left-right brain function in mammals can be ontogenetically influenced by inner ear input. Consistent with inner ear input contributing to motor asymmetry, we also show that, in humans with normal ear function, the motor-dominant hemisphere, measured as handedness, is ipsilateral to the ear with weaker vestibular input.

  4. DELLA-induced early transcriptional changes during etiolated development in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Javier Gallego-Bartolomé

    Full Text Available The hormones gibberellins (GAs control a wide variety of processes in plants, including stress and developmental responses. This task largely relies on the activity of the DELLA proteins, nuclear-localized transcriptional regulators that do not seem to have DNA binding capacity. The identification of early target genes of DELLA action is key not only to understand how GAs regulate physiological responses, but also to get clues about the molecular mechanisms by which DELLAs regulate gene expression. Here, we have investigated the global, early transcriptional response triggered by the Arabidopsis DELLA protein GAI during skotomorphogenesis, a developmental program tightly regulated by GAs. Our results show that the induction of GAI activity has an almost immediate effect on gene expression. Although this transcriptional regulation is largely mediated by the PIFs and HY5 transcription factors based on target meta-analysis, additional evidence points to other transcription factors that would be directly involved in DELLA regulation of gene expression. First, we have identified cis elements recognized by Dofs and type-B ARRs among the sequences enriched in the promoters of GAI targets; and second, an enrichment in additional cis elements appeared when this analysis was extended to a dataset of early targets of the DELLA protein RGA: CArG boxes, bound by MADS-box proteins, and the E-box CACATG that links the activity of DELLAs to circadian transcriptional regulation. Finally, Gene Ontology analysis highlights the impact of DELLA regulation upon the homeostasis of the GA, auxin, and ethylene pathways, as well as upon pre-existing transcriptional networks.

  5. Computational chemistry approach for the early detection of drug-induced idiosyncratic liver toxicity.

    Science.gov (United States)

    Cruz-Monteagudo, Maykel; Cordeiro, M Natália D S; Borges, Fernanda

    2008-03-01

    Idiosyncratic drug toxicity (IDT), considered as a toxic host-dependent event, with an apparent lack of dose response relationship, is usually not predictable from early phases of clinical trials, representing a particularly confounding complication in drug development. Albeit a rare event (usually approach proposed in the present study, can play an important role in addressing IDT in early drug discovery. We report for the first time a systematic evaluation of classification models to predict idiosyncratic hepatotoxicity based on linear discriminant analysis (LDA), artificial neural networks (ANN), and machine learning algorithms (OneR) in conjunction with a 3D molecular structure representation and feature selection methods. These modeling techniques (LDA, feature selection to prevent over-fitting and multicollinearity, ANN to capture nonlinear relationships in the data, as well as the simple OneR classifier) were found to produce QSTR models with satisfactory internal cross-validation statistics and predictivity on an external subset of chemicals. More specifically, the models reached values of accuracy/sensitivity/specificity over 84%/78%/90%, respectively in the training series along with predictivity values ranging from ca. 78 to 86% of correctly classified drugs. An LDA-based desirability analysis was carried out in order to select the levels of the predictor variables needed to trigger the more desirable drug, i.e. the drug with lower potential for idiosyncratic hepatotoxicity. Finally, two external test sets were used to evaluate the ability of the models in discriminating toxic from nontoxic structurally and pharmacologically related drugs and the ability of the best model (LDA) in detecting potential idiosyncratic hepatotoxic drugs, respectively. The computational approach proposed here can be considered as a useful tool in early IDT prognosis.

  6. Efficacy and acceptability of a mifepristone-misoprostol combined regimen for early induced abortion among women in Mexico City.

    Science.gov (United States)

    Peña, Melanie; Dzuba, Ilana G; Smith, Patricio Sanhueza; Mendoza, Luis Jorge Arellano; Bousiéguez, Manuel; Martínez, María Laura García; Polanco, Ranulfo Ríos; Villalón, Antonio Eduardo Flores; Winikoff, Beverly

    2014-10-01

    To evaluate the experience of women receiving mifepristone-misoprostol for early induced abortion in public sector facilities in the Federal District of Mexico City. An open-label prospective study was conducted with 1000 pregnant women who sought induced abortion with a pregnancy of up to 63days of gestation, as measured from the date of their last menstrual period. The study was conducted in three public sector healthcare facilities: two secondary level hospitals and one primary care clinic. Women ingested 200mg mifepristone on day 1, followed by 800μg buccal misoprostol 24hours later, and they returned for follow-up on day 8. The primary outcome was complete abortion without recourse to surgical intervention. A total of 971 women received mifepristone-misoprostol and were included in the analysis for efficacy of treatment. The overall efficacy of the combined medical abortion regimen studied was 97.3% (n=945); the success rate did not vary significantly by gestational age (95.9%-100%; P=0.449). Most women (n=922, 95.0%) had a successful induced abortion with only one dose of misoprostol. The combined mifepristone and buccal misoprostol regimen was found to be highly effective and acceptable among Mexican women. www.ClinicalTrials.gov: NCT00386282. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Semantic Wavelet-Induced Frequency-Tagging (SWIFT Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas.

    Directory of Open Access Journals (Sweden)

    Roger Koenig-Robert

    Full Text Available Primate visual systems process natural images in a hierarchical manner: at the early stage, neurons are tuned to local image features, while neurons in high-level areas are tuned to abstract object categories. Standard models of visual processing assume that the transition of tuning from image features to object categories emerges gradually along the visual hierarchy. Direct tests of such models remain difficult due to confounding alteration in low-level image properties when contrasting distinct object categories. When such contrast is performed in a classic functional localizer method, the desired activation in high-level visual areas is typically accompanied with activation in early visual areas. Here we used a novel image-modulation method called SWIFT (semantic wavelet-induced frequency-tagging, a variant of frequency-tagging techniques. Natural images modulated by SWIFT reveal object semantics periodically while keeping low-level properties constant. Using functional magnetic resonance imaging (fMRI, we indeed found that faces and scenes modulated with SWIFT periodically activated the prototypical category-selective areas while they elicited sustained and constant responses in early visual areas. SWIFT and the localizer were selective and specific to a similar extent in activating category-selective areas. Only SWIFT progressively activated the visual pathway from low- to high-level areas, consistent with predictions from standard hierarchical models. We confirmed these results with criterion-free methods, generalizing the validity of our approach and show that it is possible to dissociate neural activation in early and category-selective areas. Our results provide direct evidence for the hierarchical nature of the representation of visual objects along the visual stream and open up future applications of frequency-tagging methods in fMRI.

