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Sample records for jonas vilys vytautas

  1. Ventilator-Induced Lung Injury (VILI) in Acute Respiratory Distress Syndrome (ARDS): Volutrauma and Molecular Effects

    PubMed Central

    Carrasco Loza, R; Villamizar Rodríguez, G; Medel Fernández, N

    2015-01-01

    Acute Respiratory Distress Syndrome (ARDS) is a clinical condition secondary to a variety of insults leading to a severe acute respiratory failure and high mortality in critically ill patients. Patients with ARDS generally require mechanical ventilation, which is another important factor that may increase the ALI (acute lung injury) by a series of pathophysiological mechanisms, whose common element is the initial volutrauma in the alveolar units, and forming part of an entity known clinically as ventilator-induced lung injury (VILI). Injured lungs can be partially protected by optimal settings and ventilation modes, using low tidal volume (VT) values and high positive-end expiratory pressure (PEEP). The benefits in ARDS outcomes caused by these interventions have been confirmed by several prospective randomized controlled trials (RCTs) and are attributed to reduction in volutrauma. The purpose of this article is to present an approach to VILI pathophysiology focused on the effects of volutrauma that lead to lung injury and the ‘mechanotransduction’ mechanism. A more complete understanding about the molecular effects that physical forces could have, is essential for a better assessment of existing strategies as well as the development of new therapeutic strategies to reduce the damage resulting from VILI, and thereby contribute to reducing mortality in ARDS. PMID:26312103

  2. [Hans Jonas: Nature Conservation, Conservation of Life].

    PubMed

    Burgui Burgui, Mario

    2015-01-01

    This article discusses three of the problems that the German philosopher Hans Jonas studied. The first one addresses the need for a specific ethic dedicated to the moral dimension of environmental problems, from a different perspective to the traditional. The second problem is crucial in the discussion on environmental ethics: the value of the nature. Does the nature have an intrinsic value or an instrumental value only (to satisfy the interests of the human being)? The thesis of Jonas, which claimed that nature is a good in itself, were further elaborated here. And the third problem is the derivation of moral norms and the role of man in this ethic that recognizes a good in itself in nature. According to Jonas, the human being is not diminished by recognizing the intrinsic value of nature, since the man's uniqueness and value are unquestionable. From these three central issues, the paper highlights the importance of seeking the links between bioethics and environmental ethics to address the current environmental, social and economic crisis. PMID:26378598

  3. Holographic Nambu-Jona-Lasinio interactions

    NASA Astrophysics Data System (ADS)

    Evans, Nick; Kim, Keun-Young

    2016-03-01

    Nambu-Jona-Lasinio (NJL) interactions are introduced into the D3/probe D7 system using Witten's double trace operator prescription which includes the operator as a classical term in the effective potential. In the supersymmetric system the interactions do not induce chiral symmetry breaking, which we attribute to the flat effective potential with quark mass in the supersymmetric theory. If additional supersymmetry breaking is introduced, then standard NJL behavior is realized. In examples where chiral symmetry breaking is not preferred, such as with a B field plus an IR cutoff, chiral condensation is triggered by the NJL interaction at a second-order transition after a finite critical coupling. If the model already contains chiral symmetry breaking, for example in the B field case with no IR cutoff, then the NJL interaction enhances the quark mass at all values of the NJL coupling. We also consider the system at finite temperature: the temperature discourages condensation, but when combined with a magnetic field, we find regions of parameter space where the NJL interaction triggers a first-order chiral transition above a critical coupling.

  4. Lung stress, strain, and energy load: engineering concepts to understand the mechanism of ventilator-induced lung injury (VILI).

    PubMed

    Nieman, Gary F; Satalin, Joshua; Andrews, Penny; Habashi, Nader M; Gatto, Louis A

    2016-12-01

    It was recently shown that acute respiratory distress syndrome (ARDS) mortality has not been reduced in over 15 years and remains ~40 %, even with protective low tidal volume (LVt) ventilation. Thus, there is a critical need to develop novel ventilation strategies that will protect the lung and reduce ARDS mortality. Protti et al. have begun to analyze the impact of mechanical ventilation on lung tissue using engineering methods in normal pigs ventilated for 54 h. They used these methods to assess the impact of a mechanical breath on dynamic and static global lung strain and energy load. Strain is the change in lung volume in response to an applied stress (i.e., Tidal Volume-Vt). This study has yielded a number of exciting new concepts including the following: (1) Individual mechanical breath parameters (e.g., Vt or Plateau Pressure) are not directly correlated with VILI but rather any combination of parameters that subject the lung to excessive dynamic strain and energy/power load will cause VILI; (2) all strain is not equal; dynamic strain resulting in a dynamic energy load (i.e., kinetic energy) is more damaging to lung tissue than static strain and energy load (i.e., potential energy); and (3) a critical consideration is not just the size of the Vt but the size of the lung that is being ventilated by this Vt. This key concept merits attention since our current protective ventilation strategies are fixated on the priority of keeping the Vt low. If the lung is fully inflated, a large Vt is not necessarily injurious. In conclusion, using engineering concepts to analyze the impact of the mechanical breath on the lung is a novel new approach to investigate VILI mechanisms and to help design the optimally protective breath. Data generated using these methods have challenged some of the current dogma surrounding the mechanisms of VILI and of the components in the mechanical breath necessary for lung protection. PMID:27316442

  5. Nambu-Jona-Lasinio theory and dynamical breaking of supersymmetry

    NASA Astrophysics Data System (ADS)

    Maru, Nobuhito

    2016-06-01

    A recently proposed new mechanism of D-term-triggered dynamical supersymmetry breaking is reviewed. Supersymmetry is dynamically broken by a nonvanishing D-term vacuum expectation value, which is realized as a nontrivial solution of the gap equation in the self-consistent approximation, as in the case of the Nambu-Jona-Lasinio model and BCS superconductivity.

  6. Intersecting branes and Nambu-Jona-Lasinio model

    SciTech Connect

    Dhar, Avinash; Nag, Partha

    2009-06-15

    We discuss chiral symmetry breaking in the intersecting brane model of Sakai and Sugimoto at weak coupling for a generic value of separation L between the flavor D8 and anti-D8-branes. For any finite value of the radius R of the circle around which the color D4-branes wrap, a nonlocal Nambu-Jona-Lasinio-type short-range interaction couples the flavor branes and antibranes. We argue that chiral symmetry is broken in this model only above a certain critical value of the four-dimensional 't Hooft coupling and confirm this through numerical calculations of solutions to the gap equation. We also numerically investigate chiral symmetry breaking in the limit R{yields}{infinity} keeping L fixed, but find that simple ways of implementing this limit do not lead to a consistent picture of chiral symmetry breaking in the noncompact version of the nonlocal Nambu-Jona-Lasinio model.

  7. Dual quark condensate in the Polyakov-loop extended Nambu-Jona-Lasinio model

    SciTech Connect

    Kashiwa, Kouji; Yahiro, Masanobu; Kouno, Hiroaki

    2009-12-01

    The dual quark condensate {sigma}{sup (n)} proposed recently as a new order parameter of the spontaneous breaking of the Z{sub 3} symmetry are evaluated by the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model, where n are winding numbers. The Polyakov-loop extended Nambu-Jona-Lasinio model well reproduces lattice QCD data on {sigma}{sup (1)} measured very lately. The dual quark condensate {sigma}{sup (n)} at higher temperatures is sensitive to the strength of the vector-type four-quark interaction in the Polyakov-loop extended Nambu-Jona-Lasinio model and hence a good quantity to determine the strength.

  8. Natural responsibilities. Philosophy, biology, and ethics in Ernst Mayr and Hans Jonas.

    PubMed

    Donnelley, Strachan

    2002-01-01

    Mayr from biology, Jonas from philosophy, both worked their way--against the philosophical current--toward a biologically informed philosophy that both draws from the natural sciences and reflects a responsibility toward nature. PMID:12362522

  9. Extensions and further applications of the nonlocal Polyakov-Nambu-Jona-Lasinio model

    SciTech Connect

    Hell, T.; Weise, W.; Kashiwa, K.

    2011-06-01

    The nonlocal Polyakov-loop-extended Nambu-Jona-Lasinio model is further improved by including momentum-dependent wave-function renormalization in the quark quasiparticle propagator. Both two- and three-flavor versions of this improved Polyakov-loop-extended Nambu-Jona-Lasinio model are discussed, the latter with inclusion of the (nonlocal) 't Hooft-Kobayashi-Maskawa determinant interaction in order to account for the axial U(1) anomaly. Thermodynamics and phases are investigated and compared with recent lattice-QCD results.

  10. Osteomyelitis and neoplasia associated with use of the Jonas intramedullary splint in small animals.

    PubMed

    Sinibaldi, K R; Pugh, J; Rosen, H; Liu, S K

    1982-11-01

    In 11 cases (10 dogs, 1 cat) in which fractures were repaired with the Jonas intramedullary splint, osteomyelitis developed in 6 and tumors developed in 5. In each case, the tumor originated in close proximity to the splint, at the midshaft of the femur or radius. All implants had been in place for 6 months to 6 years in the case of tumors, and for 4 months to 6 years in the cases involving osteomyelitis. Corrosion was evident in all retrieved implants. The corrosion was attributed to fabrication of the devices with a corrosion-susceptible stainless steel, AISI type 304. The corrosion was believed to have been accelerated by stress effect due to differences in cold work of the sleeve and pin and the difference in composition between the sleeve and spring of the splint. It was concluded that fixation of fractures in small animals should not be performed with the Jonas intramedullary splint. PMID:6958670

  11. Crystalline ground states in Polyakov-loop extended Nambu-Jona-Lasinio models

    NASA Astrophysics Data System (ADS)

    Braun, Jens; Karbstein, Felix; Rechenberger, Stefan; Roscher, Dietrich

    2016-01-01

    Nambu-Jona-Lasinio-type models have been used extensively to study the dynamics of the theory of the strong interaction at finite temperature and quark chemical potential on a phenomenological level. In addition to these studies, which are often performed under the assumption that the ground state of the theory is homogeneous, searches for the existence of crystalline phases associated with inhomogeneous ground states have attracted a lot of interest in recent years. In this work, we study the Polyakov-loop extended Nambu-Jona-Lasinio model using two prominent parametrizations and find that the existence of a crystalline phase is stable against a variation of the parametrization of the underlying Polyakov loop potential.

  12. Inverse magnetic catalysis in Nambu-Jona-Lasinio model beyond mean field

    NASA Astrophysics Data System (ADS)

    Mao, Shijun

    2016-07-01

    We study inverse magnetic catalysis in the Nambu-Jona-Lasinio model beyond mean field approximation. The feed-down from mesons to quarks is embedded in an effective coupling constant at finite temperature and magnetic field. While the magnetic catalysis is still the dominant effect at low temperature, the meson dressed quark mass drops down with increasing magnetic field at high temperature due to the dimension reduction of the Goldstone mode in the Pauli-Villars regularization scheme.

  13. Natural law Judaism? The genesis of bioethics in Hans Jonas, Leo Strauss, and Leon Kass.

    PubMed

    Vogel, Lawrence

    2006-01-01

    Leon Kass is much misunderstood. He is not simply a Republican ideologue who tailored his ideas to break out of the ivory tower and into the halls of power. Nor does he look simply to use human nature as a moral guide. When the full range of his writings is considered and set in the tradition of his teachers, Hans Jonas and Leo Strauss, what emerges is a natural law position colored by religious revelation. PMID:16776021

  14. Nambu-Jona-Lasinio model of qq Bose-Einstein condensation and a pseudogap phase

    SciTech Connect

    Castorina, P.; Zappala, D.; Nardulli, G.

    2005-10-01

    We show the existence of a pseudogap phase in the Nambu-Jona-Lasinio model of quark interactions. In the pseudogap phase chiral symmetry is restored but qq pseudoscalar mesons still exist and they are massive. Such a behavior is intermediate between a BCS superconductor and a Bose-Einstein Condensate. We suggest the relevance of this phenomenon for an understanding of recent lattice QCD and experimental data.

  15. Low-energy processes of meson production in the extended Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Volkov, M. K.; Arbuzov, A. B.

    2016-07-01

    The processes of meson production in electron-positron collisions at low energies are characterized within the extended Nambu-Jona-Lasinio model. It is demonstrated that intermediate vector mesons (both in the ground state and in the first radially excited one) play a critical part in these processes. The obtained results are in reasonable agreement with the available experimental data. A number of theoretical predictions are made, which can be tested experimentally in the near future.

  16. Emergence of a nonuniform pion condensate in the (1 + 1)-dimensional Nambu-Jona-Lasinio model

    SciTech Connect

    Gubina, N. V. Zhukovsky, V. Ch.; Klimenko, K. G.; Kurbanov, S. G.

    2013-11-15

    The (1 + 1)-dimensional Nambu-Jona-Lasinio model describing the system of two-flavor quarks is studied in the limit of a large number of colors in the presence of a baryon chemical potential Micro-Sign and an isospin chemical potential Micro-Sign {sub I}. The possible formation of a nonuniform pion condensate in dense quark matter is considered for the cases of both the massive and the massless model.

  17. The literature of medical ethics: A review of the writings of Hans Jonas

    PubMed Central

    Cooper, F B K

    1976-01-01

    Hans Jonas, who was trained in Germany in the 1920s as a philosopher, had written studies of gnosticism while still living in Germany and some of his work in that field was published after he had left the country. After the Second World War Jonas settled in the United States of America where he is now the Alvin Johnson Professor of Philosophy at the New School for Social Research in New York City. For some years Hans Jonas has directed his research to philosophical studies of medical ethics, in particular to the problems created by recent advances in medical technology. His first book on this theme, `The Phenomenon of Life: Towards a Philosophical Biology', provides the philosophical background to his latest studies and was published in 1966. The essays included in that volume date from 1950 onwards. His second, `Philosophical Essays: From Ancient Creed to Technological Man', continues his analysis and argument from 1964 to the present day but is more particularly concerned with the practical problems of medical ethics encountered by clinicians and research workers, for example, experiments on comatose patients. Dr Cooper in this review outlines in some detail the theses of these volumes. PMID:784996

  18. Renal hypoperfusion and impaired endothelium-dependent vasodilation in an animal model of VILI: the role of the peroxynitrite-PARP pathway

    PubMed Central

    2010-01-01

    Introduction Mechanical ventilation (MV) can injure the lungs and contribute to an overwhelming inflammatory response, leading to acute renal failure (ARF). We previously showed that poly(adenosine diphosphate-ribose) polymerase (PARP) is involved in the development of ventilator-induced lung injury (VILI) and the related ARF, but the mechanisms underneath remain unclear. In the current study we therefore tested the hypothesis that renal blood flow and endothelial, functional and tissue changes in the kidney of rats with lipopolysaccharide (LPS)-induced lung injury aggravated by MV, is caused, in part, by activation of PARP by peroxynitrite. Methods Anesthetized Sprague Dawley rats (n = 31), were subjected to intratracheal instillation of lipopolysaccharide at 10 mg/kg followed by 210 min of mechanical ventilation at either low tidal volume (6 mL/kg) with 5 cm H2O positive end-expiratory pressure or high tidal volume (19 mL/kg) with zero positive end-expiratory pressure in the presence or absence of a peroxynitrite decomposition catalyst, WW85 or a PARP inhibitor, PJ-34. During the experiment, hemodynamics and blood gas variables were monitored. At time (t) t = 0 and t = 180 min, renal blood flow was measured. Blood and urine were collected for creatinine clearance measurement. Arcuate renal arteries were isolated for vasoreactivity experiment and kidneys snap frozen for staining. Results High tidal volume ventilation resulted in lung injury, hypotension, renal hypoperfusion and impaired renal endothelium-dependent vasodilation, associated with renal dysfunction and tissue changes (leukocyte accumulation and increased expression of neutrophil gelatinase-associated lipocalin). Both WW85 and PJ-34 treatments attenuated lung injury, preserved blood pressure, attenuated renal endothelial dysfunction and maintained renal blood flow. In multivariable analysis, renal blood flow improvement was, independently from each other, associated with both maintained blood pressure

  19. Correlation between conserved charges in Polyakov-Nambu-Jona-Lasinio model with multiquark interactions

    SciTech Connect

    Bhattacharyya, Abhijit; Deb, Paramita; Lahiri, Anirban; Ray, Rajarshi

    2011-01-01

    We present a study of correlations among conserved charges like baryon number, electric charge and strangeness in the framework of 2+1 flavor Polyakov loop extended Nambu-Jona-Lasinio model at vanishing chemical potentials, up to fourth order. Correlations up to second order have been measured in lattice QCD, which compares well with our estimates given the inherent difference in the pion masses in the two systems. Possible physical implications of these correlations and their importance in understanding the matter obtained in heavy-ion collisions are discussed. We also present a comparison of the results with the commonly used unbound effective potential in the quark sector of this model.

  20. Polyakov loop extended Nambu Jona-Lasinio model with imaginary chemical potential

    NASA Astrophysics Data System (ADS)

    Sakai, Yuji; Kashiwa, Kouji; Kouno, Hiroaki; Yahiro, Masanobu

    2008-03-01

    The Polyakov loop extended Nambu Jona-Lasinio (PNJL) model with imaginary chemical potential is studied. The model possesses the extended Z3 symmetry that QCD does. Quantities invariant under the extended Z3 symmetry, such as the partition function, the chiral condensate, and the modified Polyakov loop, have Roberge-Weiss periodicity. The phase diagram of confinement/deconfinement transition derived with the PNJL model is consistent with the Roberge-Weiss prediction on it and the results of lattice QCD. The phase diagram of chiral transition is also presented by the PNJL model.

  1. Compact stars with a quark core within the Nambu-Jona-Lasinio (NJL) model

    SciTech Connect

    Lenzi, C. H.; Schneider, A. S.; Providencia, C.; Marinho, R. M. Jr.

    2010-07-15

    An ultraviolet cutoff dependent on the chemical potential as proposed by Casalbuoni et al. is used in the SU(3) Nambu-Jona-Lasinio model. The model is applied to the description of stellar quark matter and compact stars. It is shown that with a new cutoff parametrization it is possible to obtain stable hybrid stars with a quark core. A larger cutoff at finite densities leads to a partial chiral symmetry restoration of quark s at lower densities. A direct consequence is the onset of the s quark in stellar matter at lower densities and a softening of the equation of state.

  2. Parameter fitting in three-flavor Nambu-Jona-Lasinio model with various regularizations

    NASA Astrophysics Data System (ADS)

    Kohyama, H.; Kimura, D.; Inagaki, T.

    2016-05-01

    We study the three-flavor Nambu-Jona-Lasinio model with various regularization procedures. We perform parameter fitting in each regularization and apply the obtained parameter sets to evaluate various physical quantities, several light meson masses, decay constant and the topological susceptibility. The model parameters are adopted even at very high cutoff scale compare to the hadronic scale to study the asymptotic behavior of the model. It is found that all the regularization methods except for the dimensional one actually lead reliable physical predictions for the kaon decay constant, sigma meson mass and topological susceptibility without restricting the ultra-violet cutoff below the hadronic scale.

  3. Regularization dependence on phase diagram in Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Kohyama, H.; Kimura, D.; Inagaki, T.

    2015-07-01

    We study the regularization dependence on meson properties and the phase diagram of quark matter by using the two flavor Nambu-Jona-Lasinio model. The model also has the parameter dependence in each regularization, so we explicitly give the model parameters for some sets of the input observables, then investigate its effect on the phase diagram. We find that the location or the existence of the critical end point highly depends on the regularization methods and the model parameters. Then we think that regularization and parameters are carefully considered when one investigates the QCD critical end point in the effective model studies.

  4. Polyakov loop extended Nambu-Jona-Lasinio model with imaginary chemical potential

    SciTech Connect

    Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu; Kouno, Hiroaki

    2008-03-01

    The Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model with imaginary chemical potential is studied. The model possesses the extended Z{sub 3} symmetry that QCD does. Quantities invariant under the extended Z{sub 3} symmetry, such as the partition function, the chiral condensate, and the modified Polyakov loop, have Roberge-Weiss periodicity. The phase diagram of confinement/deconfinement transition derived with the PNJL model is consistent with the Roberge-Weiss prediction on it and the results of lattice QCD. The phase diagram of chiral transition is also presented by the PNJL model.

  5. Pion-photon transition distribution amplitudes in the Nambu Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Courtoy, A.; Noguera, S.

    2007-11-01

    We define the pion-photon transition distribution amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism to the Nambu Jona-Lasinio model, as a realistic theory of the pion. The obtained vector and axial TDAs satisfy all features required by general considerations. In particular, sum rules and the polynomiality condition are explicitly verified. We have numerically proved that the odd coefficients in the polynomiality expansion of the vector TDA vanish in the chiral limit. The role of PCAC and the presence of a pion pole are explicitly shown.

  6. Susceptibilities and critical exponents within the Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Du, Yi-Lun; Lu, Ya; Xu, Shu-Sheng; Cui, Zhu-Fang; Shi, Chao; Zong, Hong-Shi

    2015-12-01

    In the mean field approximation of (2 + 1)-flavor Nambu-Jona-Lasinio model, we strictly derive several sets of coupled equations for the chiral susceptibility, the quark number susceptibility, etc. at finite temperature and quark chemical potential. The critical exponents of these susceptibilities in the vicinity of the QCD critical end point (CEP) are presented in SU(2) and SU(3) cases, respectively. It is found that these various susceptibilities share almost the same critical behavior near the CEP. The comparisons between the critical exponents for the order parameters and the theoretical predictions are also included.

  7. [Which ethics for medical ethics? Homage to Hans Jonas, 1903-1993].

    PubMed

    Munzarová, Marta

    2014-01-01

    Hans Jonas, one of the greatest philosophers of the 20th century, devoted several studies to the ethics in context with medicine and/or to the new biomedical research. His main thoughts in this field are presented (death and dying, mortality, reflections on experimenting with human subjects - nontherapeutic research, cloning, chimaeras). He was a man of wisdom and his humanity and moral sensibility are a matter of admiration. His ethics is in full consent with ethics and the dignity of medical profession. His ideas are compared (and contrasted) with those of the new bio"ethics". PMID:25370772

  8. Pion-photon transition distribution amplitudes in the Nambu-Jona-Lasinio model

    SciTech Connect

    Courtoy, A.; Noguera, S.

    2007-11-01

    We define the pion-photon transition distribution amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism to the Nambu-Jona-Lasinio model, as a realistic theory of the pion. The obtained vector and axial TDAs satisfy all features required by general considerations. In particular, sum rules and the polynomiality condition are explicitly verified. We have numerically proved that the odd coefficients in the polynomiality expansion of the vector TDA vanish in the chiral limit. The role of PCAC and the presence of a pion pole are explicitly shown.

  9. Average phase factor in the Polyakov-loop extended Nambu-Jona-Lasinio model

    SciTech Connect

    Sakai, Yuji; Sasaki, Takahiro; Yahiro, Masanobu; Kouno, Hiroaki

    2010-11-01

    The average phase factor } of the QCD determinant is evaluated at the finite quark chemical potential ({mu}{sub q}) with the two-flavor version of the Polyakov-loop extended Nambu-Jona-Lasinio model with the scalar-type eight-quark interaction. For {mu}{sub q} larger than half the pion mass m{sub {pi}} at vacuum, } is finite only when the Polyakov loop is larger than {approx}0.5, indicating that lattice QCD is feasible only in the deconfinement phase. A critical end point lies in the region of }=0. The scalar-type eight-quark interaction makes it shorter a relative distance of the critical end point to the boundary of the region. For {mu}{sub q}Jona-Lasinio model with dynamical mesonic fluctuations can reproduce lattice QCD data below the critical temperature.

  10. Dynamics and thermodynamics of a nonlocal Polyakov--Nambu--Jona-Lasinio model with running coupling

    SciTech Connect

    Hell, T.; Roessner, S.; Cristoforetti, M.; Weise, W.

    2009-01-01

    A nonlocal covariant extension of the two-flavor Nambu and Jona-Lasinio model is constructed, with built-in constraints from the running coupling of QCD at high-momentum and instanton physics at low-momentum scales. Chiral low-energy theorems and basic current algebra relations involving pion properties are shown to be reproduced. The momentum-dependent dynamical quark mass derived from this approach is in agreement with results from Dyson-Schwinger equations and lattice QCD. At finite temperature, inclusion of the Polyakov loop and its gauge invariant coupling to quarks reproduces the dynamical entanglement of the chiral and deconfinement crossover transitions as in the (local) Polyakov-loop-extended Nambu and Jona-Lasinio model, but now without the requirement of introducing an artificial momentum cutoff. Steps beyond the mean-field approximation are made including mesonic correlations through quark-antiquark ring summations. Various quantities of interest (pressure, energy density, speed of sound, etc.) are calculated and discussed in comparison with lattice QCD thermodynamics at zero chemical potential. The extension to finite quark chemical potential and the phase diagram in the (T,{mu})-plane are also discussed.

  11. The decay τ → K0K‑ντ in the extended Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Volkov, M. K.; Pivovarov, A. A.

    2016-07-01

    The full and differential widths of the decay τ → K0K‑ν τ are calculated in the framework of the extended Nambu-Jona-Lasinio model.The contributions of the subprocesses with the intermediate vector mesons ρ(770) and ρ(1450) are taken into account. The obtained results are in satisfactory agreement with the experimental data.

  12. Nonlocal Polyakov-Nambu-Jona-Lasinio model and imaginary chemical potential

    NASA Astrophysics Data System (ADS)

    Kashiwa, Kouji; Hell, Thomas; Weise, Wolfram

    2011-09-01

    With the aim of setting constraints for the modeling of the QCD phase diagram, the phase structure of the two-flavor Polyakov-loop-extended Nambu and Jona-Lasinio (PNJL) model is investigated in the range of imaginary chemical potentials (μI) and compared with available Nf=2 lattice QCD results. The calculations are performed using the advanced nonlocal version of the PNJL model with the inclusion of vector-type quasiparticle interactions between quarks, and with wave-function-renormalization corrections. It is demonstrated that the nonlocal PNJL model reproduces important features of QCD at finite μI, such as the Roberge-Weiss (RW) periodicity and the RW transition. Chiral and deconfinement transition temperatures for Nf=2 turn out to coincide both at zero chemical potential and at finite μI. Detailed studies are performed concerning the RW endpoint and its neighborhood where a first-order transition occurs.

  13. Beta function in the non-Abelian Nambu-Jona-Lasinio model in four dimensions

    SciTech Connect

    Alves, Van Sergio; Pinheiro, S. V. L.; Nascimento, Leonardo; Pena, Francisco

    2009-08-15

    In this paper we present the structure of the renormalization group in non-Abelian Nambu-Jona-Lasinio model up to 1-loop order. The model is not perturbatively renormalizable in the usual power counting sense, but it is treated as an effective theory, valid in a scale of energy in which p<<{lambda}, where p is the external momenta of the loop and {lambda} is a massive parameter that characterizes the couplings of the nonrenormalizable vertex. We clarify the tensorial structure of the interaction vertices and calculate the functions of the renormalization group. The analysis of the fixed points of the theory is also presented using Zimmermann's procedure for reducing the coupling constants. We find that the origin is an infrared-stable fixed point at low energies and also there is a nontrivial ultraviolet stable fixed point, indicating that the theory could be perturbatively investigated in the low momentum regime.

  14. Solitonic modulation and Lifshitz point in an external magnetic field within Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Cao, Gaoqing; Huang, Anping

    2016-04-01

    We study the inhomogeneous solitonic modulation of a chiral condensate within the effective Nambu-Jona-Lasinio model when a constant external magnetic field is present. The self-consistent Pauli-Villars regularization scheme is adopted to manipulate the ultraviolet divergence encountered in the thermodynamic quantities. In order to efficiently determine the chiral restoration lines, a new kind of Ginzburg-Landau expansion approach is proposed here. At zero temperature, we find that both the upper and lower boundaries of the solitonic modulation oscillate with the magnetic field in the μ - B phase diagram which is actually the de Hass-van Alphan (dHvA) oscillation. It is very interesting to find out how the tricritical Lifshitz point (TL,μL) evolves with the magnetic field: There are also dHvA oscillations in the TL- B and μL- B curves, though the tricritical temperature TL increases monotonically with the magnetic field.

  15. Calculating kaon fragmentation functions from the Nambu-Jona-Lasinio jet model

    SciTech Connect

    Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang

    2011-04-01

    The Nambu-Jona-Lasinio (NJL)-jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters. Earlier studies of the pion fragmentation functions using the NJL model within this framework showed qualitative agreement with the empirical parametrizations. Here we extend the NJL-jet model by including the strange quark. The corrections to the pion fragmentation functions and corresponding kaon fragmentation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation functions exhibit a qualitative agreement with the empirical parametrizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.

  16. Regions of different critical behavior of the two-flavor Nambu-Jona-Lasinio model

    SciTech Connect

    Xiong Juan; Jin Meng; Li Jiarong

    2011-02-15

    We study the chiral phase diagram in the T-{mu}-m{sub 0} space of the two-flavor Nambu-Jona-Lasinio model with the approach of the Landau theory of phase transitions. The tricritical point (TCP) is an endpoint of a line of triple points as well as a crosspoint of three {lambda}-transition lines. These double characters bring the connective and consistent problem of a critical phenomenon at the TCP. There is a crossover region from normal critical to tricritical behavior near the TCP, no matter whether the current quark mass is zero or not. The critical exponents need to be renormalized when one approaches the TCP along the first-order phase-transition line.

  17. Thermodynamics of a three-flavor nonlocal Polyakov-Nambu-Jona-Lasinio model

    SciTech Connect

    Hell, T.; Roessner, S.; Cristoforetti, M.; Weise, W.

    2010-04-01

    The present work generalizes a nonlocal version of the Polyakov-loop-extended Nambu and Jona-Lasinio (PNJL) model to the case of three active quark flavors, with inclusion of the axial U(1) anomaly. Gluon dynamics is incorporated through a gluonic background field, expressed in terms of the Polyakov loop. The thermodynamics of the nonlocal PNJL model accounts for both chiral and deconfinement transitions. Our results obtained in mean-field approximation are compared to lattice QCD results for N{sub f}=2+1 quark flavors. Additional pionic and kaonic contributions to the pressure are calculated in random phase approximation. Finally, this nonlocal three-flavor PNJL model is applied to the finite density region of the QCD phase diagram. It is confirmed that the existence and location of a critical point in this phase diagram depend sensitively on the strength of the axial U(1) breaking interaction.

  18. Thermal evolution of hybrid stars within the framework of a nonlocal Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    de Carvalho, S. M.; Negreiros, R.; Orsaria, M.; Contrera, G. A.; Weber, F.; Spinella, W.

    2015-09-01

    We study the thermal evolution of neutron stars containing deconfined quark matter in their core. Such objects are generally referred to as quark-hybrid stars. The confined hadronic matter in their core is described in the framework of nonlinear relativistic nuclear field theory. For the quark phase we use a nonlocal extension of the SU(3) Nambu-Jona-Lasinio model with vector interactions. The Gibbs condition is used to model phase equilibrium between confined hadronic matter and deconfined quark matter. Our study indicates that high-mass neutron stars may contain between 35 and 40% deconfined quark-hybrid matter in their cores. Neutron stars with canonical masses of around 1.4 M⊙ would not contain deconfined quark matter. The central proton fractions of the stars are found to be high, enabling them to cool rapidly. Very good agreement with the temperature evolution established for the neutron star in Cassiopeia A (Cas A) is obtained for one of our models (based on the popular NL3 nuclear parametrization), if the protons in the core of our stellar models are strongly paired, the repulsion among the quarks is mildly repulsive, and the mass of Cas A has a canonical value of 1.4 M⊙ .

  19. Chirally symmetric O(1/N{sub c}) corrections to the Nambu-Jona-Lasinio model

    SciTech Connect

    Dmitrasinovic, V.; Schulze, H.J.; Tegen, R.

    1995-03-01

    We develop an extended chirally symmetric self-consistent approximation scheme to the Nambu-Jona-Lasinio model, that corresponds to O(1/N{sub c}) corrections to the usual Hartree + random phase approximations. This scheme amounts to adding {open_quotes}meson cloud{close_quotes} contributions self-consistently to the quark self-energy and the meson polarization functions in a manner suggested by the weakly interacting nature of the quark and collective meson degrees of freedom of the NJL model in the large N{sub c} limit. We demonstrate explicitly that this scheme fulfills all the chiral symmetry theorems, namely the Goldstone theorem, the Goldberger-Treiman relation, and the conservation of the quark axial current. We explore the corrections to the quark self-energy and scalar condensate, as well as to the pion polarization function and the weak decay constant N{sub n}. The numerical evaluation of these corrections is presented and discussed. 23 refs., 14 figs., 2 tabs.

  20. Deconfinement of neutron star matter within the Nambu-Jona-Lasinio model

    SciTech Connect

    Lugones, G.; Grunfeld, A. G.; Scoccola, N. N.; Villavicencio, C.

    2009-08-15

    We study the deconfinement transition of hadronic matter into quark matter under neutron star conditions assuming color and flavor conservation during the transition. We use a two-phase description. For the hadronic phase we use different parametrizations of a nonlinear Walecka model which includes the whole baryon octet. For the quark-matter phase we use an SU(3){sub f} Nambu-Jona-Lasinio effective model including color superconductivity. Deconfinement is considered to be a first order phase transition that conserves color and flavor. It gives a short-lived transitory colorless-quark phase that is not in {beta} equilibrium, and decays to a stable configuration in {tau}{approx}{tau}{sub weak}{approx}10{sup -8} s. However, in spite of being very short lived, the transition to this intermediate phase determines the onset of the transition inside neutron stars. We find the transition free-energy density for temperatures typical of neutron star interiors. We also find the critical mass above which compact stars should contain a quark core and below which they are safe with respect to a sudden transition to quark matter. Rather independently on the stiffness of the hadronic equation of state (EOS) we find that the critical mass of hadronic stars (without trapped neutrinos) is in the range of {approx}1.5-1.8 solar masses. This is in coincidence with previous results obtained within the MIT bag model.

  1. Deconfinement transition in protoneutron stars: Analysis within the Nambu-Jona-Lasinio model

    SciTech Connect

    Lugones, G.; Carmo, T. A. S. do; Grunfeld, A. G.; Scoccola, N. N.

    2010-04-15

    We study the effect of color superconductivity and neutrino trapping on the deconfinement transition of hadronic matter into quark matter in a protoneutron star. To describe the strongly interacting matter a two-phase picture is adopted. For the hadronic phase we use different parametrizations of a nonlinear Walecka model which includes the whole baryon octet. For the quark-matter phase we use an SU(3){sub f} Nambu-Jona-Lasinio effective model which includes color superconductivity. We impose color and flavor conservation during the transition in such a way that just deconfined quark matter is transitorily out of equilibrium with respect to weak interactions. We find that deconfinement is more difficult for small neutrino content and it is easier for lower temperatures although these effects are not too large. In addition they will tend to cancel each other as the protoneutron star cools and deleptonizes, resulting a transition density that is roughly constant along the evolution of the protoneutron star. According to these results the deconfinement transition is favored after substantial cooling and contraction of the protoneutron star.

  2. Thermodynamics and quark susceptibilities: A Monte Carlo approach to the Polyakov-Nambu-Jona-Lasinio model

    SciTech Connect

    Cristoforetti, M.; Hell, T.; Klein, B.; Weise, W.

    2010-06-01

    The Monte-Carlo method is applied to the Polyakov-loop extended Nambu-Jona-Lasinio model. This leads beyond the saddle-point approximation in a mean-field calculation and introduces fluctuations around the mean fields. We study the impact of fluctuations on the thermodynamics of the model, both in the case of pure gauge theory and including two quark flavors. In the two-flavor case, we calculate the second-order Taylor expansion coefficients of the thermodynamic grand canonical partition function with respect to the quark chemical potential and present a comparison with extrapolations from lattice QCD. We show that the introduction of fluctuations produces only small changes in the behavior of the order parameters for chiral symmetry restoration and the deconfinement transition. On the other hand, we find that fluctuations are necessary in order to reproduce lattice data for the flavor nondiagonal quark susceptibilities. Of particular importance are pion fields, the contribution of which is strictly zero in the saddle point approximation.

  3. Nonlocal Ployakov-Nambu-Jona-Lasinio model and imaginary chemical potential

    SciTech Connect

    Kashiwa K.; Hell, T.; Weise, W.

    2011-09-21

    With the aim of setting constraints for the modeling of the QCD phase diagram, the phase structure of the two-flavor Polyakov-loop-extended Nambu and Jona-Lasinio (PNJL) model is investigated in the range of imaginary chemical potentials ({mu}{sub I}) and compared with available N{sub f} = 2 lattice QCD results. The calculations are performed using the advanced nonlocal version of the PNJL model with the inclusion of vector-type quasiparticle interactions between quarks, and with wave-function-renormalization corrections. It is demonstrated that the nonlocal PNJL model reproduces important features of QCD at finite {mu}{sub I}, such as the Roberge-Weiss (RW) periodicity and the RW transition. Chiral and deconfinement transition temperatures for N{sub f} = 2 turn out to coincide both at zero chemical potential and at finite {mu}{sub I}. Detailed studies are performed concerning the RW endpoint and its neighborhood where a first-order transition occurs.

  4. The SU(3)-Nambu-Jona-Lasinio soliton in the collective quantization formulation

    SciTech Connect

    Blotz, A.; Goeke, K. . Inst. for Nuclear Theory Inst. fuer Theoretische Physik 2, Ruhr-Univ. Bochum ); Diakonov, D.; Petrov, V.; Pobylitsa, P.V. ); Park, N.W. Center for Theoretical Physics, Seoul National Univ. (Korea, Republic

    1992-06-11

    On grounds of a semibosonized Nambu-Jona-Lasinio model, which has SU(3){sub R}{circle times}SU(3){sub L}-symmetry in the chiral limit, mass splittings for spin 1/2 and spin 3/2 baryons are studied in the presence of an explicit chiral symmetry breaking strange quark mass. To this aim these strangeness carrying baryons are understood as SU(3)-rotational excitations of an SU(2)-embedded soliton solution. Therefore, within the framework of collective quantization, the fermion determinant with the strange quark mass is expanded up to the second order in the flavor rotation velocity and up to the first order in this quark mass. Besides the strange and non-strange moments of inertia, which have some counterparts within the Skyrme model, some so-called anomalous moments of inertia are obtained. These call be related to the imaginary part of the effective Euclidian action and contain among others the anomalous baryon current. This is shown in a gradient expansion up to the first non-vanishing order. Together with the {Sigma}-commutator these are the solitonic ingredients of the collective hamiltonian, which is then diagonalized by means of strict perturbation theory in the strange quark mass and by the Yabu-Audo method. Both methods yield very good results for the masses of the spin 1/2 and 3/2 baryons. The former one reproduces some interesting mass formulas of Gell-Mann Okubo and Guadagnini and the latter one is able to describe the mass splittings up to a few MeV.

  5. The SU(3)-Nambu-Jona-Lasinio soliton in the collective quantization formulation

    SciTech Connect

    Blotz, A.; Goeke, K. |; Diakonov, D.; Petrov, V.; Pobylitsa, P.V.; Park, N.W. |

    1992-06-11

    On grounds of a semibosonized Nambu-Jona-Lasinio model, which has SU(3){sub R}{circle_times}SU(3){sub L}-symmetry in the chiral limit, mass splittings for spin 1/2 and spin 3/2 baryons are studied in the presence of an explicit chiral symmetry breaking strange quark mass. To this aim these strangeness carrying baryons are understood as SU(3)-rotational excitations of an SU(2)-embedded soliton solution. Therefore, within the framework of collective quantization, the fermion determinant with the strange quark mass is expanded up to the second order in the flavor rotation velocity and up to the first order in this quark mass. Besides the strange and non-strange moments of inertia, which have some counterparts within the Skyrme model, some so-called anomalous moments of inertia are obtained. These call be related to the imaginary part of the effective Euclidian action and contain among others the anomalous baryon current. This is shown in a gradient expansion up to the first non-vanishing order. Together with the {Sigma}-commutator these are the solitonic ingredients of the collective hamiltonian, which is then diagonalized by means of strict perturbation theory in the strange quark mass and by the Yabu-Audo method. Both methods yield very good results for the masses of the spin 1/2 and 3/2 baryons. The former one reproduces some interesting mass formulas of Gell-Mann Okubo and Guadagnini and the latter one is able to describe the mass splittings up to a few MeV.

  6. The phase diagram in the SU(3) Nambu-Jona-Lasinio model with 't Hooft and eight-quark interactions

    SciTech Connect

    Moreira, J.; Hiller, B.; Blin, A. H.; Osipov, A. A.

    2010-08-05

    It is shown that the endpoint of the first order transition line which merges into a crossover regime in the phase diagram of the Nambu--Jona-Lasinio model, extended to include the six-quark 't Hooft and eight-quark interaction Lagrangians, is pushed towards vanishing chemical potential and higher temperatures with increasing strength of the OZI-violating eight-quark interactions. We clarify a connection between the location of the endpoint in the phase diagram and the mechanism of chiral symmetry breaking at the quark level. Constraints on the coupling strengths based on groundstate stability and physical considerations are explained.

  7. Shear and bulk viscosities of quark matter from quark-meson fluctuations in the Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Ghosh, Sabyasachi; Peixoto, Thiago C.; Roy, Victor; Serna, Fernando E.; Krein, Gastão

    2016-04-01

    We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses and quark-meson couplings are obtained in the Nambu-Jona-Lasinio model. We found a nontrivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios η /s and ζ /s , where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasiparticle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η /s has a minimum very close to the quantum lower bound, η /s =1 /4 π .

  8. From scale properties of physical amplitudes to a predictive formulation of the Nambu-Jona-Lasinio model

    SciTech Connect

    Battistel, O. A.; Dallabona, G.

    2009-10-15

    The predictive power of the Nambu-Jona-Lasinio model is considered in the light of a novel strategy to handle the divergences typical of perturbative calculations. The referred calculational strategy eliminates unphysical dependencies on the arbitrary choices for the routing of internal momenta and symmetry violating terms. In the present work we extend a previous one on the same issue by including vector interactions and performing the discussion in a more general context: the role of scale arbitrariness for the consistency of the calculations is considered. We show that the imposition of arbitrary scale independence for the consistent regularized amplitudes lead to additional properties for the irreducible divergent objects. These properties allow us to parametrize the remaining freedom in terms of a unique constant where resides all the arbitrariness involved. By searching for the best value for the arbitrary parameter we find a critical condition for the existence of an acceptable physical value for the dynamically generated quark mass. Such critical condition fixes the remaining arbitrariness turning the Nambu-Jona-Lasinio into a predictive model in the sense that its phenomenological consequences do not depend on possible choices made in intermediary steps. Numerical results are obtained for physical quantities like the vector and axial-vector masses and their coupling constants as genuine predictions.

  9. Pion polarizability in the Nambu-Jona-Lasinio model and possibilities of its experimental studies in Coulomb nuclear scattering

    SciTech Connect

    Bystritskiy, Yu. M.; Guskov, A. V.; Pervushin, V. N.; Volkov, M. K.

    2009-12-01

    The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model, where the quark loops (in the mean field approximation) and the meson loops (in the 1/N{sub c} approximation) are taken into account. We show that quark loop contribution dominates because the meson loops strongly conceal each other. The sigma-pole contribution (m{sub {sigma}}{sup 2}-t){sup -1} plays the main role and contains strong t-dependence of the effective pion polarizability at the region |t|{>=}4M{sub {pi}}{sup 2}. Possibilities of experimental test of this sigma-pole effect in the reaction of Coulomb nuclear scattering are estimated for the COMPASS experiment.

  10. Neutron stars: From the inner crust to the core with the (extended) Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Pais, Helena; Menezes, Débora P.; Providência, Constança

    2016-06-01

    Nucleonic matter is described within an SU(2) extended Nambu-Jona-Lasinio (NJL) model. Several parametrizations with different nuclear matter saturation properties are proposed. At subsaturation, nuclear pasta phases are calculated within two methods: the coexistence-phases approximation and the compressible liquid drop model, with the surface tension coefficient determined using a geometrical approach at zero temperature. A unified equation of state of stellar matter for the inner crust, with the nuclear pasta phases, and the core is calculated. The mass and radius of neutron stars within this framework are obtained for several families of hadronic and hybrid stars. The quark phase of hybrid stars is described within the SU(3) NJL model including a vector term. Stellar macroscopic properties are in accordance with some of the recent results in the literature.

  11. Phase diagram of baryon matter in the SU(2) Nambu – Jona-Lasinio model with a Polyakov loop

    NASA Astrophysics Data System (ADS)

    Kalinovsky, Yu L.; Toneev, V. D.; Friesen, A. V.

    2016-04-01

    The nature of phase transitions in hot and dense nuclear matter is discussed in the framework of the effective SU(2) Nambu – Jona-Lasinio model with a Polyakov loop with two quark flavor — one of a few models describing the properties of both chiral and confinement-deconfinement phase transitions. We consider the parameters of the model and examine additional interactions that influence the structure of the phase diagram and the positions of critical points in it. The effect of meson correlations on the thermodynamic properties of the quark-meson system is examined. The evolution of the model with changes in the understanding of the phase diagram structure is discussed.

  12. BCS, Nambu-Jona-Lasinio, and Han-Nambu: A sketch of Nambu's works in 1960-1965

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo

    2016-06-01

    The years 1960-1965 were a remarkable period for Yoichiro Nambu. Starting with a reformulation of BCS theory with emphasis on gauge invariance, he recognized the realization of spontaneous chiral symmetry breaking in particle physics as evidenced by the Goldberger-Treiman relation. A concrete model of Nambu and Jona-Lasinio illustrated the essence of the Nambu-Goldstone theorem and the idea of soft pions. After the proposal of the quark model by Gell-Mann, he together with Han constructed an alternative model of integrally charged quarks with possible non-Abelian gluons. All these remarkable works were performed during the years 1960-1965. Here I briefly review those works following the original papers of Nambu chronologically, together with a brief introduction to a formulation of Noether's theorem and the Ward-Takahashi identities using path integrals. This article is mostly based on a lecture given at the Nambu Memorial Symposium held at Osaka City University in September 2015, where Nambu started his professional career.

  13. Extension of the Nambu Jona-Lasinio model predictions at high densities and temperatures using an implicit regularization scheme

    NASA Astrophysics Data System (ADS)

    Farias, R. L. S.; Dallabona, G.; Krein, G.; Battistel, O. A.

    2008-06-01

    Traditional cutoff regularization schemes of the Nambu Jona-Lasinio model limit the applicability of the model to energy-momentum scales much below the value of the regularizing cutoff. In particular, the model cannot be used to study quark matter with Fermi momenta larger than the cutoff. In the present work, an extension of the model to high temperatures and densities recently proposed by Casalbuoni, Gatto, Nardulli, and Ruggieri is used in connection with an implicit regularization scheme. This is done by making use of scaling relations of the divergent one-loop integrals that relate these integrals at different energy-momentum scales. Fixing the pion decay constant at the chiral symmetry breaking scale in the vacuum, the scaling relations predict a running coupling constant that decreases as the regularization scale increases, implementing in a schematic way the property of asymptotic freedom of quantum chromodynamics. If the regularization scale is allowed to increase with density and temperature, the coupling will decrease with density and temperature, extending in this way the applicability of the model to high densities and temperatures. These results are obtained without specifying an explicit regularization. As an illustration of the formalism, numerical results are obtained for the finite density and finite temperature quark condensate and applied to the problem of color superconductivity at high quark densities and finite temperature.

  14. Constant-sound-speed parametrization for Nambu-Jona-Lasinio models of quark matter in hybrid stars

    NASA Astrophysics Data System (ADS)

    Ranea-Sandoval, Ignacio F.; Han, Sophia; Orsaria, Milva G.; Contrera, Gustavo A.; Weber, Fridolin; Alford, Mark G.

    2016-04-01

    The discovery of pulsars as heavy as 2 solar masses has led astrophysicists to rethink the core compositions of neutron stars, ruling out many models for the nuclear equations of state (EoS). We explore the hybrid stars that occur when hadronic matter is treated in a relativistic mean-field approximation and quark matter is modeled by three-flavor local and nonlocal Nambu-Jona-Lasinio (NJL) models with repulsive vector interactions. The NJL models typically yield equations of state that feature a first-order transition to quark matter. Assuming that the quark-hadron surface tension is high enough to disfavor mixed phases and restricting to EoSs that allow stars to reach 2 solar masses, we find that the appearance of the quark-matter core either destabilizes the star immediately (this is typical for nonlocal NJL models) or leads to a very short hybrid star branch in the mass-radius relation (this is typical for local NJL models). Using the constant-sound-speed parametrization we can see that the reason for the near absence of hybrid stars is that the transition pressure is fairly high and the transition is strongly first order.

  15. 2+1 flavor Polyakov Nambu Jona-Lasinio model at finite temperature and nonzero chemical potential

    NASA Astrophysics Data System (ADS)

    Fu, Wei-Jie; Zhang, Zhao; Liu, Yu-Xin

    2008-01-01

    We extend the Polyakov-loop improved Nambu Jona-Lasinio model to 2+1 flavor case to study the chiral and deconfinement transitions of strongly interacting matter at finite temperature and nonzero chemical potential. The Polyakov loop, the chiral susceptibility of light quarks (u and d), and the strange quark number susceptibility as functions of temperature at zero chemical potential are determined and compared with the recent results of lattice QCD simulations. We find that there is always an inflection point in the curve of strange quark number susceptibility accompanying the appearance of the deconfinement phase, which is consistent with the result of lattice QCD simulations. Predictions for the case at nonzero chemical potential and finite temperature are made as well. We give the phase diagram in terms of the chemical potential and temperature and find that the critical end point moves down to low temperature and finally disappears with the decrease of the strength of the ’t Hooft flavor-mixing interaction.

  16. Transverse-momentum-dependent fragmentation and quark distribution functions from the Nambu-Jona-Lasinio-jet model

    NASA Astrophysics Data System (ADS)

    Matevosyan, Hrayr H.; Bentz, Wolfgang; Cloët, Ian C.; Thomas, Anthony W.

