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Sample records for airy stress function

  1. The structure of Airy's stress function in multiply connected regions

    NASA Technical Reports Server (NTRS)

    Grioli, Giusippe

    1951-01-01

    In solving two-dimensional problems using Airy's stress function for multiply connected regions, the form of the function depends on the dislocations and boundary forces present. The structure of Airy's function is shown to consist of a part expressible in terms of boundary forces and a part expressible in the manner of Poincare. Meanings of the constants occurring in Poincare's expression are discussed.

  2. Acoustic Resonance of a Two-Dimensional Isotropic Medium Studied Using Airy Stress Function

    NASA Astrophysics Data System (ADS)

    Tarumi, Ryuichi; Yamada, Shinpei; Shibutani, Yoji

    2012-07-01

    We have developed a theory that determines a complete set of stress field, σij, in a freely vibrating two-dimensional isotropic medium within the framework of the calculus of variation. Our formulation is based on the Airy stress function φ and the minimization of the complementary strain energy under the constrain condition || φ|| 2L2 =const. By the Ritz method, the constrained variational problem becomes a linear eigenvalue problem. Numerical analysis yields 36 types of the stress functions φi. Unlike the stress fields determined from the conventional resonant ultrasound spectroscopy theory, the stress fields derived from the stress functions φi explicitly satisfy the stress-free natural boundary condition and the equilibrium equation. It is also confirmed that the 36 resonant modes can be classified into four groups according to the parity of the coefficient of the basis function. Furthermore, the stress functions φi are orthogonal in the sense of the L2 inner product. These features are similar to those of the conventional resonant ultrasound spectroscopy (RUS) theory.

  3. Generalized Airy functions for use in one-dimensional quantum mechanical problems

    NASA Technical Reports Server (NTRS)

    Eaves, J. O.

    1972-01-01

    The solution of the one dimensional, time independent, Schroedinger equation in which the energy minus the potential varies as the nth power of the distance is obtained from proper linear combinations of Bessel functions. The linear combinations called generalized Airy functions, reduce to the usual Airy functions Ai(x) and Bi(x) when n equals 1 and have the same type of simple asymptotic behavior. Expressions for the generalized Airy functions which can be evaluated by the method of generalized Gaussian quadrature are obtained.

  4. Numerical evaluation of the incomplete airy functions and their application to high frequency scattering and diffraction

    NASA Technical Reports Server (NTRS)

    Constantinides, E. D.; Marhefka, R. J.

    1992-01-01

    The incomplete Airy integrals serve as canonical functions for the uniform ray optical solutions to several high frequency scattering and diffraction problems that involve a class of integrals characterized by two stationary points that are arbitrarily close to one another or to an integration endpoint. Integrals of such analytical properties describe transition region phenomena associated with composite shadow boundaries. An efficient and accurate method for computing the incomplete Airy functions would make the solutions to such problems useful for engineering purposes. Here, a convergent series solution form for the incomplete Airy functions is derived. Asymptotic expansions involving several terms were also developed and serve as large argument approximations. The combination of the series solution form with the asymptotic formulae provides for an efficient and accurate computation of the incomplete Airy functions. Validation of accuracy is accomplished using direct numerical integration data.

  5. Inpainting using airy diffusion

    NASA Astrophysics Data System (ADS)

    Lorduy Hernandez, Sara

    2015-09-01

    One inpainting procedure based on Airy diffusion is proposed, implemented via Maple and applied to some digital images. Airy diffusion is a partial differential equation with spatial derivatives of third order in contrast with the usual diffusion with spatial derivatives of second order. Airy diffusion generates the Airy semigroup in terms of the Airy functions which can be rewritten in terms of Bessel functions. The Airy diffusion can be used to smooth an image with the corresponding noise elimination via convolution. Also the Airy diffusion can be used to erase objects from an image. We build an algorithm using the Maple package ImageTools and such algorithm is tested using some images. Our results using Airy diffusion are compared with the similar results using standard diffusion. We observe that Airy diffusion generates powerful filters for image processing which could be incorporated in the usual packages for image processing such as ImageJ and Photoshop. Also is interesting to consider the possibility to incorporate the Airy filters as applications for smartphones and smart-glasses.

  6. Airy Equation for the Topological String Partition Function in a Scaling Limit

    NASA Astrophysics Data System (ADS)

    Alim, Murad; Yau, Shing-Tung; Zhou, Jie

    2016-04-01

    We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.

  7. Airy Equation for the Topological String Partition Function in a Scaling Limit

    NASA Astrophysics Data System (ADS)

    Alim, Murad; Yau, Shing-Tung; Zhou, Jie

    2016-06-01

    We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.

  8. Diffraction by three-dimensional slit-shape curves: decomposition in terms of Airy and Pearcey functions.

    PubMed

    Martinez-Vara, P; Barranco, J Silva; De Los Santos G, S I; Munoz-Lopez, J; Torres-Rodriguez, M A; Xique, R Suarez; Martinez-Niconoff, G

    2015-08-01

    We analyze the diffraction field generated by coherent illumination of a three-dimensional transmittance characterized by a slit-shape curve. Generic features are obtained using the Frenet-Serret equations, which allow a decomposition of the optical field. The analysis is performed by describing the influence of the curvature and torsion on osculating, normal, and rectifying planes. We show that the diffracted field has a decomposition in three optical fields propagating along three optical axes that are mutually perpendicular. The decomposition is in terms of the Pearcey and Airy functions, and the generalized Airy function. Experimental results are shown. PMID:26258341

  9. Airy function approach and Numerov method to study the anharmonic oscillator potentials V(x) = Ax2α + Bx2

    NASA Astrophysics Data System (ADS)

    Al Sdran, N.; Maiz, F.

    2016-06-01

    The numerical solutions of the time independent Schrödinger equation of different one-dimensional potentials forms are sometime achieved by the asymptotic iteration method. Its importance appears, for example, on its efficiency to describe vibrational system in quantum mechanics. In this paper, the Airy function approach and the Numerov method have been used and presented to study the oscillator anharmonic potential V(x) = Ax2α + Bx2, (A>0, B<0), with (α = 2) for quadratic, (α =3) for sextic and (α =4) for octic anharmonic oscillators. The Airy function approach is based on the replacement of the real potential V(x) by a piecewise-linear potential v(x), while, the Numerov method is based on the discretization of the wave function on the x-axis. The first energies levels have been calculated and the wave functions for the sextic system have been evaluated. These specific values are unlimited by the magnitude of A, B and α. It's found that the obtained results are in good agreement with the previous results obtained by the asymptotic iteration method for α =3.

  10. Intensity-symmetric Airy beams.

    PubMed

    Vaveliuk, P; Lencina, Alberto; Rodrigo, Jose A; Martnez-Matos, Ó

    2015-03-01

    Theoretical, numerical, and experimental research on a novel family of Airy beams in rectangular coordinates having a symmetric transverse pattern of light intensity is presented. The intensity-symmetric Airy beams include both the symmetric Airy beam whose field amplitude is an even function of the transverse coordinates and the antisymmetric Airy beam whose field amplitude is an odd function of such coordinates. The theoretical foundations are based on the relationship of the symmetries of the spectral phase with the cosine and sine Fourier transforms. These beams are analyzed in a propagation range also including the region preceding the Fourier plane. These beams exhibit autofocusing, collapse, self-bending, and reversal propagation. Moreover, the intensity distribution is strongly asymmetric with respect to the Fourier plane. All these peculiar features were not reported for other classes of paraxial beams in a rectangular frame. The experimental generation of intensity-symmetric Airy beams is demonstrated supporting the theoretical predictions. Possible applications in planar waveguide writing and optical trapping are also discussed. PMID:26366655

  11. Acoustic non-diffracting Airy beam

    SciTech Connect

    Lin, Zhou; Guo, Xiasheng Tu, Juan; Ma, Qingyu; Wu, Junru; Zhang, Dong

    2015-03-14

    The acoustic non-diffracting Airy beam as its optical counterpart has unique features of self-bending and self-healing. The complexity of most current designs handicaps its applications. A simple design of an acoustic source capable of generating multi-frequency and broad-band acoustic Airy beam has been theoretically demonstrated by numerical simulations. In the design, a piston transducer is corrugated to induce spatial phase variation for transducing the Airy function. The piston's surface is grooved in a pattern that the width of each groove corresponds to the half wavelength of Airy function. The resulted frequency characteristics and its dependence on the size of the piston source are also discussed. This simple design may promote the wide applications of acoustic Airy beam particularly in the field of medical ultrasound.

  12. Double scaling limits and airy functions for {ital O}({ital N}) vector sigma models with elementary catastrophes or the catastrophe {ital X}{sub 9}

    SciTech Connect

    Ruehl, W.

    1996-05-01

    One and two vector sigma models are defined that possess catastrophes in their action. Each catastrophe defines a double scaling limit at {ital N}{r_arrow}{infinity}. Critical indices are calculated and the Airy functions are shown to satisfy RG equations. Copyright {copyright} 1996 Academic Press, Inc.

  13. Generation of electron Airy beams.

    PubMed

    Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-02-21

    Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories. PMID:23426323

  14. Stationary nonlinear Airy beams

    SciTech Connect

    Lotti, A.; Faccio, D.; Couairon, A.; Papazoglou, D. G.; Panagiotopoulos, P.; Tzortzakis, S.; Abdollahpour, D.

    2011-08-15

    We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.

  15. Creating Airy beams employing a transmissive spatial light modulator.

    PubMed

    Latychevskaia, Tatiana; Schachtler, Daniel; Fink, Hans-Werner

    2016-08-01

    We present a detailed study of two novel methods for shaping the light optical wavefront by employing a transmissive spatial light modulator (SLM). Conventionally, optical Airy beams are created by employing SLMs in the so-called all-phase mode. In the first method, a numerically simulated lens phase distribution is loaded directly onto the SLM, together with the cubic phase distribution. An Airy beam is generated at the focal plane of the numerical lens. We provide for the first time, to the best of our knowledge, quantitative properties of the formed Airy beam. We derive the formula for deflection of the intensity maximum of the so-formed Airy beam, which is different from the quadratic deflection typical of Airy beams. We cross-validate the derived formula by both simulations and experiment. The second method is based on the fact that a system consisting of a transmissive SLM sandwiched between two polarizers can create a transmission function with negative values. This observation alone has the potential for various other wavefront modulations where the transmission function requires negative values. As an example for this method, we demonstrate that a wavefront can be modulated by passing the SLM system with transmission function with negative values by loading an Airy function distribution directly onto the SLM. Since the Airy function is a real-valued function but also with negative values, an Airy beam can be generated by direct transfer of the Airy function distribution onto such an SLM system. In this way, an Airy beam is generated immediately behind the SLM. As both new methods do not employ a physical lens, the two setups are more compact than conventional setups for creating Airy beams. We compare the performance of the two novel methods and the properties of the created Airy beams. PMID:27505393

  16. Model of a tunneling current in a p-n junction based on armchair graphene nanoribbons - an Airy function approach and a transfer matrix method

    SciTech Connect

    Suhendi, Endi; Syariati, Rifki; Noor, Fatimah A.; Khairurrijal; Kurniasih, Neny

    2014-03-24

    We modeled a tunneling current in a p-n junction based on armchair graphene nanoribbons (AGNRs) by using an Airy function approach (AFA) and a transfer matrix method (TMM). We used β-type AGNRs, in which its band gap energy and electron effective mass depends on its width as given by the extended Huckel theory. It was shown that the tunneling currents evaluated by employing the AFA are the same as those obtained under the TMM. Moreover, the calculated tunneling current was proportional to the voltage bias and inversely with temperature.

  17. Propagation Dynamics of Airy Water-Wave Pulses.

    PubMed

    Fu, Shenhe; Tsur, Yuval; Zhou, Jianying; Shemer, Lev; Arie, Ady

    2015-07-17

    We observe the propagation dynamics of surface gravity water waves, having an Airy function envelope, in both the linear and the nonlinear regimes. In the linear regime, the shape of the envelope is preserved while propagating in an 18-m water tank, despite the inherent dispersion of the wave packet. The Airy wave function can propagate at a velocity that is slower (or faster if the Airy envelope is inverted) than the group velocity. Furthermore, the introduction of the Airy wave packet as surface water waves enables the observation of its position-dependent chirp and cubic-phase offset, predicted more than 35 years ago, for the first time. When increasing the envelope of the input Airy pulse, nonlinear effects become dominant, and are manifested by the generation of water-wave solitons. PMID:26230797

  18. Airy structure in 16O+14C nuclear rainbow scattering

    NASA Astrophysics Data System (ADS)

    Ohkubo, S.; Hirabayashi, Y.

    2015-08-01

    The Airy structure in 16 O +14 C rainbow scattering is studied with an extended double-folding (EDF) model that describes all the diagonal and off-diagonal coupling potentials derived from the microscopic realistic wave functions for 16 O by using a density-dependent nucleon-nucleon force. The experimental angular distributions at EL=132 , 281, and 382.2 MeV are well reproduced by the calculations. By studying the energy evolution of the Airy structure, the Airy minimum around θ =76∘ in the angular distribution at EL=132 MeV is assigned as the second-order Airy minimum A 2 in contrast to the recent literature which assigns it as the third order A 3 . The Airy minima in the 90∘ excitation function is investigated in comparison with well-known 16 O +16 O and 12 C +12 C systems. Evolution of the Airy structure into the molecular resonances with the 16 O +14 C cluster structure in the low-energy region around Ec .m .=30 MeV is discussed. It is predicted theoretically for the first time for a non-4 N 16O +14 C system that Airy elephants in the 90∘ excitation function are present.

  19. Accelerating Airy beams in the presence of inhomogeneities

    NASA Astrophysics Data System (ADS)

    Besieris, Ioannis M.; Shaarawi, Amr M.; Zamboni-Rached, Michel

    2016-06-01

    Studies have already been made of accelerating Airy beams in the presence of deterministic inhomogeneities, illustrating, in particular, that the inherent self-healing properties of such beams are preserved. The cases of a range-dependent linear transverse potential and a converging GRIN structure (harmonic oscillator) have been examined thoroughly. Examples will be given in this article of novel accelerating Airy beams in the presence of five other types of potential functions. Three of the resulting exact analytical solutions have a common salient characteristic property: they are constructed using the free-space accelerating Airy beam solution as a seed.

  20. Voigt Airy surface magneto plasmons.

    PubMed

    Hu, Bin; Wang, Qi Jie; Zhang, Ying

    2012-09-10

    We present a basic theory on Airy surface magneto plasmons (SMPs) at the interface between a dielectric layer and a metal layer (or a doped semiconductor layer) under an external static magnetic field in the Voigt configuration. It is shown that, in the paraxial approximation, the Airy SMPs can propagate along the surface without violating the nondiffracting characteristics, while the ballistic trajectory of the Airy SMPs can be tuned by the applied magnetic field. In addition, the self-deflection-tuning property of the Airy SMPs depends on the direction of the external magnetic field applied, owing to the nonreciprocal effect. PMID:23037243

  1. Controllable Airy-like beams induced by tunable phase patterns

    NASA Astrophysics Data System (ADS)

    Li, D.; Qian, Y.

    2016-01-01

    We propose and experimentally observe a novel family of Airy-like beams. First, we theoretically investigate the physical generation of our proposed controllable Airy-like beams by introducing a rotation angle factor into the phase function, which can regulate and flexibly control the beam wavefront. Meanwhile we can also readily control the main lobes of these beams to follow appointed parabolic trajectories using the rotation angle factor. We also demonstrate that the controllable Airy-like beams lack the properties of being diffraction-free and self-healing. The experiments are performed and the results are in accord with the theoretical simulations. We believe that the intriguing characteristics of our proposed Airy-like beams could provide more degrees of freedom, and are likely to give rise to new applications and lend versatility to the emerging field.

  2. Bohmian trajectories of Airy packets

    SciTech Connect

    Nassar, Antonio B.; Miret-Artés, Salvador

    2014-09-15

    The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space–time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject’s theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.

  3. Bohmian trajectories of Airy packets

    NASA Astrophysics Data System (ADS)

    Nassar, Antonio B.; Miret-Artés, Salvador

    2014-09-01

    The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space-time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject's theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.

  4. Airy beam optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.

    2016-05-01

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond).

  5. Airy beam optical parametric oscillator.

    PubMed

    Aadhi, A; Chaitanya, N Apurv; Jabir, M V; Vaity, Pravin; Singh, R P; Samanta, G K

    2016-01-01

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51-1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond). PMID:27143582

  6. Airy beam optical parametric oscillator

    PubMed Central

    Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.

    2016-01-01

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond). PMID:27143582

  7. Accurate Thermal Stresses for Beams: Normal Stress

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; Pilkey, Walter D.

    2003-01-01

    Formulations for a general theory of thermoelasticity to generate accurate thermal stresses for structural members of aeronautical vehicles were developed in 1954 by Boley. The formulation also provides three normal stresses and a shear stress along the entire length of the beam. The Poisson effect of the lateral and transverse normal stresses on a thermally loaded beam is taken into account in this theory by employing an Airy stress function. The Airy stress function enables the reduction of the three-dimensional thermal stress problem to a two-dimensional one. Numerical results from the general theory of thermoelasticity are compared to those obtained from strength of materials. It is concluded that the theory of thermoelasticity for prismatic beams proposed in this paper can be used instead of strength of materials when precise stress results are desired.

  8. Accurate Thermal Stresses for Beams: Normal Stress

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; Pilkey, Walter D.

    2002-01-01

    Formulations for a general theory of thermoelasticity to generate accurate thermal stresses for structural members of aeronautical vehicles were developed in 1954 by Boley. The formulation also provides three normal stresses and a shear stress along the entire length of the beam. The Poisson effect of the lateral and transverse normal stresses on a thermally loaded beam is taken into account in this theory by employing an Airy stress function. The Airy stress function enables the reduction of the three-dimensional thermal stress problem to a two-dimensional one. Numerical results from the general theory of thermoelasticity are compared to those obtained from strength of materials. It is concluded that the theory of thermoelasticity for prismatic beams proposed in this paper can be used instead of strength of materials when precise stress results are desired.

  9. Solitons shedding from Airy beams and bound states of breathing Airy solitons in nonlocal nonlinear media

    PubMed Central

    Shen, Ming; Gao, Jinsong; Ge, Lijuan

    2015-01-01

    We investigate the spatially optical solitons shedding from Airy beams and anomalous interactions of Airy beams in nonlocal nonlinear media by means of direct numerical simulations. Numerical results show that nonlocality has profound effects on the propagation dynamics of the solitons shedding from the Airy beam. It is also shown that the strong nonlocality can support periodic intensity distribution of Airy beams with opposite bending directions. Nonlocality also provides a long-range attractive force between Airy beams, leading to the formation of stable bound states of both in-phase and out-of-phase breathing Airy solitons which always repel in local media. PMID:25900878

  10. Rainbows: Mie computations and the Airy approximation.

    PubMed

    Wang, R T; van de Hulst, H C

    1991-01-01

    Efficient and accurate computation of the scattered intensity pattern by the Mie formulas is now feasible for size parameters up to x = 50,000 at least, which in visual light means spherical drops with diameters up to 6 mm. We present a method for evaluating the Mie coefficients from the ratios between Riccati-Bessel and Neumann functions of successive order. We probe the applicability of the Airy approximation, which we generalize to rainbows of arbitrary p (number of internal reflections = p - 1), by comparing the Mie and Airy intensity patterns. Millimeter size water drops show a match in all details, including the position and intensity of the supernumerary maxima and the polarization. A fairly good match is still seen for drops of 0.1 mm. A small spread in sizes helps to smooth out irrelevant detail. The dark band between the rainbows is used to test more subtle features. We conclude that this band contains not only externally reflected light (p = 0) but also a sizable contribution f rom the p = 6 and p = 7 rainbows, which shift rapidly with wavelength. The higher the refractive index, the closer both theories agree on the first primary rainbow (p = 2) peak for drop diameters as small as 0.02 mm. This may be useful in supporting experimental work. PMID:20581954

  11. Multi-focus of modulated polarized Airy beam

    NASA Astrophysics Data System (ADS)

    Zhao, Hongyang; Lin, Jie; Tan, Jiubin; Jin, Peng

    2016-07-01

    The focusing performance of a modulated polarized Airy beam is explored by using the Richards and Wolf vectorial diffraction model in a high numerical aperture system. The multiple foca appeared on the focal plane or along the optical axis when a complex amplitude modulating function was introduced. Two focusing spots with long-focal-depth were additionally observed due to the Airy beam and complex amplitude modulation. The distance between the focuses were changed from 1.15λ to 3.56λ with FWHM of 0.9λ for one-dimensional linear polarized incident beam and from 1.15λ to 3.64λ for two-dimensional beam. The multiple focusing spots are expected to apply in the field of optical trapping and particle acceleration.

  12. Spatiotemporal dynamics of counterpropagating Airy beams

    PubMed Central

    Wiersma, Noémi; Marsal, Nicolas; Sciamanna, Marc; Wolfersberger, Delphine

    2015-01-01

    We analyse theoretically the spatiotemporal dynamics of two incoherent counterpropagating Airy beams interacting in a photorefractive crystal under focusing conditions. For a large enough nonlinearity strength the interaction between the two Airy beams leads to light-induced waveguiding. The stability of the waveguide is determined by the crystal length, the nonlinearity strength and the beam’s intensities and is improved when comparing to the situation using Gaussian beams. We further identify the threshold above which the waveguide is no longer static but evolves dynamically either time-periodically or even chaotically. Above the stability threshold, each Airy-soliton moves erratically between privileged output positions that correspond to the spatial positions of the lobes of the counterpropagating Airy beam. These results suggest new ways of creating dynamically varying waveguides, optical logic gates and chaos-based computing. PMID:26315530

  13. Spatiotemporal dynamics of counterpropagating Airy beams

    NASA Astrophysics Data System (ADS)

    Wiersma, Noémi; Marsal, Nicolas; Sciamanna, Marc; Wolfersberger, Delphine

    2015-08-01

    We analyse theoretically the spatiotemporal dynamics of two incoherent counterpropagating Airy beams interacting in a photorefractive crystal under focusing conditions. For a large enough nonlinearity strength the interaction between the two Airy beams leads to light-induced waveguiding. The stability of the waveguide is determined by the crystal length, the nonlinearity strength and the beam’s intensities and is improved when comparing to the situation using Gaussian beams. We further identify the threshold above which the waveguide is no longer static but evolves dynamically either time-periodically or even chaotically. Above the stability threshold, each Airy-soliton moves erratically between privileged output positions that correspond to the spatial positions of the lobes of the counterpropagating Airy beam. These results suggest new ways of creating dynamically varying waveguides, optical logic gates and chaos-based computing.

  14. Image signal transmission with Airy beams.

    PubMed

    Liang, Yi; Hu, Yi; Song, Daohong; Lou, Cibo; Zhang, Xinzheng; Chen, Zhigang; Xu, Jingjun

    2015-12-01

    We propose and demonstrate an approach for image signal transmission based on self-accelerating Airy beams. The spatial information is encoded in the Fourier space through a 4-f telescope system, which can circumvent obstacles to realize a self-bending signal transmission. Furthermore, the information can be retrieved from the Airy beams after propagation through a disordered scattering medium. Our experimental results agree well with theoretical predictions. PMID:26625082

  15. Airy-type solitary wave in highly noninstantaneous Kerr media.

    PubMed

    Deng, Fu; Hong, Weiyi; Deng, Dongmei

    2016-07-11

    We investigate the dynamics of a decelerating Airy pulse in the highly noninstantaneous Kerr media. It is found that the deceleration of the Airy pulse can be counteracted by the highly noninstantaneous nonlinearity. When the power of the pulse is specifically chosen, the deceleration of the Airy pulse can be totally restrained, and an Airy-type solitary wave is observed within several dispersion lengths. PMID:27410868

  16. Elegant Hermite-Airy beams

    NASA Astrophysics Data System (ADS)

    Zhou, Guoquan; Zhang, Lijun; Ru, Guoyun

    2015-09-01

    As Ai(x)Ai(-x) can be approximated by \\text{exp}≤ft(-{{x}2}/2\\right) , a kind of elegant Hermite-Airy (EHA) beam that is similar to the elegant Hermite-Gaussian (EHG) beam is introduced in this paper. Analytical expression of the EHA beams passing through an ABCD paraxial optical system is derived. By using the method of numerical fitting, the approximate expressions of 02> , 04> , <\\Thetaj2> , <\\Thetaj4> , and 02\\Thetaj2> for an EHA beam are presented, respectively. When the transverse mode number is larger than 2, 02> , 04> , <\\Thetaj2> , <\\Thetaj4> , and 02\\Thetaj2> of an EHA beam are all larger than those of the EHG beam. Based on the higher-order intensity moments, one can calculate the beam propagation factor, the beam half width, and the kurtosis parameter of the EHA beam passing through an ABCD paraxial optical system. As a numerical example, the propagation characteristics of the EHA beam are demonstrated in free space. Moreover, the propagation properties of the EHA beam are compared with those of the corresponding EHG beam. The evolutionary process of the EHA beam is far slower than that of the corresponding EHG beam. The research denotes that the EHA beams can be used to describe specially distributed optical beams that can not be characterized by the existing EHG beam model. The EHA beam model enriches and replenishes the existing beam model.

  17. Ultrafast Airy beam optical parametric oscillator.

    PubMed

    Apurv Chaitanya, N; Kumar, S Chaitanya; Aadhi, A; Samanta, G K; Ebrahim-Zadeh, M

    2016-01-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm. PMID:27476910

  18. Ultrafast Airy beam optical parametric oscillator

    PubMed Central

    Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.

    2016-01-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm. PMID:27476910

  19. Ultrafast Airy beam optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.

    2016-08-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm.

  20. Temporal Airy pulses control cell poration

    NASA Astrophysics Data System (ADS)

    Courvoisier, S.; Götte, N.; Zielinski, B.; Winkler, T.; Sarpe, C.; Senftleben, A.; Bonacina, L.; Wolf, J. P.; Baumert, T.

    2016-07-01

    We show that spectral phase shaping of fs-laser pulses can be used to optimize laser-cell membrane interactions in water environment. The energy and peak intensity thresholds required for cell poration with single pulse in the nJ range can be significantly reduced (25% reduction in energy and 88% reduction in peak intensity) by using temporal Airy pulses, controlled by positive third order dispersion, as compared to bandwidth limited pulses. Temporal Airy pulses are also effective to control the morphology of the induced pores, with prospective applications from cellular to tissue opto-surgery and transfection.

  1. Bose-Einstein condensation of {alpha} particles and Airy structure in nuclear rainbow scattering

    SciTech Connect

    Ohkubo, S.; Hirabayashi, Y.

    2004-10-01

    It is shown that the dilute density distribution of {alpha} particles in nuclei can be observed in the Airy structure in nuclear rainbow scattering. We have analyzed {alpha}+{sup 12}C rainbow scattering to the 0{sub 2}{sup +} (7.65 MeV) state of {sup 12}C in a coupled-channel method with the precise wave functions for {sup 12}C. It is found that the enhanced Airy oscillations in the experimental angular distributions for the 0{sub 2}{sup +} state is caused by the dilute density distribution of this state in agreement for the idea of Bose-Einstein condensation of the three alpha particles.

  2. Airy, Sir George Biddell (1801-92)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A brilliant Cambridge mathematician (Senior Wrangler 1823, i.e. leader of the graduating mathematics class), Airy became the seventh Astronomer Royal in 1835 after a brief period as Lucasian Professor at Cambridge. His output was prodigious, and he published nearly 400 scientific papers and 150 reports on various scientific issues, such as the gauge of railways, spectacles to correct astigmatism,...

  3. Adding stress plot function to NASTRAN

    NASA Technical Reports Server (NTRS)

    Katoh, S.

    1978-01-01

    Stress plot function was developed and added to the NASTRAN level 15.5. Computed stress distribution can be displayed by this function, with vectors showing the principal stresses of the finite elements over the specified portions of the structure. NASTRAN is reviewed in the aspect of plotting capabilities. Stress tensor field is examined in preparation of stress display. Then the stress plot function as added to the NASTRAN is described. A sample plotout by this function is shown.

  4. Stress, fighting and neuroendocrine function.

    NASA Technical Reports Server (NTRS)

    Conner, R. L.; Levine, S.; Vernikos-Danellis, J.

    1971-01-01

    Plasma concentrations of pituitary adrenocorticotrophic hormone (ACTH) and adrenocortical steroids in rats after testing in the shock-induced fighting paradigm were examined. The investigations provide data consistent with the view that psychological aspects of the stressful situation are important in determining the effects of shock on physiological function. The data indicate that the pituitary-adrenal response can be attenuated by the expression of an organized pattern of behavior.

  5. Accelerating Airy-Gauss-Kummer localized wave packets

    NASA Astrophysics Data System (ADS)

    Zhong, Wei-Ping; Belić, Milivoj; Zhang, Yiqi; Huang, Tingwen

    2014-01-01

    A general approach to generating three-dimensional nondiffracting spatiotemporal solutions of the linear Schrödinger equation with an Airy-beam time-dependence is reported. A class of accelerating optical pulses with the structure of Airy-Gauss-Kummer vortex beams is obtained. Our results demonstrate that the optical field contributions to the Airy-Gauss-Kummer accelerating optical wave packets of the cylindrical symmetry can be characterized by the radial and angular mode numbers.

  6. Autobiography of Sir George Biddell Airy

    NASA Astrophysics Data System (ADS)

    Airy, George Biddell; Airy, Wilfred

    2010-06-01

    Preface; 1. Personal sketch of George Biddell Airy; 2. From his birth to his taking his B.A. degree; 3. At Trinity College, Cambridge; 4. At Cambridge Observatory; 5. At Greenwich Observatory, 1836-1846; 6. At Greenwich Observatory, 1846-1856; 7. At Greenwich Observatory, 1856-1866; 8. At Greenwich Observatory, 1866-1876; 9. At Greenwich Observatory to his resignation in 1881; 10. At the White House, Greewich, to his death; Appendix: List of printed papers; Index.

  7. Methodology of contact stress analysis of gearwheel by means of experimental photoelasticity.

    PubMed

    Frankovský, Peter; Ostertag, Oskar; Trebuňa, František; Ostertagová, Eva; Kelemen, Michal

    2016-06-20

    The subject of this paper is the analysis of contact stresses that occur between the teeth of a gear. The analysis was carried out by means of reflection photoelasticity, which is an experimental method rarely used in this field. Contact stresses assessed in the experiment are compared with values assessed through an analytical calculation while using the Airy stress function or Hertzian relations. PMID:27409110

  8. Controllable circular Airy beams via dynamic linear potential

    NASA Astrophysics Data System (ADS)

    Zhong, Hua; Zhang, Yiqi; Belić, Milivoj R.; Li, Changbiao; Wen, Feng; Zhang, Zhaoyang; Zhang, Yanpeng

    2016-04-01

    We investigate controllable spatial modulation of circular autofocusing Airy beams, under action of different dynamic linear potentials, both theoretically and numerically. We introduce a novel treatment method in which the circular Airy beam is represented as a superposition of narrow azimuthally-modulated one-dimensional Airy beams that can be analytically treated. The dynamic linear potentials are appropriately designed, so that the autofocusing effect can either be weakened or even eliminated when the linear potential exerts a "pulling" effect on the beam, or if the linear potential exerts a "pushing" effect, the autofocusing effect can be greatly strengthened. Numerical simulations agree with the theoretical results very well.

  9. Quasi-Airy beams along tunable propagation trajectories and directions.

    PubMed

    Qian, Yixian; Zhang, Site

    2016-05-01

    We present a theoretical and experimental exhibit that accelerates quasi-Airy beams propagating along arbitrarily appointed parabolic trajectories and directions in free space. We also demonstrate that such quasi-Airy beams can be generated by a tunable phase pattern, where two disturbance factors are introduced. The topological structures of quasi-Airy beams are readily manipulated with tunable phase patterns. Quasi-Airy beams still possess the characteristics of non-diffraction, self-healing to some extent, although they are not the solutions for paraxial wave equation. The experiments show the results are consistent with theoretical predictions. It is believed that the property of propagation along arbitrarily desired parabolic trajectories will provide a broad application in trapping atom and living cell manipulation. PMID:27137563

  10. AiryÕs Greenwich Staff

    NASA Astrophysics Data System (ADS)

    Chapman, A.

    2012-01-01

    One major research development in the history of astronomy, pioneered in particular by the SHA, is a shift from the concern with what the ÔgiantsÕ, such as Galileo or Newton, achieved to an examination of the wider spectrum of astronomical personnel. And one rich field of inquiry here is that body of men, and later of women, who earned their livings as assistant astronomers. It is, in fact, an abundantly documented area, including figures employed in Grand Amateur, university, and civic observatories, though without doubt the richest and longest-running body of data pertaining to what might be called the ÔAstronomersÕ GentlemenÕ comes from the archives of the Royal Observatory, Greenwich, especially for the years 1835 to 1881, when Sir George Biddell Airy was Astronomer Royal.

  11. Dynamical deformed Airy beams with arbitrary angles between two wings.

    PubMed

    Liang, Yi; Hu, Yi; Ye, Zhuoyi; Song, Daohong; Lou, Cibo; Zhang, Xinzheng; Xu, Jingjun; Morandotti, Roberto; Chen, Zhigang

    2014-07-01

    We study both numerically and experimentally the acceleration and propagation dynamics of 2D Airy beams with arbitrary initial angles between their "two wings." Our results show that the acceleration of these generalized 2D Airy beams strongly depends on the initial angles and cannot be simply described by the vector superposition principle (except for the normal case of a 90° angle). However, as a result of the "Hyperbolic umbilic" catastrophe (a two-layer caustic), the main lobes of these 2D Airy beams still propagate along parabolic trajectories even though they become highly deformed. Under such conditions, the peak intensity (leading energy flow) of the 2D Airy beams cannot be confined along the main lobe, in contrast to the normal 90° case. Instead, it is found that there are two parabolic trajectories describing the beam propagation: one for the main lobe, and the other for the peak intensity. Both trajectories can be readily controlled by varying the initial wing angle. Due to their self-healing property, these beams tend to evolve into the well-known 1D or 2D Airy patterns after a certain propagation distance. The theoretical analysis corroborates our experimental observations, and explains clearly why the acceleration of deformed Airy beams increases with the opening of the initial wing angle. PMID:25121433

  12. How mental stress affects endothelial function.

    PubMed

    Toda, Noboru; Nakanishi-Toda, Megumi

    2011-12-01

    Mental stress is an important factor contributing to recognized mechanisms underlying cardiovascular events. Among these, stress-related endothelial dysfunction is an early risk factor that predicts future development of severe cardiovascular disorders. Acute mental stress by a variety of tests impairs endothelial function in humans, although the opposite results have been reported by some investigators. Chronic stress always deteriorates endothelial function in humans and experimental animals. Stress hormones, such as glucocorticoids and pro-inflammatory cytokines, and endothelin-1 liberated in response to mental stress participate in endothelial dysfunction possibly via downregulation of endothelial nitric oxide synthase (eNOS) expression, eNOS inactivation, decreased nitric oxide (NO) actions, and increased NO degradation, together with vasoconstriction counteracting against NO-induced vasodilatation. Catecholamines do not directly affect endothelial function but impair its function when blood pressure elevation by the amines is sustained. Endogenous opioids favorably affect endothelial function, which counteract deteriorating effects of other stress hormones and mediators. Inhibition of cortisol and endothelin-1 production, prevention of pro-inflammatory mediator accumulation, hypnotics, mirthful laughter, humor orientation, and lifestyle modification would contribute to the prevention and treatment for stress-related endothelial dysfunction and future serious cardiovascular disease. PMID:21947555

  13. 75 FR 43816 - Amendment of Class E Airspace; Mount Airy, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ...This action amends Class E Airspace at Mount Airy, NC, to accommodate the additional airspace needed for the Standard Instrument Approach Procedures (SIAPs) developed for Mount Airy-Surry County...

  14. Generation and propagation dynamics of Airy beam with the tunable tail

    NASA Astrophysics Data System (ADS)

    Liu, Huilong; Lü, Yanfei; Xia, Jing; Pu, Xiaoyun; Zhang, Li

    2016-05-01

    We introduce a new kind of Airy beam called Airy beam with the tunable tail, which can be generated from the elliptical flat-topped Gaussian beam. The analytical formula of Airy beam with the tunable tail is derived. Airy beam with the single tail can be obtained by adjusting the ration of the beam width of elliptical flat-topped Gaussian beam. The tail length of Airy beam can be controlled by the order N of incident beam. The normalized intensity distributions of Airy beam with the tunable tail propagating in free space are studied, and the propagation dynamics of Airy beam with the single tail are investigated. Compared with the Airy beam generated from the fundamental Gaussian beam or the flat-topped Gaussian beam, some interesting and useful information has been found.

  15. Vessel extraction using the Buckmaster-Airy filter

    NASA Astrophysics Data System (ADS)

    Sanchez, Valentina

    2016-05-01

    A new and powerful technique for vessel extraction from biomedical images using the so called Buckmaster- Airy Filter is designed, prototyped and tested. The design, the prototyping and the testing were performed using computer algebra software, specifically the Maple package ImageTools. Some preliminary experiments were performed ant the results were excellent. Our new technique is based on partial differential equations.. Specifically two dimensional Airy diffusion equation and the two dimensional Buckmaster equation were used for designing the new Buckmaster-Airy Filter. Such new filter is able to enhance the quality of an image, producing simultaneously noise elimination, but without altering the edges of the image. The new Bukmaster-Airy filter is applied to the target image via discrete convolution. The results of some experiments of vessel extraction will be presented; and some lines for future research such as the possible implementation of the Buckmaster-Airy Filter as a new plugging for the program ImageJ, will be proposed.

  16. Airy-Kaup-Kupershmidt filters applied to digital image processing

    NASA Astrophysics Data System (ADS)

    Hoyos Yepes, Laura Cristina

    2015-09-01

    The Kaup-Kupershmidt operator is applied to the two-dimensional solution of the Airy-diffusion equation and the resulting filter is applied via convolution to image processing. The full procedure is implemented using Maple code with the package ImageTools. Some experiments were performed using a wide category of images including biomedical images generated by magnetic resonance, computarized axial tomography, positron emission tomography, infrared and photon diffusion. The Airy-Kaup-Kupershmidt filter can be used as a powerful edge detector and as powerful enhancement tool in image processing. It is expected that the Airy-Kaup-Kupershmidt could be incorporated in standard programs for image processing such as ImageJ.

  17. Improved Intrapulse Raman Scattering Control via Asymmetric Airy Pulses

    NASA Astrophysics Data System (ADS)

    Hu, Yi; Tehranchi, Amirhossein; Wabnitz, Stefan; Kashyap, Raman; Chen, Zhigang; Morandotti, Roberto

    2015-02-01

    We experimentally demonstrate the possibility of tuning the frequency of a laser pulse via the use of an Airy pulse-seeded soliton self-frequency shift. The intrinsically asymmetric nature of Airy pulses, typically featured by either leading or trailing oscillatory tails (relatively to the main lobe), is revealed through the nonlinear generation of both a primary and a secondary Raman soliton self-frequency shift, a phenomenon which is driven by the soliton fission processes. The resulting frequency shift can be carefully controlled by using time-reversed Airy pulses or, alternatively, by applying an offset to the cubic phase modulation used to generate the pulses. When compared with the use of conventional chirped Gaussian pulses, our technique brings about unique advantages in terms of both efficient frequency tuning and feasibility, along with the generation and control of multicolor Raman solitons with enhanced tunability. Our theoretical analysis agrees well with our experimental observations.

  18. Optical trapping and manipulation of Mie particles with Airy beam

    NASA Astrophysics Data System (ADS)

    Zhao, Ziyu; Zang, Weiping; Tian, Jianguo

    2016-02-01

    In this paper we calculate the radiation forces and moving trajectories of Mie particles induced by 1D Airy beams using the plane wave spectrum method and arbitrary beam theory. Numerical results show that both the transverse and the longitudinal radiation forces are deeply dependent on the relative refractive index, radii and positions of the scattering particles illuminated by the Airy beam. Due to the radiation forces, Mie particles with different radii and initial positions can be dragged into the nearest main intensity lobes, and move along parabolic trajectories in the direction of the Poynting vector. At the ends of these trajectories, in the presence of Brownian force, the trapped scattering particles show irregular Brownian movement near their equilibrium positions. This characteristic property of Airy beams enables optical sorting to be used more easily in the colloidal and biological sciences.

  19. Super-resolution imaging based on virtual Airy spot

    NASA Astrophysics Data System (ADS)

    Liu, Zhengjun; Guo, Cheng; Cui, Junning; Wu, Qun

    2015-02-01

    Based on the theoretical model of Airy spot, a method is proposed for improving the imaging speed from confocal microscopy. The virtual Airy spot is designed for obtaining the pattern on CCD at detecting plane. Here the size of the spot is determined by the parameters of imaging system and intensity data from point detector, which can receive data quicker than CCD. The treatment can improve the speed of imaging comparing with CCD at receiving end. The virtual structured detection is also utilized for generating high-resolution image. Some numerical simulation results are provided for demonstrating the validity of the proposed method.

  20. Complex Airy analysis of photoreflectance spectra for III-V semiconductors

    NASA Astrophysics Data System (ADS)

    Estrera, J. P.; Duncan, W. M.; Glosser, R.

    1994-03-01

    We present a detailed analysis of photoreflectance (PR) spectra of semiconductors using complex Airy functions and their derivatives. We demonstrate that photoreflectance spectra can be treated in terms of a single complex Airy function with an energy-dependent broadening parameter. We show analytically and numerically that this complex Airy PR treatment is functionally equivalent within field conditions appropriate for PR to the model of R. N. Bhattacharya, H. Shen, P. Parayanthal, F. H. Pollak, T. Coutts, and A. Aharoni [Phys. Rev. B 37, 4044 (1988)], where the effects of gradient electric field and non-flat-band modulation are treated explicitly. The equivalence occurs because the field gradient and non-flat-band modulation effects are included in our model in the energy dependence of the phenomenological broadening parameter Γ*=(Γ0/ħθ)exp[δ(ħω-Eg)], where ħω is the photon energy, Eg is the band-gap energy, Γ0 is the nominal broadening at the band-gap energy, and δ is a parameter directly proportional to the electric-field gradient and modulation between two finite fields. The major utility of our model is that a single effective layer can be treated instead of a more computationally intensive laminar model. We apply our complex Airy model to bulk semiconductors such as GaAs, InP, and InxGa1-xAs. In the photoreflectance spectra of these semiconductors, our model considers three distinct but convolved features at E0 which represent the light- and heavy-hole valence bands and an exciton-impurity feature below E0. At E0+Δ0 our model considers two features which are related to the spin-orbit-split valence band and a second state just below this critical point. For GaAs, we determined from our PR modeling that the band-gap energy for these films was 1.422+/-0.003 eV, which agreed, within experimental error, with the band-gap energy measured by room-temperature photoluminescence. A feature was found below the E0 gap in the GaAs samples with energies

  1. Photorefractive and computational holography in the experimental generation of Airy beams

    NASA Astrophysics Data System (ADS)

    Suarez, Rafael A. B.; Vieira, Tarcio A.; Yepes, Indira S. V.; Gesualdi, Marcos R. R.

    2016-05-01

    In this paper, we present the experimental generation of Airy beams via computational and photorefractive holography. Experimental generation of Airy beams using conventional optical components presents several difficulties and a practically infeasible. Thus, the optical generation of Airy beams has been made from the optical reconstruction of a computer generated hologram implemented by a spatial light modulator. In the photorefractive holography technique, being used for the first time to our knowledge, the hologram of an Airy beam is constructed (recorded) and reconstructed (read) optically in a nonlinear photorefractive medium. The Airy beam experimental realization was made by a setup of computational and photorefractive holography using a photorefractive Bi12 TiO20 crystal as holographic recording medium. Airy beams and Airy beam arrays were obtained experimentally in accordance with the predicted theory; with excellent prospects for applications in optical trapping and optical communications systems.

  2. Two-dimensional χ^2 solitons generated by the downconversion of Airy waves

    NASA Astrophysics Data System (ADS)

    Mayteevarunyoo, Thawatchai; Malomed, Boris A.

    2016-07-01

    Conversion of truncated Airy waves (AWs) carried by the second-harmonic (SH) component into axisymmetric $\\chi^{2}$ solitons is considered in the 2D system with the quadratic nonlinearity. The spontaneous conversion is driven by the parametric instability of the SH wave. The input in the form of the AW vortex is considered too. As a result, one, two, or three stable solitons emerge in a well-defined form, unlike the recently studied 1D setting, where the picture is obscured by radiation jets. Shares of the total power captured by the emerging solitons and conversion efficiency are found as functions of parameters of the AW input.

  3. Two-dimensional χ2 solitons generated by the downconversion of Airy waves.

    PubMed

    Mayteevarunyoo, Thawatchai; Malomed, Boris A

    2016-07-01

    Conversion of truncated Airy waves (AWs) carried by the second-harmonic (SH) component into axisymmetric χ2 solitons is considered in a 2D system with quadratic nonlinearity. The spontaneous conversion is driven by the parametric instability of the SH wave. The input in the form of the AW vortex is also considered. As a result, one, two, or three stable solitons emerge in a well-defined form, unlike the recently studied 1D setting, where the picture is obscured by radiation jets. Shares of the total power captured by the emerging solitons and conversion efficiency are found as functions of parameters of the AW input. PMID:27367065

  4. Transient thermal stress analysis of a laminated composite beam

    SciTech Connect

    Tanigawa, Y.; Murakami, H.; Ootao, Y. California Univ., La Jolla Osaka Prefectural Industrial Technology Research Institute )

    1989-01-01

    This paper considers a transient thermal stress analysis of a laminated beam made of different materials in multilayers. To simplify the problem, the heat conduction problem is treated as a one-dimensional case in the direction of thickness; then, the transient temperature solution is evaluated using the Laplace transform method. For the thermoelastic fields, thermal stress distributions are obtained using the elementary beam theory and Airy's thermal stress function method. As an example, numerical calculations are carried out for a laminated beam made of five layers, and the numerical results are examined.

  5. Experimental observation and analysis of all-fiber plasmonic double Airy beams.

    PubMed

    Guan, Chunying; Ding, Ming; Shi, Jinhui; Hua, Ping; Wang, Pengfei; Yuan, Libo; Brambilla, Gilberto

    2014-07-28

    The propagation dynamics of all-fiber plasmonic double parallel and orthogonal Airy beams are experimentally demonstrated. Two slits and groove arrays were fabricated by focused ion beam (FIB) milling on the gold coated end facet of an optical fiber to generate two Airy beams simultaneously. Sub-wavelength self-focusing of double parallel Airy beams in free space is experimentally verified. Effects of geometrical parameters on the intensity profiles of the focal spot are analyzed in detail. The characteristics at the junction of the two main lobes can be adjusted by controlling the initial phase difference of the two Airy beams. The propagation of two orthogonal Airy beams is also experimentally investigated. Multi-Airy beams are of importance to realize all-fiber optical trapping, fiber integrated devices, and laser shaping. PMID:25089455

  6. What is the diffraction limit? From Airy to Abbe using direct numerical integration

    NASA Astrophysics Data System (ADS)

    Calm, Y. M.; Merlo, J. M.; Burns, M. J.; Kempa, K.; Naughton, M. J.

    The resolution of a conventional optical microscope is sometimes taken from Airy's point spread function (PSF), 0 . 61 λ / NA , and sometimes from Abbe, λ / 2 NA , where NA is the numerical aperture, however modern fluorescence and near-field optical microscopies achieve spatial resolution far better than either of these limits. There is a new category of 2D metamaterials called planar optical elements (POEs), which have a microscopic thickness (< λ), macroscopic transverse dimensions (> 100 λ), and are composed of an array of nanostructured light scatterers. POEs are found in a range of micro- and nano-photonic technologies, and will influence the future optical nanoscopy. With this pretext, we shed some light on the 'diffraction limit' by numerically evaluating Kirchhoff's scalar formulae (in their exact form) and identifying the features of highly non-paraxial, 3D PSFs. We show that the Airy and Abbe criteria are connected, and we comment on the design rules for a particular type of POE: the flat lens. This work is supported by the W. M. Keck Foundation.

  7. Propagation of Airy Gaussian vortex beams in uniaxial crystals

    NASA Astrophysics Data System (ADS)

    Weihao, Yu; Ruihuang, Zhao; Fu, Deng; Jiayao, Huang; Chidao, Chen; Xiangbo, Yang; Yanping, Zhao; Dongmei, Deng

    2016-04-01

    The propagation dynamics of the Airy Gaussian vortex beams in uniaxial crystals orthogonal to the optical axis has been investigated analytically and numerically. The propagation expression of the beams has been obtained. The propagation features of the Airy Gaussian vortex beams are shown with changes of the distribution factor and the ratio of the extraordinary refractive index to the ordinary refractive index. The correlations between the ratio and the maximum intensity value during the propagation, and its appearing distance have been investigated. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374108, 11374107, 10904041, and 11547212), the Foundation of Cultivating Outstanding Young Scholars of Guangdong Province, China, the CAS Key Laboratory of Geospace Environment, University of Science and Technology of China, the National Training Program of Innovation and Entrepreneurship for Undergraduates (Grant No. 2015093), and the Science and Technology Projects of Guangdong Province, China (Grant No. 2013B031800011).

  8. Propagation of time-truncated Airy-type pulses in media with quadratic and cubic dispersion.

    PubMed

    Borda-Hernández, José A; Zamboni-Rached, Michel; Shaarawi, Amr; Besieris, Ioannis M

    2015-10-01

    In this paper, we describe analytically the propagation of Airy-type pulses truncated by a finite-time aperture when second- and third-order dispersion effects are considered. The mathematical method presented here, which is based on the superposition of exponentially truncated Airy pulses, is very effective and allows us to avoid the use of time-consuming numerical simulations. We analyze the behavior of the time-truncated ideal Airy pulse and also the interesting case of a time-truncated Airy pulse with a "defect" in its initial profile, which reveals the self-healing property of this kind of pulse solution. PMID:26479932

  9. Measurement of residual stresses using fracture mechanics weight functions

    SciTech Connect

    Fan, Y.

    2000-10-01

    A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed.

  10. 75 FR 14381 - Amendment of Class E Airspace; Mount Airy, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ...This action proposes to amend Class E Airspace at Mount Airy, NC, to accommodate the additional airspace needed for the Standard Instrument Approach Procedures (SIAPs) developed for Mount Airy-Surry County Airport. This action enhances the safety and airspace management of Instrument Flight Rules (IFR) operations at the...

  11. The Function of Stress in English.

    ERIC Educational Resources Information Center

    Deutsch, George B.

    In an analysis of stress and intonation, stress is shown to distinguish semantic and grammatical meaning on every level of language. It is suggested that the distinction between stress and intonation is particularly important in teaching English as a second language. Written texts and fabricated examples of dialogue are used, with a focus on…

  12. Racism-Related Stress, General Life Stress, and Psychological Functioning among Black American Women

    ERIC Educational Resources Information Center

    Pieterse, Alex L.; Carter, Robert T.; Ray, Kilynda V.

    2013-01-01

    The relationship between general life stress, perceived racism, and psychological functioning was explored in a sample of 118 Black American women. Findings indicate that racism-related stress was not a significant predictor of psychological functioning when controlling for general life stress. Perceived racism was positively associated with…

  13. Chronic stress and sexual function in women

    PubMed Central

    Hamilton, Lisa Dawn; Meston, Cindy M.

    2014-01-01

    Introduction Chronic stress is known to have negative effects on reproduction, but little is known about how it affects the sexual response cycle. The present study examined the relationship between chronic stress and sexual arousal and the mechanisms that mediate this relationship. Aim To test the relationship between chronic stress and sexual arousal and identify mechanisms that may explain this relationship. We predicted that women experiencing high levels of chronic stress would show lower levels of genital arousal & DHEAS and higher levels of cortisol and cognitive distraction compared to women with average levels of stress. Methods Women who were categorized as high in chronic stress (high stress group, n = 15) or average in chronic stress (average stress group; n = 15) provided saliva samples and watched an erotic film while having their genital and psychological arousal measured. Main Outcome Measures Main outcome measures were vaginal pulse amplitude, psychological arousal, salivary cortisol, salivary DHEAS, and heart rate and compared them between women with high and average levels of chronic stress. Results Women in the high stress group had lower levels of genital, but not psychological arousal, had higher levels of cortisol, and reported more distraction during the erotic film than women in the average stress group. The main predictor of decreased genital sexual arousal was participants’ distraction scores. Conclusions High levels of chronic stress were related to lower levels of genital sexual arousal. Both psychological (distraction) and hormonal (increased cortisol) factors were related to the lower levels of sexual arousal seen in women high in chronic stress, but distraction was the only significant predictor when controlling for other variables. PMID:23841462

  14. Stress distributions and stress intensity factors in ceramic roller bearing rings

    NASA Astrophysics Data System (ADS)

    Müller, W. H.

    1995-06-01

    A method is presented which allows to compute the stress intensity factors (SIFs) of a ceramic roller bearing ring with a surface flaw. First, the stresses due to mechanical loads applied to the surfaces of the undamaged ring are computed, using Michell's expression for Airy's stress function in polar coordinates ([l]). Second, the stress intensity factors of the flaw are obtained using Tada's additivity principle ([2]), namely by integration of the point force solution for the SIF of a surface crack with the aforementioned stresses as input parameter. To illustrate the procedure, the special case of a ring with a surface flaw which is loaded by six equidistantly spaced cylindrical rollers will be studied numerically.

  15. Quantum polarization fluctuations of an Airy beam in turbulent atmosphere in a slant path.

    PubMed

    Yin, Xia; Zhang, Licheng

    2016-07-01

    Polarization of light has many applications in quantum information processing, including quantum teleportation and dense coding. In this paper, we investigate the polarization fluctuations of Airy beams propagating in a slant turbulent channel under the "few-photon" limit. Using the quantum Stokes parameters and the quantum degree of polarization, we demonstrate that the degree of polarization of Airy beams increases significantly with the large number of the detection photons, and a higher photon-number level can retain the stability of polarization. Numerical simulations show that the longer propagation distance and the stronger turbulence will lead to less oscillatory behaviors and a decrease in the polarization degree of Airy beams, but a bigger exponential truncation factor will cause an increase in the polarization degree of Airy beams. In contrast with Gaussian beams, the degree of polarization of Airy beams is less affected by atmospheric turbulence and propagation distance under the same conditions, which means that Airy beams possess a resilient ability against turbulence-induced perturbations. These results indicate that Airy beams have great potential for applications in long-distance free-space optical communications to improve the performance of a polarization-encoded free-space quantum communication system. PMID:27409692

  16. Analytical study of the self-healing property of Airy beams

    NASA Astrophysics Data System (ADS)

    Chu, Xiuxiang; Zhou, Guoquan; Chen, Ruipin

    2012-01-01

    An analytical expression for the optical field of an Airy beam partially blocked by an opaque obstacle is derived. The self-healing properties of the Airy beam are studied and discussed in detail. The study shows that the self-healing process of the Airy beam is affected by many factors such as the opaque obstacle size, propagation distance, wavelength, and parameters of the Airy beam. The self-healing process is caused by the convergence of energy from the side to the position of the opaque obstacle and is finished when the convergence of energy flow disappears. When the propagation distance is short, the main lobe of the Airy beam is affected by the obstruction located near the main lobe. When the propagation distance is long, the main lobe of the Airy beam can be affected by the obstruction located far away from the main lobe. The result agrees with the existing results and can be explained by the caustic of the Airy beam.

  17. Control on the anomalous interactions of Airy beams in nematic liquid crystals.

    PubMed

    Shen, Ming; Li, Wei; Lee, Ray-Kuang

    2016-04-18

    We reveal a controllable manipulation of anomalous interactions between Airy beams in nonlocal nematic liquid crystals numerically. With the help of an in-phase fundamental Gaussian beam, attraction between in-phase Airy beams can be suppressed or become a repulsive one to each other; whereas the attraction can be strengthened when the Gaussian beam is out-of-phase. In contrast to the repulsive interaction in local media, stationary bound states of breathing Airy soliton pairs are found in nematic liquid crystals. PMID:27137288

  18. The Plant Heat Stress Transcription Factors (HSFs): Structure, Regulation, and Function in Response to Abiotic Stresses

    PubMed Central

    Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Luo, De-Xu; Gong, Zhen-Hui; Lu, Ming-Hui

    2016-01-01

    Abiotic stresses such as high temperature, salinity, and drought adversely affect the survival, growth, and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological, and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs), including heat stress transcription factors (HSFs). HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps). In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention. PMID:26904076

  19. Extended Kantorovich method for local stresses in composite laminates upon polynomial stress functions

    NASA Astrophysics Data System (ADS)

    Huang, Bin; Wang, Ji; Du, Jianke; Guo, Yan; Ma, Tingfeng; Yi, Lijun

    2016-06-01

    The extended Kantorovich method is employed to study the local stress concentrations at the vicinity of free edges in symmetrically layered composite laminates subjected to uniaxial tensile load upon polynomial stress functions. The stress fields are initially assumed by means of the Lekhnitskii stress functions under the plane strain state. Applying the principle of complementary virtual work, the coupled ordinary differential equations are obtained in which the solutions can be obtained by solving a generalized eigenvalue problem. Then an iterative procedure is established to achieve convergent stress distributions. It should be noted that the stress function based extended Kantorovich method can satisfy both the traction-free and free edge stress boundary conditions during the iterative processes. The stress components near the free edges and in the interior regions are calculated and compared with those obtained results by finite element method (FEM). The convergent stresses have good agreements with those results obtained by three dimensional (3D) FEM. For generality, various layup configurations are considered for the numerical analysis. The results show that the proposed polynomial stress function based extended Kantorovich method is accurate and efficient in predicting the local stresses in composite laminates and computationally much more efficient than the 3D FEM.

  20. Effects of work stress and home stress on autonomic nervous function in Japanese male workers

    PubMed Central

    MAEDA, Eri; IWATA, Toyoto; MURATA, Katsuyuki

    2014-01-01

    Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Although previous studies have focused mainly on stress at work (work stress), the association between autonomic function and stress at home (home stress) is still poorly understood. The purpose was to clarify the effect of work/home stress on autonomic function in 1,809 Japanese male workers. We measured corrected QT (QTc) interval and QT index on the electrocardiogram along with blood pressure and heart rate. Participants provided self-reported information about the presence/absence of work/home stress and the possible confounders affecting QT indicators. Home stress was related positively to QT index (p=0.040) after adjusting for the possible confounders, though work stress did not show a significant relation to QTc interval or QT index. The odds ratio of home stress to elevated QT index (≥105) was 2.677 (95% CI, 1.050 to 6.822). Work/home stress showed no significant relation to blood pressure or heart rate. These findings suggest that autonomic imbalance, readily assessed by QT indicators, can be induced by home stress in Japanese workers. Additional research is needed to identify different types of home stress that are strongly associated with autonomic imbalance. PMID:25382383

  1. Psychological stress and epidermal barrier function.

    PubMed

    Orion, Edith; Wolf, Ronni

    2012-01-01

    The skin is the organ that acts as a barrier between the outer and inner environments of the body. It is thus exposed not only to a wide variety of physical, chemical, and thermal insults from the outside world but also to inner endogenous stimuli. Stress, once an abstract psychologic phenomenon, has taken research's center stage in recent years. The "mind-body connection" is now less of an obscure New Age term and more of an elaborate physiologic pathway by which bilateral communication occurs between body and brain. Dermatologists and dermatologic patients have long acknowledged the effect of stress on the skin and its capability to initiate, maintain, or exacerbate several skin diseases. Because disruption of epidermal barrier integrity may be important in the development of some common skin diseases, it is crucial to understand its vulnerability to psychologic stress. PMID:22507042

  2. AIRY: a complete tool for the simulation and the reconstruction of astronomical images

    NASA Astrophysics Data System (ADS)

    La Camera, Andrea; Carbillet, Marcel; Olivieri, Chiara; Boccacci, Patrizia; Bertero, Mario

    2012-07-01

    The Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CADS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a specific task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and Richardson-Lucy. Several modules of AIRY have been improved and, in particular, the one used for the extraction and extrapolatioThe Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CAOS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a speci_c task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and

  3. Quantitative comparison of self-healing ability between Bessel–Gaussian beam and Airy beam

    SciTech Connect

    Wen, Wei; Chu, Xiuxiang

    2015-09-15

    The self-healing ability during propagation process is one of the most important properties of non-diffracting beams. This ability has crucial advantages to light sheet-based microscopy to reduce scattering artefacts, increase the quality of the image and enhance the resolution of microscopy. Based on similarity between two infinite-dimensional complex vectors in Hilbert space, the ability to a Bessel–Gaussian beam and an Airy beam have been studied and compared. Comparing the evolution of the similarity of Bessel–Gaussian beam with Airy beam under the same conditions, we find that Bessel–Gaussian beam has stronger self-healing ability and is more stable than that of Airy beam. To confirm this result, the intensity profiles of Bessel–Gaussian beam and Airy beam with different similarities are numerically calculated and compared.

  4. Guiding ultraslow weak-light bullets with Airy beams in a coherent atomic system

    NASA Astrophysics Data System (ADS)

    Hang, Chao; Huang, Guoxiang

    2014-01-01

    We investigate the possibility of guiding stable ultraslow weak-light bullets by using Airy beams in a cold, lifetime-broadened four-level atomic system via electromagnetically induced transparency (EIT). We show that under EIT condition the light bullet with ultraslow propagating velocity and extremely low generation power formed by the balance between diffraction and nonlinearity in the probe field can be not only stabilized but also steered by the assisted field. In particular, when the assisted field is taken to be an Airy beam, the light bullet can be trapped into the main lobe of the Airy beam, propagate ultraslowly in longitudinal direction, accelerate in transverse directions, and move along a parabolic trajectory. We further show that the light bullet can bypass an obstacle when guided by two sequential Airy beams. A technique for generating ultraslow helical weak-light bullets is also proposed.