  8. Upper bounds on Higgs and top quark masses in the flipped SU(5)xU(1) superstring model

    Energy Technology Data Exchange (ETDEWEB)

    Durand, L.; Lopez, J.L.

    1989-02-02

    In this letter, we use a simplified method to calculate high-energy unitarity constraints on grand unified broken supersymmetric models. We apply the method to the ''flipped'' SU(5)xU(1) superstring model, obtain the constraints at a grand unified mass scale M/sub G/=4x10/sup 16/ GeV, and then use the renormalization group equations to evolve the constraints to the low-energy mass scale M/sub W/. We find upper bounds on the low-energy superpotential parameters which in turn imply absolute upper bounds on the top quark mass, m/sub t/< or approx.200 GeV, and on the lightest neutral Higgs boson mass, Msub(H/sub 1//sup 0/)< or approx.155 GeV. We also obtain an upper bound on Msub(H/sub 1//sup 0/) as a function of m/sub t/ which shows that for favored values of the ratio of Higgs vacuum expectation values Msub(H/sub 1//sup 0/)< or approx.125 GeV.

  9. D-branes in a non-critical superstrings and minimal super Yang-Mills in various dimensions

    International Nuclear Information System (INIS)

    Ashok, S.K.; Murthy, S.; Troost, J.

    2005-11-01

    We construct and analyze D-branes in superstring theories in even dimensions less than ten. The backgrounds under study are supersymmetric R d-1,1 x SL(2,R) k /U(1) where the level of the supercoset is tuned such as to provide bona fide string theory backgrounds. We provide exact boundary states for D-branes that are localized at the tip of the cigar SL(2,R)/U(1) supercoset conformal field theory. We analyze the spectra of open strings on these D-branes and show explicitly that they are consistent with supersymmetry in d = 2,4 and 6. The low energy theory on the world-volume of the D-brane in each case is pure Yang-Mills theory with minimal supersymmetry. In the case with four macroscopic flat directions d = 4, we realize an N = 1 super Yang-Mills theory, and we interpret the backreaction for the dilaton as the running of the gauge coupling, and study the relation between R-symmetry breaking in the gauge theory and the backreaction on the Rr axion. (author)

  10. Early spring, severe frost events, and drought induce rapid carbon loss in high elevation meadows.

    Directory of Open Access Journals (Sweden)

    Chelsea Arnold

    Full Text Available By the end of the 20th century, the onset of spring in the Sierra Nevada mountain range of California has been occurring on average three weeks earlier than historic records. Superimposed on this trend is an increase in the presence of highly anomalous "extreme" years, where spring arrives either significantly late or early. The timing of the onset of continuous snowpack coupled to the date at which the snowmelt season is initiated play an important role in the development and sustainability of mountain ecosystems. In this study, we assess the impact of extreme winter precipitation variation on aboveground net primary productivity and soil respiration over three years (2011 to 2013. We found that the duration of snow cover, particularly the timing of the onset of a continuous snowpack and presence of early spring frost events contributed to a dramatic change in ecosystem processes. We found an average 100% increase in soil respiration in 2012 and 2103, compared to 2011, and an average 39% decline in aboveground net primary productivity observed over the same time period. The overall growing season length increased by 57 days in 2012 and 61 days in 2013. These results demonstrate the dependency of these keystone ecosystems on a stable climate and indicate that even small changes in climate can potentially alter their resiliency.

  11. Successful Object Encoding Induces Increased Directed Connectivity in Presymptomatic Early-Onset Alzheimer’s Disease

    Science.gov (United States)

    Ochoa, John Fredy; Alonso, Joan Francesc; Duque, Jon Edinson; Tobón, Carlos Andrés; Mañanas, Miguel Angel; Lopera, Francisco; Hernández, Alher Mauricio

    2016-01-01

    Background: Recent studies report increases in neural activity in brain regions critical to episodic memory at preclinical stages of Alzheimer’s disease (AD). Although electroencephalography (EEG) is widely used in AD studies, given its non-invasiveness and low cost, there is a need to translate the findings in other neuroimaging methods to EEG. Objective: To examine how the previous findings using functional magnetic resonance imaging (fMRI) at preclinical stage in presenilin-1 E280A mutation carriers could be assessed and extended, using EEG and a connectivity approach. Methods: EEG signals were acquired during resting and encoding in 30 normal cognitive young subjects, from an autosomal dominant early-onset AD kindred from Antioquia, Colombia. Regions of the brain previously reported as hyperactive were used for connectivity analysis. Results: Mutation carriers exhibited increasing connectivity at analyzed regions. Among them, the right precuneus exhibited the highest changes in connectivity. Conclusion: Increased connectivity in hyperactive cerebral regions is seen in individuals, genetically-determined to develop AD, at preclinical stage. The use of a connectivity approach and a widely available neuroimaging technique opens the possibility to increase the use of EEG in early detection of preclinical AD. PMID:27792014

  12. Early visual evoked potentials are modulated by eye position in humans induced by whole body rotations

    Directory of Open Access Journals (Sweden)

    Petit Laurent

    2004-09-01

    Full Text Available Abstract Background To reach and grasp an object in space on the basis of its image cast on the retina requires different coordinate transformations that take into account gaze and limb positioning. Eye position in the orbit influences the image's conversion from retinotopic (eye-centered coordinates to an egocentric frame necessary for guiding action. Neuroimaging studies have revealed eye position-dependent activity in extrastriate visual, parietal and frontal areas that is along the visuo-motor pathway. At the earliest vision stage, the role of the primary visual area (V1 in this process remains unclear. We used an experimental design based on pattern-onset visual evoked potentials (VEP recordings to study the effect of eye position on V1 activity in humans. Results We showed that the amplitude of the initial C1 component of VEP, acknowledged to originate in V1, was modulated by the eye position. We also established that putative spontaneous small saccades related to eccentric fixation, as well as retinal disparity cannot explain the effects of changing C1 amplitude of VEP in the present study. Conclusions The present modulation of the early component of VEP suggests an eye position-dependent activity of the human primary visual area. Our findings also evidence that cortical processes combine information about the position of the stimulus on the retinae with information about the location of the eyes in their orbit as early as the stage of primary visual area.