    2012-01-01

    Using the model of Nambu and Jona-Lasinio to provide a microscopic description of both the structure of the nucleon and of the quark to hadron elementary fragmentation functions, we investigate the transverse-momentum dependence of the unpolarized quark distributions in the nucleon and of the quark to pion and kaon fragmentation functions. The transverse-momentum dependence of the fragmentation functions is determined within a Monte Carlo framework, with the notable result that the average P⊥2 of the produced kaons is significantly larger than that of the pions. We also find that ⟨P⊥2⟩ has a sizable z dependence, in contrast with the naive Gaussian ansatz for the fragmentation functions. Diquark correlations in the nucleon give rise to a nontrivial flavor dependence in the unpolarized transverse-momentum-dependent quark distribution functions. The ⟨kT2⟩ of the quarks in the nucleon are also found to have a sizable x dependence. Finally, these results are used as input to a Monte Carlo event generator for semi-inclusive deep inelastic scattering (SIDIS), which is used to determine the average transverse momentum squared of the produced hadrons measured in SIDIS, namely, ⟨PT2⟩. Again, we find that the average PT2 of the produced kaons in SIDIS is significantly larger than that of the pions and in each case ⟨PT2⟩ has a sizable z dependence.

  17. Quark matter in an SU(3) Nambu-Jona-Lasinio model with two types of vector interactions

    NASA Astrophysics Data System (ADS)

    Chu, Peng-Cheng; Wang, Bin; Ma, Hong-Yang; Dong, Yu-Min; Chang, Su-Ling; Zheng, Chun-Hong; Liu, Jun-Ting; Zhang, Xiao-Min

    2016-05-01

    We investigate the properties of asymmetric quark matter and strange quark matter in the framework of the SU(3) Nambu-Jona-Lasinio (NJL) model with two types of vector interactions: (1) the flavor-dependent repulsion among different flavors of quarks with the coupling constant GV , and (2) the universal repulsion and the vector-isovector interaction among different flavors of quarks with the coupling constants gV and GI V. Using these two types of vector interactions in the NJL model, we study the quark symmetry energy in asymmetric quark matter, the constituent quark mass, the quark fraction, the equation of state in strange quark matter, the maximum mass of a quark star, and the properties of the QCD phase diagram. We find that including the two types of vector interactions in the SU(3) NJL model can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. In particular, our results indicate that we can describe PSR J 1614 -2230 and PSR J 0348 +0432 as quark stars by considering the universal repulsion and the vector-isovector interaction among quark matter in the SU(3) NJL model.

  18. Spinodal instabilities of baryon-rich quark-gluon plasma in the Polyakov-Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Li, Feng; Ko, Che Ming

    2016-03-01

    Using the Polyakov-Nambu-Jona-Lasinio model, we study the spinodal instability of a baryon-rich quark-gluon plasma in the linear response theory. We find that the spinodal unstable region in the temperature and density plane shrinks with increasing wave number of the unstable mode and is also reduced if the effect of the Polyakov loop is not included. In the small wave number or long wavelength limit, the spinodal boundaries in both cases of with and without the Polyakov loop coincide with those determined from the isothermal spinodal instability in the thermodynamic approach. Also, the vector interactions among quarks are found to suppress unstable modes of all wave numbers. Moreover, the growth rate of unstable modes initially increases with the wave number but is reduced when the wave number becomes large. Including the collisional effect from quark scattering via the linearized Boltzmann equation, we further find that it decreases the growth rate of unstable modes of all wave numbers. The relevance of these results to relativistic heavy ion collisions is discussed.

  19. Collective modes and Kosterlitz-Thouless transition in a magnetic field in the planar Nambu–Jona-Lasinio model

    DOE PAGESBeta

    Cao, Gaoqing; He, Lianyi; Zhuang, Pengfei

    2014-09-15

    It is known that a constant magnetic field is a strong catalyst of dynamical chiral symmetry breaking in 2+1 dimensions, leading to generating dynamical fermion mass even at weakest attraction. In this work we investigate the collective modes associated with the dynamical chiral symmetry breaking in a constant magnetic field in the (2+1)-dimensional Nambu–Jona-Lasinio model with continuous U(1) chiral symmetry. We introduce a self-consistent scheme to evaluate the propagators of the collective modes at the leading order in 1/N. The contributions from the vacuum and from the magnetic field are separated such that we can employ the well-established regularization schememore » for the case of vanishing magnetic field. The same scheme can be applied to the study of the next-to-leading order correction in 1/N. We show that the sigma mode is always a lightly bound state with its mass being twice the dynamical fermion mass for arbitrary strength of the magnetic field. Since the dynamics of the collective modes is always 2+1 dimensional, the finite temperature transition should be of the Kosterlitz-Thouless (KT) type. We determine the KT transition temperature TKT as well as the mass melting temperature T* as a function of the magnetic field. It is found that the pseudogap domain TKT < T < T* is enlarged with increasing strength of the magnetic field. The influence of a chiral imbalance or axial chemical potential μ5 is also studied. We find that even a constant axial chemical potential μ5 can lead to inverse magnetic catalysis of the KT transition temperature in 2+1 dimensions. As a result, the inverse magnetic catalysis behavior is actually the de Haas–van Alphen oscillation induced by the interplay between the magnetic field and the Fermi surface.« less

  20. Collective modes and Kosterlitz-Thouless transition in a magnetic field in the planar Nambu–Jona-Lasinio model

    SciTech Connect

    Cao, Gaoqing; He, Lianyi; Zhuang, Pengfei

    2014-09-15

    It is known that a constant magnetic field is a strong catalyst of dynamical chiral symmetry breaking in 2+1 dimensions, leading to generating dynamical fermion mass even at weakest attraction. In this work we investigate the collective modes associated with the dynamical chiral symmetry breaking in a constant magnetic field in the (2+1)-dimensional Nambu–Jona-Lasinio model with continuous U(1) chiral symmetry. We introduce a self-consistent scheme to evaluate the propagators of the collective modes at the leading order in 1/N. The contributions from the vacuum and from the magnetic field are separated such that we can employ the well-established regularization scheme for the case of vanishing magnetic field. The same scheme can be applied to the study of the next-to-leading order correction in 1/N. We show that the sigma mode is always a lightly bound state with its mass being twice the dynamical fermion mass for arbitrary strength of the magnetic field. Since the dynamics of the collective modes is always 2+1 dimensional, the finite temperature transition should be of the Kosterlitz-Thouless (KT) type. We determine the KT transition temperature TKT as well as the mass melting temperature T* as a function of the magnetic field. It is found that the pseudogap domain TKT < T < T* is enlarged with increasing strength of the magnetic field. The influence of a chiral imbalance or axial chemical potential μ5 is also studied. We find that even a constant axial chemical potential μ5 can lead to inverse magnetic catalysis of the KT transition temperature in 2+1 dimensions. As a result, the inverse magnetic catalysis behavior is actually the de Haas–van Alphen oscillation induced by the interplay between the magnetic field and the Fermi surface.

  1. Evaluating the phase diagram at finite isospin and baryon chemical potentials in the Nambu-Jona-Lasinio model

    SciTech Connect

    Mu Chengfu; He Lianyi; Liu Yuxin

    2010-09-01

    We study the phase diagram of two-flavor dense QCD at finite isospin and baryon chemical potentials in the framework of the Nambu-Jona-Lasinio model. We focus on the case with arbitrary isospin chemical potential {mu}{sub I} and small baryon chemical potential {mu}{sub B{<=}{mu}B}{sup {chi}}where {mu}{sub B}{sup {chi}}is the critical chemical potential for the first-order chiral phase transition to happen at {mu}{sub I}=0. The {mu}{sub I}-{mu}{sub B} phase diagram shows a rich phase structure since the system undergoes a crossover from a Bose-Einstein condensate of charged pions to a BCS superfluid with condensed quark-antiquark Cooper pairs when {mu}{sub I} increases at {mu}{sub B}=0, and a nonzero baryon chemical potential serves as a mismatch between the pairing species. We observe a gapless pion condensation phase near the quadruple point ({mu}{sub I},{mu}{sub B})=(m{sub {pi}},M{sub N}-1.5m{sub {pi}}) where m{sub {pi}}, M{sub N} are the vacuum masses of pions and nucleons, respectively. The first-order chiral phase transition becomes a smooth crossover when {mu}{sub I}>0.82m{sub {pi}}. At very large isospin chemical potential, {mu}{sub I}>6.36m{sub {pi}}, an inhomogeneous Larkin-Ovchinnikov-Fulde-Ferrell superfluid phase, appears in a window of {mu}{sub B}, which should in principle exist for arbitrary large {mu}{sub I}. Between the gapless and the Larkin-Ovchinnikov-Fulde-Ferrell phases, the pion superfluid phase and the normal quark matter phase are connected by a first-order phase transition. In the normal phase above the superfluid domain, we find that charged pions are still bound states even though {mu}{sub I} becomes very large, which is quite different from that at finite temperature. Our phase diagram is in good agreement with that found in imbalanced cold atom systems.

  2. Anders Jonas Ångström and the foundation of spectroscopy - Commemorative article on the second centenary of his birth

    NASA Astrophysics Data System (ADS)

    Reif-Acherman, Simón

    2014-12-01

    The Swedish astronomer Anders Jonas Ångström, born two centuries ago and professor of physics at Uppsala University, was one of the founders of optical spectroscopy. By using diffraction gratings out of glass plates with fine scorings across the face, he was able to observe the spectrum of the Sun, announcing in 1862 that he had discovered the lines of hydrogen in the solar spectrum. His most important work, 'Recherches sur la Spectre Solaire', including an atlas of close to a thousand spectral lines, became the standard of spectroscopy for at least a quarter of a century. This article deals with his life as well as his main contributions to the development of several areas of physical science, stressing his pioneer activities in spectroscopy.

  3. Radiative decays of radially excited mesons {pi}{sup 0'}, {rho}{sup 0'}, and {omega}{sup '} in the Nambu-Jona-Lasinio model

    SciTech Connect

    Kuraev, E. A.; Volkov, M. K.; Arbuzov, A. B.

    2010-12-15

    Radiative decays {pi}{sup 0}({pi}{sup 0'}){yields}{gamma}+{gamma}, {pi}{sup 0'{yields}{rho}0}({omega})+{gamma}, {rho}{sup 0'}({omega}{sup '}){yields}{pi}{sup 0}+{gamma}, and {rho}{sup 0'}({omega}{sup '}){yields}{pi}{sup 0'}+{gamma} are considered in the framework of the SU(2)xSU(2) Nambu-Jona-Lasinio (NJL) model. Radially excited mesons are described with the help of a simple polynomial form factor. In spite of mixing of the ground and excited meson states in this model, the decay widths of {pi}{sup 0{yields}{gamma}}+{gamma} and {rho}{sup 0}({omega}){yields}{pi}{sup 0}+{gamma} are found to be in good agreement with experimental data, as in the standard NJL model. Our predictions for decay widths of radially excited mesons can be verified in future experiments.

  4. Role of two-flavor color superconductor pairing in a three-flavor Nambu-Jona-Lasinio model with axial anomaly

    SciTech Connect

    Basler, H.; Buballa, M.

    2010-11-01

    The phase diagram of strongly interacting matter is studied within a three-flavor Nambu-Jona-Lasinio model, which contains the coupling between chiral and diquark condensates through the axial anomaly. Our results show that it is essential to include the two-flavor color superconducting (2SC) phase in the analysis. While this is expected for realistic strange-quark masses, we find that even for equal up, down, and strange bare quark masses 2SC pairing can be favored due to spontaneous flavor symmetry breaking by the axial anomaly. This can lead to a rich phase structure, including BCS- and Bose-Einstein condensate-like 2SC and color-flavor locked phases and new endpoints. On the other hand, the low-temperature critical endpoint, which was found earlier in the same model without 2SC pairing, is almost removed from the phase diagram and cannot be reached from the low-density chirally broken phase without crossing a preceding first-order phase boundary. For physical quark masses no additional critical endpoint is found.

  5. Aspects of U {sub A} (1) breaking in the Nambu and Jona-Lasinio model

    SciTech Connect

    Osipov, A.A. . E-mail: osipov@nusun.jinr.ru; Hiller, B. . E-mail: brigitte@teor.fis.uc.pt; Bernard, V. . E-mail: bernard@lpt6.u-strasbg.fr; Blin, A.H. . E-mail: alex@teor.fis.uc.pt

    2006-11-15

    The six-quark instanton induced 't Hooft interaction, which breaks the unwanted U {sub A} (1) symmetry of QCD, is a source of perturbative corrections to the leading order result formed by the four-quark forces with the U {sub L} (3) x U {sub R} (3) chiral symmetry. A detailed quantitative calculation is carried out to bosonize the model by the functional integral method. We concentrate our efforts on finding ways to integrate out the auxiliary bosonic variables. The functional integral over these variables cannot be evaluated exactly. We show that the modified stationary phase approach leads to a resummation within the perturbative series and calculate the integral in the 'two-loop' approximation. The result is a correction to the effective mesonic Lagrangian which may be important for the low-energy spectrum and dynamics of the scalar and pseudoscalar nonets.

  6. The complete mitogenome of the marine bivalve Lutraria rhynchaena Jonas 1844 (Heterodonta: Bivalvia: Mactridae).

    PubMed

    Gan, Han Ming; Tan, Mun Hua; Thai, Binh Thanh; Austin, Christopher M

    2016-01-01

    The complete mitochondrial genome of the commercially important snout otter clam Lutraria rhynchaena was obtained from low-coverage shotgun sequencing data on the MiSeq platform. The L. rhynchaena mitogenome has 16,927 base pairs (69% A + T content) and made up of 12 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 953 bp non-coding AT-rich region. This is the first mitogenome to be sequenced from the genus Lutraria, and the seventh to be reported for the family Mactridae. PMID:24617474

  7. Relativistic BEC-BCS Crossover in a magnetized Nambu-Jona-Lasinio Model

    NASA Astrophysics Data System (ADS)

    Duarte, Dyana C.; Farias, R. L. S.; Manso, Pedro H. A.; Ramos, Rudnei O.

    2016-04-01

    The BEC-BCS crossover in the NJL model is studied in the presence of an external magnetic field. Particular attention is given to two different regularization schemes used in the literature and we show how they compare to each other. The comparison is made for the case of a cold and magnetized two color NJL model. We also make a brief discussion about the Nc = 3 case without magnetic fields, as an extension of this work in the future.

  8. Nonlocal Polyakov-Nambu-Jona-Lasinio model with wave function renormalization at finite temperature and chemical potential

    SciTech Connect

    Contrera, G. A.; Orsaria, M.; Scoccola, N. N.

    2010-09-01

    We study the phase diagram of strongly interacting matter in the framework of a nonlocal SU(2) chiral quark model which includes wave function renormalization and coupling to the Polyakov loop. Both nonlocal interactions based on the frequently used exponential form factor, and on fits to the quark mass and renormalization functions obtained in lattice calculations are considered. Special attention is paid to the determination of the critical points, both in the chiral limit and at finite quark mass. In particular, we study the position of the critical end point as well as the value of the associated critical exponents for different model parametrizations.

  9. Characterisation of 12 microsatellite loci in the Vietnamese commercial clam Lutraria rhynchaena Jonas 1844 (Heterodonta: Bivalvia: Mactridae) through next-generation sequencing.

    PubMed

    Thai, Binh Thanh; Tan, Mun Hua; Lee, Yin Peng; Gan, Han Ming; Tran, Trang Thi; Austin, Christopher M

    2016-05-01

    The marine clam Lutraria rhynchaena is gaining popularity as an aquaculture species in Asia. Lutraria populations are present in the wild throughout Vietnam and several stocks have been established and translocated for breeding and aquaculture grow-out purposes. In this study, we demonstrate the feasibility of utilising Illumina next-generation sequencing technology to streamline the identification and genotyping of microsatellite loci from this clam species. Based on an initial partial genome scan, 48 microsatellite markers with similar melting temperatures were identified and characterised. The 12 most suitable polymorphic loci were then genotyped using 51 individuals from a population in Quang Ninh Province, North Vietnam. Genetic variation was low (mean number of alleles per locus = 2.6; mean expected heterozygosity = 0.41). Two loci showed significant deviation from Hardy-Weinberg equilibrium (HWE) and the presence of null alleles, but there was no evidence of linkage disequilibrium among loci. Three additional populations were screened (n = 7-36) to test the geographic utility of the 12 loci, which revealed 100 % successful genotyping in two populations from central Vietnam (Nha Trang). However, a second population from north Vietnam (Co To) could not be successfully genotyped and morphological evidence and mitochondrial variation suggests that this population represents a cryptic species of Lutraria. Comparisons of the Qang Ninh and Nha Trang populations, excluding the 2 loci out of HWE, revealed statistically significant allelic variation at 4 loci. We reported the first microsatellite loci set for the marine clam Lutraria rhynchaena and demonstrated its potential in differentiating clam populations. Additionally, a cryptic species population of Lutraria rhynchaena was identified during initial loci development, underscoring the overlooked diversity of marine clam species in Vietnam and the need to genetically characterise population representatives prior to microsatellite development. The rapid identification and validation of microsatellite loci using next-generation sequencing technology warrant its integration into future microsatellite loci development for key aquaculture species in Vietnam and more generally, aquaculture countries in the South East Asia region. PMID:26922181

  10. Short-term exposure to high-pressure ventilation leads to pulmonary biotrauma and systemic inflammation in the rat.

    PubMed

    Hoegl, Sandra; Boost, Kim A; Flondor, Michael; Scheiermann, Patrick; Muhl, Heiko; Pfeilschifter, Josef; Zwissler, Bernhard; Hofstetter, Christian

    2008-04-01

    Though often lifesaving, mechanical ventilation itself bears the risk of lung damage [ventilator-induced lung injury (VILI)]. The underlying molecular mechanisms have not been fully elucidated, but stress-induced mediators seem to play an important role in biotrauma related to VILI. Our purpose was to evaluate an animal model of VILI that allows the observation of pathophysiologic changes along with parameters of biotrauma. For VILI induction, rats (n=16) were ventilated with a peak airway pressure (pmax) of 45 cm H2O and end-expiratory pressure (PEEP) of 0 for 20 min, followed by an observation time of 4 h. In the control group (n=8) the animals were ventilated with a pmax of 20 cm H2O and PEEP of 4. High-pressure ventilation resulted in an increase in paCO2 and a decrease in paO2 and mean arterial pressure. Only 4 animals out of 16 survived 4 h and VILI lungs showed severe macroscopic and microscopic damage, oedema and neutrophil influx. High-pressure ventilation increased the cytokine levels of macrophage inflammatory protein-2 and IL-1beta in bronchoalveolar lavage and plasma. VILI also induced pulmonary heat shock protein-70 expression and the activity of matrix metalloproteinases. The animal model used enabled us to observe the effect of high-pressure ventilation on mortality, lung damage/function and biotrauma. Thus, by combining barotrauma with biotrauma, this animal model may be suitable for studying therapeutical approaches to VILI. PMID:18360698

  11. Ventilator-induced Lung Injury

    PubMed Central

    Kneyber, Martin C. J.; Zhang, Haibo; Slutsky, Arthur S.

    2016-01-01

    It is well established that mechanical ventilation can injure the lung, producing an entity known as ventilator-induced lung injury (VILI). There are various forms of VILI, including volutrauma (i.e., injury caused by overdistending the lung), atelectrauma (injury due to repeated opening/closing of lung units), and biotrauma (release of mediators that can induce lung injury or aggravate pre-existing injury, potentially leading to multiple organ failure). Experimental data in the pediatric context are in accord with the importance of VILI, and appear to show age-related susceptibility to VILI, although a conclusive link between use of large Vts and mortality has not been demonstrated in this population. The relevance of VILI in the pediatric intensive care unit population is thus unclear. Given the physiological and biological differences in the respiratory systems of infants, children, and adults, it is difficult to directly extrapolate clinical practice from adults to children. This Critical Care Perspective analyzes the relevance of VILI to the pediatric population, and addresses why pediatric patients might be less susceptible than adults to VILI. PMID:25003705

  12. Corrigendum to "Historical review: Anders Jonas Ångström and the foundation of spectroscopy - Commemorative article on the second centenary of his birth" [Spectrochim. Acta Part B, 102 (2014) 12-23

    NASA Astrophysics Data System (ADS)

    Reif-Acherman, Simón

    2015-07-01

    The following addendum should be added to the Acknowledgments of the above article. Due to the multiplicity of simultaneous activities in which I am continuously involved, I forgot mentioning that Prof. Dr. Klaus Hentschel, of the History Department of the University of Stuttgart (Germany) was helpful in obtaining some of the source material used in my review. In particular, Prof. Hentschel provided the scans of Anne Beckmann's work to which I was guided by passages in his book on "Mapping the spectrum", Oxford University Press (2002). I also followed his recommendation of contacting the Swedish historians of science, and Prof. Sven Widmalm among them; however, the correspondence was not successful.

  13. The Role of the Individual within Society: "The Giver" by Lois Lowry and "Brave New World" by Aldous Huxley. Thematic Unit.

    ERIC Educational Resources Information Center

    Tarner, Danielle; Umak, Adam

    Lois Lowry's award-winning novel, "The Giver," chronicles the strength of Jonas, an adolescent boy of 12 who lives in a utopian society. In the Community everyone is equal, and there is only a gray routine of existence. But Jonas is singled out by "The Giver," a wise old man who teaches Jonas the range of human emotions, and the two then plot the…

  14. SN50, a Cell-Permeable Inhibitor of Nuclear Factor-κB, Attenuates Ventilator-Induced Lung Injury in an Isolated and Perfused Rat Lung Model.

    PubMed

    Chian, Chih-Feng; Chiang, Chi-Huei; Chuang, Chiao-Hui; Liu, Shiou-Ling; Tsai, Chen-Liang

    2016-08-01

    High tidal volume (VT) ventilation causes the release of various mediators and results in ventilator-induced lung injury (VILI). SN50, a cell-permeable nuclear factor-κB (NF-κB) inhibitory peptide, attenuates inflammation and acute respiratory distress syndrome. However, the mechanisms associated with the effects of SN50 in VILI have not been fully elucidated. We investigated the cellular and molecular mechanisms for the effects of SN50 treatment in VILI. An isolated and perfused rat lung model was exposed to low (5 mL/kg) or high (15 mL/kg) VT ventilation for 6 h. SN50 was administered in the perfusate at the onset of the high-stretch mechanical ventilation. The hemodynamics, lung histological changes, inflammatory responses, and activation of apoptotic pathways were evaluated. VILI was demonstrated by increased pulmonary vascular permeability and lung weight gain, as well as by increased levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, myeloperoxidase (MPO), hydrogen peroxide, and macrophage inflammatory protein-2 in the bronchoalveolar lavage fluid. The lung tissue expression of TNF-α, IL-1β, mitogen-activated protein kinases (MAPKs), caspase-3, and phosphorylation of serine/threonine-specific protein kinase (p-AKT) was greater in the high VT group than in the low VT group. Upregulation and activation of NF-κB was associated with increased lung injury in VILI. SN50 attenuated the inflammatory responses, including the expression of IL-1β, TNF-α, MPO, MAPKs, and NF-κB. In addition, the downregulation of apoptosis was evaluated using caspase-3 and p-AKT expression. Furthermore, SN50 mitigated the increases in the lung weights, pulmonary vascular permeability, and lung injury. In conclusion, VILI is associated with inflammatory responses and activation of NF-κB. SN50 inhibits the activation of NF-κB and attenuates VILI. PMID:26780513

  15. Predicting ventilator-induced lung injury using a lung injury cost function.

    PubMed

    Hamlington, Katharine L; Smith, Bradford J; Allen, Gilman B; Bates, Jason H T

    2016-07-01

    Managing patients with acute respiratory distress syndrome (ARDS) requires mechanical ventilation that balances the competing goals of sustaining life while avoiding ventilator-induced lung injury (VILI). In particular, it is reasonable to suppose that for any given ARDS patient, there must exist an optimum pair of values for tidal volume (VT) and positive end-expiratory pressure (PEEP) that together minimize the risk for VILI. To find these optimum values, and thus develop a personalized approach to mechanical ventilation in ARDS, we need to be able to predict how injurious a given ventilation regimen will be in any given patient so that the minimally injurious regimen for that patient can be determined. Our goal in the present study was therefore to develop a simple computational model of the mechanical behavior of the injured lung in order to calculate potential injury cost functions to serve as predictors of VILI. We set the model parameters to represent normal, mildly injured, and severely injured lungs and estimated the amount of volutrauma and atelectrauma caused by ventilating these lungs with a range of VT and PEEP. We estimated total VILI in two ways: 1) as the sum of the contributions from volutrauma and atelectrauma and 2) as the product of their contributions. We found the product provided estimates of VILI that are more in line with our previous experimental findings. This model may thus serve as the basis for the objective choice of mechanical ventilation parameters for the injured lung. PMID:27174922

  16. Ecology and Pedagogy: On the Educational Implications of Postwar Environmental Philosophy

    ERIC Educational Resources Information Center

    Hotam, Yotam

    2010-01-01

    Environmentalism, an ethical imperative to preserve and protect nature, has become in the last decade a central ethical, political and pedagogic theme. Against this background, this article focuses on the postwar philosophy of the German-Jewish scholar Hans Jonas (1903-93). It points to Jonas's radical theory of pedagogic responsibility, and to…

  17. Beyond volutrauma in ARDS: the critical role of lung tissue deformation

    PubMed Central

    2011-01-01

    Ventilator-induced lung injury (VILI) consists of tissue damage and a biological response resulting from the application of inappropriate mechanical forces to the lung parenchyma. The current paradigm attributes VILI to overstretching due to very high-volume ventilation (volutrauma) and cyclic changes in aeration due to very low-volume ventilation (atelectrauma); however, this model cannot explain some research findings. In the present review, we discuss the relevance of cyclic deformation of lung tissue as the main determinant of VILI. Parenchymal stability resulting from the interplay of respiratory parameters such as tidal volume, positive end-expiratory pressure or respiratory rate can explain the results of different clinical trials and experimental studies that do not fit with the classic volutrauma/atelectrauma model. Focusing on tissue deformation could lead to new bedside monitoring and ventilatory strategies. PMID:21489320

  18. Concurrent evaluation of visual, cytological and HPV testing as screening methods for the early detection of cervical neoplasia in Mumbai, India.

    PubMed Central

    Shastri, Surendra S.; Dinshaw, Ketayun; Amin, Geetanjali; Goswami, Smriti; Patil, Sharmila; Chinoy, Roshini; Kane, S.; Kelkar, Rohini; Muwonge, Richard; Mahé, Cédric; Ajit, Dulhan; Sankaranarayanan, R.

    2005-01-01

    OBJECTIVE: Naked eye visual inspection with acetic acid (VIA), magnified VIA (VIAM), visual inspection with Lugol's iodine (VILI), cytology and human papillomavirus (HPV) testing were evaluated as screening methods for the detection of high-grade squamous intraepithelial lesions (HSIL) of the uterine cervix in a cross-sectional study in Mumbai, India. METHODS: Cytology, HPV testing, VIA, VIAM and VILI were carried out concurrently for 4039 women aged 30-65 years. All women were investigated with colposcopy and biopsies were taken from 939 women who had colposcopic abnormalities. The reference standard for final disease status was histology or negative colposcopy. The presence of HSIL was confirmed in 57 women (1.4%). The test characteristics for each method were calculated using standard formulae. RESULTS: The sensitivities of cytology, HPV testing, VIA, VIAM and VILI were 57.4%, 62.0%, 59.7%, 64.9%, and 75.4%, respectively (differences were not statistically significant). The specificities were 98.6%, 93.5%, 88.4%, 86.3%, and 84.3%, respectively. Adding a visual test to cytology or HPV testing in parallel combination resulted in a substantial increase in sensitivity, with a moderate decrease in specificity. The parallel combination of VILI and HPV testing resulted in a sensitivity of 92.0% and a specificity of 79.9%. CONCLUSION: As a single test, cytology had the best balance of sensitivity and specificity. Visual tests are promising in low-resource settings, such as India. The use of both VIA and VILI may be considered where good quality cytology or HPV testing are not feasible. The sensitivity of cytology and HPV testing increased significantly when combined with VIA or VILI. PMID:15798842

  19. Lung-derived soluble mediators are pathogenic in ventilator-induced lung injury.

    PubMed

    Jaecklin, Thomas; Engelberts, Doreen; Otulakowski, Gail; O'Brodovich, Hugh; Post, Martin; Kavanagh, Brian P

    2011-04-01

    Ventilator-induced lung injury (VILI) due to high tidal volume (V(T)) is associated with increased levels of circulating factors that may contribute to, or be markers of, injury. This study investigated if exclusively lung-derived circulating factors produced during high V(T) ventilation can cause or worsen VILI. In isolated perfused mouse lungs, recirculation of perfusate worsened injury (compliance impairment, microvascular permeability, edema) induced by high V(T). Perfusate collected from lungs ventilated with high V(T) and used to perfuse lungs ventilated with low V(T) caused similar compliance impairment and permeability and caused a dose-dependent decrease in transepithelial electrical resistance (TER) across rat distal lung epithelial monolayers. Circulating soluble factors derived from the isolated lung thus contributed to VILI and had deleterious effects on the lung epithelial barrier. These data demonstrate transferability of an injury initially caused exclusively by mechanical ventilation and provides novel evidence for the biotrauma hypothesis in VILI. Mediators of the TER decrease were heat-sensitive, transferable via Folch extraction, and (following ultrafiltration, 3 kDa) comprised both smaller and larger molecules. Although several classes of candidate mediators, including protein cytokines (e.g., tumor necrosis factor-α, interleukin-6, macrophage inflammation protein-1α) and lipids (e.g., eicosanoids, ceramides, sphingolipids), have been implicated in VILI, only prostanoids accumulated in the perfusate in a pattern consistent with a pathogenic role, yet cyclooxygenase inhibition did not protect against injury. Although no single class of factor appears solely responsible for the decrease in barrier function, the current data implicate lipid-soluble protein-bound molecules as not just markers but pathogenic mediators in VILI. PMID:21239530

  20. A2B adenosine receptor signaling attenuates acute lung injury by enhancing alveolar fluid clearance in mice.

    PubMed

    Eckle, Tobias; Grenz, Almut; Laucher, Stefanie; Eltzschig, Holger K

    2008-10-01

    Although acute lung injury contributes significantly to critical illness, resolution often occurs spontaneously via activation of incompletely understood pathways. We recently found that mechanical ventilation of mice increases the level of pulmonary adenosine, and that mice deficient for extracellular adenosine generation show increased pulmonary edema and inflammation after ventilator-induced lung injury (VILI). Here, we profiled the response to VILI in mice with genetic deletions of each of the 4 adenosine receptors (ARs) and found that deletion of the A2BAR gene was specifically associated with reduced survival time and increased pulmonary albumin leakage after injury. In WT mice, treatment with an A2BAR-selective antagonist resulted in enhanced pulmonary inflammation, edema, and attenuated gas exchange, while an A2BAR agonist attenuated VILI. In bone marrow-chimeric A2BAR mice, although the pulmonary inflammatory response involved A2BAR signaling from bone marrow-derived cells, A2BARs located on the lung tissue attenuated VILI-induced albumin leakage and pulmonary edema. Furthermore, measurement of alveolar fluid clearance (AFC) demonstrated that A2BAR signaling enhanced amiloride-sensitive fluid transport and elevation of pulmonary cAMP levels following VILI, suggesting that A2BAR agonist treatment protects by drying out the lungs. Similar enhancement of pulmonary cAMP and AFC were also observed after beta-adrenergic stimulation, a pathway known to promote AFC. Taken together, these studies reveal a role for A2BAR signaling in attenuating VILI and implicate this receptor as a potential therapeutic target during acute lung injury. PMID:18787641

  1. Non–Muscle Myosin Light Chain Kinase Isoform Is a Viable Molecular Target in Acute Inflammatory Lung Injury

    PubMed Central

    Mirzapoiazova, Tamara; Moitra, Jaideep; Moreno-Vinasco, Liliana; Sammani, Saad; Turner, Jerry R.; Chiang, Eddie T.; Evenoski, Carrie; Wang, Ting; Singleton, Patrick A.; Huang, Yong; Lussier, Yves A.; Watterson, D. Martin; Dudek, Steven M.; Garcia, Joe G. N.

    2011-01-01

    Acute lung injury (ALI) and mechanical ventilator-induced lung injury (VILI), major causes of acute respiratory failure with elevated morbidity and mortality, are characterized by significant pulmonary inflammation and alveolar/vascular barrier dysfunction. Previous studies highlighted the role of the non–muscle myosin light chain kinase isoform (nmMLCK) as an essential element of the inflammatory response, with variants in the MYLK gene that contribute to ALI susceptibility. To define nmMLCK involvement further in acute inflammatory syndromes, we used two murine models of inflammatory lung injury, induced by either an intratracheal administration of lipopolysaccharide (LPS model) or mechanical ventilation with increased tidal volumes (the VILI model). Intravenous delivery of the membrane-permeant MLC kinase peptide inhibitor, PIK, produced a dose-dependent attenuation of both LPS-induced lung inflammation and VILI (∼50% reductions in alveolar/vascular permeability and leukocyte influx). Intravenous injections of nmMLCK silencing RNA, either directly or as cargo within angiotensin-converting enzyme (ACE) antibody–conjugated liposomes (to target the pulmonary vasculature selectively), decreased nmMLCK lung expression (∼70% reduction) and significantly attenuated LPS-induced and VILI-induced lung inflammation (∼40% reduction in bronchoalveolar lavage protein). Compared with wild-type mice, nmMLCK knockout mice were significantly protected from VILI, with significant reductions in VILI-induced gene expression in biological pathways such as nrf2-mediated oxidative stress, coagulation, p53-signaling, leukocyte extravasation, and IL-6–signaling. These studies validate nmMLCK as an attractive target for ameliorating the adverse effects of dysregulated lung inflammation. PMID:20139351

  2. Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study

    PubMed Central

    2011-01-01

    Background There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis per se rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory) versus normocapnic (metabolic) acidosis in an ex vivo model of ventilator-induced lung injury (VILI). Methods Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA), metabolic acidosis (MA) and normocapnic-normoxic (Control - C) groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain), changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations. Results HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024), while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276) and 40 min (P = 0.0012) compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p < 0.001). Conclusions In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation. PMID:21486492

  3. The Extent of Ventilator-Induced Lung Injury in Mice Partly Depends on Duration of Mechanical Ventilation

    PubMed Central

    Hegeman, Maria A.; Hemmes, Sabrine N. T.; Kuipers, Maria T.; Bos, Lieuwe D. J.; Jongsma, Geartsje; Roelofs, Joris J. T. H.; van der Sluijs, Koenraad F.; Juffermans, Nicole P.; Vroom, Margreeth B.; Schultz, Marcus J.

    2013-01-01

    Background. Mechanical ventilation (MV) has the potential to initiate ventilator-induced lung injury (VILI). The pathogenesis of VILI has been primarily studied in animal models using more or less injurious ventilator settings. However, we speculate that duration of MV also influences severity and character of VILI. Methods. Sixty-four healthy C57Bl/6 mice were mechanically ventilated for 5 or 12 hours, using lower tidal volumes with positive end-expiratory pressure (PEEP) or higher tidal volumes without PEEP. Fifteen nonventilated mice served as controls. Results. All animals remained hemodynamically stable and survived MV protocols. In both MV groups, PaO2 to FiO2 ratios were lower and alveolar cell counts were higher after 12 hours of MV compared to 5 hours. Alveolar-capillary permeability was increased after 12 hours compared to 5 hours, although differences did not reach statistical significance. Lung levels of inflammatory mediators did not further increase over time. Only in mice ventilated with increased strain, lung compliance declined and wet to dry ratio increased after 12 hours of MV compared to 5 hours. Conclusions. Deleterious effects of MV are partly dependent on its duration. Even lower tidal volumes with PEEP may initiate aspects of VILI after 12 hours of MV. PMID:23691294

  4. The extent of ventilator-induced lung injury in mice partly depends on duration of mechanical ventilation.

    PubMed

    Hegeman, Maria A; Hemmes, Sabrine N T; Kuipers, Maria T; Bos, Lieuwe D J; Jongsma, Geartsje; Roelofs, Joris J T H; van der Sluijs, Koenraad F; Juffermans, Nicole P; Vroom, Margreeth B; Schultz, Marcus J

    2013-01-01

    Background. Mechanical ventilation (MV) has the potential to initiate ventilator-induced lung injury (VILI). The pathogenesis of VILI has been primarily studied in animal models using more or less injurious ventilator settings. However, we speculate that duration of MV also influences severity and character of VILI. Methods. Sixty-four healthy C57Bl/6 mice were mechanically ventilated for 5 or 12 hours, using lower tidal volumes with positive end-expiratory pressure (PEEP) or higher tidal volumes without PEEP. Fifteen nonventilated mice served as controls. Results. All animals remained hemodynamically stable and survived MV protocols. In both MV groups, PaO2 to FiO2 ratios were lower and alveolar cell counts were higher after 12 hours of MV compared to 5 hours. Alveolar-capillary permeability was increased after 12 hours compared to 5 hours, although differences did not reach statistical significance. Lung levels of inflammatory mediators did not further increase over time. Only in mice ventilated with increased strain, lung compliance declined and wet to dry ratio increased after 12 hours of MV compared to 5 hours. Conclusions. Deleterious effects of MV are partly dependent on its duration. Even lower tidal volumes with PEEP may initiate aspects of VILI after 12 hours of MV. PMID:23691294

  5. Mitochondrial-targeted DNA repair enzyme 8-oxoguanine DNA glycosylase 1 protects against ventilator-induced lung injury in intact mice

    PubMed Central

    Hashizume, Masahiro; Mouner, Marc; Chouteau, Joshua M.; Gorodnya, Olena M.; Ruchko, Mykhaylo V.; Potter, Barry J.; Wilson, Glenn L.; Gillespie, Mark N.

    2013-01-01

    This study tested the hypothesis that oxidative mitochondrial-targeted DNA (mtDNA) damage triggered ventilator-induced lung injury (VILI). Control mice and mice infused with a fusion protein targeting the DNA repair enzyme, 8-oxoguanine-DNA glycosylase 1 (OGG1) to mitochondria were mechanically ventilated with a range of peak inflation pressures (PIP) for specified durations. In minimal VILI (1 h at 40 cmH2O PIP), lung total extravascular albumin space increased 2.8-fold even though neither lung wet/dry (W/D) weight ratios nor bronchoalveolar lavage (BAL) macrophage inflammatory protein (MIP)-2 or IL-6 failed to differ from nonventilated or low PIP controls. This increase in albumin space was attenuated by OGG1. Moderately severe VILI (2 h at 40 cmH2O PIP) produced a 25-fold increase in total extravascular albumin space, a 60% increase in W/D weight ratio and marked increases in BAL MIP-2 and IL-6, accompanied by oxidative mitochondrial DNA damage, as well as decreases in the total tissue glutathione (GSH) and GSH/GSSH ratio compared with nonventilated lungs. All of these injury indices were attenuated in OGG1-treated mice. At the highest level of VILI (2 h at 50 cmH2O PIP), OGG1 failed to protect against massive lung edema and BAL cytokines or against depletion of the tissue GSH pool. Interestingly, whereas untreated mice died before completing the 2-h protocol, OGG1-treated mice lived for the duration of observation. Thus mitochondrially targeted OGG1 prevented VILI over a range of ventilation times and pressures and enhanced survival in the most severely injured group. These findings support the concept that oxidative mtDNA damage caused by high PIP triggers induction of acute lung inflammation and injury. PMID:23241530

  6. Dexamethasone Attenuates VEGF Expression and Inflammation but Not Barrier Dysfunction in a Murine Model of Ventilator–Induced Lung Injury

    PubMed Central

    Hegeman, Maria A.; Hennus, Marije P.; Cobelens, Pieter M.; Kavelaars, Annemieke; Jansen, Nicolaas J. G.; Schultz, Marcus J.; van Vught, Adrianus J.; Heijnen, Cobi J.

    2013-01-01

    Background Ventilator–induced lung injury (VILI) is characterized by vascular leakage and inflammatory responses eventually leading to pulmonary dysfunction. Vascular endothelial growth factor (VEGF) has been proposed to be involved in the pathogenesis of VILI. This study examines the inhibitory effect of dexamethasone on VEGF expression, inflammation and alveolar–capillary barrier dysfunction in an established murine model of VILI. Methods Healthy male C57Bl/6 mice were anesthetized, tracheotomized and mechanically ventilated for 5 hours with an inspiratory pressure of 10 cmH2O (“lower” tidal volumes of ∼7.5 ml/kg; LVT) or 18 cmH2O (“higher” tidal volumes of ∼15 ml/kg; HVT). Dexamethasone was intravenously administered at the initiation of HVT–ventilation. Non–ventilated mice served as controls. Study endpoints included VEGF and inflammatory mediator expression in lung tissue, neutrophil and protein levels in bronchoalveolar lavage fluid, PaO2 to FiO2 ratios and lung wet to dry ratios. Results Particularly HVT–ventilation led to alveolar–capillary barrier dysfunction as reflected by reduced PaO2 to FiO2 ratios, elevated alveolar protein levels and increased lung wet to dry ratios. Moreover, VILI was associated with enhanced VEGF production, inflammatory mediator expression and neutrophil infiltration. Dexamethasone treatment inhibited VEGF and pro–inflammatory response in lungs of HVT–ventilated mice, without improving alveolar–capillary permeability, gas exchange and pulmonary edema formation. Conclusions Dexamethasone treatment completely abolishes ventilator–induced VEGF expression and inflammation. However, dexamethasone does not protect against alveolar–capillary barrier dysfunction in an established murine model of VILI. PMID:23451215

  7. Ventilator-induced lung injury is reduced in transgenic mice that overexpress endothelial nitric oxide synthase.

    PubMed

    Takenaka, Kaori; Nishimura, Yoshihiro; Nishiuma, Teruaki; Sakashita, Akihiro; Yamashita, Tomoya; Kobayashi, Kazuyuki; Satouchi, Miyako; Ishida, Tatsuro; Kawashima, Seinosuke; Yokoyama, Mitsuhiro

    2006-06-01

    Although mechanical ventilation (MV) is an important supportive strategy for patients with acute respiratory distress syndrome, MV itself can cause a type of acute lung damage termed ventilator-induced lung injury (VILI). Because nitric oxide (NO) has been reported to play roles in the pathogenesis of acute lung injury, the present study explores the effects on VILI of NO derived from chronically overexpressed endothelial nitric oxide synthase (eNOS). Anesthetized eNOS-transgenic (Tg) and wild-type (WT) C57BL/6 mice were ventilated at high or low tidal volume (Vt; 20 or 7 ml/kg, respectively) for 4 h. After MV, lung damage, including neutrophil infiltration, water leakage, and cytokine concentration in bronchoalveolar lavage fluid (BALF) and plasma, was evaluated. Some mice were given N(omega)-nitro-L-arginine methyl ester (L-NAME), a potent NOS inhibitor, via drinking water (1 mg/ml) for 1 wk before MV. Histological analysis revealed that high Vt ventilation caused severe VILI, whereas low Vt ventilation caused minimal VILI. Under high Vt conditions, neutrophil infiltration and lung water content were significantly attenuated in eNOS-Tg mice compared with WT animals. The concentrations of macrophage inflammatory protein-2 in BALF and plasma, as well as plasma tumor necrosis factor-alpha and monocyte chemoattractant protein-1, also were decreased in eNOS-Tg mice. L-NAME abrogated the beneficial effect of eNOS overexpression. In conclusion, chronic eNOS overexpression may protect the lung from VILI by inhibiting the production of inflammatory chemokines and cytokines that are associated with neutrophil infiltration into the air space. PMID:16399791

  8. Nonextensive critical effects in the NJL model

    NASA Astrophysics Data System (ADS)

    Rozynek, Jacek

    2015-05-01

    It is shown how nonextensive Nambu-Jona-Lasinio (NJL) calculations in the critical region in the vicinity of phase transition to quark matter allow to determine a nonextensive parameter q from a specific heat capacity Cq.

  9. Hepatitis C - children

    MedlinePlus

    ... virus (HCV). Other common hepatitis virus infections include hepatitis A and hepatitis B . ... Elisofon SA, Jonas MMF. Viral hepatitis in children. In: Boyer TD, Manns MP, Sanyal AJ, eds. Zakim & Boyer's Hepatology: A Textbook of Liver Disease. 6th ed. ...

  10. Induced Pluripotent Stem Cell Therapy Ameliorates Hyperoxia-Augmented Ventilator-Induced Lung Injury through Suppressing the Src Pathway

    PubMed Central

    Liu, Yung-Yang; Fu, Jui-Ying; Kao, Kuo-Chin; Huang, Chung-Chi; Chien, Yueh; Liao, Yi-Wen; Chiou, Shih-Hwa

    2014-01-01

    Background High tidal volume (VT) mechanical ventilation (MV) can induce the recruitment of neutrophils, release of inflammatory cytokines and free radicals, and disruption of alveolar epithelial and endothelial barriers. It is proposed to be the triggering factor that initiates ventilator-induced lung injury (VILI) and concomitant hyperoxia further aggravates the progression of VILI. The Src protein tyrosine kinase (PTK) family is one of the most critical families to intracellular signal transduction related to acute inflammatory responses. The anti-inflammatory abilities of induced pluripotent stem cells (iPSCs) have been shown to improve acute lung injuries (ALIs); however, the mechanisms regulating the interactions between MV, hyperoxia, and iPSCs have not been fully elucidated. In this study, we hypothesize that Src PTK plays a critical role in the regulation of oxidants and inflammation-induced VILI during hyperoxia. iPSC therapy can ameliorate acute hyperoxic VILI by suppressing the Src pathway. Methods Male C57BL/6 mice, either wild-type or Src-deficient, aged between 2 and 3 months were exposed to high VT (30 mL/kg) ventilation with or without hyperoxia for 1 to 4 h after the administration of Oct4/Sox2/Parp1 iPSCs at a dose of 5×107 cells/kg of mouse. Nonventilated mice were used for the control groups. Results High VT ventilation during hyperoxia further aggravated VILI, as demonstrated by the increases in microvascular permeability, neutrophil infiltration, macrophage inflammatory protein-2 (MIP-2) and plasminogen activator inhibitor-1 (PAI-1) production, Src activation, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, and malaldehyde (MDA) level. Administering iPSCs attenuated ALI induced by MV during hyperoxia, which benefited from the suppression of Src activation, oxidative stress, acute inflammation, and apoptosis, as indicated by the Src-deficient mice. Conclusion The data suggest that iPSC-based therapy is capable of

  11. The effect of low level laser therapy on ventilator-induced lung injury in mice (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Szabari, Margit V.; Miller, Alyssa J.; Hariri, Lida P.; Hamblin, Michael R.; Musch, Guido; Stroh, Helene; Suter, Melissa J.

    2016-03-01

    Although mechanical ventilation (MV) is necessary to support gas exchange in critically ill patients, it can contribute to the development of lung injury and multiple organ dysfunction. It is known that high tidal volume (Vt) MV can cause ventilator-induced lung injury (VILI) in healthy lungs and increase the mortality of patients with Acute Respiratory Distress Syndrome. Low level laser therapy (LLLT) has demonstrated to have anti-inflammatory effects. We investigated whether LLLT could alleviate inflammation from injurious MV in mice. Adult mice were assigned to 2 groups: VILI+LLLT group (3 h of injurious MV: Vt=25-30 ml/kg, respiratory rate (RR)=50/min, positive end-expiratory pressure (PEEP)=0 cmH20, followed by 3 h of protective MV: Vt=9 ml/kg, RR=140/min, PEEP=2 cmH20) and VILI+no LLLT group. LLLT was applied during the first 30 min of the MV (810 nm LED system, 5 J/cm2, 1 cm above the chest). Respiratory impedance was measured in vivo with forced oscillation technique and lung mechanics were calculated by fitting the constant phase model. At the end of the MV, bronchoalveolar lavage (BAL) was performed and inflammatory cells counted. Lungs were removed en-bloc and fixed for histological evaluation. We hypothesize that LLLT can reduce lung injury and inflammation from VILI. This therapy could be translated into clinical practice, where it can potentially improve outcomes in patients requiring mechanical ventilation in the operating room or in the intensive care units.

  12. ATF3 Protects Pulmonary Resident Cells from Acute and Ventilator-Induced Lung Injury by Preventing Nrf2 Degradation

    PubMed Central

    Shan, Yuexin; Akram, Ali; Amatullah, Hajera; Zhou, Dun Yuan; Gali, Patricia L.; Maron-Gutierrez, Tatiana; González-López, Adrian; Zhou, Louis; Rocco, Patricia R.M.; Hwang, David; Albaiceta, Guillermo M.; Haitsma, Jack J.