  5. Propagation of Airy-Gaussian beams in a chiral medium

    NASA Astrophysics Data System (ADS)

    Deng, Fu; Yu, Weihao; Huang, Jiayao; Zhao, Ruihuang; Lin, Jiong; Deng, Dongmei

    2016-04-01

    We have expressed and investigated the propagation of Airy-Gaussian beams (AiGBs) in a chiral medium analytically. It is shown that AiGBs split into two components, i.e., the left circularly polarized (LCP) beams and the right circularly polarized (RCP) beams, which have a different propagation trajectory and are affected by the chiral parameter γ and the distribution factor χ0. It is found that the LCP beams accelerate faster than the RCP beams during propagation, and are influenced by the chiral parameter. With an increase in the chiral parameter, the acceleration of the LCP beams increases, but that of the RCP beams decreases. So, it is significant that we can control the self-acceleration of AiGBs by varying the chiral parameter and the distribution factor.

  6. Interaction of Airy-Gaussian beams in Kerr media

    NASA Astrophysics Data System (ADS)

    Peng, Yulian; Peng, Xi; Chen, Bo; Zhou, Meiling; Chen, Chidao; Deng, Dongmei

    2016-01-01

    We study the interaction of the Airy-Gaussian (AiG) beams by using the numerical simulations with the split-step Fourier method. The results show that the single breathers and breather pairs can be formed in the condition with interaction. The breathers can be formed with the enough intensity of interactive beams. By adjusting the parameters of amplitude, interval, phase and χ0, we find that the interaction of the two beams is the strongest with in-phase and out-of-phase cases, especially in the shorter distance. Moreover, both the interaction intensity and the location, the interaction happens, can be changed by adjusting the distribution factor χ0 of the beams. It is notable that the various propagation directions of the beams can be obtained by changing the phase, at the same situation, when the interval of the two beams becomes narrower, the phase plays an important role of controlling the direction of the accelerated spot.

  7. Polarization-controllable Airy beams generated via a photoaligned director-variant liquid crystal mask.

    PubMed

    Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing

    2015-01-01

    Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories. PMID:26626737

  8. Polarization-controllable Airy beams generated via a photoaligned director-variant liquid crystal mask

    PubMed Central

    Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing

    2015-01-01

    Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories. PMID:26626737

  9. Polarization-controllable Airy beams generated via a photoaligned director-variant liquid crystal mask

    NASA Astrophysics Data System (ADS)

    Wei, Bing-Yan; Chen, Peng; Hu, Wei; Ji, Wei; Zheng, Li-Yang; Ge, Shi-Jun; Ming, Yang; Chigrinov, Vladimir; Lu, Yan-Qing

    2015-12-01

    Researches on Airy beams have grown explosively since the first demonstration in 2007 due to the distinguishing properties of nondiffraction, transverse acceleration and self-healing. To date, a simple and compact approach for generating Airy beams in high quality and efficiency has remained challenging. Here, we propose and demonstrate a liquid crystal (LC) polarization Airy mask (PAM) featured by spatially variant LC azimuthal director. The PAM is fabricated through photoaligning LC via a polarization-sensitive alignment agent suophonic azo dye SD1. Thanks to the special design, a novel feature of polarization-controllable switch between dual Airy beams of orthogonal circular polarization is presented. The molecular-level continuity of LC director significantly improves the quality and efficiency of resultant Airy beams. Besides, the PAM can handle intense light due to the absence of absorptive electrodes. Additional merits of compact size, low cost and broad wavelength tolerance are also exhibited. This work settles a fundamental requirement for Airy beam applications of optical manipulations, biology science and even some uncharted territories.

  10. Enhanced and unusual angle-dependent optical forces exerted on Mie particles by Airy surface plasmon wave

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Xue, Yanli; Li, Jiafang; Li, Zhi-Yuan

    2016-08-01

    In this paper, using an angular spectrum method, we develop an analytical theory for Airy surface plasmon wave excited in a classical Kretschmann setup. It is found that the center of an Airy surface plasmon polariton (SPP) wave has a giant positive lateral shift, and the sidelobes move forward along the surface. The intensity of the Airy SPP wave is greatly enhanced, the corresponding optical forces can be enhanced by more than one order of magnitude. Importantly, we show that the sidelobes of the Airy SPP beam can lead to the splitting of optical force spectra with the variation of incident angle, which is accompanied by strong oscillations emerging at the optimal metal layer thickness. Moreover, the effects of multiple scatterings of the Airy SPP wave between the particle and the metal layer are also discussed. The theoretical analysis could open up new perspectives for the applications of Airy beam in optical manipulation and surface-enhanced Raman scattering.

  11. Prenatal stress alters amygdala functional connectivity in preterm neonates.

    PubMed

    Scheinost, Dustin; Kwon, Soo Hyun; Lacadie, Cheryl; Sze, Gordon; Sinha, Rajita; Constable, R Todd; Ment, Laura R

    2016-01-01

    Exposure to prenatal and early-life stress results in alterations in neural connectivity and an increased risk for neuropsychiatric disorders. In particular, alterations in amygdala connectivity have emerged as a common effect across several recent studies. However, the impact of prenatal stress exposure on the functional organization of the amygdala has yet to be explored in the prematurely-born, a population at high risk for neuropsychiatric disorders. We test the hypothesis that preterm birth and prenatal exposure to maternal stress alter functional connectivity of the amygdala using two independent cohorts. The first cohort is used to establish the effects of preterm birth and consists of 12 very preterm neonates and 25 term controls, all without prenatal stress exposure. The second is analyzed to establish the effects of prenatal stress exposure and consists of 16 extremely preterm neonates with prenatal stress exposure and 10 extremely preterm neonates with no known prenatal stress exposure. Standard resting-state functional magnetic resonance imaging and seed connectivity methods are used. When compared to term controls, very preterm neonates show significantly reduced connectivity between the amygdala and the thalamus, the hypothalamus, the brainstem, and the insula (p < 0.05). Similarly, when compared to extremely preterm neonates without exposure to prenatal stress, extremely preterm neonates with exposure to prenatal stress show significantly less connectivity between the left amygdala and the thalamus, the hypothalamus, and the peristriate cortex (p < 0.05). Exploratory analysis of the combined cohorts suggests additive effects of prenatal stress on alterations in amygdala connectivity associated with preterm birth. Functional connectivity from the amygdala to other subcortical regions is decreased in preterm neonates compared to term controls. In addition, these data, for the first time, suggest that prenatal stress exposure amplifies these

  12. Effects of Acute Laboratory Stress on Executive Functions

    PubMed Central

    Starcke, Katrin; Wiesen, Carina; Trotzke, Patrick; Brand, Matthias

    2016-01-01

    Recent research indicates that stress can affect executive functioning. However, previous results are mixed with respect to the direction and size of effects, especially when considering different subcomponents of executive functions. The current study systematically investigates the effects of stress on the five components of executive functions proposed by Smith and Jonides (1999): attention and inhibition; task management; planning; monitoring; and coding. Healthy participants (N = 40) were either exposed to the computerized version of the Paced Auditory Serial Addition Test as a stressor (N = 20), or to a rest condition (N = 20). Stress reactions were assessed with heart rate and subjective measures. After the experimental manipulation, all participants performed tasks that measure the different executive functions. The manipulation check indicates that stress induction was successful (i.e., the stress group showed a higher heart rate and higher subjective responses than the control group). The main results demonstrate that stressed participants show a poorer performance compared with unstressed participants in all executive subcomponents, with the exception of monitoring. Effect sizes for the tasks that reveal differences between stressed and unstressed participants are high. We conclude that the laboratory stressor used here overall reduced executive functioning. PMID:27065926

  13. Regulation of the Adrenal Cortex Function During Stress

    NASA Technical Reports Server (NTRS)

    Soliman, K. F. A.

    1978-01-01

    A proposal to study the function of the adrenal gland in the rat during stress is presented. In the proposed project, three different phases of experimentation will be undertaken. The first phase includes establishment of the circadian rhythm of both brain amines and glucocoticoids, under normal conditions and under chronic and acute stressful conditions. The second phase includes the study of the pharmacokinetics of glucocorticoid binding under normal and stress conditions. The third phase includes brain uptake and binding under different experimental conditions. In the outlined experiments brain biogenic amines will be evaluated, adrenal functions will be measured and stress effect on those parameters will be studied. It is hoped that this investigation can explain some of the complex relationships between the brain neurotransmitter and adrenal function.

  14. ROS Function in Redox Signaling and Oxidative Stress

    PubMed Central

    Schieber, Michael; Chandel, Navdeep S.

    2014-01-01

    Oxidative stress refers to elevated intracellular levels of reactive oxygen species (ROS) that cause damage to lipids, proteins and DNA. Oxidative stress has been linked to a myriad of pathologies. However, elevated ROS are also signaling molecules i.e. redox biology that maintain physiological functions. In this review we discuss the two faces of ROS, redox signaling and oxidative stress, and their contribution to both physiological and pathological conditions. Redox biology refers to low levels of ROS that activate signaling pathways to initiate biological processes while oxidative stress denotes high levels of ROS that incur damage to DNA, protein or lipids. Thus, the response to ROS displays hormesis. The In this review, we argue that redox biology, rather than oxidative stress, underlies physiological and pathological conditions. PMID:24845678

  15. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2011-01-01

    A method for the production of functional proteins including hormones by renal cells in a three dimensional culturing process responsive to shear stress uses a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-.alpha.-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D.sub.3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating an in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  16. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2007-01-01

    The present invention provides a method for production of functional proteins including hormones by renal cells in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-a-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  17. Production of functional proteins: balance of shear stress and gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Kaysen, James Howard (Inventor)

    2004-01-01

    The present invention provides a method for production of functional proteins including hormones by renal cells in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-a-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel.

  18. Stability analysis of Reynolds stress response functional candidates

    SciTech Connect

    Dafinger, M.; Hallatschek, K.; Itoh, K.

    2013-04-15

    Complete information on the behavior of zonal flows in turbulence systems is coded in the turbulent stress response to the respective flow pattern. We show that turbulence stress response functionals containing only the linear first order wavenumber dependence on the flow pattern result in unstable structures up to the system size. A minimal augmentation to reproduce the flow patterns observed in turbulence simulations is discussed.

  19. Evolution of the ring Airy Gaussian beams with a spiral phase in the Kerr medium

    NASA Astrophysics Data System (ADS)

    Chen, Bo; Chen, Chidao; Peng, Xi; Peng, Yulian; Zhou, Meiling; Deng, Dongmei; Guo, Hong

    2016-05-01

    Nonlinear optical phenomena are of great practical interest in optics. The evolution of ring Airy Gaussian beams with a spiral phase in the nonlinear Kerr medium is investigated using the nonlinear Schrödinger equation. Numerical simulations indicate that the distribution factor b can influence the formation of the ring Airy Gaussian beams. Results show that the beams can be oscillating, and the light filament can be achieved under appropriate laser input power. On the other hand, the evolution of the ring Airy Gaussian beams with a spiral phase in the nonlinear Kerr medium can be implemented, and the numerical simulations of the holographic generation of the ring Airy Gaussian vortex beams propagated in the medium demonstrate that the vortex can be preserved along the propagation. The Poynting vector shows that the energy flow of the ring Airy Gaussian beams flows in the opposite direction on both sides of the focus plane; however, for beams with a spiral phase, the flow direction remains the same; the energy flow can rotate in opposite directions on both sides of the focal plane.

  20. Computer program for Bessel and Hankel functions

    NASA Technical Reports Server (NTRS)

    Kreider, Kevin L.; Saule, Arthur V.; Rice, Edward J.; Clark, Bruce J.

    1991-01-01

    A set of FORTRAN subroutines for calculating Bessel and Hankel functions is presented. The routines calculate Bessel and Hankel functions of the first and second kinds, as well as their derivatives, for wide ranges of integer order and real or complex argument in single or double precision. Depending on the order and argument, one of three evaluation methods is used: the power series definition, an Airy function expansion, or an asymptotic expansion. Routines to calculate Airy functions and their derivatives are also included.

  1. Cytokines and macrophage function in humans - role of stress

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, Gerald (Principal Investigator)

    1996-01-01

    We have begun this study to commence the determination of the role of mild chronic stress in the effects of space flight on macrophage/monocyte function, a component of the immune response. Medical students undergoing regular periods of stress and relaxation have been shown to be an excellent model for determining the effects of stress on immune responses. We have begun using this model using the macrophage/monocyte as model leukocyte. The monocyte/macrophage plays a central role in immunoregulation. The studies to be included in this three year project are the effects of stress on: (1) interactions of monocytes with microbes, (2) monocyte production of cytokines, (3) monocyte phagocytosis and activity, and (4) monocyte expression of cell surface antigens important in immune responses. Stress hormone levels will also be carried out to determine if there is a correlation between stress effects on immune responses and hormonal levels. Psychological testing to insure subjects are actually stressed or relaxed at the time of testing will also be carried out. The results obtained from the proposed studies should be comparable with space flight studies with whole animals and isolated cell cultures. When complete this study should allow the commencement of the establishment of the role of stress as one compartment of the induction of immune alterations by space flight.

  2. Polyamines function in stress tolerance: from synthesis to regulation

    PubMed Central

    Liu, Ji-Hong; Wang, Wei; Wu, Hao; Gong, Xiaoqing; Moriguchi, Takaya

    2015-01-01

    Plants are challenged by a variety of biotic or abiotic stresses, which can affect their growth and development, productivity, and geographic distribution. In order to survive adverse environmental conditions, plants have evolved various adaptive strategies, among which is the accumulation of metabolites that play protective roles. A well-established example of the metabolites that are involved in stress responses, or stress tolerance, is the low-molecular-weight aliphatic polyamines, including putrescine, spermidine, and spermine. The critical role of polyamines in stress tolerance is suggested by several lines of evidence: firstly, the transcript levels of polyamine biosynthetic genes, as well as the activities of the corresponding enzymes, are induced by stresses; secondly, elevation of endogenous polyamine levels by exogenous supply of polyamines, or overexpression of polyamine biosynthetic genes, results in enhanced stress tolerance; and thirdly, a reduction of endogenous polyamines is accompanied by compromised stress tolerance. A number of studies have demonstrated that polyamines function in stress tolerance largely by modulating the homeostasis of reactive oxygen species (ROS) due to their direct, or indirect, roles in regulating antioxidant systems or suppressing ROS production. The transcriptional regulation of polyamine synthesis by transcription factors is also reviewed here. Meanwhile, future perspectives on polyamine research are also suggested. PMID:26528300

  3. Effects of heat stress on baroreflex function in humans

    NASA Technical Reports Server (NTRS)

    Crandall, Craig G.; Cui, Jian; Wilson, Thad E.

    2003-01-01

    INTRODUCTION: Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function. METHODS: In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non-pharmacological methods. In addition, the effects of heat stress on post-synaptic vasoconstrictor responsiveness were assessed. RESULTS: Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists. CONCLUSION: Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.

  4. Dynamic enhancement of autofocusing property for symmetric Airy beam with exponential amplitude modulation

    NASA Astrophysics Data System (ADS)

    Liu, Weiwei; Lu, Yao; Gong, Lei; Chu, Xiuxiang; Xue, Guosheng; Ren, Yuxuan; Zhong, Mincheng; Wang, Ziqiang; Zhou, Jinhua; Li, Yinmei

    2016-07-01

    A symmetric Airy beam (SAB) autofocuses during free space propagation. Such autofocusing SAB is useful in optical manipulation and biomedical imaging. However, its inherently limited autofocusing property may degrade the performance of the SAB in those applications. To enhance the autofocus, a symmetric apodization mask was proposed to regulate the SAB. In combination with the even cubic phase that shapes the SAB, this even exponential function mask with an adjustable parameter regulates the contribution of different frequency spectral components to the SAB. The propagation properties of this new amplitude modulated SAB (AMSAB) were investigated both theoretically and experimentally. Simulation shows that the energy distribution and autofocusing property of an AMSAB can be adjusted by the exponential amplitude modulation. Especially, the beam energy will be more concentrated in the central lobe once the even cubic phase is modulated by the mask with a higher proportion of high-frequency spectral components. Consequently, the autofocusing property and axial gradient force of AMSABs are efficiently enhanced. The experimental generation and characterization for AMSABs were implemented by modulating the collimated beam with a phase-only spatial light modulator. The experimental results well supported the theoretical predictions. With the ability to enhance the autofocus, the proposed exponential apodization modulation will make SAB more powerful in various applications, including optical trapping, fluorescence imaging and particle acceleration.

  5. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain

    NASA Astrophysics Data System (ADS)

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-02-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system.

  6. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain.

    PubMed

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-01-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795

  7. Lossless Airy Surface Polaritons in a Metamaterial via Active Raman Gain

    PubMed Central

    Zhang, Qi; Tan, Chaohua; Huang, Guoxiang

    2016-01-01

    We propose a scheme to realize a lossless propagation of linear and nonlinear Airy surface polaritons (SPs) via active Raman gain (ARG). The system we suggest is a planar interface superposed by a negative index metamaterial (NIMM) and a dielectric, where three-level quantum emitters are doped. By using the ARG from the quantum emitters and the destructive interference effect between the electric and magnetic responses from the NIMM, we show that not only the Ohmic loss of the NIMM but also the light absorption of the quantum emitters can be completely eliminated. As a result, non-diffractive Airy SPs may propagate for very long distance without attenuation. We also show that the Kerr nonlinearity of the system can be largely enhanced due to the introduction of the quantum emitters and hence lossless Airy surface polaritonic solitons with very low power can be generated in the system. PMID:26891795

  8. Cardiovascular function in the heat-stressed human.

    PubMed

    Crandall, C G; González-Alonso, J

    2010-08-01

    Heat stress, whether passive (i.e. exposure to elevated environmental temperatures) or via exercise, results in pronounced cardiovascular adjustments that are necessary for adequate temperature regulation as well as perfusion of the exercising muscle, heart and brain. The available data suggest that generally during passive heat stress baroreflex control of heart rate and sympathetic nerve activity are unchanged, while baroreflex control of systemic vascular resistance may be impaired perhaps due to attenuated vasoconstrictor responsiveness of the cutaneous circulation. Heat stress improves left ventricular systolic function, evidenced by increased cardiac contractility, thereby maintaining stroke volume despite large reductions in ventricular filling pressures. Heat stress-induced reductions in cerebral perfusion likely contribute to the recognized effect of this thermal condition in reducing orthostatic tolerance, although the mechanism(s) by which this occurs is not completely understood. The combination of intense whole-body exercise and environmental heat stress or dehydration-induced hyperthermia results in significant cardiovascular strain prior to exhaustion, which is characterized by reductions in cardiac output, stroke volume, arterial pressure and blood flow to the brain, skin and exercising muscle. These alterations in cardiovascular function and regulation late in heat stress/dehydration exercise might involve the interplay of both local and central reflexes, the contribution of which is presently unresolved. PMID:20345414

  9. Strehl-constrained reconstruction of post-adaptive optics data and the Software Package AIRY, v. 6.1

    NASA Astrophysics Data System (ADS)

    Carbillet, Marcel; La Camera, Andrea; Deguignet, Jérémy; Prato, Marco; Bertero, Mario; Aristidi, Éric; Boccacci, Patrizia

    2014-08-01

    We first briefly present the last version of the Software Package AIRY, version 6.1, a CAOS-based tool which includes various deconvolution methods, accelerations, regularizations, super-resolution, boundary effects reduction, point-spread function extraction/extrapolation, stopping rules, and constraints in the case of iterative blind deconvolution (IBD). Then, we focus on a new formulation of our Strehl-constrained IBD, here quantitatively compared to the original formulation for simulated near-infrared data of an 8-m class telescope equipped with adaptive optics (AO), showing their equivalence. Next, we extend the application of the original method to the visible domain with simulated data of an AO-equipped 1.5-m telescope, testing also the robustness of the method with respect to the Strehl ratio estimation.

  10. Arrays of Gaussian vortex, Bessel and Airy beams by computer-generated hologram

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Jiang, Bo; Lü, Shuchao; Liu, Yongqi; Li, Shasha; Cao, Zheng; Qi, Xinyuan

    2016-03-01

    We generate various kinds of arrays of Gaussian vortex, Bessel and Airy beams, respectively, with digital phase holograms (DPH) based on the fractional-Talbot effect by using the phase-only spatial light modulator (SLM). The linear and nonlinear transmissions of these beam arrays in strontium barium niobate (SBN) crystal are investigated numerically and experimentally. Compared with Gaussian vortex arrays, Bessel and Airy beam arrays can keep their patterns unchanged in over 20 mm, realizing non-diffracting transmission. The Fourier spectra (far-field diffraction patterns) of the lattices are also studied. The experimental results are in good agreement with the numerical simulations.

  11. Analysis of optical trapping and propulsion of Rayleigh particles using Airy beam.

    PubMed

    Cheng, Hua; Zang, Weiping; Zhou, Wenyuan; Tian, Jianguo

    2010-09-13

    The radiation forces and trajectories of Rayleigh dielectric particles induced by one-dimensional Airy beam were numerically analyzed. Results show that the Airy beam drags particles into the optical intensity peaks, and guides particles vertically along parabolic trajectories. Viscosity of surrounding medium significantly affects the trajectories. Random Brownian force affects the trajectories. Meanwhile, trapping potential depths and minimum trapping particle radii in different potential wells were also discussed. The trapping stability could be improved by increasing either the input peak intensity or the particle radius. PMID:20940930

  12. Learning Under Stress: The Inverted-U-Shape Function Revisited

    ERIC Educational Resources Information Center

    Salehi, Basira; Cordero, M. Isabel; Sandi, Carmen

    2010-01-01

    Although the relationship between stress intensity and memory function is generally believed to follow an inverted-U-shaped curve, strikingly this phenomenon has not been demonstrated under the same experimental conditions. We investigated this phenomenon for rats' performance in a hippocampus-dependent learning task, the radial arm water maze…

  13. Effect of coping on endocrinoimmune functions in different stress situations.

    PubMed

    Koh, Kyung Bong; Choe, Euiheon; Song, Jung Eun; Lee, Eun Ha

    2006-08-30

    The objective of this study was to examine the effects of coping strategies on the endocrine and immune functions in different stress situations. Thirty-eight medical students were enrolled in this study. Cell-mediated immune function was measured using the lymphocyte proliferative response to phytohemagglutinin (PHA) and interleukin-2 (IL-2) production during the nonexamination period and during the preexamination period. Endocrine functions were assessed by measuring the plasma levels of norepinephrine, adrenocorticotropic hormone (ACTH) and cortisol. The Global Assessment of Recent Stress (GARS) scale, the Stress Response Inventory, the anxiety, depression, and somatization subscales of the Symptom Checklist-90-revised, the Way of Coping-revised, the Toronto Alexithymia Scale and the Anger Expression Scale were used as psychometric measures. The subjects with higher levels of total GARS scores showed significantly higher IL-2 production during the nonexam period than those with lower levels of total GARS scores. During the same period, IL-2 production in the less positive reappraisal group was significantly higher than in the more positive reappraisal group. Lymphocyte proliferation in the group seeking less social support was also significantly higher than in the group seeking more social support. However, no significant association was found between the coping strategies and each of the hormone levels. These results suggest that positive reappraisal and seeking social support can be associated with the alteration of immune function during a chronic stress period. In particular, positive reappraisal is likely to reverse the stress-induced immune responses. This study did not find that neuroendocrine function such as the sympathetic-adrenal medullary axis or the hypothalamic-pituitary-adrenal axis is playing a mediating role in the relationship between coping and immunity. PMID:16831469

  14. Changes in ventricular function during emotional stress and cold exposure

    SciTech Connect

    Kiess, M.C.; Moore, R.A.; Dimsdale, J.; Alpert, N.M.; Boucher, C.A.; Strauss, H.W.

    1984-01-01

    Patients with cardiac disease frequently develop symptoms with emotional stress or cold exposure. To investigate the effects of these stresses in normal subjects, an ambulatory ventricular function monitor (VEST) (previously reported to measure EFs which correlate well with gamma camera measurements) was employed to record sequential 2 minute time activity curves from the left ventricles of 6 healthy men (ages 19-24) during a control period and during a 30 minute stress interview with a psychiatrist. Four of the subjects were also monitored in a cold room (1/sup 0/C) for 20 min. In addition to the left ventricular time-activity curve, heart rate (HR), and BP (cuff) were recorded. All subjects had increases in HR, BP and EF during the stress interview. Cold, however, produced decreases in HR and EF and an increase in BP. The results (mean +- SD) are tabulated. End-systolic and end-diastolic counts and hence volume decreased during the interview and increased during cold exposure. The results suggest that (1) ambulatory changes in ventricular function can be measured with the VEST, and (2) significant changes in cardiovascular physiology are seen in normal subjects during a stress interview and exposure to cold.

  15. Stress as a predictor of cognitive functioning in lupus.

    PubMed

    Peralta-Ramírez, M I; Coín-Mejías, M A; Jiménez-Alonso, J; Ortego-Centeno, N; Callejas-Rubio, J L; Caracuel-Romero, A; Pérez-García, M

    2006-01-01

    The objective of this study was to investigate the possible effects of the daily stress experienced during a six-month period on the cognitive functioning of patients with systemic lupus erythematosus (SLE). For this purpose, we evaluated the daily stress of 21 patients with lupus every day for six months. Later, we carried out a neuropsychological exam that included an evaluation of attention and memory. At the same time, scores on depression and anxiety were recorded with the objective of controlling other emotional variables that might be influencing these cognitive processes. The results show that daily stress was able to predict the scores on the neuropsychological variables studied. Specifically, the daily stress experienced in the previous six months is the variable with the greatest explanatory-predictive power on the scores for delayed recall visual memory, visual fluency and attention speed. This relationship proved to be negative in all three cases (R2 corr = 0.290; t = -2.712, P < 0.014); (R2 corr = 0.318; t = -2.818, P < 0.012); (R2 corr = 0.319; t = -2.906, P < 0.009), which means that the greater the daily stress, the lower the score on visual memory, fluency and total attention speed. We can state that daily stress is related to impairments in visual memory, fluency and attention in patients with SLE. This effect was not found with other emotional variables, such as depression and anxiety. PMID:17211991

  16. Wheat EST resources for functional genomics of abiotic stress

    PubMed Central

    Houde, Mario; Belcaid, Mahdi; Ouellet, François; Danyluk, Jean; Monroy, Antonio F; Dryanova, Ani; Gulick, Patrick; Bergeron, Anne; Laroche, André; Links, Matthew G; MacCarthy, Luke; Crosby, William L; Sarhan, Fathey

    2006-01-01

    Background Wheat is an excellent species to study freezing tolerance and other abiotic stresses. However, the sequence of the wheat genome has not been completely characterized due to its complexity and large size. To circumvent this obstacle and identify genes involved in cold acclimation and associated stresses, a large scale EST sequencing approach was undertaken by the Functional Genomics of Abiotic Stress (FGAS) project. Results We generated 73,521 quality-filtered ESTs from eleven cDNA libraries constructed from wheat plants exposed to various abiotic stresses and at different developmental stages. In addition, 196,041 ESTs for which tracefiles were available from the National Science Foundation wheat EST sequencing program and DuPont were also quality-filtered and used in the analysis. Clustering of the combined ESTs with d2_cluster and TGICL yielded a few large clusters containing several thousand ESTs that were refractory to routine clustering techniques. To resolve this problem, the sequence proximity and "bridges" were identified by an e-value distance graph to manually break clusters into smaller groups. Assembly of the resolved ESTs generated a 75,488 unique sequence set (31,580 contigs and 43,908 singletons/singlets). Digital expression analyses indicated that the FGAS dataset is enriched in stress-regulated genes compared to the other public datasets. Over 43% of the unique sequence set was annotated and classified into functional categories according to Gene Ontology. Conclusion We have annotated 29,556 different sequences, an almost 5-fold increase in annotated sequences compared to the available wheat public databases. Digital expression analysis combined with gene annotation helped in the identification of several pathways associated with abiotic stress. The genomic resources and knowledge developed by this project will contribute to a better understanding of the different mechanisms that govern stress tolerance in wheat and other cereals. PMID

  17. Per capita interactions and stress tolerance drive stress-induced changes in biodiversity effects on ecosystem functions.

    PubMed

    Baert, Jan M; Janssen, Colin R; Sabbe, Koen; De Laender, Frederik

    2016-01-01

    Environmental stress changes the relationship between biodiversity and ecosystem functions, but the underlying mechanisms are poorly understood. Because species interactions shape biodiversity-ecosystem functioning relationships, changes in per capita interactions under stress (as predicted by the stress gradient hypothesis) can be an important driver of stress-induced changes in these relationships. To test this hypothesis, we measure productivity in microalgae communities along a diversity and herbicide gradient. On the basis of additive partitioning and a mechanistic community model, we demonstrate that changes in per capita interactions do not explain effects of herbicide stress on the biodiversity-productivity relationship. Instead, assuming that the per capita interactions remain unaffected by stress, causing species densities to only change through differences in stress tolerance, suffices to predict the stress-induced changes in the biodiversity-productivity relationship and community composition. We discuss how our findings set the stage for developing theory on how environmental stress changes biodiversity effects on ecosystem functions. PMID:27534986

  18. Per capita interactions and stress tolerance drive stress-induced changes in biodiversity effects on ecosystem functions

    PubMed Central

    Baert, Jan M.; Janssen, Colin R.; Sabbe, Koen; De Laender, Frederik

    2016-01-01

    Environmental stress changes the relationship between biodiversity and ecosystem functions, but the underlying mechanisms are poorly understood. Because species interactions shape biodiversity–ecosystem functioning relationships, changes in per capita interactions under stress (as predicted by the stress gradient hypothesis) can be an important driver of stress-induced changes in these relationships. To test this hypothesis, we measure productivity in microalgae communities along a diversity and herbicide gradient. On the basis of additive partitioning and a mechanistic community model, we demonstrate that changes in per capita interactions do not explain effects of herbicide stress on the biodiversity–productivity relationship. Instead, assuming that the per capita interactions remain unaffected by stress, causing species densities to only change through differences in stress tolerance, suffices to predict the stress-induced changes in the biodiversity–productivity relationship and community composition. We discuss how our findings set the stage for developing theory on how environmental stress changes biodiversity effects on ecosystem functions. PMID:27534986

  19. Resistance of functional Lactobacillus plantarum strains against food stress conditions.

    PubMed

    Ferrando, Verónica; Quiberoni, Andrea; Reinhemer, Jorge; Suárez, Viviana

    2015-06-01

    The survival of three Lactobacillus plantarum strains (Lp 790, Lp 813 and Lp 998) with functional properties was studied taking into account their resistance to thermal, osmotic and oxidative stress factors. Stress treatments applied were: 52 °C-15 min (Phosphate Buffer pH 7, thermal shock), H2O2 0.1% (p/v) - 30 min (oxidative shock) and NaCl aqueous solution at 17, 25 and 30% (p/v) (room temperature - 1 h, osmotic shock). The osmotic stress was also evaluated on cell growth in MRS broth added of 2, 4, 6, 8 and 10% (p/v) of NaCl, during 20 h at 30 °C. The cell thermal adaptation was performed in MRS broth, selecting 45 °C for 30 min as final conditions for all strains. Two strains (Lp 813 and Lp 998) showed, in general, similar behaviour against the three stress factors, being clearly more resistant than Lp 790. An evident difference in growth kinetics in presence of NaCl was observed between Lp 998 and Lp 813, Lp998 showing a higher optical density (OD570nm) than Lp 813 at the end of the assay. Selected thermal adaptation improved by 2 log orders the thermal resistance of both strains, but cell growth in presence of NaCl was enhanced only in Lp 813. Oxidative resistance was not affected with this thermal pre-treatment. These results demonstrate the relevance of cell technological resistance when selecting presumptive "probiotic" cultures, since different stress factors might considerably affect viability or/and performance of the strains. The incidence of stress conditions on functional properties of the strains used in this work are currently under research in our group. PMID:25790993

  20. Fluid shear stress modulation of hepatocyte-like cell function.

    PubMed

    Rashidi, Hassan; Alhaque, Sharmin; Szkolnicka, Dagmara; Flint, Oliver; Hay, David C

    2016-07-01

    Freshly isolated human adult hepatocytes are considered to be the gold standard tool for in vitro studies. However, primary hepatocyte scarcity, cell cycle arrest and the rapid loss of cell phenotype limit their widespread deployment. Human embryonic stem cells and induced pluripotent stem cells provide renewable sources of hepatocyte-like cells (HLCs). Despite the use of various differentiation methodologies, HLCs like primary human hepatocytes exhibit unstable phenotype in culture. It has been shown that the functional capacity can be improved by adding back elements of human physiology, such as cell co-culture or through the use of natural and/or synthetic surfaces. In this study, the effect of fluid shear stress on HLC performance was investigated. We studied two important liver functions, cytochrome P450 drug metabolism and serum protein secretion, in static cultures and those exposed to fluid shear stress. Our study demonstrates that fluid shear stress improved Cyp1A2 activity by approximately fivefold. This was paralleled by an approximate ninefold increase in sensitivity to a drug, primarily metabolised by Cyp2D6. In addition to metabolic capacity, fluid shear stress also improved hepatocyte phenotype with an approximate fourfold reduction in the secretion of a foetal marker, alpha-fetoprotein. We believe these studies highlight the importance of introducing physiologic cues in cell-based models to improve somatic cell phenotype. PMID:26979076

  1. Anomalous change of Airy disk with changing size of spherical particles

    NASA Astrophysics Data System (ADS)

    Pan, Linchao; Zhang, Fugen; Meng, Rui; Xu, Jie; Zuo, Chenze; Ge, Baozhen

    2016-02-01

    Use of laser diffraction is considered as a method of reliable principle and mature technique in measurements of particle size distributions. It is generally accepted that for a certain relative refractive index, the size of the scattering pattern (also called Airy disk) of spherical particles monotonically decreases with increasing particle size. This fine structure forms the foundation of the laser diffraction method. Here we show that the Airy disk size of non-absorbing spherical particles becomes larger with increasing particle size in certain size ranges. To learn more about this anomalous change of Airy disk (ACAD), we present images of Airy disk and curves of Airy disk size versus particle size for spherical particles of different relative refractive indices by using Mie theory. These figures reveal that ACAD occurs periodically for non-absorbing particles and will disappear when the absorbing efficiency is higher than certain value. Then by using geometrical optics (GO) approximation, we derive the analytical formulae for the bounds of the size ranges where ACAD occurs. From the formulae, we obtain laws of ACAD as follows: (1) for non-absorbing particles, ACAD occurs periodically, and when the particle size tends to infinity, the period tends to a certain value. As the relative refractive index increases, (2) the particle size ranges where ACAD occurs shift to smaller values, (3) the period of ACAD becomes smaller, and (4) the width of the size ranges where ACAD occurs becomes narrower. In addition, we can predict from the formulae that ACAD also exists for particles whose relative refractive index is smaller than 1.

  2. Functional neuroimaging studies of post-traumatic stress disorder

    PubMed Central

    Hughes, Katherine C; Shin, Lisa M

    2011-01-01

    Post-traumatic stress disorder (PTSD) is a significant problem that can affect individuals who have been exposed to a traumatic event or events, such as combat, violent crime or childhood abuse. Over the past several years, neuroimaging studies of PTSD have focused on elucidating the brain circuits that mediate this disorder. In this article, we will briefly introduce some of the methods used in functional neuroimaging studies of PTSD. We will then review functional neuroimaging studies that have reported significant findings in the amygdala, medial prefrontal cortex, hippocampus and insula. Finally, we will suggest future directions for research. PMID:21306214

  3. Stress physiology functions of the Arabidopsis histidine kinase cytokinin receptors.

    PubMed

    Kumar, M Nagaraj; Verslues, Paul E

    2015-07-01

    Cytokinin signaling has complex effects on abiotic stress responses that remain to be fully elucidated. The Arabidopsis histidine kinases (AHKs), AHK2, AHK3 and CRE1 (cytokinin response1/AHK4) are the principle cytokinin receptors of Arabidopsis. Using a set of ahk mutants, we found dramatic differences in response to low water potential and salt stress among the AHKs. ahk3-3 mutants had increased root elongation after transfer to low water potential media. Conversely ahk2-2 was hypersensitive to salt stress in terms of root growth and fresh weight and accumulated higher than wild-type levels of proline specifically under salt stress. Strongly reduced proline accumulation in ahk double mutants after low water potential treatment indicated a more general role of cytokinin signaling in proline metabolism. Reduced P5CS1 (Δ(1) -pyrroline-5-carboxylate synthetase1) gene expression may have contributed to this reduced proline accumulation. Low water potential phenotypes of ahk mutants were not caused by altered abscisic acid (ABA) accumulation as all ahk mutants had wild-type ABA levels, despite the observation that ahk double mutants had reduced NCED3 (9-cis-epoxycartenoid dioxygenase3) expression when exposed to low water potential. No difference in osmoregulatory solute accumulation was detected in any of the ahk mutants indicating that they do not affect drought responsive osmotic adjustment. Overall, our examination of ahk mutants found specific phenotypes associated with AHK2 and AHK3 as well as a general function of cytokinin signaling in proline accumulation and low water potential induction of P5CS1 and NCED3 expression. These results show the stress physiology function of AHKs at a new level of detail. PMID:25263537

  4. Attentional networks reveal executive function deficits in posttraumatic stress disorder.

    PubMed

    Leskin, Lorraine P; White, Patricia M

    2007-05-01

    Executive function was assessed with the Trail Making Test (Army Individual Test Battery; M. D. Lezak, 1983), the Comprehensive Trail Making Test (C. Reynolds, 2002), and a neurocognitive measure of executive control (Attentional Network Task [ANT]; J. I. Fan, B. D. McCandliss, T. Somer, A. Raz, & M. I. Posner, 2002) in 19 undergraduates with posttraumatic stress disorder (PTSD; Posttraumatic Stress Disorder Symptom Scale-Self-Report version; E. B. Foa, D. S. Riggs, C. V. Dancu, & B. O. Rothbaum, 1993), 15 high trauma participants without PTSD, and 18 low trauma control participants. Although groups did not differ on any trail making task or on the ANT measures of alerting or orienting, PTSD participants were significantly more impaired on the ANT executive network index than were high or low trauma control participants, even when level of depressive symptoms was covaried. Previous animal research identified a relationship between dopamine and the ANT measure of executive function. Elevated PTSD symptom severity and levels of hyperarousal, reexperiencing, and avoidance-numbing were associated significantly with executive function deficits indexed by the ANT. These results indicate a potentially subtle but specific deficit in executive function and a possible relationship between PTSD symptoms and irregularities in dopamine function. PMID:17484590

  5. A micromechanical study of residual stresses in functionally graded materials

    SciTech Connect

    Dao, M.; Gu, P.; Maewal, A.; Asaro, R.J.

    1997-08-01

    A physically based computational micromechanics model is developed to study random and discrete microstructures in functionally graded materials (FGMs). The influences of discrete microstructure on residual stress distributions at grain size level are examined with respect to material gradient and FGM volume percentage (within a ceramic-FGM-metal three-layer structure). Both thermoelastic and thermoplastic deformation are considered, and the plastic behavior of metal grains is modeled at the single crystal level using crystal plasticity theory. The results are compared with those obtained using a continuous model which does not consider the microstructural randomness and discreteness. In an averaged sense both the micromechanics model and the continuous model give practically the same macroscopic stresses; whereas the discrete micromechanics model predicts fairly high residual stress concentrations at the grain size level (i.e., higher than 700 MPa in 5--6 vol% FGM grains) with only a 300 C temperature drop in a Ni-Al{sub 2}O{sub 3} FGM system. Statistical analysis shows that the residual stress concentrations are insensitive to material gradient and FGM volume percentage. The need to consider microstructural details in FGM microstructures is evident. The results obtained provide some insights for improving the reliability of FGMs against fracture and delamination.

  6. Structural and functional evolution of vertebrate neuroendocrine stress systems.

    PubMed

    Denver, Robert John

    2009-04-01

    The vertebrate hypothalamus-pituitary-adrenal (HPA; or interrenal) axis plays pivotal roles in animal development and in physiological and behavioral adaptation to environmental change. The HPA, or stress axis, is organized in a hierarchical manner, with feedback operating at several points along the axis. Recent findings suggest that the proteins, gene structures, and signaling pathways of the HPA axis were present in the earliest vertebrates and have been maintained by natural selection owing to their critical adaptive roles. In all vertebrates studied, the HPA axis is activated in response to stressors and is controlled centrally by peptides of the corticotropin-releasing factor (CRF) family of which four paralogous members have been identified. Signaling by CRF-like peptides is mediated by at least two distinct G protein-coupled receptors and modulated by a secreted binding protein. These neuropeptides function as hypophysiotropins and as neurotransmitters/neuromodulators, influencing stress-related behaviors, such as anxiety and fear. In addition to modulating HPA activity and behavioral stress responses, CRF-like peptides are implicated in timing key life history transitions, such as metamorphosis in amphibians and birth in mammals. CRF-like peptides and signaling components are also expressed outside of the central nervous system where they have diverse physiological functions. Glucocorticoids are the downstream effectors of the HPA axis, playing essential roles in development, energy balance and behavior, and feedback actions on the activity of the HPA axis. PMID:19456324

  7. Combined thermal and herbicide stress in functionally diverse coral symbionts.

    PubMed

    van Dam, J W; Uthicke, S; Beltran, V H; Mueller, J F; Negri, A P

    2015-09-01

    Most reef building corals rely on symbiotic microalgae (genus Symbiodinium) to supply a substantial proportion of their energy requirements. Functional diversity of different Symbiodinium genotypes, endorsing the host with physiological advantages, has been widely reported. Yet, the influence of genotypic specificity on the symbiont's susceptibility to contaminants or cumulative stressors is unknown. Cultured Symbiodinium of presumed thermal-tolerant clade D tested especially vulnerable to the widespread herbicide diuron, suggesting important free-living populations may be at risk in areas subjected to terrestrial runoff. Co-exposure experiments where cultured Symbiodinium were exposed to diuron over a thermal stress gradient demonstrated how fast-growing clade C1 better maintained photosynthetic capability than clade D. The mixture toxicity model of Independent Action, considering combined thermal stress and herbicide contamination, revealed response additivity for inhibition of photosynthetic yield in both tested cultures, emphasizing the need to account for cumulative stressor impacts in ecological risk assessment and resource management. PMID:25989453

  8. Neuropsychological functioning in children with posttraumatic stress disorder.

    PubMed

    Samuelson, Kristin W; Krueger, Casey E; Burnett, Christiane; Wilson, Christina K

    2010-01-01

    Posttraumatic stress disorder (PTSD) has been associated with deficits in the areas of verbal memory and learning, executive functioning, working memory, and attention in adults. Findings have been less consistent in the few studies examining neuropsychological functioning in childhood PTSD, which are often limited by comparing children with PTSD to children without trauma histories, making it unclear whether observed neuropsychological deficits are related to trauma exposure or to PTSD symptomatology. In an ethnically diverse sample of 62 children who witnessed intimate partner violence (n = 27 PTSD+ and 35 PTSD-), children with PTSD exhibited slower and less effective learning, heightened sensitivity to interference, and impaired effect of rehearsal on memory acquisition on the California Verbal Learning Test - Children's Version, a word list learning task. Both groups performed in the below average range on measures of executive functioning, attention, and intellectual ability. PMID:19787496

  9. Analytical Model for Thermal Elastoplastic Stresses of Functionally Graded Materials

    SciTech Connect

    Zhai, P. C.; Chen, G.; Liu, L. S.; Fang, C.; Zhang, Q. J.

    2008-02-15

    A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. Shen and S. Suresh [6]. In the present model, the functionally graded materials are considered as multilayered materials. Each layer consists of metal and ceramic with different volume fraction. The ceramic layer and the FGM interlayers are considered as elastic brittle materials. The metal layer is considered as elastic-perfectly plastic ductile materials. Closed-form solutions for different characteristic temperature for thermal loading are presented as a function of the structure geometries and the thermomechanical properties of the materials. A main advance of the present model is that the possibility of the initial and spread of plasticity from the two sides of the ductile layers taken into account. Comparing the analytical results with the results from the finite element analysis, the thermal stresses and deformation from the present model are in good agreement with the numerical ones.

  10. A compact Airy beam light sheet microscope with a tilted cylindrical lens.

    PubMed

    Yang, Zhengyi; Prokopas, Martynas; Nylk, Jonathan; Coll-Lladó, Clara; Gunn-Moore, Frank J; Ferrier, David E K; Vettenburg, Tom; Dholakia, Kishan

    2014-10-01

    Light-sheet imaging is rapidly gaining importance for imaging intact biological specimens. Many of the latest innovations rely on the propagation-invariant Bessel or Airy beams to form an extended light sheet to provide high resolution across a large field of view. Shaping light to realize propagation-invariant beams often relies on complex programming of spatial light modulators or specialized, custom made, optical elements. Here we present a straightforward and low-cost modification to the traditional light-sheet setup, based on the open-access light-sheet microscope OpenSPIM, to achieve Airy light-sheet illumination. This brings wide field single-photon light-sheet imaging to a broader range of endusers. Fluorescent microspheres embedded in agarose and a zebrafish larva were imaged to demonstrate how such a microscope can have a minimal footprint and cost without compromising on imaging quality. PMID:25360362

  11. Wavelength estimation by using the Airy disk from a diffraction pattern with didactic purposes

    NASA Astrophysics Data System (ADS)

    Rivera-Ortega, Uriel; Pico-Gonzalez, Beatriz

    2016-01-01

    In this paper a simple and easy to implement method that uses the Airy disk generated from a Fraunhofer diffraction pattern due to a circular aperture will be used to estimate the wavelength of the illuminating laser source. This estimation is based on the measurement of the Airy disk diameter, whose approximation is directly proportional to the wavelength of the light source and to the distance between the aperture and the image plane; and inversely proportional to the diameter of the aperture. Due to the characteristics and versatility of the present proposal, this is perfectly suitable for use in graduate or undergraduate physics laboratories, or even in classrooms for educational and/or demonstrative purposes.

  12. A compact Airy beam light sheet microscope with a tilted cylindrical lens

    PubMed Central

    Yang, Zhengyi; Prokopas, Martynas; Nylk, Jonathan; Coll-Lladó, Clara; Gunn-Moore, Frank J.; Ferrier, David E. K.; Vettenburg, Tom; Dholakia, Kishan

    2014-01-01

    Light-sheet imaging is rapidly gaining importance for imaging intact biological specimens. Many of the latest innovations rely on the propagation-invariant Bessel or Airy beams to form an extended light sheet to provide high resolution across a large field of view. Shaping light to realize propagation-invariant beams often relies on complex programming of spatial light modulators or specialized, custom made, optical elements. Here we present a straightforward and low-cost modification to the traditional light-sheet setup, based on the open-access light-sheet microscope OpenSPIM, to achieve Airy light-sheet illumination. This brings wide field single-photon light-sheet imaging to a broader range of endusers. Fluorescent microspheres embedded in agarose and a zebrafish larva were imaged to demonstrate how such a microscope can have a minimal footprint and cost without compromising on imaging quality. PMID:25360362

  13. Nonlinear dynamics of Airy-vortex 3D wave packets: emission of vortex light waves.

    PubMed

    Driben, Rodislav; Meier, Torsten

    2014-10-01

    The dynamics of 3D Airy-vortex wave packets is studied under the action of strong self-focusing Kerr nonlinearity. Emissions of nonlinear 3D waves out of the main wave packets with the topological charges were demonstrated. Because of the conservation of the total angular momentum, charges of the emitted waves are equal to those carried by the parental light structure. The rapid collapse imposes a severe limitation on the propagation of multidimensional waves in Kerr media. However, the structure of the Airy beam carrier allows the coupling of light from the leading, most intense peak into neighboring peaks and consequently strongly postpones the collapse. The dependence of the critical input amplitude for the appearance of a fast collapse on the beam width is studied for wave packets with zero and nonzero topological charges. Wave packets carrying angular momentum are found to be much more resistant to the rapid collapse. PMID:25360922

  14. Function of a hearing aid under stressful conditions.

    PubMed

    Welsh, L W; Welsh, J J; Rosen, L F

    2000-10-01

    The auditory function of individuals with normal hearing was compared with that of hearing-aided subjects of similar age to determine whether amplification remediates hearing impairment under stressful auditory situations. The specific tests of listening in a competitive noise environment and identifying moderately compressed speech were introduced to adequately aided individuals. The data indicate that noise had an impact on auditory function to a much greater degree in aided individuals than in matched counterparts with normal hearing. The data derived from acceleration of simple sentences delivered to the aided group suggested that contrary to basic tonal sensitivity, the capacity to understand the stimulus was greatly compromised. The authors discuss cochlear damage and central auditory impairment as they relate to the limitations of amplification for sensorineural hearing loss. PMID:11051433

  15. Dr. Airy's "morbid affection of the eyesight": lessons from Teichopsia Circa 1870.

    PubMed

    Lepore, Frederick E

    2014-09-01

    Hubert Airy's iconic drawing of his own migraine visual aura for which he coined the term, "teichopsia," conveys important lessons for the contemporary clinician. His observations of the expansion ("build-up"), minification/magnification, and color/achromatopsia of migrainous teichopsia are consistent with (and possibly anticipatory of) the later discoveries of cortical spreading depression, cortical magnification of primary visual cortex (V1), and specialized cortical centers for color vision. PMID:24840023

  16. Can Hooke's Law and the Airy Disk First Zero Radius Formulation Predict That Education and Work Environment Visual Task Excesses Lead to Vision Impairment?

    NASA Astrophysics Data System (ADS)

    McLeod, Douglas M.; McLeod, Roger D.

    2002-10-01

    DMM found that a distant, single church steeple, which appeared "twin-like" after extended studying episodes, could then be brought into correct visual register by a conscious effort. Similar anecdotal events are repeatable by attentive students or workers in the early stages of educationally or work environmentally induced repetitive vision impairment. RDM proposes that his model for vision and its repair utilizes sequentially applied vision improvement stages that are the equivalent of DMM's experience. Such visual events involve feedback signals generated during the crystalline lens's minor dioptric oscillations that are generated by the blinking reflex, empowered by the Airy radius proportional to wavelength times focal length divided by pupil aperture. This implies some conscious control of feedback mechanisms, which can self-regulate vision protecting processes. Continued visual effort under duress invokes Hooke's "stress proportional to strain." Exceeding extrinsic eye muscles' elastic limits overrides spontaneous feedback repair mechanisms.

  17. Shaping symmetric Airy beam through binary amplitude modulation for ultralong needle focus

    SciTech Connect

    Fang, Zhao-Xiang; Gong, Lei; Ren, Yu-Xuan; Vaveliuk, Pablo; Chen, Yue; Lu, Rong-De

    2015-11-28

    Needle-like electromagnetic field has various advantages for the applications in high-resolution imaging, Raman spectroscopy, as well as long-distance optical transportation. The realization of such field often requires high numerical aperture (NA) objective lens and the transmission masks. We demonstrate an ultralong needle-like focus in the optical range produced with an ordinary lens. This is achieved by focusing a symmetric Airy beam (SAB) generated via binary spectral modulation with a digital micromirror device. Such amplitude modulation technique is able to shape traditional Airy beams, SABs, as well as the dynamic transition modes between the one-dimensional and two-dimensional (2D) symmetric Airy modes. The created 2D SAB was characterized through measurement of the propagating fields with one of the four main lobes blocked by an opaque mask. The 2D SAB was verified to exhibit self-healing property against propagation with the obstructed major lobe reconstructed after a certain distance. We further produced an elongated focal line by concentrating the SAB via lenses with different NAs and achieved an ultralong longitudinal needle focus. The produced long needle focus will be applied in optical, chemical, and biological sciences.

  18. Shear-stress relaxation and ensemble transformation of shear-stress autocorrelation functions.

    PubMed

    Wittmer, J P; Xu, H; Baschnagel, J

    2015-02-01

    We revisit the relation between the shear-stress relaxation modulus G(t), computed at finite shear strain 0<γ≪1, and the shear-stress autocorrelation functions C(t)|(γ) and C(t)|(τ) computed, respectively, at imposed strain γ and mean stress τ. Focusing on permanent isotropic spring networks it is shown theoretically and computationally that in general G(t)=C(t)|(τ)=C(t)|(γ)+G(eq) for t>0 with G(eq) being the static equilibrium shear modulus. G(t) and C(t)|(γ) thus must become different for solids and it is impossible to obtain G(eq) alone from C(t)|(γ) as often assumed. We comment briefly on self-assembled transient networks where G(eq)(f) must vanish for a finite scission-recombination frequency f. We argue that G(t)=C(t)|(τ)=C(t)|(γ) should reveal an intermediate plateau set by the shear modulus G(eq)(f=0) of the quenched network. PMID:25768458

  19. Abnormal Functional Connectivity Density in Post-traumatic Stress Disorder.

    PubMed

    Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Liu, Feng; Chen, Huafu

    2016-05-01

    Post-traumatic stress disorder (PTSD) is a psychiatric disorder that occurs in individuals who have experienced life-threatening mental traumas. Previous neuroimaging studies have indicated that the pathology of PTSD may be associated with the abnormal functional integration among brain regions. In the current study, we used functional connectivity density (FCD) mapping, a novel voxel-wise data-driven approach based on graph theory, to explore aberrant FC through the resting-state functional magnetic resonance imaging of the PTSD. We calculated both short- and long-range FCD in PTSD patients and healthy controls (HCs). Compared with HCs, PTSD patients showed significantly increased long-range FCD in the left dorsolateral prefrontal cortex (DLPFC), but no abnormal short-range FCD was found in PTSD. Furthermore, seed-based FC analysis of the left DLPFC showed increased connectivity in the left superior parietal lobe and visual cortex of PTSD patients. The results suggested that PTSD patients experienced a disruption of intrinsic long-range functional connections in the fronto-parietal network and visual cortex, which are associated with attention control and visual information processing. PMID:26830769

  20. Epigenetic and immune function profiles associated with posttraumatic stress disorder

    PubMed Central

    Uddin, Monica; Aiello, Allison E.; Wildman, Derek E.; Koenen, Karestan C.; Pawelec, Graham; de los Santos, Regina; Goldmann, Emily; Galea, Sandro

    2010-01-01

    The biologic underpinnings of posttraumatic stress disorder (PTSD) have not been fully elucidated. Previous work suggests that alterations in the immune system are characteristic of the disorder. Identifying the biologic mechanisms by which such alterations occur could provide fundamental insights into the etiology and treatment of PTSD. Here we identify specific epigenetic profiles underlying immune system changes associated with PTSD. Using blood samples (n = 100) obtained from an ongoing, prospective epidemiologic study in Detroit, the Detroit Neighborhood Health Study, we applied methylation microarrays to assay CpG sites from more than 14,000 genes among 23 PTSD-affected and 77 PTSD-unaffected individuals. We show that immune system functions are significantly overrepresented among the annotations associated with genes uniquely unmethylated among those with PTSD. We further demonstrate that genes whose methylation levels are significantly and negatively correlated with traumatic burden show a similar strong signal of immune function among the PTSD affected. The observed epigenetic variability in immune function by PTSD is corroborated using an independent biologic marker of immune response to infection, CMV—a typically latent herpesvirus whose activity was significantly higher among those with PTSD. This report of peripheral epigenomic and CMV profiles associated with mental illness suggests a biologic model of PTSD etiology in which an externally experienced traumatic event induces downstream alterations in immune function by reducing methylation levels of immune-related genes. PMID:20439746

  1. Anxiety, stress, depression, and psychosocial functioning of Indian adolescents

    PubMed Central

    Singh, Kamlesh; Junnarkar, Mohita; Sharma, Soumya

    2015-01-01

    Background: Lifetime prevalence of depression and anxiety increases from 1% of the population under age 12 years to ~17%-25% of the population by the end of adolescence. The greatest increase in new cases occurs between 15-18 years. Indian empirical studies have reported a prevalence of psychiatric morbidity in the range between 14.4% and 31.7%; thus, affecting psychosocial functioning. Aims: The objectives of the current study were to (i) examine the psychometric properties of the DASS and SDQ on Indian adolescents, (ii) explore the role of socio- demographic variablesand (iii) examine if there was any difference between school going and school dropouts. Methodology: Data from 1812 students, aged 12-19 years was collected with mean age = 15.67 years (SD =1.41 years). The participants were administered a booklet containing demographic questionnaire and psychometric scales such as DASS-21 (Henry & Crawford, 2005; Lovibond & Lovibond, 1999) and Strengths and Difficulties Questionnaire (Goodman, 1997). Statistical Analysis: Structure validation, correlational analysis and multivariate analysis. Results and Conclusions: The results of validation indicated that English and Hindi version of 3 factor model of DASS and 2 factor model of SDQ was an acceptable model fit. It was noted that early adolescents were high on prosocial behaviour whereas late adolescents were high on difficulties score. Females were higher than males on prosocial behaviour. Adolescents residing in rural areas differed from their urban counterparts on prosocial behaviour and anxiety. Government school going adolescents differed from private school going adolescents on prosocial behaviour, stress and anxiety. Negative perception of relationship with family affected adolescents difficulties score, depression and stress. Similarly, negative perception of self-concept leads to higher difficulties score and lower prosocial behaviour score. The school going adolescents differed from non-school going

  2. Structural and functional insight into the universal stress protein family

    PubMed Central

    Tkaczuk, Karolina L; A Shumilin, Igor; Chruszcz, Maksymilian; Evdokimova, Elena; Savchenko, Alexei; Minor, Wladek

    2013-01-01

    We present the crystal structures of two universal stress proteins (USP) from Archaeoglobus fulgidus and Nitrosomonas europaea in both apo- and ligand-bound forms. This work is the first complete synthesis of the structural properties of 26 USP available in the Protein Data Bank, over 75% of which were determined by structure genomics centers with no additional information provided. The results of bioinformatic analyses of all available USP structures and their sequence homologs revealed that these two new USP structures share overall structural similarity with structures of USPs previously determined. Clustering and cladogram analyses, however, show how they diverge from other members of the USP superfamily and show greater similarity to USPs from organisms inhabiting extreme environments. We compared them with other archaeal and bacterial USPs and discuss their similarities and differences in context of structure, sequential motifs, and potential function. We also attempted to group all analyzed USPs into families, so that assignment of the potential function to those with no experimental data available would be possible by extrapolation. PMID:23745136

  3. Diabetes and mitochondrial function: Role of hyperglycemia and oxidative stress

    SciTech Connect

    Rolo, Anabela P.; Palmeira, Carlos M. . E-mail: palmeira@ci.uc.pt

    2006-04-15

    Hyperglycemia resulting from uncontrolled glucose regulation is widely recognized as the causal link between diabetes and diabetic complications. Four major molecular mechanisms have been implicated in hyperglycemia-induced tissue damage: activation of protein kinase C (PKC) isoforms via de novo synthesis of the lipid second messenger diacylglycerol (DAG), increased hexosamine pathway flux, increased advanced glycation end product (AGE) formation, and increased polyol pathway flux. Hyperglycemia-induced overproduction of superoxide is the causal link between high glucose and the pathways responsible for hyperglycemic damage. In fact, diabetes is typically accompanied by increased production of free radicals and/or impaired antioxidant defense capabilities, indicating a central contribution for reactive oxygen species (ROS) in the onset, progression, and pathological consequences of diabetes. Besides oxidative stress, a growing body of evidence has demonstrated a link between various disturbances in mitochondrial functioning and type 2 diabetes. Mutations in mitochondrial DNA (mtDNA) and decreases in mtDNA copy number have been linked to the pathogenesis of type 2 diabetes. The study of the relationship of mtDNA to type 2 diabetes has revealed the influence of the mitochondria on nuclear-encoded glucose transporters, glucose-stimulated insulin secretion, and nuclear-encoded uncoupling proteins (UCPs) in {beta}-cell glucose toxicity. This review focuses on a range of mitochondrial factors important in the pathogenesis of diabetes. We review the published literature regarding the direct effects of hyperglycemia on mitochondrial function and suggest the possibility of regulation of mitochondrial function at a transcriptional level in response to hyperglycemia. The main goal of this review is to include a fresh consideration of pathways involved in hyperglycemia-induced diabetic complications.

  4. Coherent mid-infrared supercontinuum generation with As2Se3 photonic crystal fiber and femtosecond Airy pulses

    NASA Astrophysics Data System (ADS)

    Yuan, Wu

    2015-12-01

    We discuss a novel method for generating hyper-broadband mid-infrared (MIR) supercontinua (SC) with coherent bandwidth from ~2 μm to ~10 μm by using As2Se3 photonic crystal fiber (PCF) and a 4.1 μm pump with femtosecond (fs) Airy pulse profile. Our simulations confirm that, when pumping in the normal dispersion region, the deceleration and self-healing properties of the Airy pulse can suppress the incoherent noise in modulational instability (MI) induced SC generation and maintain the pulse coherence over a long propagation distance. We also find that fs Airy pulse can generate an MIR SC with a broader coherent bandwidth than these can be achieved with fs parabolic secant pulse.

  5. Improvement in cerebral function with treatment of posttraumatic stress disorder.

    PubMed

    Roy, Michael J; Francis, Jennifer; Friedlander, Joshua; Banks-Williams, Lisa; Lande, Raymond G; Taylor, Patricia; Blair, James; McLellan, Jennifer; Law, Wendy; Tarpley, Vanita; Patt, Ivy; Yu, Henry; Mallinger, Alan; Difede, Joann; Rizzo, Albert; Rothbaum, Barbara

    2010-10-01

    Posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) are signature illnesses of the Iraq and Afghanistan wars, but current diagnostic and therapeutic measures for these conditions are suboptimal. In our study, functional magnetic resonance imaging (fMRI) is used to try to differentiate military service members with: PTSD and mTBI, PTSD alone, mTBI alone, and neither PTSD nor mTBI. Those with PTSD are then randomized to virtual reality exposure therapy or imaginal exposure. fMRI is repeated after treatment and along with the Clinician-Administered PTSD Scale (CAPS) and Clinical Global Impression (CGI) scores to compare with baseline. Twenty subjects have completed baseline fMRI scans, including four controls and one mTBI only; of 15 treated for PTSD, eight completed posttreatment scans. Most subjects have been male (93%) and Caucasian (83%), with a mean age of 34. Significant improvements are evident on fMRI scans, and corroborated by CGI scores, but CAPS scores improvements are modest. In conclusion, CGI scores and fMRI scans indicate significant improvement in PTSD in both treatment arms, though CAPS score improvements are less robust. PMID:20955336

  6. Functional network topology associated with posttraumatic stress disorder in veterans

    PubMed Central

    Kennis, M.; van Rooij, S.J.H.; van den Heuvel, M.P.; Kahn, R.S.; Geuze, E.