  13. Early Maternal Deprivation Enhances Voluntary Alcohol Intake Induced by Exposure to Stressful Events Later in Life

    Directory of Open Access Journals (Sweden)

    Sara Peñasco

    2015-01-01

    Full Text Available In the present study, we aimed to assess the impact of early life stress, in the form of early maternal deprivation (MD, 24 h on postnatal day, pnd, 9, on voluntary alcohol intake in adolescent male and female Wistar rats. During adolescence, from pnd 28 to pnd 50, voluntary ethanol intake (20%, v/v was investigated using the two-bottle free choice paradigm. To better understand the relationship between stress and alcohol consumption, voluntary alcohol intake was also evaluated following additional stressful events later in life, that is, a week of alcohol cessation and a week of alcohol cessation combined with exposure to restraint stress. Female animals consumed more alcohol than males only after a second episode of alcohol cessation combined with restraint stress. MD did not affect baseline voluntary alcohol intake but increased voluntary alcohol intake after stress exposure, indicating that MD may render animals more vulnerable to the effects of stress on alcohol intake. During adolescence, when animals had free access to alcohol, MD animals showed lower body weight gain but a higher growth rate than control animals. Moreover, the higher growth rate was accompanied by a decrease in food intake, suggesting an altered metabolic regulation in MD animals that may interact with alcohol intake.

  14. EG-VEGF Maintenance Over Early Gestation to Develop a Pregnancy-Induced Hypertensive Animal Model.

    Science.gov (United States)

    Reynaud, Déborah; Sergent, Frédéric; Abi Nahed, Roland; Brouillet, Sophie; Benharouga, Mohamed; Alfaidy, Nadia

    2018-01-01

    During the last decade, multiple animal models have been developed to mimic hallmarks of pregnancy-induced hypertension (PIH) diseases, which include gestational hypertension, preeclampsia (PE), or eclampsia. Converging in vitro, ex vivo, and clinical studies from our group strongly suggested the potential involvement of the new angiogenic factor EG-VEGF (endocrine gland-derived-VEGF) in the development of PIH. Here, we described the protocol that served to demonstrate that maintenance of EG-VEGF production over 11.5 days post coitus (dpc) in the gravid mice caused the development of PIH. The developed model exhibited most hallmarks of preeclampsia.

  15. Early life history and habitat ecology of estuarine fishes: responses to natural and human induced change

    Directory of Open Access Journals (Sweden)

    Kenneth Able

    2015-12-01

    Full Text Available Our understanding of the early life history of fishes and their habitats has proceeded from basic natural history to ecology, but we often need to return to natural history to address deficiencies in conceptual and quantitative models of ecosystems. This understanding is further limited by the complex life history of fishes and the lack of appreciation of shifting baselines in estuaries. These inadequacies are especially evident when we try to address the effects of human influences, e.g. fishing, urbanization, and climate change. Often our baselines are inadequate or inaccurate. Our work has detected these along the coasts of the U.S. in extensive time series of larval fish ingress into estuaries, studies of the effects of urbanization, and responses to catastrophes such as the BP oil spill. Long-term monitoring, especially, continues to provide critical insights

  16. Breeding for earliness, high yield and disease resistance in rice by means of induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    Haq, M S; Ali, S M; Maniruzzaman, A F.M.; Mansur, A; Islam, R [Atomic Energy Centre, Dacca (Pakistan)

    1970-03-01

    Ten varieties of Boro, Aus and Aman rice were treated with 30 kR of gamma rays from the 500-Ci {sup 60}Co source of the Atomic Energy Centre of Dacca. In addition, two rice varieties were treated with EMS and dES. To suppress tillering, the seeds were sown late and at a high seed rate. 300 normal-looking fertile M{sub 1} plants from each variety were harvested at random. The M{sub 2} progenies were sown on a plant-to-row basis to select for high yield, earliness, blast resistance and response to large doses of nitrogen fertilizer. Characters like plant height, number of tillers, fertile tillers, length of panicle and time from sowing to maturity were checked. As the results showed great variability in the mutagen-treated material the chances for successful selection are promising. (author)

  17. Serum phosphate is an early predictor of outcome in severe acetaminophen-induced hepatotoxicity

    DEFF Research Database (Denmark)

    Schmidt, Lars E; Dalhoff, Kim

    2002-01-01

    Hypophosphatemia is frequently observed in acetaminophen-induced hepatotoxicity and may be involved in the pathogenesis of hepatic failure. The aim of the study was to evaluate the prognostic value of serial measurements of serum phosphate in patients with severe acetaminophen poisoning. Prospect......Hypophosphatemia is frequently observed in acetaminophen-induced hepatotoxicity and may be involved in the pathogenesis of hepatic failure. The aim of the study was to evaluate the prognostic value of serial measurements of serum phosphate in patients with severe acetaminophen poisoning...... Hospital (KCH) criteria. Phosphate concentrations were significantly higher in nonsurvivors than in survivors at 48 to 72 hours after overdose (mean 2.65 +/- 1.18 mmol/L vs. 0.68 +/- 0.22 mmol/L, P L vs. 0.59 +/- 0.23 mmol/L, P ...). A threshold phosphate concentration of 1.2 mmol/L at 48 to 96 hours after overdose had sensitivity 89%, specificity 100%, accuracy 98%, positive predictive value 100%, and negative predictive value 98%. The phosphate criteria had higher sensitivity, accuracy, and positive and negative predictive values than...

  18. Single Silver Nanoparticle Instillation Induced Early and Persisting Moderate Cortical Damage in Rat Kidneys

    Directory of Open Access Journals (Sweden)

    Elisa Roda

    2017-10-01

    Full Text Available The potential toxic effects of silver nanoparticles (AgNPs, administered by a single intratracheal instillation (i.t, was assessed in a rat model using commercial physico-chemical characterized nanosilver. Histopathological changes, overall toxic response and oxidative stress (kidney and plasma protein carbonylation, paralleled by ultrastructural observations (TEM, were evaluated to examine renal responses 7 and 28 days after i.t. application of a low AgNP dose (50 µg/rat, compared to an equivalent dose of ionic silver (7 µg AgNO3/rat. The AgNPs caused moderate renal histopathological and ultrastructural alteration, in a region-specific manner, being the cortex the most affected area. Notably, the bulk AgNO3, caused similar adverse effects with a slightly more marked extent, also triggering apoptotic phenomena. Specifically, 7 days after exposure to both AgNPs and AgNO3, dilatation of the intercapillary and peripheral Bowman’s space was observed, together with glomerular shrinkage. At day 28, these effects still persisted after both treatments, accompanied by an additional injury involving the vascular component of the mesangium, with interstitial micro-hemorrhages. Neither AgNPs nor AgNO3 induced oxidative stress effects in kidneys and plasma, at either time point. The AgNP-induced moderate renal effects indicate that, despite their benefits, novel AgNPs employed in consumer products need exhaustive investigation to ensure public health safety.