    2015-01-01

    Abstract Aims: Ventilator-induced lung injury (VILI) contributes to mortality in patients with acute respiratory distress syndrome, the most severe form of acute lung injury (ALI). Absence of activating transcription factor 3 (ATF3) confers susceptibility to ALI/VILI. To identify cell-specific ATF3-dependent mechanisms of susceptibility to ALI/VILI, we generated ATF3 chimera by adoptive bone marrow (BM) transfer and randomized to inhaled saline or lipopolysacharide (LPS) in the presence of mechanical ventilation (MV). Adenovirus vectors to silence or overexpress ATF3 were used in primary human bronchial epithelial cells and murine BM-derived macrophages from wild-type or ATF3-deficient mice. Results: Absence of ATF3 in myeloid-derived cells caused increased pulmonary cellular infiltration. In contrast, absence of ATF3 in parenchymal cells resulted in loss of alveolar-capillary membrane integrity and increased exudative edema. ATF3-deficient macrophages were unable to limit the expression of pro-inflammatory mediators. Knockdown of ATF3 in resident cells resulted in decreased junctional protein expression and increased paracellular leak. ATF3 overexpression abrogated LPS induced membrane permeability. Despite release of ATF3-dependent Nrf2 transcriptional inhibition, mice that lacked ATF3 expression in resident cells had increased Nrf2 protein degradation. Innovation: In our model, in the absence of ATF3 in parenchymal cells increased Nrf2 degradation is the result of increased Keap-1 expression and loss of DJ-1 (Parkinson disease [autosomal recessive, early onset] 7), previously not known to play a role in lung injury. Conclusion: Results suggest that ATF3 confers protection to lung injury by preventing inflammatory cell recruitment and barrier disruption in a cell-specific manner, opening novel opportunities for cell specific therapy for ALI/VILI. Antioxid. Redox Signal. 22, 651–668. PMID:25401197

  13. Hydrogen inhalation reduced epithelial apoptosis in ventilator-induced lung injury via a mechanism involving nuclear factor-kappa B activation

    SciTech Connect

    Huang, Chien-Sheng; Kawamura, Tomohiro; Peng, Ximei; Tochigi, Naobumi; Shigemura, Norihisa; Billiar, Timothy R.; Nakao, Atsunori; Toyoda, Yoshiya

    2011-05-06

    Highlights: {yields} Hydrogen is a regulatory molecule with antiinflammatory and antiapoptotic protective effects. {yields} There is very limited information on the pathways regulated in vivo by the hydrogen. {yields} Antiapoptotic abilities of hydrogen were explained by upregulation of the antiapoptotic gene. {yields} NF{kappa}B activation during hydrogen treatment was correlated with elevated antiapoptotic protein. {yields} NF{kappa}B activation associated with increase Bcl-2 may contribute to cytoprotection of hydrogen. -- Abstract: We recently demonstrated the inhalation of hydrogen gas, a novel medical therapeutic gas, ameliorates ventilator-induced lung injury (VILI); however, the molecular mechanisms by which hydrogen ameliorates VILI remain unclear. Therefore, we investigated whether inhaled hydrogen gas modulates the nuclear factor-kappa B (NF{kappa}B) signaling pathway. VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg or 10 ml/kg without positive end-expiratory pressure). The ventilator delivered either 2% nitrogen or 2% hydrogen in balanced air. NF{kappa}B activation, as indicated by NF{kappa}B DNA binding, was detected by electrophoretic mobility shift assays and enzyme-linked immunosorbent assay. Hydrogen gas inhalation increased NF{kappa}B DNA binding after 1 h of ventilation and decreased NF{kappa}B DNA binding after 2 h of ventilation, as compared with controls. The early activation of NF{kappa}B during hydrogen treatment was correlated with elevated levels of the antiapoptotic protein Bcl-2 and decreased levels of Bax. Hydrogen inhalation increased oxygen tension, decreased lung edema, and decreased the expression of proinflammatory mediators. Chemical inhibition of early NF{kappa}B activation using SN50 reversed these protective effects. NF{kappa}B activation and an associated increase in the expression of Bcl-2 may contribute, in part, to the

  14. Exposure to mechanical ventilation promotes tolerance to ventilator-induced lung injury by Ccl3 downregulation.

    PubMed

    Blázquez-Prieto, Jorge; López-Alonso, Inés; Amado-Rodríguez, Laura; Batalla-Solís, Estefanía; González-López, Adrián; Albaiceta, Guillermo M

    2015-10-15

    Inflammation plays a key role in the development of ventilator-induced lung injury (VILI). Preconditioning with a previous exposure can damp the subsequent inflammatory response. Our objectives were to demonstrate that tolerance to VILI can be induced by previous low-pressure ventilation, and to identify the molecular mechanisms responsible for this phenomenon. Intact 8- to 12-wk-old male CD1 mice were preconditioned with 90 min of noninjurious ventilation [peak pressure 17 cmH2O, positive end-expiratory pressure (PEEP) 2 cmH2O] and extubated. Seven days later, preconditioned mice and intact controls were submitted to injurious ventilation (peak pressure 20 cmH2O, PEEP 0 cmH2O) for 2 h to induce VILI. Preconditioned mice showed lower histological lung injury scores, bronchoalveolar lavage albumin content, and lung neutrophilic infiltration after injurious ventilation, with no differences in Il6 or Il10 expression. Microarray analyses revealed a downregulation of Calcb, Hspa1b, and Ccl3, three genes related to tolerance phenomena, in preconditioned animals. Among the previously identified genes, only Ccl3, which encodes the macrophage inflammatory protein 1 alpha (MIP-1α), showed significant differences between intact and preconditioned mice after high-pressure ventilation. In separate, nonconditioned animals, treatment with BX471, a specific blocker of CCR1 (the main receptor for MIP-1α), decreased lung damage and neutrophilic infiltration caused by high-pressure ventilation. We conclude that previous exposure to noninjurious ventilation induces a state of tolerance to VILI. Downregulation of the chemokine gene Ccl3 could be the mechanism responsible for this effect. PMID:26472813

  15. Kinetic profiling of in vivo lung cellular inflammatory responses to mechanical ventilation

    PubMed Central

    Woods, Samantha J.; Waite, Alicia A. C.; O'Dea, Kieran P.; Halford, Paul; Takata, Masao

    2015-01-01

    Mechanical ventilation, through overdistension of the lung, induces substantial inflammation that is thought to increase mortality among critically ill patients. The mechanotransduction processes involved in converting lung distension into inflammation during this ventilator-induced lung injury (VILI) remain unclear, although many cell types have been shown to be involved in its pathogenesis. This study aimed to identify the profile of in vivo lung cellular activation that occurs during the initiation of VILI. This was achieved using a flow cytometry-based method to quantify the phosphorylation of several markers (p38, ERK1/2, MAPK-activated protein kinase 2, and NF-κB) of inflammatory pathway activation within individual cell types. Anesthetized C57BL/6 mice were ventilated with low (7 ml/kg), intermediate (30 ml/kg), or high (40 ml/kg) tidal volumes for 1, 5, or 15 min followed by immediate fixing and processing of the lungs. Surprisingly, the pulmonary endothelium was the cell type most responsive to in vivo high-tidal-volume ventilation, demonstrating activation within just 1 min, followed by the alveolar epithelium. Alveolar macrophages were the slowest to respond, although they still demonstrated activation within 5 min. This order of activation was specific to VILI, since intratracheal lipopolysaccharide induced a very different pattern. These results suggest that alveolar macrophages may become activated via a secondary mechanism that occurs subsequent to activation of the parenchyma and that the lung cellular activation mechanism may be different between VILI and lipopolysaccharide. Our data also demonstrate that even very short periods of high stretch can promote inflammatory activation, and, importantly, this injury may be immediately manifested within the pulmonary vasculature. PMID:25770178

  16. Intermedin Stabilized Endothelial Barrier Function and Attenuated Ventilator-induced Lung Injury in Mice

    PubMed Central

    Müller-Redetzky, Holger Christian; Kummer, Wolfgang; Pfeil, Uwe; Hellwig, Katharina; Will, Daniel; Paddenberg, Renate; Tabeling, Christoph; Hippenstiel, Stefan; Suttorp, Norbert; Witzenrath, Martin

    2012-01-01

    Background Even protective ventilation may aggravate or induce lung failure, particularly in preinjured lungs. Thus, new adjuvant pharmacologic strategies are needed to minimize ventilator-induced lung injury (VILI). Intermedin/Adrenomedullin-2 (IMD) stabilized pulmonary endothelial barrier function in vitro. We hypothesized that IMD may attenuate VILI-associated lung permeability in vivo. Methodology/Principal Findings Human pulmonary microvascular endothelial cell (HPMVEC) monolayers were incubated with IMD, and transcellular electrical resistance was measured to quantify endothelial barrier function. Expression and localization of endogenous pulmonary IMD, and its receptor complexes composed of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs) 1–3 were analyzed by qRT-PCR and immunofluorescence in non ventilated mouse lungs and in lungs ventilated for 6 h. In untreated and IMD treated mice, lung permeability, pulmonary leukocyte recruitment and cytokine levels were assessed after mechanical ventilation. Further, the impact of IMD on pulmonary vasoconstriction was investigated in precision cut lung slices (PCLS) and in isolated perfused and ventilated mouse lungs. IMD stabilized endothelial barrier function in HPMVECs. Mechanical ventilation reduced the expression of RAMP3, but not of IMD, CRLR, and RAMP1 and 2. Mechanical ventilation induced lung hyperpermeability, which was ameliorated by IMD treatment. Oxygenation was not improved by IMD, which may be attributed to impaired hypoxic vasoconstriction due to IMD treatment. IMD had minor impact on pulmonary leukocyte recruitment and did not reduce cytokine levels in VILI. Conclusions/Significance IMD may possibly provide a new approach to attenuate VILI. PMID:22563471

  17. Unique Toll-Like Receptor 4 Activation by NAMPT/PBEF Induces NFκB Signaling and Inflammatory Lung Injury

    PubMed Central

    Camp, Sara M.; Ceco, Ermelinda; Evenoski, Carrie L.; Danilov, Sergei M.; Zhou, Tong; Chiang, Eddie T.; Moreno-Vinasco, Liliana; Mapes, Brandon; Zhao, Jieling; Gursoy, Gamze; Brown, Mary E.; Adyshev, Djanybek M.; Siddiqui, Shahid S.; Quijada, Hector; Sammani, Saad; Letsiou, Eleftheria; Saadat, Laleh; Yousef, Mohammed; Wang, Ting; Liang, Jie; Garcia, Joe G. N.

    2015-01-01

    Ventilator-induced inflammatory lung injury (VILI) is mechanistically linked to increased NAMPT transcription and circulating levels of nicotinamide phosphoribosyl-transferase (NAMPT/PBEF). Although VILI severity is attenuated by reduced NAMPT/PBEF bioavailability, the precise contribution of NAMPT/PBEF and excessive mechanical stress to VILI pathobiology is unknown. We now report that NAMPT/PBEF induces lung NFκB transcriptional activities and inflammatory injury via direct ligation of Toll–like receptor 4 (TLR4). Computational analysis demonstrated that NAMPT/PBEF and MD-2, a TLR4-binding protein essential for LPS-induced TLR4 activation, share ~30% sequence identity and exhibit striking structural similarity in loop regions critical for MD-2-TLR4 binding. Unlike MD-2, whose TLR4 binding alone is insufficient to initiate TLR4 signaling, NAMPT/PBEF alone produces robust TLR4 activation, likely via a protruding region of NAMPT/PBEF (S402-N412) with structural similarity to LPS. The identification of this unique mode of TLR4 activation by NAMPT/PBEF advances the understanding of innate immunity responses as well as the untoward events associated with mechanical stress-induced lung inflammation. PMID:26272519

  18. Role of Integrin β4 in Lung Endothelial Cell Inflammatory Responses to Mechanical Stress.

    PubMed

    Chen, Weiguo; Epshtein, Yulia; Ni, Xiuquin; Dull, Randal O; Cress, Anne E; Garcia, Joe G N; Jacobson, Jeffrey R

    2015-01-01

    Simvastatin, an HMG-CoA reductase inhibitor, has lung vascular-protective effects that are associated with decreased agonist-induced integrin β4 (ITGB4) tyrosine phosphorylation. Accordingly, we hypothesized that endothelial cell (EC) protection by simvastatin is dependent on these effects and sought to further characterize the functional role of ITGB4 as a mediator of EC protection in the setting of excessive mechanical stretch at levels relevant to ventilator-induced lung injury (VILI). Initially, early ITGB4 tyrosine phosphorylation was confirmed in human pulmonary artery EC subjected to excessive cyclic stretch (18% CS). EC overexpression of mutant ITGB4 with specific tyrosines mutated to phenylalanine (Y1440, Y1526 Y1640, or Y1422) resulted in significantly attenuated CS-induced cytokine expression (IL6, IL-8, MCP-1, and RANTES). In addition, EC overexpression of ITGB4 constructs with specific structural deletions also resulted in significantly attenuated CS-induced inflammatory cytokine expression compared to overexpression of wildtype ITGB4. Finally, mice expressing a mutant ITGB4 lacking a cytoplasmic signaling domain were found to have attenuated lung injury after VILI-challenge (VT = 40 ml/kg, 4 h). Our results provide mechanistic insights into the anti-inflammatory properties of statins and may ultimately lead to novel strategies targeted at ITGB4 signaling to treat VILI. PMID:26572585

  19. Quantifying the roles of tidal volume and PEEP in the pathogenesis of ventilator-induced lung injury.

    PubMed

    Seah, Adrian S; Grant, Kara A; Aliyeva, Minara; Allen, Gilman B; Bates, Jason H T

    2011-05-01

    Management of patients with acute lung injury (ALI) rests on achieving a balance between the gas exchanging benefits of mechanical ventilation and the exacerbation of tissue damage in the form of ventilator-induced lung injury (VILI). Optimizing this balance requires an injury cost function relating injury progression to the measurable pressures, flows, and volumes delivered during mechanical ventilation. With this in mind, we mechanically ventilated naive, anesthetized, paralyzed mice for 4 h using either a low or high tidal volume (Vt) with either moderate or zero positive end-expiratory pressure (PEEP). The derecruitability of the lung was assessed every 15 min in terms of the degree of increase in lung elastance occurring over 3 min following a recruitment maneuver. Mice could be safely ventilated for 4 h with either a high Vt or zero PEEP, but when both conditions were applied simultaneously the lung became increasingly unstable, demonstrating worsening injury. We were able to mimic these data using a computational model of dynamic recruitment and derecruitment that simulates the effects of progressively increasing surface tension at the air-liquid interface, suggesting that the VILI in our animal model progressed via a vicious cycle of alveolar leak, degradation of surfactant function, and increasing tissue stress. We thus propose that the task of ventilating the injured lung is usefully understood in terms of the Vt-PEEP plane. Within this plane, non-injurious combinations of Vt and PEEP lie within a "safe region", the boundaries of which shrink as VILI develops. PMID:21203845

  20. Cervical Cancer Screening Program by Visual Inspection: Acceptability and Feasibility in Health Insurance Companies

    PubMed Central

    Horo, Apollinaire G.; Didi-Kouko Coulibaly, Judith; Koffi, Abdoul; Tchounga, Boris; Seni, Konan; Aka, Kacou Edèle; Kone, Mamourou

    2015-01-01

    Objective. To assess willingness to participate and diagnostic accuracy of visual inspection for early detection of cervical neoplasia among women in a health insurance company. Patients and Method. Cervical cancer screening was systematically proposed to 800 women after consecutive information and awareness sessions. The screening method was visual inspection with acetic acid (VIA) or Lugol's iodine (VILI). Results. Among the 800 identified women, 640 (82%) have accepted the screening, their mean age was 39 years, and 12.0% of them were involved in a polygamist couple. 28.2% of women had prior cervical screening. VIA has been detected positive in 5.9% of women versus 8.6% for VILI. The sensitivity was 72.9% and specificity was 95.2% for VIA versus 71.2% and 97.3% for VILI respectively. The histological examination highlighted a nonspecific chronic cervicitis in 4.6%, CIN1 lesions in 5.91%, and CIN2/3 in 1.2% of the cases. Conclusion. Cervical cancer screening by visual inspection showed appropriate diagnostic accuracy when used to detect early cervical lesions. It is a simple and easy to perform method that could be introduced progressively in the health insurance policy while waiting for a national screening program. PMID:26167178

  1. Imatinib attenuates inflammation and vascular leak in a clinically relevant two-hit model of acute lung injury.

    PubMed

    Rizzo, Alicia N; Sammani, Saad; Esquinca, Adilene E; Jacobson, Jeffrey R; Garcia, Joe G N; Letsiou, Eleftheria; Dudek, Steven M

    2015-12-01

    Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), an illness characterized by life-threatening vascular leak, is a significant cause of morbidity and mortality in critically ill patients. Recent preclinical studies and clinical observations have suggested a potential role for the chemotherapeutic agent imatinib in restoring vascular integrity. Our prior work demonstrates differential effects of imatinib in mouse models of ALI, namely attenuation of LPS-induced lung injury but exacerbation of ventilator-induced lung injury (VILI). Because of the critical role of mechanical ventilation in the care of patients with ARDS, in the present study we pursued an assessment of the effectiveness of imatinib in a "two-hit" model of ALI caused by combined LPS and VILI. Imatinib significantly decreased bronchoalveolar lavage protein, total cells, neutrophils, and TNF-α levels in mice exposed to LPS plus VILI, indicating that it attenuates ALI in this clinically relevant model. In subsequent experiments focusing on its protective role in LPS-induced lung injury, imatinib attenuated ALI when given 4 h after LPS, suggesting potential therapeutic effectiveness when given after the onset of injury. Mechanistic studies in mouse lung tissue and human lung endothelial cells revealed that imatinib inhibits LPS-induced NF-κB expression and activation. Overall, these results further characterize the therapeutic potential of imatinib against inflammatory vascular leak. PMID:26432864

  2. Impact of mechanical ventilation on the pathophysiology of progressive acute lung injury.

    PubMed

    Nieman, Gary F; Gatto, Louis A; Habashi, Nader M

    2015-12-01

    The earliest description of what is now known as the acute respiratory distress syndrome (ARDS) was a highly lethal double pneumonia. Ashbaugh and colleagues (Ashbaugh DG, Bigelow DB, Petty TL, Levine BE Lancet 2: 319-323, 1967) correctly identified the disease as ARDS in 1967. Their initial study showing the positive effect of mechanical ventilation with positive end-expiratory pressure (PEEP) on ARDS mortality was dampened when it was discovered that improperly used mechanical ventilation can cause a secondary ventilator-induced lung injury (VILI), thereby greatly exacerbating ARDS mortality. This Synthesis Report will review the pathophysiology of ARDS and VILI from a mechanical stress-strain perspective. Although inflammation is also an important component of VILI pathology, it is secondary to the mechanical damage caused by excessive strain. The mechanical breath will be deconstructed to show that multiple parameters that comprise the breath-airway pressure, flows, volumes, and the duration during which they are applied to each breath-are critical to lung injury and protection. Specifically, the mechanisms by which a properly set mechanical breath can reduce the development of excessive fluid flux and pulmonary edema, which are a hallmark of ARDS pathology, are reviewed. Using our knowledge of how multiple parameters in the mechanical breath affect lung physiology, the optimal combination of pressures, volumes, flows, and durations that should offer maximum lung protection are postulated. PMID:26472873

  3. Ventilator-associated lung injury.

    PubMed

    Kuchnicka, Katarzyna; Maciejewski, Dariusz

    2013-01-01

    Mechanical ventilation of disease-affected lungs, as well as being an inadequate mode of ventilation for initially healthy lungs, can cause significant changes in their structure and function. In order to differentiate these processes, two terms are used: ventilator-associated lung injury (VALI) and ventilator-induced lung injury (VILI). In both cases, lung injury primarily results from differences in transpulmonary pressure - a consequence of an imbalance between lung stress and strain. This paper focuses on changes in lung structure and function due to this imbalance. Moreover, in this context, barotrauma, volutrauma and atelectrauma are interpreted, and the importance of signal transduction as a process inducing local and systemic inflammatory responses (biotrauma), is determined. None of the assessed methods of reducing VALI and VILI has been found to be entirely satisfactory, yet studies evaluating oscillatory ventilation, liquid ventilation, early ECMO, super-protective ventilation or noisy ventilation and administration of certain drugs are under way. Low tidal volume ventilation and adequately adjusted PEEP appear to be the best preventive measures of mechanical ventilation in any setting, including the operating theatre. Furthermore, this paper highlights the advances in VILI/VALI prevention resulting from better understanding of pathophysiological phenomena. PMID:24092514

  4. Unique Toll-Like Receptor 4 Activation by NAMPT/PBEF Induces NFκB Signaling and Inflammatory Lung Injury.

    PubMed

    Camp, Sara M; Ceco, Ermelinda; Evenoski, Carrie L; Danilov, Sergei M; Zhou, Tong; Chiang, Eddie T; Moreno-Vinasco, Liliana; Mapes, Brandon; Zhao, Jieling; Gursoy, Gamze; Brown, Mary E; Adyshev, Djanybek M; Siddiqui, Shahid S; Quijada, Hector; Sammani, Saad; Letsiou, Eleftheria; Saadat, Laleh; Yousef, Mohammed; Wang, Ting; Liang, Jie; Garcia, Joe G N

    2015-01-01

    Ventilator-induced inflammatory lung injury (VILI) is mechanistically linked to increased NAMPT transcription and circulating levels of nicotinamide phosphoribosyl-transferase (NAMPT/PBEF). Although VILI severity is attenuated by reduced NAMPT/PBEF bioavailability, the precise contribution of NAMPT/PBEF and excessive mechanical stress to VILI pathobiology is unknown. We now report that NAMPT/PBEF induces lung NFκB transcriptional activities and inflammatory injury via direct ligation of Toll-like receptor 4 (TLR4). Computational analysis demonstrated that NAMPT/PBEF and MD-2, a TLR4-binding protein essential for LPS-induced TLR4 activation, share ~30% sequence identity and exhibit striking structural similarity in loop regions critical for MD-2-TLR4 binding. Unlike MD-2, whose TLR4 binding alone is insufficient to initiate TLR4 signaling, NAMPT/PBEF alone produces robust TLR4 activation, likely via a protruding region of NAMPT/PBEF (S402-N412) with structural similarity to LPS. The identification of this unique mode of TLR4 activation by NAMPT/PBEF advances the understanding of innate immunity responses as well as the untoward events associated with mechanical stress-induced lung inflammation. PMID:26272519

  5. Membrane translocation of IL-33 receptor in ventilator induced lung injury.

    PubMed

    Yang, Shih-Hsing; Lin, Jau-Chen; Wu, Shu-Yu; Huang, Kun-Lun; Jung, Fang; Ma, Ming-Chieh; Wang Hsu, Guoo-Shyng; Jow, Guey-Mei

    2015-01-01

    Ventilator-induced lung injury is associated with inflammatory mechanism and causes high mortality. The objective of this study was to discover the role of IL-33 and its ST2 receptor in acute lung injury induced by mechanical ventilator (ventilator-induced lung injury; VILI). Male Wistar rats were intubated after tracheostomy and received ventilation at 10 cm H2O of inspiratory pressure (PC10) by a G5 ventilator for 4 hours. The hemodynamic and respiratory parameters were collected and analyzed. The morphological changes of lung injury were also assessed by histological H&E stain. The dynamic changes of lung injury markers such as TNF-α and IL-1β were measured in serum, bronchoalveolar lavage fluid (BALF), and lung tissue homogenization by ELISA assay. During VILI, the IL-33 profile change was detected in BALF, peripheral serum, and lung tissue by ELISA analysis. The Il-33 and ST2 expression were analyzed by immunohistochemistry staining and western blot analysis. The consequence of VILI by H&E stain showed inducing lung congestion and increasing the expression of pro-inflammatory cytokines such as TNF-α and IL-1β in the lung tissue homogenization, serum, and BALF, respectively. In addition, rats with VILI also exhibited high expression of IL-33 in lung tissues. Interestingly, the data showed that ST2L (membrane form) was highly accumulated in the membrane fraction of lung tissue in the PC10 group, but the ST2L in cytosol was dramatically decreased in the PC10 group. Conversely, the sST2 (soluble form) was slightly decreased both in the membrane and cytosol fractions in the PC10 group compared to the control group. In conclusion, these results demonstrated that ST2L translocation from the cytosol to the cell membranes of lung tissue and the down-expression of sST2 in both fractions can function as new biomarkers of VILI. Moreover, IL-33/ST2 signaling activated by mechanically responsive lung injury may potentially serve as a new therapy target. PMID:25815839

  6. Gluon condensate in a pion superfluid beyond the mean-field approximation

    SciTech Connect

    Jiang Yin; Zhuang Pengfei

    2011-03-15

    We study gluon condensate in a pion superfluid by calculating the equation of state of the system in the Nambu-Jona-Lasinio model. While in mean-field approximation the growing pion condensate leads to an increasing gluon condensate, meson fluctuations reduce the gluon condensate, and the broken scalar symmetry can be smoothly restored at finite isospin density.

  7. Salk therapy begins.

    PubMed

    1996-01-01

    A clinical trial to test an immune therapy developed by polio pioneer Jonas Salk has begun enrollment of 3,000 participants, who will receive Remune shots every 12 weeks for 3 years to see if disease progression is slowed. The manufacturer is Immune Response, and the study is being conducted by the University of California at San Francisco. PMID:11363429

  8. Toward a Communication Theory Focused on Humankind's Future.

    ERIC Educational Resources Information Center

    Ternent, William A.; Ternent, Janet A.

    This speech presents a model of human communication which integrates the existential philosophy of Martin Buber with the communication views of Jonas Salk. In his book, "The Survival of the Wisest," Salk characterizes an "Epoch A" to describe the values and behaviors of the past and an "Epoch B" to describe the necessary values and behaviors for…

  9. 76 FR 9579 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ... customer satisfaction not only with the Beneficiary Contact Center's (BCC's) handling of issues via... Annual Responses: 448; Total Annual Hours: 7,840. (For policy questions regarding this collection contact.... (For policy questions regarding this collection contact Jonas Eberly at 410-786-6232. For all...

  10. Proceedings of the 1990 Annual Meeting of the Association for Education in Journalism and Mass Communication (73rd, Minneapolis, Minnesota, August 1-4, 1990). Part VI: Foreign and International Media Studies.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The foreign and international media studies section of the proceedings includes the following 11 papers: "The Contemporary Pacific Islands Press" (Suzanna Layton); "Cultural Domination and Sovereignty: The Development of European TV Quotas, 1981-89" (Ulf Jonas Bjork); "A Content Analysis of TV News in Saudi Arabia and Oman" (Abdulrahman I.…

  11. Three Misunderstandings of Plato's Theory of Moral Education

    ERIC Educational Resources Information Center

    Jonas, Mark E.

    2016-01-01

    In this essay, Mark Jonas argues that there are three broadly held misconceptions of Plato's philosophy that work against his relevance for contemporary moral education. The first is that he is an intellectualist who is concerned only with the cognitive aspect of moral development and does not sufficiently emphasize the affective and conative…

  12. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (75th, Montreal, Quebec, Canada, August 5-8, 1992). Part II: Journalism History, Section B.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    Section B of the Journalism History section of the proceedings contains the following nine papers: "Weep into Silence/Cries of Rage: Bitter Divisions in Hawaii's Japanese Press" (Tom Brislin); "Viewing the Newspaper as International: The First International Organization of Journalists Debates News Copyright 1894-1898" (Ulf Jonas Bjork); "The…

  13. Aspects of the strongly interacting matter phase diagram within non-local quark models

    SciTech Connect

    Pagura, V.; Dumm, D. G.; Scoccola, N. N.

    2013-03-25

    We study a nonlocal extension of the so-called Polyakov Nambu-Jona-Lasinio model at finite temperature and chemical potential, considering the impact of the presence of dynamical quarks on the scale parameter appearing in the Polyakov potential. Both real and imaginary chemical potentials are considered. The effect of varying the current quark mass is also investigated.

  14. One Adolescent's Construction of Native Identity in School: "Speaking with Dance and Not in Words and Writing"

    ERIC Educational Resources Information Center

    Wilson, Amy Alexandra; Boatright, Michael D.

    2011-01-01

    This case study describes how one eighth-grade student, Jon, asserted Native identities in texts as he attended a middle school in the western United States. Jon--a self-described Native American, Navajo, and Paiute with verified Native ancestry--sought to share what he called his Native culture with others in his school wherein he was the only…

  15. Ben Jonson: A Collection of Critical Essays. Twentieth Century Views Series.

    ERIC Educational Resources Information Center

    Barish, Jonas A., Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection includes essays by Jonas A. Barish, T. S. Eliot, L. C. Knights, Harry Levin, Edmund Wilson, Arthur Sale, C. H. Herford, Paul Goodman, Edward B. Partridge, Ray L. Heffner, Jr., Joseph Allen Bryant, Jr., and Dolora Cunningham--all dealing…

  16. How Can Video Supported Reflection Enhance Teachers' Professional Development?

    ERIC Educational Resources Information Center

    McCullagh, John F.

    2012-01-01

    This paper responds to Eva Lundqvist, Jonas Almqvist and Leif Ostman's account of how the manner of teaching can strongly influence pupil learning by recommending video supported reflection as a means by which teachers can transform the nature of their practice. Given the complex nature of the many conditions which influence and control teachers'…

  17. American Journalism Historians Association Annual Convention (London, Ontario, Canada, October 3-5, 1996). Part II: Selecting Papers Covering the 20th Century.

    ERIC Educational Resources Information Center

    American Journalism Historians' Association.

    The 17 papers in this collection all deal with 20th-century journalism, journalists, and mass media. The papers and their authors are: "Building One's Own Gallows: The Trade Publications' Reaction to a Federal Shield Law, 1972-1974" (Karla Gower); "The Useful Ogre: Sweden's Use and Views of American Television, 1956-62" (Ulf Jonas Bjork); "Black…

  18. A User-Centered Approach to the Design of an Expert System for Training.

    ERIC Educational Resources Information Center

    Borges, Marcos Augusto Francisco; Baranauskas, M. Cecilia C.

    1998-01-01

    Reports on a research project designed to develop an intelligent computer-based learning environment of industrial applications. "Jonas," an expert system, is part of a modeling/simulation environment which enables shop-floor workers to test and put new philosophies of work into practice in the context of manufacture. The approach focuses on the…

  19. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (74th, Boston, Massachusetts, August 7-10, 1991). Part VIII: Journalism and Media History, Section B.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    Section B of the Journalism and Media History section of the proceedings contains the following 14 papers: "Rethinking the Questions: An Essay on Writing Journalism History from a Feminist Perspective" (Agnes Hooper Gottlieb); "International Standards for Journalists: The Activities of the Press Congress of the World, 1921-26" (Ulf Jonas Bjork);…

  20. Path integral approach to two-dimensional QCD in the light-front frame

    NASA Astrophysics Data System (ADS)

    Gaete, P.; Gamboa, J.; Schmidt, I.

    1994-05-01

    Two-dimensional quantum chromodynamics in the light-front frame is studied following Hamiltonian methods. The theory is quantized using the path integral formalism and an effective theory similar to the Nambu-Jona-Lasinio model is obtained. Confinement in two dimensions is derived by analyzing directly the constraints in the path integral.

  1. Drug testing in the patient: toward personalized cancer treatment.

    PubMed

    Coombes, R Charles

    2015-04-22

    Two different devices show that delivery of cancer drugs directly into tumors in vivo can indicate cancer sensitivity; if implemented in clinical practice, these devices have the potential to reduce indiscriminate drug use, to improve survival, and to reduce unnecessary adverse effects (Jonas et al. and Klinghoffer et al., this issue). PMID:25904739

  2. Pre-Treatment with Allopurinol or Uricase Attenuates Barrier Dysfunction but Not Inflammation during Murine Ventilator-Induced Lung Injury

    PubMed Central

    Kuipers, Maria T.; Aslami, Hamid; Vlaar, Alexander P. J.; Juffermans, Nicole P.; Tuip-de Boer, Anita M.; Hegeman, Maria A.; Jongsma, Geartsje; Roelofs, Joris J. T. H.; van der Poll, Tom; Schultz, Marcus J.; Wieland, Catharina W.

    2012-01-01

    Introduction Uric acid released from injured tissue is considered a major endogenous danger signal and local instillation of uric acid crystals induces acute lung inflammation via activation of the NLRP3 inflammasome. Ventilator-induced lung injury (VILI) is mediated by the NLRP3 inflammasome and increased uric acid levels in lung lavage fluid are reported. We studied levels in human lung injury and the contribution of uric acid in experimental VILI. Methods Uric acid levels in lung lavage fluid of patients with acute lung injury (ALI) were determined. In a different cohort of cardiac surgery patients, uric acid levels were correlated with pulmonary leakage index. In a mouse model of VILI the effect of allopurinol (inhibits uric acid synthesis) and uricase (degrades uric acid) pre-treatment on neutrophil influx, up-regulation of adhesion molecules, pulmonary and systemic cytokine levels, lung pathology, and regulation of receptors involved in the recognition of uric acid was studied. In addition, total protein and immunoglobulin M in lung lavage fluid and pulmonary wet/dry ratios were measured as markers of alveolar barrier dysfunction. Results Uric acid levels increased in ALI patients. In cardiac surgery patients, elevated levels correlated significantly with the pulmonary leakage index. Allopurinol or uricase treatment did not reduce ventilator-induced inflammation, IκB-α degradation, or up-regulation of NLRP3, Toll-like receptor 2, and Toll-like receptor 4 gene expression in mice. Alveolar barrier dysfunction was attenuated which was most pronounced in mice pre-treated with allopurinol: both treatment strategies reduced wet/dry ratio, allopurinol also lowered total protein and immunoglobulin M levels. Conclusions Local uric acid levels increase in patients with ALI. In mice, allopurinol and uricase attenuate ventilator-induced alveolar barrier dysfunction. PMID:23226314

  3. Natural coordinates for specification of eye movements.

    PubMed

    Clement, R A

    1991-01-01

    Tweed and Vilis (Journal of Neurophysiology, 58, 832-849, 1987) have argued that quaternion algebra provides the most appropriate description of the rotations of the eye, and have derived a three-dimensional model of gaze control based on quaternion operations. Euler angles give a simpler description of the rotations of the eye, and can also be used to formulate an alternative version of the three-dimensional gaze control model. Comparison of the two versions of the model highlights the distinction between the functional predictions of the model, and the predictions which depend only on the choice of mathematical descriptions. PMID:1771787

  4. Computational Models of Ventilator Induced Lung Injury and Surfactant Dysfunction

    PubMed Central

    Bates, Jason H.T.; Smith, Bradford J.; Allen, Gilman B.

    2014-01-01

    Managing acute respiratory distress syndrome (ARDS) invariably involves the administration of mechanical ventilation, the challenge being to avoid the iatrogenic sequellum known as ventilator-induced lung injury (VILI). Devising individualized ventilation strategies in ARDS requires that patient-specific lung physiology be taken into account, and this is greatly aided by the use of computational models of lung mechanical function that can be matched to physiological measurements made in a given patient. In this review, we discuss recent models that have the potential to serve as the basis for devising minimally injurious modes of mechanical ventilation in ARDS patients. PMID:26904138

  5. An approach to ventilation in acute respiratory distress syndrome

    PubMed Central

    Houston, Patricia

    2000-01-01

    Appropriate management of patients with acute respiratory distress syndrome (ARDS) represents a challenge for physicians working in the critical care environment. Significant advances have been made in understanding the pathophysiology of ARDS. There is also an increasing appreciation of the role of ventilator-induced lung injury (VILI). VILI is most likely related to several different aspects of ventilator management: barotrauma due to high peak airway pressures, lung overdistension or volutrauma due to high transpulmonary pressures, alveolar membrane damage due to insufficient positive end-expiratory pressure levels and oxygen-related cell toxicity. Various lung protective strategies have been suggested to minimize the damage caused by conventional modes of ventilation. These include the use of pressure- and volume-limited ventilation, the use of the prone position in the management of ARDS, and extracorporeal methods of oxygen delivery and carbon dioxide removal. Although the death rate resulting from ARDS has been declining over the past 10 years, there is no evidence that any specific treatment or change in approach to ventilation is the cause of this improved survival. PMID:10948686

  6. Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study

    PubMed Central

    Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

    2014-01-01

    Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

  7. Histopathological changes and mRNA expression in lungs of horses after inhalation anaesthesia with different ventilation strategies.

    PubMed

    Hopster, K; Jacobson, B; Hopster-Iversen, C; Rohn, K; Kästner, S B R

    2016-08-01

    Inappropriate mechanical ventilation can lead to ventilator-induced lung injury (VILI). Aim of this study was to evaluate the effects of inhalation anaesthesia and ventilation with and without recruitment (RM) and PEEP titration on alveolar integrity in horses. Twenty-three horses were divided into 4 groups (group OLC ventilated with OLC, group IPPV ventilated with intermittent positive pressure ventilation, group NV non-ventilated, and group C non-anaesthetized control group). After sedation with xylazine and induction with diazepam and ketamine anaesthetized horses were under isoflurane anaesthesia for 5.5h. The horses were euthanized and tissue samples of the dependent and non-dependent lung areas were collected. Histopathological examinations of the lung tissue as well as relative quantification of mRNA of IL-1β, IL-6, iNOS, MMP1 and MMP9 by PCR were performed. Horses of group OLC had significantly less alveolar congestion and atelectasis but greater alveolar overdistension compared to groups NV and IPPV. In groups OLC and group IPPV an increase in IL-1β/6 and MMP1/9 was detected compared to groups NV and C. In conclusion, in breathing spontaneously or IPPV-ventilated horses a higher degree of atelectasis was detected, whereas in OLC-ventilated horses a higher degree of overdistention was present. Elevated levels in IL and MMP might be early signs of VILI in ventilated horses. PMID:27473968

  8. The physical basis of ventilator-induced lung injury

    PubMed Central

    Plataki, Maria; Hubmayr, Rolf D

    2010-01-01

    Although mechanical ventilation (MV) is a life-saving intervention for patients with acute respiratory distress syndrome (ARDS), it can aggravate or cause lung injury, known as ventilator-induced lung injury (VILI). The biophysical characteristics of heterogeneously injured ARDS lungs increase the parenchymal stress associated with breathing, which is further aggravated by MV. Cells, in particular those lining the capillaries, airways and alveoli, transform this strain into chemical signals (mechanotransduction). The interaction of reparative and injurious mechanotransductive pathways leads to VILI. Several attempts have been made to identify clinical surrogate measures of lung stress/strain (e.g., density changes in chest computed tomography, lower and upper inflection points of the pressure–volume curve, plateau pressure and inflammatory cytokine levels) that could be used to titrate MV. However, uncertainty about the topographical distribution of stress relative to that of the susceptibility of the cells and tissues to injury makes the existence of a single ‘global’ stress/strain injury threshold doubtful. PMID:20524920

  9. Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

    PubMed Central

    Nelson, Kevin; Bobba, Christopher; Eren, Emre; Spata, Tyler; Tadres, Malak; Hayes,, Don; Black, Sylvester M.

    2015-01-01

    The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and “pearls of wisdom”/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible. PMID:25741794

  10. Method of isolated ex vivo lung perfusion in a rat model: lessons learned from developing a rat EVLP program.

    PubMed

    Nelson, Kevin; Bobba, Christopher; Eren, Emre; Spata, Tyler; Tadres, Malak; Hayes, Don; Black, Sylvester M; Ghadiali, Samir; Whitson, Bryan A

    2015-01-01

    The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and "pearls of wisdom"/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible. PMID:25741794

  11. Bixin protects mice against ventilation-induced lung injury in an NRF2-dependent manner

    PubMed Central

    Tao, Shasha; Rojo de la Vega, Montserrat; Quijada, Hector; Wondrak, Georg T.; Wang, Ting; Garcia, Joe G. N.; Zhang, Donna D.

    2016-01-01

    Mechanical ventilation (MV) is a therapeutic intervention widely used in the clinic to assist patients that have difficulty breathing due to lung edema, trauma, or general anesthesia. However, MV causes ventilator-induced lung injury (VILI), a condition characterized by increased permeability of the alveolar-capillary barrier that results in edema, hemorrhage, and neutrophil infiltration, leading to exacerbated lung inflammation and oxidative stress. This study explored the feasibility of using bixin, a canonical NRF2 inducer identified during the current study, to ameliorate lung damage in a murine VILI model. In vitro, bixin was found to activate the NRF2 signaling pathway through blockage of ubiquitylation and degradation of NRF2 in a KEAP1-C151 dependent manner; intraperitoneal (IP) injection of bixin led to pulmonary upregulation of the NRF2 response in vivo. Remarkably, IP administration of bixin restored normal lung morphology and attenuated inflammatory response and oxidative DNA damage following MV. This observed beneficial effect of bixin derived from induction of the NRF2 cytoprotective response since it was only observed in Nrf2+/+ but not in Nrf2−/− mice. This is the first study providing proof-of-concept that NRF2 activators can be developed into pharmacological agents for clinical use to prevent patients from lung injury during MV treatment. PMID:26729554

  12. Mechanical stress activates xanthine oxidoreductase through MAP kinase-dependent pathways.

    PubMed

    Abdulnour, Raja-Elie E; Peng, Xinqi; Finigan, Jay H; Han, Eugenia J; Hasan, Emile J; Birukov, Konstantin G; Reddy, Sekhar P; Watkins, James E; Kayyali, Usamah S; Garcia, Joe G N; Tuder, Rubin M; Hassoun, Paul M

    2006-09-01

    Xanthine oxidoreductase (XOR) plays a prominent role in acute lung injury because of its ability to generate reactive oxygen species. We investigated the role of XOR in ventilator-induced lung injury (VILI). Male C57BL/6J mice were assigned to spontaneous ventilation (sham) or mechanical ventilation (MV) with low (7 ml/kg) and high tidal volume (20 ml/kg) for 2 h after which lung XOR activity and expression were measured and the effect of the specific XOR inhibitor allopurinol on pulmonary vascular leakage was examined. In separate experiments, rat pulmonary microvascular endothelial cells (RPMECs) were exposed to cyclic stretch (5% and 18% elongation, 20 cycles/min) for 2 h before intracellular XOR activity measurement. Lung XOR activity was significantly increased at 2 h of MV without changes in XOR expression. There was evidence of p38 MAP kinase, ERK1/2, and ERK5 phosphorylation, but no change in JNK phosphorylation. Evans blue dye extravasation and bronchoalveolar lavage protein concentration were significantly increased in response to MV, changes that were significantly attenuated by pretreatment with allopurinol. Cyclic stretch of RPMECs also caused MAP kinase phosphorylation and a 1.7-fold increase in XOR activity, which was completely abrogated by pretreatment of the cells with specific MAP kinase inhibitors. We conclude that XOR enzymatic activity is significantly increased by mechanical stress via activation of p38 MAP kinase and ERK and plays a critical role in the pathogenesis of pulmonary edema associated with VILI. PMID:16632522

  13. Ventilator-induced lung injury upregulates and activates gelatinases and EMMPRIN: attenuation by the synthetic matrix metalloproteinase inhibitor, Prinomastat (AG3340).

    PubMed

    Foda, H D; Rollo, E E; Drews, M; Conner, C; Appelt, K; Shalinsky, D R; Zucker, S

    2001-12-01

    Mechanical ventilation has become an indispensable therapeutic modality for patients with respiratory failure. However, a serious potential complication of MV is the newly recognized ventilator-induced acute lung injury. There is strong evidence suggesting that matrix metalloproteinases (MMPs) play an important role in the development of acute lung injury. Another factor to be considered is extracellular matrix metalloproteinase inducer (EMMPRIN). EMMPRIN is responsible for inducing fibroblasts to produce/secrete MMPs. In this report we sought to determine: (1) the role played by MMPs and EMMPRIN in the development of ventilator-induced lung injury (VILI) in an in vivo rat model of high volume ventilation; and (2) whether the synthetic MMP inhibitor Prinomastat (AG3340) could prevent this type of lung injury. We have demonstrated that high volume ventilation caused acute lung injury. This was accompanied by an upregulation of gelatinase A, gelatinase B, MT1-MMP, and EMMPRIN mRNA demonstrated by in situ hybridization. Pretreatment with the MMP inhibitor Prinomastat attenuated the lung injury caused by high volume ventilation. Our results suggest that MMPs play an important role in the development of VILI in rat lungs and that the MMP-inhibitor Prinomastat is effective in attenuating this type of lung injury. PMID:11726397

  14. What does low energy physics tell us about the zero momentum gluon propagator?

    SciTech Connect

    Costa, P.; Oliveira, O.; Silva, P. J.

    2011-05-23

    The connection between QCD, a nonlocal Nambu-Jona-Lasinio type model and the Landau gauge gluon propagator is explored. This two point function is parameterized by a functional form which is compatible with Dyson-Schwinger and lattice QCD results. Demanding the nonlocal model to reproduce the experimental values for the pion mass, the pion decay constant, {Gamma}{sub {pi}{yields}{gamma}{gamma}} and the light quark condensate we conclude that low energy physics does not distinguish between the so-called decoupling and scaling solutions of the Dyson-Schwinger equations. This result means that, provided that the model parameters are chosen appropriately, one is free to choose any of the above scenarios. Furthermore, the nonlocal Nambu-Jona-Lasinio quark model considered here is chiral invariant and satisfies the GMOR relation at the 1% level of precision.

  15. Portrait

    PubMed Central

    Granoff, Dan M.

    2013-01-01

    Born in 1944, I grew up in a world in which polio was both a gripping fear and real threat. Then in a matter of a few years—polio was eradicated by a vaccine developed by Jonas Salk. Later I learned that Salk’s efforts were built on pioneering work of many others, including John Enders, Thomas Weller and Frederick Robbins (Nobelists, 1954), and David Bodian, who pioneered studies of polio pathogenesis and immunity. Bodian became my teacher in medical school, and Robbins became a colleague. Later, Salk, Robbins and I shared a platform at an infectious diseases symposium, and I was privileged to speak at Robbins’ retirement. But that gets ahead of my story. In January 1956, at age 12 y, I received my first of dose of the “Salk” vaccine. Other kids had pictures of athletes in their rooms; I had a picture of Jonas Salk. PMID:23807081

  16. Portrait: coincidences, convergences and opportunities.

    PubMed

    Granoff, Dan M

    2013-05-01

    Born in 1944, I grew up in a world in which polio was both a gripping fear and real threat. Then in a matter of a few years-polio was eradicated by a vaccine developed by Jonas Salk. Later I learned that Salk's efforts were built on pioneering work of many others, including John Enders, Thomas Weller and Frederick Robbins (Nobelists, 1954), and David Bodian, who pioneered studies of polio pathogenesis and immunity. Bodian became my teacher in medical school, and Robbins became a colleague. Later, Salk, Robbins and I shared a platform at an infectious diseases symposium, and I was privileged to speak at Robbins' retirement. But that gets ahead of my story. In January 1956, at age 12 y, I received my first of dose of the "Salk" vaccine. Other kids had pictures of athletes in their rooms; I had a picture of Jonas Salk. PMID:23807081

  17. Phase diagram of quark-antiquark and diquark condensates in the 3-dimensional Gross-Neveu model with the 4-component spinor representation

    SciTech Connect

    Kohyama, Hiroaki

    2008-07-01

    We construct the phase diagram of the quark-antiquark and diquark condensates at finite temperature and density in the 2+1 dimensional (3D) two flavor massless Gross-Neveu (GN) model with the 4-component quarks. In contrast to the case of the 2-component quarks, there appears the coexisting phase of the quark-antiquark and diquark condensates. This is the crucial difference between the 2-component and 4-component quark cases in the 3D GN model. The coexisting phase is also seen in the 4D Nambu Jona-Lasinio model. Then we see that the 3D GN model with the 4-component quarks bears closer resemblance to the 4D Nambu Jona-Lasinio model.

  18. Nucleon quark distributions in a covariant quark-diquark model

    SciTech Connect

    Ian Cloet; W. Bentz; Anthony Thomas

    2005-04-01

    Spin-dependent and spin-independent quark light-cone momentum distributions and structure functions are calculated for the nucleon. We utilize a modified Nambu-Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquarks channels are included. We find excellent agreement between our model results and empirical data.

  19. Transparent Dirac potentials in one dimension: The time-dependent case

    NASA Astrophysics Data System (ADS)

    Dunne, Gerald V.; Thies, Michael

    2013-12-01

    We generalize the original derivation of transparent, static Schrödinger potentials by Kay and Moses, to obtain a large class of time-dependent transparent Dirac potentials in one spatial dimension. They contain previously found transparent potentials as special cases and play a key role in the semiclassical solution of the (1+1)-dimensional, fermionic quantum field theories of Gross-Neveu and Nambu-Jona-Lasinio types.

  20. Quark confinement in a constituent quark model

    SciTech Connect

    Langfeld, K.; Rho, M.

    1995-07-01

    On the level of an effective quark theory, we define confinement by the absence of quark anti-quark thresholds in correlation function. We then propose a confining Nambu-Jona-Lasinio-type model. The confinement is implemented in analogy to Anderson localization in condensed matter systems. We study the model`s phase structure as well as its behavior under extreme conditions, i.e. high temperature and/or high density.

  1. QCD Relics of Astrophysical Relevance

    SciTech Connect

    Ribeiro, J. Emilio F. T.

    2011-05-24

    The connection between effective-actions and generalizations of Nambu-Jona-Lasinio models is discussed. We suggest the possibility of creation in the early Universe of stable domains of radius a few kilometers wide. Such domains should appear dark to an external observer. The insulation of the domains from the outer world, a consequence of the joint role played by gravity and the existence of two orthogonal Fock spaces could have allowed them to survive untill present days.

  2. The axial anomaly and the dynamical breaking of chiral symmetry

    SciTech Connect

    Gross, Franz; Ito, Hiroshi; Buck, Warren

    1991-10-01

    Using the quark triangle diagram for the Adler-Bell-Jackiw axial anomaly, we calculate the form factor for the {gamma}{sup *}{pi}{sup 0}{yields}{gamma} transition. This form factor depends on the quark mass, and we predict the right behavior with m{sub q}{approx_equal}250 MeV, the same quark mass generated by the dynamical breaking of chiral symmetry through a Nambu-Jona-Lasinio mechanism.

  3. Quark-mass dependence of the three-flavor QCD phase diagram at zero and imaginary chemical potential: Model prediction

    SciTech Connect

    Sasaki, Takahiro; Sakai, Yuji; Yahiro, Masanobu; Kouno, Hiroaki

    2011-11-01

    We draw the three-flavor phase diagram as a function of light- and strange-quark masses for both zero and imaginary quark-number chemical potential, using the Polyakov-loop extended Nambu-Jona-Lasinio model with an effective four-quark vertex depending on the Polyakov loop. The model prediction is qualitatively consistent with 2+1 flavor lattice QCD prediction at zero chemical potential and with degenerate three-flavor lattice QCD prediction at imaginary chemical potential.

  4. Exploring the role of model parameters and regularization procedures in the thermodynamics of the PNJL model

    SciTech Connect

    Ruivo, M. C.; Costa, P.; Sousa, C. A. de; Hansen, H.

    2010-08-05

    The equation of state and the critical behavior around the critical end point are studied in the framework of the Polyakov-Nambu-Jona-Lasinio model. We prove that a convenient choice of the model parameters is crucial to get the correct description of isentropic trajectories. The physical relevance of the effects of the regularization procedure is insured by the agreement with general thermodynamic requirements. The results are compared with simple thermodynamic expectations and lattice data.

  5. Variance analysis. Part II, The use of computers.

    PubMed

    Finkler, S A

    1991-09-01

    This is the second in a two-part series on variance analysis. In the first article (JONA, July/August 1991), the author discussed flexible budgeting, including the calculation of price, quantity, volume, and acuity variances. In this second article, the author focuses on the use of computers by nurse managers to aid in the process of calculating, understanding, and justifying variances. PMID:1919788

  6. Investigation of possible structures of hybrid neutron stars

    SciTech Connect

    Paoli, M. G.; Menezes, D. P.

    2010-11-12

    This work investigates the structure of hybrid stars built in two different ways. The first one considers the existence of a mixed phase at intermediate stellar densities. The second implies the inexistence of this mixed phase. In this case, the hadron phase and the quark phase are in direct contact. We use the non-linear Walecka model (NLWM) to describe the hadron phase and the Nambu-Jona-Lasinio model (NJL) for the quark phase.

  7. Quark matter under strong magnetic fields in chiral models

    SciTech Connect

    Rabhi, Aziz; Providencia, Constanca

    2011-05-15

    The chiral model is used to describe quark matter under strong magnetic fields and is compared to other models, the MIT bag model and the two-flavor Nambu-Jona-Lasinio model. The effect of vacuum corrections due to the magnetic field is discussed. It is shown that if the magnetic-field vacuum corrections are not taken into account explicitly, the parameters of the models should be fitted to low-density meson properties in the presence of the magnetic field.

  8. Domain growth and ordering kinetics in dense quark matter

    SciTech Connect

    Singh, A.; Puri, S.; Mishra, H.