    2015-01-01

    Posttraumatic stress disorder (PTSD) is a disabling disorder associated with resting state functional connectivity alterations. However, whether specific brain regions are altered in PTSD or whether the whole brain network organization differs remains unclear. PTSD can be treated with trauma-focused therapy, although only half of the patients recover after treatment. In order to better understand PTSD psychopathology our aim was to study resting state networks in PTSD before and after treatment. Resting state functional magnetic resonance images were obtained from veterans with PTSD (n = 50) and controls (combat and civilian controls; n = 54) to explore which network topology properties (degree and clustering coefficient) of which brain regions are associated with PTSD. Then, PTSD-associated brain regions were investigated before and after treatment. PTSD patients were subdivided in persistent (n = 22) and remitted PTSD patients (n = 17), and compared with combat controls (n = 22), who were also reassessed. Prior to treatment associations with PTSD were found for the degree of orbitofrontal, and temporoparietal brain regions, and for the clustering coefficient of the anterior cingulate cortex. No significant effects were found over the course of treatment. Our results are in line with previous resting state studies, showing resting state connectivity alterations in the salience network and default mode network in PTSD, and also highlight the importance of other brain regions. However, network metrics do not seem to change over the course of treatment. This study contributes to a better understanding of the psychopathology of PTSD. PMID:26900570

  7. Closed-form analysis of fiber-matrix interface stresses under thermo-mechanical loadings

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.; Crews, John H., Jr.

    1992-01-01

    Closed form techniques for calculating fiber matrix (FM) interface stresses, using repeating square and diamond regular arrays, were presented for a unidirectional composite under thermo-mechanical loadings. An Airy's stress function micromechanics approach from the literature, developed for calculating overall composite moduli, was extended in the present study to compute FM interface stresses for a unidirectional graphite/epoxy (AS4/3501-6) composite under thermal, longitudinal, transverse, transverse shear, and longitudinal shear loadings. Comparison with finite element results indicate excellent agreement of the FM interface stresses for the square array. Under thermal and longitudinal loading, the square array has the same FM peak stresses as the diamond array. The square array predicted higher stress concentrations under transverse normal and longitudinal shear loadings than the diamond array. Under transverse shear loading, the square array had a higher stress concentration while the diamond array had a higher radial stress concentration. Stress concentration factors under transverse shear and longitudinal shear loadings were very sensitive to fiber volume fraction. The present analysis provides a simple way to calculate accurate FM interface stresses for both the square and diamond array configurations.

  8. Perspectives on stress resilience and adolescent neurobehavioral function.

    PubMed

    Romeo, Russell D

    2015-01-01

    Interest in adolescence as a crucial stage of neurobehavioral maturation is growing, as is the concern of how stress may perturb this critical period of development. Though it is well recognized that stress-related vulnerabilities increase during adolescence, not all adolescent individuals are uniformly affected by stress nor do stressful experiences inevitability lead to negative outcomes. Indeed, many adolescents show resilience to stress-induced dysfunctions. However, relatively little is known regarding the mechanisms that may mediate resilience to stress in adolescence. The goal of this brief review is to bring together a few separate, yet related lines of research that highlight specific variables that may influence stress resilience during adolescence, including early life programming of the hypothalamic-pituitary-adrenal (HPA) axis, stress inoculation, and genetic predisposition. Though we are far from a clear understanding of the factors that mediate resistance to stress-induced dysfunctions, it is imperative that we identify and delineate these aspects of resilience to help adolescents reach their full potential, even in the face of adversity. PMID:27589663

  9. Perspectives on stress resilience and adolescent neurobehavioral function

    PubMed Central

    Romeo, Russell D.

    2014-01-01

    Interest in adolescence as a crucial stage of neurobehavioral maturation is growing, as is the concern of how stress may perturb this critical period of development. Though it is well recognized that stress-related vulnerabilities increase during adolescence, not all adolescent individuals are uniformly affected by stress nor do stressful experiences inevitability lead to negative outcomes. Indeed, many adolescents show resilience to stress-induced dysfunctions. However, relatively little is known regarding the mechanisms that may mediate resilience to stress in adolescence. The goal of this brief review is to bring together a few separate, yet related lines of research that highlight specific variables that may influence stress resilience during adolescence, including early life programming of the hypothalamic-pituitary-adrenal (HPA) axis, stress inoculation, and genetic predisposition. Though we are far from a clear understanding of the factors that mediate resistance to stress-induced dysfunctions, it is imperative that we identify and delineate these aspects of resilience to help adolescents reach their full potential, even in the face of adversity.

  10. Generation of χ(2) solitons from the Airy wave through the parametric instability.

    PubMed

    Mayteevarunyoo, Thawatchai; Malomed, Boris A

    2015-11-01

    Spontaneous creation of solitons in quadratic media by the downconversion (i.e., parametric instability against the generation of fundamental-frequency excitations) from the truncated Airy-wave (AW) mode in the second-harmonic component is studied. Parameter regions are identified for the generation of one, two, and three solitons, with additional small-amplitude "jets." Shares of the total power carried by individual solitons are found. Also considered are soliton patterns generated by the downconversion from a pair of AWs bending in opposite directions. PMID:26512490

  11. Test drilling and aquifer test in the Marburg schist near Mount Airy, Frederick County, Maryland

    USGS Publications Warehouse

    Meyer, Gerald

    1955-01-01

    This memorandum summarizes briefly the data obtained by test drilling and in an aquifer test at Mount Airy, Md. The tests were a part of the State - Federal cooperative study of the ground-water resources of Frederick County, and it is intended that a more complete analysis of the test data will be included in a future report describing the ground-water resource of Frederick County. The purpose of this memorandum is to make the test data immediately available to the general public. Mount Airy is located along the Carroll-Frederick County boundary bout 2 miles north of the intersection of U.S. Highway 40 with the county boundary. Its population is approximately 1,000. The municipal well field, consisting of two drilled wells (fig. 1) is in a valley about one-half mile west of the center of Mount Airy, within about 400 feet of a small stream, and north of Prospect Road. Well 1, about 40 feet north of Prospect Road, is 125 feet deep, 8 inches in diameter, and reportedly yielded 265 gallons per minute (gpm) in 1947 and 201 gpm in a half hour test in March 1955. The writer determined during the tests described in this memorandum that the well has about 34 feet of casing. Well 2, 85 feet north of well 1, is 96 feet deep, 8 inches in diameter, and reportedly yielded 120 gpm in 1947 and 127 gpm in a half hour test in March 1955. The wells are equipped with deep-well turbine pumps powered by electric motors. Cenorally only well 1 is used, and it is pumped for only a few short intervals each day to meet the water requirements of the town (about 75,000 - 80,000 gallons daily). The reported yields of these wells are considerably higher than the average for crystalline-rock wells in the Piedmont of Maryland. The test drilling was done under contract with Edward I. Brown, well driller, between May 3 and May 12, 1955. Water-supply facilities of the town of Mount Airy were kindly made available for the aquifer tests from May 22 to May 30, 1955. The pumping tests consisted of a

  12. Bound states of breathing Airy-Gaussian beams in nonlocal nonlinear medium

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaping

    2016-05-01

    With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results shows that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Especially, by tuning the phase difference between the two beams, we can steer the center of the bound AiG beams in nonlocal nonlinear media.

  13. Neuroendocrine circuits governing energy balance and stress regulation: functional overlap and therapeutic implications

    PubMed Central

    Ulrich-Lai, Yvonne M.; Ryan, Karen K.

    2014-01-01

    Significant co-morbidities between obesity-related metabolic disease and stress-related psychological disorders suggest important functional interactions between energy balance and brain stress integration. Largely overlapping neural circuits control these systems, and this anatomical arrangement optimizes opportunities for mutual influence. Here we first review the current literature identifying effects of metabolic neuroendocrine signals on stress regulation, and vice versa. Next, the contributions of reward driven food intake to these metabolic and stress interactions are discussed. Lastly, we consider the inter-relationships among metabolism, stress and reward in light of their important implications in the development of therapies for metabolism- or stress-related disease. PMID:24630812

  14. A Study on Propagation Characteristic of One-dimensional Stress Wave in Functionally Graded Armor Composites

    NASA Astrophysics Data System (ADS)

    Yang, S. Y.; Liu, X.; Cao, D. F.; Mei, H.; Lei, Z. T.; Liu, L. S.

    2013-03-01

    The development of Functionally Graded Materials (FGM) for energy-absorbing applications requires understanding of stress wave propagation in these structures in order to optimize their resistance to failure. One-dimensional stress wave in FGM composites under elastic and plastic wave loading have been investigated. The stress distributions through the thickness and stress status have been analyzed and some comparisons have been done with the materials of sharp interfaces (two-layered material). The results demonstrate that the gradient structure design greatly decreases the severity of the stress concentrations at the interfaces and there are no clear differences in stress distribution in FGM composites under elastic and plastic wave loading.

  15. Review: Interactions between temperament, stress, and immune function in cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stressors encountered by animals can pose economic problems for the livestock industry due to increased costs to the producer as well as the consumer. Stress can also adversely affect many physiological systems, including the reproductive and immune systems. In recent years, stress has been associat...

  16. Impaired Functional Connectivity in the Prefrontal Cortex: A Mechanism for Chronic Stress-Induced Neuropsychiatric Disorders

    PubMed Central

    Negrón-Oyarzo, Ignacio; Aboitiz, Francisco; Fuentealba, Pablo

    2016-01-01

    Chronic stress-related psychiatric diseases, such as major depression, posttraumatic stress disorder, and schizophrenia, are characterized by a maladaptive organization of behavioral responses that strongly affect the well-being of patients. Current evidence suggests that a functional impairment of the prefrontal cortex (PFC) is implicated in the pathophysiology of these diseases. Therefore, chronic stress may impair PFC functions required for the adaptive orchestration of behavioral responses. In the present review, we integrate evidence obtained from cognitive neuroscience with neurophysiological research with animal models, to put forward a hypothesis that addresses stress-induced behavioral dysfunctions observed in stress-related neuropsychiatric disorders. We propose that chronic stress impairs mechanisms involved in neuronal functional connectivity in the PFC that are required for the formation of adaptive representations for the execution of adaptive behavioral responses. These considerations could be particularly relevant for understanding the pathophysiology of chronic stress-related neuropsychiatric disorders. PMID:26904302

  17. Impaired Functional Connectivity in the Prefrontal Cortex: A Mechanism for Chronic Stress-Induced Neuropsychiatric Disorders.

    PubMed

    Negrón-Oyarzo, Ignacio; Aboitiz, Francisco; Fuentealba, Pablo

    2016-01-01

    Chronic stress-related psychiatric diseases, such as major depression, posttraumatic stress disorder, and schizophrenia, are characterized by a maladaptive organization of behavioral responses that strongly affect the well-being of patients. Current evidence suggests that a functional impairment of the prefrontal cortex (PFC) is implicated in the pathophysiology of these diseases. Therefore, chronic stress may impair PFC functions required for the adaptive orchestration of behavioral responses. In the present review, we integrate evidence obtained from cognitive neuroscience with neurophysiological research with animal models, to put forward a hypothesis that addresses stress-induced behavioral dysfunctions observed in stress-related neuropsychiatric disorders. We propose that chronic stress impairs mechanisms involved in neuronal functional connectivity in the PFC that are required for the formation of adaptive representations for the execution of adaptive behavioral responses. These considerations could be particularly relevant for understanding the pathophysiology of chronic stress-related neuropsychiatric disorders. PMID:26904302

  18. Asymptotics for the Covariance of the Airy2 Process

    NASA Astrophysics Data System (ADS)

    Shinault, Gregory; Tracy, Craig A.

    2011-04-01

    In this paper we compute some of the higher order terms in the asymptotic behavior of the two point function {P}({A}2(0)≤ s1,A2(t)≤ s2), extending the previous work of Adler and van Moerbeke (arXiv:math.PR/0302329; Ann. Probab. 33, 1326-1361, 2005) and Widom (J. Stat. Phys. 115, 1129-1134, 2004). We prove that it is possible to represent any order asymptotic approximation as a polynomial and integrals of the Painlevé II function q and its derivative q'. Further, for up to tenth order we give this asymptotic approximation as a linear combination of the Tracy-Widom GUE density function f 2 and its derivatives. As a corollary to this, the asymptotic covariance is expressed up to tenth order in terms of the moments of the Tracy-Widom GUE distribution.

  19. Intranasal Oxytocin Normalizes Amygdala Functional Connectivity in Posttraumatic Stress Disorder.

    PubMed

    Koch, Saskia B J; van Zuiden, Mirjam; Nawijn, Laura; Frijling, Jessie L; Veltman, Dick J; Olff, Miranda

    2016-07-01

    The neuropeptide oxytocin (OT) has been suggested as a promising pharmacological agent for medication-enhanced psychotherapy in posttraumatic stress disorder (PTSD) because of its anxiolytic and prosocial properties. We therefore investigated the behavioral and neurobiological effects of a single intranasal OT administration (40 IU) in PTSD patients. We conducted a randomized, placebo-controlled, cross-over resting-state fMRI study in male and female police officers with (n=37, 21 males) and without PTSD (n=40, 20 males). We investigated OT administration effects on subjective anxiety and functional connectivity of basolateral (BLA) and centromedial (CeM) amygdala subregions with prefrontal and salience processing areas. In PTSD patients, OT administration resulted in decreased subjective anxiety and nervousness. Under placebo, male PTSD patients showed diminished right CeM to left ventromedial prefrontal cortex (vmPFC) connectivity compared with male trauma-exposed controls, which was reinstated after OT administration. Additionally, female PTSD patients showed enhanced right BLA to bilateral dorsal anterior cingulate cortex (dACC) connectivity compared with female trauma-exposed controls, which was dampened after OT administration. Although caution is warranted, our findings tentatively suggest that OT has the potential to diminish anxiety and fear expression of the amygdala in PTSD, either via increased control of the vmPFC over the CeM (males) or via decreased salience processing of the dACC and BLA (females). Our findings add to accumulating evidence that OT administration could potentially enhance treatment response in PTSD. PMID:26741286

  20. Muscle Spindle Traffic in Functionally Unstable Ankles During Ligamentous Stress

    PubMed Central

    Needle, Alan R.; Charles B. (Buz), Swanik; Farquhar, William B.; Thomas, Stephen J.; Rose, William C.; Kaminski, Thomas W.

    2013-01-01

    Context: Ankle sprains are common in athletes, with functional ankle instability (FAI) developing in approximately half of cases. The relationship between laxity and FAI has been inconclusive, suggesting that instability may be caused by insufficient sensorimotor function and dynamic restraint. Research has suggested that deafferentation of peripheral mechanoreceptors potentially causes FAI; however, direct evidence confirming peripheral sensory deficits has been elusive because previous investigators relied upon subjective proprioceptive tests. Objective: To develop a method for simultaneously recording peripheral sensory traffic, joint forces, and laxity and to quantify differences between healthy ankles and those with reported instability. Design: Case-control study. Setting: University laboratory. Patients or Other Participants: A total of 29 participants (age = 20.9 ± 2.2 years, height = 173.1 ± 8.9 cm, mass = 74.5 ± 12.7 kg) stratified as having healthy (HA, n = 19) or unstable ankles (UA, n = 10). Intervention(s): Sensory traffic from muscle spindle afferents in the peroneal nerve was recorded with microneurography while anterior (AP) and inversion (IE) stress was applied to ligamentous structures using an ankle arthrometer under test and sham conditions. Main Outcome Measure(s): Laxity (millimeters or degrees) and amplitude of sensory traffic (percentage) were determined at 0, 30, 60, 90, and 125 N of AP force and at 0, 1, 2, 3, and 4 Nm of IE torque. Two-factor repeated-measures analyses of variance were used to determine differences between groups and conditions. Results: No differences in laxity were observed between groups (P > .05). Afferent traffic increased with increased force and torque in test trials (P < .001). The UA group displayed decreased afferent activity at 30 N of AP force compared with the HA group (HA: 30.2% ± 9.9%, UA: 17.1% ± 16.1%, P < .05). Conclusions: The amplitude of sensory traffic increased simultaneously with greater

  1. Evolving stresses in latex films as a function of temperature.

    PubMed

    Yow, Huai Nyin; Beristain, Itxaso; Goikoetxea, Monika; Barandiaran, Maria J; Routh, Alexander F

    2010-05-01

    Latex films were dried on a flexible substrate, and the substrate deflection was monitored over time to give an averaged film stress-evolution profile. Films were dried at various temperatures below and above the minimum film-formation temperature of the latex dispersion. The effect of polymer rheology, which is a temperature-dependent parameter, on film formation, was investigated. The reliability of the Stoney model in predicting film stress from substrate curvature was also examined and compared to the Euler-Bernoulli model. It was shown that the linearized Stoney model was unsuitable for the larger measured stresses. PMID:20387802

  2. The Role of Family Functioning in the Stress Process of Dementia Caregivers: A Structural Family Framework

    ERIC Educational Resources Information Center

    Mitrani, Victoria B.; Lewis, John E.; Feaster, Daniel J.; Czaja, Sara J.; Eisdorfer, Carl; Schulz, Richard; Szapocznik, Jose

    2006-01-01

    Purpose: The purpose of the study was to evaluate the role of family functioning in the stress process in a sample of caregivers of dementia patients by using a structural family framework. The stress-process model of caregiver distress included family functioning as an intervening variable in the relationship between objective burden and…

  3. Effect of citrocard on functional reserves of the heart under conditions of chronic stress.

    PubMed

    Perfilova, V N; Tyurenkov, I N; Lebedeva, S A; Volotova, E V; Berestovitskaya, V M; Vasil'eva, O S

    2007-07-01

    Chronic stress exposure produces a damaging effect on the myocardium and reduces its functional (inotropic) reserves. Citrocard (50 mg/kg) and fenibut (50 mg/kg) prevent stress effects: animals receiving these preparations demonstrate higher contraction and relaxation rates and higher left-ventricular pressure during functional tests (volume load and maximum isometric load). PMID:18256742

  4. Neural traces of stress: cortisol related sustained enhancement of amygdala-hippocampal functional connectivity

    PubMed Central

    Vaisvaser, Sharon; Lin, Tamar; Admon, Roee; Podlipsky, Ilana; Greenman, Yona; Stern, Naftali; Fruchter, Eyal; Wald, Ilan; Pine, Daniel S.; Tarrasch, Ricardo; Bar-Haim, Yair; Hendler, Talma

    2013-01-01

    Stressful experiences modulate neuro-circuitry function, and the temporal trajectory of these alterations, elapsing from early disturbances to late recovery, heavily influences resilience and vulnerability to stress. Such effects of stress may depend on processes that are engaged during resting-state, through active recollection of past experiences and anticipation of future events, all known to involve the default mode network (DMN). By inducing social stress and acquiring resting-state functional magnetic resonance imaging (fMRI) before stress, immediately following it, and 2 h later, we expanded the time-window for examining the trajectory of the stress response. Throughout the study repeated cortisol samplings and self-reports of stress levels were obtained from 51 healthy young males. Post-stress alterations were investigated by whole brain resting-state functional connectivity (rsFC) of two central hubs of the DMN: the posterior cingulate cortex (PCC) and hippocampus. Results indicate a ’recovery’ pattern of DMN connectivity, in which all alterations, ascribed to the intervening stress, returned to pre-stress levels. The only exception to this pattern was a stress-induced rise in amygdala-hippocampal connectivity, which was sustained for as long as 2 h following stress induction. Furthermore, this sustained enhancement of limbic connectivity was inversely correlated to individual stress-induced cortisol responsiveness (AUCi) and characterized only the group lacking such increased cortisol (i.e., non-responders). Our observations provide evidence of a prolonged post-stress response profile, characterized by both the comprehensive balance of most DMN functional connections and the distinct time and cortisol dependent ascent of intra-limbic connectivity. These novel insights into neuro-endocrine relations are another milestone in the ongoing search for individual markers in stress-related psychopathologies. PMID:23847492

  5. Computer processing of Mars Odyssey THEMIS IR imaging, MGS MOLA altimetry and Mars Express stereo imaging to locate Airy-0, the Mars prime meridian reference

    NASA Astrophysics Data System (ADS)

    Duxbury, Thomas; Neukum, Gerhard; Smith, David E.; Christensen, Philip; Neumann, Gregory; Albee, Arden; Caplinger, Michael; Seregina, N. V.; Kirk, Randolph L.

    The small crater Airy-0 was selected from Mariner 9 images to be the reference for the Mars prime meridian. Initial analyses were made in year 2000 to tie Viking Orbiter and Mars Orbiter Camera images of Airy-0 to the evolving Mars Orbiter Laser Altimeter global digital terrain model to improve the location accuracy of Airy-0. Based upon this tie and radiometric tracking of landers / rovers from earth, new expressions for the Mars spin axis direction, spin rate and prime meridian epoch value were produced to define the orientation of the Martian surface in inertial space over time. Now that the Mars Global Surveyor mission and the Mars Orbiter Laser Altimeter global digital terrain model are complete, a more exhaustive study has been performed to determine the location of Airy-0 relative to the global terrain grid. THEMIS IR image cubes of the Airy and Gale crater regions were tied to the global terrain grid using precision stereo photogrammetric image processing techniques. The Airy-0 location was determined to be within 50 meters of the currently defined IAU prime meridian, with this offset at the limiting absolute accuracy of the global terrain grid. Additional outputs of this study were a controlled multi-band photomosaic of Airy, precision alignment and geometric models of the ten THEMIS IR bands and a controlled multi-band photomosaic of Gale crater used to validate the Mars Surface Laboratory operational map products supporting their successful landing on Mars.

  6. Chlamydomonas reinhardtii, a model system for functional validation of abiotic stress responsive genes.

    PubMed

    Hema, R; Senthil-Kumar, M; Shivakumar, S; Chandrasekhara Reddy, P; Udayakumar, M

    2007-08-01

    Stress tolerance is a multigenic character and there are many stress responsive genes, which are stress specific. Although many of these have been cloned, their functional significance remains fragmentary. Hence it is important to identify the relevant stress genes involved in altering the metabolism for adaptation. Overexpression is one of the several approaches and Chlamydomonas is a suitable system to study the functional relevance of stress genes. Stress responses can only be assessed on prior exposure to sublethal induction stress. In this study the acclimation response of Chlamydomonas was assessed for different abiotic stresses using physiological screens like chlorophyll stability, membrane damage, cell viability, accumulation of free radicals, survival and recovery growth. We demonstrate that Chlamydomonas responds to diverse stresses and is a potential system to study the relevance of stress genes. The relevance of choline oxidase A (codA), a key enzyme in glycinebetaine biosynthesis, was examined by developing transformants expressing codA gene from Arthrobacter globiformis. Southern positive transformants showed enhanced accumulation of glycinebetaine. The transformants also showed enhanced growth under salinity, high light coupled with methylviologen-induced oxidative stress, high temperature and cold stress. However the transgenics were not tolerant to PEG-mediated simulated osmotic stress, LiCl, menadione and UV stress. Increased cell survival and decreased chlorophyll degradation in transformants under acclimated conditions further confirmed the relevance of codA in imparting stress tolerance. Our results indicated that the relevance of stress responsive genes can be efficiently validated for diverse abiotic stresses using Chlamydomonas system. PMID:17431668

  7. Lactobacillus casei combats acid stress by maintaining cell membrane functionality.

    PubMed

    Wu, Chongde; Zhang, Juan; Wang, Miao; Du, Guocheng; Chen, Jian

    2012-07-01

    Lactobacillus casei strains have traditionally been recognized as probiotics and frequently used as adjunct culture in fermented dairy products where lactic acid stress is a frequently encountered environmental condition. We have investigated the effect of lactic acid stress on the cell membrane of L. casei Zhang [wild type (WT)] and its acid-resistant mutant Lbz-2. Both strains were grown under glucose-limiting conditions in chemostats; following challenge by low pH, the cell membrane stress responses were investigated. In response to acid stress, cell membrane fluidity decreased and its fatty acid composition changed to reduce the damage caused by lactic acid. Compared with the WT, the acid-resistant mutant exhibited numerous survival advantages, such as higher membrane fluidity, higher proportions of unsaturated fatty acids, and higher mean chain length. In addition, cell integrity analysis showed that the mutant maintained a more intact cellular structure and lower membrane permeability after environmental acidification. These results indicate that alteration in membrane fluidity, fatty acid distribution, and cell integrity are common mechanisms utilized by L. casei to withstand severe acidification and to reduce the deleterious effect of lactic acid on the cell membrane. This detailed comparison of cell membrane responses between the WT and mutant add to our knowledge of the acid stress adaptation and thus enable new strategies to be developed aimed at improving the industrial performance of this species under acid stress. PMID:22366811

  8. Evolution of finite energy Airy pulses and soliton generation in optical fibers with cubic-quintic nonlinearity.

    PubMed

    Zhong, Xianqiong; Du, Xiantong; Cheng, Ke

    2015-11-16

    We numerically simulate the propagation of finite energy Airy pulses in optical fibers with cubic-quintic nonlinearity and analyze the effects of quintic nonlinear parameters and soliton order number on their evolution properties. The soliton pulses are observed, whose peak amplitudes and corresponding temporal positions will vary with the propagation distance. Depending on different quintic nonlinearity parameters and soliton order number, the soliton pulse temporal positions exhibit weak decayed oscillations and then nearly linearly shift to leading or trailing edge of the Airy wavepacket, or tend to fixed positions, and the peak amplitudes also exhibit decayed oscillations but with different oscillation amplitude and central values. For large soliton order number, the soliton pulses are considerably compressed. Other weak dispersive wave pulses will appear near the main soliton pulses and gradually depart from the main soliton pulses. In the case of small soliton order, despite their considerable energy attenuation, the main lobes and even minority of the neighboring side lobes of the Airy pulses can still recover from the energy transfer to the soliton pulses and the dispersive wave pulses and maintain their unique properties of self-healing and self-acceleration in time for a very long distance. In the case of large soliton order, however, the Airy wavepacket only remains its very weak background and even disappears quickly. PMID:26698430

  9. The Role of Stress Exposure and Family Functioning in Internalizing Outcomes of Urban Families

    PubMed Central

    Henry, David B.; Tolan, Patrick H.; Strachan, Martha K.

    2013-01-01

    Although research suggests that stress exposure and family functioning are associated with internalizing problems in adolescents and caregivers, surprisingly few studies have investigated the mechanisms that underlie this association. To determine whether family functioning buffers the development of internalizing problems in stress-exposed families, we assessed the relation between stress exposure, family functioning, and internalizing symptoms among a large sample of inner-city male youth and their caregivers living in poverty across five waves of data collection. We hypothesized that stress exposure and family functioning would predict development of subsequent youth and caregiver internalizing problems and that family functioning would moderate this relation, with higher functioning families demonstrating greater resiliency to stress exposure. We used a longitudinal, prospective design to evaluate whether family functioning (assessed at waves one through four) activated or buffered the effects of stress exposure (assessed at wave one) on subsequent internalizing symptoms (assessed at waves four and five). Stress from Developmental Transitions and family functioning were significant predictors of depressive symptoms and anxiety in youth; however, family functioning did not moderate the relation. Family functioning mediated the relation between stress from Daily Hassles and internalizing outcomes suggesting that poor parenting practices, low structure, and low emotional cohesion activate depression and anxiety in youth exposed to chronic and frequent everyday stressors. Surprisingly, only family functioning predicted depressive symptoms in caregivers. Results validate the use of a comprehensive, multi-informant assessment of stress when investigating internalizing outcomes in youth and support using family-based interventions in the treatment and prevention of internalizing. PMID:25601821

  10. Evaluation of a functional medicine approach to treating fatigue, stress, and digestive issues in women.

    PubMed

    Cutshall, Susanne M; Bergstrom, Larry R; Kalish, Daniel J

    2016-05-01

    Fatigue, stress, and digestive disorders are common among adults, especially women. We conducted a 28-week pilot study to assess the efficacy of a functional medicine approach to improving stress, energy, fatigue, digestive issues, and quality of life in middle-aged women. Findings showed significant improvements in many stress, fatigue, and quality-of-life measures. The treatment program increased mean salivary dehydroepiandrosterone levels and the cortisol-dehydroepiandrosterone ratio. Stool sample analyses suggested that these treatments reduced Helicobacter pylori infections. This study suggests that functional medicine may be an effective approach to managing stress and gastrointestinal symptoms. PMID:27157963

  11. Development of Maladaptive Coping: A Functional Adaptation to Chronic, Uncontrollable Stress

    PubMed Central

    Wadsworth, Martha E.

    2015-01-01

    Health disparities are rooted in childhood and stem from adverse early environments that damage physiologic stress-response systems. Developmental psychobiological models of the effects of chronic stress account for both the negative effects of a stress-response system calibrated to a dangerous and unpredictable environment from a health perspective, and the positive effects of such an adaptively calibrated stress response from a functional perspective. Our research suggests that contexts that produce functionally adapted physiologic responses to stress also encourage a functionally adapted coping response—coping that can result in maladjustment in physical and mental health, but enables children to grow and develop within those contexts. In this article, I highlight the value of reframing maladaptive coping as functional adaptation to understand more completely the development of children’s coping in different contexts, and the value of such a conceptual shift for coping-based theory, research, and intervention. PMID:26019717

  12. Coronary flow and left ventricular function during environmental stress.

    NASA Technical Reports Server (NTRS)

    Erickson, H. H.; Adams, J. D.; Stone, H. L.; Sandler, H.

    1972-01-01

    A canine model was used to study the effects of different environmental stresses on the heart and coronary circulation. The heart was surgically instrumented to measure coronary blood flow, left ventricular pressure, and other cardiovascular variables. Coronary flow was recorded by telemetry. Physiologic data were processed and analyzed by analog and digital computers. By these methods the physiologic response to altitude hypoxia, carbon monoxide, hypercapnia, acceleration, exercise, and the interaction of altitude hypoxia and carbon monoxide were described. The effects of some of these stresses on the heart and coronary circulation are discussed.

  13. Central circulatory hemodynamics as a function of gravitational stress

    NASA Technical Reports Server (NTRS)

    Latham, Rick D.; White, C. D.; Fanton, J. W.; Owens, R. W.; Barber, J. F.; Lewkowski, B. E.; Goff, O. T.

    1991-01-01

    This study focuses on an evaluation of the central hemodynamics in a nonhuman primate model to variations in gravitational states. The baboon, phylogenectically close to man, was chosen as the human surrogate. The study environments selected are head-down and head-up tilt in the physiology laboratory, centrifugation to test hypergravic stress, and parabolic flights to test transient acute responses to microgravity.

  14. Production of Functional Proteins: Balance of Shear Stress and Gravity

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas John (Inventor); Hammond, Timothy Grant (Inventor); Haysen, James Howard (Inventor)

    2005-01-01

    The present invention provides for a method of culturing cells and inducing the expression of at least one gene in the cell culture. The method provides for contacting the cell with a transcription factor decoy oligonucleotide sequence directed against a nucleotide sequence encoding a shear stress response element.

  15. Functional genomics of abiotic stress responses in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable crop production in the U.S., as well as in other areas of the world, will rely upon the crop’s ability to yield under progressively limiting conditions: marginal soils, decreased water availability, and oftentimes critical temperature stress. Enhanced understanding of the physiological...

  16. Stressful Life Event Influences on Positive and Negative Psychological Functioning.

    ERIC Educational Resources Information Center

    McGowan, John R.; Cohen, Lawrence H.

    Some research has suggested that positive life events may interact with negative life events during periods of high stress to buffer the effects of negative events. The relationships among positive and negative life events and positive and negative psychological status were examined in an investigation of the direct and mediating effects of…

  17. Stress-induced changes in skin barrier function in healthy women.

    PubMed

    Altemus, M; Rao, B; Dhabhar, F S; Ding, W; Granstein, R D

    2001-08-01

    Despite clear exacerbation of several skin disorders by stress, the effect of psychologic or exertional stress on human skin has not been well studied. We investigated the effect of three different stressors, psychologic interview stress, sleep deprivation, and exercise, on several dermatologic measures: transepidermal water loss, recovery of skin barrier function after tape stripping, and stratum corneum water content (skin conductance). We simultaneously measured the effects of stress on plasma levels of several stress-response hormones and cytokines, natural killer cell activity, and absolute numbers of peripheral blood leukocytes. Twenty-five women participated in a laboratory psychologic interview stress, 11 women participated in one night of sleep deprivation, and 10 women participated in a 3 d exercise protocol. The interview stress caused a delay in the recovery of skin barrier function, as well as increases in plasma cortisol, norepinephrine, interleukin-1beta and interleukin-10, tumor necrosis factor-alpha, and an increase in circulating natural killer cell activity and natural killer cell number. Sleep deprivation also decreased skin barrier function recovery and increased plasma interleukin-1beta, tumor necrosis factor-alpha, and natural killer cell activity. The exercise stress did not affect skin barrier function recovery, but caused an increase in natural killer cell activity and circulating numbers of both cytolytic T lymphocytes and helper T cells. In addition, cytokine responses to the interview stress were inversely correlated with changes in barrier function recovery. These results suggest that acute psychosocial and sleep deprivation stress disrupts skin barrier function homeostasis in women, and that this disruption may be related to stress-induced changes in cytokine secretion. PMID:11511309

  18. Endoplasmic reticulum stress and the on site function of resident PTP1B.

    PubMed

    Popov, Doina

    2012-06-15

    Growing evidence links the stress at the endoplasmic reticulum (ER) to pathologies such as diabetes mellitus, obesity, liver, heart, renal and neurodegenerative diseases, endothelial dysfunction, atherosclerosis, and cancer. Therefore, identification of molecular pathways beyond ER stress and their appropriate modulation might alleviate the stress, and direct toward novel tools to fight this disturbance. An interesting resident of the ER membrane is protein tyrosine phosphatase 1B (PTP1B), an enzyme that negatively regulates insulin and leptin signaling, contributing to insulin and leptin resistance. Recently, new functions of PTP1B have been established linked to ER stress response. This review evaluates the novel data on ER stressors, discusses the mechanisms beyond PTP1B function in the ER stress response, and emphasizes the potential therapeutic exploitation of PTP1B to relieve ER stress. PMID:22609202

  19. Protective function of nitric oxide on marine phytoplankton under abiotic stresses.

    PubMed

    Li, Peifeng; Liu, Chun-Ying; Liu, Huanhuan; Zhang, Qiang; Wang, Lili

    2013-09-01

    As an important signaling molecule, nitric oxide (NO) plays diverse physiological functions in plants, which has gained particular attention in recent years. We investigated the roles of NO in the growth of marine phytoplankton Platymonas subcordiforms and Skeletonema costatum under abiotic stresses. The growth of these two microalgae was obviously inhibited under non-metal stress (sodium selenium, Na2SeO3), heavy metal stress (lead nitrate, Pb(NO3)2), pesticide stress (methomyl) and UV radiation stress. After the addition of different low concentrations of exogenous NO (10(-10)-10(-8) mol L(-1)) twice each day during cultivation, the growth of these two microalgae was obviously promoted. Results showed that NO could relieve the oxidative stresses to protect the growth of the two microalgae. For different environmental stress, there is a different optimum NO concentration for marine phytoplankton. It is speculated that the protective effect of NO is related to its antioxidant ability. PMID:23810732

  20. Free-edge stress analysis of functionally graded material layered biocomposite laminates.

    PubMed

    Huang, Bin; Kim, Heung Soo

    2014-10-01

    A stress function based theory is proposed to obtain free-edge stress distributions for three-dimensional, orthotropic, linearly elastic rectangular biocomposite laminates with surface-bonded functionally graded materials (FGM). The assumed stress fields automatically satisfy the pointwise equilibrium equation, as well as traction-free and free edge boundary conditions. The complementary virtual work principle, followed by the general eigenvalue solution procedure, is used to obtain 3-D free edge stress states. A typical stacking sequence of composite laminate is used as numerical investigation with surface bonded FGMs. It is shown that with proper exponential factor of FGMs, the interlaminar stresses at the FGM layer interface can be reduced significantly, in return to prevent debonding of FGM layers. This approach can be useful in the design of functionally graded material layered biocomposite structures. PMID:25942808

  1. Function of isoprenoid quinones and chromanols during oxidative stress in plants.

    PubMed

    Kruk, Jerzy; Szymańska, Renata; Nowicka, Beatrycze; Dłużewska, Jolanta

    2016-09-25

    Isoprenoid quinones and chromanols in plants fulfill both signaling and antioxidant functions under oxidative stress. The redox state of the plastoquinol pool (PQ-pool), which is modulated by interaction with reactive oxygen species (ROS) during oxidative stress, has a major regulatory function in both short- and long-term acclimatory responses. By contrast, the scavenging of ROS by prenyllipids affects signaling pathways where ROS play a role as signaling molecules. As the primary antioxidants, isoprenoid quinones and chromanols are synthesized under high-light stress in response to any increased production of ROS. During photo-oxidative stress, these prenyllipids are continuously synthesized and oxidized to other compounds. In turn, their oxidation products (hydroxy-plastochromanol, plastoquinol-C, plastoquinone-B) can still have an antioxidant function. The oxidation products of isoprenoid quinones and chromanols formed specifically in the face of singlet oxygen, can be indicators of singlet oxygen stress. PMID:26970272

  2. Stress-Induced EGFR Trafficking: Mechanisms, Functions, and Therapeutic Implications.

    PubMed

    Tan, Xiaojun; Lambert, Paul F; Rapraeger, Alan C; Anderson, Richard A

    2016-05-01

    Epidermal growth factor receptor (EGFR) has fundamental roles in normal physiology and cancer, making it a rational target for cancer therapy. Surprisingly, however, inhibitors that target canonical, ligand-stimulated EGFR signaling have proven to be largely ineffective in treating many EGFR-dependent cancers. Recent evidence indicates that both intrinsic and therapy-induced cellular stress triggers robust, noncanonical pathways of ligand-independent EGFR trafficking and signaling, which provides cancer cells with a survival advantage and resistance to therapeutics. Here, we review the mechanistic regulation of noncanonical EGFR trafficking and signaling, and the pathological and therapeutic stresses that activate it. We also discuss the implications of this pathway in clinical treatment of EGFR-overexpressing cancers. PMID:26827089

  3. A NAP-Family Histone Chaperone Functions in Abiotic Stress Response and Adaptation.

    PubMed

    Tripathi, Amit K; Pareek, Ashwani; Singla-Pareek, Sneh Lata

    2016-08-01

    Modulation of gene expression is one of the most significant molecular mechanisms of abiotic stress response in plants. Via altering DNA accessibility, histone chaperones affect the transcriptional competence of genomic loci. However, in contrast to other factors affecting chromatin dynamics, the role of plant histone chaperones in abiotic stress response and adaptation remains elusive. Here, we studied the physiological function of a stress-responsive putative rice (Oryza sativa) histone chaperone of the NAP superfamily: OsNAPL6. We show that OsNAPL6 is a nuclear-localized H3/H4 histone chaperone capable of assembling a nucleosome-like structure. Utilizing overexpression and knockdown approaches, we found a positive correlation between OsNAPL6 expression levels and adaptation to multiple abiotic stresses. Results of comparative transcriptome profiling and promoter-recruitment studies indicate that OsNAPL6 functions during stress response via modulation of expression of various genes involved in diverse functions. For instance, we show that OsNAPL6 is recruited to OsRad51 promoter, activating its expression and leading to more efficient DNA repair and abrogation of programmed cell death under salinity and genotoxic stress conditions. These results suggest that the histone chaperone OsNAPL6 may serve a regulatory role in abiotic stress physiology possibly via modulating nucleosome dynamics at various stress-associated genomic loci. Taken together, our findings establish a hitherto unknown link between histone chaperones and abiotic stress response in plants. PMID:27342307

  4. A NAP-Family Histone Chaperone Functions in Abiotic Stress Response and Adaptation1[OPEN

    PubMed Central

    Pareek, Ashwani; Singla-Pareek, Sneh Lata

    2016-01-01

    Modulation of gene expression is one of the most significant molecular mechanisms of abiotic stress response in plants. Via altering DNA accessibility, histone chaperones affect the transcriptional competence of genomic loci. However, in contrast to other factors affecting chromatin dynamics, the role of plant histone chaperones in abiotic stress response and adaptation remains elusive. Here, we studied the physiological function of a stress-responsive putative rice (Oryza sativa) histone chaperone of the NAP superfamily: OsNAPL6. We show that OsNAPL6 is a nuclear-localized H3/H4 histone chaperone capable of assembling a nucleosome-like structure. Utilizing overexpression and knockdown approaches, we found a positive correlation between OsNAPL6 expression levels and adaptation to multiple abiotic stresses. Results of comparative transcriptome profiling and promoter-recruitment studies indicate that OsNAPL6 functions during stress response via modulation of expression of various genes involved in diverse functions. For instance, we show that OsNAPL6 is recruited to OsRad51 promoter, activating its expression and leading to more efficient DNA repair and abrogation of programmed cell death under salinity and genotoxic stress conditions. These results suggest that the histone chaperone OsNAPL6 may serve a regulatory role in abiotic stress physiology possibly via modulating nucleosome dynamics at various stress-associated genomic loci. Taken together, our findings establish a hitherto unknown link between histone chaperones and abiotic stress response in plants. PMID:27342307

  5. Serotonin and pituitary-adrenal function. [in rat under stress

    NASA Technical Reports Server (NTRS)

    Berger, P. A.; Barchas, J. D.; Vernikos-Danellis, J.

    1974-01-01

    An investigation is conducted to evaluate the response of the pituitary-adrenal system to a stress stimulus in the rat. In the investigation brain serotonin synthesis was inhibited with p-chlorophenylalanine. In other tests the concentration of serotonin was enhanced with precursors such as tryptophan or 5-hydroxytryptophan. On the basis of the results obtained in the study it is speculated that in some disease states there is a defect in serotonergic neuronal processes which impairs pituitary-adrenal feedback mechanisms.

  6. Mitochondrial functions modulate neuroendocrine, metabolic, inflammatory, and transcriptional responses to acute psychological stress

    PubMed Central

    Picard, Martin; McManus, Meagan J.; Gray, Jason D.; Nasca, Carla; Moffat, Cynthia; Kopinski, Piotr K.; Seifert, Erin L.; McEwen, Bruce S.; Wallace, Douglas C.

    2015-01-01

    The experience of psychological stress triggers neuroendocrine, inflammatory, metabolic, and transcriptional perturbations that ultimately predispose to disease. However, the subcellular determinants of this integrated, multisystemic stress response have not been defined. Central to stress adaptation is cellular energetics, involving mitochondrial energy production and oxidative stress. We therefore hypothesized that abnormal mitochondrial functions would differentially modulate the organism’s multisystemic response to psychological stress. By mutating or deleting mitochondrial genes encoded in the mtDNA [NADH dehydrogenase 6 (ND6) and cytochrome c oxidase subunit I (COI)] or nuclear DNA [adenine nucleotide translocator 1 (ANT1) and nicotinamide nucleotide transhydrogenase (NNT)], we selectively impaired mitochondrial respiratory chain function, energy exchange, and mitochondrial redox balance in mice. The resulting impact on physiological reactivity and recovery from restraint stress were then characterized. We show that mitochondrial dysfunctions altered the hypothalamic–pituitary–adrenal axis, sympathetic adrenal–medullary activation and catecholamine levels, the inflammatory cytokine IL-6, circulating metabolites, and hippocampal gene expression responses to stress. Each mitochondrial defect generated a distinct whole-body stress-response signature. These results demonstrate the role of mitochondrial energetics and redox balance as modulators of key pathophysiological perturbations previously linked to disease. This work establishes mitochondria as stress-response modulators, with implications for understanding the mechanisms of stress pathophysiology and mitochondrial diseases. PMID:26627253

  7. Stress-induced alterations in large-scale functional networks of the rodent brain.

    PubMed

    Henckens, Marloes J A G; van der Marel, Kajo; van der Toorn, Annette; Pillai, Anup G; Fernández, Guillén; Dijkhuizen, Rick M; Joëls, Marian

    2015-01-15

    Stress-related psychopathology is associated with altered functioning of large-scale brain networks. Animal research into chronic stress, one of the most prominent environmental risk factors for development of psychopathology, has revealed molecular and cellular mechanisms potentially contributing to human mental disease. However, so far, these studies have not addressed the system-level changes in extended brain networks, thought to critically contribute to mental disorders. We here tested the effects of chronic stress exposure (10 days immobilization) on the structural integrity and functional connectivity patterns in the brain, using high-resolution structural MRI, diffusion kurtosis imaging, and resting-state functional MRI, while confirming the expected changes in neuronal dendritic morphology using Golgi-staining. Stress effectiveness was confirmed by a significantly lower body weight and increased adrenal weight. In line with previous research, stressed animals displayed neuronal dendritic hypertrophy in the amygdala and hypotrophy in the hippocampal and medial prefrontal cortex. Using independent component analysis of resting-state fMRI data, we identified ten functional connectivity networks in the rodent brain. Chronic stress appeared to increase connectivity within the somatosensory, visual, and default mode networks. Moreover, chronic stress exposure was associated with an increased volume and diffusivity of the lateral ventricles, whereas no other volumetric changes were observed. This study shows that chronic stress exposure in rodents induces alterations in functional network connectivity strength which partly resemble those observed in stress-related psychopathology. Moreover, these functional consequences of stress seem to be more prominent than the effects on gross volumetric change, indicating their significance for future research. PMID:25462693

  8. The Impact of Children with High-Functioning Autism on Parental Stress, Sibling Adjustment, and Family Functioning

    ERIC Educational Resources Information Center

    Rao, Patricia A.; Beidel, Deborah C.

    2009-01-01

    The article discuses a study conducted to investigate the impact of children with high-functioning autism (HFA) on parental stress, sibling adjustment, and family functioning; the study involves a sample of parents of 15 children with HFA and parents of 15 matched control children who completed questionnaires measuring the dependent variables. The…

  9. Propagation of an Airy-Gaussian vortex beam in linear and nonlinear media

    NASA Astrophysics Data System (ADS)

    Chen, Chidao; Peng, Xi; Chen, Bo; Peng, Yulian; Zhou, Meiling; Yang, Xiangbo; Deng, Dongmei

    2016-05-01

    We investigate the propagation of an Airy-Gaussian vortex (AiGV) beam in free space and Kerr media. It is interesting to see that the beam will perform self-healing and main lobe focusing both in free space and Kerr media when the vortex locates at the center of the plane. By controlling the number of the topological charge, the beam distribution factor χ 0 and the position of the vortex, we can control the intensity distribution of the AiGV beam in the out plane both in free space and Kerr media. It is found that when the vortex is close to the center of the plane, it has a strong effect on the intensity distribution of the beam. When the beam propagates in the number of the topological charge, the partial collapse will take place even with low initial input power. We find that the main lobe focusing contributes to this partial collapse.

  10. Predicting the past: ancient eclipses and Airy, Newcomb, and Huxley on the authority of science.

    PubMed

    Stanley, Matthew

    2012-06-01

    Greek historical accounts of ancient eclipses were an important, if peculiar, focus of scientific attention in the nineteenth century. Victorian-era astronomers tried to correct the classical histories using scientific methods, then used those histories as data with which to calibrate their lunar theories, then rejected the histories as having any relevance at all. The specific dating of these eclipses--apparently a simple exercise in celestial mechanics--became bound up with tensions between scientific and humanistic approaches to the past as well as with wider social debates over the power and authority of science in general. The major figures discussed here, including G. B. Airy, Simon Newcomb, and T. H. Huxley, argued that the critical question was whether science could speak authoritatively about the past. To them, the ability of science to talk about the past indicated its power to talk about the future; it was also the fulcrum of fierce boundary disputes among science, history, and religion. PMID:22908421

  11. The Stress-Buffering Effects of Functional Social Support on Ambulatory Blood Pressure

    PubMed Central

    Bowen, Kimberly S.; Uchino, Bert N.; Birmingham, Wendy; Carlisle, McKenzie; Smith, Timothy W.; Light, Kathleen C.

    2014-01-01

    Objective Social support is a reliable predictor of cardiovascular health. According to the buffering hypothesis, stress is one mechanism by which support is able to affect physiological processes. However, most of the experimental evidence for the hypothesis comes from laboratory studies. Ambulatory blood pressure protocols examine participants in their natural environment, where they are more likely to encounter personally relevant real-world stressors. Furthermore, prior work shows that examining support by its specific functional components reveals additional independent links to health. Methods The current study aimed to examine the stress-buffering effects of functional social support on ABP. 188 participants completed a one day ABP assessment along with measures of functional social support and both global perceived stress and momentary stress at time of reading. Results Results indicated main effects for both stress measures. Global support, emotional, tangible, and informational support only moderated the effects of momentary stress, but not global stress, in predicting ABP. Informational support was the most consistent stress-buffering predictor of ABP, predicting both ambulatory SBP and DBP. Conclusions The predicted values in ABP for informational support achieved health-relevant differences, emphasizing the value of examining functional support beyond global support alone. PMID:24245843

  12. Parent Stress, Family Functioning and Social Support in Families of Young Handicapped Children.

    ERIC Educational Resources Information Center

    Dyson, Lily

    This study compared parent stress, family functioning, and social support in 55 families with a developmentally handicapped child (ages 0-7) and 55 families with a nonhandicapped child. Findings indicated that a young handicapped child did induce greater stress in his parents than did a nonhandicapped child. Parents of handicapped children…

  13. The Reduction of Occupational Stress among Elderly Lawyers: The Creation of a Functional Niche.

    ERIC Educational Resources Information Center

    Meltzer, Michael W.

    1981-01-01

    Examined how older lawyers function in a high stress occupation using data from a random stratified sample of (N=130) lawyers. Results indicated that elderly lawyers are able to reduce work stress by control over the quantity of work, focus, and client selection. (Author/RC)

  14. Parental Family Stress during Pregnancy and Cognitive Functioning in Early Childhood: The Generation R Study

    ERIC Educational Resources Information Center

    Henrichs, Jens; Schenk, Jacqueline J.; Kok, Rianne; Ftitache, Bouchra; Schmidt, Henk G.; Hofman, Albert; Jaddoe, Vincent W. V.; Verhulst, Frank C.; Tiemeier, Henning

    2011-01-01

    We investigated whether parental family stress during pregnancy is associated with cognitive functioning in early childhood in a population-based cohort (n = 3139). Family stress was assessed using the Family Assessment Device at the 20th week of pregnancy and was reported by mothers and fathers. Mothers completed the MacArthur Communicative…

  15. Functional Play at 2 Years of Age: Effects of Prenatal Maternal Stress

    ERIC Educational Resources Information Center

    Laplante, David P.; Zelazo, Philip R.; Brunet, Alain; King, Suzanne

    2007-01-01

    Toddler toy play evolves in a predictable manner and provides a valid, nonverbal measure of cognitive function unbiased by social behaviors. Research on prenatal maternal stress (PNMS) indicates that exposure to stress in utero results in developmental deficits. We hypothesized that children exposed to high objective PNMS from a natural disaster…

  16. Selenium and vitamin E together improve intestinal epithelial barrier function and alleviate oxidative stress in heat-stressed pigs.

    PubMed

    Liu, Fan; Cottrell, Jeremy J; Furness, John B; Rivera, Leni R; Kelly, Fletcher W; Wijesiriwardana, Udani; Pustovit, Ruslan V; Fothergill, Linda J; Bravo, David M; Celi, Pietro; Leury, Brian J; Gabler, Nicholas K; Dunshea, Frank R

    2016-07-01

    glutathione peroxidase (GPX) activity and an increased glutathione disulfide (GSSG)-to-glutathione (GSH) ratio (both P < 0.05). With increasing dosage of Se and VE, GPX-2 mRNA (P = 0.003) and GPX activity (P = 0.049) increased linearly, the GSSG:GSH ratio decreased linearly (P = 0.037), and the impacts of heat stress on intestinal barrier function were reduced (P < 0.05 for both transepithelial electrical resistance and FD4 permeability). In conclusion, in pigs an increase of dietary Se and VE mitigated the impacts of heat stress on intestinal barrier integrity, associated with a reduction in oxidative stress. PMID:27064134

  17. On residual stresses and homeostasis: an elastic theory of functional adaptation in living matter

    NASA Astrophysics Data System (ADS)

    Ciarletta, P.; Destrade, M.; Gower, A. L.

    2016-04-01

    Living matter can functionally adapt to external physical factors by developing internal tensions, easily revealed by cutting experiments. Nonetheless, residual stresses intrinsically have a complex spatial distribution, and destructive techniques cannot be used to identify a natural stress-free configuration. This work proposes a novel elastic theory of pre-stressed materials. Imposing physical compatibility and symmetry arguments, we define a new class of free energies explicitly depending on the internal stresses. This theory is finally applied to the study of arterial remodelling, proving its potential for the non-destructive determination of the residual tensions within biological materials.

  18. On residual stresses and homeostasis: an elastic theory of functional adaptation in living matter.

    PubMed

    Ciarletta, P; Destrade, M; Gower, A L

    2016-01-01

    Living matter can functionally adapt to external physical factors by developing internal tensions, easily revealed by cutting experiments. Nonetheless, residual stresses intrinsically have a complex spatial distribution, and destructive techniques cannot be used to identify a natural stress-free configuration. This work proposes a novel elastic theory of pre-stressed materials. Imposing physical compatibility and symmetry arguments, we define a new class of free energies explicitly depending on the internal stresses. This theory is finally applied to the study of arterial remodelling, proving its potential for the non-destructive determination of the residual tensions within biological materials. PMID:27113413

  19. On residual stresses and homeostasis: an elastic theory of functional adaptation in living matter

    PubMed Central

    Ciarletta, P.; Destrade, M.; Gower, A. L.

    2016-01-01

    Living matter can functionally adapt to external physical factors by developing internal tensions, easily revealed by cutting experiments. Nonetheless, residual stresses intrinsically have a complex spatial distribution, and destructive techniques cannot be used to identify a natural stress-free configuration. This work proposes a novel elastic theory of pre-stressed materials. Imposing physical compatibility and symmetry arguments, we define a new class of free energies explicitly depending on the internal stresses. This theory is finally applied to the study of arterial remodelling, proving its potential for the non-destructive determination of the residual tensions within biological materials. PMID:27113413

  20. Yeast functional screen to identify genetic determinants capable of conferring abiotic stress tolerance in Jatropha curcas

    PubMed Central

    2010-01-01

    Background Environmentally inflicted stresses such as salinity and drought limit the plant productivity both in natural and agricultural system. Increasing emphasis has been directed to molecular breeding strategies to enhance the intrinsic ability of plant to survive stress conditions. Functional screens in microorganisms with heterologous genes are a rapid, effective and powerful tool to identify stress tolerant genes in plants. Jatropha curcas (Physic nut) has been identified as a potential source of biodiesel plant. In order to improve its productivity under stress conditions to benefit commercial plantations, we initiated prospecting of novel genes expressed during stress in J. curcas that can be utilized to enhance stress tolerance ability of plant. Results To identify genes expressed during salt tolerance, cDNA expression libraries were constructed from salt-stressed roots of J. curcas, regulated under the control of the yeast GAL1 system. Using a replica based screening, twenty thousand yeast transformants were screened to identify transformants expressing heterologous gene sequences from J. curcas with enhanced ability to tolerate stress. From the screen we obtained 32 full length genes from J. curcas [GenBank accession numbers FJ489601-FJ489611, FJ619041-FJ619057 and FJ623457-FJ623460] that can confer abiotic stress tolerance. As a part of this screen, we optimized conditions for salt stress in J. curcas, defined parameters for salt stress in yeast, as well as isolated three salt hypersensitive yeast strains shs-2, shs-6 and shs-8 generated through a process of random mutagenesis, and exhibited growth retardation beyond 750 mM NaCl. Further, we demonstrated complementation of the salt sensitive phenotypes in the shs mutants, and analyzed the expression patterns for selected J. curcas genes obtained from the screen in both leaf and root tissues after salt stress treatments. Conclusions The approach described in this report provides a rapid and universal

  1. The Relationship between Stress, Fatigue, and Cognitive Functioning

    ERIC Educational Resources Information Center

    Palmer, Laura K.; Economou, Peter; Cruz, Daniel; Abraham-Cook, Shannon; Huntington, Jodi S.; Maris, Marika; Makhija, Nita; Welsh, Toni; Maley, Larissa

    2014-01-01

    There is a plethora of research suggesting that daily stressors and fatigue can have a significant effect on learning and various cognitive functions in young adults. Little is known, however, about how these effects impact learning and other neurocognitive functions in students with learning challenges when compared to their counterparts without…

  2. The Relationship between Stress, Fatigue, and Cognitive Functioning

    ERIC Educational Resources Information Center

    Palmer, Laura K.

    2013-01-01

    There is a plethora of research suggesting that daily stressors and fatigue can have a significant effect on learning and various cognitive functions in young adults. Little is known, however, about how these effects impact learning and other neurocognitive functions in students with learning challenges when compared to their counterparts without…

  3. Stress, Cortisol, and B-Lymphocytes: A Novel Approach to Understanding Academic Stress and Immune Function

    PubMed Central

    McGregor, Bonnie A; Murphy, Karly Mary; Albano, Denise L; Ceballos, Rachel M

    2016-01-01

    Animal and human in vitro models suggest that stress-related B lymphocyte decrements are due to high levels of glucocorticoids which cause apoptosis of pre-B-cells as they emerge from the bone marrow. The present study sought to explore the relationships among distress, salivary cortisol and human B lymphocytes in vivo. Distress (perceived stress, negative affect, depressive symptoms), lymphocyte phenotype, and salivary cortisol were assessed among first year graduate students (n=22) and a community control sample (n= 30) at the start of classes in the fall and the week immediately before spring preliminary exams. Compared to controls, students reported greater distress on all measures at each time point except baseline perceived stress. Hierarchical linear regression with necessary control variables was used to assess the effect of student status on the three measures of distress, the four measures of lymphocyte phenotype, and cortisol AUC and CAR over time (T1-T2). Student status was associated with a significant decrease in CD19+ B lymphocytes and flattened cortisol awakening response (CAR). Change in CAR was associated with the decrease in CD19+ B lymphocytes. Results indicated that there are significant associations among student status, flattening of CAR, and decrements in CD19+ lymphocytes. PMID:26644211

  4. Maternal hydroxytyrosol administration improves neurogenesis and cognitive function in prenatally stressed offspring.

    PubMed

    Zheng, Adi; Li, Hao; Cao, Ke; Xu, Jie; Zou, Xuan; Li, Yuan; Chen, Cong; Liu, Jiankang; Feng, Zhihui

    2015-02-01

    Prenatal stress is known to induce emotional and cognitive dysfunction in the offspring of both humans and experimental animals. Hydroxytyrosol (HT), a major polyphenol in olive oil with reported ability modulating oxidative stress and mitochondrial function, was performed to investigate its preventive effect on prenatal stress-induced behavioral and molecular alterations in offspring. Rats were exposed to restraint stress on days 14-20 of pregnancy. HT was given at doses of 10 and 50 mg/kg/day. The spontaneous alternation performance and Morris water maze confirmed the impaired learning capacity and memory performance induced by prenatal stress in both male and female offspring, and these effects were markedly restored in the HT supplement groups. Through tissue analysis of the hippocampi of male offspring, we found that the stress-induced downregulation of neural proteins, including BDNF, GAP43, synaptophysin, NMDAR1, NMDANR2A and NMDANR2B, was prevented by HT. Prenatal stress-induced low expression of glucocorticoid receptor was also increased by HT, although basal fetal serum corticosterone levels were not different among the four groups. Oxidative stress and mitochondrial dysfunction in prenatally stressed rats were confirmed with changes in protein oxidation, SOD activity, the expression of mitochondrial complexes and mitochondrial DNA copy number. Meanwhile, HT significantly increased transcription factors FOXO1 and FOXO3, as well as phase II enzyme-related proteins, including Nrf2 and HO-1, which may contribute to the decreased oxidative stress and increased mitochondrial function shown with HT supplementation. Taken together, these findings suggest that HT is an efficient maternal nutrient protecting neurogenesis and cognitive function in prenatally stressed offspring. PMID:25442671

  5. Functional and Structural Remodeling of Glutamate Synapses in Prefrontal and Frontal Cortex Induced by Behavioral Stress

    PubMed Central

    Musazzi, Laura; Treccani, Giulia; Popoli, Maurizio

    2015-01-01

    Increasing evidence has shown that the pathophysiology of neuropsychiatric disorders, including mood disorders, is associated with abnormal function and regulation of the glutamatergic system. Consistently, preclinical studies on stress-based animal models of pathology showed that glucocorticoids and stress exert crucial effects on neuronal excitability and function, especially in cortical and limbic areas. In prefrontal and frontal cortex, acute stress was shown to induce enhancement of glutamate release/transmission dependent on activation of corticosterone receptors. Although the mechanisms whereby stress affects glutamate transmission have not yet been fully understood, it was shown that synaptic, non-genomic action of corticosterone is required to increase the readily releasable pool of glutamate vesicles, but is not sufficient to enhance transmission in prefrontal and frontal cortex. Slower, partly genomic mechanisms are probably necessary for the enhancement of glutamate transmission induced by stress. Combined evidence has suggested that the changes in glutamate release and transmission are responsible for the dendritic remodeling and morphological changes induced by stress and it has been argued that sustained alterations of glutamate transmission may play a key role in the long-term structural/functional changes associated with mood disorders in patients. Intriguingly, modifications of the glutamatergic system induced by stress in the prefrontal cortex seem to be biphasic. Indeed, while the fast response to stress suggests an enhancement in the number of excitatory synapses, synaptic transmission and working memory, long-term adaptive changes – including those consequent to chronic stress – induce opposite effects. Better knowledge of the cellular effectors involved in this biphasic effect of stress may be useful to understand the pathophysiology of stress-related disorders, and open new paths for the development of therapeutic approaches. PMID

  6. Effect of Mindfulness Meditation on Perceived Stress Scores and Autonomic Function Tests of Pregnant Indian Women

    PubMed Central

    Jain, Reena; Kohli, Sangeeta; Batra, Swaraj

    2016-01-01

    Introduction Various pregnancy complications like hypertension, preeclampsia have been strongly correlated with maternal stress. One of the connecting links between pregnancy complications and maternal stress is mind-body intervention which can be part of Complementary and Alternative Medicine (CAM). Biologic measures of stress during pregnancy may get reduced by such interventions. Aim To evaluate the effect of Mindfulness meditation on perceived stress scores and autonomic function tests of pregnant Indian women. Materials and Methods Pregnant Indian women of 12 weeks gestation were randomised to two treatment groups: Test group with Mindfulness meditation and control group with their usual obstetric care. The effect of Mindfulness meditation on perceived stress scores and cardiac sympathetic functions and parasympathetic functions (Heart rate variation with respiration, lying to standing ratio, standing to lying ratio and respiratory rate) were evaluated on pregnant Indian women. Results There was a significant decrease in perceived stress scores, a significant decrease of blood pressure response to cold pressor test and a significant increase in heart rate variability in the test group (p< 0.05, significant) which indicates that mindfulness meditation is a powerful modulator of the sympathetic nervous system and can thereby reduce the day-to-day perceived stress in pregnant women. Conclusion The results of this study suggest that mindfulness meditation improves parasympathetic functions in pregnant women and is a powerful modulator of the sympathetic nervous system during pregnancy. PMID:27190795

  7. Cardiovascular function during sustained +G/z/ stress

    NASA Technical Reports Server (NTRS)

    Erickson, H. H.; Sandler, H.; Stone, H. L.