  19. Lens epithelial cell apoptosis is an early event in the development of UVB-induced cataract.

    Science.gov (United States)

    Li, W C; Spector, A

    1996-01-01

    Epidemiological and experimental studies have revealed that exposure to UV can induce cataractogenesis. To investigate the mechanism of this induction, viability of the lens epithelial cells from UVB-treated rat lenses were examined. Irradiation of the cultured rat lenses with 8 J/s/m2 UVB for 60 min triggers lens epithelial cell apoptosis as determined by terminal deoxyribonucleotide transferase (TdT) labeling and DNA fragmentation assays. The apoptotic lens epithelial cells were initially found in the equatorial region and then quickly appeared in both equatorial and central regions. The percentage of apoptotic cells continuously increased during the postirradiation incubation. After a 5-h post-UVB incubation, more than 50% of the lens epithelial cells were apoptotic. By 24 h, all of the lens epithelial cells in the irradiated lenses were dead through apoptosis. Associated with this apoptotic process is a large upregulation of the proto-oncogene, c-fos. Opacification appears to follow the death of lens epithelial cells occurring first in the equatorial region and then in the central area. This is also true of classical cataract parameters such as non-protein thiol and wet weight, which are significantly modified only after appreciable epithelial cell apoptosis. Together, these results suggest that the rapid apoptotic death of the lens epithelial cells induced by UVB initiates cataract development.

  20. Endoscopic laser-induced steam generator: a new method of treatment for early gastric cancer

    Science.gov (United States)

    Hayashi, Takuya; Arai, Tsunenori; Tajiri, Hisao; Nogami, Yashiroh; Hino, Kunihiko; Kikuchi, Makoto

    1996-05-01

    The minimum invasive endoscopic treatment for early gastric cancer has been popular in Japan. The endoscopic mucosal resection and laser coagulation by Nd:YAG laser irradiation has been the popular treatment method in this field. However, the submucosal cancer has not been successfully treated by these methods. To treat the submucosal cancer endoscopically, we developed a new coagulation therapy using hot steam generated by Nd:YAG laser. The steam of which temperature was over 10 deg. in Celsius was generated by the laser power of 30 W with 5 ml/min. of saline. The steam was emitted to canine gastric wall under laparotomy or endoscopy for 50 s respectively. Follow up endoscopy was performed on 3, 7, 14, 28 days after the treatment. Histological examination was studied on 7, 28 days, and just after the emission. In the acute observation, the submucosal layer was totally coagulated. On the 7th day, ulceration with white coat was seen. The mucosal defect, submucosal coagulation, and marked edema without muscle degeneration were found by the histological study. On the 14th day, the ulcer advanced in the scar stage. On the 28th day, it completely healed into white scar with mucosal regeneration and mucosal muscle thickening. We could obtain reproducible coagulation up to deep submucosal layer with large area in a short operation time. Moreover there were no degeneration of proper muscle. This treatment effectiveness could be easily controlled by the steam temperature and emission duration. We think that this method can be applied to early gastric cancer including the submucosal cancer, in particular poor risk case for operation. Further study should be done to apply this method to clinical therapy.

  1. Early Overfeed-Induced Obesity Leads to Brown Adipose Tissue Hypoactivity in Rats

    Directory of Open Access Journals (Sweden)

    Douglas L. de Almeida

    2013-12-01

    Full Text Available Background/Aims: Brown adipose tissue activation has been considered a potential anti-obesity mechanism because it is able to expend energy through thermogenesis. In contrast, white adipose tissue stores energy, contributing to obesity. We investigated whether the early programming of obesity by overfeeding during lactation changes structure of interscapular brown adipose tissue in adulthood and its effects on thermogenesis. Methods: Birth of litters was considered day 0. On day 2, litter size was adjusted to normal (9 pups and small (3 pups litters. On day 21, the litters were weaned. A temperature transponder was implanted underneath interscapular brown adipose tissue pads of 81-day-old animals; local temperature was measured during light and dark periods between days 87 and 90. The animals were euthanized, and tissue and blood samples were collected for further analysis. The vagus and retroperitoneal sympathetic nerve activity was recorded. Results: Small litter rats presented significant lower interscapular brown adipose tissue temperature during the light (NL 37.6°C vs. SL 37.2°C and dark (NL 38°C vs. SL 37.6°C periods compared to controls. Morphology of small litter brown adipose tissue showed fewer lipid droplets in the tissue center and more and larger in the periphery. The activity of vagus nerve was 19,9% greater in the small litter than in control (pConclusion: Early overfeeding programming of obesity changes the interscapular brown adipose tissue structure in adulthood, leading to local thermogenesis hypoactivity, which may contribute to obesity in adults.

  2. Early overfeed-induced obesity leads to brown adipose tissue hypoactivity in rats.

    Science.gov (United States)

    de Almeida, Douglas L; Fabrício, Gabriel S; Trombini, Amanda B; Pavanello, Audrei; Tófolo, Laize P; da Silva Ribeiro, Tatiane A; de Freitas Mathias, Paulo C; Palma-Rigo, Kesia

    2013-01-01

    Brown adipose tissue activation has been considered a potential anti-obesity mechanism because it is able to expend energy through thermogenesis. In contrast, white adipose tissue stores energy, contributing to obesity. We investigated whether the early programming of obesity by overfeeding during lactation changes structure of interscapular brown adipose tissue in adulthood and its effects on thermogenesis. Birth of litters was considered day 0. On day 2, litter size was adjusted to normal (9 pups) and small (3 pups) litters. On day 21, the litters were weaned. A temperature transponder was implanted underneath interscapular brown adipose tissue pads of 81-day-old animals; local temperature was measured during light and dark periods between days 87 and 90. The animals were euthanized, and tissue and blood samples were collected for further analysis. The vagus and retroperitoneal sympathetic nerve activity was recorded. Small litter rats presented significant lower interscapular brown adipose tissue temperature during the light (NL 37.6°C vs. SL 37.2°C) and dark (NL 38°C vs. SL 37.6°C) periods compared to controls. Morphology of small litter brown adipose tissue showed fewer lipid droplets in the tissue center and more and larger in the periphery. The activity of vagus nerve was 19,9% greater in the small litter than in control (p<0.01), and no difference was observed in the sympathetic nerve activity. In adulthood, the small litter rats were 11,7% heavier than the controls and presented higher glycemia 13,1%, insulinemia 70% and corticosteronemia 92,6%. Early overfeeding programming of obesity changes the interscapular brown adipose tissue structure in adulthood, leading to local thermogenesis hypoactivity, which may contribute to obesity in adults. © 2013 S. Karger AG, Basel.