    2012-06-15

    The kinetics of chiral transitions in quark matter is studied in a two-flavor Nambu-Jona-Lasinio model. We focus on the phase-ordering dynamics subsequent to a temperature quench from the massless quark phase to the massive quark phase. We study the dynamics by considering a phenomenological model (Ginzburg-Landau free-energy functional). The morphology of the ordering system is characterized by the scaling of the order-parameter correlation function.

  9. Quark matter subject to strong magnetic fields: phase diagram and applications

    NASA Astrophysics Data System (ADS)

    Menezes, Débora P.; Pinto, Marcus B.; Providência, Constança; Costa, Pedro; Ferreira, Márcio; Castro, Luis B.

    2015-07-01

    In the present work we are interested in understanding various properties of quark matter subject to strong magnetic fields described by the Nambu-Jona-Lasinio model with Polyakov loop. We start by analysing the differences arising from two different vector interactions in the Lagrangian densities, at zero temperature, and apply the results to stellar matter. We then investigate the position of the critical end point for different chemical potential and density scenarios.

  10. Chiral symmetry and the charge asymmetry of the s s distribution in a proton

    SciTech Connect

    Burkardt, M.

    1991-05-01

    Based on a simple K-cloud model, as well as the Gross-Neveu and the Nambu-Jona-Lasinio model, it is predicted that the s{bar s} sea in a proton is not charge symmetric at large Bjorken-x. The s quarks are shifted to larger values of x{sub bj} than the {bar s} quarks. Furthermore these large x{sub bj} s quarks carry a negative polarization. 9 refs., 2 figs.

  11. Emergency Preservation and Resuscitation Trial: A Philosophical Justification for Non-Voluntary Enrollment.

    PubMed

    Tigard, Daniel

    2016-06-01

    In a current clinical trial for Emergency Preservation and Resuscitation (EPR), Dr. Samuel Tisherman of the University of Maryland aims to induce therapeutic hypothermia in order to 'buy time' for operating on victims of severe exsanguination. While recent publicity has framed this controversial procedure as 'killing a patient to save his life', the US Army and Acute Care Research appear to support the study on the grounds that such patients already face low chances of survival. Given that enrollment in the trial must be non-voluntary, the study has received an exemption from federal standards for obtaining informed consent. How exactly, if at all, is non-voluntary enrollment morally justifiable? In this essay, I appeal to the notable work of Hans Jonas in an effort to defend the EPR trial's use of non-voluntary enrollment. It is often thought and, as I show, it may appear that Jonas has called for the end of experimental medical practice. Still, I derive from Jonas a principle of double-effect upon which physicians may be seen as morally permitted to pursue innovations in emergency medicine but only as a byproduct of pursuing therapeutic success. With this position, I argue that the EPR trial can be granted a stronger philosophical justification than simply waiving the requirement of obtaining informed consent. The double-effect justification would obtain, perhaps regardless of the success of such innovative procedures as therapeutic hypothermia. PMID:26644358

  12. GADD45a Promoter Regulation by a Functional Genetic Variant Associated with Acute Lung Injury

    PubMed Central

    Mitra, Sumegha; Wade, Michael S.; Sun, Xiaoguang; Moldobaeva, Nurgul; Flores, Carlos; Ma, Shwu-Fan; Zhang, Wei

    2014-01-01

    Rationale Growth arrest DNA damage inducible alpha (GADD45a) is a stress-induced gene we have shown to participate in the pathophysiology of ventilator-induced lung injury (VILI) via regulation of mechanical stress-induced Akt ubiquitination and phosphorylation. The regulation of GADD45a expression by mechanical stress and its relationship with acute lung injury (ALI) susceptibility and severity, however, remains unknown. Objectives We examined mechanical stress-dependent regulatory elements (MSRE) in the GADD45a promoter and the contribution of promoter polymorphisms in GADD45a expression and ALI susceptibility. Methods and Results Initial studies in GADD45a knockout and heterozygous mice confirmed the relationship of GADD45a gene dose to VILI severity. Human lung endothelial cells (EC) transfected with a luciferase vector containing the full length GADD45a promoter sequence (−771 to +223) demonstrated a >4 fold increase in GADD45a expression in response to 18% cyclic stretch (CS, 4 h) compared to static controls while specific promoter regions harboring CS-dependent MSRE were identified using vectors containing serial deletion constructs of the GADD45a promoter. In silico analyses of GADD45a promoter region (−371 to −133) revealed a potential binding site for specificity protein 1 (SP1), a finding supported by confirmed SP1 binding with the GADD45a promoter and by the significant attenuation of CS-dependent GADD45a promoter activity in response to SP1 silencing. Separately, case-control association studies revealed a significant association of a GADD45a promoter SNP at −589 (rs581000, G>C) with reduced ALI susceptibility. Subsequently, we found allelic variation of this SNP is associated with both differential GADD45a expression in mechanically stressed EC (18% CS, 4 h) and differential binding site of interferon regulatory factor 7 (IRF7) at this site. Conclusion These results strongly support a functional role for GADD45a in ALI/VILI and identify a

  13. Comparison between Variable and Conventional Volume-Controlled Ventilation on Cardiorespiratory Parameters in Experimental Emphysema

    PubMed Central

    Henriques, Isabela; Padilha, Gisele A.; Huhle, Robert; Wierzchon, Caio; Miranda, Paulo J. B.; Ramos, Isalira P.; Rocha, Nazareth; Cruz, Fernanda F.; Santos, Raquel S.; de Oliveira, Milena V.; Souza, Sergio A.; Goldenberg, Regina C.; Luiz, Ronir R.; Pelosi, Paolo; de Abreu, Marcelo G.; Silva, Pedro L.; Rocco, Patricia R. M.

    2016-01-01

    Emphysema is characterized by loss of lung tissue elasticity and destruction of structures supporting alveoli and capillaries. The impact of mechanical ventilation strategies on ventilator-induced lung injury (VILI) in emphysema is poorly defined. New ventilator strategies should be developed to minimize VILI in emphysema. The present study was divided into two protocols: (1) characterization of an elastase-induced emphysema model in rats and identification of the time point of greatest cardiorespiratory impairment, defined as a high specific lung elastance associated with large right ventricular end-diastolic area; and (2) comparison between variable (VV) and conventional volume-controlled ventilation (VCV) on lung mechanics and morphometry, biological markers, and cardiac function at that time point. In the first protocol, Wistar rats (n = 62) received saline (SAL) or porcine pancreatic elastase (ELA) intratracheally once weekly for 4 weeks, respectively. Evaluations were performed 1, 3, 5, or 8 weeks after the last intratracheal instillation of saline or elastase. After identifying the time point of greatest cardiorespiratory impairment, an additional 32 Wistar rats were randomized into the SAL and ELA groups and then ventilated with VV or VCV (n = 8/group) [tidal volume (VT) = 6 mL/kg, positive end-expiratory pressure (PEEP) = 3 cmH2O, fraction of inspired oxygen (FiO2) = 0.4] for 2 h. VV was applied on a breath-to-breath basis as a sequence of randomly generated VT values (mean VT = 6 mL/kg), with a 30% coefficient of variation. Non-ventilated (NV) SAL and ELA animals were used for molecular biology analysis. The time point of greatest cardiorespiratory impairment, was observed 5 weeks after the last elastase instillation. At this time point, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (CINC)-1, amphiregulin, angiopoietin (Ang)-2, and vascular endothelial growth factor (VEGF) mRNA levels were higher in ELA compared to SAL. In ELA animals

  14. Heliox Allows for Lower Minute Volume Ventilation in an Animal Model of Ventilator-Induced Lung Injury

    PubMed Central

    Beurskens, Charlotte J.; Aslami, Hamid; de Beer, Friso M.; Vroom, Margreeth B.; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P.

    2013-01-01

    Background Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2) diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator–induced lung injury. Methods Sprague-Dawley rats (N=8 per group) were mechanically ventilated with heliox (50% oxygen; 50% helium). Controls received a standard gas mixture (50% oxygen; 50% air). VILI was induced by application of tidal volumes of 15 mL kg-1; lung protective ventilated animals were ventilated with 6 mL kg-1. Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO2 within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF) was obtained. Data are mean (SD). Results VILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324) vs. 290 (181) μg mL-1; p<0.05) and IL-6 levels (640 (8.7) vs. 206 (8.7) pg mL-1; p<0.05), whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123±0.6 vs. 146±8.9 mL min-1, P<0.001), due to a decrease in respiratory rate (22 (0.4) vs. 25 (2.1) breaths per minute; p<0.05), while pCO2 levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects. Conclusions Heliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of severe acidosis

  15. Bayesian inference of the lung alveolar spatial model for the identification of alveolar mechanics associated with acute respiratory distress syndrome

    NASA Astrophysics Data System (ADS)

    Christley, Scott; Emr, Bryanna; Ghosh, Auyon; Satalin, Josh; Gatto, Louis; Vodovotz, Yoram; Nieman, Gary F.; An, Gary

    2013-06-01

    Acute respiratory distress syndrome (ARDS) is acute lung failure secondary to severe systemic inflammation, resulting in a derangement of alveolar mechanics (i.e. the dynamic change in alveolar size and shape during tidal ventilation), leading to alveolar instability that can cause further damage to the pulmonary parenchyma. Mechanical ventilation is a mainstay in the treatment of ARDS, but may induce mechano-physical stresses on unstable alveoli, which can paradoxically propagate the cellular and molecular processes exacerbating ARDS pathology. This phenomenon is called ventilator induced lung injury (VILI), and plays a significant role in morbidity and mortality associated with ARDS. In order to identify optimal ventilation strategies to limit VILI and treat ARDS, it is necessary to understand the complex interplay between biological and physical mechanisms of VILI, first at the alveolar level, and then in aggregate at the whole-lung level. Since there is no current consensus about the underlying dynamics of alveolar mechanics, as an initial step we investigate the ventilatory dynamics of an alveolar sac (AS) with the lung alveolar spatial model (LASM), a 3D spatial biomechanical representation of the AS and its interaction with airflow pressure and the surface tension effects of pulmonary surfactant. We use the LASM to identify the mechanical ramifications of alveolar dynamics associated with ARDS. Using graphical processing unit parallel algorithms, we perform Bayesian inference on the model parameters using experimental data from rat lung under control and Tween-induced ARDS conditions. Our results provide two plausible models that recapitulate two fundamental hypotheses about volume change at the alveolar level: (1) increase in alveolar size through isotropic volume change, or (2) minimal change in AS radius with primary expansion of the mouth of the AS, with the implication that the majority of change in lung volume during the respiratory cycle occurs in the

  16. Bayesian inference of the lung alveolar spatial model for the identification of alveolar mechanics associated with acute respiratory distress syndrome.

    PubMed

    Christley, Scott; Emr, Bryanna; Ghosh, Auyon; Satalin, Josh; Gatto, Louis; Vodovotz, Yoram; Nieman, Gary F; An, Gary

    2013-06-01

    Acute respiratory distress syndrome (ARDS) is acute lung failure secondary to severe systemic inflammation, resulting in a derangement of alveolar mechanics (i.e. the dynamic change in alveolar size and shape during tidal ventilation), leading to alveolar instability that can cause further damage to the pulmonary parenchyma. Mechanical ventilation is a mainstay in the treatment of ARDS, but may induce mechano-physical stresses on unstable alveoli, which can paradoxically propagate the cellular and molecular processes exacerbating ARDS pathology. This phenomenon is called ventilator induced lung injury (VILI), and plays a significant role in morbidity and mortality associated with ARDS. In order to identify optimal ventilation strategies to limit VILI and treat ARDS, it is necessary to understand the complex interplay between biological and physical mechanisms of VILI, first at the alveolar level, and then in aggregate at the whole-lung level. Since there is no current consensus about the underlying dynamics of alveolar mechanics, as an initial step we investigate the ventilatory dynamics of an alveolar sac (AS) with the lung alveolar spatial model (LASM), a 3D spatial biomechanical representation of the AS and its interaction with airflow pressure and the surface tension effects of pulmonary surfactant. We use the LASM to identify the mechanical ramifications of alveolar dynamics associated with ARDS. Using graphical processing unit parallel algorithms, we perform Bayesian inference on the model parameters using experimental data from rat lung under control and Tween-induced ARDS conditions. Our results provide two plausible models that recapitulate two fundamental hypotheses about volume change at the alveolar level: (1) increase in alveolar size through isotropic volume change, or (2) minimal change in AS radius with primary expansion of the mouth of the AS, with the implication that the majority of change in lung volume during the respiratory cycle occurs in the

  17. Comparison between Variable and Conventional Volume-Controlled Ventilation on Cardiorespiratory Parameters in Experimental Emphysema.

    PubMed

    Henriques, Isabela; Padilha, Gisele A; Huhle, Robert; Wierzchon, Caio; Miranda, Paulo J B; Ramos, Isalira P; Rocha, Nazareth; Cruz, Fernanda F; Santos, Raquel S; de Oliveira, Milena V; Souza, Sergio A; Goldenberg, Regina C; Luiz, Ronir R; Pelosi, Paolo; de Abreu, Marcelo G; Silva, Pedro L; Rocco, Patricia R M

    2016-01-01

    Emphysema is characterized by loss of lung tissue elasticity and destruction of structures supporting alveoli and capillaries. The impact of mechanical ventilation strategies on ventilator-induced lung injury (VILI) in emphysema is poorly defined. New ventilator strategies should be developed to minimize VILI in emphysema. The present study was divided into two protocols: (1) characterization of an elastase-induced emphysema model in rats and identification of the time point of greatest cardiorespiratory impairment, defined as a high specific lung elastance associated with large right ventricular end-diastolic area; and (2) comparison between variable (VV) and conventional volume-controlled ventilation (VCV) on lung mechanics and morphometry, biological markers, and cardiac function at that time point. In the first protocol, Wistar rats (n = 62) received saline (SAL) or porcine pancreatic elastase (ELA) intratracheally once weekly for 4 weeks, respectively. Evaluations were performed 1, 3, 5, or 8 weeks after the last intratracheal instillation of saline or elastase. After identifying the time point of greatest cardiorespiratory impairment, an additional 32 Wistar rats were randomized into the SAL and ELA groups and then ventilated with VV or VCV (n = 8/group) [tidal volume (VT) = 6 mL/kg, positive end-expiratory pressure (PEEP) = 3 cmH2O, fraction of inspired oxygen (FiO2) = 0.4] for 2 h. VV was applied on a breath-to-breath basis as a sequence of randomly generated VT values (mean VT = 6 mL/kg), with a 30% coefficient of variation. Non-ventilated (NV) SAL and ELA animals were used for molecular biology analysis. The time point of greatest cardiorespiratory impairment, was observed 5 weeks after the last elastase instillation. At this time point, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (CINC)-1, amphiregulin, angiopoietin (Ang)-2, and vascular endothelial growth factor (VEGF) mRNA levels were higher in ELA compared to SAL. In ELA animals

  18. Inhibitor of neuronal nitric oxide synthase improves gas exchange in ventilator-induced lung injury after pneumonectomy

    PubMed Central

    2012-01-01

    Background Mechanical ventilation with high tidal volumes may cause ventilator-induced lung injury (VILI) and enhanced generation of nitric oxide (NO). We demonstrated in sheep that pneumonectomy followed by injurious ventilation promotes pulmonary edema. We wished both to test the hypothesis that neuronal NOS (nNOS), which is distributed in airway epithelial and neuronal tissues, could be involved in the pathogenesis of VILI and we also aimed at investigating the influence of an inhibitor of nNOS on the course of VILI after pneumonectomy. Methods Anesthetized sheep underwent right pneumonectomy, mechanical ventilation with tidal volumes (VT) of 6 mL/kg and FiO2 0.5, and were subsequently randomized to a protectively ventilated group (PROTV; n = 8) keeping VT and FiO2 unchanged, respiratory rate (RR) 25 inflations/min and PEEP 4 cm H2O for the following 8 hrs; an injuriously ventilated group with VT of 12 mL/kg, zero end-expiratory pressure, and FiO2 and RR unchanged (INJV; n = 8) and a group, which additionally received the inhibitor of nNOS, 7-nitroindazole (NI) 1.0 mg/kg/h intravenously from 2 hours after the commencement of injurious ventilation (INJV + NI; n = 8). We assessed respiratory, hemodynamic and volumetric variables, including both the extravascular lung water index (EVLWI) and the pulmonary vascular permeability index (PVPI). We measured plasma nitrite/nitrate (NOx) levels and examined lung biopsies for lung injury score (LIS). Results Both the injuriously ventilated groups demonstrated a 2–3-fold rise in EVLWI and PVPI, with no significant effects of NI. In the INJV group, gas exchange deteriorated in parallel with emerging respiratory acidosis, but administration of NI antagonized the derangement of oxygenation and the respiratory acidosis significantly. NOx displayed no significant changes and NI exerted no significant effect on LIS in the INJV group. Conclusion Inhibition of nNOS improved gas exchange, but did not

  19. Intravital microscopy of subpleural alveoli via transthoracic endoscopy

    NASA Astrophysics Data System (ADS)

    Schwenninger, David; Runck, Hanna; Schumann, Stefan; Haberstroh, Jörg; Meissner, Sven; Koch, Edmund; Guttmann, Josef

    2011-04-01

    Transfer of too high mechanical energy from the ventilator to the lung's alveolar tissue is the main cause for ventilator-induced lung injury (VILI). To investigate the effects of cyclic energy transfer to the alveoli, we introduce a new method of transthoracic endoscopy that provides morphological as well as functional information about alveolar geometry and mechanics. We evaluate the new endoscopic method to continuously record images of focused subpleural alveoli. The method is evaluated by using finite element modeling techniques and by direct observation of subpleural alveoli both in isolated rat lungs as well as in intact animals (rats). The results confirm the overall low invasiveness of the endoscopic method insofar as the mechanical influences on the recorded alveoli are only marginal. It is, hence, a suited method for intravital microscopy in the rat model as well as in larger animals.

  20. Mechanical ventilation of patients with acute lung injury.

    PubMed

    Sessler, C N

    1998-10-01

    Ventilatory management of patients with acute lung injury (ALI), particularly its most severe subset, acute respiratory distress syndrome (ARDS), is complex. Newer lung protective strategies emphasize measures to enhance alveolar recruitment and avoid alveolar overdistention, thus minimizing the risk of ventilator-induced lung injury (VILI). Key components of such strategies include the use of smaller-than-conventional tidal volumes which maintain peak transpulmonary pressure below the pressure associated with overdistention, and titration of positive end-expiratory pressure to promote maximal alveolar recruitment. Novel techniques, including prone positioning, inverse ratio ventilation, tracheal gas insufflation, and high frequency ventilation, are considerations in severe ARDS. No single approach is best for all patients; adjustment of ventilatory parameters to individual characteristics, such as lung mechanics and gas exchange, is required. PMID:9891634

  1. Visual inspection with acetic acid and Lugol's iodine in cervical cancer screening at the general referral hospital Kayembe in Mbuji-Mayi, Democratic Republic of Congo

    PubMed Central

    Desire, Banza Kamba; Philippe, Cilundika Mulenga; Thierry, Kabengele; Félix, Kitenge Wa Momat; Wembodinga, Gilbert Utshudienyema; Prosper, Kakudji Luhete; Oscar, Luboya Numbi

    2016-01-01

    Introduction Cervical cancer is the leading cause of morbidity and mortality of women from cancer in the developing World. It is the primary cause of reduced life expectancy in Sub-Saharan countries such as Democratic Republic of Congo. The aim of this work was to determinate the socio-demographic profile of women with precancerous and cancerous lesions of the cervix, to determinate the frequency of VIA and VILI positive cases and to show the challenges that can be faced in managing patients with abnormalities in the city of Mbuji-Mayi in the Democratic Republic of Congo. Methods As part of its activities, the “Association de Lutte contre le Cancer du Col utérin” (ALCC) organized a community outreach followed by free voluntary testing for cervical cancer for two weeks (26thMarch to 10th April 2011) at the General Referral Hospital Kayembe in Mbuji-Mayi (Democratic Republic of Congo). Results A total of 229 women were examined. 38% of tests (VIA + VILI) were positive with 6 clinically suspected cases of invasive cancer at stage 1 (7% of cases). Nearly 70% of patients were still of childbearing age and had started their first sexual intercourse before 18 years of age and 86% of cases were multiparous. Given the material, financial and technical constraints, 75% of patients were placed in a monitoring program of 9 months to 1 year (= expectation and another test) while 11% of them were selected for a biopsy to be locally practiced and sent to the pathologist. Nearly 8% of the cases were candidates for hysterectomy. Conclusion Given the difficulties encountered and the frequency of positive tests, we recommend another study with a larger sample, improved working conditions (mainly equipment) and the association of another test such as the Human Papilloma Virus (HPV) test. PMID:27217888

  2. μ-PIV/Shadowgraphy measurements to elucidate dynamic physicochemical interactions in a multiphase model of pulmonary airway reopening

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Eiichiro

    2010-10-01

    We employ micro-particle image velocimetry (μ-PIV) and shadowgraphy to measure the ensemble-averaged fluid-phase velocity field and interfacial geometry during pulsatile bubble propagation that includes a reverse-flow phase under influence of exogenous lung surfactant (Infasurf). Disease states such as respiratory distress syndrome (RDS) are characterized by insufficient pulmonary surfactant concentrations that enhance airway occlusion and collapse. Subsequent airway reopening, driven by mechanical ventilation, may generate damaging stresses that cause ventilator-induced lung injury (VILI). It is hypothesized that reverse flow may enhance surfactant uptake and protect the lung from VILI. The microscale observations conducted in this study will provide us with a significant understanding of dynamic physicochemical interactions that can be manipulated to reduce the magnitude of this damaging mechanical stimulus during airway reopening. Bubble propagation through a liquid-occluded fused glass capillary tube is controlled by linear-motor-driven syringe pumps that provide mean and sinusoidal velocity components. A translating microscope stage mechanically subtracts the mean velocity of the bubble tip in order to hold the progressing bubble tip in the microscope field of view. To optimize the signal-to-noise ratio near the bubble tip, μ-PIV and shadow images are recorded in separate trials then combined during post-processing with help of a custom-designed micro scale marker. Non-specific binding of Infasurf proteins to the channel wall is controlled by oxidation and chemical treatment of the glass surface. The colloidal stability and dynamic/static surface properties of the Infasurf-PIV particle solution are carefully adjusted based on Langmuir trough measurements. The Finite Time Lyapunov Exponent (FTLE) is computed to provide a Lagrangian perspective for comparison with our boundary element predictions.

  3. Transversity quark distributions in a covariant quark-diquark model

    SciTech Connect

    I.C. Cloet; W. Bentz; A.W. Thomas

    2008-01-01

    Transversity quark light-cone momentum distributions are calculated for the nucleon. We utilize a modified Nambu--Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the relativistic Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquark channels are included. Particular attention is paid to comparing our results with the recent experimental extraction of the transversity distributions by Anselmino et al. We also compare our transversity results with earlier spin-independent and helicity quark distributions calculated in the same approach.

  4. The role of asymptotic freedom for the pseudocritical temperature in magnetized quark matter

    NASA Astrophysics Data System (ADS)

    Farias, R. L. S.; Gomes, K. P.; Krein, G.; Pinto, M. B.

    2015-07-01

    Motivated by discrepancies observed between lattice QCD simulations and quark models regarding the behavior of the pseudo critical temperature for chiral symmetry restoration as a function of the magnetic field B, we investigate the effects of a running the quark coupling constant G with temperature T and the magnetic field B in the context of the Nambu-Jona- Lasinio model(NJL). Our point that when asymptotic freedom, an essential feature of QCD and absent in the model, is included through a running of G with T and B results from the NJL model can be brought in qualitative agreement with lattice QCD simulations.

  5. Impact of a magnetic field on the thermodynamics of magnetized quark matter

    NASA Astrophysics Data System (ADS)

    Farias, R. L. S.; Timóteo, V. S.; Avancini, S.; Pinto, M. B.; Krein, G.

    2016-04-01

    We investigate the effect of a magnetic field on the thermodynamics of magnetized quark matter at finite temperature. By using the Nambu Jona-Lasino (NJL) model, we show that the lattice results for the quark consensate can be reproduced when the coupling constant G of the model decreases with the magnetic field and the temperature. Our results show that thermodynamic quantities and quark condensates are very sensitive to the dependence of G with the temperature, even in the absence of a magnetic field.

  6. The Roberge-Weiss phase transition and its endpoint

    NASA Astrophysics Data System (ADS)

    Kouno, Hiroaki; Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu

    2009-11-01

    The Roberge-Weiss (RW) phase transition in the imaginary chemical potential region is analyzed by the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. In the RW phase transition, the charge-conjugation symmetry is spontaneously broken, while the extended {\\mathbb Z}_{3} symmetry (the RW periodicity) is preserved. The RW transition is of second order at the endpoint. At the zero chemical potential, a crossover deconfinement transition appears as a remnant of the second-order RW phase transition at the endpoint, while the charge-conjugation symmetry is always preserved.

  7. Constantin Levaditi (1874-1953): a pioneer in Immunology and Virology.

    PubMed

    Kalantzis, George; Skiadas, Panagiotis; Lascaratos, John

    2006-08-01

    The eminent doctor Constantin Levaditi represents one of the most important researchers in the field of medicine in the 20th century. Although he was engaged in many areas of the rapidly growing field of immunology, his name is associated mainly with research in poliomyelitis. His laboratory research contributed decisively to the clarification of the epidemiology of this dreadful disease that claimed thousands of victims. Moreover, his experimental work constituted the basis for the development of the vaccine against poliomyelitis, initially in 1955 by Jonas Salk (1914-95) using inactivated virus, and then in 1960 by Albert Sabin (1906-93) who used live attenuated virus. PMID:16845465

  8. [Historical development of vaccines. Introduction: Hazards and rationality in the vaccinal approach].

    PubMed

    Moulin, A M

    1995-01-01

    The aim of this paper is to introduce the one hundred years of vaccination that has passed since Louis Pasteur first coined this generic term. According to the late Jonas Salk, vaccinology is a science encompassing all aspects of vaccine from its conception in the laboratory to its production by companies and its application and distribution in the field. In this historical survey I explore how vaccination never consisted of a simple and uniform application of a rational model, but rather diverged along various pathways, several of which were discarded in retrospect as being hazardous, and I analyse the ongoing interplay between rational and inventive thinking. PMID:8552750

  9. FDA advisory committees meet January 26 on Salk HIV-1 immunogen.

    PubMed

    1995-01-01

    Two advisory committees of the Food and Drug Administration (FDA) will meet to consider future trials of the HIV-1 immunogen developed by Dr. Jonas Salk. The Immune Response Corporation has already conducted several studies of the immunogen, and has found improvement in various immunological and other blood tests, and no adverse effects. However, the studies have not been large enough to show conclusively that the treatment has clinical benefit in delaying disease progression. The new, larger trials are intended to demonstrate a delay in disease progression and validate the use of blood-test markers of disease progression for studying an immune-based treatment. PMID:11362184

  10. Agouron and immune response to commercialize remune immune-based treatment.

    PubMed

    James, J S

    1998-06-19

    Agouron Pharmaceuticals agreed in June to collaborate with The Immune Response Corporation on the final development and marketing of an immune-based treatment for HIV. Remune, the vaccine developed by Dr. Jonas Salk, is currently in Phase III randomized trials with 2,500 patients, and the trials are expected to be completed in April 1999. Immune-based treatments have been difficult to test, as there is no surrogate marker, like viral load, to determine if the drug is working. Agouron agreed to participate in the joint venture after reviewing encouraging results from preliminary trials in which remune was taken in combination with highly active antiretroviral drugs. PMID:11365593

  11. Neutrino emission from compact stars and inhomogeneous color superconductivity

    SciTech Connect

    Anglani, Roberto; Nardulli, Giuseppe; Ruggieri, Marco; Mannarelli, Massimo

    2006-10-01

    We discuss specific heat and neutrino emissivity due to direct Urca processes for quark matter in the color superconductive Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase of quantum chromodynamics. We assume that the three light quarks u, d, s are in a color and electrically neutral state and interact by a four-fermion Nambu-Jona-Lasinio coupling. We study a LOFF state characterized by a single plane wave for each pairing. From the evaluation of neutrino emissivity and fermionic specific heat, the cooling rate of simplified models of compact stars with a quark core in the LOFF state is estimated.

  12. Magnetized color superconducting cold quark matter within the SU(2 ) f NJL model: A novel regularization scheme

    NASA Astrophysics Data System (ADS)

    Allen, P.; Grunfeld, A. G.; Scoccola, N. N.

    2015-10-01

    The influence of intense magnetic fields on the behavior of color superconducting cold quark matter is investigated using an SU(2 ) f Nambu-Jona-Lasinio-type model for which a novel regulation scheme is introduced. In such a scheme the contributions which are explicitly dependent on the magnetic field turn out to be finite and, thus, do not require to be regularized. As a result of this, nonphysical oscillations that might arise in the alternative regularization schemes previously used in the literature are naturally removed. In this way, a clearer interpretation of the physical oscillations is possible. The sensitivity of our results to the model parametrization is analyzed.

  13. Structure of compact stars in a pion superfluid phase

    NASA Astrophysics Data System (ADS)

    Mao, Shijun

    2014-06-01

    The gross structure of compact stars composed of pion superfluid quark matter is investigated in the frame of the Nambu-Jona-Lasinio model. Under the Pauli-Villars regularization scheme, the uncertainty of the thermodynamic functions for inhomogeneous states is cured, and the Larkin-Ovchinnikov-Fulde-Ferrel state that appeared in the hard cutoff scheme is removed from the phase diagram of the pion superfluid. Different from the unpaired quark matter and color superconductor, the strongly coupled pion superfluid is a possible candidate of compact stars with mass M ≃3M⊙ and radius R ≃14 km.

  14. Responses of quark condensates to the chemical potential

    NASA Astrophysics Data System (ADS)

    Miyamura, O.; Choe, S.; Liu, Y.; Takaishi, T.; Nakamura, A.

    2002-10-01

    The responses of quark condensates to the chemical potential, as a function of temperature T and chemical potential μ, are calculated within the Nambu-Jona-Lasinio (NJL) model. We compare our results with those from the recent lattice QCD simulations [QCD-TARO Collaboration, S. Choe et al., Nucl. Phys. B (Proc. Suppl.) 106, 462 (2002)]. The NJL model and lattice calculations show qualitatively similar behavior, and they will be complimentary ways to study hadrons at finite density. The behavior above Tc requires more elaborated analyses.

  15. Production of {omega}{pi}{sup 0} pairs in electron-positron annihilation

    SciTech Connect

    Arbuzov, A. B.; Kuraev, E. A.; Volkov, M. K.

    2011-04-15

    The process of electron-positron annihilation into a pair of {pi}{sup 0} and {omega} mesons is considered in the framework of the SU(2)xSU(2) Nambu-Jona-Lasinio model. Contributions of intermediate photons, {rho}(770) and {rho}{sup '}(1450) vector mesons are taken into account. It is shown that the bulk of the cross section at energies below 2 GeV is provided by the process with intermediate {rho}{sup '}(1450) state. The contribution due to single photon and {rho}(770) exchange is in agreement with the vector meson dominance model. Numerical results are compared with experimental data.

  16. Electromagnetic decays of radially excited mesons {pi}{sup 0 Prime }, {rho}{sup 0 Prime }, {omega}{sup 0 Prime }, and production of {pi}{sup 0 Prime} at lepton colliders

    SciTech Connect

    Arbuzov, A. B. Kuraev, E. A.; Volkov, M. K.

    2011-05-15

    Radiative decays {pi}{sup 0}({pi}{sup 0 Prime }) {yields} {gamma} + {gamma}, {pi}{sup 0 Prime} {yields} {rho}{sup 0}({omega}) + {gamma}, {rho}{sup 0 Prime }({omega} Prime ) {yields} {pi}{sup 0} + {gamma}, {rho}{sup 0 Prime }({omega} Prime ) {yields} {pi}{sup 0 Prime} + {gamma}, and some processes of {pi}{sup 0 Prime} production at lepton colliders are considered in the framework of the nonlocal SU(2) Multiplication-Sign SU(2) Nambu-Jona-Lasinio model. Mixing of the radially excited and the ground meson states is taken into account. Numerical results for the decay and production processes are presented.

  17. Electromagnetic triangle anomaly and neutral pion condensation in QCD vacuum

    NASA Astrophysics Data System (ADS)

    Cao, Gaoqing; Huang, Xu-Guang

    2016-06-01

    We study the QCD vacuum structure under the influence of an electromagnetic field with a nonzero second Lorentz invariant I2 = E ṡ B. We show that the presence of I2 can induce neutral pion (π0) condensation in the QCD vacuum through the electromagnetic triangle anomaly. Within the frameworks of chiral perturbation theory at leading small-momenta expansion as well as the Nambu-Jona-Lasinio model at leading 1 /Nc expansion, we quantify the dependence of the π0 condensate on I2. The stability of the π0-condensed vacuum against the Schwinger charged pair production due to electric field is also discussed.

  18. [The biologization of ethics].

    PubMed

    Moreno Lax, Alejandro

    2010-01-01

    Three ethics exist as a condition of possibility of any possible ethics, following a material and biological foundation. This content argument (not logical-formal) supposes a refutation of the naturalistic fallacy that the analytical philosophy attributes to Hume, in three areas of the ethical human experience: body, society and nature. These are: the ethics of the species [J. Habermas], the ethics of liberation [E. Dussel] and the ethics of the responsibility [H. Jonas]. This material argument is a philosophical foundation to considering for three types of applied ethics: medical bioethics, development ethics and environmental ethics. PMID:20405971

  19. Baryon octet electromagnetic form factors in a confining NJL model

    NASA Astrophysics Data System (ADS)

    Carrillo-Serrano, Manuel E.; Bentz, Wolfgang; Cloët, Ian C.; Thomas, Anthony W.

    2016-08-01

    Electromagnetic form factors of the baryon octet are studied using a Nambu-Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp < rEΣ+ and | rEn | < | rEΞ0 |, whereas the magnetic radii have a pattern largely consistent with a naive expectation based on the dressed quark masses.

  20. Determination of QCD phase diagram from the imaginary chemical potential region

    SciTech Connect

    Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu; Kouno, Hiroaki; Matsuzaki, Masayuki

    2009-05-01

    We test the reliability of the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model, comparing the model result with the lattice data at nonzero imaginary chemical potential. The PNJL model with the vector-type four-quark and scalar-type eight-quark interactions reproduces the lattice data on the pseudocritical temperatures of the deconfinement and chiral phase transitions. The QCD phase diagram in the real chemical potential region is predicted by the PNJL model. The critical end point survives, even if the vector-type four-quark interaction is taken into account.

  1. Quark and gluon condensates in isospin matter

    SciTech Connect

    He Lianyi; Jiang Yin; Zhuang Pengfei

    2009-04-15

    By applying the Hellmann-Feynman theorem to a charged pion gas, the quark and gluon condensates at low isospin density are determined by precise pion properties. At intermediate density around f{sub {pi}}{sup 2}m{sub {pi}}, from both the estimation for the dilute pion gas and the calculation with the Nambu-Jona-Lasinio model, the quark condensate is strongly and monotonously suppressed, while the gluon condensate is enhanced and can be larger than its vacuum value. This unusual behavior of the gluon condensate is universal for Bose condensed matter of mesons. Our results can be tested by lattice calculations at finite isospin density.

  2. Phase structure in a chiral model of nuclear matter

    SciTech Connect

    Phat, Tran Huu; Anh, Nguyen Tuan; Tam, Dinh Thanh

    2011-08-15

    The phase structure of symmetric nuclear matter in the extended Nambu-Jona-Lasinio (ENJL) model is studied by means of the effective potential in the one-loop approximation. It is found that chiral symmetry gets restored at high nuclear density and a typical first-order phase transition of the liquid-gas transition occurs at zero temperature, T=0, which weakens as T grows and eventually ends up with a second-order critical point at T=20 MeV. This phase transition scenario is confirmed by investigating the evolution of the effective potential versus the effective nucleon mass and the equation of state.

  3. Entanglement between the Deconfinement and the Chiral Symmetry Restoration

    SciTech Connect

    Sakai, Yuji; Sasaki, Takahiro; Yahiro, Masanobu; Kouno, Hiroaki

    2011-10-21

    We extend the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model by introducing an effective four-quark vertex depending on the Polyakov loop. The effective vertex generates entanglement interactions between the Polyakov loop and the chiral condensate. The new model is consistent with lattice QCD data at imaginary quark-number chemical potential and real and imaginary isospin chemical potentials. We investigate the influence of the entanglement interactions on the location of the critical endpoint at real quark-number chemical potential.

  4. Phase transition and critical end point driven by an external magnetic field in asymmetric quark matter

    NASA Astrophysics Data System (ADS)

    Costa, Pedro; Ferreira, Márcio; Hansen, Hubert; Menezes, Débora P.; Providência, Constança

    2014-03-01

    The location of the critical end point (CEP) in the QCD phase diagram is determined under different scenarios. The effect of strangeness, isospin/charge asymmetry and an external magnetic field is investigated. The discussion is performed within the 2+1 flavor Nambu-Jona-Lasinio model with Polyakov loop. It is shown that isospin asymmetry shifts the CEP to larger baryonic chemical potentials and smaller temperatures. At large asymmetries the CEP disappears. However, a strong enough magnetic field drives the system into a first order phase transition.

  5. Free energy of a baryon at finite temperatures and its implications to the heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Biswal, Minati; Digal, Sanatan; Saumia, P. S.

    2015-07-01

    We study the free energy per baryon using canonical formalism in the Polyakov loop Nambu-Jona-Lasinio model with imaginary chemical potential. We find that the free energy decreases rapidly with temperature around the transition temperature. This result coupled with the heavy-ion collision geometry leads to the creation of a free energy well for the baryons. We study the time evolution of this free energy well using hydrodynamic simulations and discuss the implications of this free energy well on the dynamics of the baryons.

  6. Phase diagram of the three-flavor color superconducting PNJL model

    NASA Astrophysics Data System (ADS)

    Ayriyan, Alexander; Blaschke, David; Lastowiecki, Rafal

    2016-01-01

    The phase diagram of a three-flavor Polyakov-loop Nambu-Jona-Lasinio model is analyzed for symmetric matter with a parametrization consistent with the 2 M⊙mass constraint from the pulsars PSR J1614-2230 and PSR J0348+0432. A coexistence of partial chiral symmetry restoration, diquark condensation (2SC phase) and the hadronic (confined) phase is conjectured that entails the existence of a quadruple point and is accessible by trajectories of constant entropy per baryon for heavy-ion collisions in the NICA/FAIR energy range.

  7. Two-color QCD at imaginary chemical potential and its impact on real chemical potential

    NASA Astrophysics Data System (ADS)

    Kashiwa, Kouji; Sasaki, Takahiro; Kouno, Hiroaki; Yahiro, Masanobu

    2013-01-01

    We study properties of two-color QCD at imaginary chemical potential (μ) from the viewpoint of the Roberge-Weiss periodicity, the charge conjugation, and the pseudoreality. At μ=±iπT/2, where T is temperature, the system is symmetric under the combination of the charge conjugation C and the Z2 transformation. The symmetry, called CZ2 symmetry, is preserved at lower T but spontaneously broken at higher T. The Polyakov-loop extended Nambu-Jona-Lasinio model has the same properties as two-color QCD for CZ2 symmetry and the pseudoreality. The nontrivial correlation between the chiral restoration and the deconfinement are investigated by introducing the entanglement vertex in the Polyakov-loop extended Nambu-Jona-Lasinio model. The order of CZ2 symmetry breaking at the Roberge-Weiss end point is second order when the correlation is weak, but becomes first order when the correlation is strong. We also investigate the impact of the correlation on the phase diagram at real μ.

  8. What ecologists can tell virologists.

    PubMed

    Dennehy, John J

    2014-01-01

    I pictured myself as a virus…and tried to sense what it would be like. --Jonas Salk. Ecology as a science evolved from natural history, the observational study of the interactions of plants and animals with each other and their environments. As natural history matured, it became increasingly quantitative, experimental, and taxonomically broad. Focus diversified beyond the Eukarya to include the hidden world of microbial life. Microbes, particularly viruses, were shown to exist in unfathomable numbers, affecting every living organism. Slowly viruses came to be viewed in an ecological context rather than as abstract, disease-causing agents. This shift is exemplified by an increasing tendency to refer to viruses as living organisms instead of inert particles. In recent years, researchers have recognized the critical contributions of viruses to fundamental ecological processes such as biogeochemical cycling, competition, community structuring, and horizontal gene transfer. This review describes virus ecology from a virus's perspective. If we are, like Jonas Salk, to imagine ourselves as a virus, what kind of world would we experience? PMID:24847957

  9. Quark fragmentation functions in NJL-jet model

    NASA Astrophysics Data System (ADS)

    Bentz, Wolfgang; Matevosyan, Hrayr; Thomas, Anthony

    2014-09-01

    We report on our studies of quark fragmentation functions in the Nambu-Jona-Lasinio (NJL) - jet model. The results of Monte-Carlo simulations for the fragmentation functions to mesons and nucleons, as well as to pion and kaon pairs (dihadron fragmentation functions) are presented. The important role of intermediate vector meson resonances for those semi-inclusive deep inelastic production processes is emphasized. Our studies are very relevant for the extraction of transverse momentum dependent quark distribution functions from measured scattering cross sections. We report on our studies of quark fragmentation functions in the Nambu-Jona-Lasinio (NJL) - jet model. The results of Monte-Carlo simulations for the fragmentation functions to mesons and nucleons, as well as to pion and kaon pairs (dihadron fragmentation functions) are presented. The important role of intermediate vector meson resonances for those semi-inclusive deep inelastic production processes is emphasized. Our studies are very relevant for the extraction of transverse momentum dependent quark distribution functions from measured scattering cross sections. Supported by Grant in Aid for Scientific Research, Japanese Ministry of Education, Culture, Sports, Science and Technology, Project No. 20168769.

  10. Evaluation of primary HPV-DNA testing in relation to visual inspection methods for cervical cancer screening in rural China: an epidemiologic and cost-effectiveness modelling study

    PubMed Central

    2011-01-01

    Background A new lower-cost rapid-throughput human papillomavirus (HPV) test (careHPV, Qiagen, Gaithersburg, USA) has been shown to have high sensitivity for the detection of high grade cervical intraepithelial neoplasia. Methods We assessed the outcomes and cost-effectiveness of careHPV screening in rural China, compared to visual inspection with acetic acid, when used alone (VIA) or in combination with Lugol's iodine (VIA/VILI). Using data on sexual behaviour, test accuracy, diagnostic practices and costs from studies performed in rural China, we estimated the cost-effectiveness ratio (CER) and associated lifetime outcomes for once-lifetime and twice-lifetime screening strategies, and for routine screening at 5-yearly, 10-yearly and IARC-recommended intervals. The optimal age range for once-lifetime screening was also assessed. Results For all strategies, the relative ordering of test technologies in reducing cervical cancer incidence and mortality was VIA (least effective); VIA/VILI; careHPV@1.0 pg/ml and careHPV@0.5 pg/ml (most effective). For once-lifetime strategies, maximum effectiveness was achieved if screening occurred between 35-50 years. Assuming a participation rate of ~70%, once-lifetime screening at age 35 years would reduce cancer mortality by 8% (for VIA) to 12% (for careHPV@0.5) over the long term, with a CER of US$557 (for VIA) to $959 (for careHPV@1.0) per life year saved (LYS) compared to no intervention; referenced to a 2008 GDP per capita in Shanxi Province of $2,975. Correspondingly, regular screening with an age-standardised participation rate of 62% (which has been shown to be achievable in this setting) would reduce cervical cancer mortality by 19-28% (for 10-yearly screening) to 43-54% (using IARC-recommended intervals), with corresponding CERs ranging from $665 (for 10-yearly VIA) to $2,269 (for IARC-recommended intervals using careHPV@1.0) per LYS. Conclusions This modelled analysis suggests that primary careHPV screening compares

  11. Trials and projects on cervical cancer and human papillomavirus prevention in sub-Saharan Africa.

    PubMed

    Adefuye, Peter O; Broutet, Nathalie J; de Sanjosé, Silvia; Denny, Lynette A

    2013-12-29

    Cervical cancer is the leading cause of cancer morbidity and mortality in women in sub-Saharan Africa (SSA), accounting for about 50,000 deaths annually. Until recently, cytology was the gold standard for screening and prevention of cervical cancer. This method of screening has not been successful in SSA due to a lack of human, financial and material resources and poor health care infrastructure. It is estimated that less than 5% of at risk women have ever being screened. In the past two decades alternative approaches to cytology for cervical cancer screening have been evaluated in low- and medium-income countries. Visual inspection with acetic acid (VIA) and/or Lugol's iodine (VILI) have been shown to have adequate sensitivity, although low specificity, in a number of cross-sectional research and demonstration projects. Visual inspection methods require minimal resources, are technologically accessible, and are feasible for screening for precancerous lesions. Linking screening with VIA/VILI to treatment with cryotherapy may enable screening and treatment to take place in one visit, but this is likely to result in large numbers of women being subjected to unnecessary treatment. A number of studies have shown that cryotherapy is not associated with significant side effects or complications and is well tolerated. Creating the infrastructure for screening of older women is considered desirable, despite the limitations of visual inspection methods as screening tests. Understanding the role of human papillomavirus (HPV) infection in the etiology of cervical cancer and the discovery of HPV rapid test kits, as well as the development of vaccines against the HPV oncogenic types, have created new opportunities for prevention of cervical cancer. Trials and projects have established (and are still ongoing) the feasibility of using these molecular tests for screening. The ultimate in prevention method is primary prevention, offered by the advent of prophylactic vaccines

  12. Imaging of the three-dimensional alveolar structure and the alveolar mechanics of a ventilated and perfused isolated rabbit lung with Fourier domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Popp, Alexander; Wendel, Martina; Knels, Lilla; Koch, T.; Koch, Edmund

    2006-01-01

    In this feasibility study, Fourier domain optical coherence tomography (FDOCT) is used for visualizing the 3-D structure of fixated lung parenchyma and to capture real-time cross sectional images of the subpleural alveolar mechanics in a ventilated and perfused isolated rabbit lung. The compact and modular setup of the FDOCT system allows us to image the first 500 µm of subpleural lung parenchyma with a 3-D resolution of 16×16×8 µm (in air). During mechanical ventilation, real-time cross sectional FDOCT images visualize the inflation and deflation of alveoli and alveolar sacks (acini) in successive images of end-inspiratory and end-expiratory phase. The FDOCT imaging shows the relation of local alveolar mechanics to the setting of tidal volume (VT), peak airway pressure, and positive end-expiratory pressure (PEEP). Application of PEEP leads to persistent recruitment of alveoli and acini in the end-expiratory phase, compared to ventilation without PEEP where alveolar collapse and reinflation are observed. The imaging of alveolar mechanics by FDOCT will help to determine the amount of mechanical stress put on the alveolar walls during tidal ventilation, which is a key factor in understanding the development of ventilator induced lung injury (VILI).

  13. Effect of Electrode Belt and Body Positions on Regional Pulmonary Ventilation- and Perfusion-Related Impedance Changes Measured by Electric Impedance Tomography.

    PubMed

    Ericsson, Elin; Tesselaar, Erik; Sjöberg, Folke

    2016-01-01

    Ventilator-induced or ventilator-associated lung injury (VILI/VALI) is common and there is an increasing demand for a tool that can optimize ventilator settings. Electrical impedance tomography (EIT) can detect changes in impedance caused by pulmonary ventilation and perfusion, but the effect of changes in the position of the body and in the placing of the electrode belt on the impedance signal have not to our knowledge been thoroughly evaluated. We therefore studied ventilation-related and perfusion-related changes in impedance during spontaneous breathing in 10 healthy subjects in five different body positions and with the electrode belt placed at three different thoracic positions using a 32-electrode EIT system. We found differences between regions of interest that could be attributed to changes in the position of the body, and differences in impedance amplitudes when the position of the electrode belt was changed. Ventilation-related changes in impedance could therefore be related to changes in the position of both the body and the electrode belt. Perfusion-related changes in impedance were probably related to the interference of major vessels. While these findings give us some insight into the sources of variation in impedance signals as a result of changes in the positions of both the body and the electrode belt, further studies on the origin of the perfusion-related impedance signal are needed to improve EIT further as a tool for the monitoring of pulmonary ventilation and perfusion. PMID:27253433

  14. Syntheses of novel protein products (milkglyde, saliglyde, and soyglyde) from vegetable epoxy oils and gliadin.

    PubMed

    Harry-O'kuru, Rogers E; Mohamed, Abdellatif; Gordon, Sherald H; Xu, James

    2012-02-22

    The aqueous alcohol-soluble fraction of wheat gluten is gliadin. This component has been implicated as the causative principle in celiac disease, which is a physiological condition experienced by some infants and adults. The outcome of the ingestion of whole wheat products by susceptible individuals is malabsorption of nutrients resulting from loss of intestinal vili, the nutrient absorption regions of the digestive system. This leads to incessant diarrhea and weight loss in these individuals. Only recently has this health condition been properly recognized and accurately diagnosed in this country. The culprit gliadin is characterized by preponderant glutamine side-chain residues on the protein surface. Gliadin is commercially available as a wheat gluten extract, and in our search for new biobased and environmentally friendly products from renewable agricultural substrates, we have exploited the availability of the glutamine residues of gliadin as synthons to produce novel elastomeric nonfood products dubbed "milkglyde", "saliglyde", and soyglyde from milkweed, salicornia and soybean oils. The reaction is an amidolysis of the oxirane groups of derivatized milkweed, salicornia, and soybean oils under neat reaction conditions with the primary amide functionalties of glutamine to give the corresponding amidohyroxy gliadinyl triglycerides, respectively. The differential scanning calorimetry, thermogravimetric analyses, and rheological data from a study of these products indicate properties similar to those of synthetic rubber. PMID:22250811

  15. Imaging of the three-dimensional alveolar structure and the alveolar mechanics of a ventilated and perfused isolated rabbit lung with Fourier domain optical coherence tomography.