    1976-01-01

    The development of aerospace systems capable of very high levels of positive vertical accelerators stress has created a need for a better understanding of the cardiovascular responses to acceleration. Using a canine model, the heart and cardiovascular system were instrumented to continuously measure coronary blood flow, cardiac output, left ventricular and aortic root pressure, and oxygen saturation in the aorta, coronary sinus, and right ventricle. The animals were exposed to acceleration profiles up to +6 G, 120 s at peak G; a seatback angle of 45 deg was simulated in some experiments. Radiopaque contrast medium was injected to visualize the left ventricular chamber, coronary vasculature, aorta, and branches of the aorta. The results suggest mechanisms responsible for arrhythmias which may occur, and subendocardial hemorrhage which has been reported in other animals.

  8. Mindfulness meditation training alters stress-related amygdala resting state functional connectivity: a randomized controlled trial.

    PubMed

    Taren, Adrienne A; Gianaros, Peter J; Greco, Carol M; Lindsay, Emily K; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K; Ferris, Jennifer L; Julson, Erica; Marsland, Anna L; Bursley, James K; Ramsburg, Jared; Creswell, J David

    2015-12-01

    Recent studies indicate that mindfulness meditation training interventions reduce stress and improve stress-related health outcomes, but the neural pathways for these effects are unknown. The present research evaluates whether mindfulness meditation training alters resting state functional connectivity (rsFC) of the amygdala, a region known to coordinate stress processing and physiological stress responses. We show in an initial discovery study that higher perceived stress over the past month is associated with greater bilateral amygdala-subgenual anterior cingulate cortex (sgACC) rsFC in a sample of community adults (n = 130). A follow-up, single-blind randomized controlled trial shows that a 3-day intensive mindfulness meditation training intervention (relative to a well-matched 3-day relaxation training intervention without a mindfulness component) reduced right amygdala-sgACC rsFC in a sample of stressed unemployed community adults (n = 35). Although stress may increase amygdala-sgACC rsFC, brief training in mindfulness meditation could reverse these effects. This work provides an initial indication that mindfulness meditation training promotes functional neuroplastic changes, suggesting an amygdala-sgACC pathway for stress reduction effects. PMID:26048176

  9. Stress chaperone GRP-78 functions in mineralized matrix formation.

    PubMed

    Ravindran, Sriram; Gao, Qi; Ramachandran, Amsaveni; Blond, Sylvie; Predescu, Sanda A; George, Anne

    2011-03-18

    Mineralized matrix formation is a well orchestrated event requiring several players. Glucose-regulated protein-78 (GRP-78) is an endoplasmic reticulum chaperone protein that has been implicated in functional roles ranging from involvement in cancer biology to serving as a receptor for viruses. In the present study we explored the role of GRP-78 in mineralized matrix formation. Differential expression of GRP-78 mRNA and protein was observed upon in vitro differentiation of primary mouse calvarial cells. An interesting observation was that GRP-78 was identified in the secretome of these cells and in the bone matrix, suggesting an extracellular function during matrix formation. In vitro nucleation experiments under physiological concentrations of calcium and phosphate ions indicated that GRP-78 can induce the formation of calcium phosphate polymorphs by itself, when bound to immobilized type I collagen and on demineralized collagen wafers. We provide evidence that GRP-78 can bind to DMP1 and type I collagen independent of each other in a simulated extracellular environment. Furthermore, we demonstrate the cell surface localization of GRP-78 and provide evidence that it functions as a receptor for DMP1 endocytosis in pre-osteoblasts and primary calvarial cells. Overall, this study represents a paradigm shift in the biological function of GRP-78. PMID:21239500

  10. Stress Chaperone GRP-78 Functions in Mineralized Matrix Formation*

    PubMed Central

    Ravindran, Sriram; Gao, Qi; Ramachandran, Amsaveni; Blond, Sylvie; Predescu, Sanda A.; George, Anne

    2011-01-01

    Mineralized matrix formation is a well orchestrated event requiring several players. Glucose-regulated protein-78 (GRP-78) is an endoplasmic reticulum chaperone protein that has been implicated in functional roles ranging from involvement in cancer biology to serving as a receptor for viruses. In the present study we explored the role of GRP-78 in mineralized matrix formation. Differential expression of GRP-78 mRNA and protein was observed upon in vitro differentiation of primary mouse calvarial cells. An interesting observation was that GRP-78 was identified in the secretome of these cells and in the bone matrix, suggesting an extracellular function during matrix formation. In vitro nucleation experiments under physiological concentrations of calcium and phosphate ions indicated that GRP-78 can induce the formation of calcium phosphate polymorphs by itself, when bound to immobilized type I collagen and on demineralized collagen wafers. We provide evidence that GRP-78 can bind to DMP1 and type I collagen independent of each other in a simulated extracellular environment. Furthermore, we demonstrate the cell surface localization of GRP-78 and provide evidence that it functions as a receptor for DMP1 endocytosis in pre-osteoblasts and primary calvarial cells. Overall, this study represents a paradigm shift in the biological function of GRP-78. PMID:21239500

  11. Real-time sensor mapping display for airborne imaging sensor test with the adaptive infrared imaging spectroradiometer (AIRIS)

    NASA Astrophysics Data System (ADS)

    Burton, Megan M.; Cruger, William E.; Gittins, Christopher; Kindle, Harry; Ricks, Timothy P.

    2005-11-01

    Captive flight testing (CFT) of sensors and seekers requires accurate data collection and display for sensor performance evaluation. The U.S. Army Redstone Technical Test Center (RTTC), in support of the U.S. Army Edgewood Chemical Biological Center (ECBC), has developed a data collection suite to facilitate airborne test of hyperspectral chemical/biological sensors. The data collection suite combines global positioning system (GPS) tracking, inertial measurement unit (IMU) data, accurate timing streams, and other test scenario information. This data collection suite also contains an advanced real-time display of aircraft and sensor field-of-view information. The latest evolution of this system has been used in support of the Adaptive InfraRed Imaging Spectroradiometer (AIRIS), currently under development by Physical Sciences Incorporated for ECBC. For this test, images from the AIRIS sensor were overlaid on a digitized background of the test area, with latencies of 1 second or less. Detects of surrogate chemicals were displayed and geo-referenced. Video overlay was accurate and reliable. This software suite offers great versatility in the display of imaging sensor data; support of future tests with the AIRIS sensor are planned as the system evolves.

  12. Fibroblast Growth Factor 8 Deficiency Compromises the Functional Response of the Serotonergic System to Stress

    PubMed Central

    Brooks, Leah R.; Pals, Heide L.; Enix, Courtney L.; Woolaver, Rachel A.; Paul, Evan D.; Lowry, Christopher A.; Tsai, Pei-San

    2014-01-01

    Functionally heterogeneous populations of serotonergic neurons, located within the dorsal raphe nucleus (DR), play a role in stress-related behaviors and neuropsychiatric illnesses such as anxiety and depression. Abnormal development of these neurons may permanently alter their structure and connections, making the organism more susceptible to anxiety-related disorders. A factor that critically regulates the development of serotonergic neurons is fibroblast growth factor 8 (Fgf8). In this study, we used acute restraint stress followed by behavioral testing to examine whether Fgf8 signaling during development is important for establishing functional stress- and anxiety-related DR neurocircuits in adulthood. Wild-type and heterozygous male mice globally hypomorphic for Fgf8 were exposed to acute restraint stress and then tested for anxiety-like behavior on the elevated plus-maze. Further, we measured c-Fos immunostaining as a marker of serotonergic neuronal activation and tissue 5-hydroxyindoleacetic acid concentrations as a marker of serotonin functional output. Results showed that Fgf8 hypomorphs exhibited 1) an exaggerated response of DR anxiety-promoting circuits and 2) a blunted response of a DR panic-inhibiting circuit to stress, effects that together were associated with increased baseline anxiety-like behavior. Overall, our results provide a neural substrate upon which Fgf8 deficiency could affect stress response and support the hypothesis that developmental disruptions of serotonergic neurons affect their postnatal functional integrity. PMID:24992493

  13. Neighborhood functions alter unbalanced facilitation on a stress gradient in an alpine treeline simulation

    NASA Astrophysics Data System (ADS)

    Malanson, G. P.; Resler, L. M.

    2014-12-01

    The stress-gradient hypothesis states that individual and species competitive and facilitative effects change in relative importance or intensity along environmental gradients of stress. The importance of the number of facilitators in the neighborhood of a potential beneficiary has not been explored. Evenly distributed and stress-correlated facilitation and the increase in the intensity of facilitation with neighbors as linear, logarithmic, and unimodal functions is simulated for two species such as Pinus albicaulis and Abies lasiocarpa. The mutualism is unbalanced in that the establishment of one species is enhanced by neighbors more than the other. Compared to no facilitation or evenly distributed facilitation, the stress gradient produces more edges in the spatially advancing population, more overall intensity of facilitation, and more individuals further advanced into the area of higher stress; the more enhanced species has increased population relative to the other - to the point where they are equal. Among three neighborhood functions, little difference exists in outcomes between the linear and logarithmic functions, but the unimodal function, which shifts peak facilitation intensity to fewer neighbors, increases the above state variables more than the differences between the even and stress gradient facilitation scenarios. The unbalanced mutualism may be important at treeline ecotones where the spatial pattern becomes central to facilitation.

  14. Effects of stress on immune function: the good, the bad, and the beautiful.

    PubMed

    Dhabhar, Firdaus S

    2014-05-01

    Although the concept of stress has earned a bad reputation, it is important to recognize that the adaptive purpose of a physiological stress response is to promote survival during fight or flight. While long-term stress is generally harmful, short-term stress can be protective as it prepares the organism to deal with challenges. This review discusses the immune effects of biological stress responses that can be induced by psychological, physiological, or physical (including exercise) stressors. We have proposed that short-term stress is one of the nature's fundamental but under-appreciated survival mechanisms that could be clinically harnessed to enhance immunoprotection. Short-term (i.e., lasting for minutes to hours) stress experienced during immune activation enhances innate/primary and adaptive/secondary immune responses. Mechanisms of immuno-enhancement include changes in dendritic cell, neutrophil, macrophage, and lymphocyte trafficking, maturation, and function as well as local and systemic production of cytokines. In contrast, long-term stress suppresses or dysregulates innate and adaptive immune responses by altering the Type 1-Type 2 cytokine balance, inducing low-grade chronic inflammation, and suppressing numbers, trafficking, and function of immunoprotective cells. Chronic stress may also increase susceptibility to some types of cancer by suppressing Type 1 cytokines and protective T cells and increasing regulatory/suppressor T cell function. Here, we classify immune responses as being protective, pathological, or regulatory, and discuss "good" versus "bad" effects of stress on health. Thus, short-term stress can enhance the acquisition and/or expression of immunoprotective (wound healing, vaccination, anti-infectious agent, anti-tumor) or immuno-pathological (pro-inflammatory, autoimmune) responses. In contrast, chronic stress can suppress protective immune responses and/or exacerbate pathological immune responses. Studies such as the ones discussed

  15. Circadian Clocks and the Interaction between Stress Axis and Adipose Function

    PubMed Central

    Kolbe, Isa; Dumbell, Rebecca

    2015-01-01

    Many physiological processes and most endocrine functions show fluctuations over the course of the day. These so-called circadian rhythms are governed by an endogenous network of cellular clocks and serve as an adaptation to daily and, thus, predictable changes in the organism's environment. Circadian clocks have been described in several tissues of the stress axis and in adipose cells where they regulate the rhythmic and stimulated release of stress hormones, such as glucocorticoids, and various adipokine factors. Recent work suggests that both adipose and stress axis clock systems reciprocally influence each other and adrenal-adipose rhythms may be key players in the development and therapy of metabolic disorders. In this review, we summarize our current understanding of adrenal and adipose tissue rhythms and clocks and how they might interact to regulate energy homoeostasis and stress responses under physiological conditions. Potential chronotherapeutic strategies for the treatment of metabolic and stress disorders are discussed. PMID:26000016

  16. Childhood poverty and stress reactivity are associated with aberrant functional connectivity in default mode network.

    PubMed

    Sripada, Rebecca K; Swain, James E; Evans, Gary W; Welsh, Robert C; Liberzon, Israel

    2014-08-01

    Convergent research suggests that childhood poverty is associated with perturbation in the stress response system. This might extend to aberrations in the connectivity of large-scale brain networks, which subserve key cognitive and emotional functions. Resting-state brain activity was measured in adults with a documented history of childhood poverty (n=26) and matched controls from middle-income families (n=26). Participants also underwent a standard laboratory social stress test and provided saliva samples for cortisol assay. Childhood poverty was associated with reduced default mode network (DMN) connectivity. This, in turn, was associated with higher cortisol levels in anticipation of social stress. These results suggest a possible brain basis for exaggerated stress sensitivity in low-income individuals. Alterations in DMN may be associated with less efficient cognitive processing or greater risk for development of stress-related psychopathology among individuals who experienced the adversity of chronic childhood poverty. PMID:24675708

  17. Plume Aerosol Size Distribution Modeling and Comparisons to PrAIRie2005 Field Study Data

    NASA Astrophysics Data System (ADS)

    Cho, S.; Liggio, J.; Makar, P.; Li, S.; Racinthe, J.

    2006-12-01

    As part of the analysis phase of the PrAIRie2005 field study, the effects of different Edmonton-area emission sources on local air-quality are being examined. Four large coal-fired power-plants are located to the West of the city. Here, the effects of these power-plants on urban and regional air-quality will be examined, using both plume and regional air-quality models. During the last few decades, coal-fired power plants have been found to be as a major source of pollution, affecting public-health. According to NACEC (North American Commission for Environmental Corporation, 2001)'s report, 46 of the top 50 air polluters in North America were power plants. The importance of such sources has resulted in several attempts to improve understanding of the basic formation mechanisms of plume particulate matter. Sulphur dioxide contributes to acidifying emissions and to the production of secondary acidic aerosols that have been linked to a number of serious human health problems, acid rain and visibility (Seinfeld and Pandis, 1998; Hidy, 1984; Wilson and McMurray, 1981). Primary particulate matter originating directly from coal-fired power plants may also increase secondary particulate mass by providing a surface for sulphuric acid absorption . Environment Canada's PrAIRie2005 field study between August 12th and September 7th, 2005 included overflights and downwind measurements near the Edmonton powerplants (Wabamun, Sundance, Keephills and Genesee). The data collected consisted of particle size distributions, ozone, NOX, total mass and the chemical composition of fine particles. In order to investigate and improve our understanding of the formation mechanisms and physical properties of power-plant-generated aerosols in the Edmonton area, the Plume Aerosol Microphysical (PAM) model has been employed. This model accounts for gas-phase chemistry, aerosol microphysical processes (i.e. homogeneous/heterogeneous nucleation, condensation/evaporation and coagulation) and

  18. Endoplasmic Reticulum Stress in Intestinal Epithelial Cell Function and Inflammatory Bowel Disease

    PubMed Central

    Luo, Katherine; Cao, Stewart Siyan

    2015-01-01

    In eukaryotic cells, perturbation of protein folding homeostasis in the endoplasmic reticulum (ER) causes accumulation of unfolded and misfolded proteins in the ER lumen, which activates intracellular signaling pathways termed the unfolded protein response (UPR). Recent studies have linked ER stress and the UPR to inflammatory bowel disease (IBD). The microenvironment of the ER is affected by a myriad of intestinal luminal molecules, implicating ER stress and the UPR in proper maintenance of intestinal homeostasis. Several intestinal cell populations, including Paneth and goblet cells, require robust ER function for protein folding, maturation, and secretion. Prolonged ER stress and impaired UPR signaling may cause IBD through: (1) induction of intestinal epithelial cell apoptosis, (2) disruption of mucosal barrier function, and (3) induction of the proinflammatory response in the gut. Based on our increased understanding of ER stress in IBD, new pharmacological approaches can be developed to improve intestinal homeostasis by targeting ER protein-folding in the intestinal epithelial cells (IECs). PMID:25755668

  19. Similarity in the difference: changes in community functional features along natural and anthropogenic stress gradients.

    PubMed

    Gutiérrez-Cánovas, Cayetano; Sánchez-Fernández, David; Velasco, Josefa; Millan, Andrés; Bonada, Núria

    2015-09-01

    The effect of stressors on biodiversity can vary in relation to the degree to which biological communities have adapted over evolutionary time. We compared the responses of functional features of stream insect communities along chronic stress gradients with contrasting time persistence. Water salinity and land use intensification were used as examples of natural (long-term persistent) and anthropogenic (short-term persistent) stressors, respectively. A new trait-based approach was applied to quantify functional diversity components and functional redundancy within the same multidimensional space, using metrics at the taxon and community levels. We found similar functional responses along natural and anthropogenic stress gradients. In both cases, the mean taxon functional richness and functional similarity between taxa increased with stress, whereas community functional richness and functional redundancy decreased. Despite the differences in evolutionary persistence, both chronic stressors act as strong nonrandom environmental filters, producing convergent functional responses. These results can improve our ability to predict functional effects of novel stressors at ecoloiical and evolutionary scales. PMID:26594702

  20. Functional polymorphisms in the P2X7 receptor gene are associated with stress fracture injury.

    PubMed

    Varley, Ian; Greeves, Julie P; Sale, Craig; Friedman, Eitan; Moran, Daniel S; Yanovich, Ran; Wilson, Peter J; Gartland, Alison; Hughes, David C; Stellingwerff, Trent; Ranson, Craig; Fraser, William D; Gallagher, James A

    2016-03-01

    Military recruits and elite athletes are susceptible to stress fracture injuries. Genetic predisposition has been postulated to have a role in their development. The P2X7 receptor (P2X7R) gene, a key regulator of bone remodelling, is a genetic candidate that may contribute to stress fracture predisposition. The aim of this study is to evaluate the putative contribution of P2X7R to stress fracture injury in two separate cohorts, military personnel and elite athletes. In 210 Israeli Defense Forces (IDF) military conscripts, stress fracture injury was diagnosed (n = 43) based on symptoms and a positive bone scan. In a separate cohort of 518 elite athletes, self-reported medical imaging scan-certified stress fracture injuries were recorded (n = 125). Non-stress fracture controls were identified from these cohorts who had a normal bone scan or no history or symptoms of stress fracture injury. Study participants were genotyped for functional SNPs within the P2X7R gene using proprietary fluorescence-based competitive allele-specific PCR assay. Pearson's chi-squared (χ (2)) tests, corrected for multiple comparisons, were used to assess associations in genotype frequencies. The variant allele of P2X7R SNP rs3751143 (Glu496Ala-loss of function) was associated with stress fracture injury, whilst the variant allele of rs1718119 (Ala348Thr-gain of function) was associated with a reduced occurrence of stress fracture injury in military conscripts (P < 0.05). The association of the variant allele of rs3751143 with stress fractures was replicated in elite athletes (P < 0.05), whereas the variant allele of rs1718119 was also associated with reduced multiple stress fracture cases in elite athletes (P < 0.05). The association between independent P2X7R polymorphisms with stress fracture prevalence supports the role of a genetic predisposition in the development of stress fracture injury. PMID:26825304

  1. Density functional theory calculation of edge stresses in monolayer MoS2

    NASA Astrophysics Data System (ADS)

    Qi, Zenan; Cao, Penghui; Park, Harold S.

    2013-10-01

    We utilize density functional theory to calculate the edge energy and edge stress for monolayer MoS2 nanoribbons. In contrast to previous reports for graphene, for both armchair and zigzag chiralities, the edge stresses for MoS2 nanoribbons are found to be tensile, indicating that their lowest energy configuration is one of compression in which Mo-S bond lengths are shorter than those in a bulk, periodic MoS2 monolayer. The edge energy and edge stress is found to converge for both chiralities for nanoribbon widths larger than about 1 nm.

  2. Evidence for Mini-Magnetospheres at four Lunar Magnetic Anomalies: Reiner-Gamma, Airy, Descartes and Crozier

    NASA Astrophysics Data System (ADS)

    Nayak, M.; Garrick-Bethell, I.; Hemingway, D.

    2014-12-01

    Lunar swirls are enigmatic high-albedo surface markings co-located with magnetic anomalies. The existence of mini-magnetospheres has been proposed as a formation mechanism, making small-scale magnetic field interactions with the solar wind of interest. Using data from the Lunar Prospector, Clementine, and Advanced Composition Explorer missions, we develop three metrics for the identification of mini-magnetospheres: 1) presence of coherent magnetism at low altitude for magnetic field measurements taken in the solar wind; 2) directional field distortions that are correlated with changes in incident solar wind azimuth; 3) intensification of total field strength. These metrics are applied to four lunar magnetic anomalies with various reflectances and magnetic field strengths, ranging from fully developed swirls (Reiner-Gamma, Airy) to diffuse albedo patches which may or may not be swirls (Descartes, Crozier). Specifically, we compare magnetic field measurements in the solar wind to source magnetization models constructed from observations in the lunar wake and Earth's magnetotail. By applying these criteria, we confirm previous findings of magnetosphere-like phenomena at Reiner-Gamma. We also find evidence of these phenomena at Descartes and Airy, and propose that mini-magnetospheres may exist here. At Airy, very large upwind distortions are observed, comparable to the length scale of the anomaly itself. At Reiner-Gamma and Descartes, this distortion is significantly smaller, yet the average field strengths are higher, implying that the scale of distortion is linked to the anomaly's field strength. Interestingly, at Crozier, the weakest anomaly considered, we do not observe this distortion. However, we do observe evidence of field intensification at high solar wind pressures (16 nPa). While Descartes and Reiner-Gamma are among the strongest anomalies on the Moon, and both exhibit magnetospheric properties, only Reiner-Gamma shows a well-developed swirl pattern

  3. Hypothesis: NDL proteins function in stress responses by regulating microtubule organization

    PubMed Central

    Khatri, Nisha; Mudgil, Yashwanti

    2015-01-01

    N-MYC DOWNREGULATED-LIKE proteins (NDL), members of the alpha/beta hydrolase superfamily were recently rediscovered as interactors of G-protein signaling in Arabidopsis thaliana. Although the precise molecular function of NDL proteins is still elusive, in animals these proteins play protective role in hypoxia and expression is induced by hypoxia and nickel, indicating role in stress. Homology of NDL1 with animal counterpart N-MYC DOWNREGULATED GENE (NDRG) suggests similar functions in animals and plants. It is well established that stress responses leads to the microtubule depolymerization and reorganization which is crucial for stress tolerance. NDRG is a microtubule-associated protein which mediates the microtubule organization in animals by causing acetylation and increases the stability of α-tubulin. As NDL1 is highly homologous to NDRG, involvement of NDL1 in the microtubule organization during plant stress can also be expected. Discovery of interaction of NDL with protein kinesin light chain- related 1, enodomembrane family protein 70, syntaxin-23, tubulin alpha-2 chain, as a part of G protein interactome initiative encourages us to postulate microtubule stabilizing functions for NDL family in plants. Our search for NDL interactors in G protein interactome also predicts the role of NDL proteins in abiotic stress tolerance management. Based on published report in animals and predicted interacting partners for NDL in G protein interactome lead us to hypothesize involvement of NDL in the microtubule organization during abiotic stress management in plants. PMID:26583023

  4. Hypothesis: NDL proteins function in stress responses by regulating microtubule organization.

    PubMed

    Khatri, Nisha; Mudgil, Yashwanti

    2015-01-01

    N-MYC DOWNREGULATED-LIKE proteins (NDL), members of the alpha/beta hydrolase superfamily were recently rediscovered as interactors of G-protein signaling in Arabidopsis thaliana. Although the precise molecular function of NDL proteins is still elusive, in animals these proteins play protective role in hypoxia and expression is induced by hypoxia and nickel, indicating role in stress. Homology of NDL1 with animal counterpart N-MYC DOWNREGULATED GENE (NDRG) suggests similar functions in animals and plants. It is well established that stress responses leads to the microtubule depolymerization and reorganization which is crucial for stress tolerance. NDRG is a microtubule-associated protein which mediates the microtubule organization in animals by causing acetylation and increases the stability of α-tubulin. As NDL1 is highly homologous to NDRG, involvement of NDL1 in the microtubule organization during plant stress can also be expected. Discovery of interaction of NDL with protein kinesin light chain- related 1, enodomembrane family protein 70, syntaxin-23, tubulin alpha-2 chain, as a part of G protein interactome initiative encourages us to postulate microtubule stabilizing functions for NDL family in plants. Our search for NDL interactors in G protein interactome also predicts the role of NDL proteins in abiotic stress tolerance management. Based on published report in animals and predicted interacting partners for NDL in G protein interactome lead us to hypothesize involvement of NDL in the microtubule organization during abiotic stress management in plants. PMID:26583023

  5. The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

    NASA Astrophysics Data System (ADS)

    Kim, Dong Hyun; Gratchev, Ivan; Hein, Maw; Balasubramaniam, Arumugam

    2016-08-01

    This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton's empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

  6. Moderators and mediators of the stress-aggression relationship: executive function and state anger.

    PubMed

    Sprague, Jenessa; Verona, Edelyn; Kalkhoff, Will; Kilmer, Ashley

    2011-02-01

    The present study examined the effects of executive function (i.e., EF) and anger/hostility on the relationship between stress (across individual stress domains, as well as at the aggregate level) and aggression. Two independent groups of participants-a college sample and a low-income community sample-were administered a battery of self-report measures concerning the subjective experience of stress, aggressive behaviors, and feelings of state anger and hostility in the last month, along with a battery of well-validated neuropsychological tests of EF. Across both samples, the stress domains that demonstrated the strongest associations with aggression were those involving chronic strains of daily living (e.g., job, financial, health) versus interpersonal stressors (e.g., family, romantic). In the community sample, analyses also revealed a significant interaction between perceived stress (aggregated across domains) and EF in predicting aggressive behavior. Specifically, participants with relatively low EF abilities, across different EF processes, showed a stronger relationship between different domains of stress and aggression in the last month. Similar effects were demonstrated in the college sample, although the interaction was not significant. In both samples, experiences of anger and hostility in the last month mediated the relationship between perceived stress (aggregate) and aggressive behavior among those low, but not high, in EF. These findings highlight the importance of higher-order cognitive processes in regulating appropriate affective and behavioral responses across different types of individuals, particularly among those experiencing high levels of stress. PMID:21401226

  7. Stress

    MedlinePlus

    ... sudden negative change, such as losing a job, divorce, or illness Traumatic stress, which happens when you ... stress, so you can avoid more serious health effects. NIH: National Institute of Mental Health

  8. Functions of heat shock transcription factors involved in response to photooxidative stresses in Arabidopsis.

    PubMed

    Yabuta, Yukinori

    2016-07-01

    Because plants are continually exposed to various environmental stresses, they possess numerous transcription factors that regulate metabolism to adapt and acclimate to those conditions. To clarify the gene regulation systems activated in response to photooxidative stress, we isolated 76 high light and heat shock stress-inducible genes, including heat shock transcription factor (Hsf) A2 from Arabidopsis. Unlike yeast or animals, more than 20 genes encoding putative Hsfs are present in the genomes of higher plants, and they are categorized into three classes based on their structural characterization. However, the multiplicity of Hsfs in plants remains unknown. Furthermore, the individual functions of Hsfs are also largely unknown because of their genetic redundancy. Recently, the developments of T-DNA insertion knockout mutant lines and chimeric repressor gene-silencing technology have provided effective tools for exploring the individual functions of Hsfs. This review describes the current knowledge on the individual functions and activation mechanisms of Hsfs. PMID:27095030

  9. Propagation properties of Airy-Gaussian vortex beams through the gradient-index medium.

    PubMed

    Zhao, Ruihuang; Deng, Fu; Yu, Weihao; Huang, Jiayao; Deng, Dongmei

    2016-06-01

    Propagation of Airy-Gaussian vortex (AiGV) beams through the gradient-index medium is investigated analytically and numerically with the transfer matrix method. Deriving the analytic expression of the AiGV beams based on the Huygens diffraction integral formula, we obtain the propagate path, intensity and phase distributions, and the Poynting vector of the first- and second-order AiGV beams, which propagate through the paraxial ABCD system. The ballistic trajectory is no longer conventional parabolic but trigonometric shapes in the gradient-index medium. Especially, the AiGV beams represent the singular behavior at the propagation path and the light intensity distribution. The phase distribution and the Poynting vector exhibit in reverse when the AiGV beams through the singularity. As the order increases, the main lobe of the AiGV beams is gradually overlapped by the vortex core. Further, the sidelobe weakens when the AiGV beams propagate nearly to the singularity. Additionally, the figure of the Poynting vector of the AiGV beams proves the direction of energy flow corresponding to the intensity distribution. The vortex of the second-order AiGV beams is larger, and the propagation velocity is faster than that of the first order. PMID:27409428

  10. Manipulation of Raman-induced frequency shift by use of asymmetric self-accelerating Airy pulse.

    PubMed

    Zhang, Lifu; Zhong, Haizhe; Li, Ying; Fan, Dianyuan

    2014-09-22

    We investigate the evolution of asymmetric self-accelerating finite energy Airy pulses (FEAP) in optical fibers with emphasis on the role of Raman scattering. We show that the Raman-induced frequency shift (RIFS) of soliton initiated by an asymmetric self-accelerating FEAP depends not only on the launched peak power but also on the truncation coefficient imposed on the asymmetric self-accelerating FEAP. We find that the RIFS of asymmetric self-accelerating FEAP increases with a decrease in the truncation coefficient, while the peak power and spectrum width of the outermost red shift of the shedding soliton spectrum are almost unchanged. The time and frequency shifts of the shedding soliton are found to be sensitive to the truncation coefficient when the truncation coefficient is in the range of 0 to 0.1. These excellent features would lead to the realization of a RIFS-based tunable light source by launching self-accelerating FEAP with different truncation coefficient into an optical fiber. PMID:25321729

  11. Perceived Stress and Change in Cognitive Function Among Adults Aged 65 and Older

    PubMed Central

    Aggarwal, Neelum T.; Wilson, Robert S.; Beck, Todd L.; Rajan, Kumar B.; Mendes de Leon, Carlos F.; Evans, Denis A.; Everson-Rose, Susan A.

    2014-01-01

    Objective Exposure to acute and chronic stress can affect learning and memory but most evidence comes from animal studies or clinical observations. Almost no population-based studies have investigated the relation of stress to cognition or changes in cognition over time. We examined whether higher levels of perceived stress were associated with accelerated decline in cognitive function in older blacks and whites from a community-based population sample. Methods Participants included 6,207 black and white adults (65.7% black, 63.3% women) from the Chicago Health and Aging project. Two to five in-home assessments were completed over an average of 6.8 years of follow up, and included sociodemographics, health behaviors, psychosocial measures, cognitive function tests, and health history. Perceived stress was measured by a 6-item scale, and a composite measure of four tests of cognition was used to determine cognitive function at each assessment. Results Mixed effects regression models showed that increasing levels of perceived stress were related to lower initial cognitive scores (B=-0.0379, SE=0.0025, p<.001) and a faster rate of cognitive decline (stress × time interaction: B=-0.0015, SE=0.0004, p<.001). Results were similar after adjusting for demographic variables, smoking, systolic blood pressure, body mass index, chronic medical conditions, and psychosocial factors and did not vary by race, sex, age or education. Conclusion Increasing levels of stress are independently associated with accelerated declines in cognitive function in black and white adults aged 65 and above. PMID:24367123

  12. Stress differentially impacts reserve pools and root exudation: implications for ecosystem functioning and carbon balance

    NASA Astrophysics Data System (ADS)

    Landhäusser, Simon; Karst, Justine; Wiley, Erin; Gaster, Jacob

    2016-04-01

    Environmental stress can influence carbon assimilation and the accumulation and distribution of carbon between growth, reserves, and exudation; however, it is unclear how these processes vary by different stress types. Partitioning of carbon to growth and reserves in plants might also vary between different organs. Roots reserves are of particular interest as they link the plant with the soil carbon cycle through exudation. Simple models of diffusion across concentration gradients predict the more C reserves in roots, the more C should be exuded from roots. However, the mechanisms underlying the accumulation and loss of C from roots may differ depending on the stress experienced by the plants. In a controlled study we tested whether different types of stresses (shade, cold soil, and drought) have differential effects on the distribution, abundance, and form (sugar vs. starch) of carbohydrates in seedlings, and whether these changes alone could explain differences in root exudation between stress types. Non-structural carbohydrate (NSC) concentration and pool sizes varied by stress type and between organs. Mass-specific C exudation increased with fine root sugar concentration; however, stress type affected exudation independently of reserve concentration. Seedlings exposed to cold soils exuded the most C on a per root mass basis followed by shade and drought. Through 13C labeling, we also found that depending on the stress type, aspen seedlings may be less able to control the loss of C to the soil compared with unstressed seedlings, resulting in more C leaked to the rhizosphere. The loss of C beyond that predicted by simple concentration gradients might have important implications for ecosystem functioning and carbon balance. If stressed plants lose proportionally more carbon to the soil, existing interactions between plants and soils may decouple under stress, and may include unexpected C fluxes between trees, soils and the atmosphere with a changing climate.

  13. Functional Changes in Littoral Macroinvertebrate Communities in Response to Watershed-Level Anthropogenic Stress

    PubMed Central

    Kovalenko, Katya E.; Brady, Valerie J.; Ciborowski, Jan J. H.; Ilyushkin, Sergey; Johnson, Lucinda B.

    2014-01-01

    Watershed-scale anthropogenic stressors have profound effects on aquatic communities. Although several functional traits of stream macroinvertebrates change predictably in response to land development and urbanization, little is known about macroinvertebrate functional responses in lakes. We assessed functional community structure, functional diversity (Rao’s quadratic entropy) and voltinism in macroinvertebrate communities sampled across the full gradient of anthropogenic stress in Laurentian Great Lakes coastal wetlands. Functional diversity and voltinism significantly decreased with increasing development, whereas agriculture had smaller or non-significant effects. Functional community structure was affected by watershed-scale development, as demonstrated by an ordination analysis followed by regression. Because functional community structure affects energy flow and ecosystem function, and functional diversity is known to have important implications for ecosystem resilience to further environmental change, these results highlight the necessity of finding ways to remediate or at least ameliorate these effects. PMID:25006811

  14. Functional changes in littoral macroinvertebrate communities in response to watershed-level anthropogenic stress.

    PubMed

    Kovalenko, Katya E; Brady, Valerie J; Ciborowski, Jan J H; Ilyushkin, Sergey; Johnson, Lucinda B

    2014-01-01

    Watershed-scale anthropogenic stressors have profound effects on aquatic communities. Although several functional traits of stream macroinvertebrates change predictably in response to land development and urbanization, little is known about macroinvertebrate functional responses in lakes. We assessed functional community structure, functional diversity (Rao's quadratic entropy) and voltinism in macroinvertebrate communities sampled across the full gradient of anthropogenic stress in Laurentian Great Lakes coastal wetlands. Functional diversity and voltinism significantly decreased with increasing development, whereas agriculture had smaller or non-significant effects. Functional community structure was affected by watershed-scale development, as demonstrated by an ordination analysis followed by regression. Because functional community structure affects energy flow and ecosystem function, and functional diversity is known to have important implications for ecosystem resilience to further environmental change, these results highlight the necessity of finding ways to remediate or at least ameliorate these effects. PMID:25006811

  15. Functional characterization of a Glycine soja Ca(2+)ATPase in salt-alkaline stress responses.

    PubMed

    Sun, Mingzhe; Jia, Bowei; Cui, Na; Wen, Yidong; Duanmu, Huizi; Yu, Qingyue; Xiao, Jialei; Sun, Xiaoli; Zhu, Yanming

    2016-03-01

    It is widely accepted that Ca(2+)ATPase family proteins play important roles in plant environmental stress responses. However, up to now, most researches are limited in the reference plants Arabidopsis and rice. The function of Ca(2+)ATPases from non-reference plants was rarely reported, especially its regulatory role in carbonate alkaline stress responses. Hence, in this study, we identified the P-type II Ca(2+)ATPase family genes in soybean genome, determined their chromosomal location and gene architecture, and analyzed their amino acid sequence and evolutionary relationship. Based on above results, we pointed out the existence of gene duplication for soybean Ca(2+)ATPases. Then, we investigated the expression profiles of the ACA subfamily genes in wild soybean (Glycine soja) under carbonate alkaline stress, and functionally characterized one representative gene GsACA1 by using transgenic alfalfa. Our results suggested that GsACA1 overexpression in alfalfa obviously increased plant tolerance to both carbonate alkaline and neutral salt stresses, as evidenced by lower levels of membrane permeability and MDA content, but higher levels of SOD activity, proline concentration and chlorophyll content under stress conditions. Taken together, for the first time, we reported a P-type II Ca(2+)ATPase from wild soybean, GsACA1, which could positively regulate plant tolerance to both carbonate alkaline and neutral salt stresses. PMID:26801329

  16. Genetic variation of the weaning weight of beef cattle as a function of accumulated heat stress.

    PubMed

    Santana, M L; Bignardi, A B; Eler, J P; Ferraz, J B S

    2016-04-01

    The objective of this study was to identify the genetic variation in the weaning weight (WW) of beef cattle as a function of heat stress. The WWs were recorded at approximately 205 days of age in three Brazilian beef cattle populations: Nelore (93,616), Brangus (18,906) and Tropical Composite (62,679). In view of the cumulative nature of WW, the effect of heat stress was considered as the accumulation of temperature and humidity index units (ACTHI) from the animal's birth to weaning. A reaction norm model was used to estimate the (co)variance components of WW across the ACTHI scale. The accumulation of THI units from birth to weaning negatively affected the WW. The definition of accumulated THI units as an environmental descriptor permitted to identify important genetic variation in the WW as a function of heat stress. As evidence of genotype by environment interaction, substantial heterogeneity was observed in the (co)variance components for WW across the environmental gradient. In this respect, the best animals in less stressful environments are not necessarily the best animals in more stressful environments. Furthermore, the response to selection for WW is expected to be lower in more stressful environments. PMID:26061790

  17. Ultra-endurance exercise induces stress and inflammation and affects circulating hematopoietic progenitor cell function.

    PubMed

    Stelzer, I; Kröpfl, J M; Fuchs, R; Pekovits, K; Mangge, H; Raggam, R B; Gruber, H-J; Prüller, F; Hofmann, P; Truschnig-Wilders, M; Obermayer-Pietsch, B; Haushofer, A C; Kessler, H H; Mächler, P

    2015-10-01

    Although amateur sports have become increasingly competitive within recent decades, there are as yet few studies on the possible health risks for athletes. This study aims to determine the impact of ultra-endurance exercise-induced stress on the number and function of circulating hematopoietic progenitor cells (CPCs) and hematological, inflammatory, clinical, metabolic, and stress parameters in moderately trained amateur athletes. Following ultra-endurance exercise, there were significant increases in leukocytes, platelets, interleukin-6, fibrinogen, tissue enzymes, blood lactate, serum cortisol, and matrix metalloproteinase-9. Ultra-endurance exercise did not influence the number of CPCs but resulted in a highly significant decline of CPC functionality after the competition. Furthermore, Epstein-Barr virus was seen to be reactivated in one of seven athletes. The link between exercise-induced stress and decline of CPC functionality is supported by a negative correlation between cortisol and CPC function. We conclude that ultra-endurance exercise induces metabolic stress and an inflammatory response that affects not only mature hematopoietic cells but also the function of the immature hematopoietic stem and progenitor cell fraction, which make up the immune system and provide for regeneration. PMID:25438993

  18. The Effect of Perceived Stress and Family Functioning on People with Type 2 Diabetes Mellitus

    PubMed Central

    Bhandary, Bhagyashree; Rao, Satheesh; T.S., Sanal

    2013-01-01

    Background: Various studies have suggested that support from a patient’s family can facilitate his/her recovery from a physical illness and improve the ability of the patient to deal with consequences of Type 2 Diabetes. Stress is considered to play a major role in influencing Type 2 Diabetes Mellitus. Aim: To determine the roles of Perceived Stress and Family functioning on behaviours of individuals with Type 2 Diabetes Mellitus. Material and Methods: The present study included 250 Diabetics as per the WHO criteria and 250 Non-Diabetics. Questionnaires were given to them to obtain data. Results: Stress was found to be high among Diabetics (22.17%) as compared to that in non-Diabetics (16.92%). Family assessment showed a significant difference among its subscales when it was compared between Diabetics and Non-Diabetics. Conclusion: Perceived stress influences Type 2 Diabetes Mellitus. Role played by the Family is significant in managing Diabetes. PMID:24551677

  19. Decreased SGK1 Expression and Function Contributes to Behavioral Deficits Induced by Traumatic Stress

    PubMed Central

    Licznerski, Pawel; Duric, Vanja; Banasr, Mounira; Alavian, Kambiz N.; Ota, Kristie T.; Kang, Hyo Jung; Jonas, Elizabeth A.; Ursano, Robert; Krystal, John H.; Duman, Ronald S.

    2015-01-01

    Exposure to extreme stress can trigger the development of major depressive disorder (MDD) as well as post-traumatic stress disorder (PTSD). The molecular mechanisms underlying the structural and functional alterations within corticolimbic brain regions, including the prefrontal cortex (PFC) and amygdala of individuals subjected to traumatic stress, remain unknown. In this study, we show that serum and glucocorticoid regulated kinase 1 (SGK1) expression is down-regulated in the postmortem PFC of PTSD subjects. Furthermore, we demonstrate that inhibition of SGK1 in the rat medial PFC results in helplessness- and anhedonic-like behaviors in rodent models. These behavioral changes are accompanied by abnormal dendritic spine morphology and synaptic dysfunction. Together, the results are consistent with the possibility that altered SGK1 signaling contributes to the behavioral and morphological phenotypes associated with traumatic stress pathophysiology. PMID:26506154

  20. Decreased SGK1 Expression and Function Contributes to Behavioral Deficits Induced by Traumatic Stress.

    PubMed

    Licznerski, Pawel; Duric, Vanja; Banasr, Mounira; Alavian, Kambiz N; Ota, Kristie T; Kang, Hyo Jung; Jonas, Elizabeth A; Ursano, Robert; Krystal, John H; Duman, Ronald S

    2015-10-01

    Exposure to extreme stress can trigger the development of major depressive disorder (MDD) as well as post-traumatic stress disorder (PTSD). The molecular mechanisms underlying the structural and functional alterations within corticolimbic brain regions, including the prefrontal cortex (PFC) and amygdala of individuals subjected to traumatic stress, remain unknown. In this study, we show that serum and glucocorticoid regulated kinase 1 (SGK1) expression is down-regulated in the postmortem PFC of PTSD subjects. Furthermore, we demonstrate that inhibition of SGK1 in the rat medial PFC results in helplessness- and anhedonic-like behaviors in rodent models. These behavioral changes are accompanied by abnormal dendritic spine morphology and synaptic dysfunction. Together, the results are consistent with the possibility that altered SGK1 signaling contributes to the behavioral and morphological phenotypes associated with traumatic stress pathophysiology. PMID:26506154

  1. Stress and Resilience in Functional Somatic Syndromes – A Structural Equation Modeling Approach

    PubMed Central

    Fischer, Susanne; Lemmer, Gunnar; Gollwitzer, Mario; Nater, Urs M.

    2014-01-01

    Background Stress has been suggested to play a role in the development and perpetuation of functional somatic syndromes. The mechanisms of how this might occur are not clear. Purpose We propose a multi-dimensional stress model which posits that childhood trauma increases adult stress reactivity (i.e., an individual's tendency to respond strongly to stressors) and reduces resilience (e.g., the belief in one's competence). This in turn facilitates the manifestation of functional somatic syndromes via chronic stress. We tested this model cross-sectionally and prospectively. Methods Young adults participated in a web survey at two time points. Structural equation modeling was used to test our model. The final sample consisted of 3′054 participants, and 429 of these participated in the follow-up survey. Results Our proposed model fit the data in the cross-sectional (χ2(21)  = 48.808, p<.001, CFI  = .995, TLI  = .992, RMSEA  = .021, 90% CI [.013.029]) and prospective analyses (χ2(21)  = 32.675, p<.05, CFI  = .982, TLI  = .969, RMSEA  = .036, 90% CI [.001.059]). Discussion Our findings have several clinical implications, suggesting a role for stress management training in the prevention and treatment of functional somatic syndromes. PMID:25396736

  2. Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence.

    PubMed

    Lagasse, Linda L; Conradt, Elisabeth; Karalunas, Sarah L; Dansereau, Lynne M; Butner, Jonathan E; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles R; Whitaker, Toni M; Lester, Barry M

    2016-08-01

    Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (a) how these transactions originate, (b) whether they persist over time to contribute to the development of problem behavior and (c) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth to age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior. PMID:27427803

  3. Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence

    PubMed Central

    LaGasse, Linda L.; Conradt, Elisabeth; Karalunas, Sarah L.; Dansereau, Lynne M.; Butner, Jonathan E.; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles R.; Whitaker, Toni M.; Lester, Barry M.

    2016-01-01

    Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (1) how these transactions originate, (2) whether they persist over time to contribute to the development of problem behavior and (3) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth-age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior. PMID:27427803

  4. Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

    PubMed Central

    Shu, Longfei; Laurila, Anssi; Räsänen, Katja

    2015-01-01

    Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

  5. Life stress in adolescence predicts early adult reward-related brain function and alcohol dependence

    PubMed Central

    Shaw, Daniel S.; Sitnick, Stephanie L.; Musselman, Samuel C.; Forbes, Erika E.

    2015-01-01

    Stressful life events increase vulnerability to problematic alcohol use, and they may do this by disrupting reward-related neural circuitry. This is particularly relevant for adolescents because alcohol use rises sharply after mid-adolescence and alcohol abuse peaks at age 20. Adolescents also report more stressors compared with children, and neural reward circuitry may be especially vulnerable to stressors during adolescence because of prefrontal cortex remodeling. Using a large sample of male participants in a longitudinal functional magnetic resonance imaging study (N = 157), we evaluated whether cumulative stressful life events between the ages of 15 and 18 were associated with reward-related brain function and problematic alcohol use at age 20 years. Higher cumulative stressful life events during adolescence were associated with decreased response in the medial prefrontal cortex (mPFC) during monetary reward anticipation and following the receipt of monetary rewards. Stress-related decreases in mPFC response during reward anticipation and following rewarding outcomes were associated with the severity of alcohol dependence. Furthermore, mPFC response mediated the association between stressful life events and later symptoms of alcohol dependence. These data are consistent with neurobiological models of addiction that propose that stressors during adolescence increase risk for problematic alcohol use by disrupting reward circuit function. PMID:24795442

  6. Determination and modeling of residual stress in functionally graded WC-Co

    NASA Astrophysics Data System (ADS)

    Tahvilian, Leila

    Gradual variations in composition and/or structure through the volume of functionally graded materials (FGMs) generally result in corresponding continuous spatial variations in mechanical/physical properties, and often in significant residual stresses that develop during processing. Due to inhomogeneous properties in these materials, residual stress measurement in FGMs can be a very challenging problem. In this study, residual stresses in functionally graded cemented tungsten carbide (FG-WC-Co) were investigated by numerical, analytical and experimental approaches by means of a layer removal technique. The numerical method consisted of finite element analysis (FEA) modeling for the FGM plate, in order to calculate residual stress distribution over the volume and to develop a method for predicting residual stress levels in closely related materials. The analytical procedure embodied a mathematical approach to determine residual stress distributions, and analytically determined values are compared with those obtained from FEA modeling and experimental results. The experimental approach consisted of fabricating and heat treating FG-WC-Co flat samples, then measuring strain changes by strain gauge after each sequential layer removal from the opposite side of the specimen from the graded region. Good agreement was found between analytical, numerical and experimental results. Furthermore, thermal residual stress distribution in FG-WC-Co hollow cylinder was examined with an emphasis on the effects of key variables, the gradient profile and the gradient thickness, on the magnitude and distribution of the stress field. An analytical direct solution based on solving the governing equations of a cylinder composed of a uniform inner core and a functionally graded outer shell was developed. The cylindrical compound was considered as two separate elements: homogeneous cylinder and functionally graded shell. Material properties, such as the elastic modulus and the coefficient of

  7. Structural and functional alterations to rat medial prefrontal cortex following chronic restraint stress and recovery

    PubMed Central

    Goldwater, Deena S.; Pavlides, Constantine; Hunter, Richard G.; Bloss, Erik B.; Hof, Patrick R.; McEwen, Bruce S.; Morrison, John H.

    2009-01-01

    Chronic stress has been shown in animal models to result in altered dendritic morphology of pyramidal neurons of the medial prefrontal cortex (mPFC). It has been hypothesized that the stress-induced dendritic retractions and spine loss lead to disrupted connectivity that results in stress-induced functional impairment of mPFC. While these alterations were initially viewed as a neurodegenerative event, it has recently been established that stress induced dendritic alterations are reversible if animals are given time to recover from chronic stress. However, whether spine growth accompanies dendritic extension remains to be demonstrated. It is also not known if recovery-phase dendritic extension allows for re-establishment of functional capacity. The goal of this study, therefore, was to characterize the structural and functional effects of chronic stress and recovery on the infralimbic (IL) region of the rat mPFC. We compared neuronal morphology of layer V IL pyramidal neurons from animals subjected to 21 days of chronic restraint stress (CRS) to those that experienced CRS followed by a 21 day recovery period. Layer V pyramidal cell functional capacity was assessed by intra-IL long-term potentiation (LTP) both in the absence and presence of SKF38393, a dopamine receptor partial agonist and a known PFC LTP modulator. We found that stress-induced IL apical dendritic retraction and spine loss co-occur with receptor-mediated impairments to catecholaminergic facilitation of synaptic plasticity. We also found that while post-stress recovery did not reverse distal dendritic retraction, it did result in over-extension of proximal dendritic neuroarchitecture and spine growth as well as a full reversal of CRS-induced impairments to catecholaminergic-mediated synaptic plasticity. Our results support the hypothesis that disease-related PFC dysfunction is a consequence of network disruption secondary to altered structural and functional plasticity and that circuitry

  8. Stress and its relation to endocrine function in captive female Siberian sturgeon (Acipenser baeri).

    PubMed

    Hamlin, Heather J; Edwards, Thea M; Moore, Brandon C; Main, Kevan L; Guillette, Louis J

    2007-01-01

    Stress responses to numerous environmental conditions have been studied in a wide range of fish species. Defining the relationship between stress and endocrine function is particularly critical to long-lived species such as sturgeons, whose economic viability relies heavily on proper endocrine function for the production of caviar. In this study, we examined the induced stress response, defined by plasma cortisol and glucose concentrations, and its relationship to plasma 17beta-estradiol, testosterone and 11-ketotestosterone concentrations in cultured female Siberian sturgeon (Acipenser baeri). Fish were acutely stressed using capture and confinement for a period of 4 h, and blood samples were drawn according to four treatment regimens: treatment 1, fish were bled at 0 h; treatment 2, fish were serially bled at 0 h, 1 h and 4 h; treatment 3, fish were bled at 1 h and 4 h; treatment 4, fish were bled at 4 h only. Fish were surgically sexed immediately after drawing blood at 0 h. After 1 h of acute stress, fish demonstrated a marked increase in plasma cortisol concentration, which remained elevated throughout the 4-h sampling period. The plasma concentration of sex steroids did not exhibit an inverse relationship with plasma cortisol concentration. Plasma testosterone concentration was significantly elevated during the periods of greatest stress. Plasma estradiol and 11-ketotestosterone (11-KT) concentrations were not affected by the acute stressors in this experiment. Serial bleedings, however, affected the associated stress response, which is an important consideration for future studies with this species. This is the first study to define the relationship between stress and possible changes in sex steroid concentration in this threatened and commercially important species. PMID:17622217

  9. Stress-induced breakdown of intestinal barrier function in the rat: reversal by wood creosote.

    PubMed

    Kuge, Tomoo; Greenwood-Van Meerveld, Beverley; Sokabe, Masahiro

    2006-07-24

    Our previous studies demonstrated that wood creosote (Seirogan) inhibits intestinal secretion and normalizes the transport of electrolytes and water in rats subjected to restraint stress. The goal of the present study was to examine whether wood creosote has a protective effect against stress-induced breakdown of intestinal barrier function. F-344 rats were subjected to 90-min water avoidance stress (WAS) with wood creosote (30 mg/kg) or vehicle administered intragastrically 30 min prior to WAS. Sham stressed rats received wood creosote or vehicle treatment but did not experience the WAS. All rats were euthanized at the end of the WAS or sham-stress and the jejunum and colon were isolated. Epithelial transport was studied in modified Ussing chambers. Spontaneous secretion was assessed by electrophysiological measurement of the short circuit current (I(sc)) while electrical conductance (G) was calculated from the potential difference (PD) and I(sc) using Ohm's law. Intestinal permeability was defined by the mucosal-to-serosal flux of horseradish peroxidase (HRP). WAS significantly elevated basal I(sc) and G and increased epithelial permeability to HRP in the jejunum but not in the colon. Wood creosote resulted in a significant reduction of the stress-induced increase in I(sc), G and the mucosal-to-serosal flux of HRP compared to the vehicle-treated group. Wood creosote caused no significant effects in sham-stressed rats. The results suggest that oral administration of wood creosote may prevent stress-induced diarrhea by preventing aversive effects on small intestinal secretion and barrier function. PMID:16643959

  10. The reduction of occupational stress among elderly lawyers: the creation of a functional niche.

    PubMed

    Meltzer, M W

    1981-01-01

    The question of how older lawyers function in the context of what is generally a high stress occupation is examined from data drawn from a random stratified sample of 130 members of the legal profession. It is shown that elderly lawyers are able to reduce work stress (largely deriving from volume, responsibility, clients, and trials) by control over the quantity and focus of their work, as well as through client selection. Elderly lawyers are able to create a relatively stress free work role, which is in fact a functional niche for them within the profession. The result is high job satisfaction and low rates of retirement among elderly practitioners. Two factors: work role compensation and work role autonomy, are isolated from the legal data and proposed as important variables in a general theory of retirement behavior. PMID:7343503

  11. Replication stress caused by low MCM expression limits fetal erythropoiesis and hematopoietic stem cell functionality

    PubMed Central

    Alvarez, Silvia; Díaz, Marcos; Flach, Johanna; Rodriguez-Acebes, Sara; López-Contreras, Andrés J.; Martínez, Dolores; Cañamero, Marta; Fernández-Capetillo, Oscar; Isern, Joan; Passegué, Emmanuelle; Méndez, Juan

    2015-01-01

    Replicative stress during embryonic development influences ageing and predisposition to disease in adults. A protective mechanism against replicative stress is provided by the licensing of thousands of origins in G1 that are not necessarily activated in the subsequent S-phase. These ‘dormant' origins provide a backup in the presence of stalled forks and may confer flexibility to the replication program in specific cell types during differentiation, a role that has remained unexplored. Here we show, using a mouse strain with hypomorphic expression of the origin licensing factor mini-chromosome maintenance (MCM)3 that limiting origin licensing in vivo affects the functionality of hematopoietic stem cells and the differentiation of rapidly-dividing erythrocyte precursors. Mcm3-deficient erythroblasts display aberrant DNA replication patterns and fail to complete maturation, causing lethal anemia. Our results indicate that hematopoietic progenitors are particularly sensitive to replication stress, and full origin licensing ensures their correct differentiation and functionality. PMID:26456157

  12. Stem cell function and stress response are controlled by protein synthesis.

    PubMed

    Blanco, Sandra; Bandiera, Roberto; Popis, Martyna; Hussain, Shobbir; Lombard, Patrick; Aleksic, Jelena; Sajini, Abdulrahim; Tanna, Hinal; Cortés-Garrido, Rosana; Gkatza, Nikoletta; Dietmann, Sabine; Frye, Michaela

    2016-06-16

    Whether protein synthesis and cellular stress response pathways interact to control stem cell function is currently unknown. Here we show that mouse skin stem cells synthesize less protein than their immediate progenitors in vivo, even when forced to proliferate. Our analyses reveal that activation of stress response pathways drives both a global reduction of protein synthesis and altered translational programmes that together promote stem cell functions and tumorigenesis. Mechanistically, we show that inhibition of post-transcriptional cytosine-5 methylation locks tumour-initiating cells in this distinct translational inhibition programme. Paradoxically, this inhibition renders stem cells hypersensitive to cytotoxic stress, as tumour regeneration after treatment with 5-fluorouracil is blocked. Thus, stem cells must revoke translation inhibition pathways to regenerate a tissue or tumour. PMID:27306184

  13. Stress, ageing and their influence on functional, cellular and molecular aspects of the immune system.

    PubMed

    Vitlic, Ana; Lord, Janet M; Phillips, Anna C

    2014-06-01

    The immune response is essential for keeping an organism healthy and for defending it from different types of pathogens. It is a complex system that consists of a large number of components performing different functions. The adequate and controlled interaction between these components is necessary for a robust and strong immune response. There are, however, many factors that interfere with the way the immune response functions. Stress and ageing now consistently appear in the literature as factors that act upon the immune system in the way that is often damaging. This review focuses on the role of stress and ageing in altering the robustness of the immune response first separately, and then simultaneously, discussing the effects that emerge from their interplay. The special focus is on the psychological stress and the impact that it has at different levels, from the whole system to the individual molecules, resulting in consequences for physical health. PMID:24562499

  14. Stress and adrenergic function: HIF1α, a potential regulatory switch.

    PubMed

    Wong, Dona Lee; Tai, T C; Wong-Faull, David C; Claycomb, Robert; Siddall, Brenda J; Bell, Rose Ann; Kvetnansky, Richard

    2010-11-01

    Stress elicits adrenal epinephrine and cortisol release into the bloodstream to initiate physiological and behavioral responses to counter and overcome stress, the classic "fight or flight" response (Cannon and De La Paz, Am J Physiol 28:64-70, 1911). Stress and the stress hormone epinephrine also contribute to the pathophysiology of illness, e.g., behavioral disorders, cardiovascular disease, and immune dysfunction. Epinephrine itself is regulated by stress through its biosynthesis by phenylethanolamine N-methyltransferase (PNMT, EC 2.1.1.28). Single and repeated immobilization (IMMO) stress in rats stimulates adrenal PNMT mRNA and protein expression via the transcription factors, Egr-1 and Sp1. Moderate hypoxic stress increases PNMT promoter-driven gene expression and endogenous PNMT mRNA and protein in PC12 cells. Induction is initiated through cAMP and PLC signaling, with PKA, PKC, PI3K, ERK1/2 MAPK, and p38 MAPK continuing downstream signal transduction, followed by activation of HIF1α, Egr-1, and Sp1. While functional Egr-1 and Sp1 binding sites exist within the proximal PNMT promoter, a putative hypoxia response element is a weak HIF binding site. Yet, HIF1α overexpression increases PNMT promoter-driven luciferase activity and endogenous PNMT. When the Egr-1 or Sp1 sites are mutated, HIF1α does not stimulate the PNMT promoter. siRNA knock down of Egr-1 or Sp1 prevents promoter activation while siRNA knock down of HIF1α inhibits Egr-1 and Sp1 induction. Findings suggest that hypoxia activates the PNMT gene indirectly via HIF1α stimulation of Egr-1 and Sp1. Thus, for stress-induced illnesses where adrenergic dysfunction is implicated, HIF1α may be an "on-off" switch regulating adrenergic responses to stress and a potential target for therapeutic intervention. PMID:21046459

  15. Systematic Analysis of Integrated Gene Functional Network of Four Chronic Stress-related Lifestyle Disorders

    PubMed Central

    Roy, Souvick; Chakraborty, Abhik; Ghosh, Chinmoy; Banerjee, Birendranath

    2015-01-01

    Background: Stress is a term used to define factors involved in changes in the physiological balances resulting in disease conditions. Chronic exposure to stress conditions in modern lifestyles has resulted in a group of disorders called lifestyle disorders. Genetic background and environmental factors are interrelated to lifestyle in determining the health status of individuals. Hence, identification of disease-associated genes is the primary step toward explanations of pathogenesis of these diseases. In functional genomics, large-scale molecular and physiological data are used for the identification of causative genes associated with a disease. Aim: The objective of our study was to find a common set of genes involved in chronic stress-related lifestyle diseases such as cardiovascular diseases (CVDs), type 2 diabetes (T2D), hypertension (HTN), and obesity. Materials and Methods: In our study, we have performed a systematic analysis of the functional gene network of four chronic stress-related lifestyle diseases by retrieving genes from published databases. We have tried to systematically construct a functional protein-protein interaction (PPI) network. The goals of establishing this network were the functional enrichment study of interacting partners as well as functional disease ontology annotation (FunDO) of the enriched genes. Results: This study enabled the identification of key genes involved in these stress-related lifestyle diseases by prioritizing candidate genes based on their degree of involvement. In this systematic analysis, we have found key genes for these diseases based on their involvement and association at the gene network level and PPI. Conclusion: We have deciphered a group of genes that in combination play a crucial role and may impact the function of the whole genome in the four lifestyle disorders mentioned. PMID:27330735

  16. Nanoscale patterning of extracellular matrix alters endothelial function under shear stress

    PubMed Central

    Nakayama, Karina H.; Surya, Vinay N.; Gole, Monica; Walker, Travis; Yang, Weiguang; Lai, Edwina S.; Ostrowski, Maggie; Fuller, Gerald G.; Dunn, Alexander R.; Huang, Ngan F.