  3. Enriched dairy fat matrix diet prevents early life lipopolysaccharide-induced spatial memory impairment at adulthood.

    Science.gov (United States)

    Dinel, A L; Rey, C; Baudry, C; Fressange-Mazda, C; Le Ruyet, P; Nadjar, A; Pallet, P; Joffre, C; Layé, S

    2016-10-01

    Polyunsaturated fatty acids (PUFAs) are essential fatty acids, which are critical for brain development and later life cognitive functions. The main brain PUFAs are docosahexaenoic acid (DHA) for the n-3 family and arachidonic acid (ARA) for the n-6 family, which are provided to the post-natal brain by breast milk or infant formula. Recently, the use of dairy lipids (DL) in replacement of vegetable lipids (VL) was revealed to potently promote the accretion of DHA in the developing brain. Brain DHA, in addition to be a key component of brain development, display potent anti-inflammatory activities, which protect the brain from adverse inflammatory events. In this work, we evaluated the protective effect of partial replacement of VL by DL, supplemented or not with DHA and ARA, on post-natal inflammation and its consequence on memory. Mice were fed with diets poor in vegetal n-3 PUFA (Def VL), balanced in vegetal n-3/n-6 PUFA (Bal VL), balanced in dairy lipids (Bal DL) or enriched in DHA and ARA (Supp VL; Supp DL) from the first day of gestation until adulthood. At post-natal day 14 (PND14), pups received a single administration of the endotoxin lipopolysaccharide (LPS) and brain cytokine expression, microglia phenotype and neurogenesis were measured. In a second set of experiments, memory and neurogenesis were measured at adulthood. Overall, our data showed that lipid quality of the diet modulates early life LPS effect on microglia phenotype, brain cytokine expression and neurogenesis at PND14 and memory at adulthood. In particular, Bal DL diet protects from the adverse effect of early life LPS exposure on PND14 neurogenesis and adult spatial memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Semiclassical equivalence of Green–Schwarz and pure–spinor/hybrid formulations of superstrings in AdS5 × S5 and AdS2 × S2 × T6

    International Nuclear Information System (INIS)

    Cagnazzo, Alessandra; Sorokin, Dmitri; Tseytlin, Arkady A; Wulff, Linus

    2013-01-01

    We demonstrate the equivalence between the worldsheet one-loop partition functions computed near classical string solutions in the Green–Schwarz and in the pure–spinor formulations of superstrings in AdS 5 × S 5 . While their bosonic sectors are the same in the conformal gauge, their fermionic sectors superficially appear to be very different (first versus second-derivative kinetic terms, presence versus absence of fermionic gauge symmetry). Still, we show that the quadratic fluctuation spectrum of 16 fermionic modes of the pure–spinor formulation is the same as in the Green–Schwarz superstring and the contribution of the extra ‘massless’ fermionic modes cancels against that of the pure–spinor ghosts. We also provide evidence for a similar semiclassical equivalence between the Green–Schwarz and the hybrid formulations of superstrings in AdS 2 × S 2 × T 6 by studying several particular examples of string solutions. (paper)

  5. Roux-en-Y Gastric Bypass Surgery Induces Early Plasma Metabolomic and Lipidomic Alterations in Humans Associated with Diabetes Remission

    DEFF Research Database (Denmark)

    Arora, Tulika; Velagapudi, Vidya; Pournaras, Dimitri J

    2015-01-01

    -surgery levels. At 4 days after surgery, insulin levels correlated positively with metabolites of branched chain and aromatic amino acid metabolism and negatively with triglycerides with long-chain fatty acids. Of the 14 subjects with diabetes prior to surgery, 7 were in remission 2 years after surgery....... The subjects in remission displayed higher pre-surgery levels of tricarboxylic acid cycle intermediates and triglycerides with long-chain fatty acids compared with subjects not in remission. Thus, metabolic alterations are induced soon after surgery and subjects with diabetes remission differ in the metabolic......Roux-en-Y gastric bypass (RYGB) is an effective method to attain sustained weight loss and diabetes remission. We aimed to elucidate early changes in the plasma metabolome and lipidome after RYGB. Plasma samples from 16 insulin-resistant morbidly obese subjects, of whom 14 had diabetes, were...

  6. Pathological mechanisms of alcohol-induced hepatic portal hypertension in early stage fibrosis rat model.

    Science.gov (United States)

    Li, Jian; Niu, Jian-Zhao; Wang, Ji-Feng; Li, Yu; Tao, Xiao-Hua

    2005-11-07

    To study the role of hepatic sinusoidal capillarization and perisinusoidal fibrosis in rats with alcohol-induced portal hypertension and to discuss the pathological mechanisms of alcohol-induced hepatic portal hypertension. Fifty SD rats were divided into control group (n=20) and model group (n=30). Alcoholic liver fibrosis rat model was induced by intragastric infusion of a mixture containing alcohol, corn oil and pyrazole (1 000:250:3). Fifteen rats in each group were killed at wk 16. The diameter and pressure of portal vein were measured. Plasma hyaluronic acid (HA), type IV collagen (CoIV) and laminin (LN) were determined by radioimmunoassay. Liver tissue was fixed in formalin (10%) and 6-mum thick sections were routinely stained with Mallory and Sirius Red. Liver tissue was treated with rabbit polyclonal antibody against LN and ColIV. Hepatic non-parenchymal cells were isolated, total protein was extracted and separated by SDS-PAGE. MMP-2 and TIMP-1 protein expression was estimated by Western blotting. The diameter (2.207+/-0.096 vs 1.528+/-0.054 mm, Pportal vein were significantly higher in model group than those in the control group. Plasma HA (129.97+/-16.10 vs 73.09+/-2.38 ng/mL, Pmodel group. Abundant collagen deposited around the central vein of lobules, hepatic sinusoids and hepatocytes in model group. ColI and ColIII increased remarkably and perisinusoids were almost surrounded by ColIII. Immunohistochemical staining showed that ColIV protein level (0.130+/-0.007 vs 0.032+/-0.004, Pprotein level (0.152+/-0.005 vs 0.029+/-0.005, Pmodel group. MMP-2 protein expression (2.306+/-1.089 vs 0.612+/-0.081, Pprotein expression (3.015+/-1.364 vs 0.446+/-0.009, Pmodel group and TIMP-1 protein expression was evidently higher than MMP-2 protein expression (2.669+/-0.170 vs 1.695+/-0.008, Pportal hypertension in rats.

  7. Ultraviolet B irradiation induces expansion of intraepithelial tumor cells in a tissue model of early cancer progression.