    PubMed

    Popp, Alexander; Wendel, Martina; Knels, Lilla; Koch, Thea; Koch, Edmund

    2006-01-01

    In this feasibility study, Fourier domain optical coherence tomography (FDOCT) is used for visualizing the 3-D structure of fixated lung parenchyma and to capture real-time cross sectional images of the subpleural alveolar mechanics in a ventilated and perfused isolated rabbit lung. The compact and modular setup of the FDOCT system allows us to image the first 500 microm of subpleural lung parenchyma with a 3-D resolution of 16 x 16 x 8 microm (in air). During mechanical ventilation, real-time cross sectional FDOCT images visualize the inflation and deflation of alveoli and alveolar sacks (acini) in successive images of end-inspiratory and end-expiratory phase. The FDOCT imaging shows the relation of local alveolar mechanics to the setting of tidal volume (VT), peak airway pressure, and positive end-expiratory pressure (PEEP). Application of PEEP leads to persistent recruitment of alveoli and acini in the end-expiratory phase, compared to ventilation without PEEP where alveolar collapse and reinflation are observed. The imaging of alveolar mechanics by FDOCT will help to determine the amount of mechanical stress put on the alveolar walls during tidal ventilation, which is a key factor in understanding the development of ventilator induced lung injury (VILI). PMID:16526892

  16. [Home mechanical ventilation-tracheostomy ventilation, for the long-term and variation].

    PubMed

    Yamamoto, Makoto

    2006-12-01

    We experienced long-term ventilation for 30 patients mostly with amyotrophic lateral sclerosis (ALS). For long-term ventilation by tracheostomy positive pressure ventilation (TPPV), we must set tidal volume (TV) over 600 ml, because setting 400 ml as TV usually applied in Japan, often develops atelectasis which causes frequent or serious pneumonia. To avoid both the elevation of airway pressure and hyper ventilation, the following intervals are needed: 10 times/min for breathing frequency and 2 seconds for exhaling time. In the cases with ventilator induced lung injury (VILI), it is necessary to lower the TV and to treat with steroid pulse therapy. In the transitional stage from non-invasive positive pressure ventilation (NPPV) to TPPV, we conduct tracheostomy for suction of the sputum. In that stage, by using a cuffless tracheal canule, we can continue NPPV. As another method in that stage, we recommend biphasic management by NPPV at daytime and TPPV at nighttime with a bi-level ventilator. This method can provide certain ventilation also during sleep. When the respiratory failure proceeds further, we manage the ventilation with a bi-level ventilator on TPPV, because a bi-level ventilator is also good adapting to assist spontaneous breathing in that stage. And if the patient does not have bulbar paralysis, the patient can utter by air leakage with using bi-level ventilator and flattening the cuff of the tracheal canule. PMID:17469348

  17. Optical coherence tomography and confocal fluorescence microscopy as a combined method for studying morphological changes in lung dynamics

    NASA Astrophysics Data System (ADS)

    Gaertner, Maria; Cimalla, Peter; Knels, Lilla; Meissner, Sven; Schnabel, Christian; Kuebler, Wolfgang M.; Koch, Edmund

    2011-03-01

    Acute lung injury (ALI) is a severe pulmonary disease leading to hypoxemia accompanied by a reduced compliance and partial edema of the lung. Most of the patients have to be ventilated to compensate for the lack of oxygen. The treatment is strongly connected with ventilator induced lung injury (VILI), which is believed to introduce further stress to the lung and changes in its elastic performance. A thorough understanding of the organs micro-structure is crucial to gain more insight into the course of the disease. Due to backscattering of near-infrared light, detailed description of lung morphology can be obtained using optical coherence tomography (OCT), a non-invasive, non-contact, high resolution and fast three-dimensional imaging technique. One of its drawbacks lies in the non-specificity of light distribution in relation to defined substances, like elastic biomolecules. Using fluorescence detection, these chemical components can be visualized by introducing specifically binding fluorophores. This study presents a combined setup for studying alveolar compliance depending on volume changes and elastic fiber distributions. Simultaneously acquired OCT and confocal fluorescence images allow an entire view into morphological rearrangements during ventilation for an ex vivo mouse model using continuous pulmonary airway pressure at different values.

  18. Effect of Electrode Belt and Body Positions on Regional Pulmonary Ventilation- and Perfusion-Related Impedance Changes Measured by Electric Impedance Tomography

    PubMed Central

    Ericsson, Elin; Tesselaar, Erik; Sjöberg, Folke

    2016-01-01

    Ventilator-induced or ventilator-associated lung injury (VILI/VALI) is common and there is an increasing demand for a tool that can optimize ventilator settings. Electrical impedance tomography (EIT) can detect changes in impedance caused by pulmonary ventilation and perfusion, but the effect of changes in the position of the body and in the placing of the electrode belt on the impedance signal have not to our knowledge been thoroughly evaluated. We therefore studied ventilation-related and perfusion-related changes in impedance during spontaneous breathing in 10 healthy subjects in five different body positions and with the electrode belt placed at three different thoracic positions using a 32-electrode EIT system. We found differences between regions of interest that could be attributed to changes in the position of the body, and differences in impedance amplitudes when the position of the electrode belt was changed. Ventilation-related changes in impedance could therefore be related to changes in the position of both the body and the electrode belt. Perfusion-related changes in impedance were probably related to the interference of major vessels. While these findings give us some insight into the sources of variation in impedance signals as a result of changes in the positions of both the body and the electrode belt, further studies on the origin of the perfusion-related impedance signal are needed to improve EIT further as a tool for the monitoring of pulmonary ventilation and perfusion. PMID:27253433

  19. Force control of endothelium permeability in mechanically stressed pulmonary micro-vascular endothelial cells.

    PubMed

    Wang, Bin; Caluch, Adam; Fodil, Redouane; Féréol, Sophie; Zadigue, Patricia; Pelle, Gabriel; Louis, Bruno; Isabey, Daniel

    2012-01-01

    Mechanical factors play a key role in the pathogenesis of Acute Respiratory Distress Syndrome (ARDS) and Ventilator-Induced Lung Injury (VILI) as contributing to alveolo-capillary barrier dysfunction. This study aims at elucidating the role of the cytoskeleton (CSK) and cell-matrix adhesion system in the stressed endothelium and more precisely in the loss of integrity of the endothelial barrier. We purposely develop a cellular model made of a monolayer of confluent Human Pulmonary Microvascular Endothelial Cells (HPMVECs) whose cytoskeleton (CSK) is directly exposed to sustained cyclic mechanical stress for 1 and 2 h. We used RGD-coated ferromagnetic beads and measured permeability before and after stress application. We find that endothelial permeability increases in the stressed endothelium, hence reflecting a loss of integrity. Structural and mechanical results suggest that this endothelial barrier alteration would be due to physically-founded discrepancies in latero-basal reinforcement of adhesion sites in response to the global increase in CSK stiffness or centripetal intracellular forces. Basal reinforcement of adhesion is presently evidenced by the marked redistribution of αvβ3 integrin with cluster formation in the stressed endothelium. PMID:22766716

  20. The effects on chicks of dietary fibre from different sources: a growth factor in wheat bran.

    PubMed

    Hegde, S N; Rolls, B A; Turvey, A; Coates, M E

    1978-07-01

    1. Groups of chicks were given a low-residue diet with or without supplements of dietary fibre in the form of wheat bran, wheat straw or bagasse. Growth and food conversion efficiency (g weight gained/g food eaten; FCE) during the first 4 weeks of life were measured. 2. In every one of seven experiments supplementation of the diet with 100 g wheat bran/kg resulted in improved growth, and in three experiments FCE was also increased. 3. Supplementation with coarsely-milled wheat straw to provide an amount of unavailable carbohydrate equivalent to that in the bran diet resulted in poorer growth; finely-milled wheat straw had little effect on growth. 4. The growth-promoting effect of bran was destroyed by sterilization with heat or gamma-radiation. 5. In some experiments weights, lengths and volumes of small intestines were measured. Differences in intestinal dimensions between birds given the diet with and without fibre were not consistent, nor were they correlated with growth rate or FCE. 6. Histometric observations on small intestines from a few birds indicated that those given coarse wheat straw had longer vili and thicker muscularis layers, and the caecal tonsils had a greater area of lymphoid tissue and more follicles. PMID:566554

  1. [Ventilator-associated pneumonia and other infections].

    PubMed

    Bobik, Piotr; Siemiątkowski, Andrzej

    2014-01-01

    One of the fundamental elements of therapy in patients hospitalised in the Intensive Care Unit (ICU) is mechanical ventilation (MV). MV enables sufficient gas exchange in patients with severe respiratory insufficiency, thus preserving the proper functioning of organs and systems. However, clinical and experimental studies show that mechanical ventilation may cause severe complications, e.g. lung injury (VALI, VILI), systemic inflammatory response syndrome (SIRS), and, on rare occasions, multiple organ failure (MOF). Mechanical ventilation and especially endotracheal intubation are associated also with higher risk of infectious complications of the respiratory system: ventilator-associated respiratory infection (VARI) and ventilator-associated pneumonia (VAP). The complications of the MV listed above have a significant influence on the length of treatment and also on the increase of the costs of therapy and mortality of patients who stay in an ICU. These negative effects of supported breathing are the reasons for intensive research to find new biological markers of inflammation and lung injury, more sensitive and specific diagnostic instruments, more effective methods of therapy, and programs of prevention. The purpose of this article is the presentation of current knowledge concerning VAP-related infections, to allow pulmonologists and general practitioners to become more familiar with the problem. Basic and the most important data concerning the definition, epidemiology, pathophysiology, microbiology, diagnostics, treatment, and prevention of VAP have been included. Additionally, ventilator-associated tracheobronchitis (VAT) was discussed. PMID:25133817

  2. [What Should We Know about Respiratory Physiology for the Optimal Anesthesia Management?].

    PubMed

    Ochiai, Ryoichi

    2016-05-01

    Gas exchange in the lungs is dependent on the balance between ventilation and pulmonary perfusion, and such balance could be modified and affected by various factors, including gravity, body position, physical property of the lung, and neurological as well as humoral factors. Oxygenation is the process where the oxygen molecule moves from alveoli to the blood plasma, and this process is highly dependent on the diffusion capacity. Although the oxygen partial pressure in the blood plasma at alveoli rises rapidly because of its very low solubility, hemoglobin is essential to maintain adequate oxygen content in the whole blood. When a part of the lung has atelectasis, pulmonary shunt and desaturation of arterial blood ensue. For the optimal patient care, atelectasis and pulmonary shunt should be taken care of well with thorough monitoring. Ventilation is the process where carbon dioxide (CO2) moves from blood plasma to alveoli, and can eliminate CO2, produced by metabolism. The understanding of ventilator-induced lung injury (VILI) during acute respiratory failure leads us to ventilate the lungs in less harmful way, with lung protective ventilation, and the most important factor is driving pressure (inspiratory plateau pressure-PEEP). When the ventilator setting should be adjusted in order to maintain adequate ventilation, the respiratory frequency is essential to adjust alveolar ventilation without affecting driving pressure. PMID:27319088

  3. Mitochondrial Targeted Endonuclease III DNA Repair Enzyme Protects against Ventilator Induced Lung Injury in Mice.

    PubMed

    Hashizume, Masahiro; Mouner, Marc; Chouteau, Joshua M; Gorodnya, Olena M; Ruchko, Mykhaylo V; Wilson, Glenn L; Gillespie, Mark N; Parker, James C

    2014-01-01

    The mitochondrial targeted DNA repair enzyme, 8-oxoguanine DNA glycosylase 1, was previously reported to protect against mitochondrial DNA (mtDNA) damage and ventilator induced lung injury (VILI). In the present study we determined whether mitochondrial targeted endonuclease III (EndoIII) which cleaves oxidized pyrimidines rather than purines from damaged DNA would also protect the lung. Minimal injury from 1 h ventilation at 40 cmH2O peak inflation pressure (PIP) was reversed by EndoIII pretreatment. Moderate lung injury due to ventilation for 2 h at 40 cmH2O PIP produced a 25-fold increase in total extravascular albumin space, a 60% increase in W/D weight ratio, and marked increases in MIP-2 and IL-6. Oxidative mtDNA damage and decreases in the total tissue glutathione (GSH) and the GSH/GSSH ratio also occurred. All of these indices of injury were attenuated by mitochondrial targeted EndoIII. Massive lung injury caused by 2 h ventilation at 50 cmH2O PIP was not attenuated by EndoIII pretreatment, but all untreated mice died prior to completing the two hour ventilation protocol, whereas all EndoIII-treated mice lived for the duration of ventilation. Thus, mitochondrial targeted DNA repair enzymes were protective against mild and moderate lung damage and they enhanced survival in the most severely injured group. PMID:25153040

  4. Saikosaponin-d attenuates ventilator-induced lung injury in rats

    PubMed Central

    Wang, Hong-Wei; Liu, Ming; Zhong, Tai-Di; Fang, Xiang-Ming

    2015-01-01

    Saikosaponin-d is one of the main bioactive components in the traditional Chinese medicine Bupleurum falcatum L and possesses anti-inflammatory and immune-modulatory properties. The current study aimed to investigate the protective effects of saikosaponin-d on ventilator-induced lung injury (VILI) in rats. We found that saikosaponin-d treatment significantly attenuated the pathological changes of lungs induced by mechanical ventilation. Administration of saikosaponin-d reduced the pulmonary neutrophil infiltration as well as the MPO concentrations. Saikosaponin-d also decreased the expression of pro-inflammatory cytokines including MIP-2, IL-6 and TNF-α. Meanwhile, the expression of anti-inflammatory mediators, such as TGF-β1 and IL-10, was obviously elevated after saikosaponin-d administration. Saikosaponin-d remarkably reduced the oxidative stress and apoptosis rate in lung tissues. On the molecular level, saikosaponin-d treatment obviously downregulated the expression of caspases-3 and the pro-apoptotic protein bax, and promoted the expression level of anti-apoptotic protein bcl-2. Collectively, our study demonstrated that saikosaponin-d may attenuate ventilator induced lung injury through inhibition of inflammatory responses, oxidative stress and apoptosis. PMID:26628997

  5. Particle formation and ordering in strongly correlated fermionic systems: Solving a model of quantum chromodynamics

    NASA Astrophysics Data System (ADS)

    Azaria, P.; Konik, R. M.; Lecheminant, P.; Pálmai, T.; Takács, G.; Tsvelik, A. M.

    2016-08-01

    In this paper we study a (1 +1 )-dimensional version of the famous Nambu-Jona-Lasinio model of quantum chromodynamics (QCD2) both at zero and at finite baryon density. We use nonperturbative techniques (non-Abelian bosonization and the truncated conformal spectrum approach). When the baryon chemical potential, μ , is zero, we describe the formation of fermion three-quark (nucleons and Δ baryons) and boson (two-quark mesons, six-quark deuterons) bound states. We also study at μ =0 the formation of a topologically nontrivial phase. When the chemical potential exceeds the critical value and a finite baryon density appears, the model has a rich phase diagram which includes phases with a density wave and superfluid quasi-long-range (QLR) order, as well as a phase of a baryon Tomonaga-Luttinger liquid (strange metal). The QLR order results in either a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).

  6. QCD relics in the present-day Universe?

    SciTech Connect

    Ribeiro, J. E. F. T.; Antonov, D.; Nefediev, A. V.

    2011-05-23

    A possibility is suggested for the formation in the Universe of domains occupied by coherent-like states of strongly correlated quark-antiquark pairs. Only domains of the radius larger than 5 fm had a chance to survive over the entire history of the Universe, while the requirement of stability against the gravitational collapse restricts the maximum domain's radius to 14 km. Within the Generalised Nambu-Jona-Lasinio model, an exponential suppression with the domain's volume is found for the overlap between the macroscopic ground-state wavefunction of the quark-antiquark pairs and the QCD vacuum. This finding supports, at the microscopic level, the above arguments in favour of the stability of the domains.

  7. EMC and polarized EMC effects in Nuclei

    SciTech Connect

    Ian Cloet; Wolfgang Bentz; Anthony Thomas

    2006-05-23

    We determine nuclear structure functions and quark distributions for {sup 7}Li, {sup 11}B, {sup 15}N and {sup 27}Al. For the nucleon bound state we solve the covariant quark-diquark equations in a confining Nambu--Jona-Lasinio model, which yields excellent results for the free nucleon structure functions. The nucleus is described using a relativistic shell model, including mean scalar and vector fields that couple to the quarks in the nucleon. The nuclear structure functions are then obtained as a convolution of the structure function of the bound nucleon with the light-cone nucleon distributions. We find that we are readily able to reproduce the EMC effect in finite nuclei and confirm earlier nuclear matter studies that found a large polarized EMC effect.

  8. Probing the QCD vacuum with an Abelian chromomagnetic field: A study within an effective model

    SciTech Connect

    Campanelli, L.; Ruggieri, M.

    2009-08-01

    We study the response of the QCD vacuum to an external Abelian chromomagnetic field in the framework of a nonlocal Nambu-Jona-Lasinio model with the Polyakov loop. We use the lattice results on the deconfinement temperature of the pure gauge theory to compute the same quantity in the presence of dynamical quarks. We find a linear relationship between the deconfinement temperature with quarks and the squared root of the applied field strength, gH, in qualitative (and to some extent also quantitative) agreement with existing lattice calculations. On the other hand, we find a discrepancy on the approximate chiral symmetry restoration: while lattice results suggest the deconfinement and the chiral restoration remain linked even at a nonzero value of gH, our results are consistent with a scenario in which the two transitions are separated as gH is increased.

  9. Low-energy phenomenology of scalarless standard-model extensions with high-energy Lorentz violation

    NASA Astrophysics Data System (ADS)

    Anselmi, Damiano; Ciuffoli, Emilio

    2011-03-01

    We consider renormalizable standard model extensions that violate Lorentz symmetry at high energies, but preserve CPT, and do not contain elementary scalar fields. A Nambu-Jona-Lasinio mechanism gives masses to fermions and gauge bosons and generates composite Higgs fields at low energies. We study the effective potential at the leading order of the large-Nc expansion, prove that there exists a broken phase, and study the phase space. In general, the minimum may break invariance under boosts, rotations, and CPT, but we give evidence that there exists a Lorentz invariant phase. We study the spectrum of composite bosons and the low-energy theory in the Lorentz phase. Our approach predicts relations among the parameters of the low-energy theory. We find that such relations are compatible with the experimental data within theoretical errors. We also study the mixing among generations, the emergence of the CKM matrix, and neutrino oscillations.

  10. Importance of imaginary chemical potential for determination of QCD phase diagram

    NASA Astrophysics Data System (ADS)

    Kashiwa, Kouji; Kouno, Hiroaki; Sakai, Yuji; Yahiro, Masanobu

    2009-10-01

    Lattice QCD (LQCD) calculations have the well-known sign problem at finite real chemical potential. One approach to circumvent the problem is the analytic continuation of LQCD data to real chemical potential from imaginary one. This approach, however, has some problems in moderate real chemical potential region. Therefore, we propose the new approach, Imaginary chemical potential matching approach, to quantitatively determine the QCD phase diagram by using a phenomenological model that reproduce LQCD data at imaginary chemical potential. In this approach, we fit the model parameter by LQCD data at imaginary chemical potential. At the imaginary chemical potential, the QCD partition function has the special periodicity called Roberge-Weiss (RW) periodicity. Therefore, an adopted model must have the RW periodicity. We reveal the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model has the RW periodicity. Moreover, we investigate the meson mass behavior and show that meson mass is useful for fitting the model parameters at imaginary chemical potential.

  11. Vector-type four-quark interaction and its impact on QCD phase structure

    NASA Astrophysics Data System (ADS)

    Sakai, Yuji; Kashiwa, Kouji; Kouno, Hiroaki; Matsuzaki, Masayuki; Yahiro, Masanobu

    2008-10-01

    Effects of the vector-type four-quark interaction on QCD phase structure are investigated in the imaginary chemical potential (μ) region, by using the Polyakov-loop extended Nambu-Jona-Lasinio model with the extended Z3 symmetry. We clarify analytically the Roberge-Weiss periodicity and symmetry properties of various quantities under the existence of a vector-type four-quark interaction. In the imaginary μ region, the chiral condensate and the quark-number density are sensitive to the strength of the interaction. Based on this result, we propose a possibility to determine the strength of the vector-type interaction, which largely affects QCD phase structure in the real μ region, by comparing the results of lattice simulations and effective model calculations in the imaginary μ region.

  12. Phase diagram in the imaginary chemical potential region and extended Z3 symmetry

    NASA Astrophysics Data System (ADS)

    Sakai, Yuji; Kashiwa, Kouji; Kouno, Hiroaki; Yahiro, Masanobu

    2008-08-01

    Phase transitions in the imaginary chemical potential region are studied by the Polyakov-loop extended Nambu Jona-Lasinio model that possesses the extended Z3 symmetry. The extended-Z3 invariant quantities such as the partition function, the chiral condensate, and the modified Polyakov loop have the Roberge-Weiss (RW) periodicity. There appear four types of phase transitions: deconfinement, chiral, Polyakov-loop RW, and chiral RW transitions. The orders of the chiral and deconfinement transitions depend on the presence or absence of current quark mass, but those of the Polyakov-loop RW and chiral RW transitions do not. The scalar-type, eight-quark interaction newly added in the model makes the chiral transition line shift to the vicinity of the deconfinement transition line.

  13. Spontaneous parity and charge-conjugation violations at real isospin and imaginary baryon chemical potentials

    NASA Astrophysics Data System (ADS)

    Kouno, Hiroaki; Kishikawa, Mizuho; Sasaki, Takahiro; Sakai, Yuji; Yahiro, Masanobu

    2012-01-01

    The phase structure of two-flavor QCD is investigated at real isospin and imaginary quark chemical potentials by using the Polyakov-loop extended Nambu-Jona-Lasinio model. In the region, parity symmetry is spontaneously broken by the pion-superfluidity phase transition, whereas charge-conjugation symmetry is spontaneously violated by the Roberge-Weiss transition. The chiral (deconfinement) crossover at zero isospin and quark chemical potentials is a remnant of the parity (charge-conjugation) violation. The interplay between the parity and charge-conjugation violations are analyzed, and it is investigated how the interplay is related to the correlation between the chiral and deconfinement crossovers at zero isospin and quark chemical potentials.

  14. Meson mass at real and imaginary chemical potentials

    NASA Astrophysics Data System (ADS)

    Kashiwa, Kouji; Matsuzaki, Masayuki; Kouno, Hiroaki; Sakai, Yuji; Yahiro, Masanobu

    2009-04-01

    Chemical-potential dependence of pi and sigma meson masses is analyzed at both real and imaginary chemical potentials, μR and μI, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model that possesses both the extended Z3 symmetry and chiral symmetry. In the μI region, the meson masses have the Roberge-Weiss periodicity. The μI dependence of the meson masses becomes stronger as temperature increases. We argue that meson masses and physical quantities in the μR region will be determined from lattice QCD data on meson masses in the μI region by using the PNJL model, if the data are measured in the future.

  15. Current status of poliovirus infections.

    PubMed Central

    Melnick, J L

    1996-01-01

    Two scientists who played leading roles in the conquest of poliomyelitis died recently. In 1954, Jonas Salk provided the first licensed polio vaccine, the formalin (and heat)-inactivated virus. Albert Sabin gave us the attenuated live virus vaccine, which was licensed in 1962. This paper takes the reader through the history of the disease, including its pathogenesis, epidemiology, vaccines, and future directions. The emphasis is on vaccines, for it seems that with proper vaccination the number of new cases is falling dramatically. It is hoped that by the year 2000, we will accomplish the goal of the World Health Organization of "a world without polio." Then, because there is no animal reservoir, we can seriously discuss when and how to eliminate the need for vaccination and ultimately destroy our stocks of poliovirus. PMID:8809461

  16. Finite temperature quark matter under strong magnetic fields

    SciTech Connect

    Avancini, S. S.; Menezes, D. P.; Providencia, C.

    2011-06-15

    In this paper, we use the mean-field approximation to investigate quark matter described by both SU(2) and SU(3) versions of the Nambu-Jona-Lasinio model at temperatures below 150 MeV and subject to a strong magnetic field. This kind of matter is possibly present in the early stages of heavy-ion collisions and in the interior of protoneutron stars. We have studied symmetric and asymmetric quark matter. The effect of the magnetic field on the effective quark masses and chemical potentials is only felt for quite strong magnetic fields, above 5x10{sup 18} G, with larger effects for the lower densities. Spin polarizations are more sensitive to weaker magnetic fields and are larger for lower temperatures and lower densities. Temperature tends to wash out the magnetic field effects.

  17. Salk's HIV immunogen: an immune-based therapy in human trials since 1988.

    PubMed

    Jonas Salk, the developer of the first polio vaccine, has created a therapeutic vaccine for HIV which helps the immune system fight disease progression. Salk uses inactivated HIV-1 virus combined with Incomplete Freund's Adjuvant (IFA) in the vaccine preparation. The resulting HIV-1 immunogen was first studied in 1987, and since then, 235 seropositive individuals have received inoculations without serious adverse effects. Data from the first 25 subjects indicate that immunization with the HIV-1 immunogen results in improvement of cell-mediated response against the virus, a slower increase in the amount of virus present, and a reduced rate of clinical progression. Subsequent studies also show that higher doses of immunogen may produce stronger cell-mediated responses and high HIV-DTH (delayed-type hypersensitivity responsiveness immunogen) is associated with better outcome. Additional trials of HIV-1 immunogen are awaiting Food and Drug Administration approval. PMID:11362152

  18. Remune trial will stop; new trials planned.

    PubMed

    James, J S

    1999-05-21

    A clinical trial using remune, the anti-HIV vaccine developed by the late Dr. Jonas Salk, has been ended. The study is a clinical-endpoint trial which looks for statistically significant differences in AIDS sickness or death between patients who add remune to their treatment regimens versus those who use a placebo. Agouron Pharmaceuticals and the Immune Response Corporation who were conducting the trial announced their decision to stop it after an analysis by the Data Safety Monitoring Board. No differences in clinical endpoints were found and it was projected that continuing the trial would likely not find any. The companies are now planning two new Phase III trials using viral load testing rather than clinical endpoints as study criteria. PMID:11366461

  19. Current status of poliovirus infections.

    PubMed

    Melnick, J L

    1996-07-01

    Two scientists who played leading roles in the conquest of poliomyelitis died recently. In 1954, Jonas Salk provided the first licensed polio vaccine, the formalin (and heat)-inactivated virus. Albert Sabin gave us the attenuated live virus vaccine, which was licensed in 1962. This paper takes the reader through the history of the disease, including its pathogenesis, epidemiology, vaccines, and future directions. The emphasis is on vaccines, for it seems that with proper vaccination the number of new cases is falling dramatically. It is hoped that by the year 2000, we will accomplish the goal of the World Health Organization of "a world without polio." Then, because there is no animal reservoir, we can seriously discuss when and how to eliminate the need for vaccination and ultimately destroy our stocks of poliovirus. PMID:8809461

  20. The impact of cognitive strategy instruction on deaf learners: an international comparative study.

    PubMed

    Martin, D S; Craft, A; Sheng, Z N

    2001-10-01

    Teacher cohorts in England and China received special training in techniques for teaching higher-level critical and creative cognitive strategies to deaf learners. Both cohorts implemented the strategies in the classroom at least twice weekly for 6 months. Measures included Raven's Standard Progressive Matrices (1959), a systematic observation checklist for cognitive behaviors (Martin & Craft, 1998), and critical and creative problem situations to which students had to respond. Results were compared with those from a study of similar learners in the United States (Martin & Jonas, 1985), and little difference was found. Students in all three countries improved in reasoning, devising real-world problem solutions involving critical thinking (but not creative thinking), using cognitive vocabulary in the classroom, and expressing others' viewpoints. Postintervention focus groups showed teachers in China used a more invariant sequence in teaching the cognitive strategies, but teachers in all three countries experienced similar expansion in cognitive terminology and self-perceptions as teachers of problem solving. PMID:11816861

  1. Gravitational catalysis of chiral and color symmetry breaking of quark matter in hyperbolic space

    SciTech Connect

    Ebert, D.; Tyukov, A. V.; Zhukovsky, V. Ch.

    2009-10-15

    We study the dynamical breaking of chiral and color symmetries of dense quark matter in the ultrastatic hyperbolic spacetime R x H{sup 3} in the framework of an extended Nambu-Jona-Lasinio model. On the basis of analytical expressions for chiral and color condensates as functions of curvature and temperature, the phenomenon of dimensional reduction and gravitational catalysis of symmetry breaking in strong gravitational field is demonstrated in the regime of weak coupling constants. In the case of strong couplings it is shown that curvature leads to small corrections to the flat-space values of condensate and thus enhances the symmetry breaking effects. Finally, using numerical calculations phase transitions under the influence of chemical potential and negative curvature are considered and the phase portrait of the system is constructed.

  2. Phase diagram of hot magnetized two-flavor color-superconducting quark matter

    SciTech Connect

    Fayazbakhsh, Sh.; Sadooghi, N.

    2011-01-15

    A two-flavor color-superconducting Nambu-Jona-Lasinio model is introduced at finite temperature T, chemical potential {mu}, and in the presence of a constant magnetic field e-tildeB. The effect of (T,{mu},e-tildeB) on the formation of chiral- and color-symmetry-breaking condensates is studied. The complete phase portrait of the model in T-{mu}, {mu}-e-tildeB, and T-e-tildeB phase spaces for various fixed e-tildeB, T, and {mu} is explored. A threshold magnetic field e-tildeB{sub t}{approx_equal}0.5 GeV{sup 2} is found, above which the dynamics of the system are solely dominated by the lowest Landau level, and the effects of T and {mu} are partly compensated by e-tildeB.

  3. The equation of state of dense matter: from nuclear collisions to neutron stars

    NASA Astrophysics Data System (ADS)

    Burgio, G. F.

    2008-01-01

    The equation of state (EoS) of dense matter represents a central issue in the study of compact astrophysical objects and heavy ion reactions at intermediate and relativistic energies. We have derived a nuclear EoS with nucleons and hyperons within the Brueckner Hartree Fock approach, and joined it with quark matter EoS. For that, we have employed the MIT bag model, as well as the Nambu Jona-Lasinio and the color dielectric models, and found that the NS maximum masses are not larger than 1.7 solar masses. A comparison with available data supports the idea that dense matter EoS should be soft at low density and quite stiff at high density.

  4. Hadronic molecules with a D ¯ meson in a medium

    NASA Astrophysics Data System (ADS)

    Caramés, T. F.; Fontoura, C. E.; Krein, G.; Tsushima, K.; Vijande, J.; Valcarce, A.

    2016-08-01

    We study the effect of a hot and dense medium on the binding energy of hadronic molecules with open-charm mesons. We focus on a recent chiral quark-model-based prediction of a molecular state in the N D ¯ system. We analyze how the two-body thresholds and the hadron-hadron interactions are modified when quark and meson masses and quark-meson couplings change in a function of the temperature and baryon density according to predictions of the Nambu-Jona-Lasinio model. We find that in some cases the molecular binding is enhanced in medium as compared to their free-space binding. We discuss the consequences of our findings for the search for exotic hadrons in high-energy heavy-ion collisions as well as in the forthcoming facilities FAIR or J-PARC.

  5. Twisted kinks, Dirac transparent systems, and Darboux transformations

    NASA Astrophysics Data System (ADS)

    Correa, F.; Jakubský, V.

    2014-12-01

    Darboux transformations are employed in construction and analysis of Dirac Hamiltonians with pseudoscalar potentials. By this method, we build a four-parameter class of reflectionless systems. Their potentials correspond to the composition of complex kinks, also known as twisted kinks, that play an important role in the 1 +1 Gross-Neveu and Nambu-Jona-Lasinio field theories. The twisted kinks turn out to be multisolitonic solutions of the integrable Ablowitz-Kaup-Newell-Segur hierarchy. Consequently, all the spectral properties of the Dirac reflectionless systems are reflected in a nontrivial conserved quantity, which can be expressed in a simple way in terms of Darboux transformations. We show that the four-parameter pseudoscalar systems reduce to well-known models for specific choices of the parameters. An associated class of transparent nonrelativistic models described by a matrix Schrödinger Hamiltonian is studied and the rich algebraic structure of their integrals of motion is discussed.

  6. How the Polyakov loop and the regularization affect strangeness and restoration of symmetries at finite T

    SciTech Connect

    Ruivo, M. C.; Costa, P.; Sousa, C. A. de; Hansen, H.

    2010-08-05

    The effects of the Polyakov loop and of a regularization procedure that allows the presence of high momentum quark states at finite temperature is investigated within the Polyakov-loop extended Nambu-Jona-Lasinio model. The characteristic temperatures, as well as the behavior of observables that signal deconfinement and restoration of chiral and axial symmetries, are analyzed, paying special attention to the behavior of strangeness degrees of freedom. We observe that the cumulative effects of the Polyakov loop and of the regularization procedure contribute to a better description of the thermodynamics, as compared with lattice estimations. We find a faster partial restoration of chiral symmetry and the restoration of the axial symmetry appears as a natural consequence of the full recovering of the chiral symmetry that was dynamically broken. These results show the relevance of the effects of the interplay among the Polyakov loop dynamics, the high momentum quark sates and the restoration of the chiral and axial symmetries at finite temperature.

  7. Critical behaviors near the (tri-)critical end point of QCD within the NJL model

    NASA Astrophysics Data System (ADS)

    Lu, Ya; Du, Yi-Lun; Cui, Zhu-Fang; Zong, Hong-Shi

    2015-10-01

    We investigate the dynamical chiral symmetry breaking and its restoration at finite density and temperature within the two-flavor Nambu-Jona-Lasinio model, and mainly focus on the critical behaviors near the critical end point (CEP) and tricritical point (TCP) of quantum chromodynamics. The multi-solution region of the Nambu and Wigner ones is determined in the phase diagram for the massive and massless current quark, respectively. We use the various susceptibilities to locate the CEP/TCP and then extract the critical exponents near them. Our calculations reveal that the various susceptibilities share the same critical behaviors for the physical current quark mass, while they show different features in the chiral limit.

  8. Low-energy phenomenology of scalarless standard-model extensions with high-energy Lorentz violation

    SciTech Connect

    Anselmi, Damiano; Ciuffoli, Emilio

    2011-03-01

    We consider renormalizable standard model extensions that violate Lorentz symmetry at high energies, but preserve CPT, and do not contain elementary scalar fields. A Nambu-Jona-Lasinio mechanism gives masses to fermions and gauge bosons and generates composite Higgs fields at low energies. We study the effective potential at the leading order of the large-N{sub c} expansion, prove that there exists a broken phase, and study the phase space. In general, the minimum may break invariance under boosts, rotations, and CPT, but we give evidence that there exists a Lorentz invariant phase. We study the spectrum of composite bosons and the low-energy theory in the Lorentz phase. Our approach predicts relations among the parameters of the low-energy theory. We find that such relations are compatible with the experimental data within theoretical errors. We also study the mixing among generations, the emergence of the CKM matrix, and neutrino oscillations.

  9. Violations of parity and charge conjugation in the {theta} vacuum with imaginary chemical potential

    SciTech Connect

    Kouno, Hiroaki; Sakai, Yuji; Sasaki, Takahiro; Kashiwa, Kouji; Yahiro, Masanobu

    2011-04-01

    Charge conjugation (C) and parity (P) are exact symmetries at {theta}={pi} and {Theta}{identical_to}{mu}/(iT)={pi}, where {theta} is the parameter of the so-called {theta} vacuum, {mu} is the imaginary quark-number chemical potential and T is the temperature. Spontaneous breakings of these discrete symmetries are investigated by the Polyakov-loop extended Nambu-Jona-Lasinio model. At zero T, P symmetry is spontaneously broken while C symmetry is conserved. As T increases, P symmetry is restored just after C symmetry is spontaneously broken, so that either P or C symmetry or both the symmetries are spontaneously broken for any T. The chiral-symmetry restoration and the deconfinement transition at {theta}={Theta}=0 are remnants of the P restoration and the C breaking at {theta}={Theta}={pi}, respectively.

  10. Phase diagram in the imaginary chemical potential region and extended Z{sub 3} symmetry

    SciTech Connect

    Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu; Kouno, Hiroaki

    2008-08-01

    Phase transitions in the imaginary chemical potential region are studied by the Polyakov-loop extended Nambu-Jona-Lasinio model that possesses the extended Z{sub 3} symmetry. The extended-Z{sub 3} invariant quantities such as the partition function, the chiral condensate, and the modified Polyakov loop have the Roberge-Weiss (RW) periodicity. There appear four types of phase transitions: deconfinement, chiral, Polyakov-loop RW, and chiral RW transitions. The orders of the chiral and deconfinement transitions depend on the presence or absence of current quark mass, but those of the Polyakov-loop RW and chiral RW transitions do not. The scalar-type, eight-quark interaction newly added in the model makes the chiral transition line shift to the vicinity of the deconfinement transition line.

  11. Vector-type four-quark interaction and its impact on QCD phase structure

    SciTech Connect

    Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu; Kouno, Hiroaki; Matsuzaki, Masayuki

    2008-10-01

    Effects of the vector-type four-quark interaction on QCD phase structure are investigated in the imaginary chemical potential ({mu}) region, by using the Polyakov-loop extended Nambu-Jona-Lasinio model with the extended Z{sub 3} symmetry. We clarify analytically the Roberge-Weiss periodicity and symmetry properties of various quantities under the existence of a vector-type four-quark interaction. In the imaginary {mu} region, the chiral condensate and the quark-number density are sensitive to the strength of the interaction. Based on this result, we propose a possibility to determine the strength of the vector-type interaction, which largely affects QCD phase structure in the real {mu} region, by comparing the results of lattice simulations and effective model calculations in the imaginary {mu} region.

  12. Meson mass at real and imaginary chemical potentials

    SciTech Connect

    Kashiwa, Kouji; Sakai, Yuji; Yahiro, Masanobu; Matsuzaki, Masayuki; Kouno, Hiroaki

    2009-04-01

    Chemical-potential dependence of pi and sigma meson masses is analyzed at both real and imaginary chemical potentials, {mu}{sub R} and {mu}{sub I}, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model that possesses both the extended Z{sub 3} symmetry and chiral symmetry. In the {mu}{sub I} region, the meson masses have the Roberge-Weiss periodicity. The {mu}{sub I} dependence of the meson masses becomes stronger as temperature increases. We argue that meson masses and physical quantities in the {mu}{sub R} region will be determined from lattice QCD data on meson masses in the {mu}{sub I} region by using the PNJL model, if the data are measured in the future.

  13. Kaon fragmentation function from NJL-jet model

    SciTech Connect

    Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang

    2010-07-27

    The NJL-jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters [1]. Earlier studies of the pion fragmentation functions using the Nambu-Jona-Lasinio (NJL) model within this framework showed good qualitative agreement with the empirical parameterizations. Here we extend the NJL-jet model by including the strange quark. The corrections to the pion fragmentation function and corresponding kaon fragmentation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation function exhibit a qualitative agreement with the empirical parameterizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark's. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.

  14. Formation of gapless phases of K{sup 0} condensed color-flavor locked superconducting quark matter

    SciTech Connect

    Zhang Xiaobing; Kapusta, J. I.

    2007-03-01

    Electric and color neutral solutions, and the critical conditions for the formation of gapless color superconductors, are investigated in K{sup 0} condensed color-flavor locked quark matter for nonzero strange quark mass. We show that as the strange quark mass increases, gapless modes for up-strange quark pairing occur first, followed by down-strange quark pairing. The behavior of the gaps, the dispersion relations, and the thermodynamic potential are all found as functions of the strange quark mass on the basis of a Nambu-Jona-Lasinio type model. To a high degree of accuracy, they are presented as relatively simple elementary functions. This allows for easy computation for any reasonable range of baryon chemical potential and strange quark mass.

  15. Equation of State of the Strong Interaction Matter in an External Magnetic Field

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Liu, Yu-Xin

    2015-10-01

    We investigate the equation of state of the strong interaction matter in a background magnetic field via the two flavor Nambu-Jona-Lasinio model. Starting from the mean-field thermodynamical potential density Ω, we calculate the pressure density p, the entropy density s, the energy density ɛ, and the interaction measure (ɛ - 3p)/T4 of the strong interaction matter at finite temperature and finite magnetic field. The results manifest that the chiral phase transition is just a crossover but not a low order phase transition. Moreover there may exist magnetic catalysis effect, and its mechanism is just the effective dimension reduction induced by the magnetic field. Supported by the National Natural Science Foundation of China under Grant Nos. 10935001, 11175004 and 11435001, and the National Key Basic Research Program of China under Grant Nos. G2013CB834400 and 2015CB856900

  16. Analyzing Unfavored Fragmentation Functions Using NJL-Jet Model

    SciTech Connect

    Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang

    2011-10-24

    The Nambu-Jona-Lasinio (NJL)-jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters. The most recent version of the model includes the fragmentation of the light and strange quarks to pions, kaons, nucleons, and antinucleons; where the effects of the production of secondary pions and kaons from the vector mesons {rho}, K* and {phi} are also calculated. The results for the model fragmentation function exhibit a qualitative agreement with the empirical parameterizations. The results also allow to test, within the model assumptions, several assumption in parametrizations of the unfavored fragmentation functions used in empirical fits to the experimental data.

  17. The NJL Model for Quark Fragmentation Functions

    SciTech Connect

    T. Ito, W. Bentz, I. Cloet, A W Thomas, K. Yazaki

    2009-10-01

    A description of fragmentation functions which satisfy the momentum and isospin sum rules is presented in an effective quark theory. Concentrating on the pion fragmentation function, we first explain the reason why the elementary (lowest order) fragmentation process q → qπ is completely inadequate to describe the empirical data, although the “crossed” process π → qq describes the quark distribution functions in the pion reasonably well. Then, taking into account cascade-like processes in a modified jet-model approach, we show that the momentum and isospin sum rules can be satisfied naturally without introducing any ad-hoc parameters. We present numerical results for the Nambu-Jona-Lasinio model in the invariant mass regularization scheme, and compare the results with the empirical parametrizations. We argue that this NJL-jet model provides a very useful framework to calculate the fragmentation functions in an effective chiral quark theory.

  18. Medium modification of hadron masses and the thermodynamics of the hadron resonance gas model

    NASA Astrophysics Data System (ADS)

    Kadam, Guru Prakash; Mishra, Hiranmaya

    2016-02-01

    We study the effect of temperature (T ) and baryon density (μ ) dependent hadron masses on the thermodynamics of hadronic matter. We use linear scaling rule in terms of constituent quark masses for all hadrons except for light mesons. T - and μ -dependent constituent quark masses and the light meson masses are computed using 2 +1 flavor Nambu-Jona-Lasinio (NJL) model. We compute the thermodynamical quantities of hadronic matter within excluded volume hadron resonance gas model (EHRG) with these T - and μ -dependent hadron masses. We confront the thermodynamical quantities with the lattice quantum chromodynamics (LQCD) at μ =0 GeV . Further, we comment on the effect of T - and μ -dependent hadron masses on the transport properties near the transition temperature (Tc).

  19. Phase Structure of Confining Theories on R{sup 3}xS{sup 1}

    SciTech Connect

    Nishimura, Hiromichi; Ogilvie, Michael C.

    2011-05-23

    Recent work on QCD-like theories on R{sup 3}xS{sup 1} has revealed that a confined phase can exist when the circumference L of S{sup 1} is sufficiently small. Adjoint QCD and double-trace deformation theories with certain conditions are such theories, and we present some new results for their phase diagrams. First we show the connection between the large-L and small-L confined regions in the phase diagram of SU(3) adjoint QCD using Polyakov-Nambu-Jona Lasinio models. Then we consider an SU(2) double-trace deformation theory with adjoint scalars and study conflicts between the Higgs and small-L confined phase.

  20. π0-η -η' mixing in a generalized multiquark interaction scheme

    NASA Astrophysics Data System (ADS)

    Osipov, A. A.; Hiller, B.; Blin, A. H.

    2016-06-01

    We investigate the isospin symmetry breaking effects within a recently derived Nambu-Jona-Lasinio related model by fitting the measured pseudoscalar meson masses and weak decay couplings fπ, fK. Our model contains the next to leading order terms in the 1 /Nc expansion of the effective multiquark Lagrangian, including the ones that break the chiral symmetry explicitly. We show the important phenomenological role of these interactions: (1) They lead to an accurate fit of the low-lying pseudoscalar nonet characteristics. (2) They account for a very good agreement of the current quark masses with the present PDG values. (3) They reduce by 40% the ratio ɛ /ɛ' of the π0-η and π0-η' mixing angles, as compared to the case that contemplates explicit breaking only in the leading order, bringing it in consonance with the quoted values in the literature. The conventional NJL-type models fail in the joint description of these parameters.

  1. BEC-BCS crossover in a cold and magnetized two color NJL model

    NASA Astrophysics Data System (ADS)

    Duarte, Dyana C.; Allen, P. G.; Farias, R. L. S.; Manso, Pedro H. A.; Ramos, Rudnei O.; Scoccola, N. N.

    2016-01-01

    The BEC-BCS crossover for a Nambu-Jona-Lasinio (NJL) model with diquark interactions is studied in the presence of an external magnetic field. Particular attention is paid to different regularization schemes used in the literature. A thorough comparison of results is performed for the case of a cold and magnetized two-color NJL model. According to our results, the critical chemical potential for the BEC transition exhibits a clear inverse magnetic catalysis effect for magnetic fields in the range 1 ≲e B /mπ2≲20 . As for the BEC-BCS crossover, the corresponding critical chemical potential is very weakly sensitive to magnetic fields up to e B ˜9 mπ2, showing a much smaller inverse magnetic catalysis as compared to the BEC transition, and displays a strong magnetic catalysis from this point on.

  2. Proper time regularization at finite quark chemical potential

    NASA Astrophysics Data System (ADS)

    Zhang, Jin-Li; Shi, Yuan-Mei; Xu, Shu-Sheng; Zong, Hong-Shi

    2016-04-01

    In this paper, we use the two-flavor Nambu-Jona-Lasinio (NJL) model to study the quantum chromodynamics (QCD) chiral phase transition. To deal with the ultraviolet (UV) issue, we adopt the popular proper time regularization (PTR), which is commonly used not only for hadron physics but also for the studies with magnetic fields. This regularization scheme can introduce the infrared (IR) cutoff to include quark confinement. We generalize the PTR to zero temperature and finite chemical potential case use a completely new method, and then study the chiral susceptibility, both in the chiral limit case and with finite current quark mass. The chiral phase transition is second-order in μ = 0 and T = 0 and crossover at μ≠0 and T = 0. Three sets of parameters are used to make sure that the results do not depend on the parameter choice.

  3. QCD Phase Diagram at Finite Baryon and Isospin Chemical Potentials

    SciTech Connect

    Sasaki, T.; Sakai, Y.; Yahiro, M.; Kouno, H.

    2011-10-21

    The phase structure of two-flavor QCD is explored for finite temperature T and finite baryon- and isospin-chemical potentials, {mu}{sub B} and {mu}{sub I}, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. The PNJL model with the scalar-type eight-quark interaction can reproduce lattice QCD data in the {mu}{sub I}-T plane at {mu}{sub B} = 0. In the {mu}{sub I}-{mu}{sub B}-T space, the critical endpoint of the chiral phase transition in the {mu}{sub B}-T plane at {mu}{sub I} = 0 moves to the tricritical point of the pion-superfluidity phase transition in the {mu}{sub I}-T plane at {mu}{sub B} = 0 as {mu}{sub I} increases.

  4. Entanglement between deconfinement transition and chiral symmetry restoration

    SciTech Connect

    Sakai, Yuji; Sasaki, Takahiro; Yahiro, Masanobu; Kouno, Hiroaki

    2010-10-01

    We extend the Polyakov-loop extended Nambu-Jona-Lasinio model by introducing an effective four-quark vertex depending on the Polyakov loop. The effective vertex generates entanglement interactions between the Polyakov loop and the chiral condensate. The new model is consistent with lattice QCD data at imaginary quark-number chemical potential and real and imaginary isospin chemical potentials, particularly on the strong correlation between the chiral and deconfinement transitions and also on the quark-mass dependence of the order of the Roberge-Weiss endpoint. We investigate the influence of the entanglement interactions on the location of the tricritical point at real isospin chemical potential and on the location of the critical endpoint at real quark-number chemical potential.

  5. Phase diagram in the entanglement PNJL model

    NASA Astrophysics Data System (ADS)

    Friesen, A.; Kalinovsky, Y.; Toneev, V.

    2016-01-01

    Effects of the vector interaction in the Nambu-Jona-Lasinio model with Polyakov loop are studied in combination with the entanglement interaction between the quark and pure gauge sectors. We investigate the QCD phase diagram and find that the first order chiral phase transition at finite baryon chemical potentials and its critical endpoint disappear for sufficiently large values of the vector interaction constant Gv. The presence of an entanglement interaction between quark and pure gauge sectors leads to an increase of the value Gv for which the first order transition disappears. The influence of a nonzero Gv on the curvature of the crossover boundary in the T - μ plane nearby μ= 0 is also examined for both cases.

  6. Determination of U (1 )A restoration from pion and a0 -meson screening masses: Toward the chiral regime

    NASA Astrophysics Data System (ADS)

    Ishii, Masahiro; Yonemura, Koji; Takahashi, Junichi; Kouno, Hiroaki; Yahiro, Masanobu

    2016-01-01

    We incorporate the effective restoration of U (1 )A symmetry in the 2 +1 -flavor entanglement Polyakov-loop extended Nambu-Jona-Lasinio (EPNJL) model by introducing a temperature-dependent strength K (T ) to the Kobayashi-Maskawa-'t Hooft determinant interaction. T dependence of K (T ) is well determined from pion and a0-meson screening masses obtained by lattice QCD (LQCD) simulations with improved p4 staggered fermions. The strength is strongly suppressed in the vicinity of the pseudocritical temperature of chiral transition. The EPNJL model with the K (T ) well reproduces meson susceptibilities calculated by LQCD with domain-wall fermions. The model shows that the chiral transition is second order at the "light-quark chiral-limit" point where the light quark mass is zero and the strange quark mass is fixed at the physical value. This indicates that there exists a tricritical point. Hence, the location is estimated.

  7. Influence of the vector interaction and an external magnetic field on the isentropes near the chiral critical end point

    NASA Astrophysics Data System (ADS)

    Costa, Pedro

    2016-06-01

    The location of the critical end point (CEP) and the isentropic trajectories in the QCD phase diagram are investigated. We use the (2 +1 ) Nambu-Jona-Lasinio model with the Polyakov loop coupling for different scenarios, namely by imposing zero strange quark density, which is the case in the ultrarelativistic heavy ion collisions, and β equilibrium. The influence of strong magnetic fields and of the vector interaction on the isentropic trajectories around the CEP is discussed. It is shown that the vector interaction and the magnetic field, having opposite effects on the first-order transition, affect the isentropic trajectories differently: as the vector interaction increases, the first-order transition becomes weaker and the isentropes become smoother; when a strong magnetic field is considered, the first-order transition is strengthened and the isentropes are pushed to higher temperatures. No focusing of isentropes in region towards the CEP is seen.