    2016-01-01

    The role of nanotopographical extracellular matrix (ECM) cues on vascular endothelial cell (EC) organization and function is not well-understood, despite the composition of nano- to micro-scale fibrillar ECMs within blood vessels. Instead, the predominant modulator of EC organization and function is traditionally thought to be hemodynamic shear stress, in which uniform shear stress induces parallel-alignment of ECs with anti-inflammatory function, whereas disturbed flow induce pro-inflammatory cells in disorganized configuration. Since shear stress acts on ECs by applying a mechanical force concomitant with inducing spatial patterning of the cells, we sought to decouple the effects of shear stress using parallel-aligned nanofibrillar collagen films that induce parallel EC alignment prior to stimulation with disturbed flow resulting from spatial wall shear stress gradients. Using real time live-cell imaging, we tracked the alignment, migration trajectories, proliferation, and anti-inflammatory behavior of ECs when they were cultured on parallel-aligned or randomly oriented nanofibrillar films. Intriguingly, ECs cultured on aligned nanofibrillar films remained well-aligned and migrated predominantly along the direction of aligned nanofibrils, despite exposure to shear stress orthogonal to the direction of the aligned nanofibrils. Furthermore, in stark contrast to ECs cultured on randomly oriented films, ECs on aligned nanofibrillar films exposed to disturbed flow had significantly reduced inflammation and proliferation, while maintaining intact intercellular junctions. This work reveals fundamental insights into the importance of nanoscale ECM interactions in the maintenance of endothelial function. Importantly, it provides new insight into how ECs respond to opposing cues derived from nanotopography and mechanical shear force, and has strong implications in the design of polymeric conduits and bioengineered tissues. PMID:26670737

  17. Early Childcare, Executive Functioning, and the Moderating Role of Early Stress Physiology

    ERIC Educational Resources Information Center

    Berry, Daniel; Willoughby, Michael T.; Blair, Clancy; Ursache, Alexandra; Granger, Douglas A.

    2014-01-01

    Intervention studies indicate that children's childcare experiences can be leveraged to support the development of executive functioning (EF). The role of more normative childcare experiences is less clear. Increasingly, theory and empirical work suggest that individual differences in children's physiological stress systems may be…

  18. Family Ranching and Farming: A Consensus Management Model to Improve Family Functioning and Decrease Work Stress.

    ERIC Educational Resources Information Center

    Zimmerman, Toni Schindler; Fetsch, Robert J.

    1994-01-01

    Notes that internal and external threats could squeeze ranch and farm families out of business. Offers six-step Consensus Management Model that combines strategic planning with psychoeducation/family therapy. Describes pilot test with intergenerational ranch family that indicated improvements in family functioning, including reduced stress and…

  19. Emotional-volitional components of operator reliability. [sensorimotor function testing under stress

    NASA Technical Reports Server (NTRS)

    Mileryan, Y. A.

    1975-01-01

    Sensorimotor function testing in a tracking task under stressfull working conditions established a psychological characterization for a successful aviation pilot: Motivation significantly increased the reliability and effectiveness of their work. Their acitivities were aimed at suppressing weariness and the feeling of fear caused by the stress factors; they showed patience, endurance, persistence, and a capacity for lengthy volitional efforts.

  20. Acute brief heat stress in late gestation alters neonatal calf innate immune functions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress (HS), as one of the environmental stressors affecting the dairy industry, compromises the cow's milk production, immune function, and reproductive system. However, few studies have looked at how prenatal HS affects the offspring. The objective of this study was to evaluate the effect of ...

  1. Child Behavior Problems, Teacher Executive Functions, and Teacher Stress in Head Start Classrooms

    ERIC Educational Resources Information Center

    Friedman-Krauss, Allison H.; Raver, C. Cybele; Neuspiel, Juliana M.; Kinsel, John

    2014-01-01

    Research Findings: The current article explores the relationship between teachers' perceptions of child behavior problems and preschool teacher job stress, as well as the possibility that teachers' executive functions moderate this relationship. Data came from 69 preschool teachers in 31 early childhood classrooms in 4 Head Start centers…

  2. MACROSCOPIC APPROACHES TO ROOT WATER UPTAKE AS A FUNCTION OF WATER AND SALINITY STRESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Computer simulation models can be important tools for analyzing and managing site-specific irrigation, soil salinization, or crop production problems. For many of these problems, computer analyses require simulations of root water uptake as a function of water and salinity stress. We give an over...

  3. Grandmother Support, Family Functioning, and Parenting Stress in Families with a Child with a Disability

    ERIC Educational Resources Information Center

    Tumbarello, Natasha

    2010-01-01

    This study examined the relationship among grandparent support, family functioning, and parental stress on families with children with and without disabilities between the ages of 2 and 12 years. Families are viewed as an ever-changing complex system with reciprocal interactions. One possible stressor on the family system is the birth of a child…

  4. Stress and Family Functioning in Parents of Girls with Rett Syndrome.

    ERIC Educational Resources Information Center

    Perry, Adrienne; And Others

    1992-01-01

    This survey of parents of 29 girls with Rett syndrome found that subjects reported more stress, lower marital satisfaction, and certain adaptations in family functioning compared to norms. However, most parents scored in the normal range. Scores were not related to socioeconomic status or characteristics of the affected child. (DB)

  5. Latent Classes of Adolescent Posttraumatic Stress Disorder Predict Functioning and Disorder after 1 Year

    ERIC Educational Resources Information Center

    Ayer, Lynsay; Danielson, Carla Kmett; Amstadter, Ananda B.; Ruggiero, Ken; Saunders, Ben; Kilpatrick, Dean

    2011-01-01

    Objective: To identify latent classes of posttraumatic stress disorder (PTSD) symptoms in a national sample of adolescents, and to test their associations with PTSD and functional impairment 1 year later. Method: A total of 1,119 trauma-exposed youth aged 12 through 17 years (mean = 14.99 years, 51% female and 49% male) participating in the…

  6. Asymmetric Yield Function Based on the Stress Invariants for Pressure Sensitive Metals

    SciTech Connect

    Jeong Wahn Yoon; Yanshan Lou; Jong Hun Yoon; Michael V. Glazoff

    2014-05-01

    A general asymmetric yield function is proposed with dependence on the stress invariants for pressure sensitive metals. The pressure sensitivity of the proposed yield function is consistent with the experimental result of Spitzig and Richmond (1984) for steel and aluminum alloys while the asymmetry of the third invariant is preserved to model strength differential (SD) effect of pressure insensitive materials. The proposed yield function is transformed in the space of the stress triaxaility, the von Mises stress and the normalized invariant to theoretically investigate the possible reason of the SD effect. The proposed plasticity model is further extended to characterize the anisotropic behavior of metals both in tension and compression. The extension of the yield function is realized by introducing two distinct fourth-order linear transformation tensors of the stress tensor for the second and third invariants, respectively. The extended yield function reasonably models the evolution of yield surfaces for a zirconium clock-rolled plate during in-plane and through-thickness compression reported by Plunkett et al. (2007). The extended yield function is also applied to describe the orthotropic behavior of a face-centered cubic metal of AA 2008-T4 and two hexagonal close-packed metals of high-purity-titanium and AZ31 magnesium alloy. The orthotropic behavior predicted by the generalized model is compared with experimental results of these metals. The comparison validates that the proposed yield function provides sufficient predictability on SD effect and anisotropic behavior both in tension and compression. When it is necessary to consider r-value anisotropy, the proposed function is efficient to be used with nonassociated flow plasticity by introducing a separate plastic potential for the consideration of r-values as shown in Stoughton & Yoon (2004, 2009).

  7. Evaluating Effects of Heat Stress on Cognitive Function among Workers in a Hot Industry

    PubMed Central

    Mazloumi, Adel; Golbabaei, Farideh; Mahmood Khani, Somayeh; Kazemi, Zeinab; Hosseini, Mostafa; Abbasinia, Marzieh; Farhang Dehghan, Somayeh

    2014-01-01

    Background:Heat stress, as one of the most common occupational health problems, can impair operators' cognitive processes. The aim of this study was to evaluate the impact of thermal stress on cognitive function among workers in a hot industry. Methods: In this cross-sectional study conducted in Malibel Saipa Company in 2013, workers were assigned into two groups: one group were exposed to heat stress (n=35), working in casting unit and the other group working in machining unit (n=35) with a normal air conditioning. Wet Bulb Globe Temperature was measured at three heights of ankle, abdomen, and head. In order to evaluate the effects of heat stress on attention and reaction time, Stroop tests 1, 2, and 3 were conducted before starting the work and during the work. Results: A significant positive correlation was observed between WBGT and test duration (P=0.01) and reaction time of Stroop test 3 (P=0.047), and between number of errors in Stroop tests 1, 2, and 3, during the work (P= 0.001). Moreover, Stroop test 3 showed a significant higher score for both test duration and reaction time of workers in case group. Conclusion: Results of the present study, conducted in a real work environment, confirmed the impairment of cognitive functions, including selective attention and reaction time, under heat stress conditions. PMID:25649311

  8. Circadian clock functioning is linked to acute stress reactivity in rats.

    PubMed

    Weibel, L; Maccari, S; Van Reeth, O

    2002-10-01

    At least two major physiological systems are involved in the adaptation of the organism to environmental challenges: the circadian system and the stress reaction. This study addressed the possibility that interindividual differences in stress sensitivity and in the functioning of the circadian system are related. At 2 months of age, corticosterone secretion in response to a 20-min restraint stress was assessed in 9 Sprague-Dawley rats for which running wheel activity was recorded as a rhythmic behavioral marker of the circadian clock. Two weeks later, the adaptive response of the circadian system to an abrupt shift in the light:dark (LD) cycle was assessed in those rats using a jet-lag paradigm. Finally, after resynchronization to the new LD cycle, rats were transferred to constant darkness to assess the free-running period of their circadian rhythm of running-wheel activity. Results indicate that stress-induced corticosterone secretion was (1) positively correlated with the number of days to resynchronize the circadian activity rhythm to the new LD cycle, and with the value of its free-running period, and (2) negatively correlated with the intensity of daily locomotor activity. Those data, emphasizing the interactions between the stress response of an organism and the functioning of its circadian system, could explain interindividual differences in humans' susceptibility to shift work or other circadian-related disorders. PMID:12375620

  9. The location of Airy-0, the Mars prime meridian reference, from stereo photogrammetric processing of THEMIS IR imaging and digital elevation data

    NASA Astrophysics Data System (ADS)

    Duxbury, T. C.; Christensen, P.; Smith, D. E.; Neumann, G. A.; Kirk, R. L.; Caplinger, M. A.; Albee, A. A.; Seregina, N. V.; Neukum, G.; Archinal, B. A.

    2014-12-01

    The small crater Airy-0 was selected from Mariner 9 images to be the reference for the Mars prime meridian. Initial analyses in the year 2000 tied Viking Orbiter and Mars Orbiter Camera images of Airy-0 to the evolving Mars Orbiter Laser Altimeter global digital terrain model to update the location of Airy-0. Based upon this tie and radiometric tracking of landers/rovers from Earth, new expressions for the Mars spin axis direction, spin rate, and prime meridian epoch value were produced to define the orientation of the Martian surface in inertial space over time. Since the Mars Global Surveyor mission and Mars Orbiter Laser Altimeter global digital terrain model were completed some time ago, a more exhaustive study has been performed to determine the accuracy of the Airy-0 location and orientation of Mars at the standard epoch. Thermal Emission Imaging System (THEMIS) IR image cubes of the Airy and Gale crater regions were tied to the global terrain grid using precision stereo photogrammetric image processing techniques. The Airy-0 location was determined to be about 0.001° east of its predicted location using the currently defined International Astronomical Union (IAU) prime meridian location. Information on this new location and how it was derived will be provided to the NASA Mars Exploration Program Geodesy and Cartography Working Group for their assessment. This NASA group will make a recommendation to the IAU Working Group on Cartographic Coordinates and Rotational Elements to update the expression for the Mars spin axis direction, spin rate, and prime meridian location.

  10. Tumor suppressor BTG1 promotes PRMT1-mediated ATF4 function in response to cellular stress

    PubMed Central

    Tijchon, Esther; van Ingen Schenau, Dorette; van Emst, Liesbeth; Levers, Marloes; Palit, Sander A.L.; Rodenbach, Caroline; Poelmans, Geert; Hoogerbrugge, Peter M.; Shan, Jixiu; Kilberg, Michael S.; Scheijen, Blanca; van Leeuwen, Frank N.

    2016-01-01

    Cancer cells are frequently exposed to physiological stress conditions such as hypoxia and nutrient limitation. Escape from stress-induced apoptosis is one of the mechanisms used by malignant cells to survive unfavorable conditions. B-cell Translocation Gene 1 (BTG1) is a tumor suppressor that is frequently deleted in acute lymphoblastic leukemia and recurrently mutated in diffuse large B cell lymphoma. Moreover, low BTG1 expression levels have been linked to poor outcome in several solid tumors. How loss of BTG1 function contributes to tumor progression is not well understood. Here, using Btg1 knockout mice, we demonstrate that loss of Btg1 provides a survival advantage to primary mouse embryonic fibroblasts (MEFs) under stress conditions. This pro-survival effect involves regulation of Activating Transcription Factor 4 (ATF4), a key mediator of cellular stress responses. We show that BTG1 interacts with ATF4 and positively modulates its activity by recruiting the protein arginine methyl transferase PRMT1 to methylate ATF4 on arginine residue 239. We further extend these findings to B-cell progenitors, by showing that loss of Btg1 expression enhances stress adaptation of mouse bone marrow-derived B cell progenitors. In conclusion, we have identified the BTG1/PRMT1 complex as a new modifier of ATF4 mediated stress responses. PMID:26657730

  11. Function of ABA in Stomatal Defense against Biotic and Drought Stresses

    PubMed Central

    Lim, Chae Woo; Baek, Woonhee; Jung, Jangho; Kim, Jung-Hyun; Lee, Sung Chul

    2015-01-01

    The plant hormone abscisic acid (ABA) regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses—especially ABA receptors—have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR)/PYR-like (PYL) or regulatory component of ABA receptor (RCAR) family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases. PMID:26154766

  12. Finite element analysis of the residual thermal stresses on functionally gradated dental restorations.

    PubMed

    Henriques, B; Miranda, G; Gasik, M; Souza, J C M; Nascimento, R M; Silva, F S

    2015-10-01

    The aim of this work was to study, using the finite element method (FEM), the distribution of thermal residual stresses arising in metal-ceramic dental restorations after cooling from the processing temperature. Three different interface configurations were studied: with conventional sharp transition; one with a 50% metal-50% ceramic interlayer; and one with a compositionally functionally gradated material (FGM) interlayer. The FE analysis was performed based on experimental data obtained from Dynamic Mechanical Analysis (DMA) and Dilatometry (DIL) studies of the monolithic materials and metal/ceramic composites. Results have shown significant benefits of using the 50% metal-50% ceramic interlayer and the FGM interlayer over the conventional sharp transition interface configuration in reduction of the thermal residual stress and improvement of stress profiles. Maximum stresses magnitudes were reduced by 10% for the crowns with 50% metal-50% ceramic interlayer and by 20% with FGM interlayer. The reduction in stress magnitude and smoothness of the stress distribution profile due to the gradated architectures might explain the improved behavior of these novel dental restorative systems relative to the conventional one, demonstrated by in-vitro studies already reported in literature. PMID:26122789

  13. Function of ABA in Stomatal Defense against Biotic and Drought Stresses.

    PubMed

    Lim, Chae Woo; Baek, Woonhee; Jung, Jangho; Kim, Jung-Hyun; Lee, Sung Chul

    2015-01-01

    The plant hormone abscisic acid (ABA) regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses--especially ABA receptors--have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR)/PYR-like (PYL) or regulatory component of ABA receptor (RCAR) family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases. PMID:26154766

  14. Renal Oxidative Stress Induced by Long-Term Hyperuricemia Alters Mitochondrial Function and Maintains Systemic Hypertension

    PubMed Central

    Cristóbal-García, Magdalena; García-Arroyo, Fernando E.; Arellano-Buendía, Abraham S.; Madero, Magdalena; Rodríguez-Iturbe, Bernardo; Pedraza-Chaverrí, José; Zazueta, Cecilia; Johnson, Richard J.; Sánchez Lozada, Laura-Gabriela

    2015-01-01

    We addressed if oxidative stress in the renal cortex plays a role in the induction of hypertension and mitochondrial alterations in hyperuricemia. A second objective was to evaluate whether the long-term treatment with the antioxidant Tempol prevents renal oxidative stress, mitochondrial alterations, and systemic hypertension in this model. Long-term (11-12 weeks) and short-term (3 weeks) effects of oxonic acid induced hyperuricemia were studied in rats (OA, 750 mg/kg BW), OA+Allopurinol (AP, 150 mg/L drinking water), OA+Tempol (T, 15 mg/kg BW), or vehicle. Systolic blood pressure, renal blood flow, and vascular resistance were measured. Tubular damage (urine N-acetyl-β-D-glucosaminidase) and oxidative stress markers (lipid and protein oxidation) along with ATP levels were determined in kidney tissue. Oxygen consumption, aconitase activity, and uric acid were evaluated in isolated mitochondria from renal cortex. Short-term hyperuricemia resulted in hypertension without demonstrable renal oxidative stress or mitochondrial dysfunction. Long-term hyperuricemia induced hypertension, renal vasoconstriction, tubular damage, renal cortex oxidative stress, and mitochondrial dysfunction and decreased ATP levels. Treatments with Tempol and allopurinol prevented these alterations. Renal oxidative stress induced by hyperuricemia promoted mitochondrial functional disturbances and decreased ATP content, which represent an additional pathogenic mechanism induced by chronic hyperuricemia. Hyperuricemia-related hypertension occurs before these changes are evident. PMID:25918583

  15. Perceived stress, reproductive hormones, and ovulatory function: a prospective cohort study

    PubMed Central

    Schliep, Karen C.; Mumford, Sunni L.; Vladutiu, Catherine J.; Ahrens, Katherine A.; Perkins, Neil J.; Sjaarda, Lindsey A.; Kissell, Kerri A.; Prasad, Ankita; Wactawski-Wende, Jean; Schisterman, Enrique F.

    2014-01-01

    Background Stress has been shown to suppress ovulation in experimental models, but its effect on human reproduction at the population level is unclear. Methods Healthy women (n=259), aged 18–44 years from Western New York, were followed for two menstrual cycles (2005–2007). Women completed daily perceived stress assessments, a 4-item Perceived Stress Scale (PSS-4) up to four times each cycle, and a 14-item PSS at baseline. Mixed model analyses were used to assess effects of stress on log reproductive hormone concentrations and sporadic anovulation. Results High versus low daily stress was associated with lower estradiol (-9.5%; 95% confidence interval (CI)= -15.6% to -3.0%), free estradiol (-10.4% [-16.5% to -3.9%]), and LH (-14.8% = [-21.3% to -7.7%]), and higher FSH (6.2% [2.0% to 10.5%]) after adjusting for age, race, percent body fat, depression score, and time-varying hormones and vigorous exercise. High versus low daily stress was also associated with lower luteal progesterone (-10.4% [-19.7% to -0.10%]) and higher odds of anovulation (adjusted OR = 2.2 [95% CI=1.0 to 4.7]). For each unit increase in daily stress level, women had a 70% higher odds of an anovulatory episode (OR=1.7 [1.1 to 2.4]). Similar but attenuated results were found for the association between the PSS-4 and reproductive hormones, while null findings were found for the baseline PSS. Conclusion Daily perceived stress does appear to interfere with menstrual cycle function among women with no known reproductive disorders, warranting further research to explore potential population-level impacts and causal biologic mechanisms. PMID:25643098

  16. Stress and Drug Dependence Differentially Modulate Norepinephrine Signaling in Animals with Varied HPA Axis Function

    PubMed Central

    Fox, Megan E; Studebaker, R Isaac; Swofford, Nathaniel J; Wightman, R Mark

    2015-01-01

    Previous work has demonstrated the importance of genetic factors and stress-sensitive circuits in the development of affective disorders. Anxiety and numerous psychological disorders are comorbid with substance abuse, and noradrenergic signaling in the bed nucleus of the stria terminalis (BNST) is thought to be a source of this convergence. Here, we examined the effects of different stressors on behavior and norepinephrine dynamics in the BNST of rat strains known to differ in their HPA-axis function. We compared the effects of acute morphine dependence and social isolation in non-anxious Sprague Dawley (SD) rats, and a depression model, Wistar-Kyoto (WKY) rats. We found a shared phenotype in drug-dependent and singly housed SD rats, characterized by slowed norepinephrine clearance, decreased autoreceptor function, and elevated anxiety. WKY rats exhibited changes in anxiety and autoreceptor function only following morphine dependence. To ascertain the influence of LC inhibition on this plasticity, we administered the LC-terminal-selective toxin DSP-4 to SD and WKY rats. DSP-4-treated SD rats demonstrated a dependence-like phenotype, whereas WKY rats were unchanged. Overall, our findings suggest that individuals with varying stress susceptibilities have different noradrenergic signaling changes in response to stress. These changes may establish conditions that favor stress-induced reinstatement and increase the risk for addiction. PMID:25601230

  17. Parents of children with haemophilia at an early age: assessment of perceived stress and family functioning.

    PubMed

    Torres-Ortuño, A; Cuesta-Barriuso, R; Nieto-Munuera, J

    2014-11-01

    Haemophilia is a chronic disease that requires a multidisciplinary approach for proper management and control of its clinical manifestations. The perception and management of parents of children with haemophilia can be affected by stressful situations as a result of treatment or disease progression. The aim of this study was to evaluate the perception of stress and family functioning in parents of children with haemophilia 1-7 years. This is an observational clinical study involving 49 parents of children with haemophilia 1-7 years who attended the VIII Workshop for Parents of Children with haemophilia, organized by the Spanish Federation of Hemophilia in La Charca, Murcia (Spain). After obtaining parental consent, the questionnaires was applied to them, FACES III (family functioning) and Pediatric Inventory for Parents (perceived stress), and a record of data on the clinical characteristics and treatment. Significant differences in the perception of stressors by gender of parents were found. A family history of haemophilia, the use of port-a-cath, inhibitor development and gender of the parents were the descriptive variables most correlated with dependents variables. These variables, together with the type of haemophilia affect significantly in the parental stress and family functioning. Parents have difficulty adjusting to disease management, perceiving many stressors. Gender and family history, can hinder the proper compliance with treatments, reducing its effectiveness. PMID:25142950

  18. Posttraumatic Stress Disorder Symptoms and Social and Occupational Functioning of People With Schizophrenia.

    PubMed

    Ng, Lauren C; Petruzzi, Liana J; Greene, M Claire; Mueser, Kim T; Borba, Christina P C; Henderson, David C

    2016-08-01

    This study sought to clarify the contribution of posttraumatic stress disorder (PTSD) to interpersonal and occupational functioning in people with schizophrenia. Self-report questionnaires and semistructured interviews were used to evaluate PTSD and brain injury, positive symptoms, depression, substance abuse, occupational and social functioning, and intelligence. Multiple regressions assessed the relationship between predictors and functional impairment. Posttraumatic stress disorder symptoms were present in 76% of participants, with 12% of participants meeting diagnostic criteria for PTSD. Participants with PTSD had higher rates of depression and more severe positive symptoms. Results of multiple regressions indicated that PTSD symptoms were the only significant predictor of patient-rated interpersonal and occupational functioning. Posttraumatic stress disorder symptoms were not associated with interviewer-rated interpersonal or occupational functioning or employment. While more research is needed, screening and treatment for exposure to traumatic events and PTSD symptoms might be indicated for individuals with schizophrenia. Availability of PTSD assessment and evidence-based treatments for people with schizophrenia is a crucial and often unmet health service need. PMID:27105458

  19. The aftermath of terrorism: posttraumatic stress and functional impairment after the 2011 Oslo bombing

    PubMed Central

    Solberg, Øivind; Blix, Ines; Heir, Trond

    2015-01-01

    Objective: In the present study we wanted to investigate the link between exposure, posttraumatic stress symptomatology, and functional impairment in the aftermath of terrorism. Method: Posttraumatic stress symptomatology and functional impairment related to the Oslo bombing 22nd of July, 2011, in directly and indirectly exposed individuals (N = 1927) were assessed together with demographics, exposure, peri-traumatic reactions, and event centrality approximately 1 year after the attack. Results: Directly and indirectly exposed individuals qualifying for posttraumatic stress disorder (PTSD) reported similar peri-traumatic reactions, event centrality, and functional impairment. However, clusters within the PTSD symptomatology were differentially associated with impairment as a function of their exposure. In the directly exposed group, all clusters within the PTSD symptomatology were associated with impairment in function, while only emotional numbing was associated with impairment within the indirectly exposed group. Conclusion: Considering that terror attacks frequently involve directly exposed individuals and a larger population of indirectly exposed individuals, this finding is of importance, especially in the design of intervention programs and the development of treatment policies. PMID:26300833

  20. Residual stress impairs pump function after surgical ventricular remodeling: A finite element analysis

    PubMed Central

    Pantoja, Joe Luis; Zhang, Zhihong; Tartibi, Mehrzad; Sun, Kay; Macmillan, Warrick; Guccione, Julius M.; Ge, Liang; Ratcliffe, Mark B.

    2016-01-01

    Objectives Surgical ventricular restoration (Dor procedure) is generally thought to reduce left ventricular (LV) myofiber stress (FS) but to adversely affect pump function. However, the underlying mechanism is unclear. The goal of this study was to determine the effect of residual stress (RS) on LV FS and pump function after the Dor procedure. Methods Previously described finite element models of the LV based on MRI data obtained in five sheep 16 weeks after antero-apical myocardial infarction were used. Simulated Dacron patches that were elliptical and 25% of the infarct opening area were implanted using a virtual suture technique (VIRTUAL-DOR). In each case, diastole and systole were simulated and RS, FS, LV volumes, systolic and diastolic function, and pump (Starling) function were calculated. Results VIRTUAL-DOR was associated with significant RS that was tensile (2.89±1.31 kPa) in the remote myocardium and compressive (234.15±65.53 kPa) in the borderzone (BZ). VIRTUAL-DOR+RS (compared to VIRTUAL-DOR-NO-RS) was associated with further reduction in regional diastolic and systolic FS with the greatest change in the BZ (43.5-fold and 7.1-fold respectively, p<0.0001). VIRTUAL-DOR+RS was also associated with further reduction in systolic and diastolic volumes (7.9%, p=0.0606 and 10.6%, p=0.0630, respectively). The resultant effect was a further reduction in pump function after VIRTUAL-DOR+RS. Conclusion Residual stress that occurs after the Dor procedure is positive (tensile) in the remote myocardium and negative (compressive) in the BZ and associated with reductions in fiber stress and LV volumes. The resultant effect is a further reduction in LV pump (Starling) function. PMID:26341601

  1. The relationship between stress and social functioning in adults with autism spectrum disorder and without intellectual disability.

    PubMed

    Bishop-Fitzpatrick, Lauren; Mazefsky, Carla A; Minshew, Nancy J; Eack, Shaun M

    2015-04-01

    Adults with autism spectrum disorder (ASD) face substantial challenges accomplishing basic tasks associated with daily living, which are exacerbated by their broad and pervasive difficulties with social interactions. These challenges put people with ASD at increased risk for psychophysiological distress, which likely factors heavily into social functioning for adults with ASD, as suggested by a growing literature on stress in children that indicates that children with ASD have differential responses to stress than healthy children. We hypothesized that adults with ASD and without intellectual disability (n = 38) would experience more stress than healthy volunteers (n = 37) and that there would be an inverse relationship between stress and social functioning in individuals with ASD. Baseline, semi-structured interview data from a randomized controlled trial of two treatments for adults with ASD were used to assess differences in stress between adults with ASD and healthy volunteers and to assess the relationship between stress response and social functioning in adults with ASD. Findings indicate that adults with ASD experience greater perceived and interviewer-observed stress than healthy volunteers and that stress is significantly related to social functioning in adults with ASD. These findings highlight the role of stress in adult functioning and outcomes and suggest the need to develop and assess treatments designed to target stress and coping in adults with ASD. PMID:25524571

  2. Fetal programming of hypothalamo-pituitary-adrenal function: prenatal stress and glucocorticoids

    PubMed Central

    Kapoor, Amita; Dunn, Elizabeth; Kostaki, Alice; Andrews, Marcus H; Matthews, Stephen G

    2006-01-01

    Prenatal stress (PS) and maternal exposure to exogenous glucocorticoids can lead to permanent modification of hypothalamo-pituitary-adrenal (HPA) function and stress-related behaviour. Both of these manipulations lead to increased fetal exposure to glucocorticoids. Glucocorticoids are essential for many aspects of normal brain development, but exposure of the fetal brain to an excess of glucocorticoids can have life-long effects on neuroendocrine function. Both endogenous glucocorticoid and synthetic glucocorticoid exposure have a number of rapid effects in the fetal brain, including modification of neurotransmitter systems and transcriptional machinery. Such fetal exposure permanently alters HPA function in prepubertal, postpubertal and ageing offspring, in a sex-dependent manner. Prenatal stress and exogenous glucocorticoid manipulation also lead to the modification of behaviour, brain and organ morphology, as well as altered regulation of other endocrine systems. It is also becoming increasingly apparent that the timing of exposure to PS or synthetic glucocorticoids has tremendous effects on the nature of the phenotypic outcome. Permanent changes in endocrine function will ultimately impact on health in both human and animal populations. PMID:16469780

  3. NEUROENDOCRINE FUNCTIONS OF PUERPERAE WITH POSTPARTUM DEPRESSION AGGRAVATED BY STRESSFUL CHILDBIRTH-RELATED EVENTS.

    PubMed

    Song, W; Yu, S

    2015-01-01

    In the period of gestation, delivery and post-delivery, fear and tension produced in puerperae are likely to evolve into depression as they worry too much about delivery pain. In recent years, it has been noted that stressful events during this period aggravate postpartum depression. To discuss the effect of these childbirth-related stressful events on neuroendocrine functions of patients with postpartum depression, 300 full-term puerperae who had been admitted to the Beijing Obstetrics and Gynecology Hospital, Capital Medical University between October, 2011 and October, 2013 and who had suffered from stressful childbirth-related events were enrolled as a study group. This group was divided into six subgroups, i.e., A, B, C, D, E and F, based on the number of stressful events they had suffered which were labeled by numbers 1 to 6. Additionally, 100 puerperae from the same hospital who had not suffered from childbirth-related stressful events were taken as controls. Relevant clinical indexes, including serum adrenocorticotropic hormone (ACTH), plasma 5-hydroxytryptamine (5-HT), noradrenaline ELISA (NE), dopamine (DA) and cortisol level were measured and compared. It was found that incidence probability of postpartum depression was significantly different between the study group (13.67%, 41/300) and the control group (7%, 7/100). Moreover, the incidence probability of postpartum depression of puerperae suffering from no less than 4 childbirth-related stressful events was higher than those suffering from no more than 3, and the difference was statistically significant (P<0.05). Thus, stress disorders caused by these events are one of the important pathogenic factors of postpartum depression. PMID:26403408

  4. Oxidative stress and bioindicators of reproductive function in pulp and paper mill effluent exposed white sucker.

    PubMed

    Oakes, Ken D; McMaster, Mark E; Pryce, Andrea C; Munkittrick, Kelly R; Portt, Cam B; Hewitt, L Mark; MacLean, Dan D; Van Der Kraak, Glen J

    2003-07-01

    This study investigates oxidative stress and bioindicators of reproductive function in wild white sucker (Catostomus commersoni) collected from environments receiving pulp and paper mill effluent discharges in northern Ontario. Samples were collected over an eight-year period adjacent to three pulp and paper mills using a variety of processing and bleaching techniques. Fish collected downstream of pulp and paper mills within the Moose River basin exhibited elevated hepatic and gonadal 2-thiobarbituric acid reactive substances (TBARS), the presence of which is indicative of oxidative stress in these tissues. Within the Jackfish Bay system, exposure to pulp and paper mill effluent did not elevate hepatic or gonadal TBARS. Hepatic cytochrome P4501A activity (CYP1A) and fatty acyl-CoA oxidase (FAO) activities were frequently increased in livers of Moose River basin fish exposed to pulp and paper mill effluent, while lower activities of both enzymes were found within fish from the Jackfish Bay system. This suggests that oxidative stress may be related to CYP1A and FAO activities. Within the Moose River system, increases in measures of oxidative stress (TBARS, FAO) were generally coincident with decreased levels of 17 beta-estradiol; however, testosterone was often lower in Jackfish Bay system fish without any commensurate changes in oxidative stress. The suite of reproductive and oxidative stress parameters measured in this study varied between seasons and mills suggesting responses to effluent are dynamic and effects are complicated by different receiving environments. The relationship between gonad size, gonadal oxidative stress, and circulating plasma steroids remains unclear. PMID:12730610

  5. Genetic variation in cortico-amygdala serotonin function and risk for stress-related disease

    PubMed Central

    Holmes, Andrew

    2008-01-01

    The serotonin system is strongly implicated in the pathophysiology and therapeutic alleviation of stress-related disorders such as anxiety and depression. Serotonergic modulation of the acute response to stress and the adaptation to chronic stress is mediated by a myriad of molecules controlling serotonin neuron development (Pet-1), synthesis (tryptophan hydroxylase 1 and 2 isozymes), packaging (vesicular monoamine transporter 2), actions at presynaptic and postsynaptic receptors (5-HT1A, 5-HT1B, 5-HT2A, 5-HT2C, 5-HT3A, 5-HT4, 5-HT5A, 5-HT6, 5-HT7), reuptake (serotonin transporter), and degradation (monoamine oxidase A). A growing body of evidence from preclinical rodents models, and especially genetically modified mice and inbred mouse strains, has provided significant insight into how genetic variation in these molecules can affect the development and function of a key neural circuit between the dorsal raphe nucleus, medial prefrontal cortex and amygdala. By extension, such variation is hypothesized to have a major influence on individual differences in the stress response and risk for stress-related disease in humans. The current article provides an update on this rapidly evolving field of research. PMID:18439676

  6. Development of accumulated heat stress index based on time-weighted function

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Sun; Byun, Hi-Ryong; Kim, Do-Woo

    2016-05-01

    Heat stress accumulates in the human body when a person is exposed to a thermal condition for a long time. Considering this fact, we have defined the accumulated heat stress (AH) and have developed the accumulated heat stress index (AHI) to quantify the strength of heat stress. AH represents the heat stress accumulated in a 72-h period calculated by the use of a time-weighted function, and the AHI is a standardized index developed by the use of an equiprobability transformation (from a fitted Weibull distribution to the standard normal distribution). To verify the advantage offered by the AHI, it was compared with four thermal indices the humidex, the heat index, the wet-bulb globe temperature, and the perceived temperature used by national governments. AH and the AHI were found to provide better detection of thermal danger and were more useful than other indices. In particular, AH and the AHI detect deaths that were caused not only by extremely hot and humid weather, but also by the persistence of moderately hot and humid weather (for example, consecutive daily maximum temperatures of 28-32 °C), which the other indices fail to detect.

  7. Conserved cellular function and stress-mediated regulation among members of the proteolipid protein family.

    PubMed

    Fernández, María E; Alfonso, Julieta; Brocco, Marcela A; Frasch, Alberto C

    2010-05-01

    Chronic stress causes morphological alterations in the hippocampus of rodents and tree shrews, including atrophy of CA3 dendrites and loss of synapses. The molecular mechanisms underlying these structural changes remain largely unknown. We have previously identified M6a as a stress responsive gene and shown that M6a is involved in filopodium/spine outgrowth and, likely, synapse formation. M6a belongs to the proteolipid protein (PLP) family, all of their members having four transmembrane domains that allow their localization at the plasma membrane. In the present work, we analyzed other members of this family, the closely related M6b as well as PLP and its splice variant DM20. We found that chronic restraint stress in mice reduces M6b and DM20, but not PLP, mRNA levels in the hippocampus. In addition, M6b and DM20, but again not PLP, induce filopodium formation in primary cultures of hippocampal neurons. Several M6b protein isoforms were studied, all of them having similar effects except for the one lacking the transmembrane domains. Our results reveal a conserved cellular function and a stress-mediated regulation among members of the proteolipid protein family, suggesting an involvement of proteolipid proteins in the stress response. PMID:19937804

  8. Development of accumulated heat stress index based on time-weighted function

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Sun; Byun, Hi-Ryong; Kim, Do-Woo

    2015-04-01

    Heat stress accumulates in the human body when a person is exposed to a thermal condition for a long time. Considering this fact, we have defined the accumulated heat stress (AH) and have developed the accumulated heat stress index (AHI) to quantify the strength of heat stress. AH represents the heat stress accumulated in a 72-h period calculated by the use of a time-weighted function, and the AHI is a standardized index developed by the use of an equiprobability transformation (from a fitted Weibull distribution to the standard normal distribution). To verify the advantage offered by the AHI, it was compared with four thermal indices the humidex, the heat index, the wet-bulb globe temperature, and the perceived temperature used by national governments. AH and the AHI were found to provide better detection of thermal danger and were more useful than other indices. In particular, AH and the AHI detect deaths that were caused not only by extremely hot and humid weather, but also by the persistence of moderately hot and humid weather (for example, consecutive daily maximum temperatures of 28-32 °C), which the other indices fail to detect.

  9. Gene mining in halophytes: functional identification of stress tolerance genes in Lepidium crassifolium.

    PubMed

    Rigó, Gábor; Valkai, Ildikó; Faragó, Dóra; Kiss, Edina; Van Houdt, Sara; Van de Steene, Nancy; Hannah, Matthew A; Szabados, László

    2016-09-01

    Extremophile plants are valuable sources of genes conferring tolerance traits, which can be explored to improve stress tolerance of crops. Lepidium crassifolium is a halophytic relative of the model plant Arabidopsis thaliana, and displays tolerance to salt, osmotic and oxidative stresses. We have employed the modified Conditional cDNA Overexpression System to transfer a cDNA library from L. crassifolium to the glycophyte A. thaliana. By screening for salt, osmotic and oxidative stress tolerance through in vitro growth assays and non-destructive chlorophyll fluorescence imaging, 20 Arabidopsis lines were identified with superior performance under restrictive conditions. Several cDNA inserts were cloned and confirmed to be responsible for the enhanced tolerance by analysing independent transgenic lines. Examples include full-length cDNAs encoding proteins with high homologies to GDSL-lipase/esterase or acyl CoA-binding protein or proteins without known function, which could confer tolerance to one or several stress conditions. Our results confirm that random gene transfer from stress tolerant to sensitive plant species is a valuable tool to discover novel genes with potential for biotechnological applications. PMID:27343166

  10. Left ventricular systolic function during stress echocardiography exercise in subjects with asymptomatic hereditary hemochromatosis.

    PubMed

    Shizukuda, Yukitaka; Bolan, Charles D; Tripodi, Dorothy J; Yau, Yu-Ying; Smith, Kevin P; Sachdev, Vandana; Birdsall, Charles W; Sidenko, Stanislav; Waclawiw, Myron A; Leitman, Susan F; Rosing, Douglas R

    2006-09-01

    There is no information available on left ventricular (LV) systolic function and the response to stress echocardiography in asymptomatic subjects with hereditary hemochromatosis (HH). To evaluate this topic, 43 asymptomatic subjects with HH homozygous for the C282Y HFE gene mutation (22 untreated subjects [group A] and 21 long-term treated subjects [group B]) were compared with 21 age- and gender-matched normal volunteers negative for HFE mutations. Contractile reserve, as a measure of LV systolic function, was assessed using continuous echocardiographic imaging and electrocardiography during supine bicycle exercise. Nineteen subjects in group A had repeat tests after 6 months of induction phlebotomy therapy to assess the effect of iron removal. Exercise performance and hemodynamic variables of supine bicycle exercise were comparable between subjects with HH and controls. LV contractile reserve of asymptomatic subjects with HH was not impaired at either a 75-W submaximal exercise level (mean +/- SD difference in ejection fraction from baseline 13.8 +/- 6.2%, 11.5 +/- 6.8%, and 13.4 +/- 7.8% in groups A, B, and C, respectively; p = NS for all by analysis of variance) or at peak exercise (difference in ejection fraction from baseline 18.9 +/- 6.9%, 18.4 +/- 7.8%, and 20.3 +/- 8.1% in groups A, B, and C, respectively; p = NS for all by analysis of variance). However, the incidence of abnormal ischemic stress electrocardiographic responses was more frequent in subjects with HH as a whole (33%) compared with normal subjects (10%). Stress imaging revealed no regional wall motion abnormalities, suggesting that these were false-positive results. Iron removal by induction phlebotomy did not affect stress echocardiographic performance. In conclusion, LV systolic function during exercise in asymptomatic subjects with HH is preserved, and 6-month induction phlebotomy does not affect stress echocardiographic performance. PMID:16923464

  11. Increased Oxidative Stress Impairs Adipose Tissue Function in Sphingomyelin Synthase 1 Null Mice

    PubMed Central

    Nishimura, Naotaka; Gotoh, Tomomi; Watanabe, Ken; Ikeda, Kazutaka; Garan, Yohei; Taguchi, Ryo; Node, Koichi; Okazaki, Toshiro; Oike, Yuichi

    2013-01-01

    Sphingomyelin synthase 1 (SMS1) catalyzes the conversion of ceramide to sphingomyelin. Here, we found that SMS1 null mice showed lipodystrophic phenotype. Mutant mice showed up-regulation of plasma triglyceride concentrations accompanied by reduction of white adipose tissue (WAT) as they aged. Lipoprotein lipase (LPL) activity was severely reduced in mutant mice. In vivo analysis indicated that fatty acid uptake in WAT but not in liver decreased in SMS1 null compared to wild-type mice. In vitro analysis using cultured cell revealed that SMS1 depletion reduced fatty acid uptake. Proteins extracted from WAT of mutant mice were severely modified by oxidative stress, and up-regulation of mRNAs related to apoptosis, redox adjustment, mitochondrial stress response and mitochondrial biogenesis was observed. ATP content of WAT was reduced in SMS1 null mice. Blue native gel analysis indicated that accumulation of mitochondrial respiratory chain complexes was reduced. These results suggest that WAT of SMS1 null mice is severely damaged by oxidative stress and barely functional. Indeed, mutant mice treated with the anti-oxidant N-acetyl cysteine (NAC) showed partial recovery of lipodystrophic phenotypes together with normalized plasma triglyceride concentrations. Altogether, our data suggest that SMS1 is crucial to control oxidative stress in order to maintain WAT function. PMID:23593476

  12. Increased oxidative stress impairs adipose tissue function in sphingomyelin synthase 1 null mice.

    PubMed

    Yano, Masato; Yamamoto, Tadashi; Nishimura, Naotaka; Gotoh, Tomomi; Watanabe, Ken; Ikeda, Kazutaka; Garan, Yohei; Taguchi, Ryo; Node, Koichi; Okazaki, Toshiro; Oike, Yuichi

    2013-01-01

    Sphingomyelin synthase 1 (SMS1) catalyzes the conversion of ceramide to sphingomyelin. Here, we found that SMS1 null mice showed lipodystrophic phenotype. Mutant mice showed up-regulation of plasma triglyceride concentrations accompanied by reduction of white adipose tissue (WAT) as they aged. Lipoprotein lipase (LPL) activity was severely reduced in mutant mice. In vivo analysis indicated that fatty acid uptake in WAT but not in liver decreased in SMS1 null compared to wild-type mice. In vitro analysis using cultured cell revealed that SMS1 depletion reduced fatty acid uptake. Proteins extracted from WAT of mutant mice were severely modified by oxidative stress, and up-regulation of mRNAs related to apoptosis, redox adjustment, mitochondrial stress response and mitochondrial biogenesis was observed. ATP content of WAT was reduced in SMS1 null mice. Blue native gel analysis indicated that accumulation of mitochondrial respiratory chain complexes was reduced. These results suggest that WAT of SMS1 null mice is severely damaged by oxidative stress and barely functional. Indeed, mutant mice treated with the anti-oxidant N-acetyl cysteine (NAC) showed partial recovery of lipodystrophic phenotypes together with normalized plasma triglyceride concentrations. Altogether, our data suggest that SMS1 is crucial to control oxidative stress in order to maintain WAT function. PMID:23593476

  13. GABAergic regulation of the HPA and HPG axes and the impact of stress on reproductive function.

    PubMed

    Camille Melón, Laverne; Maguire, Jamie

    2016-06-01

    The hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes are regulated by GABAergic signaling at the level of corticotropin-releasing hormone (CRH) and gonadotropin-releasing hormone (GnRH) neurons, respectively. Under basal conditions, activity of CRH and GnRH neurons are controlled in part by both phasic and tonic GABAergic inhibition, mediated by synaptic and extrasynaptic GABAA receptors (GABAARs), respectively. For CRH neurons, this tonic GABAergic inhibition is mediated by extrasynaptic, δ subunit-containing GABAARs. Similarly, a THIP-sensitive tonic GABAergic current has been shown to regulate GnRH neurons, suggesting a role for δ subunit-containing GABAARs; however, this remains to be explicitly demonstrated. GABAARs incorporating the δ subunit confer neurosteroid sensitivity, suggesting a potential role for neurosteroid modulation in the regulation of the HPA and HPG axes. Thus, stress-derived neurosteroids may contribute to the impact of stress on reproductive function. Interestingly, excitatory actions of GABA have been demonstrated in both CRH neurons at the apex of control of the HPA axis and in GnRH neurons which mediate the HPG axis, adding to the complexity for the role of GABAergic signaling in the regulation of these systems. Here we review the effects that stress has on GnRH neurons and HPG axis function alongside evidence supporting GABAARs as a major interface between the stress and reproductive axes. PMID:26690789

  14. Global functions in global-local finite-element analysis of localized stresses in prismatic structures

    NASA Technical Reports Server (NTRS)

    Dong, Stanley B.

    1989-01-01

    An important consideration in the global local finite-element method (GLFEM) is the availability of global functions for the given problem. The role and mathematical requirements of these global functions in a GLFEM analysis of localized stress states in prismatic structures are discussed. A method is described for determining these global functions. Underlying this method are theorems due to Toupin and Knowles on strain energy decay rates, which are related to a quantitative expression of Saint-Venant's principle. It is mentioned that a mathematically complete set of global functions can be generated, so that any arbitrary interface condition between the finite element and global subregions can be represented. Convergence to the true behavior can be achieved with increasing global functions and finite-element degrees of freedom. Specific attention is devoted to mathematically two-dimensional and three-dimensional prismatic structures. Comments are offered on the GLFEM analysis of NASA flat panel with a discontinuous stiffener. Methods for determining global functions for other effects are also indicated, such as steady-state dynamics and bodies under initial stress.

  15. Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats.

    PubMed

    Ortiz-Avila, Omar; Esquivel-Martínez, Mauricio; Olmos-Orizaba, Berenice Eridani; Saavedra-Molina, Alfredo; Rodriguez-Orozco, Alain R; Cortés-Rojo, Christian

    2015-01-01

    Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨ m ), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress. PMID:26180820

  16. Glycolytic Enzymes Localize to Synapses under Energy Stress to Support Synaptic Function.

    PubMed

    Jang, SoRi; Nelson, Jessica C; Bend, Eric G; Rodríguez-Laureano, Lucelenie; Tueros, Felipe G; Cartagenova, Luis; Underwood, Katherine; Jorgensen, Erik M; Colón-Ramos, Daniel A

    2016-04-20

    Changes in neuronal activity create local and transient changes in energy demands at synapses. Here we discover a metabolic compartment that forms in vivo near synapses to meet local energy demands and support synaptic function in Caenorhabditis elegans neurons. Under conditions of energy stress, glycolytic enzymes redistribute from a diffuse localization in the cytoplasm to a punctate localization adjacent to synapses. Glycolytic enzymes colocalize, suggesting the ad hoc formation of a glycolysis compartment, or a "glycolytic metabolon," that can maintain local levels of ATP. Local formation of the glycolytic metabolon is dependent on presynaptic scaffolding proteins, and disruption of the glycolytic metabolon blocks the synaptic vesicle cycle, impairs synaptic recovery, and affects locomotion. Our studies indicate that under energy stress conditions, energy demands in C. elegans synapses are met locally through the assembly of a glycolytic metabolon to sustain synaptic function and behavior. VIDEO ABSTRACT. PMID:27068791

  17. Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats

    PubMed Central

    Ortiz-Avila, Omar; Esquivel-Martínez, Mauricio; Olmos-Orizaba, Berenice Eridani; Saavedra-Molina, Alfredo; Rodriguez-Orozco, Alain R.; Cortés-Rojo, Christian

    2015-01-01

    Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨm), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress. PMID:26180820

  18. An approximate solution to the stress and deformation states of functionally graded rotating disks

    NASA Astrophysics Data System (ADS)

    Sondhi, Lakshman; Sanyal, Shubhashis; Saha, Kashi Nath; Bhowmick, Shubhankar

    2016-07-01

    The present work employs variational principle to investigate the stress and deformation states and estimate the limit angular speed of functionally graded high-speed rotating annular disks of constant thickness. Assuming a series approximation following Galerkin's principle, the solution of the governing equation is obtained. In the present study, elasticity modulus and density of the disk material are taken as power function of radius with the gradient parameter ranging between 0.0 and 1.0. Results obtained from numerical solutions are validated with benchmark results and are found to be in good agreement. The results are reported in dimensional form and presented graphically. The results provide a substantial insight in understanding the behavior of FGM rotating disks with constant thickness and different gradient parameter. Furthermore, the stress and deformation state of the disk at constant angular speed and limit angular speed is investigated to explain the existence of optimum gradient parameters.

  19. Analysis of stress singularities at singular points of elastic solids made of functionally graded materials

    NASA Astrophysics Data System (ADS)

    Matveenko, V. P.; Fedorov, A. Yu.; Shardakov, I. N.

    2016-01-01

    The results of analytical and numerical investigations on estimating the character of the singularity of stresses in a vicinity of different variants of special points of the 2D elastic solids made of functionally graded materials (FGMs) are presented. The variant of construction by analytical methods in the polar system of coordinates is considered for eigensolutions in the flat wedges made of the FGM, the elastic properties of which are represented as power series in terms of the radial coordinate.

  20. Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1973-01-01

    Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.

  1. Alternative splicing of Drosophila Nmnat functions as a switch to enhance neuroprotection under stress

    PubMed Central

    Ruan, Kai; Zhu, Yi; Li, Chong; Brazill, Jennifer M.; Zhai, R. Grace

    2015-01-01

    Nicotinamide mononucleotide adenylyltransferase (NMNAT) is a conserved enzyme in the NAD synthetic pathway. It has also been identified as an effective and versatile neuroprotective factor. However, it remains unclear how healthy neurons regulate the dual functions of NMNAT and achieve self-protection under stress. Here we show that Drosophila Nmnat (DmNmnat) is alternatively spliced into two mRNA variants, RA and RB, which translate to protein isoforms with divergent neuroprotective capacities against spinocerebellar ataxia 1-induced neurodegeneration. Isoform PA/PC translated from RA is nuclear-localized with minimal neuroprotective ability, and isoform PB/PD translated from RB is cytoplasmic and has robust neuroprotective capacity. Under stress, RB is preferably spliced in neurons to produce the neuroprotective PB/PD isoforms. Our results indicate that alternative splicing functions as a switch that regulates the expression of functionally distinct DmNmnat variants. Neurons respond to stress by driving the splicing switch to produce the neuroprotective variant and therefore achieve self-protection. PMID:26616331

  2. Family Stress and Adolescents’ Cognitive Functioning: Sleep as a Protective Factor

    PubMed Central

    El-Sheikh, Mona; Tu, Kelly M.; Erath, Stephen A.; Buckhalt, Joseph A.

    2014-01-01

    We examined two sleep-wake parameters as moderators of the associations between exposure to family stressors and adolescent cognitive functioning. Participants were 252 school-recruited adolescents (M = 15.79 years; 66% European American, 34% African American). Youths reported on three dimensions of family stress: marital conflict, harsh parenting, and parental psychological control. Cognitive functioning was indexed through performance on the Woodcock-Johnson III Tests of Cognitive Abilities. Sleep minutes and efficiency were measured objectively using actigraphy. Towards identifying unique effects, path models controlled for two family stress variables while estimating the third. Analyses revealed that sleep efficiency moderated the associations between negative parenting (harsh parenting and parental psychological control) and adolescents’ cognitive functioning. The highest level of cognitive performance was predicted for adolescents with higher levels of sleep efficiency in conjunction with lower levels of either harsh parenting or psychological control. The effects of sleep were more pronounced at lower levels of negative parenting where adolescents with higher sleep efficiency performed better than their counterparts with poorer sleep. At higher levels of either harsh parenting or psychological control, similar levels of cognitive performance were observed regardless of sleep. Results are discussed in comparison to other recent studies on interrelations among family stress, sleep, and cognitive performance in childhood and adolescence. PMID:25329625

  3. Replication stress is a potent driver of functional decline in ageing haematopoietic stem cells

    PubMed Central

    Flach, Johanna; Bakker, Sietske T.; Mohrin, Mary; Conroy, Pauline C.; Pietras, Eric M.; Reynaud, Damien; Alvarez, Silvia; Diolaiti, Morgan E.; Ugarte, Fernando; Forsberg, E. Camilla; Le Beau, Michelle M.; Stohr, Bradley A.; Méndez, Juan; Morrison, Ciaran G.; Passegué, Emmanuelle

    2015-01-01

    Haematopoietic stem cells (HSCs) self-renew for life, thereby making them one of the few blood cells that truly age1,2. Paradoxically, although HSCs numerically expand with age, their functional activity declines over time, resulting in degraded blood production and impaired engraftment following transplantation2. While many drivers of HSC ageing have been proposed2–5, the reason why HSC function degrades with age remains unknown. Here we show that cycling old HSCs in mice have heightened levels of replication stress associated with cell cycle defects and chromosome gaps or breaks, which are due to decreased expression of mini-chromosome maintenance (MCM) helicase components and altered dynamics of DNA replication forks. Nonetheless, old HSCs survive replication unless confronted with a strong replication challenge, such as transplantation. Moreover, once old HSCs re-establish quiescence, residual replication stress on ribosomal DNA (rDNA) genes leads to the formation of nucleolar-associated γH2AX signals, which persist owing to ineffective H2AX dephosphorylation by mislocalized PP4c phosphatase rather than ongoing DNA damage. Persistent nucleolar γH2AX also acts as a histone modification marking the transcriptional silencing of rDNA genes and decreased ribosome biogenesis in quiescent old HSCs. Our results identify replication stress as a potent driver of functional decline in old HSCs, and highlight the MCM DNA helicase as a potential molecular target for rejuvenation therapies. PMID:25079315

  4. Diosmin pretreatment improves cardiac function and suppresses oxidative stress in rat heart after ischemia/reperfusion.

    PubMed

    Senthamizhselvan, Oomaidurai; Manivannan, Jeganathan; Silambarasan, Thangarasu; Raja, Boobalan

    2014-08-01

    Reperfusion of ischemic tissue leads to the generation of oxygen derived free radicals which plays an important role in cellular damage. Objective of the current study is to evaluate the cardio-protective and antioxidant effect of diosmin on ischemia-reperfusion related cardiac dysfunction, oxidative stress and apoptosis. Diosmin (50 and 100 mg/kg body weight (bw)) was given every day to the rats orally throughout the experimental period. Ischemia/reperfusion protocol was carried out ex vivo using langendorff perfusion method and the cardiac functional recovery was assessed in terms of percentage rate pressure product. Coronary effluents of LDH and CK-MB activities, antioxidant enzyme activities, lipid peroxidation products, activity of TCA cycle enzymes were evaluated. Moreover, in vitro superoxide anion and hydroxyl radical scavenging potential of diosmin was also quantified. Finally, quantitative real-time PCR was used for assessing Bcl-2 mRNA expression in heart. Cardiac functional recovery was impaired after reperfusion compared with continuously perfused heart. It was significantly prevented by diosmin treatment. Impaired antioxidant enzyme activities and elevated lipid peroxidation products level were also significantly suppressed. The activity of TCA cycle enzymes was protected against reperfusion stress. Down regulated Bcl-2 was also significantly increased. This study concluded that diosmin pretreatment prevents all the impaired patterns including cardiac function, oxidative stress and apoptosis associated with reperfusion in control heart by its antioxidant role. PMID:24769512

  5. One-Dimensional Solutions for Transient Thermal Stresses in Functionally Graded Hollow Cylinders and Hollow Spheres

    NASA Astrophysics Data System (ADS)

    Ootao, Yoshihiro; Tanigawa, Yoshinobu

    2008-02-01

    This paper is concerned with the theoretical treatment of transient thermoelastic problems involving functionally graded hollow cylinders and hollow spheres due to uniform heat supply. The thermal and thermoelastic coefficients of the hollow cylinders and hollow spheres are expressed as power functions of the radial coordinate. The one-dimensional solutions for the temperature changes in a transient state and the thermoelastic response are obtained herein. Some numerical results are shown in figures. Furthermore, the influence of the material nonhomogeneity on the temperature change, displacements and stresses is investigated.

  6. Thermoelastic Stress in a Functionally Graded Infinite Plate with Electromagnetic Wave Absorption

    NASA Astrophysics Data System (ADS)

    Tian, Hong-Yan; Wang, Xing-Zhe; Zhou, You-He

    2012-11-01

    We present an analysis of thermal and thermoelastic behaviors of a functionally graded infinite plate taking into account electromagnetic wave absorption. To treat with the inhomogeneity of functionally graded wave-absorbing (FGWA) materials, the plate is approximated by subdividing it into thin homogeneous layers to solve the governing equations together with proper boundary and connecting conditions. The results illustrate that the FGWA plate is a broadband type absorber with electromagnetic wave absorption. By choosing proper material gradation character and the thickness of the FGWA plate, it is possible to obtain a good performance of electromagnetic wave absorption and thermoelastic stress characteristics.

  7. Engineering deceleration and acceleration of soliton emitted from Airy pulse with quadratic phase modulation in optical fibers without high-order effects

    NASA Astrophysics Data System (ADS)

    Zhang, Lifu; Liu, Kun; Zhong, Haizhe; Zhang, Jinggui; Deng, Jianqin; Li, Ying; Fan, Dianyuan

    2015-07-01

    Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. We show that, under the action of the anomalous second-order dispersion (SOD) and Kerr nonlinearity, Airy pulse with QPM is able to emit soliton with acceleration or deceleration depending on whether the QPM is negative or positive, and at a rate that is determined by the magnitude of QPM. The reason is that the acceleration behaviors of incident Airy pulse is altered depending on whether SOD and QPM have the same or opposite signs. Our study shows the possibility of controlling and manipulating the soliton propagation and interaction in optical fibers without HOEs, by purposely choosing appropriate QPM parameter of an Airy pulse.

  8. Engineering deceleration and acceleration of soliton emitted from Airy pulse with quadratic phase modulation in optical fibers without high-order effects.