    Science.gov (United States)

    Mudgil, Adarsh V; Segal, Nadav; Andriani, Frank; Wang, Youai; Fusenig, Norbert E; Garlick, Jonathan A

    2003-07-01

    Ultraviolet B irradiation is thought to enable skin cancer progression as clones of genetically damaged keratinocytes escape apoptosis and expand at the expense of adjacent normal cells. Mechanisms through which potentially malignant cells in human skin undergo clonal expansion, however, are not well understood. The goal of this study was to characterize the role of ultraviolet B irradiation on the intraepithelial expansion of early stage human tumor cells in organotypic skin cultures. To accomplish this, we have studied the effect of ultraviolet B irradiation on organotypic cultures that were fabricated by mixing normal human keratinocytes with beta-galactosidase-marked, intraepithelial tumor cells (HaCaT-ras, clone II-4), which bear mutations in both p53 alleles and harbor an activated H-ras oncogene. We found that when organotypic mixtures were exposed to an ultraviolet B dose of 50 mJ per cm2, intraepithelial tumor cells underwent a significant degree of proliferative expansion compared to nonirradiated cultures. To understand this response, organotypic cultures of nor-mal keratinocytes were exposed to ultraviolet B and showed a dose-dependent increase in numbers of sunburn cells and TUNEL-positive cells although their proliferation was suppressed. In contrast, neither the apoptotic nor the proliferative response of II-4 cells was altered by ultraviolet B in organotypic cultures. The differential response of these cell types suggested that II-4 cells were resistant to ultraviolet-B-induced alterations, which allowed these intraepithelial tumor cells to gain a selective growth and survival advantage relative to neighboring normal cells. These findings demonstrate that ultraviolet B exposure can induce the intraepithelial expansion of apoptosis-resistant, p53-mutant, and ras-activated keratinocytes, suggesting that this agent can act to promote the early stages of epithelial carcinogenesis.

  8. Myxoviruses do not induce non-specific alterations in membrane permeability early on in infection

    International Nuclear Information System (INIS)

    Foster, K.A.; Micklem, K.J.; Bogomolova, N.N.; Boriskin, Y.S.; Pasternak, C.A.

    1983-01-01

    The permeability characteristics of cells infected with myxoviruses have been studied by measuring the concentrative uptake of nutrients, the concentration of intracellular K + , and the maintenance of the Na + gradient across the plasma membrane. Cells either show no change at all (Sendai virus-infected BHK cells and measles virus-infected Vero cells) or they show a decreased ability to concentrate nutrients, while intracellular K + and the Na + gradient remain unchanged (Sendai and influenza virus-infected L-1210 cells, measles virus-infected lymphocytes and mumps virus-infected L-41 cells). In no case, therefore, was a change observed that resembles the non-specific increase in membrane permeability induced by haemolytic paramyxoviruses (35, 42) or the non-specific membrane leakiness postulated to take place in infected cells (8, 9). A preliminary account of some of these findings has been presented (39)

  9. Algal Toxin Azaspiracid-1 Induces Early Neuronal Differentiation and Alters Peripherin Isoform Stoichiometry

    Directory of Open Access Journals (Sweden)

    Linda V. Hjørnevik

    2015-12-01

    Full Text Available Azaspiracid-1 is an algal toxin that accumulates in edible mussels, and ingestion may result in human illness as manifested by vomiting and diarrhoea. When injected into mice, it causes neurotoxicological symptoms and death. Although it is well known that azaspiracid-1 is toxic to most cells and cell lines, little is known about its biological target(s. A rat PC12 cell line, commonly used as a model for the peripheral nervous system, was used to study the neurotoxicological effects of azaspiracid-1. Azaspiracid-1 induced differentiation-related morphological changes followed by a latter cell death. The differentiated phenotype showed peripherin-labelled neurite-like processes simultaneously as a specific isoform of peripherin was down-regulated. The precise mechanism behind this down-regulation remains uncertain. However, this study provides new insights into the neurological effects of azaspiracid-1 and into the biological significance of specific isoforms of peripherin.

  10. Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831).

    Science.gov (United States)

    Paes, Maria do Carmo Faria; Makino, Lilian Cristina; Vasquez, Leonardo Avendaño; Fernandes, João Batista Kochenborger; Valentin, Fernanda Nogueira; Nakaghi, Laura Satiko Okada

    2015-04-01

    Oscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus.

  11. Patients with the worst outcomes after paracetamol (acetaminophen)-induced liver failure have an early monocytopenia.

    Science.gov (United States)

    Moore, J K; MacKinnon, A C; Man, T Y; Manning, J R; Forbes, S J; Simpson, K J

    2017-02-01

    Acute liver failure (ALF) is associated with significant morbidity and mortality. Studies have implicated the immune response, especially monocyte/macrophages as being important in dictating outcome. To investigate changes in the circulating monocytes and other immune cells serially in patients with ALF, relate these with cytokine concentrations, monocyte gene expression and patient outcome. In a prospective case-control study in the Scottish Liver Transplant Unit, Royal Infirmary Edinburgh, 35 consecutive patients admitted with paracetamol-induced liver failure (POD-ALF), 10 patients with non-paracetamol causes of ALF and 16 controls were recruited. The peripheral blood monocyte phenotype was analysed by flow cytometry, circulating cytokines quantified by protein array and monocyte gene expression array performed and related to outcome. On admission, patients with worst outcomes after POD-ALF had a significant monocytopenia, characterised by reduced classical and expanded intermediate monocyte population. This was associated with reduced circulating lymphocytes and natural killer cells, peripheral cytokine patterns suggestive of a 'cytokine storm' and increased concentrations of cytokines associated with monocyte egress from the bone marrow. Gene expression array did not differentiate patient outcome. At day 4, there was no significant difference in monocyte, lymphocyte or natural killer cells between survivors and the patients with adverse outcomes. Severe paracetamol liver failure is associated with profound changes in the peripheral blood compartment, particularly in monocytes, related with worse outcomes. This is not seen in patients with non-paracetamol-induced liver failure. Significant monocytopenia on admission may allow earlier clarification of prognosis, and it highlights a potential target for therapeutic intervention. © 2016 John Wiley & Sons Ltd.