  8. Polyakov-loop suppression of colored states in a quark-meson-diquark plasma

    NASA Astrophysics Data System (ADS)

    Blaschke, D.; Dubinin, A.; Buballa, M.

    2015-06-01

    A quark-meson-diquark plasma is considered within the Polyakov-loop extended Nambu-Jona-Lasinio model for dynamical chiral symmetry breaking and restoration in quark matter. Based on a generalized Beth-Uhlenbeck approach to mesons and diquarks we present the thermodynamics of this system including the Mott dissociation of mesons and diquarks at finite temperature. A striking result is the suppression of the diquark abundance below the chiral restoration temperature by the coupling to the Polyakov loop, because of their color degree of freedom. This is understood in close analogy to the suppression of quark distributions by the same mechanism. Mesons as color singlets are unaffected by the Polyakov-loop suppression. At temperatures above the chiral restoration mesons and diquarks are both suppressed due to the Mott effect, whereby the positive resonance contribution to the pressure is largely compensated by the negative scattering contribution in accordance with the Levinson theorem.

  9. Vector meson spectral function and dilepton rate in the presence of strong entanglement effect between the chiral and the Polyakov loop dynamics

    NASA Astrophysics Data System (ADS)

    Islam, Chowdhury Aminul; Majumder, Sarbani; Mustafa, Munshi G.

    2015-11-01

    In this work we have reexplored our earlier study on the vector meson spectral function and its spectral property in the form of dilepton rate in a two-flavor Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model in the presence of a strong entanglement between the chiral and Polyakov loop dynamics. The entanglement considered here is generated through the four-quark scalar-type interaction in which the coupling strength depends on the Polyakov loop and runs with temperature and chemical potential. The entanglement effect is also considered for the four-quark vector-type interaction in the same manner. We observe that the entanglement effect relatively enhances the color degrees of freedom due to the running of both the scalar and vector couplings. This modifies the vector meson spectral function and, thus, the spectral property such as the dilepton production rate in the low invariant mass also gets modified.

  10. Ab initio calculation of a global potential, vibrational energies, and wave functions for HCN/HNC, and a simulation of the (A-tilde)-(X-tilde) emission spectrum

    NASA Technical Reports Server (NTRS)

    Bowman, Joel M.; Gazdy, Bela; Bentley, Joseph A.; Lee, Timothy J.; Dateo, Christopher E.

    1993-01-01

    A potential energy surface for the HCN/HNC system which is a fit to extensive, high-quality ab initio, coupled-cluster calculations is presented. All HCN and HNC states with energies below the energy of the first delocalized state are reported and characterized. Vibrational transition energies are compared with all available experimental data on HCN and HNC, including high CH-overtone states up to 23,063/cm. A simulation of the (A-tilde)-(X-tilde) stimulated emission pumping (SEP) spectrum is also reported, and the results are compared to experiment. Franck-Condon factors are reported for odd bending states of HCN, with one quantum of vibrational angular momentum, in order to compare with the recent assignment by Jonas et al. (1992), on the basis of axis-switching arguments of a number of previously unassigned states in the SEP spectrum.

  11. Quark mass functions and pion structure in Minkowski space

    SciTech Connect

    Biernat, Elmer P.; Gross, Franz L.; Pena, Maria Teresa; Stadler, Alfred

    2014-03-01

    We present a study of the dressed quark mass function and the pion structure in Minkowski space using the Covariant Spectator Theory (CST). The quark propagators are dressed with the same kernel that describes the interaction between different quarks. We use an interaction kernel in momentum space that is a relativistic generalization of the linear confining q-qbar potential and a constant potential shift that defines the energy scale. The confining interaction has a Lorentz scalar part that is not chirally invariant by itself but decouples from the equations in the chiral limit and therefore allows the Nambu--Jona-Lasinio (NJL) mechanism to work. We adjust the parameters of our quark mass function calculated in Minkowski-space to agree with LQCD data obtained in Euclidean space. Results of a calculation of the pion electromagnetic form factor in the relativistic impulse approximation using the same mass function are presented and compared with experimental data.

  12. Betti numbers of graded modules and cohomology of vector bundles

    NASA Astrophysics Data System (ADS)

    Eisenbud, David; Schreyer, Frank-Olaf

    2009-07-01

    In the remarkable paper Graded Betti numbers of Cohen-Macaulay modules and the multiplicity conjecture, Mats Boij and Jonas Soederberg conjectured that the Betti table of a Cohen-Macaulay module over a polynomial ring is a positive linear combination of Betti tables of modules with pure resolutions. We prove a strengthened form of their conjectures. Applications include a proof of the Multiplicity Conjecture of Huneke and Srinivasan and a proof of the convexity of a fan naturally associated to the Young lattice. With the same tools we show that the cohomology table of any vector bundle on projective space is a positive rational linear combination of the cohomology tables of what we call supernatural vector bundles. Using this result we give new bounds on the slope of a vector bundle in terms of its cohomology.

  13. Symmetries in Physics

    NASA Astrophysics Data System (ADS)

    Brading, Katherine; Castellani, Elena

    2003-12-01

    Preface; Copyright acknowledgements; List of contributors; 1. Introduction; Part I. Continuous Symmetries: 2. Classic texts: extracts from Weyl and Wigner; 3. Review paper: On the significance of continuous symmetry to the foundations of physics C. Martin; 4. The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism T. Ryckman; 5. Symmetries and Noether's theorems K. A. Brading and H. R. Brown; 6. General covariance, gauge theories, and the Kretschmann objection J. Norton; 7. The interpretation of gauge symmetry M. Redhead; 8. Tracking down gauge: an ode to the constrained Hamiltonian formalism J. Earman; 9. Time-dependent symmetries: the link between gauge symmetries and indeterminism D. Wallace; 10. A fourth way to the Aharanov-Bohm effect A. Nounou; Part II. Discrete Symmetries: 11. Classic texts: extracts from Lebniz, Kant and Black; 12. Review paper: Understanding permutation symmetry S. French and D. Rickles; 13. Quarticles and the identity of discernibles N. Hugget; 14. Review paper: Handedness, parity violation, and the reality of space O. Pooley; 15. Mirror symmetry: what is it for a relational space to be orientable? N. Huggett; 16. Physics and Leibniz's principles S. Saunders; Part III. Symmetry Breaking: 17: Classic texts: extracts from Curie and Weyl; 18. Extract from G. Jona-Lasinio: Cross-fertilization in theoretical physics: the case of condensed matter and particle physics G. Jona-Lasinio; 19. Review paper: On the meaning of symmetry breaking E. Castellani; 20. Rough guide to spontaneous symmetry breaking J. Earman; 21. Spontaneous symmetry breaking: theoretical arguments and philosophical problems M. Morrison; Part IV. General Interpretative Issues: 22. Classic texts: extracts from Wigner; 23. Symmetry as a guide to superfluous theoretical structure J. Ismael and B. van Fraassen; 24. Notes on symmetries G. Belot; 25. Symmetry, objectivity, and design P. Kosso; 26. Symmetry and equivalence E. Castellani.

  14. Symmetries in Physics

    NASA Astrophysics Data System (ADS)

    Brading, Katherine; Castellani, Elena

    2010-01-01

    Preface; Copyright acknowledgements; List of contributors; 1. Introduction; Part I. Continuous Symmetries: 2. Classic texts: extracts from Weyl and Wigner; 3. Review paper: On the significance of continuous symmetry to the foundations of physics C. Martin; 4. The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism T. Ryckman; 5. Symmetries and Noether's theorems K. A. Brading and H. R. Brown; 6. General covariance, gauge theories, and the Kretschmann objection J. Norton; 7. The interpretation of gauge symmetry M. Redhead; 8. Tracking down gauge: an ode to the constrained Hamiltonian formalism J. Earman; 9. Time-dependent symmetries: the link between gauge symmetries and indeterminism D. Wallace; 10. A fourth way to the Aharanov-Bohm effect A. Nounou; Part II. Discrete Symmetries: 11. Classic texts: extracts from Lebniz, Kant and Black; 12. Review paper: Understanding permutation symmetry S. French and D. Rickles; 13. Quarticles and the identity of discernibles N. Hugget; 14. Review paper: Handedness, parity violation, and the reality of space O. Pooley; 15. Mirror symmetry: what is it for a relational space to be orientable? N. Huggett; 16. Physics and Leibniz's principles S. Saunders; Part III. Symmetry Breaking: 17: Classic texts: extracts from Curie and Weyl; 18. Extract from G. Jona-Lasinio: Cross-fertilization in theoretical physics: the case of condensed matter and particle physics G. Jona-Lasinio; 19. Review paper: On the meaning of symmetry breaking E. Castellani; 20. Rough guide to spontaneous symmetry breaking J. Earman; 21. Spontaneous symmetry breaking: theoretical arguments and philosophical problems M. Morrison; Part IV. General Interpretative Issues: 22. Classic texts: extracts from Wigner; 23. Symmetry as a guide to superfluous theoretical structure J. Ismael and B. van Fraassen; 24. Notes on symmetries G. Belot; 25. Symmetry, objectivity, and design P. Kosso; 26. Symmetry and equivalence E. Castellani.

  15. Facilitating roles of murine platelet glycoprotein Ib and αIIbβ3 in phosphatidylserine exposure during vWF–collagen-induced thrombus formation

    PubMed Central

    Kuijpers, Marijke J E; Schulte, Valerie; Oury, Cécile; Lindhout, Theo; Broers, Jos; Hoylaerts, Marc F; Nieswandt, Bernhard; Heemskerk, Johan W M

    2004-01-01

    Vessel wall damage exposes collagen fibres, to which platelets adhere directly via the collagen receptors glycoprotein (GP) VI and integrin α2β1 and indirectly by collagen-bound von Willebrand factor (vWF) via the GPIb-V-IX and integrin αIIbβ3 receptor complexes. Platelet–collagen interaction under shear stimulates thrombus formation in two ways, by integrin-dependent formation of platelet aggregates and by surface exposure of procoagulant phosphatidylserine (PS). GPVI is involved in both processes, complemented by α2β1. In mouse blood flowing over collagen, we investigated the additional role of platelet–vWF binding via GPIb and αIIbβ3. Inhibition of GPIb as well as blocking of vWF binding to collagen reduced stable platelet adhesion at high shear rate. This was accompanied by delayed platelet Ca2+ responses and reduced PS exposure, while microaggregates were still formed. Inhibition of integrin αIIbβ3 with JON/A antibody, which blocks αIIbβ3 binding to both vWF and fibrinogen, reduced PS exposure and aggregate formation. The JON/A effects were not enhanced by combined blocking of GPIb–vWF binding, suggesting a function for αIIbβ3 downstream of GPIb. Typically, with blood from FcR γ-chain +/− mutant mice, expressing 50% of normal platelet GPVI levels, GPIb blockage almost completely abolished platelet adhesion and PS exposure. Together, these data indicate that, under physiological conditions of flow, both adhesive receptors GPIb and αIIbβ3 facilitate GPVI-mediated PS exposure by stabilizing platelet binding to collagen. Hence, these glycoproteins have an assistant procoagulant role in collagen-dependent thrombus formation, which is most prominent at reduced GPVI activity and is independent of the presence of thrombin. PMID:15155790

  16. Human-induced geomorphology: Modeling slope failure in Dominical, Costa Rica using Landsat imagery

    NASA Astrophysics Data System (ADS)

    Miller, Andrew J.

    Unchecked human development has ravaged the region between Dominical and Uvita, Costa Rica. Much of the development transition has been driven by tourism and further foreign direct investment in residential, service and commercial enterprises. The resulting land-use/land-cover change has removed traditional forest cover in exchange for impervious surfaces, physical structures, and bare ground which is no longer mechanically supported by woody vegetation. Combined with a tropical climate, deeply weathered soils and lithography which are prone to erosion, land cover change has led to an increase in slope failure occurrences. Given the remoteness of the Dominical-Uvita region, its rate of growth and the lack of monitoring, new techniques for monitoring land use and slope failure susceptibility are needed. Two new indices are presented here that employ a Digital Elevation Model (DEM) and widely available Landsat imagery to assist in this endeavor. The first index, or Vegetation Influenced Landslide Index (VILI), incorporates slope derived from a DEM and Lu et al.'s (2007) Surface Cover Index to quantify vegetative cover as a means of mechanical stabilization in landslide prone areas. The second index, or Slope Multiplier Index (SMI), uses individual Landsat data bands and basic Landsat band ratios as environmental proxies to replicate soil, vegetative and hydrologic properties. Both models achieve accuracy over 70% and rival results from more complicated published literature. The accuracy of the indices was assessed with the creation of a landslide inventory developed from field observations occurring in December 2007 and November 2008. The creation of these indices represents an efficient and accurate way of determining landslide susceptibility zonation in data poor areas where environmental protection practitioners may be overextended, under-trained or both.

  17. Pycnogenol, a compound isolated from the bark of pinus maritime mill, attenuates ventilator-induced lung injury through inhibiting NF-κB-mediated inflammatory response

    PubMed Central

    Xia, YF; Zhang, JH; Xu, ZF; Deng, XM

    2015-01-01

    Background: During mechanical ventilation, high end-inspiratory lung volume results in a permeability type pulmonary oedema, called ventilator-induced lung injury (VILI). The pathophysiology of ventilator-induced lung injury involves multiple mechanisms, such as excessive inflammation. And pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have anti-inflammatory activity. Objective: We investigated the effects of pyncogenol on ventilator-induced lung injury in rats. Methods: Rats were orally administrated with pycnogenol once (30 mg/kg) 2 days before lung injury induction with mechanical ventilation, then the rats were divided into three groups: lung-protective ventilation (LV group, n = 20), injurious ventilation (HV group, n = 20), HV + pycnogenol group (HV + Pyc group, n = 20). Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for histopathological examinations and biochemical analyses. Results: Pretreatment with pycnogenol could markedly decrease lung wet/dry ratio, lower myeloperoxidase (MPO) activity and total protein concentration and reduce the production of TNF-α, IL-6, IL-1β and MIP-2 in the BALF in ventilator-induced lung injury rats. Additionally, pycnogenol improved the histology of the lung and significantly inhibited the phosphorylation of NF-κB p65 and the degradation of IκB-α. Conclusion: Pycnogenol treatment could attenuate ventilator-induced lung injury in rats, at least in part, through its ability to reduce the production of inflammatory cytokines via inhibiting the activation of NF-κB, indicating it as a potential therapeutic candidate for ventilator-induced lung injury. PMID:25932110

  18. Investigation of alveolar tissue deformations using OCT combined with fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Gaertner, Maria; Cimalla, Peter; Knels, Lilla; Meissner, Sven; Schnabel, Christian; Kuebler, Wolfgang M.; Koch, Edmund

    2011-06-01

    In critical care medicine, artificial ventilation is a life saving tool providing sufficient blood oxygenation to patients suffering from respiratory failure. Essential for their survival is the use of protective ventilation strategies to prevent further lung damage due to ventilator induced lung injury (VILI). Since there is only little known about implications of lung tissue overdistension on the alveolar level, especially in the case of diseased lungs, this research deals with the investigation of lung tissue deformation on a microscale. A combined setup utilizing optical coherence tomography (OCT) and confocal fluorescence microscopy, is used to study the elastic behavior of the alveolar tissue. Three-dimensional geometrical information with voxel sizes of 6 μm × 6 μm × 11 μm (in air) is provided by OCT, structural information about localization of elastin fibers is elucidated via confocal fluorescence microscopy with a lateral resolution of around 1 μm. Imaging depths of 90 μm for OCT and 20 μm for confocal fluorescence microscopy were obtained. Dynamic studies of subpleural tissue were carried out on the basis of an in vivo mouse model post mortem, mimicking the physiological environment of an intact thorax and facilitating a window for the application of optical methods. Morphological changes were recorded by applying constant positive airway pressures of different values. With this, alveolar volume changes could clearly be recognized and quantified to form a compliance value of 3.5 • 10-6(see manuscript). The distribution of elastin fibers was detected and will be subject to further elasticity analysis.

  19. The influence of Cl, F and Mg ions on the experimental replacement of Carrara marble by apatite

    NASA Astrophysics Data System (ADS)

    Trindade Pedrosa, Elisabete; Putnis, Andrew

    2014-05-01

    Fluid-solid interactions span a very wide range of possible reactions, and are responsible for most of the mineral assemblages in the Earth's crust. Reequilibration processes in a wide range of materials are dominated by dissolution and reprecipitation mechanisms. The interaction of aqueous fluids with these materials results in a remarkable consistency of behaviour, especially in the way that the dissolution and precipitation processes are coupled, and how the relative solubility and molar volume combine to create porosity which allows fluid to continuously migrate to the reaction interface. The recent discovery that the coupling can be manipulated by changing the fluid composition not only emphasizes the role of the fluid in the coupling but opens new avenues for materials syntheses (Putnis, 2009). Recently, a study by Jonas et al., (2013) used as a model the pseudomorphic replacement of Carrara marble (calcite - CaCO3) by calcium phosphates (Ca5P(O4)3(OH, Cl,F) to show that the grain boundaries present in the rock and the transient porosity structures developing throughout the replacement reaction, enabled the reaction front to progress further into the rock, as well as to the center of each single grain until complete transformation. In the present study, the same system was used to explore the rates and evolution of such replacement in the presence of different ions in the fluid used for reaction. Small Carrara marble cubes of around 2 mm3 were treated in hydrothermal reaction vessels at 200°C using phosphate bearing solutions with and without the presence of the different ions: chlorine, fluorine and magnesium. Mounted and polished cross sections of the reacted samples were examined by scanning electron microscopy and electron microprobe analysis to determine the extent of replacement, the textural evolution and the composition of the product phases. Results show that changes in the chemistry of the fluid seem to influence the evolution of the reaction front

  20. Web-based interactive access, analysis and comparison of remotely sensed and in situ measured temperature data

    NASA Astrophysics Data System (ADS)

    Eberle, Jonas; Urban, Marcel; Hüttich, Christian; Schmullius, Christiane

    2014-05-01

    Numerous datasets providing temperature information from meteorological stations or remote sensing satellites are available. However, the challenging issue is to search in the archives and process the time series information for further analysis. These steps can be automated for each individual product, if the pre-conditions are complied, e.g. data access through web services (HTTP, FTP) or legal rights to redistribute the datasets. Therefore a python-based package was developed to provide data access and data processing tools for MODIS Land Surface Temperature (LST) data, which is provided by NASA Land Processed Distributed Active Archive Center (LPDAAC), as well as the Global Surface Summary of the Day (GSOD) and the Global Historical Climatology Network (GHCN) daily datasets provided by NOAA National Climatic Data Center (NCDC). The package to access and process the information is available as web services used by an interactive web portal for simple data access and analysis. Tools for time series analysis were linked to the system, e.g. time series plotting, decomposition, aggregation (monthly, seasonal, etc.), trend analyses, and breakpoint detection. Especially for temperature data a plot was integrated for the comparison of two temperature datasets based on the work by Urban et al. (2013). As a first result, a kernel density plot compares daily MODIS LST from satellites Aqua and Terra with daily means from GSOD and GHCN datasets. Without any data download and data processing, the users can analyze different time series datasets in an easy-to-use web portal. As a first use case, we built up this complimentary system with remotely sensed MODIS data and in situ measurements from meteorological stations for Siberia within the Siberian Earth System Science Cluster (www.sibessc.uni-jena.de). References: Urban, Marcel; Eberle, Jonas; Hüttich, Christian; Schmullius, Christiane; Herold, Martin. 2013. "Comparison of Satellite-Derived Land Surface Temperature and Air

  1. Is the snow of yesterday, the flood of tomorrow?

    NASA Astrophysics Data System (ADS)

    Rössler, Ole; Weingartner, Rolf

    2014-05-01

    "The snow of yesterday, is the flood of tomorrow." This famous quote could just as much be a folk wisdom or a farmer's wisdom, but it describes the social awareness that the water of the winterly snow amounts may lead to flooding in the spring. Furthermore, this common experience finds its confirmation in reality - though only at a first glance. For example, in spring 1999, a major flooding occurred after a winter with the highest snow amounts recorded over the last 30 years. This is to forget that sustained rainfall occurred prior to the flood event. For scientists, the question remains whether and to what extent winterly snow contributes to spring flooding and how this information might help in forecasts. As snow depth measurements are insufficiently for an empirical study, we set up a hydrological model approach, combining the various snow conditions with the different spring weather conditions of the last 29 years (1981-2009). The study was conducted in three mesoscale (380-550 km2) headwater catchments in the Bernese Oberland. We set up the hydrological model WaSiM-ETH and validated the model against runoff and snow water equivalent. Then, we estimated the start of the melting season for each year following the approach of Egli and Jonas (2009). This date and the according SWE serves as the initial condition to model the spring runoff using all weather conditions during the last 29 years (until June). This leads to 841 possible spring runoff series. Assuming that the last 29 years represent a major part of the natural variance, the influence of snow on the spring discharge and the flood peak in specific is presented. We found that the snow amount and the flood peak are not directly correlated as suggested by the saying. But, the snow amount causes primarily higher mean flow values while the effect on spring flood peaks are a function of weather. Thereby, snow conditions primarily alter the disposition of the catchments to a flood event. We estimate the

  2. Collective modes in the color flavor-locked phase.

    SciTech Connect

    Anglani, R.; Mannarelli, M.; Ruggieri, M.

    2011-05-17

    We study the low-energy effective action for some collective modes of the color flavor-locked (CFL) phase of QCD. This phase of matter has long been known to be a superfluid because by picking a phase its order parameter breaks the quark-number U(1){sub B} symmetry spontaneously. We consider the modes describing fluctuations in the magnitude of the condensate, namely the Higgs mode, and in the phase of the condensate, namely the Nambu-Goldstone (NG) (or Anderson-Bogoliubov) mode associated with the breaking of U(1){sub B}. By employing as microscopic theory the Nambu-Jona-Lasinio model, we reproduce known results for the Lagrangian of the NG field to the leading order in the chemical potential and extend such results evaluating corrections due to the gap parameter. Moreover, we determine the interaction terms between the Higgs and the NG field. This study paves the way for a more reliable study of various dissipative processes in rotating compact stars with a quark matter core in the CFL phase.

  3. Weak solution of the non-perturbative renormalization group equation to describe dynamical chiral symmetry breaking

    NASA Astrophysics Data System (ADS)

    Aoki, Ken-Ichi; Kumamoto, Shin-Ichiro; Sato, Daisuke

    2014-04-01

    We analyze dynamical chiral symmetry breaking (Dχ SB) in the Nambu-Jona-Lasinio model by using the non-perturbative renormalization group equation. The equation takes the form of a two-dimensional partial differential equation for the multi-fermion effective interactions V(x,t) where x is the bar {ψ }ψ operator and t is the logarithm of the renormalization scale. The Dχ SB occurs due to the quantum corrections, which means it emerges at some finite tc while integrating the equation with respect to t. At t_c some singularities suddenly appear in V which is compulsory in the spontaneous symmetry breakdown. Therefore there is no solution of the equation beyond tc. We newly introduce the notion of a weak solution to get the global solution including the infrared limit t rArr ∞ and investigate its properties. The obtained weak solution is global and unique, and it perfectly describes the physically correct vacuum even in the case of the first order phase transition appearing in a finite-density medium. The key logic of deduction is that the weak solution we defined automatically convexifies the effective potential when treating the singularities.

  4. Determination of QCD phase diagram from the imaginary chemical potential

    NASA Astrophysics Data System (ADS)

    Yuji, Sakai; Kouji, Kashiwa; Hiroaki, Kouno; Masanobu, Yahiro

    2009-10-01

    Lattice QCD has the well-known sign problem at real chemical potential. An approach to circumvent the problem is the analytic continuation to real chemical potential from imaginary one. We propose a new analytic continuation by using the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model. This work is published in our papers of Phys. Rev. D77, 051901 (2008), Phys. Rev. D78, 036001 (2008), Phys. Rev. D78 076007 (2008), Phys. Rev. D 79, 076008 (2009), Phys. Rev. D 79, 096001 (2009). This talk presents the latest result of these studies. The partition function of QCD has the Roberge-Weiss (RW) periodicity in the imaginary chemical potential region. We revealed that the PNJL model has the RW periodicity. Strength parameters of the vector-type four-quark and scalar-type eight- quark interactions are determined so as to reproduce lattice data on pseudocritical temperatures of the deconfinement and chiral phase transitions in the imaginary chemical potential region. The QCD phase diagram in the real chemical potential region is predicted by the PNJL model. The critical endpoint survives, even if the vector-type four-quark interaction is taken into account.

  5. [Piet de Somer, the University of Leuven and the Belgium poliovaccine in 1956-57].

    PubMed

    Billiau, A

    2011-01-01

    In the years following WW II, all 'Western' countries were struck by recurrent epidemics of infantile paralysis (poliomyelitis). In the early 1950s, a vaccine developed by Jonas Salk in Pittsburgh, became available in the U.S. and Canada. In 1953-54 central virology laboratories in Sweden, Denmark and France were already well advanced in setting up local production lines of the vaccine. At that point in time, the Catholic University of Leuven, on the initiative of the young microbiology professor, Piet De Somer, and in collaboration with the pharmaceutical concern R.I.T. (Recherches et Industries Thérapeutiques, Genval, Belgium), erected a new, multidisciplinary medical research institute, the Rega Institute. One of the research units to be headed by De Somer was destined to introduce the relatively new discipline of virology. As a test case, De Somer decided to venture on developing a production line of the Salk vaccine. In less than one year's time, the project was successful, such that Belgium became one of the first European countries to be self-supporting for its vaccine supply and to be able to initiate a large-scale vaccination campaign. The planning, preparation and execution of the project was accompanied by an extensive correspondence of De Somer with experts and other concerned parties in Belgium and abroad. This correspondence has been preserved and allows for a detailed reconstruction of the remarkable achievement. PMID:22482197

  6. Vaccines today, vaccines tomorrow: a perspective.

    PubMed

    Loucq, Christian

    2013-01-01

    Vaccines are considered as one of the major contributions of the 20th century and one of the most cost effective public health interventions. The International Vaccine Institute has as a mission to discover, develop and deliver new and improved vaccines against infectious diseases that affects developing nations. If Louis Pasteur is known across the globe, vaccinologists like Maurice Hilleman, Jonas Salk and Charles Mérieux are known among experts only despite their contribution to global health. Thanks to a vaccine, smallpox has been eradicated, polio has nearly disappeared, Haemophilus influenzae B, measles and more recently meningitis A are controlled in many countries. While a malaria vaccine is undergoing phase 3, International Vaccine Institute, in collaboration with an Indian manufacturer has brought an oral inactivated cholera vaccine to pre-qualification. The field of vaccinology has undergone major changes thanks to philanthropists such as Bill and Melinda Gates, initiatives like the Decade of Vaccines and public private partnerships. Current researches on vaccines have more challenging targets like the dengue viruses, malaria, human immunodeficiency virus, the respiratory syncytial virus and nosocomial diseases. Exciting research is taking place on new adjuvants, nanoparticles, virus like particles and new route of administration. An overcrowded infant immunization program, anti-vaccine groups, immunizing a growing number of elderlies and delivering vaccines to difficult places are among challenges faced by vaccinologists and global health experts. PMID:23596584

  7. Vaccines today, vaccines tomorrow: a perspective

    PubMed Central

    2013-01-01

    Vaccines are considered as one of the major contributions of the 20th century and one of the most cost effective public health interventions. The International Vaccine Institute has as a mission to discover, develop and deliver new and improved vaccines against infectious diseases that affects developing nations. If Louis Pasteur is known across the globe, vaccinologists like Maurice Hilleman, Jonas Salk and Charles Mérieux are known among experts only despite their contribution to global health. Thanks to a vaccine, smallpox has been eradicated, polio has nearly disappeared, Haemophilus influenzae B, measles and more recently meningitis A are controlled in many countries. While a malaria vaccine is undergoing phase 3, International Vaccine Institute, in collaboration with an Indian manufacturer has brought an oral inactivated cholera vaccine to pre-qualification. The field of vaccinology has undergone major changes thanks to philanthropists such as Bill and Melinda Gates, initiatives like the Decade of Vaccines and public private partnerships. Current researches on vaccines have more challenging targets like the dengue viruses, malaria, human immunodeficiency virus, the respiratory syncytial virus and nosocomial diseases. Exciting research is taking place on new adjuvants, nanoparticles, virus like particles and new route of administration. An overcrowded infant immunization program, anti-vaccine groups, immunizing a growing number of elderlies and delivering vaccines to difficult places are among challenges faced by vaccinologists and global health experts. PMID:23596584

  8. Meeting report VLPNPV: Sessions 1 and 2: Plenary.

    PubMed

    Sainsbury, Frank

    2014-01-01

    Following the highly successful inaugural meeting in 2012, the second installment of Virus-Like Particles and Nano-Particle Vaccines (VLPNPV), proved to be a worthy follow-up in an outstanding conference series. VLPNPV is a forum for academics and industry to address one of the major areas of need in biomedical sciences, the development of novel prophylactic and therapeutic vaccines. The conference was opened by Professor Marianne Manchester of the University of California, San Diego who pointed to the significance of the site chosen for the conference, the Salk Institute. Founded by Jonas Salk, the Salk Institute for Biological Studies is a non-profit, independent research institute with focuses in molecular biology and genetics, neurosciences, and plant biology. This diversity in research themes reflects the wishes of the institute's founder who saw value in using interdisciplinary approaches to understanding the basic principles in life, aimed at generating new therapies and treatments for human disease. Likewise, interdisciplinarity was reflected in the main themes of the meeting, which also highlight some of the potential advantages of virus-like particle (VLP) and nanoparticle vaccines, including novel formulations/adjuvanting effects, structurally accurate/designed antigens, production systems and capacity, and tailoring the immune response. These themes were covered by the 2 plenary sessions that opened the conference and are described in this report. PMID:25485812

  9. [AIDS: "We will win"].

    PubMed

    Chabrier, H

    1989-11-13

    An international colloquium on AIDS held near Paris from October 26-28, 1989, unlike the World Conference on AIDS in Montreal the year before, was able to find reasons for optimism. Significant progress was reported in immunotherapy and in chemotherapy. Successful experiments in vaccinating monkeys against the AIDS virus were reported from the US, France, and Zaire. Time is needed to prove the efficacy of the vaccines because of the slow development in AIDS. A vaccine is being tested by Jonas Salk and collaborators in 75 seropositive volunteers who do not yet show full blown disease but who have very low levels of T4 lymphocytes. Plans are underway for a larger test on 500 seropositive patients at different stages of infection. According to Salk, the new chemical and logical approach toward AIDS will allow combinations of immunotherapy and chemotherapy to destroy the virus. R. Gallo of France listed as accomplishments of the past year a better understanding of the virus, improved case management techniques, increased ability to control Kaposi's sarcoma, considerable progress in the search for a vaccine, and detection of immune proteins that affect the virus. New biological markers permit establishment of correlations between cellular modifications and the progress of the disease as well as the precise effects of treatment. The new immune system drugs immuthiol and DDI are expected to reach the market soon. Patients very soon will be able to receive less toxic alternative treatments, which can be combined for greater efficacy once their toxic interactions are understood. PMID:12342689

  10. Achieving an HIV vaccine: the need for an accelerated national campaign.

    PubMed

    Marlink, R

    1997-11-01

    The development of an effective HIV vaccine has become a crucial national healthcare goal. To develop a worldwide AIDS vaccine, an international collaboration with developing countries is needed. The global approach rationale is threefold: millions of lives can be saved, a vaccine preparation can be tested more rapidly and economically among populations with high rates of infections; and the HIV epidemic comprises at least ten different subtypes. Although a number of barriers to the successful development of an HIV vaccine exist, the polio vaccine can be used as an example to show researchers how to overcome the obstacles. Jonas Salk, the polio vaccine developer, used killed whole virus in a technique that critics argued would not be fully effective. However, the Salk vaccine reduced polio-related paralysis by 72 percent, while the more effective Sabin oral vaccine did not become available until several years later. The lesson to be learned is that any percent of effectiveness is better than nothing, and researchers should not abandon uncertain HIV vaccine development efforts because they believe a better solution may develop in the future. The existence of traditional research should not preclude the development of new solutions that might prove more effective. For example, in the case of polio, the March of Dimes campaign pushed both the Salk and Sabin vaccines despite the skepticism of many academic research groups. PMID:11364812

  11. What you don't know about vaccines can hurt you.

    PubMed

    Pace, Victor M

    2015-01-01

    As physicians, we've all learned in detail about the science behind vaccinations, but I suspect few of us have been taught about the history of vaccinations. Sure, we all know that Dr. Jonas Salk developed the poliovirus vaccine, but I wasn't aware that he inoculated himself, his wife, and his three children with his then experimental vaccine. When our editorial committee decided to focus on vaccinations as our theme for this month's Greene County Medical Society's Journal, I perused the internet for interesting topics. I came across a fascinating website, historyofvaccines.org; this website is a project of the College of Physicians of Philadelphia, touted as being the oldest professional medical organization in the United States. I credit the majority of the information in this article to the above website and the rest to the National Institutes of Health (nih.gov) website; I trust that the information is valid and true, based on the agencies behind these websites. Below are some interesting tidbits about vaccine preventable diseases that I found noteworthy to pass on to our readers. PMID:25958653

  12. "A different kind of beauty": scientific and architectural style in I.M. Pei's Mesa Laboratory and Louis Kahn's Salk Institute.

    PubMed

    Leslie, Stuart W

    2008-01-01

    I.M. Pei's Mesa Laboratory for the National Center for Atmospheric Research in Boulder, Colorado, and Louis Kahn's Salk Institute in La Jolla, California, are rare examples of laboratories as celebrated for their architecture as for their scientific contributions. Completed in the mid-1960s, these signature buildings still express the scientific style of their founding directors, Walter Roberts and Jonas Salk. yet in commissioning their laboratories, Roberts and Salk had to work with architects as strong-willed as themselves. A close reading of the two laboratories reveals the ongoing negotiations and tensions in collaborations between visionary scientist and visionary architect. Moreover, Roberts and Salk also had to become architects of atmospheric and biomedical sciences. For laboratory architecture, however flexible in theory, necessarily stabilizes scientific practice, since a philosophy of research is embedded in the very structure of the building and persists far longer than the initial vision and mission that gave it life. Roberts and Salk's experiences suggest that even the most carefully designed laboratories must successfully adapt to new disciplinary configurations, funding opportunities, and research priorities, or risk becoming mere architectural icons. PMID:20069758

  13. Immunology in Pittsburgh.

    PubMed

    Finn, Olivera J; Salter, Russell D

    2006-01-01

    The University of Pittsburgh School of Medicine has a long tradition of excellence in immunology research and training. Faculty, students, and postdoctoral fellows walk through hallways that are pictorial reminders of the days when Dr. Jonas Salk worked here to develop the polio vaccine, or when Dr. Niels Jerne chaired the Microbiology Department and worked on perfecting the Jerne Plaque Assay for antibody-producing cells. Colleagues and postdoctoral fellows of Professor Salk are still on the faculty of the University of Pittsburgh Medical School as are graduate students of Professor Jerne. A modern research building, the 17 story high Biomedical Science Tower, is a vivid reminder of the day when Dr. Thomas Starzl arrived in Pittsburgh and started building the most prominent solid-organ-transplant program in the world. The immunology research that developed around the problem of graft rejection and tolerance induction trained numerous outstanding students and fellows. Almost 20 yr ago, the University of Pittsburgh founded the University of Pittsburgh Cancer Institute (UPCI) with the renowned immunologist Dr. Ronald Herberman at its helm. This started a number of new research initiatives in cancer immunology and immunotherapy. A large number of outstanding young investigators, as well as several well-established tumor immunologists, were recruited to Pittsburgh at that time. PMID:17337760

  14. [The history of polio in Sweden - from infantile paralysis to polio vaccine].

    PubMed

    Axelsson, Per

    2004-01-01

    Although other epidemics declined due to improved hygiene and sanitation, legislation, and vaccination, polio epidemics appeared in Sweden in 1881 and at the turn of the 20th century the disease became and annual feature in the Swedish epidemiological pattern. Due to the vaccination starting in 1957 epidemics ceased to exist in Sweden around 1965. This article deals with the history polio epidemics in Sweden, 1880-1965 and gives a brief description of: the demographical influence of polio, how did the medical authorities investigate and try to combat it, and the different comprehensions of how polio affected its victims.A study of polio incidence in Sweden at the national level during 1905-1962 reveals that the disease caused major epidemics in 1911-1913 and 1953. At the beginning of the 20th century polio primarily attacked children up to 10 years of age, and at the end of the period victims were represented in all age groups, but mainly in the ages 20-39. Due to its enigmatic appearance, polio was not considered as an epidemic infectious disease during the 19th century. Sweden's early epidemics enabled Swedish medical science to act and together with American research institutes it acquired a leading role in international medical research on the disease. In the 1955 Jonas Salk produced the first successful vaccine against polio but also Sweden developed its own vaccine, different in choice of methods and materials from the widely used Salk-vaccine. PMID:16025605

  15. Rebuilding immunity with Remune.

    PubMed

    Whitfield, L

    1998-01-01

    Remune, an immune response therapy composed of inactivated HIV, is designed to enhance the immune system's ability to recognize and kill HIV proteins. Developed by Dr. Jonas Salk, researchers hope Remune's actions can alter the course of HIV infection and slow disease progression. Remune has gained Food and Drug Administration (FDA) approval to enter the critical Phase III trial stage. Two clinical trials are tracking Remune's immunogenicity (ability to provoke an immune response), its immunogenicity relative to dose level, and its effect on viral load. An ongoing trial, approved in February of 1996, enrolled 2,500 patients at 74 sites. The manufacturer, Immune Response Corporation (IRC), announced earlier this year that treatment with Remune induces an immune response to HIV that cross-reacts with different strains of the virus. This immune response is crucial for developing an effective worldwide treatment. Remune decreases levels of tumor necrosis factor alpha (TNF-a). IRC recently began a Phase I clinical trial in Great Britain that combines Remune with a protease inhibitor, two antiviral nucleoside analogues, and Interleukin-2. The trial is designed to determine the role that the drug may play in restoring immune response. PMID:11365486

  16. Bounds on quantum gravity parameter from the SU(2) NJL effective model of QCD

    NASA Astrophysics Data System (ADS)

    Nozari, K.; Khodadi, M.; Gorji, M. A.

    2015-12-01

    The existence of a minimal measurable length, as an effective cutoff in the ultraviolet regime, is a common feature of all approaches to the quantum gravity proposal. It is widely believed that this length scale will be of the order of the Planck length λ=λ0 l\\text{Pl} , where λ_0∼O(1) is a dimensionless parameter that should be fixed only by the experiments. This issue can be taken into account through the deformed momentum spaces with compact topologies. In this paper, we consider minimum length effects on the physical quantities related to three parameters of the SU(2) Nambu-Jona-Lasinio effective model of QCD by means of the deformed measure which is defined on the compact momentum space with S 3 topology. This measure is suggested by the doubly special relativity theories, Snyder deformed spaces, and the deformed algebra that is obtained in the light of the stability theory of Lie algebras. Using the current experimental data of the particle physics collaboration, we constrain the quantum gravity parameter λ 0 and we compare our results with bounds that are arisen from the other experimental setups.

  17. How can video supported reflection enhance teachers' professional development?

    NASA Astrophysics Data System (ADS)

    McCullagh, John F.

    2012-03-01

    This paper responds to Eva Lundqvist, Jonas Almqvist and Leif Ostman's account of how the manner of teaching can strongly influence pupil learning by recommending video supported reflection as a means by which teachers can transform the nature of their practice. Given the complex nature of the many conditions which influence and control teachers' actions the reframing of routine practice through reflection-in-action can prove challenging. This response paper describes how video can empower teachers to take greater control of their progress and allows for a more social constructivist approach to professional development. Along with a consideration of the difficulties associated with the notion of `reflection' and a short case study, the paper uses Lev Semenovich Vygotsky's zone of proximal development and the notion of scaffolding to propose that video offers a Video Supported Zone of Proximal Development which can ease the process of teacher development. In capturing permanent and exchangeable representations of practice video encourages a collaborative approach to reflection and is consistent with the original ideas of John Dewey.

  18. Dense baryonic matter: Constraints from recent neutron star observations

    NASA Astrophysics Data System (ADS)

    Hell, Thomas; Weise, Wolfram

    2014-10-01

    Updated constraints from neutron star masses and radii impose stronger restrictions on the equation of state for baryonic matter at high densities and low temperatures. The existence of 2M⊙ neutron stars rules out many soft equations of state with prominent "exotic" compositions. The present work reviews the conditions required for the pressure as a function of baryon density to satisfy these constraints. Several scenarios for sufficiently stiff equations of state are evaluated. The common starting point is a realistic description of both nuclear and neutron matter based on a chiral effective field theory approach to the nuclear many-body problem. Possible forms of hybrid matter featuring a quark core in the center of the star are discussed using a three-flavor Polyakov-Nambu-Jona-Lasinio model. It is found that a conventional equation of state based on nuclear chiral dynamics meets the astrophysical constraints. Hybrid matter generally turns out to be too soft unless additional strongly repulsive correlations, e.g., through vector current interactions between quarks, are introduced. The extent to which strangeness can accumulate in the equation of state is also discussed.

  19. Equilibrium sequences of nonrotating and rapidly rotating crystalline color-superconducting hybrid stars

    NASA Astrophysics Data System (ADS)

    Ippolito, Nicola D.; Ruggieri, Marco; Rischke, Dirk H.; Sedrakian, Armen; Weber, Fridolin

    2008-01-01

    The three-flavor crystalline color-superconducting (CCS) phase of quantum chromodynamics (QCD) is a candidate phase for the ground state of cold matter at moderate densities above the density of the deconfinement phase transition. Apart from being a superfluid, the CCS phase has properties of a solid, such as a lattice structure and a shear modulus, and hence the ability to sustain multipolar deformations in gravitational equilibrium. We construct equilibrium configurations of hybrid stars composed of nuclear matter at low, and CCS quark matter at high, densities. Phase equilibrium between these phases is possible only for rather stiff equations of state of nuclear matter and large couplings in the effective Nambu—Jona-Lasinio Lagrangian describing the CCS state. We identify a new branch of stable CCS hybrid stars within a broad range of central densities which, depending on the details of the equations of state, either bifurcate from the nuclear sequence of stars when the central density exceeds that of the deconfinement phase transition or form a new family of configurations separated from the purely nuclear sequence by an instability region. The maximum masses of our nonrotating hybrid configurations are consistent with the presently available astronomical bounds. The sequences of hybrid configurations that rotate near the mass-shedding limit are found to be more compact and thus support substantially larger spins than their same mass nuclear counterparts.

  20. Influence of pions on the hadron-quark phase transition

    SciTech Connect

    Lourenco, O.; Dutra, M.; Frederico, T.; Malheiro, M.; Delfino, A.

    2013-05-06

    In this work we present the features of the hadron-quark phase transition diagrams in which the pions are included in the system. To construct such diagrams we use two different models in the description of the hadronic and quark sectors. At the quark level, we consider two distinct parametrizations of the Polyakov-Nambu-Jona-Lasinio (PNJL) models. In the hadronic side, we use a well known relativistic mean-field (RMF) nonlinear Walecka model. We show that the effect of the pions on the hadron-quark phase diagrams is to move the critical end point (CEP) of the transitions lines. Such an effect also depends on the value of the critical temperature (T{sub 0}) in the pure gauge sector used to parametrize the PNJL models. Here we treat the phase transitions using two values for T{sub 0}, namely, T{sub 0}= 270 MeV and T{sub 0}= 190 MeV. The last value is used to reproduce lattice QCD data for the transition temperature at zero chemical potential.

  1. Effect of Nb on the dynamic recrystallization behavior of high-grade pipeline steels

    NASA Astrophysics Data System (ADS)

    Niu, Tao; Kang, Yong-Lin; Gu, Hong-Wei; Yin, Yu-Qun; Qiao, Ming-Liang; Jiang, Jin-Xing

    2010-12-01

    The dynamic recrystallization (DRX) behavior of high-grade X80/X100 pipeline steels with different Nb contents was investigated through single pass compression experiment using a Gleeble 1500 thermomechanical simulator. By the regression of stress-strain data obtained in the experiment, the deformation activation energy of DRX was identified, and the critical strain was calculated with the Poliak-Jonas (P-J) method. Based on the analysis, the occurrence condition and kinetics of DRX were determined. The results show that as the Nb content increases from 0.08wt% to 0.095wt%, the activation energy of recrystallization raises from 365 to 395 kJ/mol. The critical strain of DRX can be determined more accurately by the P-J method, and the ratios of critical strain to peak strain of X80 and X100 pipeline steels are 0.51 and 0.49, respectively, which are similar to the results achieved by other researchers and calculated with empirical formulae.

  2. Host gene targets for novel influenza therapies elucidated by high-throughput RNA interference screens

    PubMed Central

    Meliopoulos, Victoria A.; Andersen, Lauren E.; Birrer, Katherine F.; Simpson, Kaylene J.; Lowenthal, John W.; Bean, Andrew G. D.; Stambas, John; Stewart, Cameron R.; Tompkins, S. Mark; van Beusechem, Victor W.; Fraser, Iain; Mhlanga, Musa; Barichievy, Samantha; Smith, Queta; Leake, Devin; Karpilow, Jon; Buck, Amy; Jona, Ghil; Tripp, Ralph A.

    2012-01-01

    Influenza virus encodes only 11 viral proteins but replicates in a broad range of avian and mammalian species by exploiting host cell functions. Genome-wide RNA interference (RNAi) has proven to be a powerful tool for identifying the host molecules that participate in each step of virus replication. Meta-analysis of findings from genome-wide RNAi screens has shown influenza virus to be dependent on functional nodes in host cell pathways, requiring a wide variety of molecules and cellular proteins for replication. Because rapid evolution of the influenza A viruses persistently complicates the effectiveness of vaccines and therapeutics, a further understanding of the complex host cell pathways coopted by influenza virus for replication may provide new targets and strategies for antiviral therapy. RNAi genome screening technologies together with bioinformatics can provide the ability to rapidly identify specific host factors involved in resistance and susceptibility to influenza virus, allowing for novel disease intervention strategies.—Meliopoulos, V. A., Andersen, L. E., Birrer, K. F., Simpson, K. J., Lowenthal, J. W., Bean, A. G. D., Stambas, J., Stewart, C. R., Tompkins, S. M., van Beusechem, V. W., Fraser, I., Mhlanga, M., Barichievy, S., Smith, Q., Leake, D., Karpilow, J., Buck, A., Jona, G., Tripp, R. A. Host gene targets for novel influenza therapies elucidated by high-throughput RNA interference screens. PMID:22247330

  3. A cellular automaton model for microstructural simulation of friction stir welded AZ91 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Akbari, Mostafa; Asadi, Parviz; Besharati Givi, MohammadKazem; Zolghadr, Parisa

    2016-03-01

    To predict the grain size and microstructure evolution during friction stir welding (FSW) of AZ91 magnesium alloy, a finite element model (FEM) is developed based on the combination of a cellular automaton model and the Kocks  -  Mecking and Laasraoui-Jonas models. First, according to the flow stress curves and using the Kocks  -  Mecking model, the hardening and recovery parameters and the strain rate sensitivity were calculated. Next, an FEM model was established in Deform-3D software to simulate the FSW of AZ91 magnesium alloy. The results of the FEM model are used in microstructure evolution models to predict the grain size and microstructure of the weld zone. There is a good agreement between the simulated and experimental microstructures, and the proposed model can simulate the dynamic recrystallization (DRX) process during FSW of AZ91 alloy. Moreover, microstructural properties of different points in the SZ as well as the effect of the w/v parameter on the grain size and microstructure are considered.

  4. From quark drops to quark stars. Some aspects of the role of quark matter in compact stars

    NASA Astrophysics Data System (ADS)

    Lugones, Germán

    2016-03-01

    We review some recent results about the mechanism of deconfinement of hadronic matter into quark matter in cold neutron stars and protoneutron stars. We discuss the role of finite-size effects and the relevance of temperature and density fluctuations on the nucleation process. We also examine the importance of surface effects for mixed phases in hybrid stars. A small drop of quark matter nucleated at the core of a compact star may grow if the conversion is sufficiently exothermic. In such a case, it may trigger the burning of the stellar core and even the whole star if quark matter is absolutely stable. We explore the physical processes that occur inside the flame and analyze the hydrodynamic evolution of the combustion front. In the last part of this review, we focus on hybrid stars using the Nambu-Jona-Lasinio (NJL) model with scalar, vector and 't Hooft interactions, paying particular attention to a generalized non-standard procedure for the choice of the "bag constant". We also describe the non-radial oscillation modes of hadronic, hybrid and strange stars with maximum masses above 2M_{odot} and show that the frequency of the p1 and g fluid modes contains key information about the internal composition of compact objects.

  5. Inhomogeneity driven by Higgs instability in a gapless superconductor

    SciTech Connect

    Giannakis, Ioannis; Hou Defu; Huang Mei; Ren Haicang

    2007-01-01

    The fluctuations of the Higgs and pseudo Nambu-Goldstone fields in the 2-flavor color superconductivity (2SC) phase with mismatched pairing are described in the nonlinear realization framework of the gauged Nambu-Jona-Lasinio model. In the gapless 2SC phase, not only Nambu-Goldstone currents can be spontaneously generated, but also the Higgs field exhibits instablity. The Nambu-Goldstone currents generation indicates the formation of the single plane wave Larkin-Ovchinnikov-Fulde-Ferrel state and breaks rotation symmetry, while the Higgs instability favors spatial inhomogeneity and breaks translation invariance. In this paper, we focus on the Higgs instability which has not drawn much attention yet. The Higgs instability cannot be removed without a long range force, thus it persists in the gapless superfluidity and induces phase separation. In the case of gapless 2-flavor color superconductivity state, the Higgs instability can only be partially removed by the electric Coulomb energy. However, it is not excluded that the Higgs instability might be completely removed in the charge neutral gapless color-flavor locked phase by the color Coulomb energy.

  6. A Critical Assessment of Three Usual Equations for Strain Hardening and Dynamic Recovery

    NASA Astrophysics Data System (ADS)

    Montheillet, Frank; Piot, David; Matougui, Nedjoua; Fares, Mohamed Lamine

    2014-09-01

    The Laasraoui-Jonas (LJ), Kocks-Mecking (KM), and power law (PW) stress-strain equations pertaining to hot working of metals within the range of moderate strains ( i.e., before the occurrence of dynamic recrystallization) are compared. It is shown that it is not possible to select the "best" one to fit a given experimental flow curve, neither in the σ - ɛ nor in the diagram. Noting that each of the three laws depends on two constitutive parameters, transformation formulae are then derived allowing the parameters of one law to be derived from the parameters of any of the two others. The fit of a given LJ equation by a PW law is then discussed. Finally, the transformation formulae are used to estimate the current rate of dynamic recovery when the flow rule is known in the form a PW law. The above theoretical derivations are illustrated by the specific case of a Fe-C alloy in the ferritic phase domain. However, they suggest that the conclusions are widely applicable to hot working of metals and alloys.