    PubMed

    Zhang, Lifu; Liu, Kun; Zhong, Haizhe; Zhang, Jinggui; Deng, Jianqin; Li, Ying; Fan, Dianyuan

    2015-01-01

    Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. We show that, under the action of the anomalous second-order dispersion (SOD) and Kerr nonlinearity, Airy pulse with QPM is able to emit soliton with acceleration or deceleration depending on whether the QPM is negative or positive, and at a rate that is determined by the magnitude of QPM. The reason is that the acceleration behaviors of incident Airy pulse is altered depending on whether SOD and QPM have the same or opposite signs. Our study shows the possibility of controlling and manipulating the soliton propagation and interaction in optical fibers without HOEs, by purposely choosing appropriate QPM parameter of an Airy pulse. PMID:26173387

  9. Functional annotation of the transcriptome of Sorghum bicolor in response to osmotic stress and abscisic acid

    PubMed Central

    2011-01-01

    Background Higher plants exhibit remarkable phenotypic plasticity allowing them to adapt to an extensive range of environmental conditions. Sorghum is a cereal crop that exhibits exceptional tolerance to adverse conditions, in particular, water-limiting environments. This study utilized next generation sequencing (NGS) technology to examine the transcriptome of sorghum plants challenged with osmotic stress and exogenous abscisic acid (ABA) in order to elucidate genes and gene networks that contribute to sorghum's tolerance to water-limiting environments with a long-term aim of developing strategies to improve plant productivity under drought. Results RNA-Seq results revealed transcriptional activity of 28,335 unique genes from sorghum root and shoot tissues subjected to polyethylene glycol (PEG)-induced osmotic stress or exogenous ABA. Differential gene expression analyses in response to osmotic stress and ABA revealed a strong interplay among various metabolic pathways including abscisic acid and 13-lipoxygenase, salicylic acid, jasmonic acid, and plant defense pathways. Transcription factor analysis indicated that groups of genes may be co-regulated by similar regulatory sequences to which the expressed transcription factors bind. We successfully exploited the data presented here in conjunction with published transcriptome analyses for rice, maize, and Arabidopsis to discover more than 50 differentially expressed, drought-responsive gene orthologs for which no function had been previously ascribed. Conclusions The present study provides an initial assemblage of sorghum genes and gene networks regulated by osmotic stress and hormonal treatment. We are providing an RNA-Seq data set and an initial collection of transcription factors, which offer a preliminary look into the cascade of global gene expression patterns that arise in a drought tolerant crop subjected to abiotic stress. These resources will allow scientists to query gene expression and functional

  10. Oxidative Stress Induces Caveolin 1 Degradation and Impairs Caveolae Functions in Skeletal Muscle Cells

    PubMed Central

    Mougeolle, Alexis; Poussard, Sylvie; Decossas, Marion; Lamaze, Christophe

    2015-01-01

    Increased level of oxidative stress, a major actor of cellular aging, impairs the regenerative capacity of skeletal muscle and leads to the reduction in the number and size of muscle fibers causing sarcopenia. Caveolin 1 is the major component of caveolae, small membrane invaginations involved in signaling and endocytic trafficking. Their role has recently expanded to mechanosensing and to the regulation of oxidative stress-induced pathways. Here, we increased the amount of reactive oxidative species in myoblasts by addition of hydrogen peroxide (H2O2) at non-toxic concentrations. The expression level of caveolin 1 was significantly decreased as early as 10 min after 500 μM H2O2 treatment. This reduction was not observed in the presence of a proteasome inhibitor, suggesting that caveolin 1 was rapidly degraded by the proteasome. In spite of caveolin 1 decrease, caveolae were still able to assemble at the plasma membrane. Their functions however were significantly perturbed by oxidative stress. Endocytosis of a ceramide analog monitored by flow cytometry was significantly diminished after H2O2 treatment, indicating that oxidative stress impaired its selective internalization via caveolae. The contribution of caveolae to the plasma membrane reservoir has been monitored after osmotic cell swelling. H2O2 treatment increased membrane fragility revealing that treated cells were more sensitive to an acute mechanical stress. Altogether, our results indicate that H2O2 decreased caveolin 1 expression and impaired caveolae functions. These data give new insights on age-related deficiencies in skeletal muscle. PMID:25799323

  11. Maternal stress, nutrition and physical activity: Impact on immune function, CNS development and psychopathology.

    PubMed

    Marques, Andrea Horvath; Bjørke-Monsen, Anne-Lise; Teixeira, Antônio L; Silverman, Marni N

    2015-08-18

    Evidence suggests that maternal and fetal immune dysfunction may impact fetal brain development and could play a role in neurodevelopmental disorders, although the definitive pathophysiological mechanisms are still not completely understood. Stress, malnutrition and physical inactivity are three maternal behavioral lifestyle factors that can influence immune and central nervous system (CNS) functions in both the mother and fetus, and may therefore, increase risk for neurodevelopmental/psychiatric disorders. First, we will briefly review some aspects of maternal-fetal immune system interactions and development of immune tolerance. Second, we will discuss the bidirectional communication between the immune system and CNS and the pathways by which immune dysfunction could contribute to neurodevelopmental disorders. Third, we will discuss the effects of prenatal stress and malnutrition (over and undernutrition) on perinatal programming of the CNS and immune system, and how this might influence neurodevelopment. Finally, we will discuss the beneficial impact of physical fitness during pregnancy on the maternal-fetal unit and infant and how regular physical activity and exercise can be an effective buffer against stress- and inflammatory-related disorders. Although regular physical activity has been shown to promote neuroplasticity and an anti-inflammatory state in the adult, there is a paucity of studies evaluating its impact on CNS and immune function during pregnancy. Implementing stress reduction, proper nutrition and ample physical activity during pregnancy and the childbearing period may be an efficient strategy to counteract the impact of maternal stress and malnutrition/obesity on the developing fetus. Such behavioral interventions could have an impact on early development of the CNS and immune system and contribute to the prevention of neurodevelopmental and psychiatric disorders. Further research is needed to elucidate this relationship and the underlying

  12. [Effects of exogenous spermidine on mitochondrial function of tomato seedling roots under salinity-alkalinity stress].

    PubMed

    Pan, Xiong-bo; Xiang, Li-xia; Hu, Xiao-hui; Ren, Wen-qi; Zhang, Li; Ni, Xin-xin

    2016-02-01

    Two cultivars of tomato (Solanum lycopersicum, cvs. 'Jinpengchaoguan' and 'Zhongza No. 9', with the former being more tolerant to saline-alkaline stress) seedlings grown hydroponically were subjected to salinity-alkalinity stress condition (NaCl: Na2SO4:NaHCO3:Na2CO3 = 1:9:9:1) without or with foliar application of 0.25 mmol . L-1 spermidine (Spd), and the root morphology and physiological characteristics of mitochondrial membrane were analyzed 8 days after treatment, to explore the protective effects of exogenous Spd on mitochondrial function in tomato roots under salinity-alkalinity stress. The results showed that the salinity-alkalinity stress increased the concentrations of both mitochondrial H2O2 and MDA as well as the mitochondrial membrane permeability in the roots of the two cultivars, while it decreased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity, which impaired the mitochondria and therefore inhibited the root growth; and these effects were more obvious in 'Zhongza No. 9' than in 'Jinpengechaoguan'. Under the salinity-alkalinity stress, foliar application Spd could effectively decrease the concentrations of mitochondrial H2O2 and MDA and mitochondrial membrane permeability, while increased the mitochondrial membrane fluidity, membrane potential, Cyt c/a and H+-ATPase activity. These results suggested that exogenous Spd could effectively mitigate the damage on mitochondria induced by salinity-alkalinity stress, and the alleviation effect was more obvious in 'Zhongza No. 9' than in 'Jinpengchaoguan'. PMID:27396122

  13. The Influence of Work-Related Chronic Stress on the Regulation of Emotion and on Functional Connectivity in the Brain

    PubMed Central

    Golkar, Armita; Johansson, Emilia; Kasahara, Maki; Osika, Walter; Perski, Aleksander; Savic, Ivanka

    2014-01-01

    Despite mounting reports about the negative effects of chronic occupational stress on cognitive and emotional functions, the underlying mechanisms are unknown. Recent findings from structural MRI raise the question whether this condition could be associated with a functional uncoupling of the limbic networks and an impaired modulation of emotional stress. To address this, 40 subjects suffering from burnout symptoms attributed to chronic occupational stress and 70 controls were investigated using resting state functional MRI. The participants' ability to up- regulate, down-regulate, and maintain emotion was evaluated by recording their acoustic startle response while viewing neutral and negatively loaded images. Functional connectivity was calculated from amygdala seed regions, using explorative linear correlation analysis. Stressed subjects were less capable of down-regulating negative emotion, but had normal acoustic startle responses when asked to up-regulate or maintain emotion and when no regulation was required. The functional connectivity between the amygdala and the anterior cingulate cortex correlated with the ability to down-regulate negative emotion. This connectivity was significantly weaker in the burnout group, as was the amygdala connectivity with the dorsolateral prefrontal cortex and the motor cortex, whereas connectivity from the amygdala to the cerebellum and the insular cortex were stronger. In subjects suffering from chronic occupational stress, the functional couplings within the emotion- and stress-processing limbic networks seem to be altered, and associated with a reduced ability to down-regulate the response to emotional stress, providing a biological substrate for a further facilitation of the stress condition. PMID:25184294

  14. The influence of work-related chronic stress on the regulation of emotion and on functional connectivity in the brain.

    PubMed

    Golkar, Armita; Johansson, Emilia; Kasahara, Maki; Osika, Walter; Perski, Aleksander; Savic, Ivanka

    2014-01-01

    Despite mounting reports about the negative effects of chronic occupational stress on cognitive and emotional functions, the underlying mechanisms are unknown. Recent findings from structural MRI raise the question whether this condition could be associated with a functional uncoupling of the limbic networks and an impaired modulation of emotional stress. To address this, 40 subjects suffering from burnout symptoms attributed to chronic occupational stress and 70 controls were investigated using resting state functional MRI. The participants' ability to up- regulate, down-regulate, and maintain emotion was evaluated by recording their acoustic startle response while viewing neutral and negatively loaded images. Functional connectivity was calculated from amygdala seed regions, using explorative linear correlation analysis. Stressed subjects were less capable of down-regulating negative emotion, but had normal acoustic startle responses when asked to up-regulate or maintain emotion and when no regulation was required. The functional connectivity between the amygdala and the anterior cingulate cortex correlated with the ability to down-regulate negative emotion. This connectivity was significantly weaker in the burnout group, as was the amygdala connectivity with the dorsolateral prefrontal cortex and the motor cortex, whereas connectivity from the amygdala to the cerebellum and the insular cortex were stronger. In subjects suffering from chronic occupational stress, the functional couplings within the emotion- and stress-processing limbic networks seem to be altered, and associated with a reduced ability to down-regulate the response to emotional stress, providing a biological substrate for a further facilitation of the stress condition. PMID:25184294

  15. Universal Stress Protein Exhibits a Redox-Dependent Chaperone Function in Arabidopsis and Enhances Plant Tolerance to Heat Shock and Oxidative Stress

    PubMed Central

    Jung, Young Jun; Melencion, Sarah Mae Boyles; Lee, Eun Seon; Park, Joung Hun; Alinapon, Cresilda Vergara; Oh, Hun Taek; Yun, Dae-Jin; Chi, Yong Hun; Lee, Sang Yeol

    2015-01-01

    Although a wide range of physiological information on Universal Stress Proteins (USPs) is available from many organisms, their biochemical, and molecular functions remain unidentified. The biochemical function of AtUSP (At3g53990) from Arabidopsis thaliana was therefore investigated. Plants over-expressing AtUSP showed a strong resistance to heat shock and oxidative stress, compared with wild-type and Atusp knock-out plants, confirming the crucial role of AtUSP in stress tolerance. AtUSP was present in a variety of structures including monomers, dimers, trimers, and oligomeric complexes, and switched in response to external stresses from low molecular weight (LMW) species to high molecular weight (HMW) complexes. AtUSP exhibited a strong chaperone function under stress conditions in particular, and this activity was significantly increased by heat treatment. Chaperone activity of AtUSP was critically regulated by the redox status of cells and accompanied by structural changes to the protein. Over-expression of AtUSP conferred a strong tolerance to heat shock and oxidative stress upon Arabidopsis, primarily via its chaperone function. PMID:26734042

  16. Cognitive adaptations to stressful environments: When childhood adversity enhances adult executive function.

    PubMed

    Mittal, Chiraag; Griskevicius, Vladas; Simpson, Jeffry A; Sung, Sooyeon; Young, Ethan S

    2015-10-01

    Can growing up in a stressful childhood environment enhance certain cognitive functions? Drawing participants from higher-income and lower-income backgrounds, we tested how adults who grew up in harsh or unpredictable environments fared on 2 types of executive function tasks: inhibition and shifting. People who experienced unpredictable childhoods performed worse at inhibition (overriding dominant responses), but performed better at shifting (efficiently switching between different tasks). This finding is consistent with the notion that shifting, but not inhibition, is especially useful in unpredictable environments. Importantly, differences in executive function between people who experienced unpredictable versus predictable childhoods emerged only when they were tested in uncertain contexts. This catalyst suggests that some individual differences related to early life experience are manifested under conditions of uncertainty in adulthood. Viewed as a whole, these findings indicate that adverse childhood environments do not universally impair mental functioning, but can actually enhance specific types of cognitive performance in the face of uncertainty. PMID:26414842

  17. Functional recovery from sciatic nerve crush lesion in the rat correlates with individual differences in responses to chronic intermittent stress.

    PubMed

    van Meeteren, N L; Brakkee, J H; Helders, P J; Wiegant, V M; Gispen, W H

    1997-06-15

    The aim of the present study was to monitor the influence of chronic stress on functional recovery from a sciatic nerve crush lesion in the rat. Male Wistar rats underwent standard unilateral sciatic nerve crush. Subsequently, chronic stress was induced during the recovery phase using a daily 30 min shock box session where rats received three electric footshocks each session (0.5 sec, 1 mA). Reduced body weight gain, adrenal gland hypertrophy, and thymus involution indicated that the stress rats were chronically stressed. Evaluation of sensorimotor function revealed significant differences in recovery between control and stress groups. Correlational analysis of individual stress rats indicated that recovery of the walking pattern was negatively correlated with adrenal gland and medulla enlargement, thymus involution, and plasma levels of adrenocorticotrophic hormone (ACTH) and corticosterone 45 min following the final stress session. In control rats, the index of sciatic nerve function (SF index, expressed as the difference between the injured paw and the intact contralateral paw as a percentage) was significantly correlated with adrenal medulla weight only. The present study reveals that chronic intermittent footshock stress impedes sensorimotor recovery following a sciatic nerve crush lesion and that the consequences of chronic intermittent stress are individually determined. We suggest that the quality of functional locomotor recovery after nerve crush lesion is related to the adaptive capacity or coping style of the individual rat. PMID:9210522

  18. Advances in functional genomics for investigating salinity stress tolerance mechanisms in cereals.

    PubMed

    Shelden, Megan C; Roessner, Ute

    2013-01-01

    Abiotic stresses such as low water availability and high salinity are major causes of cereal crop yield losses and significantly impact on sustainability. Wheat and barley are two of the most important cereal crops (after maize and rice) and are grown in increasingly hostile environments with soil salinity and drought both expected to increase this century, reducing the availability of arable land. Barley and wheat are classified as glycophytes (salt-sensitive), yet they are more salt-tolerant than other cereal crops such as rice and so are good models for studying salt tolerance in cereals. The exploitation of genetic variation of phenotypic traits through plant breeding could significantly improve growth of cereals in salinity-affected regions, thus leading to improved crop yields. Genetic variation in phenotypic traits for abiotic stress tolerance have been identified in land races and wild germplasm but the molecular basis of these differences is often difficult to determine due to the complex genetic nature of these species. High-throughput functional genomics technologies, such as transcriptomics, metabolomics, proteomics, and ionomics are powerful tools for investigating the molecular responses of plants to abiotic stress. The advancement of these technologies has allowed for the identification and quantification of transcript/metabolites in specific cell types and/or tissues. Using these new technologies on plants will provide a powerful tool to uncovering genetic traits in more complex species such as wheat and barley and provide novel insights into the molecular mechanisms of salinity stress tolerance. PMID:23717314

  19. Wheat NF-YA10 functions independently in salinity and drought stress.

    PubMed

    Ma, Xiaoyan; Li, Chunlong; Wang, Mei

    2015-01-01

    The transcription factor NUCLEAR FACTOR Y (NF-Y) plays an essential role in many developmental and stress-responsive processes in plants. NF-Y composed of 3 subunits, NF-YA, NF-YB, and NF-YC, targets the CCAAT box, a common cis-element in eukaryotic promoters. We recently identified a gene TaNF-YA10-1 from the wheat salinity tolerant cultivar SR3 and found that recombinant TaNF-YA10-1 could successfully bind to the CCAAT motif in vitro. We also showed that the constitutive expression of TaNF-YA10-1 in Arabidopsis thaliana significantly increased the plant's sensitivity to salinity. Here, we further demonstrated that TaNF-YA10-1 -overexpressing plants conferred drought tolerance as judged from the relative root length and whole-plant growth under drought stress. These results suggest that TaNF-YA10-1 functions independently in salinity and drought stress. Our findings are helpful in understanding the distinct roles of NF-YA in plant stress responses. PMID:26083807

  20. Intranasal Dexmedetomidine on Stress Hormones, Inflammatory Markers, and Postoperative Analgesia after Functional Endoscopic Sinus Surgery

    PubMed Central

    Tang, Chaoliang; Huang, Xiang; Kang, Fang; Chai, Xiaoqing; Wang, Song; Yin, Guobing; Wang, Hongtao; Li, Juan

    2015-01-01

    Background. A strong ongoing intraoperative stress response can cause serious adverse reactions and affect the postoperative outcome. This study evaluated the effect of intranasally administered dexmedetomidine (DEX) in combination with local anesthesia (LA) on the relief of stress and the inflammatory response during functional endoscopic sinus surgery (FESS). Methods. Sixty patients undergoing FESS were randomly allocated to receive either intranasal DEX (DEX group) or intranasal saline (Placebo group) 1 h before surgery. Stress hormones, inflammatory markers, postoperative pain relief, hemodynamic variables, blood loss, surgical field quality, body movements, and satisfaction were assessed. Results. Plasma epinephrine, norepinephrine, and blood glucose levels were significantly lower in DEX group as were the plasma IL-6 and TNF-α levels (P < 0.05). The weighted areas under the curve (AUCw) of the VAS scores were also significantly lower in DEX group at 2–12 h after surgery (P < 0.001). Furthermore, hemodynamic variables, blood loss, body movements, discomfort with hemostatic stuffing, surgical field quality, and satisfaction scores of patients and surgeons were significantly better (P < 0.05) in DEX group. Conclusions. Patients receiving intranasal DEX with LA for FESS exhibited less perioperative stress and inflammatory response as well as better postoperative comfort with hemostatic stuffing and analgesia. PMID:26199465

  1. Disrupted resting-state insular subregions functional connectivity in post-traumatic stress disorder.

    PubMed

    Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Guo, Xiaonan; Chen, Huafu

    2016-07-01

    Post-traumatic stress disorder (PTSD) is suggested to be a structural and functional abnormality in the insula. The insula, which consists of distinct subregions with various patterns of connectivity, displays complex and diverse functions. However, whether these insular subregions have different patterns of connectivity in PTSD remains unclear. Investigating the abnormal functional connectivity of the insular subregions is crucial to reveal its potential effect on diseases specifically PTSD. This study uses a seed-based method to investigate the altered resting-state functional connectivity of insular subregions in PTSD. We found that patients with PTSD showed reduced functional connectivity compared with healthy controls (HCs) between the left ventral anterior insula and the anterior cingulate cortex. The patients with PTSD also exhibited decreased functional connectivity between the right posterior insula and left inferior parietal lobe, and the postcentral gyrus relative to HCs. These results suggest the involvement of altered functional connectivity of insular subregions in the abnormal regulation of emotion and processing of somatosensory information in patients with PTSD. Such impairments in functional connectivity patterns of the insular subregions may advance our understanding of the pathophysiological basis underlying PTSD. PMID:27399097

  2. ROS signaling, oxidative stress and Nrf2 in pancreatic beta-cell function

    SciTech Connect

    Pi Jingbo; Zhang Qiang; Fu Jingqi; Woods, Courtney G.; Hou Yongyong; Corkey, Barbara E.; Collins, Sheila; Andersen, Melvin E.

    2010-04-01

    This review focuses on the emerging evidence that reactive oxygen species (ROS) derived from glucose metabolism, such as H{sub 2}O{sub 2}, act as metabolic signaling molecules for glucose-stimulated insulin secretion (GSIS) in pancreatic beta-cells. Particular emphasis is placed on the potential inhibitory role of endogenous antioxidants, which rise in response to oxidative stress, in glucose-triggered ROS and GSIS. We propose that cellular adaptive response to oxidative stress challenge, such as nuclear factor E2-related factor 2 (Nrf2)-mediated antioxidant induction, plays paradoxical roles in pancreatic beta-cell function. On the one hand, induction of antioxidant enzymes protects beta-cells from oxidative damage and possible cell death, thus minimizing oxidative damage-related impairment of insulin secretion. On the other hand, the induction of antioxidant enzymes by Nrf2 activation blunts glucose-triggered ROS signaling, thus resulting in reduced GSIS. These two premises are potentially relevant to impairment of beta-cells occurring in the late and early stage of Type 2 diabetes, respectively. In addition, we summarized our recent findings that persistent oxidative stress due to absence of uncoupling protein 2 activates cellular adaptive response which is associated with impaired pancreatic beta-cell function.

  3. Effects of mechanical stresses on sperm function and fertilization rate in mice.

    PubMed

    Shi, Xiao; Wang, Ting; Qiu, Zhuo Lin; Li, Ke; Li, Liu; Chan, Carol Pui Shan; Chan, Si Mei; Li, Tian-Chiu; Quan, Song

    2016-01-01

    In this study, we investigated whether any of the observed changes in mouse sperm function tests secondary to mechanical stresses (centrifugation and pipetting) correlate with sperm fertilization ability. Chinese Kunming mice were used as sperm and oocyte donors. Sperm samples were allocated evenly into centrifugation, pipette, and control groups. Sperm plasma membrane integrity (PMI), mitochondrial membrane permeability (MMP), baseline and stimulated intracellular ROS, and sperm fertilization ability were measured by hypo-osmotic swelling, flow cytometry, and fertilization tests. Parallel studies were conducted and all tests were repeated six times. Our results showed that after centrifugation, the progressive motility, average path velocity, and overall sperm motility and PMI decreased significantly (p < 0.05). In addition, the MMP level decreased significantly in viable sperm when the centrifugation condition reached 1,400 g × 15 minutes (p < 0.05). When pipetting was performed two or more times, progressive motility, average path velocity, and overall sperm motility decreased significantly (p < 0.05); when it was performed four or more times, sperm membrane integrity and intracellular basal ROS level of viable sperm was also significantly decreased (p < 0.05). In conclusion, various mechanical stresses seem to affect sperm function, however this does not appear to alter fertilization rate. Laboratory handling steps should be minimized to avoid unnecessary mechanical stresses being applied to sperm samples. PMID:26889695

  4. Obesity-induced oxidative stress, accelerated functional decline with age and increased mortality in mice

    PubMed Central

    Zhang, Yiqiang; Fischer, Kathleen E.; Soto, Vanessa; Liu, Yuhong; Sosnowska, Danuta; Richardson, Arlan; Salmon, Adam B.

    2015-01-01

    Obesity is a serious chronic disease that increases the risk of numerous co-morbidities including metabolic syndrome, cardiovascular disease and cancer as well as increases risk of mortality leading some to suggest this represents accelerated aging. Obesity is associated with significant increases in oxidative stress in vivo and, despite the well-explored relationship between oxidative stress and aging, the role this plays in the increased mortality of obese subjects remains an unanswered question. Here, we addressed this by undertaking a comprehensive, longitudinal study of a group of high fat-fed obese mice and assessed both their changes in oxidative stress and in their performance in physiological assays known to decline with aging. In female C57BL/6J mice fed a high-fat diet starting in adulthood, mortality was significantly increased in high fat-fed mice as was oxidative damage in vivo. High fat-feeding significantly accelerated the decline in performance in several assays, including activity, gait, and rotarod. However, we also found that obesity had little effect on other markers and actually improved performance in grip strength, a marker of muscular function. Together, this first comprehensive assessment of longitudinal functional changes in high fat-fed mice suggests that obesity may induce segmental acceleration of some of the aging process. PMID:25558793

  5. Biomarkers of oxidative stress in erythrocytes as a function of human age.

    PubMed

    Maurya, Pawan Kumar; Kumar, Prabhanshu; Chandra, Pranjal

    2015-12-26

    Despite more than 300 theories to explain the aging process, oxidative stress theory offers the best mechanism to explain aging and age related disorders. Several studies has shown the importance of oxidative stress during aging. PubMed, Science Direct and Springer online data bases are taken into consideration to write this mini-review. Human erythrocytes are most abundant and specialized cells in the body. Erythrocytes were extensively studied due to their metabolism and gas transport functions. Recent studies on erythrocytes have provided us detailed information of cell membrane and its structural organization that may help in studying the aging and age associated changes. The susceptibility of an organism is associated with the antioxidant potential of the body. Erythrocytes have potent antioxidant protection consisting of enzymatic and non-enzymatic pathways that counteract with reactive oxygen species, thus maintaining the redox regulation in the body. The non-enzymatic and enzymatic antioxidants and other biomarkers associated with erythrocyte membrane transport functions are the main content of this review. Biomarkers of oxidative stress in erythrocytes and its membrane were taken into the consideration during human aging that will be the main subject of this mini- review. PMID:26713282

  6. Heat stress impairs mice granulosa cell function by diminishing steroids production and inducing apoptosis.

    PubMed

    Luo, Man; Li, Lian; Xiao, Cheng; Sun, Yu; Wang, Gen-Lin

    2016-01-01

    Ovarian injury can be induced by heat stress. Mice granulosa cells (GCs) are critical for normal ovarian function and they synthesize a variety of growth factors and steroids for the follicle. Furthermore, the growth, differentiation, and maturate of theca cells and oocyte are dependent upon the synthesis of GCs. Due to the critical biological functions of GCs, we hypothesized that the apoptosis and dysfunction of GCs could also be induced by heat stress. We analyzed GCs apoptosis and evaluated the expression of apoptosis-related genes (caspase-3, Bax, Bcl-2) after heat treatment. Radio immunity assay was used to measure the secretion of 17β-estradiol (E2) and progesterone (P4). RT-PCR was used to evaluate the expression of steroids-related genes (Star, CYP11A1, CYP19A1). Our data suggested that heat stress inhibited GCs proliferation, induced GCs apoptosis, decreased E2 and P4 secretion, reduced the steroids-related genes mRNA expression. Besides, our results indicated that heat treatment-induced apoptosis of GCs through the mitochondrial pathway, which involved caspase-3 and Bax. The reduction in steroids secretion and mRNA expression of Star, CYP11A1, and CYP19A1 might also play a role in heat-induced GCs apoptosis and ovarian injury. PMID:26602771

  7. Biomarkers of oxidative stress in erythrocytes as a function of human age

    PubMed Central

    Maurya, Pawan Kumar; Kumar, Prabhanshu; Chandra, Pranjal

    2015-01-01

    Despite more than 300 theories to explain the aging process, oxidative stress theory offers the best mechanism to explain aging and age related disorders. Several studies has shown the importance of oxidative stress during aging. PubMed, Science Direct and Springer online data bases are taken into consideration to write this mini-review. Human erythrocytes are most abundant and specialized cells in the body. Erythrocytes were extensively studied due to their metabolism and gas transport functions. Recent studies on erythrocytes have provided us detailed information of cell membrane and its structural organization that may help in studying the aging and age associated changes. The susceptibility of an organism is associated with the antioxidant potential of the body. Erythrocytes have potent antioxidant protection consisting of enzymatic and non-enzymatic pathways that counteract with reactive oxygen species, thus maintaining the redox regulation in the body. The non-enzymatic and enzymatic antioxidants and other biomarkers associated with erythrocyte membrane transport functions are the main content of this review. Biomarkers of oxidative stress in erythrocytes and its membrane were taken into the consideration during human aging that will be the main subject of this mini- review. PMID:26713282

  8. Relationship of social support to stress responses and immune function in healthy and asthmatic adolescents.

    PubMed

    Kang, D H; Coe, C L; Karaszewski, J; McCarthy, D O

    1998-04-01

    Although most clinicians believe that social support has beneficial effects on health, the mechanisms mediating this relationship have not been clearly established. We examined the direct effect of social support on several immune measures and its role in moderating the response to academic exams in healthy and asthmatic adolescents. Three types of students--healthy, mild asthma, and severe asthma--completed social support and stress questionnaires and gave blood samples during the midsemester and final exam periods. Social support and natural killer cell (NK) function showed a significant reduction during exams in both healthy and asthmatic adolescents. Social support, however, did not have a direct effect on immune responses. Nevertheless, high social support appeared to attenuate the magnitude of exam-induced reduction in NK activity, suggesting a role for social support in protecting against immune decrements during times of stress. PMID:9535404

  9. Stress-Related Cognitive Interference Predicts Cognitive Function in Old Age

    PubMed Central

    Stawski, Robert S.; Sliwinski, Martin J.; Smyth, Joshua M.; University, Syracuse

    2010-01-01

    Both subjective distress and cognitive interference have been proposed as mechanisms underlying the negative effects of stress on cognition. Studies of aging have shown that distress is associated with lower cognitive performance, but none have examined the effects of cognitive interference. One hundred eleven older adults (Mage = 80) completed measures of working memory, processing speed, and episodic memory as well as self-report measures of subjective distress and cognitive interference. Cognitive interference was strongly associated with poorer performance on all 3 cognitive constructs, whereas distress was only modestly associated with lower working memory. The results suggest that cognitive process related to stress is an important predictor of cognitive function in advanced age. PMID:16953715

  10. Acute exercise improves endothelial function despite increasing vascular resistance during stress in smokers and nonsmokers.

    PubMed

    Rooks, Cherie R; McCully, Kevin K; Dishman, Rod K

    2011-09-01

    The present study examined the effect of acute exercise on flow mediated dilation (FMD) and reactivity to neurovascular challenges among female smokers and nonsmokers. FMD was determined by arterial diameter, velocity, and blood flow measured by Doppler ultrasonography after forearm occlusion. Those measures and blood pressure and heart rate were also assessed in response to forehead cold and the Stroop Color-Word Conflict Test (CWT) before and after 30 min of rest or an acute bout of cycling exercise (∼50% VO₂ peak). Baseline FMD and stress responses were not different between smokers and nonsmokers. Compared to passive rest, exercise increased FMD and decreased arterial velocity and blood flow responses during the Stroop CWT and forehead cold in both groups. Overall, acute exercise improved endothelial function among smokers and nonsmokers despite increasing vascular resistance and reducing limb blood flow during neurovascular stress. PMID:21457274

  11. Functional analysis of stress protein data in a flor yeast subjected to a biofilm forming condition

    PubMed Central

    Moreno-García, Jaime; Mauricio, Juan Carlos; Moreno, Juan; García-Martínez, Teresa

    2016-01-01

    In this data article, an OFFGEL fractionator coupled to LTQ Orbitrap XL MS equipment and a SGD filtering were used to detect in a biofilm-forming flor yeast strain, the maximum possible number of stress proteins under the first stage of a biofilm formation conditions (BFC) and under an initial stage of fermentation used as reference, so-called non-biofilm formation condition (NBFC). Protein functional analysis – based on cellular components and biological process GO terms – was performed for these proteins through the SGD Gene Ontology Slim Mapper tool. A detailed analysis and interpretation of the data can be found in “Stress responsive proteins of a flor yeast strain during the early stages of biofilm formation” [1]. PMID:27104213

  12. Functional analysis of stress protein data in a flor yeast subjected to a biofilm forming condition.

    PubMed

    Moreno-García, Jaime; Mauricio, Juan Carlos; Moreno, Juan; García-Martínez, Teresa

    2016-06-01

    In this data article, an OFFGEL fractionator coupled to LTQ Orbitrap XL MS equipment and a SGD filtering were used to detect in a biofilm-forming flor yeast strain, the maximum possible number of stress proteins under the first stage of a biofilm formation conditions (BFC) and under an initial stage of fermentation used as reference, so-called non-biofilm formation condition (NBFC). Protein functional analysis - based on cellular components and biological process GO terms - was performed for these proteins through the SGD Gene Ontology Slim Mapper tool. A detailed analysis and interpretation of the data can be found in "Stress responsive proteins of a flor yeast strain during the early stages of biofilm formation" [1]. PMID:27104213

  13. Emerging Importance of Helicases in Plant Stress Tolerance: Characterization of Oryza sativa Repair Helicase XPB2 Promoter and Its Functional Validation in Tobacco under Multiple Stresses.

    PubMed

    Raikwar, Shailendra; Srivastava, Vineet K; Gill, Sarvajeet S; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. Helicases, the unique molecular motors, are emerged as prospective molecules to engineer stress tolerance in plants and are involved in nucleic acid metabolism including DNA repair. The repair helicase, XPB is an evolutionary conserved protein present in different organisms, including plants. Availability of few efficient promoters for gene expression in plants provoked us to study the promoter of XPB for better understanding of gene regulation under stress conditions. Here, we report the in silico analysis of novel stress inducible promoter of Oryza sativa XPB2 (OsXPB2). The in vivo validation of functionality/activity of OsXPB2 promoter under abiotic and hormonal stress conditions was performed by Agrobacterium-mediated transient assay in tobacco leaves using OsXPB2::GUS chimeric construct. The present research revealed that OsXPB2 promoter contains cis-elements accounting for various abiotic stresses (salt, dehydration, or cold) and hormone (Auxin, ABA, or MeJA) induced GUS expression/activity in the promoter-reporter assay. The promoter region of OsXPB2 contains CACG, GTAACG, CACGTG, CGTCA CCGCCGCGCT cis acting-elements which are reported to be salt, dehydration, cold, MeJA, or ABA responsive, respectively. Functional analysis was done by Agrobacterium-mediated transient assay using agroinfiltration in tobacco leaves, followed by GUS staining and fluorescence quantitative analyses. The results revealed high induction of GUS activity under multiple abiotic stresses as compared to mock treated control. The present findings suggest that OsXPB2 promoter is a multi-stress inducible promoter and has potential applications in sustainable crop production under abiotic stresses by regulating desirable pattern of gene expression. PMID:26734018

  14. Emerging Importance of Helicases in Plant Stress Tolerance: Characterization of Oryza sativa Repair Helicase XPB2 Promoter and Its Functional Validation in Tobacco under Multiple Stresses

    PubMed Central

    Raikwar, Shailendra; Srivastava, Vineet K.; Gill, Sarvajeet S.; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Genetic material always remains at the risk of spontaneous or induced damage which challenges the normal functioning of DNA molecule, thus, DNA repair is vital to protect the organisms against genetic damage. Helicases, the unique molecular motors, are emerged as prospective molecules to engineer stress tolerance in plants and are involved in nucleic acid metabolism including DNA repair. The repair helicase, XPB is an evolutionary conserved protein present in different organisms, including plants. Availability of few efficient promoters for gene expression in plants provoked us to study the promoter of XPB for better understanding of gene regulation under stress conditions. Here, we report the in silico analysis of novel stress inducible promoter of Oryza sativa XPB2 (OsXPB2). The in vivo validation of functionality/activity of OsXPB2 promoter under abiotic and hormonal stress conditions was performed by Agrobacterium-mediated transient assay in tobacco leaves using OsXPB2::GUS chimeric construct. The present research revealed that OsXPB2 promoter contains cis-elements accounting for various abiotic stresses (salt, dehydration, or cold) and hormone (Auxin, ABA, or MeJA) induced GUS expression/activity in the promoter-reporter assay. The promoter region of OsXPB2 contains CACG, GTAACG, CACGTG, CGTCA CCGCCGCGCT cis acting-elements which are reported to be salt, dehydration, cold, MeJA, or ABA responsive, respectively. Functional analysis was done by Agrobacterium-mediated transient assay using agroinfiltration in tobacco leaves, followed by GUS staining and fluorescence quantitative analyses. The results revealed high induction of GUS activity under multiple abiotic stresses as compared to mock treated control. The present findings suggest that OsXPB2 promoter is a multi-stress inducible promoter and has potential applications in sustainable crop production under abiotic stresses by regulating desirable pattern of gene expression. PMID:26734018

  15. An Indirect Effects Model of the Association between Poverty and Child Functioning: The Role of Children's Poverty-Related Stress

    ERIC Educational Resources Information Center

    Wadsworth, Martha E.; Raviv, Tali; Reinhard, Christine; Wolff, Brian; Santiago, Catherine DeCarlo; Einhorn, Lindsey

    2008-01-01

    The authors tested a theoretical model positing that poverty has an indirect effect on child and adolescent functioning through children's poverty-related stress. Path analyses with a multiethnic sample of 164 children aged 6 to 18 revealed that the stress associated with poverty, such as economic strain, family conflict, violence/trauma, and…

  16. Effect of dietary distillers dried grains with solubles on indicators of oxidative stress and immune function in growing pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function when fed to pigs. Therefore, indicators of oxidative stress and immune status were determine...

  17. The Relationship between Sources and Functions of Social Support and Dimensions of Child- and Parent-Related Stress

    ERIC Educational Resources Information Center

    Guralnick, M. J.; Hammond, M. A.; Neville, B.; Connor, R. T.

    2008-01-01

    Background: In this longitudinal study, we examined the relationship between the sources and functions of social support and dimensions of child- and parent-related stress for mothers of young children with mild developmental delays. Methods: Sixty-three mothers completed assessments of stress and support at two time points. Results: Multiple…

  18. The thin mirror deformation and stress distribution analysis based on different influence functions

    NASA Astrophysics Data System (ADS)

    Wang, Hongqiao; Fan, Bin; Wu, Yongqian; Liu, Haitao; Liu, Rong

    2014-08-01

    The active support technique can be applied in the fabrication of large thin meniscus mirror. It can reduce the grinding and polishing difficulty for thin mirror. Compare between two kinds of influence function, we correct the Zernike 5th, 6th, 10th and 11th mode deformation. The low-order Zernike modes which are prone to appearing during large primary mirror processing are revised with active support technology. Influence functions are expressed with Z coordinate value and Zernike coefficient of surface shape. This paper reports that respectively adopting different influence functions to solve correction forces and the correction forces compensates specific Zernike modes of mirror deformation. After comparing the PV and RMS values of amendatory residual of surface shape, we analyze the effect of different correction forces to the biggest stress on the underside of the primary mirror. We compare the two methods based on the PV and RMS values of the residual error and the Max-stress. Gain a conclusion that correction forces obtained from Z coordinate value of surface shape is superior to the one obtained from the Zernike coefficient of surface shape.

  19. Relief of Oxidative Stress Using Curcumin and Glutathione Functionalized ZnO Nanoparticles in HEK-293 Cell Line.

    PubMed

    Kumar, Amit; Zafaryab, Md; Umar, Ahmad; Rizvi, M M A; Fouad, H; Ansari, Z A; Ansari, S G

    2015-11-01

    To elucidate the effect of zinc oxide nanoparticles (ZnO-NPs) with different surface modifications in relieving the oxidative stress in cultured human embryonic kidney cells (HEK-293) following investigation was performed. Oxidative stress was artificially induced by hydrogen peroxide in HEK-293 cell culture and its management was studied. Alkyl amines modified ZnO-NPs with curcumin and reduced glutathione (GSH) functionalization was used in managing oxidative stress and had shown promising results. ZnO-NPs used in this study were synthesized via non-aqueous sol-gel method and FESEM characterisation showed them of spherical shape of about 20-50 nm size with amine, curcumin and GSH functionalization. UV-visible and FTIR spectroscopic characterizations confirmed functionalization of ZnO-NPs. Decrease in oxidative stress was found with the dose-dependent culture of HEK-293 cells with these functionalized ZnO-NPs. Cell viability and morphology, as observed using AFM and inverted microscope, was retained with the prescribed dosages of the functionalized nanoparticles while at higher dosages they caused cytotoxicity and death. Diethylamine (DEA) modified ZnO-NPs and their functionalization with GSH and curcumin were found more effective in managing oxidative stress in cells. Present study could help in designing economical and bio-compatible functionalized non-toxic nanoparticles designed for managing oxidative stress leading to possible therapeutical and medicinal uses. PMID:26554152

  20. Antihypertensive treatment with verapamil and amlodipine. Their effect on the functional autonomic and cardiovascular stress responses.

    PubMed

    Nazzaro, P; Manzari, M; Merlo, M; Triggiani, R; Scarano, A M; Lasciarrea, A; Pirrelli, A

    1995-09-01

    Many biological and psychological factors induce haemodynamic and extra-cardiovascular functional changes mediated by the autonomic nervous system. Pharmacological blood pressure reduction, as a neurovegetative stimulus, can change the arousal of the sympathetic nervous system. We evaluated the effects of two calcium channel blockers, verapamil and amlodipine, both administered as monotherapies, upon the sympathetic stress response in 23 randomized mild-to-moderate essential hypertensives (161 +/- 2/98 +/- 1 mmHg). Patients performed four stress tests (mental arithmetic, colour word Stroop, cold pressor and handgrip) while extracardiovascular and haemodynamic functions were assessed non-invasively at every heart beat, during baseline, stress and recovery phases. The sympathetic response was evaluated by computing the 'area-under-the-curve' (value x time) measured during the psychophysiological session. The session was repeated at run-in, after placebo and during treatment. After one month's treatment, baseline blood pressure was significantly reduced in patients treated with amlodipine (139 +/- 1/84 +/- 1 mmHg; P < 0.001) and verapamil (140 +/- 2/85 +/- 1 mmHg; P < 0.001). The emotional arousal (frontalis muscular contraction, skin conductance) was unchanged, but the cutaneous vascular response was reduced (P < 0.05) in patients treated with verapamil. No changes in systolic or diastolic blood pressure were detectable, but amlodipine increased the heart rate response (P < 0.05). In contrast, verapamil reduced the heart rate (P < 0.05) without depressing the cardiac output response, which was increased with amlodipine (P < 0.05). Total vascular resistance was significantly (P < 0.001) reduced with both the treatments. Consequently, functional cardiac load, expressed by pressure-rate product and cardiac power, was significantly enhanced with amlodipine and reduced with verapamil. In conclusion, the abnormal sympathetic stress response, which characterizes the

  1. Catecholamine responses to virtual combat: implications for post-traumatic stress and dimensions of functioning

    PubMed Central

    Highland, Krista B.; Costanzo, Michelle E.; Jovanovic, Tanja; Norrholm, Seth D.; Ndiongue, Rochelle B.; Reinhardt, Brian J.; Rothbaum, Barbara; Rizzo, Albert A.; Roy, Michael J.

    2015-01-01

    Posttraumatic stress disorder (PTSD) symptoms can result in functional impairment among service members (SMs), even in those without a clinical diagnosis. The variability in outcomes may be related to underlying catecholamine mechanisms. Individuals with PTSD tend to have elevated basal catecholamine levels, though less is known regarding catecholamine responses to trauma-related stimuli. We assessed whether catecholamine responses to a virtual combat environment impact the relationship between PTSD symptom clusters and elements of functioning. Eighty-seven clinically healthy SMs, within 2 months after deployment to Iraq or Afghanistan, completed self-report measures, viewed virtual-reality (VR) combat sequences, and had sequential blood draws. Norepinephrine responses to VR combat exposure moderated the relationship between avoidance symptoms and scales of functioning including physical functioning, physical-role functioning, and vitality. Among those with high levels of avoidance, norepinephrine change was inversely associated with functional status, whereas a positive correlation was observed for those with low levels of avoidance. Our findings represent a novel use of a virtual environment to display combat-related stimuli to returning SMs to elucidate mind-body connections inherent in their responses. The insight gained improves our understanding of post-deployment symptoms and quality of life in SMs and may facilitate enhancements in treatment. Further research is needed to validate these findings in other populations and to define the implications for treatment effectiveness. PMID:25852586

  2. Catecholamine responses to virtual combat: implications for post-traumatic stress and dimensions of functioning.

    PubMed

    Highland, Krista B; Costanzo, Michelle E; Jovanovic, Tanja; Norrholm, Seth D; Ndiongue, Rochelle B; Reinhardt, Brian J; Rothbaum, Barbara; Rizzo, Albert A; Roy, Michael J

    2015-01-01

    Posttraumatic stress disorder (PTSD) symptoms can result in functional impairment among service members (SMs), even in those without a clinical diagnosis. The variability in outcomes may be related to underlying catecholamine mechanisms. Individuals with PTSD tend to have elevated basal catecholamine levels, though less is known regarding catecholamine responses to trauma-related stimuli. We assessed whether catecholamine responses to a virtual combat environment impact the relationship between PTSD symptom clusters and elements of functioning. Eighty-seven clinically healthy SMs, within 2 months after deployment to Iraq or Afghanistan, completed self-report measures, viewed virtual-reality (VR) combat sequences, and had sequential blood draws. Norepinephrine responses to VR combat exposure moderated the relationship between avoidance symptoms and scales of functioning including physical functioning, physical-role functioning, and vitality. Among those with high levels of avoidance, norepinephrine change was inversely associated with functional status, whereas a positive correlation was observed for those with low levels of avoidance. Our findings represent a novel use of a virtual environment to display combat-related stimuli to returning SMs to elucidate mind-body connections inherent in their responses. The insight gained improves our understanding of post-deployment symptoms and quality of life in SMs and may facilitate enhancements in treatment. Further research is needed to validate these findings in other populations and to define the implications for treatment effectiveness. PMID:25852586

  3. Stress.

    PubMed

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself. PMID:18846841

  4. Energy harvesting from sea waves with consideration of airy and JONSWAP theory and optimization of energy harvester parameters

    NASA Astrophysics Data System (ADS)

    Mirab, Hadi; Fathi, Reza; Jahangiri, Vahid; Ettefagh, Mir Mohammad; Hassannejad, Reza

    2015-12-01

    One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.

  5. Effects of yogurt containing Lactobacillus plantarum HOKKAIDO on immune function and stress markers.

    PubMed

    Nishimura, Mie; Ohkawara, Tatsuya; Tetsuka, Kyohei; Kawasaki, Yo; Nakagawa, Ryoji; Satoh, Hiroki; Sato, Yuji; Nishihira, Jun

    2016-07-01

    Lactobacillus plantarum HOKKAIDO (HOKKAIDO strain) was isolated from well-pickled vegetables in Hokkaido, Japan. We report a randomized, double-blind, placebo-controlled study evaluating the effects of L. plantarum HOKKAIDO on immune function and stress markers in 171 adult subjects. Subjects were divided into three groups: the L. plantarum HOKKAIDO yogurt group, the placebo-1 group who ingested yogurt without the HOKKAIDO strain, and the placebo-2 group who ingested a yogurt-like dessert without the HOKKAIDO strain. Hematological tests and body composition measurements were performed before and after 4 and 8 weeks of blinded ingestion. Although no significant differences in natural killer cell activity were observed, it was found that neutrophil ratio significantly decreased and lymphocytes tended to increase in the HOKKAIDO strain yogurt group compared with the yogurt-like dessert group. In addition, the neutrophil-to-lymphocyte ratio, a stress marker, tended to improve in the HOKKAIDO strain yogurt group compared with the yogurt-like dessert group. These results suggest that the ingestion of HOKKAIDO strain yogurt tends to improve immune activity and decrease stress markers. PMID:27419093

  6. Heat-stress-induced metabolic changes and altered male reproductive function.

    PubMed

    Hou, Yuanlong; Wang, Xiaoyan; Lei, Zhihai; Ping, Jihui; Liu, Jiajian; Ma, Zhiyu; Zhang, Zheng; Jia, Cuicui; Jin, Mengmeng; Li, Xiang; Li, Xiaoliang; Chen, Shaoqiu; Lv, Yingfang; Gao, Yingdong; Jia, Wei; Su, Juan

    2015-03-01

    Heat stress can cause systemic physiological and biochemical alterations in living organisms. In reproductive systems, heat stress induces germ cell loss and poor quality semen. However, until now, little has been known about such a complex regulation process, particularly in the perspective of metabolism. In this study, serum, hypothalamus, and epididymis samples derived from male SD (Sprague-Dawley) rats being exposed to high environmental temperature (40 °C) 2 h per day for 7 consecutive days were analyzed using metabonomics strategies based on GC/TOFMS. Differentially expressed metabolites reveal that the energy metabolism, amino acid neurotransmitters, and monoamine neurotransmitters pathways are associated with heat stress, in accordance with changes of the three upstream neuroendocrine system pathways in the SNS (sympathetic adrenergic system), hypothalamic pituitary adrenal axis (HPA), and hypothalamic pituitary testis axis (HPT) axis. Many of these metabolites, especially in the epididymis, were found to be up-regulated, presumably due to a self-preserving action to resist the environmental hot irritation to maintain normal functioning of the male reproductive system. PMID:25607524

  7. Low dose dobutamine stress echocardiography predicts the improvement of left ventricular systolic function in dilated cardiomyopathy

    PubMed Central

    Kitaoka, H; Takata, J; Yabe, T; Hitomi, N; Furuno, T; Doi, Y

    1999-01-01

    OBJECTIVE—To determine whether dobutamine stress echocardiography can predict the improvement of left ventricular systolic function in patients with dilated cardiomyopathy (DCM).
METHODS—Myocardial contractile reserve, as assessed by dobutamine stress echocardiography, was determined in 18 patients with DCM (mean (SD) age 53 (13) years, left ventricular ejection fraction (LVEF) 28 (10)%) and compared with changes in LVEF during a follow up period of 15 (8) months. The LVEF and regional left ventricular wall motion score (0, normal to 4, dyskinesis) of 12 segments in short axis and four chamber views were analysed before and after dobutamine infusion (5-20 µg/kg/min).
RESULTS—During a follow up period of 15 (8) months, a significant improvement in LVEF (> 20%) was found in seven patients but not in the remaining 11. Baseline haemodynamic findings were similar in both groups. Patients with an improvement in follow up LVEF showed a greater change in wall motion score from baseline during dobutamine infusion than patients with no improvement (at rest, 1.7 (0.4) v 1.9 (0.2), NS; dobutamine 10 µg/kg/min, 0.6 (0.4) v 1.2 (0.4), p < 0.05). The percentage change in LVEF during dobutamine infusion was also significantly greater in patients who showed improvement than in those who did not. The change in LVEF during the follow up period (follow up LVEF/baseline LVEF) correlated well with the change in LVEF during dobutamine stress (LVEF at rest/LVEF at dobutamine 10 µg/kg/min; r = 0.74, p < 0.001).
CONCLUSIONS—Changes in left ventricular systolic performance during low dose dobutamine stress echocardiography are a useful marker to predict the outcome of left ventricular systolic function in patients with DCM.


Keywords: dilated cardiomyopathy; dobutamine stress echocardiography; contractile reserve PMID:10212172

  8. Exploring the relationship between exposure to technological and gastrointestinal stress and probiotic functional properties of lactobacilli and bifidobacteria.

    PubMed

    Amund, O D

    2016-09-01

    Strains of Lactobacillus and Bifidobacterium are considered probiotic because of their associated potential health benefits. Probiotics are commonly administered orally via incorporation into food products. Microorganisms for use as probiotics encounter stress conditions, which include acid, bile, osmotic, oxidative, heat and cold stresses. These can occur during processing and storage and during passage through the gastrointestinal tract, and can affect viability. Probiotic bacteria have to remain viable to confer any health benefits. Therefore, the ability to withstand technological and gastrointestinal stresses is crucial probiotic selection criteria. While the stress tolerance mechanisms of lactobacilli and bifidobacteria are largely understood, the impact of exposure to stressful conditions on the functional properties of surviving probiotic microorganisms is not clear. This review explores the potentially positive and negative relationships between exposure to stress conditions and probiotic functional properties, such as resistance to gastric acid and bile, adhesion and colonization potential, and tolerance to antibiotics. Protective strategies can be employed to combat negative effects of stress on functional properties. However, further research is needed to ascertain synergistic relationships between exposure to stress and probiotic properties. PMID:27461506

  9. Boldine protects endothelial function in hyperglycemia-induced oxidative stress through an antioxidant mechanism.

    PubMed

    Lau, Yeh Siang; Tian, Xiao Yu; Huang, Yu; Murugan, Dharmani; Achike, Francis I; Mustafa, Mohd Rais

    2013-02-01

    Increased oxidative stress is involved in the pathogenesis and progression of diabetes. Antioxidants are therapeutically beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1,10-dimethoxyaporphine) is a major alkaloid present in the leaves and bark of the boldo tree (Peumus boldus Molina), with known an antioxidant activity. This study examined the protective effects of boldine against high glucose-induced oxidative stress in rat aortic endothelial cells (RAEC) and its mechanisms of vasoprotection related to diabetic endothelial dysfunction. In RAEC exposed to high glucose (30 mM) for 48 h, pre-treatment with boldine reduced the elevated ROS and nitrotyrosine formation, and preserved nitric oxide (NO) production. Pre-incubation with β-NAPDH reduced the acetylcholine-induced endothelium-dependent relaxation; this attenuation was reversed by boldine. Compared with control, endothelium-dependent relaxation in the aortas of streptozotocin (STZ)-treated diabetic rats was significantly improved by both acute (1 μM, 30 min) and chronic (20mg/kg/daily, i.p., 7 days) treatment with boldine. Intracellular superoxide and peroxynitrite formation measured by DHE fluorescence or chemiluminescence assay were higher in sections of aortic rings from diabetic rats compared with control. Chronic boldine treatment normalized ROS over-production in the diabetic group and this correlated with reduction of NAD(P)H oxidase subunits, NOX2 and p47(phox). The present study shows that boldine reversed the increased ROS formation in high glucose-treated endothelial cells and restored endothelial function in STZ-induced diabetes by inhibiting oxidative stress and thus increasing NO bioavailability. PMID:23178655

  10. Stress-related function of bHLH109 in somatic embryo induction in Arabidopsis.

    PubMed

    Nowak, Katarzyna; Gaj, Małgorzata D

    2016-04-01

    The bHLH109 gene of the bHLH family was identified among the transcription factor encoding genes that were differentially expressed in an embryogenic culture of Arabidopsis. A strong activation of bHLH109 expression was found to be associated with somatic embryogenesis (SE) induction. Several pieces of evidence suggested the involvement of bHLH109 in SE, including the high stimulation of the gene expression in SE-induced explants, which contrasts to the drastically lower level of the gene transcripts in the non-embryogenic callus and in tissue that is induced towards shoot regeneration via organogenesis. Moreover, in contrast to the overexpression of bHLH109, which has been indicated to enhance SE induction in a culture, the bhlh109 knock-out mutation was found to impair the embryogenic potential of explants. In order to identify the genes interacting with the bHLH109, the candidate co-expressed genes were identified in a yeast one hybrid assay. The in vitro regulatory interactions that were identified were verified through mutant and expression analysis. The results suggest that in SE bHLH109 acts as an activator of ECP63, a member of the LEA (LATE EMBRYOGENESIS ABUNDANT) family. Among the potential regulators of bHLH109, three candidates (At5g61620, bZIP4 and bZIP43) were indicated to possibly control bHLH109. The functions of all of the genes that are assumed to interact with bHLH109 are annotated to stress responses. Collectively, the results of the study provide new evidence that cell responses to stress that is imposed under in vitro conditions underlies the promotion of SE. bHLH109 may play a central role in the stress-related mechanism of SE induction via an increased accumulation of the LEA protein (ECP63), which results in the enhanced tolerance of the cells to stress. PMID:26973252

  11. Absence of functional TolC protein causes increased stress response gene expression in Sinorhizobium meliloti

    PubMed Central

    2010-01-01

    Background The TolC protein from Sinorhizobium meliloti has previously been demonstrated to be required for establishing successful biological nitrogen fixation symbiosis with Medicago sativa. It is also needed in protein and exopolysaccharide secretion and for protection against osmotic and oxidative stresses. Here, the transcriptional profile of free-living S. meliloti 1021 tolC mutant is described as a step toward understanding its role in the physiology of the cell. Results Comparison of tolC mutant and wild-type strains transcriptomes showed 1177 genes with significantly increased expression while 325 had significantly decreased expression levels. The genes with an increased expression suggest the activation of a cytoplasmic and extracytoplasmic stress responses possibly mediated by the sigma factor RpoH1 and protein homologues of the CpxRA two-component regulatory system of Enterobacteria, respectively. Stress conditions are probably caused by perturbation of the cell envelope. Consistent with gene expression data, biochemical analysis indicates that the tolC mutant suffers from oxidative stress. This is illustrated by the elevated enzyme activity levels detected for catalase, superoxide dismutase and glutathione reductase. The observed increase in the expression of genes encoding products involved in central metabolism and transporters for nutrient uptake suggests a higher metabolic rate of the tolC mutant. We also demonstrated increased swarming motility in the tolC mutant strain. Absence of functional TolC caused decreased expression mainly of genes encoding products involved in nitrogen metabolism and transport. Conclusion This work shows how a mutation in the outer membrane protein TolC, common to many bacterial transport systems, affects expression of a large number of genes that act in concert to restore cell homeostasis. This finding further underlines the fundamental role of this protein in Sinorhizobium meliloti biology. PMID:20573193

  12. Analysis of corner cracks at hole by a 3-D weight function method with stresses from finite element method

    NASA Technical Reports Server (NTRS)

    Zhao, W.; Newman, J. C., Jr.; Sutton, M. A.; Wu, X. R.; Shivakumar, K. N.

    1995-01-01

    Stress intensity factors for quarter-elliptical corner cracks emanating from a circular hole are determined using a 3-D weight function method combined with a 3-D finite element method. The 3-D finite element method is used to analyze uncracked configuration and provide stress distribution in the region where crack is to occur. Using this stress distribution as input, the 3-D weight function method is used to determine stress intensity factors. Three different loading conditions, i.e. remote tension, remote bending and wedge loading, are considered for a wide range in geometrical parameters. The significance in using 3-D uncracked stress distribution and the difference between single and double corner cracks are studied. Typical crack opening displacements are also provided. Comparisons are made with solutions available in the literature.

  13. Stress and decision making: neural correlates of the interaction between stress, executive functions, and decision making under risk.

    PubMed

    Gathmann, Bettina; Schulte, Frank P; Maderwald, Stefan; Pawlikowski, Mirko; Starcke, Katrin; Schäfer, Lena C; Schöler, Tobias; Wolf, Oliver T; Brand, Matthias

    2014-03-01

    Stress and additional load on the executive system, produced by a parallel working memory task, impair decision making under risk. However, the combination of stress and a parallel task seems to preserve the decision-making performance [e.g., operationalized by the Game of Dice Task (GDT)] from decreasing, probably by a switch from serial to parallel processing. The question remains how the brain manages such demanding decision-making situations. The current study used a 7-tesla magnetic resonance imaging (MRI) system in order to investigate the underlying neural correlates of the interaction between stress (induced by the Trier Social Stress Test), risky decision making (GDT), and a parallel executive task (2-back task) to get a better understanding of those behavioral findings. The results show that on a behavioral level, stressed participants did not show significant differences in task performance. Interestingly, when comparing the stress group (SG) with the control group, the SG showed a greater increase in neural activation in the anterior prefrontal cortex when performing the 2-back task simultaneously with the GDT than when performing each task alone. This brain area is associated with parallel processing. Thus, the results may suggest that in stressful dual-tasking situations, where a decision has to be made when in parallel working memory is demanded, a stronger activation of a brain area associated with parallel processing takes place. The findings are in line with the idea that stress seems to trigger a switch from serial to parallel processing in demanding dual-tasking situations. PMID:24408441

  14. Correlation of melanophore index with a battery of functional genomic stress indicators for measurement of environmental stress in aquatic ecosystem.

    PubMed

    Daiwile, Atul P; Naoghare, Pravin K; Giripunje, Manisha D; Rao, P D Prasada; Ghosh, Tarun K; Krishnamurthi, Kannan; Alimba, Chibuisi G; Sivanesan, Saravanadevi

    2015-03-01

    The correlation of primary stress indicator; melanophore index (MI) with set of genomic stress indicators is important for a better understanding of the cellular stress pathway induced by xenobiotics in aquatic species. This study presents a correlation between melanophore index (MI) and genomic stress indicators in Oreochromis mossambicus treated with lead nitrate, phenol and hexachlorocyclohexane (HCH). O. mossambicus was exposed to sub-lethal concentrations of the different LC50 values (96 h) of the tested chemicals at varying exposure periods and the response via genomic stress indicators and scale melanophores were assessed in accordance with standard protocols. Melanophore index decreased significantly (p<0.01) in a time dependent pattern to the tested chemicals. Gene expression showed significant time dependent increase in the expression of heat shock proteins (HSP70 and HSP60). Vitellogenin (Vtg) expression insignificantly altered. Significant increase in the expression of melanin concentrating hormone (MCH) was observed in response to hexachlorocyclohexane (HCH) in the treated fish. The findings demonstrated an inverse relationship between melanophore index and the set of genomic stress indicators. PMID:25680093

  15. Functions of Nitric Oxide (NO) in Roots during Development and under Adverse Stress Conditions

    PubMed Central

    Corpas, Francisco J.; Barroso, Juan B.

    2015-01-01

    The free radical molecule, nitric oxide (NO), is present in the principal organs of plants, where it plays an important role in a wide range of physiological functions. Root growth and development are highly regulated by both internal and external factors such as nutrient availability, hormones, pattern formation, cell polarity and cell cycle control. The presence of NO in roots has opened up new areas of research on the role of NO, including root architecture, nutrient acquisition, microorganism interactions and the response mechanisms to adverse environmental conditions, among others. Additionally, the exogenous application of NO throughout the roots has the potential to counteract specific damages caused by certain stresses. This review aims to provide an up-to-date perspective on NO functions in the roots of higher plants. PMID:27135326

  16. Altered resting-state functional connectivity in post-traumatic stress disorder: a perfusion MRI study

    NASA Astrophysics Data System (ADS)

    Li, Baojuan; Liu, Jian; Liu, Yang; Lu, Hong-Bing; Yin, Hong

    2013-03-01

    The majority of studies on posttraumatic stress disorder (PTSD) so far have focused on delineating patterns of activations during cognitive processes. Recently, more and more researches have started to investigate functional connectivity in PTSD subjects using BOLD-fMRI. Functional connectivity analysis has been demonstrated as a powerful approach to identify biomarkers of different brain diseases. This study aimed to detect resting-state functional connectivity abnormities in patients with PTSD using arterial spin labeling (ASL) fMRI. As a completely non-invasive technique, ASL allows quantitative estimates of cerebral blood flow (CBF). Compared with BOLD-fMRI, ASL fMRI has many advantages, including less low-frequency signal drifts, superior functional localization, etc. In the current study, ASL images were collected from 10 survivors in mining disaster with recent onset PTSD and 10 survivors without PTSD. Decreased regional CBF in the right middle temporal gyrus, lingual gyrus, and postcentral gyrus was detected in the PTSD patients. Seed-based resting-state functional connectivity analysis was performed using an area in the right middle temporal gyrus as region of interest. Compared with the non-PTSD group, the PTSD subjects demonstrated increased functional connectivity between the right middle temporal gyrus and the right superior temporal gyrus, the left middle temporal gyrus. Meanwhile, decreased functional connectivity between the right middle temporal gyrus and the right postcentral gyrus, the right superior parietal lobule was also found in the PTSD patients. This is the first study which investigated resting-state functional connectivity in PTSD using ASL images. The results may provide new insight into the neural substrates of PTSD.

  17. Autophagy, Microbial Sensing, Endoplasmic Reticulum Stress, and Epithelial Function in Inflammatory Bowel Disease

    PubMed Central

    Kaser, Arthur; Blumberg, Richard S.