  12. Early Transcriptional Changes Induced by Wnt/β-Catenin Signaling in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Eduardo Pérez-Palma

    2016-01-01

    Full Text Available Wnt/β-catenin signaling modulates brain development and function and its deregulation underlies pathological changes occurring in neurodegenerative and neurodevelopmental disorders. Since one of the main effects of Wnt/β-catenin signaling is the modulation of target genes, in the present work we examined global transcriptional changes induced by short-term Wnt3a treatment (4 h in primary cultures of rat hippocampal neurons. RNAseq experiments allowed the identification of 170 differentially expressed genes, including known Wnt/β-catenin target genes such as Notum, Axin2, and Lef1, as well as novel potential candidates Fam84a, Stk32a, and Itga9. Main biological processes enriched with differentially expressed genes included neural precursor (GO:0061364, p-adjusted = 2.5 × 10−7, forebrain development (GO:0030900, p-adjusted = 7.3 × 10−7, and stem cell differentiation (GO:0048863 p-adjusted = 7.3 × 10−7. Likewise, following activation of the signaling cascade, the expression of a significant number of genes with transcription factor activity (GO:0043565, p-adjusted = 4.1 × 10−6 was induced. We also studied molecular networks enriched upon Wnt3a activation and detected three highly significant expression modules involved in glycerolipid metabolic process (GO:0046486, p-adjusted = 4.5 × 10−19, learning or memory (GO:0007611, p-adjusted = 4.0 × 10−5, and neurotransmitter secretion (GO:0007269, p-adjusted = 5.3 × 10−12. Our results indicate that Wnt/β-catenin mediated transcription controls multiple biological processes related to neuronal structure and activity that are affected in synaptic dysfunction disorders.

  13. Menses resumption after cancer treatment-induced amenorrhea occurs early or not at all.

    Science.gov (United States)

    Jacobson, Melanie H; Mertens, Ann C; Spencer, Jessica B; Manatunga, Amita K; Howards, Penelope P

    2016-03-01

    To identify factors associated with cancer treatment-induced amenorrhea and time to return of menses. Population-based cohort study. Not applicable. Female cancer survivors who were diagnosed with cancer between the ages of 20 and 35 and were at least 2 years postdiagnosis at the time of recruitment (median = 7 years; interquartile range, 5-11). None. Amenorrhea (≥6 months without menses) and resumption of menses. After excluding women with hysterectomies before cancer diagnosis, 1,043 women were eligible for analysis. Amenorrhea occurred in 31.6% of women. Among women treated with chemotherapy (n = 596), older age at diagnosis (30-35 vs. 20-24 years: adjusted odds ratio [aOR] = 2.37; 95% confidence interval [CI], 1.30, 4.30) and nulligravidity (vs. gravid: aOR = 1.50; 95% CI, 1.02, 2.21) were risk factors for amenorrhea. Among amenorrheic women, menses resumed in most (70.0%), and resumption occurred within 2 years of treatment for 90.0% of women. Survivors of breast cancer were more likely to resume menses at times greater than 1 year compared with lymphoma and pelvic-area cancers. Women diagnosed at older ages, those exposed to chemotherapy, and those exposed to any radiation experienced longer times to return of menses. Women who were older at diagnosis were more likely to have irregular cycles when menses returned. Treatment-induced amenorrhea is common in cancer survivors, although most women resume menses within 2 years. However, once resumed, older women are more likely to have irregular cycles. Age at diagnosis and pregnancy history affect the risk of amenorrhea. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Asymmetric distribution of hypoxia-inducible factor α regulates dorsoventral axis establishment in the early sea urchin embryo.

    Science.gov (United States)

    Chang, Wei-Lun; Chang, Yi-Cheng; Lin, Kuan-Ting; Li, Han-Ru; Pai, Chih-Yu; Chen, Jen-Hao; Su, Yi-Hsien

    2017-08-15

    Hypoxia signaling is an ancient pathway by which animals can respond to low oxygen. Malfunction of this pathway disturbs hypoxic acclimation and can result in various diseases, including cancers. The role of hypoxia signaling in early embryogenesis remains unclear. Here, we show that in the blastula of the sea urchin Strongylocentrotus purpuratus , hypoxia-inducible factor α (HIFα), the downstream transcription factor of the hypoxia pathway, is localized and transcriptionally active on the future dorsal side. This asymmetric distribution is attributable to its oxygen-sensing ability. Manipulations of the HIFα level entrained the dorsoventral axis, as the side with the higher level of HIFα tends to develop into the dorsal side. Gene expression analyses revealed that HIFα restricts the expression of nodal to the ventral side and activates several genes encoding transcription factors on the dorsal side. We also observed that intrinsic hypoxic signals in the early embryos formed a gradient, which was disrupted under hypoxic conditions. Our results reveal an unprecedented role of the hypoxia pathway in animal development. © 2017. Published by The Company of Biologists Ltd.

  15. In-vitro analysis of early calcification in aortic valvular interstitial cells using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Davari, Seyyed Ali; Masjedi, Shirin; Ferdous, Zannatul; Mukherjee, Dibyendu

    2018-01-01

    Calcific aortic valve disease (CAVD) is a major cardiovascular disorder caused by osteogenic differentiation of valvular interstitial cells (VICs) within aortic valves. Conventional methods like colorimetric assays and histology fail to detect small calcium depositions during in-vitro VIC cultures. Laser-induced breakdown spectroscopy (LIBS) is a robust analytical tool used for inorganic materials characterizations, but relatively new to biomedical applications. We employ LIBS, for the first time, for quantitative in-vitro detection of calcium depositions in VICs at various osteogenic differentiation stages. VICs isolated from porcine aortic valves were cultured in osteogenic media over various days. Colorimetric calcium assays based on arsenazo dye and Von Kossa staining measured the calcium depositions within VICs. Simultaneously, LIBS signatures for Ca I (422.67 nm) atomic emission lines were collected for estimating calcium depositions in lyophilized VIC samples. Our results indicate excellent linear correlation between the calcium assay and our LIBS measurements. Furthermore, unlike the assay results, the LIBS results could resolve calcium signals from cell samples with as early as 2 days of osteogenic culture. Quantitatively, the LIBS measurements establish the limit of detection for calcium content in VICs to be ∼0.17±0.04 μg which indicates a 5-fold improvement over calcium assay. Picture: Quantitative LIBS enables in-vitro analysis for early stage detection of calcium deposition within aortic valvular interstitial cells (VICs). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Diversification of intrinsic motoneuron electrical properties during normal development and botulinum toxin-induced muscle paralysis in early postnatal mice.

    Science.gov (United States)

    Nakanishi, S T; Whelan, P J

    2010-05-01

    During early postnatal development, between birth and postnatal days 8-11, mice start to achieve weight-bearing locomotion. In association with the progression of weight-bearing locomotion there are presumed developmental changes in the intrinsic electrical properties of spinal -motoneurons. However, these developmental changes in the properties of -motoneuron properties have not been systematically explored in mice. Here, data are presented documenting the developmental changes of selected intrinsic motoneuron electrical properties, including statistically significant changes in action potential half-width, intrinsic excitability and diversity (quantified as coefficient of variation) of rheobase current, afterhyperpolarization half-decay time, and input resistance. In various adult mammalian preparations, the maintenance of intrinsic motoneuron electrical properties is dependent on activity and/or transmission-sensitive motoneuron-muscle interactions. In this study, we show that botulinum toxin-induced muscle paralysis led to statistically significant changes in the normal development of intrinsic motoneuron electrical properties in the postnatal mouse. This suggests that muscle activity during early neonatal life contributes to the development of normal motoneuron electrical properties.