  7. Quark matter under strong magnetic fields

    NASA Astrophysics Data System (ADS)

    Peres Menezes, Débora; Laércio Lopes, Luiz

    2016-02-01

    We revisit three of the mathematical formalisms used to describe magnetized quark matter in compact objects within the MIT and the Nambu-Jona-Lasinio models and then compare their results. The tree formalisms are based on 1) isotropic equations of state, 2) anisotropic equations of state with different parallel and perpendicular pressures and 3) the assumption of a chaotic field approximation that results in a truly isotropic equation of state. We have seen that the magnetization obtained with both models is very different: while the MIT model produces well-behaved curves that are always positive for large magnetic fields, the NJL model yields a magnetization with lots of spikes and negative values. This fact has strong consequences on the results based on the existence of anisotropic equations of state. We have also seen that, while the isotropic formalism results in maximum stellar masses that increase considerably when the magnetic fields increase, maximum masses obtained with the chaotic field approximation never vary more than 5.5%. The effect of the magnetic field on the radii is opposed in the MIT and NJL models: with both formalisms, isotropic and chaotic field approximation, for a fixed mass, the radii increase with the increase of the magnetic field in the MIT bag model and decrease in the NJL, the radii of quark stars described by the NJL model being smaller than the ones described by the MIT model.

  8. QCD phase diagram at finite baryon and isospin chemical potentials

    SciTech Connect

    Sasaki, Takahiro; Sakai, Yuji; Yahiro, Masanobu; Kouno, Hiroaki

    2010-12-01

    The phase structure of two-flavor QCD is explored for thermal systems with finite baryon- and isospin-chemical potentials, {mu}{sub B} and {mu}{sub iso}, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. The PNJL model with the scalar-type eight-quark interaction can reproduce lattice QCD data at not only {mu}{sub iso}={mu}{sub B}=0, but also {mu}{sub iso}>0 and {mu}{sub B}=0. In the {mu}{sub iso}-{mu}{sub B}-T space, where T is temperature, the critical endpoint of the chiral phase transition in the {mu}{sub B}-T plane at {mu}{sub iso}=0 moves to the tricritical point of the pion-superfluidity phase transition in the {mu}{sub iso}-T plane at {mu}{sub B}=0 as {mu}{sub iso} increases. The thermodynamics at small T is controlled by {radical}({sigma}{sup 2}+{pi}{sup 2}) defined by the chiral and pion condensates, {sigma} and {pi}.

  9. Constitutive modeling of polycarbonate over a wide range of strain rates and temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Haitao; Zhou, Huamin; Huang, Zhigao; Zhang, Yun; Zhao, Xiaoxuan

    2016-06-01

    The mechanical behavior of polycarbonate was experimentally investigated over a wide range of strain rates ( 10^{-4} to 5× 103 s^{-1}) and temperatures (293 to 353 K). Compression tests under these conditions were performed using a SHIMADZU universal testing machine and a split Hopkinson pressure bar. Falling weight impact testing was carried out on an Instron Dynatup 9200 drop tower system. The rate- and temperature-dependent deformation behavior of polycarbonate was discussed in detail. Dynamic mechanical analysis (DMA) tests were utilized to observe the glass ( α ) transition and the secondary ( β ) transition of polycarbonate. The DMA results indicate that the α and β transitions have a dramatic influence on the mechanical behavior of polycarbonate. The decompose/shift/reconstruct (DSR) method was utilized to decompose the storage modulus into the α and β components and extrapolate the entire modulus, the α-component modulus and the β-component modulus. Based on three previous models, namely, Mulliken-Boyce, G'Sell-Jonas and DSGZ, an adiabatic model is proposed to predict the mechanical behavior of polycarbonate. The model considers the contributions of both the α and β transitions to the mechanical behavior, and it has been implemented in ABAQUS/Explicit through a user material subroutine VUMAT. The model predictions are proven to essentially coincide with the experimental results during compression testing and falling weight impact testing.

  10. Quark matter in a parallel electric and magnetic field background: Chiral phase transition and equilibration of chiral density

    NASA Astrophysics Data System (ADS)

    Ruggieri, M.; Peng, G. X.

    2016-05-01

    In this article, we study spontaneous chiral symmetry breaking for quark matter in the background of static and homogeneous parallel electric field E and magnetic field B . We use a Nambu-Jona-Lasinio model with a local kernel interaction to compute the relevant quantities to describe chiral symmetry breaking at a finite temperature for a wide range of E and B . We study the effect of this background on the inverse catalysis of chiral symmetry breaking for E and B of the same order of magnitude. We then focus on the effect of the equilibration of chiral density n5 , produced dynamically by an axial anomaly on the critical temperature. The equilibration of n5 , a consequence of chirality-flipping processes in the thermal bath, allows for the introduction of the chiral chemical potential μ5, which is computed self-consistently as a function of the temperature and field strength by coupling the number equation to the gap equation and solving the two within an expansion in E /T2 , B /T2 , and μ52/T2 . We find that even if chirality is produced and equilibrates within a relaxation time τM , it does not change drastically the thermodynamics, with particular reference to the inverse catalysis induced by the external fields, as long as the average μ5 at equilibrium is not too large.

  11. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    NASA Astrophysics Data System (ADS)

    Shao, Guo-yun; Tang, Zhan-duo; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-07-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu-Jona-Lasinio (PNJL) model with an explicit chemical potential dependence of Polyakov loop potential (μ PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the μ -dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of u , d quarks in the hadron-quark coexisting phase, and analyze the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and properties of the mixed phase would bring relevant information on the expected chemical potential dependence of the Polyakov loop contribution.

  12. Critical spectrum of fluctuations for deconfinement at protoneutron star cores

    SciTech Connect

    Lugones, G.; Grunfeld, A. G.

    2011-10-15

    We study the deconfinement of hadronic matter into quark matter in a protoneutron star focusing on the effects of the finite size on the formation of just deconfined color superconducting quark droplets embedded in the hadronic environment. The hadronic phase is modeled by the nonlinear Walecka model at finite temperature including the baryon octet and neutrino trapping. For quark matter we use an SU(3){sub f} Nambu-Jona-Lasinio model including color superconductivity. The finite size effects on the just deconfined droplets are considered in the frame of the multiple reflection expansion. In addition, we consider that just deconfined quark matter is transitorily out of equilibrium respect to weak interaction, and we impose color neutrality and flavor conservation during the transition. We calculate self-consistently the surface tension and curvature energy density of the quark hadron interphase and find that it is larger than the values typically assumed in the literature. The transition density is calculated for drops of different sizes, and at different temperatures and neutrino trapping conditions. Then, we show that energy density fluctuations are much more relevant for deconfinement than temperature and neutrino density fluctuations. We calculate the critical size spectrum of energy density fluctuations that allows deconfinement as well as the nucleation rate of each critical bubble. We find that drops with any radii smaller than 800 fm can be formed at a huge rate when matter achieves the bulk transition limit of 5-6 times the nuclear saturation density.

  13. Polio and Nobel prizes: looking back 50 years.

    PubMed

    Norrby, Erling; Prusiner, Stanley B

    2007-05-01

    In 1954, John Enders, Thomas Weller, and Frederick Robbins were awarded the Nobel Prize in Physiology or Medicine "for their discovery of the ability of poliomyelitis viruses to grow in cultures of various types of tissue."5370 This discovery provided for the first time opportunities to produce both inactivated and live polio vaccines. By searching previously sealed Nobel Committee archives, we were able to review the deliberations that led to the award. It appears that Sven Gard, who was Professor of Virus Research at the Karolinska Institute and an adjunct member of the Nobel Committee at the time, played a major role in the events leading to the awarding of the Prize. It appears that Gard persuaded the College of Teachers at the Institute to decide not to follow the recommendation by their Nobel Committee to give the Prize to Vincent du Vigneaud. Another peculiar feature of the 1954 Prize is that Weller and Robbins were included based on only two nominations submitted for the first time that year. In his speech at the Nobel Prize ceremony, Gard mentioned the importance of the discovery for the future production of vaccines, but emphasized the implications of this work for growing many different, medically important viruses. We can only speculate on why later nominations highlighting the contributions of scientists such as Jonas Salk, Hilary Koprowski, and Albert Sabin in the development of poliovirus vaccines have not been recognized by a Nobel Prize. PMID:17469121

  14. Confinement, quark mass functions, and spontaneous chiral symmetry breaking in Minkowski space

    SciTech Connect

    Biernat, Elmar P.; Gross, Franz L.; Pena, Teresa; Stadler, Alfred

    2014-01-01

    We formulate the covariant equations for quark-antiquark bound states in Minkowski space in the framework of the Covariant Spectator Theory. The quark propagators are dressed with the same kernel that describes the interaction between different quarks. We show that these equations are charge conjugation invariant, and that in the chiral limit of vanishing bare quark mass, a massless pseudoscalar bound state is produced in a Nambu--Jona-Lasinio (NJL) mechanism, which is associated with the Goldstone boson of spontaneous chiral symmetry breaking. In this introductory paper we test the formalism by using a simplified kernel consisting of a momentum-space $\\delta$-function with a vector Lorentz structure, to which one adds a mixed scalar and vector confining interaction. The scalar part of the confining interaction is not chirally invariant by itself, but decouples from the equations in the chiral limit and therefore allows the NJL mechanism to work. With this model we calculate the quark mass function, and we compare our Minkowski-space results to LQCD data obtained in Euclidean space. In a companion paper we apply this formalism to a calculation of the pion form factor.

  15. Quark matter symmetry energy and quark stars

    SciTech Connect

    Chu, Peng-Cheng; Chen, Lie-Wen

    2014-01-10

    We extend the confined-density-dependent-mass (CDDM) model to include isospin dependence of the equivalent quark mass. Within the confined-isospin-density-dependent-mass (CIDDM) model, we study the quark matter symmetry energy, the stability of strange quark matter, and the properties of quark stars. We find that including isospin dependence of the equivalent quark mass can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. While the recently discovered large mass pulsars PSR J1614–2230 and PSR J0348+0432 with masses around 2 M {sub ☉} cannot be quark stars within the CDDM model, they can be well described by quark stars in the CIDDM model. In particular, our results indicate that the two-flavor u-d quark matter symmetry energy should be at least about twice that of a free quark gas or normal quark matter within the conventional Nambu-Jona-Lasinio model in order to describe PSR J1614–2230 and PSR J0348+0432 as quark stars.

  16. Observables in ultrarelativistic heavy-ion collisions from two different transport approaches for the same initial conditions

    NASA Astrophysics Data System (ADS)

    Marty, R.; Bratkovskaya, E.; Cassing, W.; Aichelin, J.

    2015-07-01

    For nucleus-nucleus collisions at energies currently available at the BNL Relativistic Heavy Ion Collider (RHIC), we calculate observables in two different transport approaches, i.e., the n -body molecular dynamical model "relativistic quantum molecular dynamics for strongly interacting matter with phase transition or crossover" (RSP) and the two-body parton hadron string dynamics (PHSD), starting out from the same distribution in the initial energy density at the quark gluon plasma (QGP) formation time. The RSP dynamics is based on the Nambu-Jona-Lasinio (NJL) Lagrangian, whereas in PHSD the partons are described by the dynamical quasiparticle model (DQPM). Despite the very different description of the parton properties and their interactions and of the hadronization in both approaches, the final transverse momentum distributions of pions turn out to be quite similar, which is less visible for the strange mesons owing to the large NJL cross sections involved. Our findings can be attributed, in part, to a partial thermalization of the quark degrees of freedom in central Au +Au collisions for both approaches. The rapidity distribution of mesons shows a stronger sensitivity to the nature of the degrees of freedom involved and to their interaction strength in the QGP.

  17. The Use of Elasto-Visco-Plastic Material Model Coupled with Pressure-Volume Thermodynamic Relationship to Simulate the Stretch Blow Molding of Polyethylene Terephthalate

    NASA Astrophysics Data System (ADS)

    Mir, H.; Benrabah, Z.; Thibault, F.

    2007-05-01

    The use of polyethylene terephthalate (PET) in the stretch blow molding process presents several challenging issues due to various processing parameters and complex behavior of the material, which is both temperature and strain-rate dependent. In this paper, we generalize the G'Sell-Jonas law in 3D to model and simulate the elasto-visco-plastic (EVP) behavior of PET, taking into account strain-hardening and strain-softening. It is observed that the internal pressure (inside the preform) is significantly different from the nominal pressure (imposed in the blowing device upstream) since the internal pressure and the enclosed volume of the preform are fully coupled. In order to accurately simulate this phenomenon, a thermodynamic model was used to characterize the pressure-volume relationship (PVR). The predicted pressure evolution is thus more realistic when imposing only the machine power of the blowing device (air compressor or vacuum pump). Mechanical and temperature equilibrium equations are fully nonlinear and solved separately with implicit schemes on the current deformed configuration, which is updated at each time step. Biaxial characterization tests were used to determine the model parameters in order to simulate the stretch blow molding process using the pressure-volume thermodynamic relationship. To validate this model, thickness predictions for three industrial cases will be presented and compared to experimental measurements.

  18. Toward a first-principle derivation of confinement and chiral-symmetry-breaking crossover transitions in QCD

    SciTech Connect

    Kondo, Kei-Ichi

    2010-09-15

    We give a theoretical framework to obtain a low-energy effective theory of quantum chromodynamics (QCD) towards a first-principle derivation of confinement/deconfinement and chiral-symmetry breaking/restoration crossover transitions. In fact, we demonstrate that an effective theory obtained using simple but nontrivial approximations within this framework enables us to treat both transitions simultaneously on equal footing. A resulting effective theory is regarded as a modified and improved version of nonlocal Polyakov-loop extended Nambu-Jona-Lasinio (nonlocal PNJL) models proposed recently by Hell, Roessner, Cristoforetti, and Weise, and Sasaki, Friman, and Redlich, extending the original (local) PNJL model by Fukushima and others. A novel feature is that the nonlocal NJL coupling depends explicitly on the temperature and Polyakov loop, which affects the entanglement between confinement and chiral-symmetry breaking, together with the cross term introduced through the covariant derivative in the quark sector considered in the conventional PNJL model. The chiral-symmetry breaking/restoration transition is controlled by the nonlocal NJL interaction, while the confinement/deconfinement transition in the pure gluon sector is specified by the nonperturbative effective potential for the Polyakov loop obtained recently by Braun, Gies, Marhauser, and Pawlowski. The basic ingredients are a reformulation of QCD based on new variables and the flow equation of the Wetterich type in the Wilsonian renormalization group. This framework can be applied to investigate the QCD phase diagram at finite temperature and density.

  19. Toward a first-principle derivation of confinement and chiral-symmetry-breaking crossover transitions in QCD

    NASA Astrophysics Data System (ADS)

    Kondo, Kei-Ichi

    2010-09-01

    We give a theoretical framework to obtain a low-energy effective theory of quantum chromodynamics (QCD) towards a first-principle derivation of confinement/deconfinement and chiral-symmetry breaking/restoration crossover transitions. In fact, we demonstrate that an effective theory obtained using simple but nontrivial approximations within this framework enables us to treat both transitions simultaneously on equal footing. A resulting effective theory is regarded as a modified and improved version of nonlocal Polyakov-loop extended Nambu-Jona-Lasinio (nonlocal PNJL) models proposed recently by Hell, Rössner, Cristoforetti, and Weise, and Sasaki, Friman, and Redlich, extending the original (local) PNJL model by Fukushima and others. A novel feature is that the nonlocal NJL coupling depends explicitly on the temperature and Polyakov loop, which affects the entanglement between confinement and chiral-symmetry breaking, together with the cross term introduced through the covariant derivative in the quark sector considered in the conventional PNJL model. The chiral-symmetry breaking/restoration transition is controlled by the nonlocal NJL interaction, while the confinement/deconfinement transition in the pure gluon sector is specified by the nonperturbative effective potential for the Polyakov loop obtained recently by Braun, Gies, Marhauser, and Pawlowski. The basic ingredients are a reformulation of QCD based on new variables and the flow equation of the Wetterich type in the Wilsonian renormalization group. This framework can be applied to investigate the QCD phase diagram at finite temperature and density.

  20. Neutrality of a magnetized two-flavor quark superconductor

    NASA Astrophysics Data System (ADS)

    Mandal, Tanumoy; Jaikumar, Prashanth

    2013-04-01

    We investigate the effect of electric and color charge neutrality on the two-flavor color superconducting (2SC) phase of cold and dense quark matter in presence of constant external magnetic fields and at moderate baryon densities. Within the framework of the Nambu-Jona-Lasinio (NJL) model, we study the interdependent evolution of the quark's BCS gap and constituent mass with increasing density and magnetic field. While confirming previous results derived for the highly magnetized 2SC phase with color neutrality alone, we obtain new results as a consequence of imposing charge neutrality. In the charge neutral gapless 2SC phase (g2SC), a large magnetic field drives the color superconducting phase transition to a crossover, while the chiral phase transition is first order. At larger diquark-to-scalar coupling ratio GD/GS, where the 2SC phase is preferred, we see hints of the Clogston-Chandrasekhar limit at a very large value of the magnetic field (B˜1019G), but this limit is strongly affected by Shubnikov de Haas-van Alphen oscillations of the gap, indicating the transition to a domain-like state.

  1. Properties of mesons in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Fu, Wei-jie; Liu, Yu-xin

    2016-06-01

    By extending the Φ -derivable approach in the Nambu-Jona-Lasinio model to a finite magnetic field we calculate the properties of pion, σ , and ρ mesons in a magnetic field at finite temperature not only in the quark-antiquark bound state scheme but also in the pion-pion scattering resonant state scenario. Our calculation as a result makes manifest that the masses of π 0 and σ meson can be nearly degenerate at the pseudo-critical temperature which increases with increasing magnetic field strength, and the π ^{± } mass ascends suddenly at almost the same critical temperature. Meanwhile the ρ mesons' masses decrease with the temperature but increase with the magnetic field strength. We also check the Gell-Mann-Oakes-Renner relation and find that the relation can be violated clearly with increasing temperature, and the effect of the magnetic field becomes pronounced around the critical temperature. With different criteria, we analyze the effect of the magnetic field on the chiral phase transition and find that the pseudo-critical temperature of the chiral phase cross, T_c^{χ }, is always enhanced by the magnetic field. Moreover, our calculations indicate that the ρ mesons will get melted as the chiral symmetry has not yet been restored, but the σ meson does not disassociate even at very high temperature. Particularly, it is the first to show that there does not exist a vector meson condensate in the QCD vacuum in the pion-pion scattering scheme.

  2. Influence of the inverse magnetic catalysis and the vector interaction in the location of the critical end point

    NASA Astrophysics Data System (ADS)

    Costa, Pedro; Ferreira, Márcio; Menezes, Débora P.; Moreira, João; Providência, Constança

    2015-08-01

    The effect of a strong magnetic field on the location of the critical end point (CEP) in the QCD phase diagram is discussed under different scenarios. In particular, we consider the contribution of the vector interaction and take into account the inverse magnetic catalysis obtained in lattice QCD calculations at zero chemical potential. The discussion is realized within the (2 +1 ) Polyakov-Nambu-Jona-Lasinio model. It is shown that the vector interaction and the magnetic field have opposite competing effects, and that the winning effect depends strongly on the intensity of the magnetic field. The inverse magnetic catalysis at zero chemical potential has two distinct effects for magnetic fields above ≳0.3 GeV2: it shifts the CEP to lower chemical potentials, hinders the increase of the CEP temperature and prevents a too large increase of the baryonic density at the CEP. For fields e B <0.1 GeV2 the competing effects between the vector contribution and the magnetic field can move the CEP to regions of temperature and density in the phase diagram that could be more easily accessible to experiments.

  3. Quark Number Fluctuations in a Chiral Model with a Magnetic Field

    NASA Astrophysics Data System (ADS)

    Cheng, Lidens; Incera, Vivian

    2013-04-01

    An important consequence of quantum chromodynamics (QCD) is the existence of a phase transition between the hadronic and quark-gluon phases. The hadronic phase exhibits confinement and broken chiral symmetry. The quark-gluon phase exhibits deconfinement and chiral symmetry. The phase boundary can be seen in the temperature-quark chemical potential plane. For large chemical potential, there is a first order chiral transition. For small chemical potential and 2 massless quarks flavors, there is a second order chiral transition. Thus, a critical end point (CEP) is expected where the first order phase transitions end. In the chiral limit or for finite quark masses, the net quark number susceptibility diverges at the CEP. However, when clear from the CEP, it is finite. Hence, the net quark number susceptibility is non-monotonic along the phase boundary if there is a CEP. In this case, the Nambu--Jona-Lasinio model is composed at finite temperature and quark and isospin chemical potentials. The addition of a strong magnetic field in the model is significant because strong magnetic fields are produced in off-central heavy-ion collisions and are present at the core of neutron stars.

  4. Determination of hadron-quark phase transition line from lattice QCD and two-solar-mass neutron star observations

    NASA Astrophysics Data System (ADS)

    Sugano, Junpei; Kouno, Hiroaki; Yahiro, Masanobu

    2016-07-01

    We aim at drawing the hadron-quark phase transition line in the QCD phase diagram by using the two-phase model (TPM) in which the entanglement Polyakov-loop extended Nambu-Jona-Lasinio (EPNJL) model with the vector-type four-quark interaction is used for the quark phase and the relativistic mean field (RMF) model is used for the hadron phase. A reasonable TPM is constructed by using lattice QCD data and neutron star observations as reliable constraints. For the EPNJL model, we determine the strength of vector-type four-quark interaction at zero quark chemical potential from lattice QCD data on quark number density normalized by its Stefan-Boltzmann limit. For the hadron phase, we consider three RMF models: NL3; TM1; and the model proposed by Maruyama, Tatsumi, Endo, and Chiba (MTEC). We find that MTEC is most consistent with the neutron star observations and TM1 is the second best. Assuming that the hadron-quark phase transition occurs in the core of a neutron star, we explore the density dependence of vector-type four-quark interaction. Particularly for the critical baryon chemical potential μBc at zero temperature, we determine a range of μBc for the quark phase to occur in the core of a neutron star. The values of μBc lie in the range 1560 MeV ≤μBc≤1910 MeV .

  5. Confronting effective models for deconfinement in dense quark matter with lattice data

    NASA Astrophysics Data System (ADS)

    Andersen, Jens O.; Brauner, Tomáš; Naylor, William R.

    2015-12-01

    Ab initio numerical simulations of the thermodynamics of dense quark matter remain a challenge. Apart from the infamous sign problem, lattice methods have to deal with finite volume and discretization effects as well as with the necessity to introduce sources for symmetry-breaking order parameters. We study these artifacts in the Polyakov-loop-extended Nambu-Jona-Lasinio (PNJL) model and compare its predictions to existing lattice data for cold and dense two-color matter with two flavors of Wilson quarks. To achieve even qualitative agreement with lattice data requires the introduction of two novel elements in the model: (i) explicit chiral symmetry breaking in the effective contact four-fermion interaction, referred to as the chiral twist, and (ii) renormalization of the Polyakov loop. The feedback of the dense medium to the gauge sector is modeled by a chemical-potential-dependent scale in the Polyakov-loop potential. In contrast to previously used analytical Ansätze, we determine its dependence on the chemical potential from lattice data for the expectation value of the Polyakov loop. Finally, we propose adding a two-derivative operator to our effective model. This term acts as an additional source of explicit chiral symmetry breaking, mimicking an analogous term in the lattice Wilson action.

  6. Dual condensates at finite isospin chemical potential

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao; Miao, Qing

    2016-02-01

    The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential μI in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for μI >mπ / 2 under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with T is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with T at low temperatures due to the influence of pion condensate. We also find that the dressed Polyakov-loop always rises most steeply at the chiral transition temperature, which is consistent with the previous results in Nambu-Jona-Lasinio (NJL) model and its variants without considering the center symmetry. Since both quantities are strongly affected by the chiral symmetry and pion condensation, we conclude that it is difficult to clarify the deconfinement transition from the dual condensates in this situation within this model.

  7. Phase structure of two-color QCD at real and imaginary chemical potentials: Lattice simulations and model analyses

    NASA Astrophysics Data System (ADS)

    Makiyama, Takahiro; Sakai, Yuji; Saito, Takuya; Ishii, Masahiro; Takahashi, Junichi; Kashiwa, Kouji; Kouno, Hiroaki; Nakamura, Atsushi; Yahiro, Masanobu

    2016-01-01

    We investigate the phase structure of two-color QCD at both real and imaginary chemical potentials (μ ), performing lattice simulations and analyzing the data with the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. Lattice QCD simulations are done on an 83×4 lattice with the clover-improved two-flavor Wilson fermion action and the renormalization-group-improved Iwasaki gauge action. We test the analytic continuation of physical quantities from imaginary μ to real μ by comparing lattice QCD results calculated at real μ with the results of an analytic function, the coefficients of which are determined from lattice QCD results at imaginary μ . We also test the validity of the PNJL model by comparing model results with lattice QCD ones. The PNJL model is good in the deconfinement region, but less accurate in the transition and confinement regions. This problem is cured by introducing the baryon degree of freedom to the model. It is also found that the vector-type four-quark interaction is necessary to explain lattice data on the quark number density.

  8. Entanglement interaction and the phase diagram of strongly interacting matter

    NASA Astrophysics Data System (ADS)

    Shao, G. Y.; Tang, Z. D.; Di Toro, M.; Colonna, M.; Gao, X. Y.; Gao, N.; Zhao, Y. L.

    2015-12-01

    The entanglement interactions between the Polyakov loop and chiral condensate have been recently studied in the entangled Polyakov-loop Nambu-Jona-Lasinio model (EPNJL). The calculation shows that such an interaction plays an important role in the pseudocritical temperatures of deconfinement and chiral symmetry restoration. As a further study, here we construct a hadron-quark two-equation-of-state (two-EoS) model, based on the Walecka-quantum hadrodynamics and the EPNJL pictures, in order to study the equilibrium transition between hadronic and quark matter in heavy-ion collisions at finite densities and temperatures. We can explore the phase diagram of strongly interacting matter and the transition boundaries from nuclear to quark matter. We discuss the influence of the entanglement interaction on the critical point of the expected first-order phase transition in the two-EoS model. In particular, for charge asymmetric matter, we analyze the local asymmetry of the u , d quarks as a function of quark concentration in the hadron-quark mixed phase during the phase transition. We finally propose some related observables that are possibly measurable in heavy-ion collision experiments.

  9. Phase diagram of QCD in a magnetic field

    NASA Astrophysics Data System (ADS)

    Andersen, Jens O.; Naylor, William R.; Tranberg, Anders

    2016-04-01

    Recent advances in our understanding of the phase structure and the phase transitions of hadronic matter in strong magnetic fields B and zero quark chemical potentials μf are reviewed in detail. Many aspects of QCD are described using low-energy effective theories and models such as the bag model, the hadron resonance gas model, chiral perturbation theory (χ PT ), the Nambu-Jona-Lasinio (NJL) model, the quark-meson (QM) model, and Polyakov-loop extended versions of the NJL and QM models. Their properties and applications are critically examined. This includes mean-field calculations as well as approaches beyond the mean-field approximation such as the functional renormalization group. Renormalization issues are discussed and the influence of the vacuum fluctuations on the chiral phase transition is pointed out. At T =0 , model calculations and lattice simulations predict magnetic catalysis: The quark condensate increases as a function of the magnetic field. This is covered in detail. Recent lattice results for the thermodynamics of non-Abelian gauge theories with emphasis on S U (2 )c and S U (3 )c are also discussed. In particular, inverse magnetic catalysis around the transition temperature Tc as a competition between contributions from valence quarks and sea quarks resulting in a decrease of Tc as a function of B is focused on. Finally, recent efforts to modify models in order to reproduce the behavior observed on the lattice are discussed.

  10. Recruitment Maneuver Does not Increase the Risk of Ventilator Induced Lung Injury

    PubMed Central

    Akıncı, İbrahim Özkan; Atalan, Korkut; Tuğrul, Simru; Özcan, Perihan Ergin; Yılmazbayhan, Dilek; Kıran, Bayram; Basel, Ahmet; Telci, Lutfi; Çakar, Nahit

    2013-01-01

    Background: Mechanical ventilation (MV) may induce lung injury. Aims: To assess and evaluate the role of different mechanical ventilation strategies on ventilator-induced lung injury (VILI) in comparison to a strategy which includes recruitment manoeuvre (RM). Study design: Randomized animal experiment. Methods: Thirty male Sprague-Dawley rats were anaesthetised, tracheostomised and divided into 5 groups randomly according to driving pressures; these were mechanically ventilated with following peak alveolar opening (Pao) and positive end-expiratory pressures (PEEP) for 1 hour: Group 15-0: 15 cmH2O Pao and 0 cmH2O PEEP; Group 30-10: 30 cmH2O Pao and 10 cmH2O PEEP; Group 30-5: 30 cmH2O Pao and 5 cmH2O PEEP; Group 30-5&RM: 30 cmH2O Pao and 5 cmH2O PEEP with additional 45 cmH2O CPAP for 30 seconds in every 15 minutes; Group 45-0: 45 cmH2O Pao and 0 cmH2O PEEP Before rats were sacrificed, blood samples were obtained for the evaluation of cytokine and chemokine levels; then, the lungs were subsequently processed for morphologic evaluation. Results: Oxygenation results were similar in all groups; however, the groups were lined as follows according to the increasing severity of morphometric evaluation parameters: Group 15-0: (0±0.009) < Group 30-10: (0±0.14) < Group 30-5&RM: (1±0.12) < Group 30-5: (1±0.16) < Group 45-0: (2±0.16). Besides, inflammatory responses were the lowest in 30-5&RM group compared to all other groups. TNF-α, IL-1β, IL-6, MCP-1 levels were significantly different between group 30-5&RM and group 15-0 vs. group 45-0 in each group. Conclusion: RM with low PEEP reduces the risk of ventilator-induced lung injury with a lower release of systemic inflammatory mediators in response to mechanical ventilation. PMID:25207105

  11. Mechanical Ventilation Augments Poly(I:C)-Induced Lung Injury via a WISP1-Integrin β3-Dependent Pathway in Mice

    PubMed Central

    Jin, Shuqing; Chen, Zhixia; Ding, Xibing; Zhao, Xiang; Jiang, Xi; Tong, Yao; Billiar, Timothy R; Li, Quan

    2016-01-01

    Mechanical ventilation can improve hypoxemia, but can also cause the so-called ventilator-induced lung injury (VILI). Polyinosinic:polycytidylic acid (poly(I:C)), an analogue of natural double-strand RNA virus, can induce lung inflammation. The purpose of this study was to determine whether moderate tidal volume mechanical ventilation (MTV) augments poly(I:C)-induced lung injury, and if so, the mechanism responsible for it. Two μg/g poly(I:C) were instilled intratracheally in C57BL/6J wide type (WT) mice. They were then randomized to MTV (10 ml/kg tidal volume) or spontaneous breathing. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected 4 h later for various measurements. Our results showed that MTV did not cause significant injury in normal lungs, but augmented poly(I:C)-induced lung injury. The expression level of WNT-induced secreted protein 1 (WISP1) was consistent with lung injury, and the amplification of lung injury by MTV could be alleviated by anti-WISP1 antibody treatment. MTV further increased poly(I:C)-induced integrin β3 expression in the lung. We performed coimmunoprecipitation, which showed there was an interaction between WISP1 and β3. WISP1 significantly increased poly(I:C)-induced TNF-α production in macrophages isolated from WT mice, but not in macrophages isolated from β3 knockout mice. Cotreatment with WISP1 and poly(I:C) markedly increased the phosphorylation of extracellular signal-related kinase (ERK) in macrophages. Pretreating macrophages with an ERK inhibitor, U0126, dose-dependently antagonized the synergistic effect of WISP1 on poly(I:C)-induced TNF-α release. In conclusion, MTV exaggerates poly(I:C)-induced lung injury in a WISP1- and integrin β3-dependent manner, involving, at least in part, the activation of the ERK pathway. The WISP1-integrin β3 pathway could be a novel therapeutic target. PMID:26772774

  12. Intrinsic and dynamically generated scalar meson states

    NASA Astrophysics Data System (ADS)

    Shakin, C. M.; Wang, Huangsheng

    2001-01-01

    Recent work by Maltman has given us confidence that our assignment of scalar meson states to various nonets based upon our generalized Nambu-Jona-Lasinio (NJL) model is correct. [For example, in our model the a0(980) and the f0(980) are in the same nonet as the K*0(1430).] In this work we make use of our model to provide a precise definition of ``preexisting'' resonances and ``dynamically generated'' resonances when considering various scalar mesons. [This distinction has been noted by Meissner in his characterization of the f0(400-1200) as nonpreexisting.] We define preexisting (or intrinsic) resonances as those that appear as singularities of the qq¯ T matrix and are in correspondence with qq¯ states bound in the confining field. [Additional singularities may be found when studying the T matrices describing π-π or π-K scattering, for example. Such features may be seen to arise, in part, from t-channel and u-channel ρ exchange in the case of π-π scattering, leading to the introduction of the σ(500-600). In addition, threshold effects in the qq¯ T matrix can give rise to significant broad cross section enhancements. The latter is, in part, responsible for the introduction of the κ(900) in a study of π-K scattering, for example.] We suggest that it is only the intrinsic resonances which correspond to qq¯ quark-model states, and it is only the intrinsic states that are to be used to form quark-model qq¯ nonets of states. [While the κ(900) and σ(500-600) could be placed in a nonet of dynamically generated states, it is unclear whether there is evidence that requires the introduction of other members of such a nonet.] In this work we show how the phenomena related to the introduction of the σ(500-600) and the κ(900) are generated in studies of π-π and π-K scattering, making use of our generalized Nambu-Jona-Lasinio model. We also calculate the decay constants for the a0 and K*0 mesons and compare our results with those obtained by Maltman. We find

  13. Neutrino emissivity in the quark-hadron mixed phase of neutron stars

    NASA Astrophysics Data System (ADS)

    Spinella, William M.; Weber, Fridolin; Contrera, Gustavo A.; Orsaria, Milva G.

    2016-03-01

    Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures (lesssim10^9 K) and quark fractions (lesssim 30% , and that contributions due to lattice vibrations are insignificant compared to static-lattice contributions.

  14. Analysis of Fusarium avenaceum metabolites produced during wet apple core rot.

    PubMed

    Sørensen, Jens Laurids; Phipps, Richard Kerry; Nielsen, Kristian Fog; Schroers, Hans-Josef; Frank, Jana; Thrane, Ulf

    2009-02-25

    Wet apple core rot (wACR) is a well-known disease of susceptible apple cultivars such as Gloster, Jona Gold, and Fuji. Investigations in apple orchards in Slovenia identified Fusarium avenaceum, a known producer of several mycotoxins, as the predominant causal agent of this disease. A LC-MS/MS method was developed for the simultaneous detection of thirteen F. avenaceum metabolites including moniliformin, acuminatopyrone, chrysogine, chlamydosporol, antibiotic Y, 2-amino-14,16-dimethyloctadecan-3-ol (2-AOD-3-ol), aurofusarin, and enniatins A, A1, B, B1, B2, and B3 from artificially and naturally infected apples. Levels of moniliformin, antibiotic Y, aurofusarin, and enniatins A, A1, B, and B1 were quantitatively examined in artificially inoculated and naturally infected apples, whereas the remaining metabolites were qualitatively detected. Metabolite production was examined in artificially inoculated apples after 3, 7, 14, and 21 days of incubation. Most metabolites were detected after 3 or 7 days and reached significantly high levels within 14 or 21 days. The highest levels of moniliformin, antibiotic Y, aurofusarin, and the combined sum of enniatins A, A1, B, and B1 were 7.3, 5.7, 152, and 12.7 microg g(-1), respectively. Seventeen of twenty naturally infected apples with wACR symptoms contained one or more of the metabolites. Fourteen of these apples contained moniliformin, antibiotic Y, aurofusarin, and enniatins in levels up to 2.9, 51, 167, and 3.9 microg g(-1), respectively. Acuminatopyrone, chrysogine, chlamydosporol, and 2-AOD-3-ol were detected in 4, 11, 4, and 10 apples, respectively. During wet apple core rot, F. avenaceum produced high amounts of mycotoxins, which may pose a risk for consumers of apple or processed apple products. PMID:19170495

  15. [Towards a new vaccine economy?].

    PubMed

    Poirot, P; Martin, J F

    1994-01-01

    When Jonas Salk announced in the mid-50s the availability of a new vaccine against poliomyelitis, the world had the impression that it was now controlling infectious diseases. In fact, the success of this vaccine has been considerable and although some innovations lead to the launch of vaccines against flu, measles, rubella or mumps, the world vaccine market remained remarkably stable till the mid-80s. However, since 1984 (launch of the hepatitis B vaccine) there have been very substantial changes and further change is expected in the next ten years in the world market. Today, big companies are making a concentrated supply: Pasteur Mérieux with its subsidiary Connaught, SmithKline Beecham who acquired the Belgian company RIT, and Merck & Co. who is joining its forces with Pasteur Mérieux. Medium sized and small companies remain and reflect the situation of the past, but must work hard to secure their long term existence eventhough the world demand is going to double before the year 2000. Very substantial technological innovations explain to a large extent the development of the supply: progress in molecular biology, and particularly genetic engineering, lead to recombinant vaccines of which hepatitis B is the best example with worldwide sales in the range of $600 million a year. Similarly, conjugation technologies have allowed the development of new vaccines against meningitis, particularly Haemophilus influenzae type b. More recently, an efficacious vaccine against hepatitis A has been launched and many new products will be marketed in the next years against herpes, Lyme disease, and agents of other meningitis, etc.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7921683

  16. The Ig-ITIM superfamily member PECAM-1 regulates the "outside-in" signaling properties of integrin alpha(IIb)beta3 in platelets.

    PubMed

    Wee, Janet L; Jackson, Denise E

    2005-12-01

    Previous studies have implicated the immunoglobulin (Ig)-immunoreceptor tyrosine-based inhibitory motif (ITIM) superfamily member platelet endothelial cell adhesion molecule-1 (PECAM-1) in the regulation of integrin function. While PECAM-1 has been demonstrated to play a role as an inhibitory coreceptor of immunoreceptor tyrosine-based activation motif (ITAM)-associated Fcgamma receptor IIa (FcgammaRIIa) and glycoprotein VI (GPVI)/FcR gamma-chain signaling pathways in platelets, its physiologic role in integrin alpha(IIb)beta3-mediated platelet function is unclear. In this study, we investigate the functional importance of PECAM-1 in murine platelets. Using PECAM-1-deficient mice, we show that the platelets have impaired "outside-in" integrin alpha(IIb)beta3 signaling with impaired platelet spreading on fibrinogen, failure to retract fibrin clots in vitro, and reduced tyrosine phosphorylation of focal adhesion kinase p125 (125FAK) following integrin alpha(IIb)beta3-mediated platelet aggregation. This functional integrin alpha(IIb)beta3 defect could not be attributed to altered expression of integrin alpha(IIb)beta3. PECAM-1-/- platelets displayed normal platelet alpha granule secretion, normal platelet aggregation to protease-activated receptor-4 (PAR-4), adenosine diphosphate (ADP), and calcium ionophore, and static platelet adhesion. In addition, PECAM-1-/- platelets displayed normal "inside-out" integrin alpha(IIb)beta3 signaling properties as demonstrated by normal agonist-induced binding of soluble fluoroscein isothiocyanate (FITC)-fibrinogen, JON/A antibody binding, and increases in cytosolic-free calcium and inositol (1,4,5)P3 triphosphate (IP3) levels. This study provides direct evidence that PECAM-1 is essential for normal integrin alpha(IIb)beta3-mediated platelet function and that disruption of PECAM-1 induced a moderate "outsidein" integrin alpha(IIb)beta3 signaling defect. PMID:16081692

  17. Hybrid Stars in the Light of the Massive Pulsar PSR J1614-2230

    NASA Astrophysics Data System (ADS)

    Lenzi, C. H.; Lugones, G.

    2012-11-01

    We perform a systematic study of hybrid star configurations using several parameterizations of a relativistic mean-field hadronic equation of state (EoS) and the Nambu-Jona-Lasinio (NJL) model for three-flavor quark matter. For the hadronic phase we use the stiff GM1 and TM1 parameterizations, as well as the very stiff NL3 model. In the NJL Lagrangian we include scalar, vector, and 't Hooft interactions. The vector coupling constant gv is treated as a free parameter. We also consider that there is a split between the deconfinement and the chiral phase transitions which is controlled by changing the conventional value of the vacuum pressure -Ω0 in the NJL thermodynamic potential by -(Ω0 + δΩ0), with δΩ0 a free parameter. We find that, as we increase the value of δΩ0, hybrid stars have a larger maximum mass but are less stable, i.e., hybrid configurations are stable within a smaller range of central densities. For large enough δΩ0, stable hybrid configurations are not possible at all. The effect of increasing the coupling constant gv is very similar. We show that stable hybrid configurations with a maximum mass larger than the observed mass of the pulsar PSR J1614-2230 are possible for a large region of the parameter space of gv and δΩ0 provided the hadronic EoS contains nucleons only. When the baryon octet is included in the hadronic phase, only a very small region of the parameter space allows an explanation of the mass of PSR J1614-2230. We compare our results with previous calculations of hybrid stars within the NJL model. We show that it is possible to obtain stable hybrid configurations also in the case δΩ0 = 0 that corresponds to the conventional NJL model for which the pressure and density vanish at zero temperature and chemical potential.

  18. Chiral quark dynamics and topological charge: The role of the Ramond-Ramond U(1) gauge field in holographic QCD

    NASA Astrophysics Data System (ADS)

    Thacker, H. B.; Xiong, Chi; Kamat, Ajinkya S.

    2011-11-01

    The Witten-Sakai-Sugimoto construction of holographic QCD in terms of D4 color branes and D8 flavor branes in type IIA string theory is used to investigate the role of topological charge in the chiral dynamics of quarks in QCD. The QCD theta term arises from a compactified five-dimensional Chern-Simons term on the D4 branes. This term couples the QCD topological charge to the Ramond-Ramond (RR) U(1) gauge field of type IIA string theory. For large Nc the contribution of instantons (D0 branes) is suppressed, and the nonzero topological susceptibility of pure-glue QCD is attributed to the presence of D6 branes, which constitute magnetic sources of the RR gauge field. The topological charge of QCD is required, by an anomaly inflow argument, to coincide in space-time with the intersection of the D6 branes and the D4 color branes. This clarifies the relation between D6 branes and the coherent, codimension-one topological charge membranes observed in QCD Monte Carlo calculations. Using open-string/closed-string duality, we interpret a quark loop (represented by a D4-D8 open-string loop) in terms of closed-string exchange between color and flavor branes. The role of the RR gauge field in quark-antiquark annihilation processes is discussed. RR exchange in the s-channel generates a 4-quark contact term which produces an η' mass insertion and provides an explanation for the observed spin-parity structure of the Okubo-Zweig-Iizuka rule. The (log⁡DetU)2 form of the U(1) anomaly emerges naturally. RR exchange in the t-channel of the qq¯ scattering amplitude produces a Nambu-Jona-Lasinio interaction which may provide a mechanism for spontaneous breaking of SU(Nf)×SU(Nf).

  19. Gaussian process test for high-throughput sequencing time series: application to experimental evolution

    PubMed Central

    Topa, Hande; Jónás, Ágnes; Kofler, Robert; Kosiol, Carolin; Honkela, Antti

    2015-01-01

    Motivation: Recent advances in high-throughput sequencing (HTS) have made it possible to monitor genomes in great detail. New experiments not only use HTS to measure genomic features at one time point but also monitor them changing over time with the aim of identifying significant changes in their abundance. In population genetics, for example, allele frequencies are monitored over time to detect significant frequency changes that indicate selection pressures. Previous attempts at analyzing data from HTS experiments have been limited as they could not simultaneously include data at intermediate time points, replicate experiments and sources of uncertainty specific to HTS such as sequencing depth. Results: We present the beta-binomial Gaussian process model for ranking features with significant non-random variation in abundance over time. The features are assumed to represent proportions, such as proportion of an alternative allele in a population. We use the beta-binomial model to capture the uncertainty arising from finite sequencing depth and combine it with a Gaussian process model over the time series. In simulations that mimic the features of experimental evolution data, the proposed method clearly outperforms classical testing in average precision of finding selected alleles. We also present simulations exploring different experimental design choices and results on real data from Drosophila experimental evolution experiment in temperature adaptation. Availability and implementation: R software implementing the test is available at https://github.com/handetopa/BBGP. Contact: hande.topa@aalto.fi, agnes.jonas@vetmeduni.ac.at, carolin.kosiol@vetmeduni.ac.at, antti.honkela@hiit.fi Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25614471

  20. Dok-1 negatively regulates platelet integrin αIIbβ3 outside-in signalling and inhibits thrombosis in mice.

    PubMed

    Niki, Masaru; Nayak, Manasa K; Jin, Hong; Bhasin, Neha; Plow, Edward F; Pandolfi, Pier Paolo; Rothman, Paul B; Chauhan, Anil K; Lentz, Steven R

    2016-05-01

    Adaptor proteins play a critical role in the assembly of signalling complexes after engagement of platelet receptors by agonists such as collagen, ADP and thrombin. Recently, using proteomics, the Dok (downstream of tyrosine kinase) adapter proteins were identified in human and mouse platelets. In vitro studies suggest that Dok-1 binds to platelet integrin β3, but the underlying effects of Dok-1 on αIIbβ3 signalling, platelet activation and thrombosis remain to be elucidated. In the present study, using Dok-1-deficient (Dok-1-/-) mice, we determined the phenotypic role of Dok-1 in αIIbβ3 signalling. We found that platelets from Dok-1-/- mice displayed normal aggregation, activation of αIIbβ3 (assessed by binding of JON/A), P-selectin surface expression (assessed by anti-CD62P), and soluble fibrinogen binding. These findings indicate that Dok-1 does not affect "inside-out" platelet signalling. Compared with platelets from wild-type (WT) mice, platelets from Dok-1-/- mice exhibited increased clot retraction (p < 0.05 vs WT), increased PLCγ2 phosphorylation, and enhanced spreading on fibrinogen after thrombin stimulation (p < 0.01 vs WT), demonstrating that Dok-1 negatively regulates αIIbβ3 "outside-in" signalling. Finally, we found that Dok-1-/- mice exhibited significantly shortened bleeding times and accelerated carotid artery thrombosis in response to photochemical injury (p < 0.05 vs WT mice). We conclude that Dok-1 modulates thrombosis and haemostasis by negatively regulating αIIbβ3 outside-in signalling. PMID:26790499

  1. Role of diquark correlations and the pion cloud in nucleon elastic form factors

    NASA Astrophysics Data System (ADS)

    Cloët, Ian C.; Bentz, Wolfgang; Thomas, Anthony W.

    2014-10-01

    Electromagnetic form factors of the nucleon in the spacelike region are investigated within the framework of a covariant and confining Nambu-Jona-Lasinio model. The bound-state amplitude of the nucleon is obtained as the solution of a relativistic Faddeev equation, where diquark correlations appear naturally as a consequence of the strong coupling in the color 3¯ qq channel. Pion degrees of freedom are included as a perturbation to the "quark-core" contribution obtained using the Poincaré covariant Faddeev amplitude. While no model parameters are fit to form-factor data, excellent agreement is obtained with the empirical nucleon form factors (including the magnetic moments and radii) where pion loop corrections play a critical role for Q2≲1GeV2. Using charge symmetry, the nucleon form factors can be expressed as proton quark sector form factors. The latter are studied in detail, leading, for example, to the conclusion that the d-quark sector of the Dirac form factor is much softer than the u-quark sector, a consequence of the dominance of scalar diquark correlations in the proton wave function. On the other hand, for the proton quark sector Pauli form factors we find that the effect of the pion cloud and axial-vector diquark correlations overcomes the effect of scalar diquark dominance, leading to a larger d-quark anomalous magnetic moment and a form factor in the u-quark sector that is slightly softer than in the d-quark sector.

  2. Survival of charged ρ condensation at high temperature and density

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Yu, Lang; Huang, Mei

    2016-02-01

    The charged vector ρ mesons in the presence of external magnetic fields at finite temperature T and chemical potential μ have been investigated in the framework of the Nambu-Jona-Lasinio model. We compute the masses of charged ρ mesons numerically as a function of the magnetic field for different values of temperature and chemical potential. The self-energy of the ρ meson contains the quark-loop contribution, i.e. the leading order contribution in 1/Nc expansion. The charged ρ meson mass decreases with the magnetic field and drops to zero at a critical magnetic field eBc, which indicates that the charged vector meson condensation, i.e. the electromagnetic superconductor can be induced above the critical magnetic field. Surprisingly, it is found that the charged ρ condensation can even survive at high temperature and density. At zero temperature, the critical magnetic field just increases slightly with the chemical potential, which indicates that charged ρ condensation might occur inside compact stars. At zero density, in the temperature range 0.2-0.5 GeV, the critical magnetic field for charged ρ condensation is in the range of 0.2-0.6 GeV2, which indicates that a high temperature electromagnetic superconductor might be created at LHC. Supported by the NSFC (11275213, 11261130311) (CRC 110 by DFG and NSFC), CAS Key Project (KJCX2-EW-N01), and Youth Innovation Promotion Association of CAS. L.Yu is Partially Supported by China Postdoctoral Science Foundation (2014M550841)

  3. Relationship between morphology and glass-rubber relaxation in solvent-crystallized poly(aryl ether ketones)

    SciTech Connect

    Kalika, D.S.; Gibson, D.G.; Register, R.A.; Quiram, D.J.