    2015-01-01

    Increasing evidence has emerged that supports an important intersection between 3 fundamental cell biologic pathways in the pathogenesis of inflammatory bowel disease. These include the intersection between autophagy, as revealed by the original identification of ATG16L1 and IRGM as major genetic risk factors for Crohn’s disease, and intracellular bacterial sensing, as shown by the importance of NOD2 in autophagy induction upon bacterial entry into the cell. A pathway closely linked to autophagy and innate immunity is the unfolded protein response, initiated by endoplasmic reticulum stress due to the accumulation of misfolded proteins, which is genetically related to ulcerative colitis and Crohn’s disease (XBP1 and ORMDL3). Hypomorphic ATG16L1, NOD2, and X box binding protein-1 possess the common attribute of profoundly affecting Paneth cells, specialized epithelial cells at the bottom of intestinal crypts involved in antimicrobial function. Together with their functional juxtaposition in the environmentally exposed intestinal epithelial cell, their remarkable functional convergence on Paneth cells and their behavior in response to environmental factors, including microbes, these 3 pathways are of increasing importance to understanding the pathogenesis of inflammatory bowel disease. Moreover, in conjunction with studies that model deficient nuclear factor-κB function, these studies suggest a central role for altered intestinal epithelial cell function as one of the earliest events in the development of inflammatory bowel disease. PMID:21530740

  18. Myocardial Function Improved by Electromagnetic Field Induction of Stress Protein hsp70

    PubMed Central

    George, Isaac; Geddis, Matthew S.; Lill, Zachary; Lin, Hana; Gomez, Teodoro; Blank, Martin; Oz, Mehmet C.; Goodman, Reba

    2011-01-01

    Studies on myocardial function have shown that hsp70, stimulated by an increase in temperature, leads to improved survival following ischemia reperfusion (I-R). Low frequency electromagnetic fields (EMF) also induce the stress protein hsp70, but without elevating temperature. We have examined the hemodynamic changes in concert with EMF preconditioning and the induction of hsp70 to determine whether improved myocardial function occurs following I-R injury in Sprague-Dawley rats. Animals were exposed to EMF (60Hz, 8µT) for 30 minutes prior to I-R. Ischemia was then induced by ligation of left anterior descending coronary artery (LAD) for 30 minutes, followed by 30 minutes of reperfusion. Blood and heart tissue levels for hsp70 taken at 10 minute intervals were determined by Western blot and RNA transcription by rtPCR. Significant upregulation of the HSP70 gene and increased hsp70 levels were measured in response to EMF pre-exposures. Invasive hemodynamics, as measured using a volume conductance catheter, demonstrated significant recovery of systolic contractile function after 30 minutes of reperfusion following EMF exposure. Additionally, isovolemic relaxation, a measure of ventricular diastolic function, was markedly improved in EMF-treated animals. In conclusion, noninvasive EMF induction of hsp70 preserved myocardial function and has the potential to improve tolerance to ischemic injury. PMID:18446816

  19. Stress ventricular function test in conscious, nonthoracotomised dogs to assess cardiac drug efficacy.

    PubMed

    French, W J; Averill, W; Ung, S; Laks, M M

    1985-01-01

    The measurement of left ventricular (LV) function is frequently performed in unconscious or thoracotomised animals in the resting state; these conditions may seriously affect the basal haemodynamic state. To assess myocardial function in conscious animals, a technique was developed to place a catheter across the atrial septum into the left ventricle without a thoracotomy. A stress ventricular function test (SVFT) was performed by raising the systemic blood pressure with methoxamine in the conscious dog. In order to demonstrate the effectiveness of the SVFT in the detection of a decrease in ventricular function, a SVFT was performed before and after the acute infusion of verapamil to determine resting and reserve LV function. A slope relating systolic aortic pressure to the LV end-diastolic pressure was obtained in 10 dogs using a low dose (0.005) and in four dogs a high dose (0.01 microgram X kg-1 X min-1) verapamil (V). The mean slope before V was 3.6 +/- 1.2 and after 2.0 +/- 0.92 (p less than 0.001). The day-to-day variability of the SVFT was less than 22% (coefficient of variability). The SVFT is a sensitive, reproducible method to assess resting and increased or decreased myocardial contractility and is useful in selecting appropriate doses of cardiac drugs to determine their effect on the myocardium during acute and chronic infusion studies in the conscious, nonthoracotomised dog. PMID:3986853

  20. Early weaning stress impairs development of mucosal barrier function in the porcine intestine

    PubMed Central

    Smith, Feli; Clark, Jessica E.; Overman, Beth L.; Tozel, Christena C.; Huang, Jennifer H.; Rivier, Jean E. F.; Blisklager, Anthony T.

    2010-01-01

    Early life stress is a predisposing factor for the development of chronic intestinal disorders in adult life. Here, we show that stress associated with early weaning in pigs leads to impaired mucosal barrier function. Early weaning (15- to 21-day weaning age) resulted in sustained impairment in intestinal barrier function, as indicated by reductions in jejunal transepithelial electrical resistance and elevations in mucosal-to-serosal flux of paracellular probes [3H]mannitol and [14C]inulin measured at 5 and 9 wk of age, compared with that shown in late-weaned pigs (23- to 28-day weaning age). Elevated baseline short-circuit current was observed in jejunum from early-weaned pigs and was shown to be mediated via enhanced Cl− secretion. Jejunal barrier dysfunction in early-weaned pigs coincided with increased lamina propria immune cell density particularly mucosal mast cells. The mast cell stabilizer drug sodium cromoglycolate ameliorated barrier dysfunction and hypersecretion in early-weaned pigs, demonstrating an important role of mast cells. Furthermore, activation of mast cells ex vivo with c48/80 and corticotrophin-releasing factor (CRF) in pig jejunum mounted in Ussing chambers induced barrier dysfunction and elevations in short-circuit current that were inhibited with mast cell protease inhibitors. Experiments in which selective CRF receptor antagonists were administered to early-weaned pigs revealed that CRF receptor 1 (CRFr1) activation mediates barrier dysfunction and hypersecretion, whereas CRFr2 activation may be responsible for novel protective properties in the porcine intestine in response to early life stress. PMID:19926814

  1. Multi-stressor impacts on fungal diversity and ecosystem functions in streams: natural vs. anthropogenic stress.

    PubMed

    Tolkkinen, M; Mykrä, H; Annala, M; Markkola, A M; Vuori, K M; Muotka, T

    2015-03-01

    Biological assemblages are often subjected to multiple stressors emerging from both anthropogenic activities and naturally stressful conditions, and species' responses to simultaneous stressors may differ from those predicted based on the individual effects of each stressor alone. We studied the influence of land-use disturbance (forest drainage) on fungal decomposer assemblages and leaf decomposition rates in naturally harsh (low pH caused by black-shale dominated geology) vs. circumneutral streams. We used pyrosequencing to determine fungal richness and assemblage structure. Decomposition rates did not differ between circumneutral and naturally acidic reference sites. However, the effect of forest drainage on microbial decomposition was more pronounced in the naturally acidic streams than in circumneutral streams. Single-effect responses of fungal assemblages were mainly related to geology. Community similarity was significantly higher in the naturally acidic disturbed sites than in corresponding reference sites, suggesting that land-use disturbance simplifies fungal assemblages in naturally stressful conditions. Naturally acidic streams supported distinct fungal assemblages with many OTUs (operational taxonomic unit) unique to these streams. Our results indicate that fungal assemblages in streams are sensitive to both structural and functional impairment in response to multiple stressors. Anthropogenic degradation of naturally acidic streams may decrease regional fungal diversity and impair ecosystem functions, and these globally occurring environments therefore deserve special attention in conservation planning. PMID:26236864

  2. Evaluation of effective-stress-function algorithm for nuclear fuel simulation

    SciTech Connect

    Kim, H. C.; Yang, Y. S.; Koo, Y. H.

    2013-07-01

    In a pressurized water reactor (PWR), the mechanical integrity of nuclear fuel is the most critical issue as it is an important barrier for fission products released into the environment. The integrity of zirconium cladding that surrounds uranium oxide can be threatened during off-normal operation owing to a pellet-cladding mechanical interaction (PCMI). To analyze the fuel and cladding behavior during off-operation, the fuel performance code should calculate an inelastic analysis in two - or three-dimensional calculations. In this paper, the effective stress function (ESF) algorithm based on a two-dimensional FE module has been implemented to simulate the inelastic behavior of the cladding with stability and accuracy. The ESF algorithm solves the governing equations of the inelastic constitutive behavior by calculating the zero of the appropriate effective-stress-function. To verify the accuracy of the ESF algorithm for an inelastic analysis, a code-to-code benchmark was performed using the commercial FE code, ANSYS 13.0. To demonstrate the stability and convergence of the implemented algorithm, the number of iterations in the ESF algorithm was compared with that in a sequential algorithm in the case of an inelastic problem. Consequently, the evaluation results demonstrate that the implemented ESF algorithm improves the efficiency of the computation without a loss of accuracy for an inelastic analysis. (authors)

  3. Epigenetics, Stress, and Their Potential Impact on Brain Network Function: A Focus on the Schizophrenia Diatheses

    PubMed Central

    Diwadkar, Vaibhav A.; Bustamante, Angela; Rai, Harinder; Uddin, Monica

    2014-01-01

    The recent sociodevelopmental cognitive model of schizophrenia/psychosis is a highly influential and compelling compendium of research findings. Here, we present logical extensions to this model incorporating ideas drawn from epigenetic mediation of psychiatric disease, and the plausible effects of epigenetics on the emergence of brain network function and dysfunction in adolescence. We discuss how gene–environment interactions, effected by epigenetic mechanisms, might in particular mediate the stress response (itself heavily implicated in the emergence of schizophrenia). Next, we discuss the plausible relevance of this framework for adolescent genetic risk populations, a risk group characterized by vexing and difficult-to-explain heterogeneity. We then discuss how exploring relationships between epigenetics and brain network dysfunction (a strongly validated finding in risk populations) can enhance understanding of the relationship between stress, epigenetics, and functional neurobiology, and the relevance of this relationship for the eventual emergence of schizophrenia/psychosis. We suggest that these considerations can expand the impact of models such as the sociodevelopmental cognitive model, increasing their explanatory reach. Ultimately, integration of these lines of research may enhance efforts of early identification, intervention, and treatment in adolescents at-risk for schizophrenia. PMID:25002852

  4. Heightened Functional Neural Activation to Psychological Stress Covaries With Exaggerated Blood Pressure Reactivity

    PubMed Central

    Gianaros, Peter J.; Jennings, J. Richard; Sheu, Lei K.; Derbyshire, Stuart W.G.; Matthews, Karen A.

    2016-01-01

    Individuals who show exaggerated blood pressure reactions to psychological stressors are at increased risk for hypertension, atherosclerosis, and stroke. We tested whether individuals who show exaggerated stressor-induced blood pressure reactivity also show heightened stressor-induced neural activation in brain areas involved in controlling the cardiovascular system. In a functional MRI study, 46 postmenopausal women (mean age: 68.04; SD: 1.35 years) performed a standardized Stroop color-word interference task that served as a stressor to increase blood pressure. Across individuals, a larger task-induced rise in blood pressure covaried with heightened and correlated patterns of activation in brain areas implicated previously in stress-related cardiovascular control: the perigenual and posterior cingulate cortex, bilateral prefrontal cortex, anterior insula, and cerebellum. Entered as a set in hierarchical regression analyses, activation values in these brain areas uniquely predicted the magnitude of task-induced changes in systolic (ΔR2=0.54; P<0.001) and diastolic (ΔR2=0.27; P<0.05) blood pressure after statistical control for task accuracy and subjective reports of task stress. Heightened stressor-induced activation of cingulate, prefrontal, insular, and cerebellar brain areas may represent a functional neural phenotype that characterizes individuals who are prone to show exaggerated cardiovascular reactivity. PMID:17101844

  5. Glucocorticoid mechanisms of functional connectivity changes in stress-related neuropsychiatric disorders

    PubMed Central

    Hall, Baila S.; Moda, Rachel N.; Liston, Conor

    2014-01-01

    Stress—especially chronic, uncontrollable stress—is an important risk factor for many neuropsychiatric disorders. The underlying mechanisms are complex and multifactorial, but they involve correlated changes in structural and functional measures of neuronal connectivity within cortical microcircuits and across neuroanatomically distributed brain networks. Here, we review evidence from animal models and human neuroimaging studies implicating stress-associated changes in functional connectivity in the pathogenesis of PTSD, depression, and other neuropsychiatric conditions. Changes in fMRI measures of corticocortical connectivity across distributed networks may be caused by specific structural alterations that have been observed in the prefrontal cortex, hippocampus, and other vulnerable brain regions. These effects are mediated in part by glucocorticoids, which are released from the adrenal gland in response to a stressor and also oscillate in synchrony with diurnal rhythms. Recent work indicates that circadian glucocorticoid oscillations act to balance synapse formation and pruning after learning and during development, and chronic stress disrupts this balance. We conclude by considering how disrupted glucocorticoid oscillations may contribute to the pathophysiology of depression and PTSD in vulnerable individuals, and how circadian rhythm disturbances may affect non-psychiatric populations, including frequent travelers, shift workers, and patients undergoing treatment for autoimmune disorders. PMID:25729760

  6. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function

    PubMed Central

    Charvat, Robert A.; Arrizabalaga, Gustavo

    2016-01-01

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites. PMID:26976749

  7. Effects of Exercise Intensity on Postexercise Endothelial Function and Oxidative Stress

    PubMed Central

    McClean, Conor; Harris, Ryan A.; Brown, Malcolm; Brown, John C.; Davison, Gareth W.

    2015-01-01

    Purpose. To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities. Methods. Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V˙O2max (mild); 20 minutes at 75% V˙O2max (moderate); or 5 minutes at 100% V˙O2max (maximal) in random order. Brachial artery flow-mediated dilation (FMD) was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1), lipid hydroperoxides (LOOHs), and lipid soluble antioxidants. Results. LOOH increased immediately following moderate exercise (P < 0.05). ET-1 was higher immediately after exercise and 3 hours after exercise in the mild trial compared to maximal one (P < 0.05). Transient decreases were detected for ΔFMD/ShearAUC from baseline following maximal exercise, but it normalised at 3 hours after exercise (P < 0.05). Shear rate was higher immediately after exercise in the maximal trial compared to mild exercise (P < 0.05). No changes in baseline diameter, peak diameter, absolute change in diameter, or FMD were observed following any of the exercise trials (P > 0.05). Conclusions. Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD. PMID:26583061

  8. Functional characterization of novel genotypes and cellular oxidative stress studies in propionic acidemia.

    PubMed

    Gallego-Villar, Lorena; Pérez-Cerdá, Celia; Pérez, Belén; Abia, David; Ugarte, Magdalena; Richard, Eva; Desviat, Lourdes R

    2013-09-01

    Propionic acidemia (PA), caused by a deficiency of the mitochondrial biotin dependent enzyme propionyl-CoA carboxylase (PCC) is one of the most frequent organic acidurias in humans. PA is caused by mutations in either the PCCA or PCCB genes encoding the α- and β-subunits of the PCC enzyme which are assembled as an α6β6 dodecamer. In this study we have investigated the molecular basis of the defect in ten fibroblast samples from PA patients. Using homology modeling with the recently solved crystal structure of the PCC holoenzyme and a eukaryotic expression system we have analyzed the structural and functional effect of novel point mutations, also revealing a novel splice defect by minigene analysis. In addition, we have investigated the contribution of oxidative stress to cellular damage measuring reactive oxygen species (ROS) levels and apoptosis parameters in patient fibroblasts, as recent studies point to a secondary mitochondrial dysfunction as pathophysiological mechanism in this disorder. The results show an increase in intracellular ROS content compared to controls, correlating with the activation of the JNK and p38 signaling pathways. Highest ROS levels were present in cells harboring functionally null mutations, including one severe missense mutation. This work provides molecular insight into the pathogenicity of PA variants and indicates that oxidative stress may be a major contributing factor to the cellular damage, supporting the proposal of antioxidant strategies as novel supplementary therapy in this rare disease. PMID:23053474

  9. Impairment of visual function and retinal ER stress activation in Wfs1-deficient mice.

    PubMed

    Bonnet Wersinger, Delphine; Benkafadar, Nesrine; Jagodzinska, Jolanta; Hamel, Christian; Tanizawa, Yukio; Lenaers, Guy; Delettre, Cécile

    2014-01-01

    Wolfram syndrome is an early onset genetic disease (1/180,000) featuring diabetes mellitus and optic neuropathy, associated to mutations in the WFS1 gene. Wfs1-/- mouse model shows pancreatic beta cell atrophy, but its visual performance has not been investigated, prompting us to study its visual function and histopathology of the retina and optic nerve. Electroretinogram and visual evoked potentials (VEPs) were performed in Wfs1-/- and Wfs1+/+ mice at 3, 6, 9 and 12 months of age. Fundi were pictured with Micron III apparatus. Retinal ganglion cell (RGC) abundance was determined from Brn3a immunolabeling of retinal sections. RGC axonal loss was quantified by electron microscopy in transversal optic nerve sections. Endoplasmic reticulum stress was assessed using immunoglobulin binding protein (BiP), protein disulfide isomerase (PDI) and inositol-requiring enzyme 1 alpha (Ire1α) markers. Electroretinograms amplitudes were slightly reduced and latencies increased with time in Wfs1-/- mice. Similarly, VEPs showed decreased N+P amplitudes and increased N-wave latency. Analysis of unfolded protein response signaling revealed an activation of endoplasmic reticulum stress in Wfs1-/- mutant mouse retinas. Altogether, progressive VEPs alterations with minimal neuronal cell loss suggest functional alteration of the action potential in the Wfs1-/- optic pathways. PMID:24823368

  10. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function.

    PubMed

    Charvat, Robert A; Arrizabalaga, Gustavo

    2016-01-01

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites. PMID:26976749

  11. Stress inversion of heterogeneous fault-slip data with unknown slip sense: An objective function algorithm contouring method

    NASA Astrophysics Data System (ADS)

    Hansen, John-Are; Bergh, Steffen G.; Osmundsen, Per Terje; Redfield, Tim F.

    2015-01-01

    We propose a new method for stress inversion and separation of principal stress states from heterogeneous fault-slip data. The method is semi-automatic, and is based on the moment method of stress inversion (Fry 1999) in combination with the objective function algorithm (OFA) for stress separation (Shan et al 2003). In the presented routine we randomly partition the heterogeneous fault-slip dataset into subsets ranging between one and six. The number of subsets K represents the number of possible mixed stress states in the fault-slip dataset. For each partition number K, we run the OFA 1000 times. Following this we plot and contour the principal stress axes, corresponding to the minimum value of the objective function for each run, in a stereonet. By evaluating how solution clusters of principal stress axes change with increasing number of subsets K, we are able to determine the number of mixed stress states and their optimal solutions for heterogeneous fault-slip datasets. While the numbers of subsets are underestimated, solution-clusters of principal stress axes represent average stress states. However, once the correct number of subsets is reached, solution clusters align with the slip-generating principal stress axes. The solution clusters then become stable, and overestimating the number of subsets does not significantly alter their orientation. The partition number K when stability is obtained thus determines the number of mixed stress states in the heterogeneous dataset, while the corresponding highest density solution clusters give the best estimate of the slip-generating principal stress axes and corresponding stress shape ratios. The inversion routine is tested and confirmed using synthetic data and fault-slip data from the Gullkista fault in Northern Norway. Because the stress calculation is based on the moment method, the inversion routine is insensitive to the correct assessment of slip sense, and only requires the slip vector and orientation of the

  12. Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: functional imaging in freely behaving rodent pups

    PubMed Central

    Bock, Jörg; Riedel, Anett; Braun, Katharina

    2012-01-01

    The trumpet-tailed rat or degu (Octodon degus) is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behavior. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method) in 8-day-old male degu pups the following stress conditions were compared: (A) pups together with parents and siblings (control), (B) separation of the litter from the parents, (C) individual separation from parents and siblings, and (D) individual separation and presentation of maternal calls. Condition (B) significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens (NAcc), and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C), where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D) maternal vocalizations “reactivated” brain activity in the cingulate and precentral medial cortex, NAcc, and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex (IL) and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other

  13. Heme Oxygenase-1 Induction Improves Cardiac Function following Myocardial Ischemia by Reducing Oxidative Stress

    PubMed Central

    Issan, Yossi; Kornowski, Ran; Aravot, Dan; Shainberg, Asher; Laniado-Schwartzman, Michal; Sodhi, Komal; Abraham, Nader G.; Hochhauser, Edith

    2014-01-01

    Background Oxidative stress plays a key role in exacerbating diabetes and cardiovascular disease. Heme oxygenase-1 (HO-1), a stress response protein, is cytoprotective, but its role in post myocardial infarction (MI) and diabetes is not fully characterized. We aimed to investigate the protection and the mechanisms of HO-1 induction in cardiomyocytes subjected to hypoxia and in diabetic mice subjected to LAD ligation. Methods In vitro: cultured cardiomyocytes were treated with cobalt-protoporphyrin (CoPP) and tin protoporphyrin (SnPP) prior to hypoxic stress. In vivo: CoPP treated streptozotocin-induced diabetic mice were subjected to LAD ligation for 2/24 h. Cardiac function, histology, biochemical damage markers and signaling pathways were measured. Results HO-1 induction lowered release of lactate dehydrogenase (LDH) and creatine phospho kinase (CK), decreased propidium iodide staining, improved cell morphology and preserved mitochondrial membrane potential in cardiomyocytes. In diabetic mice, Fractional Shortening (FS) was lower than non-diabetic mice (35±1%vs.41±2, respectively p<0.05). CoPP-treated diabetic animals improved cardiac function (43±2% p<0.01), reduced CK, Troponin T levels and infarct size compared to non-treated diabetic mice (P<0.01, P<0.001, P<0.01 respectively). CoPP-enhanced HO-1 protein levels and reduced oxidative stress in diabetic animals, as indicated by the decrease in superoxide levels in cardiac tissues and plasma TNFα levels (p<0.05). The increased levels of HO-1 by CoPP treatment after LAD ligation led to a shift of the Bcl-2/bax ratio towards the antiapoptotic process (p<0.05). CoPP significantly increased the expression levels of pAKT and pGSK3β (p<0.05) in cardiomyocytes and in diabetic mice with MI. SnPP abolished CoPP's cardioprotective effects. Conclusions HO-1 induction plays a role in cardioprotection against hypoxic damage in cardiomyocytes and in reducing post ischemic cardiac damage in the diabetic heart as proved by

  14. Memory CD8(+) T Cells Require Increased Concentrations of Acetate Induced by Stress for Optimal Function.

    PubMed

    Balmer, Maria L; Ma, Eric H; Bantug, Glenn R; Grählert, Jasmin; Pfister, Simona; Glatter, Timo; Jauch, Annaïse; Dimeloe, Sarah; Slack, Emma; Dehio, Philippe; Krzyzaniak, Magdalena A; King, Carolyn G; Burgener, Anne-Valérie; Fischer, Marco; Develioglu, Leyla; Belle, Réka; Recher, Mike; Bonilla, Weldy V; Macpherson, Andrew J; Hapfelmeier, Siegfried; Jones, Russell G; Hess, Christoph

    2016-06-21

    How systemic metabolic alterations during acute infections impact immune cell function remains poorly understood. We found that acetate accumulates in the serum within hours of systemic bacterial infections and that these increased acetate concentrations are required for optimal memory CD8(+) T cell function in vitro and in vivo. Mechanistically, upon uptake by memory CD8(+) T cells, stress levels of acetate expanded the cellular acetyl-coenzyme A pool via ATP citrate lyase and promoted acetylation of the enzyme GAPDH. This context-dependent post-translational modification enhanced GAPDH activity, catalyzing glycolysis and thus boosting rapid memory CD8(+) T cell responses. Accordingly, in a murine Listeria monocytogenes model, transfer of acetate-augmented memory CD8(+) T cells exerted superior immune control compared to control cells. Our results demonstrate that increased systemic acetate concentrations are functionally integrated by CD8(+) T cells and translate into increased glycolytic and functional capacity. The immune system thus directly relates systemic metabolism with immune alertness. PMID:27212436

  15. Expansion and Function of Repeat Domain Proteins During Stress and Development in Plants.

    PubMed

    Sharma, Manisha; Pandey, Girdhar K

    2015-01-01

    The recurrent repeats having conserved stretches of amino acids exists across all domains of life. Subsequent repetition of single sequence motif and the number and length of the minimal repeating motifs are essential characteristics innate to these proteins. The proteins with tandem peptide repeats are essential for providing surface to mediate protein-protein interactions for fundamental biological functions. Plants are enriched in tandem repeat containing proteins typically distributed into various families. This has been assumed that the occurrence of multigene repeats families in plants enable them to cope up with adverse environmental conditions and allow them to rapidly acclimatize to these conditions. The evolution, structure, and function of repeat proteins have been studied in all kingdoms of life. The presence of repeat proteins is particularly profuse in multicellular organisms in comparison to prokaryotes. The precipitous expansion of repeat proteins in plants is presumed to be through internal tandem duplications. Several repeat protein gene families have been identified in plants. Such as Armadillo (ARM), Ankyrin (ANK), HEAT, Kelch-like repeats, Tetratricopeptide (TPR), Leucine rich repeats (LRR), WD40, and Pentatricopeptide repeats (PPR). The structure and functions of these repeat proteins have been extensively studied in plants suggesting a critical role of these repeating peptides in plant cell physiology, stress and development. In this review, we illustrate the structural, functional, and evolutionary prospects of prolific repeat proteins in plants. PMID:26793205

  16. Female sexual function following mid-urethral slings for the treatment of stress urinary incontinence.

    PubMed

    Alwaal, A; Tian, X; Huang, Y; Zhao, L; Ma, L; Lin, G; Deng, D

    2016-07-01

    The aim of our study was to describe the impact of mid-urethral sling procedure for the treatment of stress urinary incontinence (SUI) on female sexual function. We used PubMed (updated March 2015) to conduct a literature electronic search that included peer-reviewed English language articles. We analyzed the studies about the impact of mid-urethral slings on female sexual function. There are different and contradictory results of the effects of mid-urethral sling on female sexual function. However, more papers show that women undergoing mid-urethral sling procedures report that their sexual function is improved or remains unchanged. The main mechanism of this improved sexuality is the complete relief from coital incontinence, reduction in anxiety and avoidance of sex, whereas the most common symptom related to worsened sexual activity is dyspareunia. Women undergoing sling procedures for SUI should be informed that their sexual activity is likely to remain unchanged or even improve after the operation, but that dyspareunia may occur. PMID:27146350

  17. Mitochondrial proteolytic stress induced by loss of mortalin function is rescued by Parkin and PINK1

    PubMed Central

    Burbulla, L F; Fitzgerald, J C; Stegen, K; Westermeier, J; Thost, A-K; Kato, H; Mokranjac, D; Sauerwald, J; Martins, L M; Woitalla, D; Rapaport, D; Riess, O; Proikas-Cezanne, T; Rasse, T M; Krüger, R

    2014-01-01

    The mitochondrial chaperone mortalin was implicated in Parkinson's disease (PD) because of its reduced levels in the brains of PD patients and disease-associated rare genetic variants that failed to rescue impaired mitochondrial integrity in cellular knockdown models. To uncover the molecular mechanisms underlying mortalin-related neurodegeneration, we dissected the cellular surveillance mechanisms related to mitochondrial quality control, defined the effects of reduced mortalin function at the molecular and cellular levels and investigated the functional interaction of mortalin with Parkin and PINK1, two PD-related proteins involved in mitochondrial homeostasis. We found that reduced mortalin function leads to: (1) activation of the mitochondrial unfolded protein response (UPR(mt)), (2) increased susceptibility towards intramitochondrial proteolytic stress, (3) increased autophagic degradation of fragmented mitochondria and (4) reduced mitochondrial mass in human cells in vitro and ex vivo. These alterations caused increased vulnerability toward apoptotic cell death. Proteotoxic perturbations induced by either partial loss of mortalin or chemical induction were rescued by complementation with native mortalin, but not disease-associated mortalin variants, and were independent of the integrity of autophagic pathways. However, Parkin and PINK1 rescued loss of mortalin phenotypes via increased lysosomal-mediated mitochondrial clearance and required intact autophagic machinery. Our results on loss of mortalin function reveal a direct link between impaired mitochondrial proteostasis, UPR(mt) and PD and show that effective removal of dysfunctional mitochondria via either genetic (PINK1 and Parkin overexpression) or pharmacological intervention (rapamycin) may compensate mitochondrial phenotypes. PMID:24743735

  18. Expansion and Function of Repeat Domain Proteins During Stress and Development in Plants

    PubMed Central

    Sharma, Manisha; Pandey, Girdhar K.

    2016-01-01

    The recurrent repeats having conserved stretches of amino acids exists across all domains of life. Subsequent repetition of single sequence motif and the number and length of the minimal repeating motifs are essential characteristics innate to these proteins. The proteins with tandem peptide repeats are essential for providing surface to mediate protein–protein interactions for fundamental biological functions. Plants are enriched in tandem repeat containing proteins typically distributed into various families. This has been assumed that the occurrence of multigene repeats families in plants enable them to cope up with adverse environmental conditions and allow them to rapidly acclimatize to these conditions. The evolution, structure, and function of repeat proteins have been studied in all kingdoms of life. The presence of repeat proteins is particularly profuse in multicellular organisms in comparison to prokaryotes. The precipitous expansion of repeat proteins in plants is presumed to be through internal tandem duplications. Several repeat protein gene families have been identified in plants. Such as Armadillo (ARM), Ankyrin (ANK), HEAT, Kelch-like repeats, Tetratricopeptide (TPR), Leucine rich repeats (LRR), WD40, and Pentatricopeptide repeats (PPR). The structure and functions of these repeat proteins have been extensively studied in plants suggesting a critical role of these repeating peptides in plant cell physiology, stress and development. In this review, we illustrate the structural, functional, and evolutionary prospects of prolific repeat proteins in plants. PMID:26793205

  19. Stress-responsive expression patterns and functional characterization of cold shock domain proteins in cabbage (Brassica rapa) under abiotic stress conditions.

    PubMed

    Choi, Min Ji; Park, Ye Rin; Park, Su Jung; Kang, Hunseung

    2015-11-01

    Although the functional roles of cold shock domain proteins (CSDPs) have been demonstrated during the growth, development, and stress adaptation of Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), and wheat (Triticum aestivum), the functions of CSDPs in other plants species, including cabbage (Brassica rapa), are largely unknown. To gain insight into the roles of CSDPs in cabbage under stress conditions, the genes encoding CSDPs in cabbage were isolated, and the functional roles of CSDPs in response to environmental stresses were analyzed. Real-time RT-PCR analysis revealed that the levels of BrCSDP transcripts increased during cold, salt, or drought stress, as well as upon ABA treatment. Among the five BrCSDP genes found in the cabbage genome, one CSDP (BRU12051), named BrCSDP3, was unique in that it is localized to the chloroplast as well as to the nucleus. Ectopic expression of BrCSDP3 in Arabidopsis resulted in accelerated seed germination and better seedling growth compared to the wild-type plants under high salt or dehydration stress conditions, and in response to ABA treatment. BrCSDP3 did not affect the splicing of intron-containing genes and processing of rRNAs in the chloroplast. BrCSDP3 had the ability to complement RNA chaperone-deficient Escherichia coli mutant cells under low temperatures as well as DNA- and RNA-melting abilities, suggesting that it possesses RNA chaperone activity. Taken together, these results suggest that BrCSDP3, harboring RNA chaperone activity, plays a role as a positive regulator in seed germination and seedling growth under stress conditions. PMID:26263516

  20. Diastolic function in various forms of left ventricular hypertrophy: contribution of active Doppler stress echo.

    PubMed

    Möckel, M; Störk, T

    1996-11-01

    It has been known for a long time that healthy athletes can develop left ventricular hypertrophy with typical electrocardiographic and echocardiographic findings which lead to the definition of the athlete's heart, as a separate physiological feature. In some cases it is difficult to distinguish between pathological versus physiological myocardial hypertrophy. Diastolic dysfunction is an early sign in the temporal sequence of ischemic events in coronary heart disease. Similar changes occur in other types of heart disease due to arterial hypertension or inflammation processes. Diastolic function is changed even in idiopathic hypertrophic cardiomyopathies. In contrast to these groups of patients, diastolic function remains unchanged or is improved in healthy athletes depending on the type of training (isotonic or isometric exercise). In cases with borderline changes, examinations during physical stress (exercise testing) which provokes an oxygen demand/supply imbalance and consecutively impairs early diastolic filling could clarify if an underlying heart disease is present. Although the physiology of diastolic function is complex, the factors contributing to diastolic disturbances can be differentiated into intrinsic and extrinsic left ventricular (LV) abnormalities. Intrinsic mechanisms include a) impaired LV relaxation, b) increased overall chamber stiffness, c) increased myocardial stiffness and d) increased LV asynchrony. All these factors are part of pathological LV hypertrophy. Factors extrinsic to the LV causing diastolic disorders include a) increased central blood volume, which will increase left ventricular pressure without altering the LV pressure-volume relation, and b) ventricular interaction mediated by pericardial restraint, which may cause a parallel upward shift of the diastolic LV pressure-volume curve. Improved understanding of LV relaxation and filling helps to differentiate pathological and physiological myocardial hypertrophy. Ongoing heart

  1. FUNCTIONAL IMPAIRMENT IN ADULTS WITH PAST POSTTRAUMATIC STRESS DISORDER: FINDINGS FROM PRIMARY CARE

    PubMed Central

    Westphal, Maren; Olfson, Mark; Gameroff, Marc J.; Wickramaratne, Priya; Pilowsky, Daniel J.; Neugebauer, Richard; Lantigua, Rafael; Shea, Steven; Neria, Yuval

    2013-01-01

    Background Although many patients with posttraumatic stress disorder (PTSD) experience a reduction in posttraumatic symptoms over time, little is currently known about the extent of their residual functional impairment. This study examines functional impairment in primary care patients with a history of PTSD as compared to patients with current PTSD, and those who never developed PTSD following exposure to trauma. Methods The sample consisted of 321 trauma-exposed low-income, predominantly Hispanic adults attending a large urban primary care practice. PTSD was assessed with the Lifetime Composite International Diagnostic Interview and other psychiatric disorders with the SCID-I. Physical and mental health-related quality of life was assessed with the Medical Outcome Health Survey (SF-12), and functional impairment with items from the Sheehan Disability Scale and Social Adjustment Scale Self-Report. Results Logistic regression analyses controlling for gender, psychiatric comorbidity, and interpersonal traumas showed that although patients with past PTSD function significantly better than patients with current PTSD, they experience persisting deficits in mental health-related quality of life compared to trauma-exposed patients who never developed PTSD. Overall, results revealed a continuum of severity in psychiatric comorbidity, functioning, and quality of life, with current PTSD associated with the most impairment, never having met criteria for PTSD with the least impairment, and history of PTSD falling in between. Conclusions In this primary care sample, adults with a history of past PTSD but no current PTSD continued to report enduring functional deficits, suggesting a need for ongoing clinical attention. PMID:21681868

  2. Left ventricular systolic and diastolic function during tilt-table positioning and passive heat stress in humans.

    PubMed

    Nelson, Michael D; Altamirano-Diaz, Luis A; Petersen, Stewart R; DeLorey, Darren S; Stickland, Michael K; Thompson, Richard B; Haykowsky, Mark J

    2011-08-01

    The ventricular response to passive heat stress has predominantly been studied in the supine position. It is presently unclear how acute changes in venous return influence ventricular function during heat stress. To address this question, left ventricular (LV) systolic and diastolic function were studied in 17 healthy men (24.3 ± 4.0 yr; mean ± SD), using two-dimensional transthoracic echocardiography with Doppler ultrasound, during tilt-table positioning (supine, 30° head-up tilt, and 30° head-down tilt), under normothermic and passive heat stress (core temperature 0.8 ± 0.1°C above baseline) conditions. The supine heat stress LV volumetric and functional response was consistent with previous reports. Combining head-up tilt with heat stress reduced end-diastolic (25.2 ± 4.1%) and end-systolic (65.4 ± 10.5%) volume from baseline, whereas heart rate (37.7 ± 2.0%), ejection fraction (9.4 ± 2.4%), and LV elastance (37.7 ± 3.6%) increased, and stroke volume (-28.6 ± 9.4%) and early diastolic inflow (-17.5 ± 6.5%) and annular tissue (-35.6 ± 7.0%) velocities were reduced. Combining head-down tilt with heat stress restored end-diastolic volume, whereas LV elastance (16.8 ± 3.2%), ejection fraction (7.2 ± 2.1%), and systolic annular tissue velocities (22.4 ± 5.0%) remained elevated above baseline, and end-systolic volume was reduced (-15.3 ± 3.9%). Stroke volume and the early and late diastolic inflow and annular tissue velocities were unchanged from baseline. This investigation extends previous work by demonstrating increased LV systolic function with heat stress, under varied levels of venous return, and highlights the preload dependency of early diastolic function during passive heat stress. PMID:21536844

  3. The effects of stress on splenic immune function are mediated by the splenic nerve.

    PubMed

    Wan, W; Vriend, C Y; Wetmore, L; Gartner, J G; Greenberg, A H; Nance, D M

    1993-01-01

    Intermittent footshock (FS) suppresses immune function of spleen cells. To determine if the autonomic nervous system mediates this immunosuppression in spleen cells, we tested whether cutting the splenic nerve, which depletes splenic norepinephrine levels by 98-100% and eliminates catecholamine fibers, blocks the effects of stress. Splenic nerve sections, sham operations, or no surgery were performed on male Sprague-Dawley rats. Ten days later, rats were injected with sheep red blood cells (SRBC). Three days later, rats were placed in a chamber equipped with a shock grid. Foot shock (1.6 mA) was administered for 5 s on a VI 3.5 min schedule for 60 min. Each FS was preceded by a 15-s warning tone. Controls were treated identically except for the FS. The next day spleen cells were harvested and the number of IgM plaque-forming cells (PFCs) determined. For the sham and unoperated control animals, the number of PFCs was reduced for the stressed animals relative to the nonstressed controls, and there was no effect of the sham surgeries. In contrast, there was no difference between the stressed and nonstressed groups in which the splenic nerve had been sectioned, and their PFC response was comparable to the controls. Next we examined the effects of FS on the proliferative response to mitogens (PHA and ConA) following splenic nerve sections or sham operations. One week following surgery, animals were given a 60-min session of FS or exposed to the chamber/tone without FS. Rats were then killed, spleens harvested, and the proliferative response to mitogens determined.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8420618

  4. Oxidative stress modulates mitochondrial failure and cyclophilin D function in X-linked adrenoleukodystrophy

    PubMed Central

    López-Erauskin, Jone; Galino, Jorge; Bianchi, Patrizia; Fourcade, Stéphane; Andreu, Antoni L.; Ferrer, Isidre; Muñoz-Pinedo, Cristina

    2012-01-01

    A common process associated with oxidative stress and severe mitochondrial impairment is the opening of the mitochondrial permeability transition pore, as described in many neurodegenerative diseases. Thus, inhibition of mitochondrial permeability transition pore opening represents a potential target for inhibiting mitochondrial-driven cell death. Among the mitochondrial permeability transition pore components, cyclophilin D is the most studied and has been found increased under pathological conditions. Here, we have used in vitro and in vivo models of X-linked adrenoleukodystrophy to investigate the relationship between the mitochondrial permeability transition pore opening and redox homeostasis. X-linked adrenoleukodystrophy is a neurodegenerative condition caused by loss of function of the peroxisomal ABCD1 transporter, in which oxidative stress plays a pivotal role. In this study, we provide evidence of impaired mitochondrial metabolism in a peroxisomal disease, as fibroblasts in patients with X-linked adrenoleukodystrophy cannot survive when forced to rely on mitochondrial energy production, i.e. on incubation in galactose. Oxidative stress induced under galactose conditions leads to mitochondrial damage in the form of mitochondrial inner membrane potential dissipation, ATP drop and necrotic cell death, together with increased levels of oxidative modifications in cyclophilin D protein. Moreover, we show increased expression levels of cyclophilin D in the affected zones of brains in patients with adrenomyeloneuropathy, in spinal cord of a mouse model of X-linked adrenoleukodystrophy (Abcd1-null mice) and in fibroblasts from patients with X-linked adrenoleukodystrophy. Notably, treatment with antioxidants rescues mitochondrial damage markers in fibroblasts from patients with X-linked adrenoleukodystrophy, including cyclophilin D oxidative modifications, and reverses cyclophilin D induction in vitro and in vivo. These findings provide mechanistic insight into the

  5. Neonatal handling of Amazon parrots alters the stress response and immune function.

    PubMed

    Collette; Millam; Klasing; Wakenell

    2000-03-01

    The influence of neonatal handling on behavior and immune function was assessed in Orange-winged Amazon parrots (Amazona amazonica). Chicks (n=11) were gently handled daily from 25 days of age until 38 days post-fledging, while control chicks (n=9) were not handled. At 10 days post-fledging ( approximately 66 days of age), chicks were given tests to evaluate tameness (e.g., willingness to perch on an offered finger). They were then restrained for 10 min, either by being held while perching (handled group) or, because they would not perch, by being restrained in a towel (nonhandled group). Serum corticosterone levels were measured and immune status was assessed by: the delayed-type hypersensitivity (DTH) response to phytohemagglutinin-P (PH-P) injection; the humoral response to a killed Newcastle disease virus (NDV) challenge; and heterophil:lymphocyte ratio (H:L). Handled chicks were tamer by all measures of tameness. DTH was greater in nonhandled chicks (Pstressful. The greater DTH response of nonhandled chicks suggests that either their DTH response was enhanced by the acute stress of being restrained in a towel, and/or the DTH response of handled chicks was suppressed as a result of the repeated physiologic stress from handling during the neonatal period. In either event, handling produced marked differences in response to types of restraint that would be typically encountered in the husbandry of Amazons in captivity. PMID:10700631

  6. DNA Replication Stress Phosphoproteome Profiles Reveal Novel Functional Phosphorylation Sites on Xrs2 in Saccharomyces cerevisiae.

    PubMed

    Huang, Dongqing; Piening, Brian D; Kennedy, Jacob J; Lin, Chenwei; Jones-Weinert, Corey W; Yan, Ping; Paulovich, Amanda G

    2016-05-01

    In response to replication stress, a phospho-signaling cascade is activated and required for coordination of DNA repair and replication of damaged templates (intra-S-phase checkpoint) . How phospho-signaling coordinates the DNA replication stress response is largely unknown. We employed state-of-the-art liquid chromatography tandem-mass spectrometry (LC-MS/MS) approaches to generate high-coverage and quantitative proteomic and phospho-proteomic profiles during replication stress in yeast, induced by continuous exposure to the DNA alkylating agent methyl methanesulfonate (MMS) . We identified 32,057 unique peptides representing the products of 4296 genes and 22,061 unique phosphopeptides representing the products of 3183 genes. A total of 542 phosphopeptides (mapping to 339 genes) demonstrated an abundance change of greater than or equal to twofold in response to MMS. The screen enabled detection of nearly all of the proteins known to be involved in the DNA damage response, as well as many novel MMS-induced phosphorylations. We assessed the functional importance of a subset of key phosphosites by engineering a panel of phosphosite mutants in which an amino acid substitution prevents phosphorylation. In total, we successfully mutated 15 MMS-responsive phosphorylation sites in seven representative genes including APN1 (base excision repair); CTF4 and TOF1 (checkpoint and sister-chromatid cohesion); MPH1 (resolution of homologous recombination intermediates); RAD50 and XRS2 (MRX complex); and RAD18 (PRR). All of these phosphorylation site mutants exhibited MMS sensitivity, indicating an important role in protecting cells from DNA damage. In particular, we identified MMS-induced phosphorylation sites on Xrs2 that are required for MMS resistance in the absence of the MRX activator, Sae2, and that affect telomere maintenance. PMID:27017623

  7. Effects of Temperament, Symptom Severity and Level of Functioning on Maternal Stress in Greek Children and Youth with ASD

    ERIC Educational Resources Information Center

    Konstantareas, M. Mary; Papageorgiou, Vaya

    2006-01-01

    This study examined the effect of child temperament, symptom severity, verbal ability and level of functioning on maternal stress in 43 Greek mothers of children and young people with autism spectrum disorder. Symptom severity was assessed by the CARS, level of functioning by the PEP, temperament by the Dimensions of Temperament Scale (DOTS-R) and…

  8. Spongionella Secondary Metabolites Protect Mitochondrial Function in Cortical Neurons against Oxidative Stress

    PubMed Central

    Leirós, Marta; Sánchez, Jon A.; Alonso, Eva; Rateb, Mostafa E.; Houssen, Wael E.; Ebel, Rainer; Jaspars, Marcel; Alfonso, Amparo; Botana, Luis M.

    2014-01-01

    The marine habitat provides a large number of structurally-diverse bioactive compounds for drug development. Marine sponges have been studied over many years and are found to be a rich source of these bioactive chemicals. This study is focused on the evaluation of the activity of six diterpene derivatives isolated from Spongionella sp. on mitochondrial function using an oxidative in vitro stress model. The test compounds include the Gracilins (A, H, K, J and L) and tetrahydroaplysulphurin-1. Compounds were co-incubated with hydrogen peroxide for 12 hours to determine their protective capacities and their effect on markers of apoptosis and Nrf2/ARE pathways was evaluated. Results conclude that Gracilins preserve neurons against oxidative damage, and that in particular, tetrahydroaplysulphurin-1 shows a complete neuroprotective activity. Oxidative stress is linked to mitochondrial dysfunction and consequently to neurodegenerative disorders like Parkinson and Alzheimer diseases, Friedreich ataxia or Amyotrophic lateral sclerosis. This neuroprotection against oxidation conditions suggest that these metabolites could be interesting lead candidates in drug development for neurodegenerative diseases. PMID:24473170

  9. Delineation of WRN Helicase Function with EXO1 in the Replicational Stress Response

    PubMed Central

    Aggarwal, Monika; Sommers, Joshua A.; Morris, Christa; Brosh, Robert M.

    2010-01-01

    The WRN gene defective in the premature aging disorder Werner syndrome encodes a helicase/exonuclease. We examined the ability of WRN to rescue DNA damage sensitivity of a yeast mutant defective in the Rad50 subunit of Mre11-Rad50- Xrs2 nuclease complex implicated in homologous recombination repair. Genetic studies revealed WRN operates in a yEXO1-dependent pathway to rescue rad50 sensitivity to methylmethane sulfonate (MMS) and prevent mitotic catastrophe. WRN helicase, but not exonuclease, is required for MMS resistance. WRN missense mutations in helicase or RecQ C-terminal domains interfered with the ability of WRN to rescue rad50 MMS sensitivity. WRN does not rescue rad50 ionizing radiation (IR) sensitivity, suggesting that WRN, in collaboration with yEXO1, is tailored to relieve replicational stress imposed by alkylated base damage. WRN and yEXO1 are associated with each other in vivo. Purified WRN stimulates hEXO1 nuclease activity on DNA substrates associated with a stalled or regressed replication fork. We propose WRN helicase operates in an EXO1-dependent pathway to help cells survive replicational stress. In contrast to WRN, BLM helicase defective in Bloom’s syndrome failed to rescue rad50 MMS sensitivity, but partially restored IR resistance, suggesting a delineation of function by the human RecQ helicases. PMID:20447876

  10. Relationship of radionuclide indexes of cardiac function during interventions: volume loading, afterload stress, exercise, and pacing

    SciTech Connect

    Slutsky, R.A.

    1983-04-01

    We compared three radionuclide index of cardiac function: 1) the ejection fraction (EF), 2) the mean ejection rate (ER), and 3) the mean velocity of circumferential fiber shortening (MVCF) during volume loading, phenylephrine hydrochloride stress, exercise, and atrial pacing. All behaved in a similar (linear) fashion, allowing appropriate hemodynamic conclusions to be drawn using either index. During atrial pacing, the ejection fraction declined when velocity indexes increased, suggesting that the ejection fraction may not be a suitable index to characterize alterations in inotropic state during rapid alterations in heart rate, particular in the absence of angina pectoris. This may result from the reductions in cardiac volume for the duration of pacing, where the velocity index is preserved. In most circumstances excluding atrial pacing, ejection fraction during interventions is an adequate index of the change of myocardial contractile state. Overall, radionuclide angiography is an excellent technique to characterize acute hemodynamic interventions, with ejection fraction, in general, the simplest and most reliable of cardiac indexes during stress interventions.

  11. Convergent functional genomic studies of ω-3 fatty acids in stress reactivity, bipolar disorder and alcoholism.

    PubMed

    Le-Niculescu, H; Case, N J; Hulvershorn, L; Patel, S D; Bowker, D; Gupta, J; Bell, R; Edenberg, H J; Tsuang, M T; Kuczenski, R; Geyer, M A; Rodd, Z A; Niculescu, A B

    2011-01-01

    Omega-3 fatty acids have been proposed as an adjuvant treatment option in psychiatric disorders. Given their other health benefits and their relative lack of toxicity, teratogenicity and side effects, they may be particularly useful in children and in females of child-bearing age, especially during pregnancy and postpartum. A comprehensive mechanistic understanding of their effects is needed. Here we report translational studies demonstrating the phenotypic normalization and gene expression effects of dietary omega-3 fatty acids, specifically docosahexaenoic acid (DHA), in a stress-reactive knockout mouse model of bipolar disorder and co-morbid alcoholism, using a bioinformatic convergent functional genomics approach integrating animal model and human data to prioritize disease-relevant genes. Additionally, to validate at a behavioral level the novel observed effects on decreasing alcohol consumption, we also tested the effects of DHA in an independent animal model, alcohol-preferring (P) rats, a well-established animal model of alcoholism. Our studies uncover sex differences, brain region-specific effects and blood biomarkers that may underpin the effects of DHA. Of note, DHA modulates some of the same genes targeted by current psychotropic medications, as well as increases myelin-related gene expression. Myelin-related gene expression decrease is a common, if nonspecific, denominator of neuropsychiatric disorders. In conclusion, our work supports the potential utility of omega-3 fatty acids, specifically DHA, for a spectrum of psychiatric disorders such as stress disorders, bipolar disorder, alcoholism and beyond. PMID:22832392

  12. Perivascular Mast Cells Govern Shear Stress-Induced Arteriogenesis by Orchestrating Leukocyte Function.

    PubMed

    Chillo, Omary; Kleinert, Eike Christian; Lautz, Thomas; Lasch, Manuel; Pagel, Judith-Irina; Heun, Yvonn; Troidl, Kerstin; Fischer, Silvia; Caballero-Martinez, Amelia; Mauer, Annika; Kurz, Angela R M; Assmann, Gerald; Rehberg, Markus; Kanse, Sandip M; Nieswandt, Bernhard; Walzog, Barbara; Reichel, Christoph A; Mannell, Hanna; Preissner, Klaus T; Deindl, Elisabeth

    2016-08-23

    The body has the capacity to compensate for an occluded artery by creating a natural bypass upon increased fluid shear stress. How this mechanical force is translated into collateral artery growth (arteriogenesis) is unresolved. We show that extravasation of neutrophils mediated by the platelet receptor GPIbα and uPA results in Nox2-derived reactive oxygen radicals, which activate perivascular mast cells. These c-kit(+)/CXCR-4(+) cells stimulate arteriogenesis by recruiting additional neutrophils as well as growth-promoting monocytes and T cells. Additionally, mast cells may directly contribute to vascular remodeling and vascular cell proliferation through increased MMP activity and by supplying growth-promoting factors. Boosting mast cell recruitment and activation effectively promotes arteriogenesis, thereby protecting tissue from severe ischemic damage. We thus find that perivascular mast cells are central regulators of shear stress-induced arteriogenesis by orchestrating leukocyte function and growth factor/cytokine release, thus providing a therapeutic target for treatment of vascular occlusive diseases. PMID:27524614

  13. Plant phospholipases D and C and their diverse functions in stress responses.

    PubMed

    Hong, Yueyun; Zhao, Jian; Guo, Liang; Kim, Sang-Chul; Deng, Xianjun; Wang, Geliang; Zhang, Gaoyang; Li, Maoyin; Wang, Xuemin

    2016-04-01

    Phospholipases D (PLD) and C (PLC) hydrolyze the phosphodiesteric linkages of the head group of membrane phospholipids. PLDs and PLCs in plants occur in different forms: the calcium-dependent phospholipid binding domain-containing PLDs (C2-PLDs), the plekstrin homology and phox homology domain-containing PLDs (PX/PH-PLDs), phosphoinositide-specific PLC (PI-PLC), and non-specific PLC (NPC). They differ in structures, substrate selectivities, cofactor requirements, and/or reaction conditions. These enzymes and their reaction products, such as phosphatidic acid (PA), diacylglycerol (DAG), and inositol polyphosphates, play important, multifaceted roles in plant response to abiotic and biotic stresses. Here, we review biochemical properties, cellular effects, and physiological functions of PLDs and PLCs, particularly in the context of their roles in stress response along with advances made on the role of PA and DAG in cell signaling in plants. The mechanism of actions, including those common and distinguishable among different PLDs and PLCs, will also be discussed. PMID:26783886

  14. NFAT5 in cellular adaptation to hypertonic stress - regulations and functional significance.

    PubMed

    Cheung, Chris Yk; Ko, Ben Cb

    2013-01-01

    The Nuclear Factor of Activated T Cells-5 (NFAT5), also known as OREBP or TonEBP, is a member of the nuclear factors of the activated T cells family of transcription factors. It is also the only known tonicity-regulated transcription factor in mammals. NFAT5 was initially known for its role in the hypertonic kidney inner medulla for orchestrating a genetic program to restore the cellular homeostasis. Emerging evidence, however, suggests that NFAT5 might play a more diverse functional role, including a pivotal role in blood pressure regulation and the development of autoimmune diseases. Despite the growing significance of NFAT5 in physiology and diseases, our understanding of how its activity is regulated remains very limited. Furthermore, how changes in tonicities are converted into functional outputs via NFAT5 remains elusive. Therefore, this review aims to summarize our current knowledge on the functional roles of NFAT5 in osmotic stress adaptation and the signaling pathways that regulate its activity. PMID:23618372

  15. Differential Contributions of Nonmuscle Myosin II Isoforms and Functional Domains to Stress Fiber Mechanics.

    PubMed

    Chang, Ching-Wei; Kumar, Sanjay

    2015-01-01

    While is widely acknowledged that nonmuscle myosin II (NMMII) enables stress fibers (SFs) to generate traction forces against the extracellular matrix, little is known about how specific NMMII isoforms and functional domains contribute to SF mechanics. Here we combine biophotonic and genetic approaches to address these open questions. First, we suppress the NMMII isoforms MIIA and MIIB and apply femtosecond laser nanosurgery to ablate and investigate the viscoelastic retraction of individual SFs. SF retraction dynamics associated with MIIA and MIIB suppression qualitatively phenocopy our earlier measurements in the setting of Rho kinase (ROCK) and myosin light chain kinase (MLCK) inhibition, respectively. Furthermore, fluorescence imaging and photobleaching recovery reveal that MIIA and MIIB are enriched in and more stably localize to ROCK- and MLCK-controlled central and peripheral SFs, respectively. Additional domain-mapping studies surprisingly reveal that deletion of the head domain speeds SF retraction, which we ascribe to reduced drag from actomyosin crosslinking and frictional losses. We propose a model in which ROCK/MIIA and MLCK/MIIB functionally regulate common pools of SFs, with MIIA crosslinking and motor functions jointly contributing to SF retraction dynamics and cellular traction forces. PMID:26336830

  16. Hsp72 chaperone function is dispensable for protection against stress-induced apoptosis.

    PubMed

    Chow, Ari M; Steel, Rohan; Anderson, Robin L

    2009-05-01

    In addition to its role as a molecular chaperone, heat shock protein 72 (Hsp72) protects cells against a wide range of apoptosis inducing stresses. However, it is unclear if these two roles are functionally related or whether Hsp72 inhibits apoptosis by a mechanism independent of chaperone activity. The N-terminal adenosine triphosphatase domain, substrate-binding domain and the C-terminal EEVD regulatory motif of Hsp72 are all essential for chaperone activity. In this study, we show that Hsp72 mutants with a functional substrate-binding domain but lacking chaperone activity retain their ability to protect cells against apoptosis induced by heat and tumor necrosis factor alpha. In contrast, a deletion mutant lacking a functional substrate-binding domain has no protective capacity. The ability of the Hsp72 substrate-binding domain to inhibit apoptosis independent of the regulatory effects of the adenosine triphosphate-binding domain indicates that the inhibition of apoptosis may involve a stable binding interaction with a regulatory substrate rather than Hsp72 chaperone activity. PMID:18819021

  17. Attributing functions to ectomycorrhizal fungal identities in assemblages for nitrogen acquisition under stress

    PubMed Central

    Pena, Rodica; Polle, Andrea

    2014-01-01

    Mycorrhizal fungi have a key role in nitrogen (N) cycling, particularly in boreal and temperate ecosystems. However, the significance of ectomycorrhizal fungal (EMF) diversity for this important ecosystem function is unknown. Here, EMF taxon-specific N uptake was analyzed via 15N isotope enrichment in complex root-associated assemblages and non-mycorrhizal root tips in controlled experiments. Specific 15N enrichment in ectomycorrhizas, which represents the N influx and export, as well as the exchange of 15N with the N pool of the root tip, was dependent on the fungal identity. Light or water deprivation revealed interspecific response diversity for N uptake. Partial taxon-specific N fluxes for ectomycorrhizas were assessed, and the benefits of EMF assemblages for plant N nutrition were estimated. We demonstrated that ectomycorrhizal assemblages provide advantages for inorganic N uptake compared with non-mycorrhizal roots under environmental constraints but not for unstressed plants. These benefits were realized via stress activation of distinct EMF taxa, which suggests significant functional diversity within EMF assemblages. We developed and validated a model that predicts net N flux into the plant based on taxon-specific 15N enrichment in ectomycorrhizal root tips. These results open a new avenue to characterize the functional traits of EMF taxa in complex communities. PMID:24030593

  18. Critical Role of Tumor Microenvironment in Shaping NK Cell Functions: Implication of Hypoxic Stress.

    PubMed

    Hasmim, Meriem; Messai, Yosra; Ziani, Linda; Thiery, Jerome; Bouhris, Jean-Henri; Noman, Muhammad Zaeem; Chouaib, Salem

    2015-01-01

    Blurring the boundary between innate and adaptive immune system, natural killer (NK) cells, a key component of the innate immunity, are recognized as potent anticancer mediators. Extensive studies have been detailed on how NK cells get activated and recognize cancer cells. In contrast, few studies have been focused on how tumor microenvironment-mediated immunosubversion and immunoselection of tumor-resistant variants may impair NK cell function. Accumulating evidences indicate that several cell subsets (macrophages, myeloid-derived suppressive cells, T regulatory cells, dendritic cells, cancer-associated fibroblasts, and tumor cells), their secreted factors, as well as metabolic components (i.e., hypoxia) have immunosuppressive roles in the tumor microenvironment and are able to condition NK cells to become anergic. In this review, we will describe how NK cells react with different stromal cells in the tumor microenvironment. This will be followed by a discussion on the role of hypoxic stress in the regulation of NK cell functions. The aim of this review is to provide a better understanding of how the tumor microenvironment impairs NK cell functions, thereby limiting the use of NK cell-based therapy, and we will attempt to suggest more efficient tools to establish a more favorable tumor microenvironment to boost NK cell cytotoxicity and control tumor progression. PMID:26441986

  19. Altered resting-state functional activity in posttraumatic stress disorder: A quantitative meta-analysis

    PubMed Central

    Wang, Ting; Liu, Jia; Zhang, Junran; Zhan, Wang; Li, Lei; Wu, Min; Huang, Hua; Zhu, Hongyan; Kemp, Graham J.; Gong, Qiyong

    2016-01-01

    Many functional neuroimaging studies have reported differential patterns of spontaneous brain activity in posttraumatic stress disorder (PTSD), but the findings are inconsistent and have not so far been quantitatively reviewed. The present study set out to determine consistent, specific regional brain activity alterations in PTSD, using the Effect Size Signed Differential Mapping technique to conduct a quantitative meta-analysis of resting-state functional neuroimaging studies of PTSD that used either a non-trauma (NTC) or a trauma-exposed (TEC) comparison control group. Fifteen functional neuroimaging studies were included, comparing 286 PTSDs, 203 TECs and 155 NTCs. Compared with NTC, PTSD patients showed hyperactivity in the right anterior insula and bilateral cerebellum, and hypoactivity in the dorsal medial prefrontal cortex (mPFC); compared with TEC, PTSD showed hyperactivity in the ventral mPFC. The pooled meta-analysis showed hypoactivity in the posterior insula, superior temporal, and Heschl’s gyrus in PTSD. Additionally, subgroup meta-analysis (non-medicated subjects vs. NTC) identified abnormal activation in the prefrontal-limbic system. In meta-regression analyses, mean illness duration was positively associated with activity in the right cerebellum (PTSD vs. NTC), and illness severity was negatively associated with activity in the right lingual gyrus (PTSD vs. TEC). PMID:27251865

  20. Perfusion deficits and functional connectivity alterations in patients with post-traumatic stress disorder

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing

    2016-03-01

    To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.