  17. Investigations of hormones during early abortion induced by prostaglandin Fsub(2α) and 15(S)-methyl-PGFsub(2α)

    International Nuclear Information System (INIS)

    Seifert, B.; Liedtke, M.P.; Brockmann, J.; Beissert, M.; Gstoettner, H.; Alexander, H.; Herter, U.

    1978-01-01

    In early pregnancy up the 7th week of pregnancy PGFsub(2α) was infused and 15(S)-methyl-PGFsub(2α) was applied i.m. to induce menstruation in 20 or 19 cases, respectively. In the tested form of application 15(S)-methyl-PGFsub(2α) is effective in 89 per cent of the cases and in 74 per cent complete abortion was achieved. PGFsub(2α) produced bleeding in 80 per cent only and complete abortion in 55 per cent. The differences in these two groups were not statistically significant. The steroid hormones estradiol and progesterone decrease in a successful application of PGs for induction of abortion and reach a value of 75 per cent at the onset of bleeding. The LH concentration in plasma becomes smaller too. In some cases there is a temporary increase in hormones shortly after starting treatment. The results could indicate that the considerable decrease in hormones before the onset of bleeding might be caused by an alteration of the corpus luteum, which is effective during early pregnangy. (author)

  18. Evaluation of early changes induced by diuron in the rat urinary bladder using different processing methods for scanning electron microscopy.

    Science.gov (United States)

    Fava, Rafaela Marono; Ferragut Cardoso, Ana Paula; da Rocha, Mitscheli Sanches; Nascimento E Pontes, Merielen Garcia; de Camargo, João Lauro Viana; de Oliveira, Maria Luiza Cotrim Sartor

    2015-07-03

    Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] is a substituted urea herbicide carcinogenic to the rat urinary bladder at high dietary levels. The suggested non-genotoxic mode of action (MOA) of diuron encompasses cytotoxicity and necrosis followed by regenerative hyperplasia. Prenecrotic swollen cells as observed under scanning electron microscopy (SEM) have been reported as early morphological alterations, putatively related to diuron cytotoxicity. However, these changes were not observed in a previous SEM study conducted in this laboratory. This study evaluated whether these early alterations are actually due to diuron cytotoxicity or artifacts related to different processing methods used for SEM analysis. Male Wistar rats were fed ad libitum with basal diet, 7.1% sodium saccharin (NaS) or 2.500ppm diuron for seven days or 15 weeks. The urinary bladders were processed for histological and labeling indices examinations and for SEM using two different processing methods. The incidence of simple hyperplasia after 15 weeks of exposure to diuron or to NaS was significantly increased. By SEM, the incidences and severity of lesions were significantly increased in the diuron group independently of exposure time. The different SEM processing methods used allowed for visualization of swollen superficial cells after seven days of diuron exposure. Probably the absence these cells in a previous study was due to the use very few animals. Our results support the hypothesis that the swollen cell is an early key event due to diuron-induced cytotoxicity and is the result of a degenerative process involved in the non-genotoxic carcinogenic mode of action of high doses of diuron. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Evaluation of early changes induced by diuron in the rat urinary bladder using different processing methods for scanning electron microscopy

    International Nuclear Information System (INIS)

    Fava, Rafaela Marono; Ferragut Cardoso, Ana Paula; Sanches da Rocha, Mitscheli; Nascimento e Pontes, Merielen Garcia; Viana de Camargo, João Lauro; Cotrim Sartor de Oliveira, Maria Luiza

    2015-01-01

    Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] is a substituted urea herbicide carcinogenic to the rat urinary bladder at high dietary levels. The suggested non-genotoxic mode of action (MOA) of diuron encompasses cytotoxicity and necrosis followed by regenerative hyperplasia. Prenecrotic swollen cells as observed under scanning electron microscopy (SEM) have been reported as early morphological alterations, putatively related to diuron cytotoxicity. However, these changes were not observed in a previous SEM study conducted in this laboratory. This study evaluated whether these early alterations are actually due to diuron cytotoxicity or artifacts related to different processing methods used for SEM analysis. Male Wistar rats were fed ad libitum with basal diet, 7.1% sodium saccharin (NaS) or 2.500 ppm diuron for seven days or 15 weeks. The urinary bladders were processed for histological and labeling indices examinations and for SEM using two different processing methods. The incidence of simple hyperplasia after 15 weeks of exposure to diuron or to NaS was significantly increased. By SEM, the incidences and severity of lesions were significantly increased in the diuron group independently of exposure time. The different SEM processing methods used allowed for visualization of swollen superficial cells after seven days of diuron exposure. Probably the absence these cells in a previous study was due to the use very few animals. Our results support the hypothesis that the swollen cell is an early key event due to diuron-induced cytotoxicity and is the result of a degenerative process involved in the non-genotoxic carcinogenic mode of action of high doses of diuron

  20. DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, Francesco; Wyrobek, Andrew J.

    2009-01-18

    Exposure to ionizing radiation and other environmental agents can affect the genomic integrity of germ cells and induce adverse health effects in the progeny. Efficient DNA repair during gametogenesis and the early embryonic cycles after fertilization is critical for preventing transmission of DNA damage to the progeny and relies on maternal factors stored in the egg before fertilization. The ability of the maternal repair machinery to repair DNA damage in both parental genomes in the fertilizing egg is especially crucial for the fertilizing male genome that has not experienced a DNA repair-competent cellular environment for several weeks prior to fertilization. During the DNA repair-deficient period of spermatogenesis, DNA lesions may accumulate in sperm and be carried into the egg where, if not properly repaired, could result in the formation of heritable chromosomal aberrations or mutations and associated birth defects. Studies with female mice deficient in specific DNA repair genes have shown that: (i) cell cycle checkpoints are activated in the fertilized egg by DNA damage carried by the sperm; and (ii) the maternal genotype plays a major role in determining the efficiency of repairing genomic lesions in the fertilizing sperm and directly affect the risk for abnormal reproductive outcomes. There is also growing evidence that implicates DNA damage carried by the fertilizing gamete as a mediator of postfertilization processes that contribute to genomic instability in subsequent generations. Transgenerational genomic instability most likely involves epigenetic mechanisms or error-prone DNA repair processes in the early embryo. Maternal and embryonic DNA repair processes during the early phases of mammalian embryonic development can have far reaching consequences for the genomic integrity and health of subsequent generations.