    1996-12-31

    The relationship between crystal lamellar structure and glass-rubber relaxation behavior has been examined for solvent- and thermally-crystallized poly (aryl ether ketones). The thermal crystallization of poly (ether ether ketone) [PEEK] leads to a positive offset in the glass transition temperature of 10{degrees}C to 15{degrees}C as compared to a wholly-amorphous (quenched) sample owing to the constraint imposed on the amorphous PEEK segments by the crystallites. The degree of constraint is a function of the crystallization conditions, with less restrictive conditions (e.g., higher cold-crystallization temperatures) leading to a progressive decrease in T{sub g}. Small-angle X-ray scattering measurements reported by Jonas and Legras indicate an inverse relationship between amorphous interlayer thickness and glass transition temperature for thermally-crystallized PEEK specimens, with higher crystallization temperatures resulting in a larger interlayer spacing and correspondingly lower T{sub g}. Solvent-crystallized PEEK samples display relaxation temperatures which are significantly higher as compared to thermally-crystallized PEEK of comparable bulk crystallinity. SAXS measurements reveal a much smaller crystal long spacing (d) for the solvent-crystallized samples. The relationship between T{sub g} and long spacing is consistent with a linear extrapolation of the thermal crystallization values. Annealing of the solvent-crystallized specimens at 300{degrees}C leads to crystal reorganization and an increase in the measured long spacing, with a corresponding decrease in T{sub g}. Results for solvent-crystallized poly (ether ketone ketone) [PEKK] are similar to those obtained for PEEK, with a considerable offset in T{sub g} measured for all samples exposed to solvent crystallization.

  4. Jeff Levin, MPH, PhD. The power of love. Interview by Bonnie Horrigan.

    PubMed

    Levin, J

    1999-07-01

    Jeff Levin is an epidemiologist and writer living in Kansas. He was trained in religion, sociology, public health, preventive medicine, and gerontology at Duke University, the University of North Carolina, the University of Texas Medical Branch, and the University of Michigan. From 1989 to 1997 he served on the faculty of the Department of Family and Community Medicine at Eastern Virginia Medical School in Norfolk, Va. Dr Levin pioneered basic research on the epidemiology of religion. He has been funded by several National Institute of Health (NIH) grants, totaling more than $1 million in support. He has also received funding from private sources including the American Medical Association and the Institute of Noetic Sciences. Dr Levin is a senior research fellow of the National Institute for Healthcare Research; an advisory board member of the Center on Aging, Religion, and Spirituality; and past president of the International Society for the Study of Subtle Energies and Energy Medicine. He has been chair of the NIH Working Group on Quantitative Methods in Alternative Medicine, is a former member of the NIH Workgroup on Measures of Religiousness and Spirituality, and is a member of the editorial boards of several peer-reviewed scientific journals including Alternative Therapies. Dr Levin is the author of more than 110 scholarly publications, including 5 books. These include his edited book Religion in Aging and Health (Sage Publications); the newly published Essentials of Complementary and Alternative Medicine (Lippincott, Williams & Wilkins), which he edited with Dr Wayne Jonas; and the forthcoming God, Faith, and Health (John Wiley & Sons). Alternative Therapies interviewed Dr Levin at his home in Topeka, Kan, where he lives with his wife, Dr Lea Steele Levin. PMID:10394678

  5. Effective field theories of baryons and mesons, or, what do quarks do?

    SciTech Connect

    Keaton, G.L.

    1995-06-26

    This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective field theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N{sup 2}. To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark.

  6. Wdr1-Dependent Actin Reorganization in Platelet Activation.

    PubMed

    Dasgupta, Swapan K; Le, Anhquyen; Da, Qi; Cruz, Miguel; Rumbaut, Rolando E; Thiagarajan, Perumal

    2016-01-01

    In resting platelets, the integrin αIIbβ3 is present in a low-affinity "bent" state. During platelet aggregation, intracytoplasmic signals induce conformational changes (inside-out signaling) that result in a "swung-out" conformation competent to bind ligands such as fibrinogen. The cytoskeleton plays an essential role in αIIbβ3 activation. We investigated the role of the actin interacting protein Wdr1 in αIIbβ3 activation. Wdr1-hypomorphic mice had a prolonged bleeding time (> 10 minutes) compared to that of wild-type mice (2.1 ± 0.7 minutes). Their platelets had impaired aggregation to collagen and thrombin. In a FeCl3 induced carotid artery thrombosis model, vessel occlusion in Wdr1-hypomorphic mice was prolonged significantly compared to wild-type mice (9.0 ± 10.5 minutes versus 5.8 ± 12.6 minutes (p = 0.041). Activation-induced binding of JON/A (a conformation-specific antibody to activated αIIbβ3) was significantly less in Wdr1-hypomorphic platelets at various concentrations of collagen, indicating impaired inside-out activation of αIIbβ3, despite a normal calcium response. Actin turnover, assessed by measuring F-actin and G-actin ratios during collagen- and thrombin-induced platelet aggregation, was highly impaired in Wdr1-hypomorphic platelets. Furthermore, talin failed to redistribute and translocate to the cytoskeleton following activation in Wdr1-hypomorphic platelets. These studies show that Wdr1 is essential for talin-induced activation of αIIbβ3 during platelet activation. PMID:27627652

  7. Anisotropic propagator for the Goldstone modes in color-flavor locked phase in the presence of a magnetic field

    NASA Astrophysics Data System (ADS)

    Sen, Srimoyee

    2015-07-01

    We consider the phase diagram of QCD at very high baryon density and at zero temperature in the presence of a strong magnetic field. The state of matter at such high densities and low temperatures is believed to be a phase known as the color-flavor locked phase which breaks color and electromagnetic gauge invariance, leaving a linear combination of them, denoted as U (1 )e m ˜ , unbroken. Of the nine quarks (three flavors and three colors), five are neutral under this unbroken generator and four are oppositely charged (two with a charge of +1 and two with -1 ). In the presence of a magnetic field corresponding to U (1 )em ˜, however, the properties of the condensate change and a new phase known as the magnetic color-flavor locked (MCFL) phase is realized. This phase breaks an approximate S U (3 )C×S U (2 )L×S U (2 )R×U (1 )B×U (1 )A- symmetry of the Lagrangian to S U (2 )C+L +R×U (1 )em ˜ giving rise to six Goldstone modes, five of which are pseudo Goldstone modes. These Goldstone modes are composed of excitations that correspond to both neutral quarks and charged quarks. Hence it is natural to expect that the propagators of these Goldstone modes are affected in the presence of a magnetic field, and their speed becomes considerably anisotropic. Although this anisotropy is self-evident from symmetry arguments, it has not been quantified yet. We calculate this anisotropy in the speed of the Goldstone modes using a Nambu-Jona-Lasinio model type of interaction between the quarks and comment on the impact of such anisotropic modes on transport properties of the MCFL phase.

  8. Understanding QCD at high density from a Z3 -symmetric QCD-like theory

    NASA Astrophysics Data System (ADS)

    Kouno, Hiroaki; Kashiwa, Kouji; Takahashi, Junichi; Misumi, Tatsuhiro; Yahiro, Masanobu

    2016-03-01

    We investigate QCD at large μ /T by using Z3-symmetric S U (3 ) gauge theory, where μ is the quark-number chemical potential and T is temperature. We impose the flavor-dependent twist boundary condition on quarks in QCD. This QCD-like theory has the twist angle θ as a parameter, and agrees with QCD when θ =0 and becomes symmetric when θ =2 π /3 . For both QCD and the Z3-symmetric S U (3 ) gauge theory, the phase diagram is drawn in μ -T plane with the Polyakov-loop extended Nambu-Jona-Lasinio model. In the Z3-symmetric S U (3 ) gauge theory, the Polyakov loop φ is zero in the confined phase appearing at T ≲200 MeV and μ ≲300 MeV . The perfectly confined phase never coexists with the color superconducting (CSC) phase, since finite diquark condensate in the CSC phase breaks Z3 symmetry and then makes φ finite. When μ ≳300 MeV , the CSC phase is more stable than the perfectly confined phase at T ≲100 MeV . Meanwhile, the chiral symmetry can be broken in the perfectly confined phase, since the chiral condensate is Z3 invariant. Consequently, the perfectly confined phase is divided into the perfectly confined phase without chiral symmetry restoration in a region of μ ≲300 MeV and T ≲200 MeV and the perfectly confined phase with chiral symmetry restoration in a region of μ ≳300 MeV and 100 ≲T ≲200 MeV . At low temperature, the basic phase structure of Z3-symmetric QCD-like theory remains in QCD. Properties of the sign problem in Z3-symmetric theory are also discussed. We discuss a numerical framework to evaluate observables at θ =0 from those at θ =2 π /3 .

  9. Complex spectrum of finite-density lattice QCD with static quarks at strong coupling

    NASA Astrophysics Data System (ADS)

    Nishimura, Hiromichi; Ogilvie, Michael C.; Pangeni, Kamal

    2016-05-01

    We calculate the spectrum of transfer matrix eigenvalues associated with Polyakov loops in finite-density lattice QCD with static quarks. These eigenvalues determine the spatial behavior of Polyakov loop correlation functions. Our results are valid for all values of the gauge coupling in 1 +1 dimensions and in the strong-coupling region for any number of dimensions. When the quark chemical potential μ is nonzero, the spatial transfer matrix Ts is non-Hermitian. The appearance of complex eigenvalues in Ts is a manifestation of the sign problem in finite-density QCD. The invariance of finite-density QCD under the combined action of charge conjugation C and complex conjugation K implies that the eigenvalues of Ts are either real or part of a complex pair. Calculation of the spectrum confirms the existence of complex pairs in much of the temperature-chemical potential plane. Many features of the spectrum for static quarks are determined by a particle-hole symmetry. For μ that is small compared to the quark mass M , we typically find real eigenvalues for the lowest-lying states. At somewhat larger values of μ , pairs of eigenvalues may form complex-conjugate pairs, leading to damped oscillatory behavior in Polyakov loop correlation functions. However, near μ =M , the low-lying spectrum becomes real again. This is a direct consequence of the approximate particle-hole symmetry at μ =M for heavy quarks. This behavior of the eigenvalues should be observable in lattice simulations and can be used as a test of lattice algorithms. Our results provide independent confirmation of results we have previously obtained in Polyakov-Nambu-Jona-Lasinio models using complex saddle points.

  10. MITIE: Simultaneous RNA-Seq-based transcript identification and quantification in multiple samples

    PubMed Central

    Behr, Jonas; Kahles, André; Zhong, Yi; Sreedharan, Vipin T.; Drewe, Philipp; Rätsch, Gunnar

    2013-01-01

    Motivation: High-throughput sequencing of mRNA (RNA-Seq) has led to tremendous improvements in the detection of expressed genes and reconstruction of RNA transcripts. However, the extensive dynamic range of gene expression, technical limitations and biases, as well as the observed complexity of the transcriptional landscape, pose profound computational challenges for transcriptome reconstruction. Results: We present the novel framework MITIE (Mixed Integer Transcript IdEntification) for simultaneous transcript reconstruction and quantification. We define a likelihood function based on the negative binomial distribution, use a regularization approach to select a few transcripts collectively explaining the observed read data and show how to find the optimal solution using Mixed Integer Programming. MITIE can (i) take advantage of known transcripts, (ii) reconstruct and quantify transcripts simultaneously in multiple samples, and (iii) resolve the location of multi-mapping reads. It is designed for genome- and assembly-based transcriptome reconstruction. We present an extensive study based on realistic simulated RNA-Seq data. When compared with state-of-the-art approaches, MITIE proves to be significantly more sensitive and overall more accurate. Moreover, MITIE yields substantial performance gains when used with multiple samples. We applied our system to 38 Drosophila melanogaster modENCODE RNA-Seq libraries and estimated the sensitivity of reconstructing omitted transcript annotations and the specificity with respect to annotated transcripts. Our results corroborate that a well-motivated objective paired with appropriate optimization techniques lead to significant improvements over the state-of-the-art in transcriptome reconstruction. Availability: MITIE is implemented in C++ and is available from http://bioweb.me/mitie under the GPL license. Contact: Jonas_Behr@web.de and raetsch@cbio.mskcc.org Supplementary information: Supplementary data are available at

  11. Effective Field Theories for Hot and Dense Matter

    NASA Astrophysics Data System (ADS)

    Blaschke, D.

    2010-10-01

    The lecture is divided in two parts. The first one deals with an introduction to the physics of hot, dense many-particle systems in quantum field theory [1, 2]. The basics of the path integral approach to the partition function are explained for the example of chiral quark models. The QCD phase diagram is discussed in the meanfield approximation while QCD bound states in the medium are treated in the rainbow-ladder approximation (Gaussian fluctuations). Special emphasis is devoted to the discussion of the Mott effect, i.e. the transition of bound states to unbound, but resonant scattering states in the continnum under the influence of compression and heating of the system. Three examples are given: (1) the QCD model phase diagram with chiral symmetry ¨ restoration and color superconductivity [3], (2) the Schrodinger equation for heavy-quarkonia [4], and (2) Pions [5] as well as Kaons and D-mesons in the finite-temperature Bethe-Salpeter equation [6]. We discuss recent applications of this quantum field theoretical approach to hot and dense quark matter for a description of anomalous J/ψ supression in heavy-ion collisions [7] and for the structure and cooling of compact stars with quark matter interiors [8]. The second part provides a detailed introduction to the Polyakov-loop Nambu-Jona-Lasinio model [9] for thermodynamics and mesonic correlations [10] in the phase diagram of quark matter. Important relationships of low-energy QCD like the Gell-Mann-Oakes-Renner relation are generalized to finite temperatures. The effect of including the coupling to the Polyakov-loop potential on the phase diagram and mesonic correlations is discussed. An outlook is given to effects of nonlocality of the interactions [11] and of mesonic correlations in the medium [12] which go beyond the meanfield description.

  12. The golden jubilee of vaccination against poliomyelitis.

    PubMed

    John, T Jacob

    2004-01-01

    Inactivated poliovirus vaccine (IPV), developed in the USA by Jonas Salk in the early 1950s, was field tested in 1954, and found to be safe and effective. The year 2004 marks the golden jubilee of this breakthrough. From 1955 IPV was used extensively in the US and polio incidence declined by more than 95 per cent. However, in 1962, when oral poliovirus vaccine (OPV) became available, the national policy was shifted to its exclusive use, for reasons other than science and economics. The World Health Organisation (WHO) also adopted the policy of the exclusive use of OPV in developing countries. Thus IPV fell into disrepute in much of the world, while Northern European countries continued to use it. New research led to improving its potency, reducing its manufacturing costs and combining it with the diphtheria-tetanus-pertussis (DTP) vaccine to simplify its administration and reduce programmatic costs. All countries that chose to persist with IPV eliminated poliovirus circulation without OPV-induced polio or the risk of live vaccine viruses reverting to wild-like nature. IPV is highly immunogenic, confers mucosal immunity and exerts herd protective effect, all qualities of a good vaccine. It can be used in harmony with the extendend programme on immunization (EPI) schedule of infant immunisation with DTP, thus reducing programmatic costs. During the last ten years IPV has once again regained its popularity and some 25 industrialised countries use it exclusively. The demand is increasing from other countries and the supply has not caught up, leaving market forces to dictate the sale price of IPV. Anticipating such a turn of events India had launched its own IPV manufacturing programme in 1987, but the project was closed in 1992. Today it is not clear if we can complete the job of global polio eradication without IPV, on account of the genetic instability of OPV and the consequent tendency of vaccine viruses to revert to wild-like properties. The option to use IPV is

  13. Poliomyelitis and the control programme.

    PubMed

    Basu, R N

    1985-01-01

    Poliomyelitis, an acute infectious disease which chiefly affects the central nervous system, is included in the list of 20 communicable diseases which are to be reported monthly by all institutions to the State Bureau of Health Intelligence for onward transmission to India's Central Bureau of Health Intelligence (CBHI). The reported number of 17,441 cases of poliomyelitis (annual average) since 1974 fail to reflect the magnitude of the problem in India. Directorate General of Health Services (DHGS) in collaboration with the State health authorities organized sample lameness surveys of children 5-9 years in the community during 1981-82. Poliomyelitis was found to be the major cause of lameness in children 5-9 years (64.5%). Data on admission of poliomyelitis cases from selected hospital in metropolitan cities were collected. All the hospitals reported maximum number of polio cases (more than 78%) below the age of 2 years. This data reinforce the importance of improving vaccination coverage in the age group most affected. High incidence of poliomyelitis (45% of the cases) were observed during July, August, and September, corresponding to the well demarcated monsoon season. This suggests a need to intensify immunization coverage during the low polio incidence period, namely, November to April. Polio vaccine was introduced in the national immunization program in 1980. The schedule recommends 3 doses of oral polio vaccine (OPV), starting from the age of 3 months with intervals not less than 1 month. DPT and polio vaccine are administered to the child at the same time. 1 booster dose of OPV is recommended 12-18 months later. The live attenuated OPV, not produced in India is used in the national program. The requirement of the program is met by import of bulk concentrated vaccine separately for type 1, type 2, and type 3. Then, it is diluted, blended, and ampouled by Haffkine Biopharmaceutical Corporation, Ltd. The recent visit of Dr. Jonas Salk has raised the issue of

  14. The influence of solution composition and grain boundaries on the replacement of calcite by dolomite

    NASA Astrophysics Data System (ADS)

    Moraila Martinez, Teresita de Jesus; Putnis, Christine V.; Putnis, Andrew

    2016-04-01

    microreactors during reactive fluid flow: experimental dolomitization of a calcite marble. Contributions to Mineralogy and Petrology. 168:1045. 2. Jonas L., Müller T., Dohmen R., Baumgartner L., Putlitz B. (2015). Transport-controlled hydrothermal replacement of calcite by Mg-carbonates. Geology. doi:10.1130/G36934.1 3. Kaczmarek S.E., Sibley D.F., (2011). On the evolution of dolomite stoichiometry and cation order during high-temperature synthesis experiments: An alternative model for geochemical evolution of natural dolomites. Sedimentary Geology. 246, 30-40.

  15. Phase diagram of chiral quark matter: From weakly to strongly coupled Fulde-Ferrell phase

    SciTech Connect

    Sedrakian, Armen; Rischke, Dirk H.

    2009-10-01

    We calculate the phase diagram of two-flavor quark matter within the Nambu-Jona-Lasinio (NJL) model in the temperature-flavor asymmetry plane in the case where there are three competing phases: the homogeneous Bardeen-Cooper-Schrieffer (BCS) phase, the unpaired phase, and a phase with broken spatial symmetry, which is here taken to be the counterpart of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in condensed matter physics. The system belongs to the universality class of paramagnetic-ferromagnetic-helical systems, and therefore contains a tricritical Lifshitz point in its phase diagram, where the momentum scale characterizing the breaking of translational invariance has a critical exponent of 1/2 to leading order. Upon varying the coupling constant of the theory we find that in weak coupling, the FFLO phase is favored at arbitrary flavor asymmetries for sufficiently low temperatures; at intermediate coupling its occupancy domain is shifted towards larger asymmetries. Strong coupling features a new regime of an inhomogeneous FF state, which we identify with a current-carrying Bose-Einstein condensate of tightly bound up and down quarks. The temperature and asymmetry dependence of the gap function is studied. It is shown that the anomalous temperature dependence of the gap in the homogeneous, flavor-asymmetric phase is transformed into a normal dependence (self-similar to the BCS phase) at arbitrary coupling, once the FF phase is allowed for. We analyze the occupation numbers and the Cooper-pair wave function and show that when the condensate momentum is orthogonal to the particle momentum the minority component contains a blocking region (breach) around the Fermi sphere in the weak-coupling limit, which engulfs more low-momentum modes as the coupling is increased, and eventually leads to a topological change in strong coupling, where the minority Fermi sphere contains either two occupied strips or an empty sphere. For nonorthogonal momenta, the blocking

  16. Reader-Centered Technical Writing

    NASA Astrophysics Data System (ADS)

    Narayanan, M.

    2012-12-01

    an old schema. This reinforces basic engineering and mathematical design concepts. Accommodation: Here, it may work in a different manner. Writers may have to accommodate an old schema to a new object. This helps engineers to focus more on applications. Adaptation: Assimilation and accommodation are the two sides of adaptation, Jean Piaget's term for what most of us would call learning. Mathematical design concepts generated by students should be suitable for creative engineering applications. References : Phillips, D. C. and Soltis, Jonas F. (2003) "Piagetian Structures and Psychological Constructivism," in Perspectives on Learning (4th edition). New York: Teachers College Press. Salvo, Michael J. (2001). Ethics of Engagement: User-Centered Design and Rhetorical Methodology. Technical Communication Quarterly Volume 10, Issue 3, 2001. pages 273-290. http://www.ship.edu/~cgboeree/piaget.html http://owl.english.purdue.edu/owl/resource/624/01/

  17. Temporal Variability of Methane Flares on the Cascadia Margin Imaged with Swath Bathymetric Data (Ancillary Data to Cascadia Initiative Cruise AT26-02)

    NASA Astrophysics Data System (ADS)

    Trehu, A. M.

    2013-12-01

    Livelybrooks (Un. of Oregon), undergraduates participating in summer research programs at (Elizabeth Davis, Indiana Un. and Oregon State Un. REU program in Oceanography; David Clemens-Sewall, Dartmouth College and IRIS intern), community college students and faculty (Haley Domer, Portland CC; Jonas Cervantes and Greg Mulder, Linn-Benton CC), and graduate students and scientists who had applied to sailed on a Cascadia Initiative cruise (Bridget Hass, Oregon State Un.; Katherine Kirk, Cornell Un. and WHOI; Anton Ypma, Western Washington Un.; Lexi Black, CA State Un. Northridge; Samantha Black, College of Charleston). WHOI marine technician Rob Hagg and MATE Intern Arianna Johns also contributed significantly to this effort.

  18. Psychosomatic medicine and the philosophy of life.

    PubMed

    Schwartz, Michael A; Wiggins, Osborne P

    2010-01-01

    Basing ourselves on the writings of Hans Jonas, we offer to psychosomatic medicine a philosophy of life that surmounts the mind-body dualism which has plagued Western thought since the origins of modern science in seventeenth century Europe. Any present-day account of reality must draw upon everything we know about the living and the non-living. Since we are living beings ourselves, we know what it means to be alive from our own first-hand experience. Therefore, our philosophy of life, in addition to starting with what empirical science tells us about inorganic and organic reality, must also begin from our own direct experience of life in ourselves and in others; it can then show how the two meet in the living being. Since life is ultimately one reality, our theory must reintegrate psyche with soma such that no component of the whole is short-changed, neither the objective nor the subjective. In this essay, we lay out the foundational components of such a theory by clarifying the defining features of living beings as polarities. We describe three such polarities: 1) Being vs. non-being: Always threatened by non-being, the organism must constantly re-assert its being through its own activity. 2) World-relatedness vs. self-enclosure: Living beings are both enclosed with themselves, defined by the boundaries that separate them from their environment, while they are also ceaselessly reaching out to their environment and engaging in transactions with it. 3) Dependence vs. independence: Living beings are both dependent on the material components that constitute them at any given moment and independent of any particular groupings of these components over time.We then discuss important features of the polarities of life: Metabolism; organic structure; enclosure by a semi-permeable membrane; distinction between "self" and "other"; autonomy; neediness; teleology; sensitivity; values. Moral needs and values already arise at the most basic levels of life, even if only human

  19. Psychosomatic medicine and the philosophy of life

    PubMed Central

    2010-01-01

    Basing ourselves on the writings of Hans Jonas, we offer to psychosomatic medicine a philosophy of life that surmounts the mind-body dualism which has plagued Western thought since the origins of modern science in seventeenth century Europe. Any present-day account of reality must draw upon everything we know about the living and the non-living. Since we are living beings ourselves, we know what it means to be alive from our own first-hand experience. Therefore, our philosophy of life, in addition to starting with what empirical science tells us about inorganic and organic reality, must also begin from our own direct experience of life in ourselves and in others; it can then show how the two meet in the living being. Since life is ultimately one reality, our theory must reintegrate psyche with soma such that no component of the whole is short-changed, neither the objective nor the subjective. In this essay, we lay out the foundational components of such a theory by clarifying the defining features of living beings as polarities. We describe three such polarities: 1) Being vs. non-being: Always threatened by non-being, the organism must constantly re-assert its being through its own activity. 2) World-relatedness vs. self-enclosure: Living beings are both enclosed with themselves, defined by the boundaries that separate them from their environment, while they are also ceaselessly reaching out to their environment and engaging in transactions with it. 3) Dependence vs. independence: Living beings are both dependent on the material components that constitute them at any given moment and independent of any particular groupings of these components over time. We then discuss important features of the polarities of life: Metabolism; organic structure; enclosure by a semi-permeable membrane; distinction between "self" and "other"; autonomy; neediness; teleology; sensitivity; values. Moral needs and values already arise at the most basic levels of life, even if only human

  20. Local Geostatistical Models and Big Data in Hydrological and Ecological Applications

    NASA Astrophysics Data System (ADS)

    Hristopulos, Dionissios

    2015-04-01

    helps to overcome a significant computational bottleneck of geostatistical models due to the poor scaling of the matrix inversion [4,5]. We present applications to real and simulated data sets, including the Walker lake data, and we investigate the SLI performance using various statistical cross validation measures. References [1] T. Hofmann, B. Schlkopf, A.J. Smola, Annals of Statistics, 36, 1171-1220 (2008). [2] D. T. Hristopulos, SIAM Journal on Scientific Computing, 24(6): 2125-2162 (2003). [3] D. T. Hristopulos and S. N. Elogne, IEEE Transactions on Signal Processing, 57(9): 3475-3487 (2009) [4] G. Jona Lasinio, G. Mastrantonio, and A. Pollice, Statistical Methods and Applications, 22(1):97-112 (2013) [5] Sun, Y., B. Li, and M. G. Genton (2012). Geostatistics for large datasets. In: Advances and Challenges in Space-time Modelling of Natural Events, Lecture Notes in Statistics, pp. 55-77. Springer, Berlin-Heidelberg.

  1. Collective excitations in a superfluid of color-flavor locked quark matter

    NASA Astrophysics Data System (ADS)

    Fukushima, Kenji; Iida, Kei

    2005-04-01

    We investigate collective excitations coupled with baryon density in a system of massless three-flavor quarks in the collisionless regime. By using the Nambu Jona-Lasinio (NJL) model in the mean-field approximation, we field-theoretically derive the spectra both for the normal and color-flavor locked (CFL) superfluid phases at zero temperature. In the normal phase, we obtain usual zero sound as a low-lying collective mode in the particle-hole (vector) channel. In the CFL phase, the nature of collective excitations varies in a way dependent on whether the excitation energy, ω, is larger or smaller than the threshold given by twice the pairing gap Δ, at which pair excitations with nonzero total momentum become allowed to break up into two quasiparticles. For ω≪2Δ, a phonon corresponding to fluctuations in the U(1) phase of Δ appears as a sharp peak in the particle-particle (“H”) channel. We reproduce the property known from low-energy effective theories that this mode propagates at a velocity of vH=1/√(3) in the low momentum regime; the decay constant fH obtained in the NJL model is identical with the QCD result obtained in the mean-field approximation. We also find that, as the momentum of the phonon increases, the excitation energy goes up and asymptotically approaches ω=2Δ. Above the threshold for pair excitations (ω>2Δ), zero sound manifests itself in the vector channel. By locating the zero sound pole of the vector propagator in the complex energy plane, we investigate the attenuation and energy dispersion relation of zero sound. In the long wavelength limit, the phonon mode, the only low-lying excitation, has its spectral weight in the H channel alone, while the spectral function vanishes in the vector channel. This is due to nontrivial mixing between the H and vector channels in the superfluid medium. We finally extend our study to the case of nonzero temperature. We demonstrate how Landau damping smears the phonon peak in the finite

  2. The gamma-ray pulsar PSR1706-44 and its associated SNR

    NASA Astrophysics Data System (ADS)

    McAdam, Bruce

    1994-04-01

    The Molonglo Observatory Synthesis Telescope discovered a faint supernova remnant associated with PSR 1706-44, one of only four gamma-ray pulsars. (Vela, the Crab and PSR 1509-58 also have an associated SNR.) The gamma-ray source was first discovered as 2CG342-02, the tenth strongest of 25 COS-B gamma-ray sources cataloged (Swanenburg et al., 1981, Astrophys. J. Lett. 243, L69). Low-resolution surveys show an extended (approximately 40 min x 25 min) source in the region with flux of approximately 25 Jy, suggesting a plerionic SNR (e.g. Jonas, de Jager and Baart, 1985, Astron. Astrophys. Suppl., 62, 105). A search for the gamma-ray source at 843 MHz with a resolution of 44 arcsec revealed a shell-type SNR--a half-ellipse with axes approximately 44 min x 32 min and low brightness of approximately 9 mJy per beam, giving Sigma843 = 3 x 10-21W m-2 Hz/sr (McAdam, Osborne and Parkinson, 1993, Nature, 361, 516). The Sigma-D relation suggests a diameter D approximately 34 pc at a distance of approximately 3 kpc in the Norma spiral arm of the Galaxy. It has a young (Sedov expansion) age of approximately 6000 years. The key linking the SNR and the gamma-ray source came (Kniffen et al., 1992, IAU Circ. 5485) when the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory satellite detected pulsed gamma-radiation (Thompson et al., 1992, Nature, 359, 615) from the newly-discovered PSR 1706-44 (Johnston et al., 1992, Mon. Not. R. Astron. Soc. 255, 401). The pulsar position (epoch 1950) at RA = 17 hour 06 min 05.1 sec, delta = -44 deg 25 min 15.0 sec coincides in the MOST image with a 21 mJy source on the SE and of the SNR shell. The pulsar has a period of 102 ms and slows with characteristic age 17300 years. For it to move 18 min from centre to rim of the SNR shell in this time implies a proper motion of 0.06 sec/yr which is sufficiently large to check with VLBI astrometry. At the pusar dispersion distance (1.8 kpc), or the SNR distance of 3 kpc

  3. Communicating climate change: alerting versus stimulating action, a few "philosophical" interrogations from a marine biogeochemist

    NASA Astrophysics Data System (ADS)

    Ragueneau, O.

    2009-04-01

    can come to calculate their own emissions and then, replace them in a more global context. During the debates then, very rapidly, politics and ethics come into play. Beyond the question raised above concerning outreach versus engagement, I find it VERY DIFFICULT to find the right balance between alerting and stimulating action. On one hand, we need to alert on the reality of the numbers given (and it is hard to reduce our personal emissions by a factor of 4 in France or 10 in the US), the ethical problems they raise (we, in developed countries, are responsible for the majority of past CO2 emissions and we should do the major effort, Ragueneau et al., 2008). And on the other hand, we need to remain optimistic and show that solutions do exist, if we do not want to discourage people to act. There is debate between the ethics of fear (H. Jonas) and the ethics of hope (E. Morin) as best ways to stimulate action and I feel we need to share our experiences on how best navigate between these two lines. So I would be very happy to participate in such a session to discuss the role of scientists in essential issues such as societal debates related to climate change, the frontier between outreach and political engagement, and the attitude needed to convince that there is a problem, that this problem is big and we need to stress it, but that it can be addressed with very positive implications for each of us.

  4. Strong Coupling Gauge Theories in LHC ERA

    NASA Astrophysics Data System (ADS)

    Fukaya, H.; Harada, M.; Tanabashi, M.; Yamawaki, K.

    2011-01-01

    Higgs, or techni-dilaton - composite Higgs near conformality / Koichi Yamawaki -- Phase diagram of strongly interacting theories / Francesco Sannino -- Resizing conformal windows / O. Antipin and K. Tuominen -- Nearly conformal gauge theories on the lattice / Zoltan Fodor ... [et al.] -- Going beyond QCD in lattice gauge theory / G. T. Fleming -- Phases of QCD from small to large N[symbol]: (some) lattice results / A. Deuzeman, E. Pallante and M. P. Lombardo -- Lattice gauge theory and (quasi)-conformal technicolor / D. K. Sinclair and J. B. Kogut -- Study of the running coupling constant in 10-flavor QCD with the Schrodinger functional method / N. Yamada ... [et al.] -- Study of the running coupling in twisted Polyakov scheme / T. Aoyama ... [et al.].Running coupling in strong gauge theories via the lattice / Zoltan Fodor ... [et al.] -- Higgsinoless supersymmetry and hidden gravity / Michael L. Graesser, Ryuichiro Kitano and Masafumi Kurachi -- The latest status of LHC and the EWSB physics / S. Asai -- Continuum superpartners from supersymmetric unparticles / Hsin-Chia Cheng -- Review of minimal flavor constraints for technicolor / Hidenori S. Fukano and Francesco Sannino -- Standard model and high energy Lorentz violation / Damiano Anselmi -- Dynamical electroweak symmetry breaking and fourth family / Michio Hashimoto -- Holmorphic supersymmetric Nambu-Jona-Lasino model and dynamical electroweak symmetry breaking / Dong-Won Jung, Otto C. W. Kong and Jae Sik Lee -- Ratchet model of Baryogenesis / Tatsu Takeuchi, Azusa Minamizaki and Akio Sugamoto -- Classical solutions of field equations in Einstein Gauss-Bonnet gravity / P. Suranyi, C. Vaz and L. C. R. Wijewardhana -- Black holes constitute all dark matter / Paul H. Frampton -- Electroweak precision test and Z [symbol] in the three site Higgsless model / Tomohiro Abe -- Chiral symmetry and BRST symmetry breaking, quaternion reality and the lattice simulation / Sadataka Furui -- Holographic techni-dilaton, or

  5. Reconstruction of 3d grain boundaries from rock thin sections, using polarised light

    NASA Astrophysics Data System (ADS)

    Markus Hammes, Daniel; Peternell, Mark

    2016-04-01

    Grain boundaries affect the physical and chemical properties of polycrystalline materials significantly by initiating reactions and collecting impurities (Birchenall, 1959), and play an essential role in recrystallization (Doherty et al. 1997). In particular, the shape and crystallographic orientation of grain boundaries reveal the deformation and annealing history of rocks (Kruhl and Peternell 2002, Kuntcheva et al. 2006). However, there is a lack of non-destructive and easy-to-use computer supported methods to determine grain boundary geometries in 3D. The only available instrument using optical light to measure grain boundary angles is still the polarising microscope with attached universal stage; operated manually and time-consuming in use. Here we present a new approach to determine 3d grain boundary orientations from 2D rock thin sections. The data is recorded by using an automatic fabric analyser microscope (Peternell et al., 2010). Due to its unique arrangement of 9 light directions the highest birefringence colour due to each light direction and crystal orientation (retardation) can be determined at each pixel in the field of view. Retardation profiles across grain boundaries enable the calculation of grain boundary angle and direction. The data for all positions separating the grains are combined and further processed. In combination with the lateral position of the grain boundary, acquired using the FAME software (Hammes and Peternell, in review), the data is used to reconstruct a 3d grain boundary model. The processing of data is almost fully automatic by using MATLAB®. Only minor manual input is required. The applicability was demonstrated on quartzite samples, but the method is not solely restricted on quartz grains and other birefringent polycrystalline materials could be used instead. References: Birchenall, C.E., 1959: Physical Metallurgy. McGraw-Hill, New York. Doherty, R.D., Hughes, D.A., Humphreys, F.J., Jonas, J.J., Juul Jensen, D., Kassner, M

  6. EDITORIAL: Focus on Nanostructured Soft Matter

    NASA Astrophysics Data System (ADS)

    Reineker, Peter; Schülz, Michael

    2004-01-01

    Nanostructures in general are playing a more and more important role in the physics and chemistry of condensed matter systems including both hard and soft materials. This Focus Issue concentrates particularly on recent developments in Nanostructured Soft Matter Systems. Many interesting questions related to both fundamental and applied research in this field have arisen. Some of them are connected to the chemical reactions that take place during the irreversible formation of soft matter systems. Others refer to the theoretical and experimental investigations of structures and topologies of `nanostructured soft matter', e.g. heterogeneous polymers and polymer networks, or soft matter at low dimensions or in constrained geometries. Additional research has also been devoted to the dynamics of other complex nanostructured systems, such as the structure formation on the basis of polymer systems and polyelectrolytes, and several kinds of phase transitions on nano- and microscales. The contributions collected here present the most up-to-date research results on all of these topics. New Journal of Physics, as an electronic journal, is perfectly suited for the presentation of the complex results that the experimental and theoretical investigations reported here yield. The articles that will follow provide a number of excellent examples of the use of animations, movies and colour features for the added benefit of the reader. Focus on Nanostructured Soft Matter Contents Phase separation kinetics in compressible polymer solutions: computer simulation of the early stages Peter Virnau, Marcus Müller, Luis González MacDowell and Kurt Binder Spectral dynamics in the B800 band of LH2 from Rhodospirillum molischianum: a single-molecule study Clemens Hofmann, Thijs J Aartsma, Hartmut Michel and Jürgen Köhler Adsorption of polyacrylic acid on self-assembled monolayers investigated by single-molecule force spectroscopy Claudia Friedsam, Aránzazu Del Campo Bécares, Ulrich Jonas

  7. 2012 best practices for repositories collection, storage, retrieval, and distribution of biological materials for research international society for biological and environmental repositories.

    PubMed

    2012-04-01

    Third Edition [Formula: see text] [Box: see text] Printed with permission from the International Society for Biological and Environmental Repositories (ISBER) © 2011 ISBER All Rights Reserved Editor-in-Chief Lori D. Campbell, PhD Associate Editors Fay Betsou, PhD Debra Leiolani Garcia, MPA Judith G. Giri, PhD Karen E. Pitt, PhD Rebecca S. Pugh, MS Katherine C. Sexton, MBA Amy P.N. Skubitz, PhD Stella B. Somiari, PhD Individual Contributors to the Third Edition Jonas Astrin, Susan Baker, Thomas J. Barr, Erica Benson, Mark Cada, Lori Campbell, Antonio Hugo Jose Froes Marques Campos, David Carpentieri, Omoshile Clement, Domenico Coppola, Yvonne De Souza, Paul Fearn, Kelly Feil, Debra Garcia, Judith Giri, William E. Grizzle, Kathleen Groover, Keith Harding, Edward Kaercher, Joseph Kessler, Sarah Loud, Hannah Maynor, Kevin McCluskey, Kevin Meagher, Cheryl Michels, Lisa Miranda, Judy Muller-Cohn, Rolf Muller, James O'Sullivan, Karen Pitt, Rebecca Pugh, Rivka Ravid, Katherine Sexton, Ricardo Luis A. Silva, Frank Simione, Amy Skubitz, Stella Somiari, Frans van der Horst, Gavin Welch, Andy Zaayenga 2012 Best Practices for Repositories: Collection, Storage, Retrieval and Distribution of Biological Materials for Research INTERNATIONAL SOCIETY FOR BIOLOGICAL AND ENVIRONMENTAL REPOSITORIES (ISBER) INTRODUCTION T he availability of high quality biological and environmental specimens for research purposes requires the development of standardized methods for collection, long-term storage, retrieval and distribution of specimens that will enable their future use. Sharing successful strategies for accomplishing this goal is one of the driving forces for the International Society for Biological and Environmental Repositories (ISBER). For more information about ISBER see www.isber.org . ISBER's Best Practices for Repositories (Best Practices) reflect the collective experience of its members and has received broad input from other repository professionals. Throughout this document

  8. Annotated type catalogue of the Bulimulidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S.H.; Ablett, Jonathan D.

    2014-01-01

    , 1909; Bulimus (Otostomus) napo Angas, 1878; Drymaeus notabilis da Costa, 1906; Drymaeus notatus da Costa, 1906; Bulimulus (Drymaeus) nubilus Preston, 1903; Drymaeus obliquistriatus da Costa, 1901; Bulimus (Drymaeus) ochrocheilus E.A. Smith, 1877; Bulimus (Drymaeus) orthostoma E.A. Smith, 1877; Drymaeus expansus perenensis da Costa, 1901; Bulimulus pergracilis Rolle, 1904; Bulimulus (Drymaeus) plicatoliratus da Costa, 1898; Drymaeus prestoni da Costa, 1906; Drymaeus punctatus da Costa, 1907; Bulimus (Leptomerus) sanctaeluciae E.A. Smith, 1889; Bulimulus (Drymaeus) selli Preston, 1909; Drymaeus subventricosus da Costa, 1901; Bulimulus (Drymaeus) tigrinus da Costa, 1898; Drymaeus volsus Fulton, 1907; Drymaeus wintlei Finch, 1929; Bulimus zhorquinensis Angas, 1879; Bulimulus (Drymaeus) ziczac da Costa, 1898. The following junior subjective synonyms are established: Bulimus antioquensis Pfeiffer, 1855 = Bulimus baranguillanus Pfeiffer, 1853; Drymaeus bellus da Costa, 1906 = Drymaeus blandi Pilsbry, 1897; Bulimus hachensis Reeve 1850 = Bulimus gruneri Pfeiffer, 1846 = Bulimus columbianus Lea, 1838; Bulimus (Otostomus) lamas Higgins 1868 = Bulimus trujillensis Philippi, 1867; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895 = Bulimulus (Drymaeus) binominis E.A. Smith, 1895; Drymaeus multispira da Costa, 1904 = Helix torallyi d’Orbigny, 1835; Bulimulus (Drymaeus) plicatoliratus Da Costa, 1898 = Bulimus convexus Pfeiffer, 1855; Bulimus sugillatus Pfeiffer, 1857 = Bulimus rivasii d’Orbigny, 1837; Bulimus meridionalis Reeve 1848 [June] = Bulimus voithianus Pfeiffer, 1847. New combinations are: Bostryx montagnei (d’Orbigny, 1837); Bostryx obliquiportus (da Costa, 1901); Bulimulus heloicus (d’Orbigny, 1835); Drymaeus (Drymaeus) lusorius (Pfeiffer, 1855); Drymaeus (Drymaeus) trigonostomus (Jonas, 1844); Drymaeus (Drymaeus) wintlei Finch, 1929; Drymaeus (Mesembrinus) conicus da Costa, 1907; Kuschelenia (Kuschelenia) culminea culminea (d’Orbigny, 1835); Kusche

  9. Pollen-inferred quantitative reconstructions of Holocene land-cover in NW Europe for the evaluation of past climate-vegetation feedbacks - The Swedish LANDCLIM project and the NordForsk LANDCLIM network

    NASA Astrophysics Data System (ADS)

    Gaillard, Marie-Jose; Sugita, Shinya; Rundgren, Mats; Smith, Benjamin; Mazier, Florence; Trondman, Anna-Kari; Fyfe, Ralph; Kokfelt, Ulla; Nielsen, Anne-Birgitte; Strandberg, Gustav

    2010-05-01

    Biology, University of Bergen); Pim van der Knaap (Institute of Plant Sciences, University of Bern); Malgorzata Latalowa (University of Gdansk); Michelle Leydet (IMEP CNRS 6116, University of Marseille III); Teija Alenius (Finnish Geological Survey, Espoo), Heather Almquist-Jacobson (Univ. Montana, USA), Jonas Bergman (Univ. Stockholm), Rixt de Jong (Univ. Bern), Jutta Lechterbeck (Hemmenhofen, Germany), Ann-Marie Robertsson (Univ. Stockholm), Ulf Segerström and Henrik von Stedingk (Univ. Umeå), Heikki Seppä (Univ. Helsinki). Sugita 2007. The Holocene, 17, 229-241.

  10. EDITORIAL: Focus on Quantum Correlations in Tailored Matter

    NASA Astrophysics Data System (ADS)

    Muramatsu, Alejandro; Pfau, Tilman

    2008-04-01

    molecules L Wang, A Rastelli, S Kiravittaya, P Atkinson, F Ding, C C Bof Bufon, C Hermannstädter, M Witzany, G J Beirne, P Michler and O G Schmidt Effective parameters for weakly coupled Bose-Einstein condensates S Giovanazzi, J Esteve and M K Oberthaler Current statistics of correlated charge tunnelling through an impurity in a 1D wire Alexander Herzog and Ulrich Weiss Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap Stephan A Schulz, Ulrich Poschinger, Frank Ziesel and Ferdinand Schmidt-Kaler The trapped two-dimensional Bose gas: from Bose-Einstein condensation to Berezinskii-Kosterlitz-Thouless physics Z Hadzibabic, P Krüger, M Cheneau, S P Rath and J Dalibard Dynamical protection of quantum computation from decoherence in laser-driven cold-ion and cold-atom systems Goren Gordon and Gershon Kurizki Spin-flip and spin-conserving optical transitions of the nitrogen-vacancy centre in diamond Ph Tamarat, N B Manson, J P Harrison, R L McMurtrie, A Nizovtsev, C Santori, R G Beausoleil, P Neumann, T Gaebel, F Jelezko, P Hemmer and J Wrachtrup Superconductivity in the attractive Hubbard model: functional renormalization group analysis R Gersch, C Honerkamp and W Metzner Quantum stability of Mott-insulator states of ultracold atoms in optical resonators Jonas Larson, Sonia Fernández-Vidal, Giovanna Morigi and Maciej Lewenstein

  11. Exotic States of Nuclear Matter

    NASA Astrophysics Data System (ADS)

    Lombardo, Umberto; Baldo, Marcello; Burgio, Fiorella; Schulze, Hans-Josef

    2008-02-01

    . Pairing in BCS theory and beyond / L. G. Cao, U. Lombardo & P. Schuck. Pinning and binding energies for vortices in neutron stars: comments on recent results / P. M. Pizzochero. Structure of a vortex in the inner crust of neutron stars / P. Avogadro ... [et al.]. The dynamics of vortex pinning in the neutron star crust / B. Link -- pt. H. Poster session. Microscopic data and supernovae evolution / P. Blottiau, Ph. Mellor & J. Margueron. Parity doublet model applied to neutron star / V. Dexheimer, S. Schramm & H. Stoecker. Structure of hybrid stars / D. Jaccarino, U. Lombardo & G. X. Peng. Nuclear three-body force from the Nijmegen potential / Z. H. Li ... [et al.]. Monopole excitations in QRPA on top of HFB / J. Li, G. Colò & J. Meng. The influence of the [symbol]-field on neutron stars / A. J. Mi, W. Zuo & A. Li. Magnetization of color-flavor locked matter / J. Noronha & I. A. Shovkovy. Ab initio pairing gap calculation for a slab of nuclear matter with Paris and Argonne V18 bare NN-potentials / S. S. Pankratov et al. Hybrid neutron stars within the Nambu-Jona-Lasinio model and confinement / S. Plumari et al. A study of pairing interaction in a separable form / Y. Tian, Z. Ma & P. Ring. Isospin dependence of nuclear matter / E. N. E Van Dalen ... [et al.]. Ejected elements from the envelope of compact stars by QCD phase transition / N. Yasutake et al. Microscopic three-body force effect on nucleon-nucleon cross sections / H. F. Zhang et al. Tensor correlations and single-particle states in medium-mass nuclei / W. Zou et al.

  12. FOREWORD: The 70th birthday of Professor Stig Stenholm The 70th birthday of Professor Stig Stenholm

    NASA Astrophysics Data System (ADS)

    Suominen, Kalle-Antti

    2010-09-01

    information [7] and in Stockholm he had, again, very successful postdocs such as Ulf Leonhardt. Finally, in 2005, Stig Stenholm retired, although he is still active, writing papers, taking part in conferences and making research visits. We honoured his 70th birthday at the CEWQO2009 conference, and hope that the future provides us with further opportunities for such events. Looking at the obituary of Dirk ter Haar, I see that his style with students reminds me of Stig's approach. In my opinion, Stig expects independence and initiative from a student, giving perhaps a broad topic in which the student is expected to find his or her own way, whilst working perhaps with a postdoc. Juha Javanainen has talked about the 'sink or swim' style (not referring to Stig, though). There is a famous series of children's books about Moomin trolls by Tove Jansson (another Swedish-speaking Finn like Stig). In one of them, the Moomin find in early spring a small flower in a patch of land uncovered by snow, pushing its way up. One of them wants to cover it against frost during the night, but another says 'Don't, it'll fare better later if it has some difficulties at first'. At CEWQO2009 Stig gave the full list of his finished PhD students: Rainer Salomaa (1973), Temba Dlodlo (1980), Juha Javanainen (1980), Markus Lindberg (1985), Matti Kaivola (1985), Birger Ståhlberg (1985), Kalle-Antti Suominen (1992), Mackillo Kira (1995), Päivi Törmä (1996), Asta Paloviita (1997), Patrik Öhberg (1998), Martti Havukainen (1999), Erika Andersson (2000), Pawel Piwnicki (2001), Åsa Larson (2001), Markku Jääskeläinen (2003), and Jonas Larson (2005). One should also mention Erkki Kyrölä, who eventually graduated at Rochester and Olli Serimaa, who never graduated but published some important early-stage laser cooling work. As a final note I must mention a passion that Stig and I share, namely books. I have nearly 400 professional physics and mathematics books, but I am certain that the size of Stig

  13. EDITORIAL: Van der Waals interactions in advanced materials, in memory of David C Langreth Van der Waals interactions in advanced materials, in memory of David C Langreth

    NASA Astrophysics Data System (ADS)

    Hyldgaard, Per; Rahman, Talat S.

    2012-10-01

    Rahman Frictional temperature rise in a sliding physisorbed monolayer of Kr/grapheneM Walker, C Jaye, J Krim and Milton W Cole How to modify the van der Waals and Casimir forces without change of the dielectric permittivityG L Klimchitskaya, U Mohideen and V M Mostepanenko Spectroscopic characterization of van der Waals interactions in a metal organic framework with unsaturated metal centers: MOF-74-MgNour Nijem, Pieremanuele Canepa, Lingzhu Kong, Haohan Wu, Jing Li, Timo Thonhauser and Yves J Chabal A theoretical study of the hydrogen-storage potential of (H2)4CH4 in metal organic framework materials and carbon nanotubesQ Li and T Thonhauser The influence of dispersion interactions on the hydrogen adsorption properties of expanded graphiteYungok Ihm, Valentino R Cooper, Lujian Peng and James R Morris A DFT-D study of structural and energetic properties of TiO2 modificationsJonas Moellmann, Stephan Ehrlich, Ralf Tonner and Stefan Grimme Spherical-shell model for the van der Waals coefficients between fullerenes and/or nearly spherical nanoclustersJohn P Perdew, Jianmin Tao, Pan Hao, Adrienn Ruzsinszky, Gábor I Csonka and J M Pitarke Dynamical screening of the van der Waals interaction between graphene layersY J Dappe, P G Bolcatto, J Ortega and F Flores Structural evolution of amino acid crystals under stress from a non-empirical density functionalRiccardo Sabatini, Emine Küçükbenli, Brian Kolb, T Thonhauser and Stefano de Gironcoli Physisorption of nucleobases on graphene: a comparative van der Waals studyDuy Le, Abdelkader Kara, Elsebeth Schröder, Per Hyldgaard and Talat S Rahman The role of van der Waals interactions in the adsorption of noble gases on metal surfacesDe-Li Chen, W A Al-Saidi and J Karl Johnson Desorption of n-alkanes from graphene: a van der Waals density functional studyElisa Londero, Emma K Karlson, Marcus Landahl, Dimitri Ostrovskii, Jonatan D Rydberg and Elsebeth Schröder Benchmarking van der Waals density functionals with experimental data