  1. Functions of health fatalism: fatalistic talk as face saving, uncertainty management, stress relief and sense making.

    PubMed

    Keeley, Bethany; Wright, Lanelle; Condit, Celeste M

    2009-07-01

    Much research on fatalism assumes that fatalistic statements represent a global outlook that conflicts with belief in the efficacy of health behaviours. Other scholars have suggested a more contextual approach, suggesting that fatalism fulfils personal and social functions. This study analyses 96 in-depth lay interviews in the US, most with low-income members of the general public, about four diseases: heart disease, lung cancer, diabetes and depression. Within these interviews, fatalistic statements always occurred alongside statements endorsing the utility of behaviours for protecting health. This usage pattern suggests that these statements may have useful functions, rather than being simply a repudiation of the utility of health choices. We examine four functions that are suggested by previous researchers or by the participants' comments: stress relief, uncertainty management, sense making and (less strongly) face saving. As these themes indicate, individuals often make fatalistic statements to express an understanding of locally or broadly limiting factors for health efficacy, including genes, spiritual agents, prior behaviours, personality, and other factors. PMID:19392939

  2. Altered resting-state functional activity in posttraumatic stress disorder: A quantitative meta-analysis.

    PubMed

    Wang, Ting; Liu, Jia; Zhang, Junran; Zhan, Wang; Li, Lei; Wu, Min; Huang, Hua; Zhu, Hongyan; Kemp, Graham J; Gong, Qiyong

    2016-01-01

    Many functional neuroimaging studies have reported differential patterns of spontaneous brain activity in posttraumatic stress disorder (PTSD), but the findings are inconsistent and have not so far been quantitatively reviewed. The present study set out to determine consistent, specific regional brain activity alterations in PTSD, using the Effect Size Signed Differential Mapping technique to conduct a quantitative meta-analysis of resting-state functional neuroimaging studies of PTSD that used either a non-trauma (NTC) or a trauma-exposed (TEC) comparison control group. Fifteen functional neuroimaging studies were included, comparing 286 PTSDs, 203 TECs and 155 NTCs. Compared with NTC, PTSD patients showed hyperactivity in the right anterior insula and bilateral cerebellum, and hypoactivity in the dorsal medial prefrontal cortex (mPFC); compared with TEC, PTSD showed hyperactivity in the ventral mPFC. The pooled meta-analysis showed hypoactivity in the posterior insula, superior temporal, and Heschl's gyrus in PTSD. Additionally, subgroup meta-analysis (non-medicated subjects vs. NTC) identified abnormal activation in the prefrontal-limbic system. In meta-regression analyses, mean illness duration was positively associated with activity in the right cerebellum (PTSD vs. NTC), and illness severity was negatively associated with activity in the right lingual gyrus (PTSD vs. TEC). PMID:27251865

  3. Attributing functions to ectomycorrhizal fungal identities in assemblages for nitrogen acquisition under stress.

    PubMed

    Pena, Rodica; Polle, Andrea

    2014-02-01

    Mycorrhizal fungi have a key role in nitrogen (N) cycling, particularly in boreal and temperate ecosystems. However, the significance of ectomycorrhizal fungal (EMF) diversity for this important ecosystem function is unknown. Here, EMF taxon-specific N uptake was analyzed via (15)N isotope enrichment in complex root-associated assemblages and non-mycorrhizal root tips in controlled experiments. Specific (15)N enrichment in ectomycorrhizas, which represents the N influx and export, as well as the exchange of (15)N with the N pool of the root tip, was dependent on the fungal identity. Light or water deprivation revealed interspecific response diversity for N uptake. Partial taxon-specific N fluxes for ectomycorrhizas were assessed, and the benefits of EMF assemblages for plant N nutrition were estimated. We demonstrated that ectomycorrhizal assemblages provide advantages for inorganic N uptake compared with non-mycorrhizal roots under environmental constraints but not for unstressed plants. These benefits were realized via stress activation of distinct EMF taxa, which suggests significant functional diversity within EMF assemblages. We developed and validated a model that predicts net N flux into the plant based on taxon-specific (15)N enrichment in ectomycorrhizal root tips. These results open a new avenue to characterize the functional traits of EMF taxa in complex communities. PMID:24030593

  4. Critical Role of Tumor Microenvironment in Shaping NK Cell Functions: Implication of Hypoxic Stress

    PubMed Central

    Hasmim, Meriem; Messai, Yosra; Ziani, Linda; Thiery, Jerome; Bouhris, Jean-Henri; Noman, Muhammad Zaeem; Chouaib, Salem

    2015-01-01

    Blurring the boundary between innate and adaptive immune system, natural killer (NK) cells, a key component of the innate immunity, are recognized as potent anticancer mediators. Extensive studies have been detailed on how NK cells get activated and recognize cancer cells. In contrast, few studies have been focused on how tumor microenvironment-mediated immunosubversion and immunoselection of tumor-resistant variants may impair NK cell function. Accumulating evidences indicate that several cell subsets (macrophages, myeloid-derived suppressive cells, T regulatory cells, dendritic cells, cancer-associated fibroblasts, and tumor cells), their secreted factors, as well as metabolic components (i.e., hypoxia) have immunosuppressive roles in the tumor microenvironment and are able to condition NK cells to become anergic. In this review, we will describe how NK cells react with different stromal cells in the tumor microenvironment. This will be followed by a discussion on the role of hypoxic stress in the regulation of NK cell functions. The aim of this review is to provide a better understanding of how the tumor microenvironment impairs NK cell functions, thereby limiting the use of NK cell-based therapy, and we will attempt to suggest more efficient tools to establish a more favorable tumor microenvironment to boost NK cell cytotoxicity and control tumor progression. PMID:26441986

  5. Functional Immune Alterations, Latent Herpesvirus Reactivation, Physiological Stress and Clinical Incidence Onboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Kunz, Hawley; Mehta, Satish; Stowe, Ray; Ploutz-Snyder, Robert; Quiriarte, Heather; Chouker, Alexander; Pierson, Duane

    2016-01-01

    This study (OpNom 'Functional Immune') will be a comprehensive immunity Flight Definition investigation that will use longitudinal repeated measures to assess various aspects of immunity and viral reactivation during long-duration spaceflight. This proposal builds on the successful sampling architecture of the former Integrated Immune flight study, which for the first time returned ambient, live blood samples from space to allow functional assays. Blood (ambient, live) and saliva samples will be collected before, during, and following spaceflight. Previously uninvestigated live cell assays will be performed to assess cellular function during spaceflight. Specialized preservatives will be utilized to assess comprehensive immunophenotype, gene expression and proteomics. Measures of inflammation, stress, antimicrobial activity, etc. will be assessed in blood, saliva, and/or urine. The reactivation of a panel of herpesviruses will be assessed both during flight, and post-flight until shedding resolves. Array technology will be utilized to allow maximal information to be derived from minimal in-flight samples. This study will be a hybrid of NASA internal scientists and researchers external to NASA. The NASA 'Core' science package and implementation strategy was selected and approved in 2014. Via NRA, the solicitation for external participation, with science directed to comply with the parent study sampling architecture, is in progress

  6. Differential Contributions of Nonmuscle Myosin II Isoforms and Functional Domains to Stress Fiber Mechanics

    PubMed Central

    Chang, Ching-Wei; Kumar, Sanjay

    2015-01-01

    While is widely acknowledged that nonmuscle myosin II (NMMII) enables stress fibers (SFs) to generate traction forces against the extracellular matrix, little is known about how specific NMMII isoforms and functional domains contribute to SF mechanics. Here we combine biophotonic and genetic approaches to address these open questions. First, we suppress the NMMII isoforms MIIA and MIIB and apply femtosecond laser nanosurgery to ablate and investigate the viscoelastic retraction of individual SFs. SF retraction dynamics associated with MIIA and MIIB suppression qualitatively phenocopy our earlier measurements in the setting of Rho kinase (ROCK) and myosin light chain kinase (MLCK) inhibition, respectively. Furthermore, fluorescence imaging and photobleaching recovery reveal that MIIA and MIIB are enriched in and more stably localize to ROCK- and MLCK-controlled central and peripheral SFs, respectively. Additional domain-mapping studies surprisingly reveal that deletion of the head domain speeds SF retraction, which we ascribe to reduced drag from actomyosin crosslinking and frictional losses. We propose a model in which ROCK/MIIA and MLCK/MIIB functionally regulate common pools of SFs, with MIIA crosslinking and motor functions jointly contributing to SF retraction dynamics and cellular traction forces. PMID:26336830

  7. Viewing Nature Scenes Positively Affects Recovery of Autonomic Function Following Acute-Mental Stress

    PubMed Central

    2013-01-01

    A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor. PMID:23590163

  8. The maternal brain under stress: Consequences for adaptive peripartum plasticity and its potential functional implications.

    PubMed

    Slattery, David A; Hillerer, Katharina M

    2016-04-01

    The peripartum period represents a time during which all mammalian species undergo substantial physiological and behavioural changes, which prepare the female for the demands of motherhood. In addition to behavioural and physiological alterations, numerous brain regions, such as the medial prefrontal cortex, olfactory bulb, medial amygdala and hippocampus are subject to substantial peripartum-associated neuronal, dendritic and synaptic plasticity. These changes, which are temporally- and spatially-distinct, are strongly influenced by gonadal and adrenal hormones, such as estrogen and cortisol/corticosterone, which undergo dramatic fluctuations across this period. In this review, we describe our current knowledge regarding these plasticity changes and describe how stress affects such normal adaptations. Finally, we discuss the mechanisms potentially underlying these neuronal, dendritic and synaptic changes and their functional relevance for the mother and her offspring. PMID:26828151

  9. Numerical Analysis of Stress Intensity Factors in Three-Dimensional Functionally Graded Materials

    SciTech Connect

    Guo Licheng; Wu Linzhi; Yu Hongjun

    2008-02-15

    In this paper, a finite element method based on nonhomogeneous elements is used to study crack problems in three-dimensional (3D) functionally graded materials (FGMs). Since the actual material properties at each integral point are employed in the integration during formation of the element stiffness matrix, each element can have nonhomogeneous material properties. By this method, the number of elements is reduced and the meshing effort for the structure is simplified. Therefore, the modeling process for numerical simulation of fracture behavior in 3D FGMs is greatly simplified. The crack front characteristics of Mode-I edge penetrable crack in 3D FGM specimens are studied under uniform tension loading. The influence of material nonhomogeneity constant and geometric parameters on the stress intensity factors (SIFs) of the 3D FGM specimens are investigated.

  10. Neuropsychological functioning in posttraumatic stress disorder following forced displacement in older adults and their offspring.

    PubMed

    Jelinek, Lena; Wittekind, Charlotte E; Moritz, Steffen; Kellner, Michael; Muhtz, Christoph

    2013-12-15

    The aim of the present study was to investigate neuropsychological performance in an untried trauma sample of older adults displaced during childhood at the end of World War II (WWII) with and without posttraumatic stress disorder (PTSD) as well as transgenerational effects of trauma and PTSD on their offspring. Displaced older adults with (n=20) and without PTSD (n=24) and nondisplaced healthy individuals (n=11) as well as one of their respective offspring were assessed with a large battery of cognitive tests (primarily targeting memory functioning). No evidence for deficits in neuropsychological performance was found in the aging group of displaced people with PTSD. Moreover, no group difference emerged in the offspring groups. Findings may be interpreted as first evidence for a rather resilient PTSD group of older adults that is available for assessment 60 years after displacement. PMID:23896354

  11. Posttraumatic stress disorder and current relationship functioning among World War II ex-prisoners of war.

    PubMed

    Cook, Joan M; Riggs, David S; Thompson, Richard; Coyne, James C; Sheikh, Javaid I

    2004-03-01

    This study examined the association of posttraumatic stress disorder (PTSD) with the quality of intimate relationships among present-day male World War II ex-prisoners of war (POWs). Ex-POWs had considerable marital stability; those with PTSD were no less likely to be in an intimate relationship. Ex-POWs in an intimate relationship who had PTSD (N=125 ) were compared with ex-POWs in a relationship who did not have PTSD (N=206). Marital functioning was within a range expected for persons without traumatic exposure. Yet, over 30% of those with PTSD reported relationship problems compared with only 11% of those without PTSD. Ex-POWs with PTSD reported poorer adjustment and communication with their partners and more difficulties with intimacy. Emotional numbing was significantly associated with relationship difficulties independent of other symptom complexes and severity of PTSD. Implications for clinical practice are discussed. PMID:14992608

  12. Dysregulated Hypothalamic–Pituitary–Adrenal Axis Function Contributes to Altered Endocrine and Neurobehavioral Responses to Acute Stress

    PubMed Central

    Kinlein, Scott A.; Wilson, Christopher D.; Karatsoreos, Ilia N.

    2015-01-01

    Organisms react to environmental challenges by activating a coordinated set of brain–body responses known as the stress response. These physiological and behavioral countermeasures are, in large part, regulated by the neuroendocrine hypothalamic–pituitary–adrenal (HPA) axis. Normal functioning of the HPA axis ensures that an organism responds appropriately to altered environmental demands, representing an essential system to promote survival. Over the past several decades, increasing evidence supports the hypothesis that disruption of the HPA axis can lead to dysregulated stress response phenotypes, exacting a physiological cost on the organism commonly referred to as allostatic load. Furthermore, it has been recognized that high allostatic load can contribute to increased vulnerability of the organism to further challenges. This observation leads to the notion that disrupted HPA function and resulting inappropriate responses to stressors may underlie many neuropsychiatric disorders, including depression and anxiety. In the present set of studies, we investigate the role of both the normally functioning and disrupted HPA axis in the endocrine, neural, and behavioral responses to acute stress. Using a model of non-invasive chronic corticosterone treatment in mice, we show that dysregulating the normal function of the HPA leads to a mismatch between the hormonal and neural response to acute stress, resulting in abnormal behavioral coping strategies. We believe this model can be leveraged to tease apart the mechanisms by which altered HPA function contributes to neurobehavioral dysregulation in response to acute stress. PMID:25821436

  13. Gene expression and function involved in polyol biosynthesis of Trichosporonoides megachiliensis under hyper-osmotic stress.

    PubMed

    Kobayashi, Yosuke; Yoshida, Junjiro; Iwata, Hisashi; Koyama, Yoshiyuki; Kato, Jun; Ogihara, Jun; Kasumi, Takafumi

    2013-06-01

    Among three erythritol reductase isogenes (er1, er2, and er3) in Trichosporonoides megachiliensis SN-124A, er1 and er2 each had one stress response element (STRE) approximately 2 kbp upstream of their respective initiator codon; in contrast, er3 had two STREs, 148 and 40 bp upstream from the initiator codon. Based on intracellular erythritol accumulation and gene expression profiles, er3 seemed to be highly responsive to stress than er1 or er2. Under hyper-osmotic conditions, intracellular glycerol production, increased significantly within 1.5 h together with glycerol-3-phosphate dehydrogenase gene (gpd1) expression; in contrast, neither er gene expression nor the corresponding production of intracellular erythritol increased significantly within the first 1.5 h of hyper-osmotic culture. However, within 24 h of hyper-osmotic culture, erythritol production and er3 gene expression increased significantly and in parallel. Thus, we concluded that, as an initial response to hyper-osmotic growth conditions, T. megachiliensis produces glycerol as an osmoregulatory compatible solute via GPD; however, within 24 h, it begins to produce erythritol, mainly via ER3, as the preferred compatible solute. Heterologous expression of ers in a Saccharomyces cerevisiae mutant indicated that any of three ers might not function in S. cerevisiae for erythritol biosynthesis in spite of ers and corresponding ERs expression. Hence, although er is annotated as a galactose-inducible crystalline-like yeast protein gene (gcy1) homolog, er may be functionally different from gcy1 in glycolytic metabolism. Otherwise, S. cerevisiae is not likely to produce erythrose, the substrate of erythrose reductase due to metabolic characteristics. PMID:23294575

  14. Improved Stress Reliability of Analog TiHfO Metal-Insulator-Metal Capacitors Using High-Work-Function Electrode

    NASA Astrophysics Data System (ADS)

    Cheng, Chun-Hu; Chiang, Kuo-Cheng; Pan, Han-Chang; Hsiao, Chien-Nan; Chou, Chang-Pin; McAlister, Sean P.; Chin, Albert

    2007-11-01

    We have studied the reliability of high-κ (κ ˜ 49) TixHf1-xO (x ˜ 0.67) metal-insulator-metal (MIM) capacitors after constant voltage stress induction. The use of a high-work-function Ni top electrode improves not only the leakage current, and temperature- and voltage-coefficients of capacitance, but also the long-term capacitance variation after stress induction.

  15. Effect of fluoxetine and resveratrol on testicular functions and oxidative stress in a rat model of chronic mild stress-induced depression.

    PubMed

    Sakr, H F; Abbas, A M; Elsamanoudy, A Z; Ghoneim, F M

    2015-08-01

    Our objective was to investigate the effects of chronic unpredictable mild stress (CUMS) with or without selective serotonin reuptake inhibitor (fluoxetine) and anti-oxidant (resveratrol) on testicular functions and oxidative stress in rats. Fifty male rats were divided into 2 groups; control and CUMS. CUMS group was further subdivided into 4 subgroups administered water, fluoxetine, resveratrol and both. Sucrose intake, body weight gain, serum corticosterone, serotonin and testosterone levels, sperm count and motility, testicular malondialdehyde, superoxide dismutase (SOD), catalase, glutathione (GSH), and gene expression of steroidogenic acute-regulatory (StAR) protein and cytochrome P450 side chain cleavage (P450scc) enzyme were evaluated. CUMS decreased sucrose intake, weight gain, anti-oxidants (SOD, catalase, GSH), testosterone, serotonin, StAR and cytochrome P450scc gene expression, sperm count and motility and increased malondialdehyde and corticosterone. Fluoxetine increased malondialdehyde, sucrose intake, weight gain, serotonin and decreased anti-oxidants, StAR and cytochrome P450scc gene expression, sperm count and motility, testosterone, corticosterone in stressed rats. Administration of resveratrol increased anti-oxidants, sucrose intake, weight gain, serotonin, StAR and cytochrome P450scc gene expression, testosterone, sperm count and motility, and decreased malondialdehyde and corticosterone in stressed rats with or without fluoxetine. In conclusion, CUMS induces testicular dysfunctions and oxidative stress. While treatment of CUMS rats with fluoxetine decreases the depressive behavior, it causes further worsening of testicular dysfunctions and oxidative stress. Administration of resveratrol improves testicular dysfunctions and oxidative stress that are caused by CUMS and further worsened by fluoxetine treatment. PMID:26348076

  16. The impact of threat of shock on the framing effect and temporal discounting: executive functions unperturbed by acute stress?

    PubMed Central

    Robinson, Oliver J.; Bond, Rebecca L.; Roiser, Jonathan P.

    2015-01-01

    Anxiety and stress-related disorders constitute a large global health burden, but are still poorly understood. Prior work has demonstrated clear impacts of stress upon basic cognitive function: biasing attention toward unexpected and potentially threatening information and instantiating a negative affective bias. However, the impact that these changes have on higher-order, executive, decision-making processes is unclear. In this study, we examined the impact of a translational within-subjects stress induction (threat of unpredictable shock) on two well-established executive decision-making biases: the framing effect (N = 83), and temporal discounting (N = 36). In both studies, we demonstrate (a) clear subjective effects of stress, and (b) clear executive decision-making biases but (c) no impact of stress on these decision-making biases. Indeed, Bayes factor analyses confirmed substantial preference for decision-making models that did not include stress. We posit that while stress may induce subjective mood change and alter low-level perceptual and action processes (Robinson et al., 2013c), some higher-level executive processes remain unperturbed by these impacts. As such, although stress can induce a transient affective biases and altered mood, these need not result in poor financial decision-making. PMID:26441705

  17. Understanding the atomic-level Green-Kubo stress correlation function for a liquid through phonons in a model crystal

    NASA Astrophysics Data System (ADS)

    Levashov, V. A.

    2014-11-01

    In order to gain insight into the connection between the vibrational dynamics and the atomic-level Green-Kubo stress correlation function in liquids, we consider this connection in a model crystal instead. Of course, vibrational dynamics in liquids and crystals are quite different and it is not expected that the results obtained on a model crystal should be valid for liquids. However, these considerations provide a benchmark to which the results of the previous molecular dynamics simulations can be compared. Thus, assuming that vibrations are plane waves, we derive analytical expressions for the atomic-level stress correlation functions in the classical limit and analyze them. These results provide, in particular, a recipe for analysis of the atomic-level stress correlation functions in Fourier space and extraction of the wave-vector and frequency-dependent information. We also evaluate the energies of the atomic-level stresses. The energies obtained are significantly smaller than the energies previously determined in molecular dynamics simulations of several model liquids. This result suggests that the average energies of the atomic-level stresses in liquids and glasses are largely determined by the structural disorder. We discuss this result in the context of equipartition of the atomic-level stress energies. Analysis of the previously published data suggests that it is possible to speak about configurational and vibrational contributions to the average energies of the atomic-level stresses in a glass state. However, this separation in a liquid state is problematic. We also introduce and briefly consider the atomic-level transverse current correlation function. Finally, we address the broadening of the peaks in the pair distribution function with increase of distance. We find that the peaks' broadening (by ≈40 % ) occurs due to the transverse vibrational modes, while contribution from the longitudinal modes does not change with distance.

  18. Early life stress elicits visceral hyperalgesia and functional reorganization of pain circuits in adult rats

    PubMed Central

    Holschneider, D.P.; Guo, Y.; Mayer, E.A.; Wang, Z.

    2015-01-01

    Early life stress (ELS) is a risk factor for developing functional gastrointestinal disorders, and has been proposed to be related to a central amplification of sensory input and resultant visceral hyperalgesia. We sought to characterize ELS-related changes in functional brain responses during acute noxious visceral stimulation. Neonatal rats (males/females) were exposed to limited bedding (ELS) or standard bedding (controls) on postnatal days 2–9. Age 10–11 weeks, animals were implanted with venous cannulas and transmitters for abdominal electromyography (EMG). Cerebral blood flow (rCBF) was mapped during colorectal distension (CRD) using [14C]-iodoantipyrine autoradiography, and analyzed in three-dimensionally reconstructed brains by statistical parametric mapping and functional connectivity. EMG responses to CRD were increased after ELS, with no evidence of a sex difference. ELS rats compared to controls showed a greater significant positive correlation of EMG with amygdalar rCBF. Factorial analysis revealed a significant main effect of ‘ELS’ on functional activation of nodes within the pain pathway (somatosensory, insular, cingulate and prefrontal cortices, locus coeruleus/lateral parabrachial n. [LC/LPB], periaqueductal gray, sensory thalamus), as well as in the amygdala, hippocampus and hypothalamus. In addition, ELS resulted in an increase in the number of significant functional connections (i.e. degree centrality) between regions within the pain circuit, including the amygdala, LC/LPB, insula, anterior ventral cingulate, posterior cingulate (retrosplenium), and stria terminalis, with decreases noted in the sensory thalamus and the hippocampus. Sex differences in rCBF were less broadly expressed, with significant differences noted at the level of the cortex, amygdala, dorsal hippocampus, raphe, sensory thalamus, and caudate-putamen. ELS showed a sexually dimorphic effect (‘Sex x ELS’ interaction) at the LC/LPB complex, globus pallidus

  19. Mitochondrial oxidative stress in aortic stiffening with age: the role of smooth muscle cell function.

    EPA Science Inventory

    OBJECTIVE: Age-related aortic stiffness is an independent risk factor for cardiovascular diseases. Although oxidative stress is implicated in aortic stiffness, the underlying molecular mechanisms remain unelucidated. Here, we examined the source of oxidative stress in aging and i...

  20. Peroxisomal monodehydroascorbate reductase. Genomic clone characterization and functional analysis under environmental stress conditions.

    PubMed

    Leterrier, Marina; Corpas, Francisco J; Barroso, Juan B; Sandalio, Luisa M; del Río, Luis A

    2005-08-01

    In plant cells, ascorbate is a major antioxidant that is involved in the ascorbate-glutathione cycle. Monodehydroascorbate reductase (MDAR) is the enzymatic component of this cycle involved in the regeneration of reduced ascorbate. The identification of the intron-exon organization and the promoter region of the pea (Pisum sativum) MDAR 1 gene was achieved in pea leaves using the method of walking polymerase chain reaction on genomic DNA. The nuclear gene of MDAR 1 comprises nine exons and eight introns, giving a total length of 3,770 bp. The sequence of 544 bp upstream of the initiation codon, which contains the promoter and 5' untranslated region, and 190 bp downstream of the stop codon were also determined. The presence of different regulatory motifs in the promoter region of the gene might indicate distinct responses to various conditions. The expression analysis in different plant organs by northern blots showed that fruits had the highest level of MDAR. Confocal laser scanning microscopy analysis of pea leaves transformed with Agrobacterium tumefaciens having the binary vectors pGD, which contain the autofluorescent proteins enhanced green fluorescent protein and enhanced yellow fluorescent protein with the full-length cDNA for MDAR 1 and catalase, indicated that the MDAR 1 encoded the peroxisomal isoform. The functional analysis of MDAR by activity and protein expression was studied in pea plants grown under eight stress conditions, including continuous light, high light intensity, continuous dark, mechanical wounding, low and high temperature, cadmium, and the herbicide 2,4-dichlorophenoxyacetic acid. This functional analysis is representative of all the MDAR isoforms present in the different cell compartments. Results obtained showed a significant induction by high light intensity and cadmium. On the other hand, expression studies, performed by semiquantitative reverse transcription-polymerase chain reaction demonstrated differential expression patterns of

  1. Peroxisomal Monodehydroascorbate Reductase. Genomic Clone Characterization and Functional Analysis under Environmental Stress Conditions1

    PubMed Central

    Leterrier, Marina; Corpas, Francisco J.; Barroso, Juan B.; Sandalio, Luisa M.; del Río, Luis A.

    2005-01-01

    In plant cells, ascorbate is a major antioxidant that is involved in the ascorbate-glutathione cycle. Monodehydroascorbate reductase (MDAR) is the enzymatic component of this cycle involved in the regeneration of reduced ascorbate. The identification of the intron-exon organization and the promoter region of the pea (Pisum sativum) MDAR 1 gene was achieved in pea leaves using the method of walking polymerase chain reaction on genomic DNA. The nuclear gene of MDAR 1 comprises nine exons and eight introns, giving a total length of 3,770 bp. The sequence of 544 bp upstream of the initiation codon, which contains the promoter and 5′ untranslated region, and 190 bp downstream of the stop codon were also determined. The presence of different regulatory motifs in the promoter region of the gene might indicate distinct responses to various conditions. The expression analysis in different plant organs by northern blots showed that fruits had the highest level of MDAR. Confocal laser scanning microscopy analysis of pea leaves transformed with Agrobacterium tumefaciens having the binary vectors pGD, which contain the autofluorescent proteins enhanced green fluorescent protein and enhanced yellow fluorescent protein with the full-length cDNA for MDAR 1 and catalase, indicated that the MDAR 1 encoded the peroxisomal isoform. The functional analysis of MDAR by activity and protein expression was studied in pea plants grown under eight stress conditions, including continuous light, high light intensity, continuous dark, mechanical wounding, low and high temperature, cadmium, and the herbicide 2,4-dichlorophenoxyacetic acid. This functional analysis is representative of all the MDAR isoforms present in the different cell compartments. Results obtained showed a significant induction by high light intensity and cadmium. On the other hand, expression studies, performed by semiquantitative reverse transcription-polymerase chain reaction demonstrated differential expression patterns

  2. Podocyte-Specific Deletion of Murine CXADR Does Not Impair Podocyte Development, Function or Stress Response.

    PubMed

    Schell, Christoph; Kretz, Oliver; Bregenzer, Andreas; Rogg, Manuel; Helmstädter, Martin; Lisewski, Ulrike; Gotthardt, Michael; Tharaux, Pierre-Louis; Huber, Tobias B; Grahammer, Florian

    2015-01-01

    The coxsackie- and adenovirus receptor (CXADR) is a member of the immunoglobulin protein superfamily, present in various epithelial cells including glomerular epithelial cells. Beside its known function as a virus receptor, it also constitutes an integral part of cell-junctions. Previous studies in the zebrafish pronephros postulated a potential role of CXADR for the terminal differentiation of glomerular podocytes and correct patterning of the elaborated foot process architecture. However, due to early embryonic lethality of constitutive Cxadr knockout mice, mammalian data on kidney epithelial cells have been lacking. Interestingly, Cxadr is robustly expressed during podocyte development and in adulthood in response to glomerular injury. We therefore used a conditional transgenic approach to elucidate the function of Cxadr for podocyte development and stress response. Surprisingly, we could not discern a developmental phenotype in podocyte specific Cxadr knock-out mice. In addition, despite a significant up regulation of CXADR during toxic, genetic and immunologic podocyte injury, we could not detect any impact of Cxadr on these injury models. Thus these data indicate that in contrast to lower vertebrate models, mammalian podocytes have acquired molecular programs to compensate for the loss of Cxadr. PMID:26076477

  3. Parahippocampal activation evoked by masked traumatic images in posttraumatic stress disorder: a functional MRI study.

    PubMed

    Sakamoto, Hideshi; Fukuda, Rin; Okuaki, Tomoyuki; Rogers, Mark; Kasai, Kiyoto; Machida, Toru; Shirouzu, Ichiro; Yamasue, Hidenori; Akiyama, Tsuyoshi; Kato, Nobumasa

    2005-07-01

    Posttraumatic stress disorder (PTSD) has been widely studied, but its neural mechanism is still unclear. The purpose of this study is to identify dysfunctional areas in PTSD throughout the whole brain to help to elucidate the neural mechanisms of PTSD. Sixteen patients with PTSD and sixteen healthy controls participated in this study. Traumatic images under perceptual threshold including scenes of earthquakes, traffic accidents, ambulances, emergency rooms, and crimes were presented to the participants, and brain activation was measured using functional MRI. Functional brain images of both groups were evaluated with random effect analysis for the whole brain. In the control group, activation in the ventral frontoparietal areas correlated significantly with presentation of the masked traumatic stimuli. In the PTSD group, activation was not observed in these areas, but significant activation correlated with the masked traumatic stimuli in the parahippocampal region including the left parahippocampal gyrus and tail of the left hippocampus. These results suggest that in PTSD patients activation in the ventral frontoparietal network associated with visual attention processing is attenuated, while the left hippocampal area associated with episodic and autobiographical memory is abnormally easily activated. This pattern of activation corresponds well to the clinical characteristics of PTSD, in which even slight traumatic stimuli tend to induce intrusive recollection or flashbacks, despite a general decrease in attention and ability to concentrate. PMID:15955491

  4. Understanding the potency of stressful early life experiences on brain and body function.

    PubMed

    McEwen, Bruce S

    2008-10-01

    Early life experiences have powerful effects on the brain and body lasting throughout the entire life span and influencing brain function, behavior, and the risk for a number of systemic and mental disorders. Animal models of early life adversity are providing mechanistic insights, including glimpses into the fascinating world that is now called "epigenetics" as well as the role of naturally occurring alleles of a number of genes. These studies also provide insights into the adaptive value as well as the negative consequences, of early life stress, exposure to novelty, and poor-quality vs good-quality maternal care. Animal models begin to provide a mechanistic basis for understanding how brain development and physiological functioning is affected in children exposed to early life abuse and neglect, where there is a burgeoning literature on the consequences for physical health and emotional and cognitive development. An important goal is to identify interventions that are likely to be most effective in early life and some guidelines are provided. PMID:18803958

  5. Functional Neuroimaging of Emotionally Intense Autobiographical Memories in Post-Traumatic Stress Disorder

    PubMed Central

    St. Jacques, Peggy L.; Botzung, Anne; Miles, Amanda; Rubin, David C.

    2010-01-01

    Post-traumatic stress disorder (PTSD) affects regions that support autobiographical memory (AM) retrieval, such as the hippocampus, amygdala and ventral medial prefrontal cortex (PFC). However, it is not well understood how PTSD may impact the neural mechanisms of memory retrieval for the personal past. We used a generic cue method combined with parametric modulation analysis and functional MRI (fMRI) to investigate the neural mechanisms affected by PTSD symptoms during the retrieval of a large sample of emotionally intense AMs. There were three main results. First, the PTSD group showed greater recruitment of the amygdala/hippocampus during the construction of negative versus positive emotionally intense AMs, when compared to controls. Second, across both the construction and elaboration phases of retrieval the PTSD group showed greater recruitment of the ventral medial PFC for negatively intense memories, but less recruitment for positively intense memories. Third, the PTSD group showed greater functional coupling between the ventral medial PFC and the amygdala for negatively intense memories, but less coupling for positively intense memories. In sum, the fMRI data suggest that there was greater recruitment and coupling of emotional brain regions during the retrieval of negatively intense AMs in the PTSD group when compared to controls. PMID:21109253

  6. How emotional abilities modulate the influence of early life stress on hippocampal functioning.

    PubMed

    Aust, Sabine; Alkan Härtwig, Elif; Koelsch, Stefan; Heekeren, Hauke R; Heuser, Isabella; Bajbouj, Malek

    2014-07-01

    Early life stress (ELS) is known to have considerable influence on brain development, mental health and affective functioning. Previous investigations have shown that alexithymia, a prevalent personality trait associated with difficulties experiencing and verbalizing emotions, is particularly related to ELS. The aim of the present study was to investigate how neural correlates of emotional experiences in alexithymia are altered in the presence and absence of ELS. Therefore, 50 healthy individuals with different levels of alexithymia were matched regarding ELS and investigated with respect to neural correlates of audio-visually induced emotional experiences via functional magnetic resonance imaging. The main finding was that ELS modulated hippocampal responses to pleasant (>neutral) stimuli in high-alexithymic individuals, whereas there was no such modulation in low-alexithymic individuals matched for ELS. Behavioral and psychophysiological results followed a similar pattern. When considered independent of ELS, alexithymia was associated with decreased responses in insula (pleasant > neutral) and temporal pole (unpleasant > neutral). Our results show that the influence of ELS on emotional brain responses seems to be modulated by an individual's degree of alexithymia. Potentially, protective and adverse effects of emotional abilities on brain responses to emotional experiences are discussed. PMID:23685776

  7. Understanding the potency of stressful early life experiences on brain and body function

    PubMed Central

    McEwen, Bruce S.

    2008-01-01

    Early life experiences have powerful effects on the brain and body lasting throughout the entire lifespan and influencing brain function, behavior and the risk for a number of systemic and mental disorders. Animal models of early life adversity are providing mechanistic insights, including glimpses into the fascinating world that is now called “epigenetics” as well as the role of naturally occurring alleles of a number of genes. These studies also provide insights into the adaptive value, as well as the negative consequences, of early life stress, exposure to novelty, and poor vs good quality maternal care. Animal models begin to provide a mechanistic basis for understanding how brain development and physiological functioning is affected in children exposed to early life abuse and neglect, where there is a burgeoning literature on the consequences for physical health and emotional and cognitive development. An important goal is to identify interventions that are likely to be most effective in early life and some guidelines are provided. PMID:18803958

  8. Podocyte-Specific Deletion of Murine CXADR Does Not Impair Podocyte Development, Function or Stress Response

    PubMed Central

    Schell, Christoph; Kretz, Oliver; Bregenzer, Andreas; Rogg, Manuel; Helmstädter, Martin; Lisewski, Ulrike; Gotthardt, Michael; Tharaux, Pierre-Louis; Huber, Tobias B.; Grahammer, Florian

    2015-01-01

    The coxsackie- and adenovirus receptor (CXADR) is a member of the immunoglobulin protein superfamily, present in various epithelial cells including glomerular epithelial cells. Beside its known function as a virus receptor, it also constitutes an integral part of cell-junctions. Previous studies in the zebrafish pronephros postulated a potential role of CXADR for the terminal differentiation of glomerular podocytes and correct patterning of the elaborated foot process architecture. However, due to early embryonic lethality of constitutive Cxadr knockout mice, mammalian data on kidney epithelial cells have been lacking. Interestingly, Cxadr is robustly expressed during podocyte development and in adulthood in response to glomerular injury. We therefore used a conditional transgenic approach to elucidate the function of Cxadr for podocyte development and stress response. Surprisingly, we could not discern a developmental phenotype in podocyte specific Cxadr knock-out mice. In addition, despite a significant up regulation of CXADR during toxic, genetic and immunologic podocyte injury, we could not detect any impact of Cxadr on these injury models. Thus these data indicate that in contrast to lower vertebrate models, mammalian podocytes have acquired molecular programs to compensate for the loss of Cxadr. PMID:26076477

  9. Yeast functional screen to identify genes conferring salt stress tolerance in Salicornia europaea

    PubMed Central

    Nakahara, Yoshiki; Sawabe, Shogo; Kainuma, Kenta; Katsuhara, Maki; Shibasaka, Mineo; Suzuki, Masanori; Yamamoto, Kosuke; Oguri, Suguru; Sakamoto, Hikaru

    2015-01-01

    Salinity is a critical environmental factor that adversely affects crop productivity. Halophytes have evolved various mechanisms to adapt to saline environments. Salicornia europaea L. is one of the most salt-tolerant plant species. It does not have special salt-secreting structures like a salt gland or salt bladder, and is therefore a good model for studying the common mechanisms underlying plant salt tolerance. To identify candidate genes encoding key proteins in the mediation of salt tolerance in S. europaea, we performed a functional screen of a cDNA library in yeast. The library was screened for genes that allowed the yeast to grow in the presence of 1.3 M NaCl. We obtained three full-length S. europaea genes that confer salt tolerance. The genes are predicted to encode (1) a novel protein highly homologous to thaumatin-like proteins, (2) a novel coiled-coil protein of unknown function, and (3) a novel short peptide of 32 residues. Exogenous application of a synthetic peptide corresponding to the 32 residues improved salt tolerance of Arabidopsis. The approach described in this report provides a rapid assay system for large-scale screening of S. europaea genes involved in salt stress tolerance and supports the identification of genes responsible for such mechanisms. These genes may be useful candidates for improving crop salt tolerance by genetic transformation. PMID:26579166

  10. Assessing Stress Reduction as a Function of Artistic Creation and Cognitive Focus

    ERIC Educational Resources Information Center

    Curl, Krista

    2008-01-01

    In this outcomes study (N=40), changes in stress levels were compared across two participant conditions for a period of artistic activity with a cognitive focus on either a personally stressful or positive situation. Results indicated that participants in the positive-focus condition demonstrated a significant decrease in stress, whereas…

  11. Perfusion functional MRI reveals cerebral blood flow pattern under psychological stress

    PubMed Central

    Wang, Jiongjiong; Rao, Hengyi; Wetmore, Gabriel S.; Furlan, Patricia M.; Korczykowski, Marc; Dinges, David F.; Detre, John A.

    2005-01-01

    Despite the prevalence of stress in everyday life and its impact on happiness, health, and cognition, little is known about the neural substrate of the experience of everyday stress in humans. We use a quantitative and noninvasive neuroimaging technique, arterial spin-labeling perfusion MRI, to measure cerebral blood flow (CBF) changes associated with mild to moderate stress induced by a mental arithmetic task with performance monitoring. Elicitation of stress was verified by self-report of stress and emotional state and measures of heart rate and salivary-cortisol level. The change in CBF induced by the stress task was positively correlated with subjective stress rating in the ventral right prefrontal cortex (RPFC) and left insula/putamen area. The ventral RPFC along with right insula/putamen and anterior cingulate showed sustained activation after task completion in subjects reporting a high stress level during arithmetic tasks. Additionally, variations of baseline CBF in the ventral RPFC and right orbitofrontal cortex were found to correlate with changes in salivary-cortisol level and heart rate caused by undergoing stress tasks. We further demonstrated that the observed right prefrontal activation could not be attributed to increased cognitive demand accompanying stress tasks and extended beyond neural pathways associated with negative emotions. Our results provide neuroimaging evidence that psychological stress induces negative emotion and vigilance and that the ventral RPFC plays a key role in the central stress response. PMID:16306271

  12. Perfusion functional MRI reveals cerebral blood flow pattern under psychological stress

    NASA Astrophysics Data System (ADS)

    Wang, Jiongjiong; Rao, Hengyi; Wetmore, Gabriel S.; Furlan, Patricia M.; Korczykowski, Marc; Dinges, David F.; Detre, John A.

    2005-12-01

    Despite the prevalence of stress in everyday life and its impact on happiness, health, and cognition, little is known about the neural substrate of the experience of everyday stress in humans. We use a quantitative and noninvasive neuroimaging technique, arterial spin-labeling perfusion MRI, to measure cerebral blood flow (CBF) changes associated with mild to moderate stress induced by a mental arithmetic task with performance monitoring. Elicitation of stress was verified by self-report of stress and emotional state and measures of heart rate and salivary-cortisol level. The change in CBF induced by the stress task was positively correlated with subjective stress rating in the ventral right prefrontal cortex (RPFC) and left insula/putamen area. The ventral RPFC along with right insula/putamen and anterior cingulate showed sustained activation after task completion in subjects reporting a high stress level during arithmetic tasks. Additionally, variations of baseline CBF in the ventral RPFC and right orbitofrontal cortex were found to correlate with changes in salivary-cortisol level and heart rate caused by undergoing stress tasks. We further demonstrated that the observed right prefrontal activation could not be attributed to increased cognitive demand accompanying stress tasks and extended beyond neural pathways associated with negative emotions. Our results provide neuroimaging evidence that psychological stress induces negative emotion and vigilance and that the ventral RPFC plays a key role in the central stress response. anterior cingulate cortex | arterial spin labeling | right prefrontal cortex

  13. Isolation of high salinity stress tolerant genes from Pisum sativum by random overexpression in Escherichia coli and their functional validation.

    PubMed

    Joshi, Amita; Dang, Hung Quang; Vaid, Neha; Tuteja, Narendra

    2009-05-01

    Salinity stress is one of the major factors which reduce crop plants growth and productivity resulting in significant economic losses worldwide. Therefore, it would be fruitful to isolate and functionally identify new salinity stress-induced genes for understanding the mechanism and developing salinity stress tolerant plants. Based on functional gene screening assay, we have isolated few salinity tolerant genes out of one million Escherichia coli (SOLR) transformants containing pea cDNAs. Sequence analysis of three of these genes revealed homology to Ribosomal-L30E (RPL30E), Chlorophyll-a/b-binding protein (Chla/bBP) and FIDDLEHEAD (FDH). The salinity tolerance of these genes in bacteria was further confirmed by using another strain of E. coli (DH5alpha) transformants. The homology based computational modeling of these proteins suggested the high degree of conservation with the conserved domains of their homologous partners. The reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed that the expression of these cDNAs (except the FDH) was upregulated in pea plants in response to NaCl stress. We observed that there was no significant effect of Li(+) ion on the expression level of these genes, while an increase in response to K(+) ion was observed. Overall, this study provides an evidence for a novel function of these genes in high salinity stress tolerance. The PsFDH showed constitutive expression in planta suggesting that it can be used as constitutively expressed marker gene for salinity stress tolerance in plants. This study brings new direction in identifying novel function of unidentified genes in abiotic stress tolerance without previous knowledge of the genome sequence. PMID:19816097

  14. Acute brief heat stress in late gestation alters neonatal calf innate immune functions.

    PubMed

    Strong, R A; Silva, E B; Cheng, H W; Eicher, S D

    2015-11-01

    Heat stress, as one of the environmental stressors affecting the dairy industry, compromises the cow milk production, immune function, and reproductive system. However, few studies have looked at how prenatal heat stress (HS) affects the offspring. The objective of this study was to evaluate the effect of HS during late gestation on calf immunity. Calves were born to cows exposed to evaporative cooling (CT) or HS (cyclic 23-35°C) for 1 wk at 3 wk before calving. Both bull and heifer calves (CT, n=10; HS, n=10) were housed in similar environmental temperatures after birth. Both CT and HS calves received 3.78 L of pooled colostrum within 12 h after birth and were fed the same diet throughout the study. In addition to tumor necrosis factor α, IL-1β, IL-1 receptor antagonist (IL-1RA), and toll-like receptor (TLR)2, and TLR4 mRNA expression, the expression of CD14(+) and CD18(+) cells, and DEC205(+) dendritic cells were determined in whole blood samples at d 0, 3, 7, 14, 21, and 28. The neutrophil to lymphocyte ratio, differential cell counts, and the hematocrit were also determined. During late gestation, the HS cows had greater respiration rates, rectal temperatures, and tended to spend more time standing compared with the CT cows. The HS calves had less expression of tumor necrosis factor-α and TLR2 and greater levels of IL-1β, IL-1RA, and TLR4 compared with CT calves. The HS calves also had a greater percentage of CD18(+) cells compared with the CT calves. Additionally, a greater percentage of neutrophils and lesser percentage of lymphocytes were in the HS calves compared with the CT calves. The results indicate that biomarkers of calves' immunity are affected in the first several weeks after birth by HS in the dam during late gestation. PMID:26298746

  15. Functional conservation analysis and expression modes of grape anthocyanin synthesis genes responsive to low temperature stress.

    PubMed

    Zhang, Cheng; Jia, Haifeng; Wu, Weimin; Wang, Xicheng; Fang, Jinggui; Wang, Chen

    2015-12-10

    In grape cultivation, low temperature generally increases the expression of genes involved in synthesis of anthocyanin. In this study, multi-type structural analysis of the proteins encoded by five anthocyanin biosynthesis genes VvF3H, VvPAL, VvCHS3, VvCHS2 and VvLDOX, in addition to nine of their homologous genes revealed that proteins in grapevine shared a high similarity with that in kiwi, red orange and some other species in which the biosynthesis of anthocyanin significantly influenced by low temperature as proved by previous studies. Low temperature regulatory elements were also found in the promoter region of the grapevine genes VvCHS2, VvPAL and VvF3H. These findings indicate that the functions of anthocyanin biosynthesis genes in grapevine are conservative and might be sensitive to low temperature. In order to identify the specific expression patterns of the five anthocyanin biosynthesis genes and the changes of polyphenols, anthocyanins and flavonoids under low temperature stress. The transcription analysis of the five genes and the content of polyphenols, anthocyanins and flavonoids in grape skins were examined, by using Vitis vinifera L. cv. 'Yongyou 1' and 'Juxing' berries as experimental material and treated at 4°C and 25°C for 24h, 48 h, 72 h and 96 h. The results showed that low temperature greatly enhanced the expression of the five anthocyanin biosynthesis genes. Low temperature greatly slowed down the decomposition of polyphenol, anthocyanin, and flavonoid in grape skins. Our study also found that cv. 'Juxing' responded more sensitively to low temperature than cv. 'Yongyou 1'. All the findings would provide a basis for further study on the mechanism of anthocyanin biosynthesis under environmental stress. PMID:26253159

  16. Stress Response in Rhodopseudomonas palustris CGA010 is Mediated by an Extracytoplasmic Function Sigma Factor

    DOE PAGESBeta

    Allen, Michael S; Hurst, Gregory; Lu, Tse-Yuan S; Leslie, Perry M; Pan, Chongle; Lankford, Patricia K; Pelletier, Dale A

    2015-01-01

    Abstract Little is known about the roles of the 16 extracytoplasmic function (ECF) sigma factors in Rhodopseudomonas palustris gene regulation. To begin to address this deficiency, the whole proteome of R. palustris CGA010 was analyzed by tandem mass spectrometry from cultures episomally expressing the ECF RPA4225. Among the proteins with the greatest increase in abundance were the catalase KatE, trehalose synthase, a DPS-like protein, and several regulatory proteins. Alignment of the cognate promoter regions driving expression of several up-regulated proteins revealed a conserved binding motif in the -35 and -10 regions with the consensus sequence GGAAC-18N-TT. Analysis of the genomemore » revealed the occurrence of this motif in the promoters of over 150 genes, including general stress proteins, ATP-dependent DNA ligase, two Ku-domain-containing proteins, and the heat-shock m factor rpoH. Additionally, the putative anti- m factor RPA4224, whose gene is contained in the same predicted operon as RPA4225, was identified as interacting directly with the predicted response regulator RPA4223 by mass spectrometry of affinity isolated protein complexes. Furthermore, another protein containing a cytoplasmic histidine kinase domain is located immediately upstream of RPA4225. The genomic organization of homologues for these four genes is conserved in several other strains of R. palustris as well as in closely related \\-proteobacteria. Taken together, these data suggest that ECF RPA4225 controls a global stress regulon that is in turn controlled via a phosphorelay mechanism involving a histidine kinase sensor, a response regulator, and an anti m factor that are conserved among several members of \\-proteobacteria.« less

  17. Heat stress modifies human baroreflex function independently of heat-induced hypovolemia.

    PubMed

    Kamiya, Atsunori; Michikami, Daisaku; Hayano, Junichiro; Sunagawa, Kenji

    2003-06-01

    Since human thermoregulatory heat loss responses, cutaneous vasodilation and sweating, cause hypovolemia, they should resultantly stimulate human baroreflexes. However, it is possible that the thermoregulatory system directly interacts with the baroreflex system through central neural connections independently of the heat-induced hypovolemia. We hypothesized that heat stress modifies the baroreflex control of sympathetic nerve activity independently of heat-induced hypovolemia in humans. We made whole-body heating with tube-lined suits perfused with warm water (46-47 degrees C) on 10 healthy male subjects. The heating increased skin and tympanic temperatures by 10.0 and 0.4 degrees C, respectively. It increased resting total muscle sympathetic nerve activity (MSNA, microneurography) by 94 +/- 9% and decreased central venous pressure (CVP, dependent arm technique) by 2.6 +/- 0.9 mmHg. The heating increased arterial baroreflex gain by 193%, assessed as a response of MSNA to a decrease in diastolic arterial pressure during Valsalva's maneuver, but it did not change threshold arterial pressure for MSNA activation. Although the heating did not change the cardiopulmonary baroreflex gain assessed as a response of MSNA to a change in estimated central venous pressure (CVP) during a 10 degrees head-down and -up tilt test, it upwardly shifted the stimulus-response baroreflex relationship. These changes in baroreflex functions during heating were not restored by an intravenous infusion of warmed isotonic saline (37 degrees C, 15 ml/kg) that restored the heat-induced reduction of CVP. Our results support our hypothesis that heat stress modifies the baroreflex control of MSNA independently of heat-induced hypovolemia in humans. Our results also suggest that the hyperthermal modification of baroreflex results from central neural interaction between thermoregulatory and baroreflex systems. PMID:14529582

  18. Alterations of CNS structure & function by charged particle radiation & resultant oxidative stress

    NASA Astrophysics Data System (ADS)

    Nelson, Gregory; Chang, Polly; Favre, Cecile; Fike, John; Komarova, Natalia; Limoli, Charles; Mao, Xiao-Wen; Obenaus, Andre; Raber, Jacob; Spigelman, Igor; Soltesz, Ivan; Song, Sheng-Kwei; Stampanoni, Marco; Vlkolinsky, Roman; Wodarz, Dominik

    were complex and suggested continuous remodeling of the brain for up to 6 months. Thus we demonstrated a suite of CNS structural and functional changes after proton and iron ion exposure in the low dose regime. Based on these findings we will now test whether oxidative stress mediates the reactions of CNS to radiation exposure and what role radiation quality and dose rate play in the responses. We will use cultured neural precursor cells (mouse human) to detect changes in oxidative status and differentiation as functions of charged particle charge and velocity. These results will inform the selection of particles for many in vivo measurements that will compare wild type mice to a transgenic strain that over-expresses a human catalase gene (which inactivates hydrogen peroxide) in the mitochondrial compartment. This will explicitly test the role of reactive oxygen species in mediating the mechanisms underlying the CNS endpoints that we will measure. We will extend the electrophysiological measurements on individual nerves in hippocampal slices to characterize both inhibitory and excitatory synapses. Further, multi-electrode arrays will be used to follow correlated electrical activity in different hippocampal regions in order to understand network-level function as well as synaptic efficacy and plasticity. Controlled oxidative stress on irradiated samples will explore whether response mechanisms are shared. To link alterations in neurogenesis to performance we will explore behavioral changes mediated by the hippocampus simultaneously with measures of expression of the Arc gene in newly-born neurons. This will test whether decrements in performance correlate with loss of new cells and whether behavior properly stimulates functional integration of the new cells; the behavioral paradigm will be contextual fear conditioning. We will develop mathematical frameworks for CNS responses to radiation in order to inform risk estimates. Finally, we will couple a high

  19. Prenatal Stress Produces Persistence of Remote Memory and Disrupts Functional Connectivity in the Hippocampal-Prefrontal Cortex Axis.

    PubMed

    Negrón-Oyarzo, Ignacio; Neira, David; Espinosa, Nelson; Fuentealba, Pablo; Aboitiz, Francisco

    2015-09-01

    Prenatal stress is a risk factor for the development of neuropsychiatric disorders, many of which are commonly characterized by an increased persistence of aversive remote memory. Here, we addressed the effect of prenatal stress on both memory consolidation and functional connectivity in the hippocampal-prefrontal cortex axis, a dynamical interplay that is critical for mnemonic processing. Pregnant mice of the C57BL6 strain were subjected to restraint stressed during the last week of pregnancy, and male offspring were behaviorally tested at adulthood for recent and remote spatial memory performance in the Barnes Maze test under an aversive context. Prenatal stress did not affect the acquisition or recall of recent memory. In contrast, it produced the persistence of remote spatial memory. Memory persistence was not associated with alterations in major network rhythms, such as hippocampal sharp-wave ripples (SWRs) or neocortical spindles. Instead, it was associated with a large decrease in the basal discharge activity of identified principal neurons in the medial prefrontal cortex (mPFC) as measured in urethane anesthetized mice. Furthermore, functional connectivity was disrupted, as the temporal coupling between neuronal discharge in the mPFC and hippocampal SWRs was decreased by prenatal stress. These results could be relevant to understand the biological basis of the persistence of aversive remote memories in stress-related disorders. PMID:24860018

  20. Psychosocial Stress in Nurses With Shift Work Schedule Is Associated With Functional Gastrointestinal Disorders

    PubMed Central

    Koh, Seong-Joon; Kim, Mingoo; Oh, Da Yeon; Kim, Byeong Gwan; Lee, Kook Lae; Kim, Ji Won

    2014-01-01

    Background/Aims The aim of this study was to investigate the role of psychosocial problems and their associations with rotating shift work in the development of functional gastrointestinal disorders. Methods In this cross-sectional observation study, survey was administered to nurses and nurse assistants in a referral hospital. In addition to demographic questions, subjects were asked to complete the Rome III Questionnaire, Pittsburgh Sleep Quality Index and Rome III Psychosocial Alarm Questionnaire. Results Responses from 301 subjects were assessed. The overall prevalence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) were 15.0% and 19.6%, respectively. Psychosocial alarms were prevalent in the nursing personnel (74.8% with alarm presence and 23.3% with serious condition) and were more frequent among rotating shift workers (84.7% vs. 74.5% for alarm presence and 28.1% vs. 13.3% for serious condition). The prevalence of both IBS and FD significantly increased with psychosocial risk. An independent risk factor for IBS was serious psychosocial alarm (adjusted odds ratio [aOR], 10.75; 95% confidence interval (CI), 1.30–88.99; P = 0.028). Serious psychosocial alarm was an independent risk factor for FD (aOR, 7.84; 95% CI, 1.98–31.02; P = 0.003). Marriage (aOR 0.30; 95% CI, 0.09–0.93; P = 0.037) was associated with the decreased risk of FD. Conclusions The high prevalence of psychosocial stress among nurses who work rotating shifts is associated with the development of functional gastrointestinal disorders. PMID:25230903

  1. A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

    PubMed Central

    Scott, J. Cobb; Matt, Georg E.; Wrocklage, Kristen M.; Crnich, Cassandra; Jordan, Jessica; Southwick, Steven M.; Krystal, John H.; Schweinsburg, Brian C.

    2014-01-01

    Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect size estimates were calculated using a mixed-effects meta-analysis for nine cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d =−.62), speed of information processing (d =−.59), attention/working memory (d =−.50), and verbal memory (d =−.46). Effect size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature. PMID:25365762

  2. Viscosity and stress autocorrelation function in supercooled water: a molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Guo, Guang-Jun; Zhang, Yi-Gang; Refson, Keith; Zhao, Ya-Juan

    Following GUO, G.-J., and ZHANG, Y.-G., 2001, Molec. Phys. , 99 , 283, which calculates the bulk and shear viscosities of SPC/E water at 30°C and 0.999gcm -3 , further molecular dynamics simulations have been performed at state points of 0°C,-20°C,-40°C, and -60°C along an approximate isobar with the previous state point. SACF and BACF (stress autocorrelation functions related to shear and bulk viscosities, respectively) of high precision have been obtained and compared for their similarities and differences. Shear and bulk viscosities calculated from them showed an increased deviation from real water with decreasing temperature. These correlation functions were then fitted using a uniform two-step relaxation function including a fast oscillatory Kohlrausch law and a slow straightforward Kohlrausch law. The fitting parameters of SACF and BACF have been analysed in detail, and several interesting dynamic phenomena were observed. (1) The oscillation frequency of SACF (44 ~ 48ps -1 ) for short time intervals agrees with the stretching mode of hydrogen bonds, while that of BACF (7 ~ 12ps -1 ) agrees with the bending mode of hydrogen bonds. (2) With decreasing temperature, the slow relaxation fraction of the BACF increases, while that of the SACF remains constant. (3) The exponents βin the Kohlrausch laws with values greater than 1 are obtained for BACF at ambient temperatures. (4) With regard to both shear and bulk viscosities, the slow relaxation time largely increases with decreasing temperature, while the fast relaxation time slightly decreases. These phenomena are qualitatively explained and discussed.

  3. Elucidating dimensions of posttraumatic stress symptoms and their functional correlates in disaster-exposed adolescents.

    PubMed

    Sumner, Jennifer A; Pietrzak, Robert H; Danielson, Carla Kmett; Adams, Zachary W; Ruggiero, Kenneth J

    2014-12-01

    The aim of this study was to elucidate the dimensional structure of posttraumatic stress disorder (PTSD) and potential moderators and functional correlates of this structure in disaster-affected adolescents. A population-based sample of 2000 adolescents aged 12-17 years (M = 14.5 years; 51% female) completed interviews on post-tornado PTSD symptoms, substance use, and parent-adolescent conflict between 4 and 13 months (M = 8.8, SD = 2.6) after tornado exposure. Confirmatory factor analyses revealed that all models fit well but a 5-factor dysphoric arousal model provided a statistically significantly better representation of adolescent PTSD symptoms compared to 4-factor dysphoria and emotional numbing models. There was evidence of measurement invariance of the dysphoric arousal model across gender and age, although girls and older adolescents aged 15-17 years had higher mean scores than boys and younger adolescents aged 12-14 years, respectively, on some PTSD dimensions. Differential magnitudes of association between PTSD symptom dimensions and functional correlates were observed, with emotional numbing symptoms most strongly positively associated with problematic substance use since the tornado, and dysphoric arousal symptoms most strongly positively associated with parent-adolescent conflict; both correlations were significantly larger than the corresponding correlations with anxious arousal. Taken together, these results suggest that the dimensional structure of tornado-related PTSD symptomatology in adolescents is optimally characterized by five separate clusters of re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal symptoms, which showed unique associations with functional correlates. Findings emphasize that PTSD in disaster-exposed adolescents is not best conceptualized as a homogenous construct and highlight potential differential targets for post-disaster assessment and intervention. PMID:25248557

  4. Elucidating Dimensions of Posttraumatic Stress Symptoms and their Functional Correlates in Disaster-Exposed Adolescents

    PubMed Central

    Sumner, Jennifer A.; Pietrzak, Robert H.; Danielson, Carla Kmett; Adams, Zachary W.; Ruggiero, Kenneth J.

    2014-01-01

    The aim of this study was to elucidate the dimensional structure of posttraumatic stress disorder (PTSD) and potential moderators and functional correlates of this structure in disaster-affected adolescents. A population-based sample of 2,000 adolescents aged 12–17 years (M=14.5 years; 51% female) completed interviews on post-tornado PTSD symptoms, substance use, and parent-adolescent conflict between 4 and 13 months (M=8.8, SD=2.6) after tornado exposure. Confirmatory factor analyses revealed that all models fit well but a 5-factor dysphoric arousal model provided a statistically significantly better representation of adolescent PTSD symptoms compared to 4-factor dysphoria and emotional numbing models. There was evidence of measurement invariance of the dysphoric arousal model across gender and age, although girls and older adolescents aged 15–17 years had higher mean scores than boys and younger adolescents aged 12–14 years, respectively, on some PTSD dimensions. Differential magnitudes of association between PTSD symptom dimensions and functional correlates were observed, with emotional numbing symptoms most strongly positively associated with problematic substance use since the tornado, and dysphoric arousal symptoms most strongly positively associated with parent-adolescent conflict; both correlations were significantly larger than the corresponding correlations with anxious arousal. Taken together, these results suggest that the dimensional structure of tornado-related PTSD symptomatology in adolescents is optimally characterized by five separate clusters of re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal symptoms, which showed unique associations with functional correlates. Findings emphasize that PTSD in disaster-exposed adolescents is not best conceptualized as a homogeneous construct and highlight potential differential targets for post-disaster assessment and intervention. PMID:25248557

  5. Successive deep dives impair endothelial function and enhance oxidative stress in man.

    PubMed

    Obad, Ante; Marinovic, Jasna; Ljubkovic, Marko; Breskovic, Toni; Modun, Darko; Boban, Mladen; Dujic, Zeljko

    2010-11-01

    The aim of this study was to assess the effects of successive deep dives on endothelial function of large conduit arteries and plasma pro-oxidant and antioxidant activity. Seven experienced divers performed six dives in six consecutive days using a compressed mixture of oxygen, helium and nitrogen (trimix) with diving depths ranging from 55 to 80 m. Before and after first, third and sixth dive, venous gas emboli formation and brachial artery function (flow-mediated dilation, FMD) was assessed by ultrasound. In addition, plasma antioxidant capacity (AOC) was measured by ferric reducing antioxidant power, and the level of oxidative stress was assessed by thiobarbituric acid-reactive substances (TBARS) method. Although the FMD was reduced to a similar extent after each dive, the comparison of predive FMD showed a reduction from 8.6% recorded before the first dive to 6.3% before the third (P = 0.03) and 5.7% before the sixth dive (P = 0.003). A gradual shift in baseline was also detected with TBARS assay, with malondialdehyde values increasing from 0.10 ± 0.02 μmol l⁻¹ before the first dive to 0.16 ± 0.03 before the sixth (P = 0.005). Predive plasma AOC values also showed a decreasing trend from 0.67 ± 0.20 mmol l⁻¹ trolox equivalents (first day) to 0.56 ± 0.12 (sixth day), although statistical significance was not reached (P = 0.08). This is the first documentation of acute endothelial dysfunction in the large conduit arteries occurring after successive deep trimix dives. Both endothelial function and plasma pro-oxidant and antioxidant activity did not return to baseline during the course of repetitive dives, indicating possible cumulative and longer lasting detrimental effects. PMID:20718805

  6. Abnormal functional architecture of amygdala-centered networks in adolescent posttraumatic stress disorder.

    PubMed

    Aghajani, Moji; Veer, Ilya M; van Hoof, Marie-José; Rombouts, Serge A R B; van der Wee, Nic J; Vermeiren, Robert R J M

    2016-03-01

    Posttraumatic stress disorder (PTSD) is a prevalent, debilitating, and difficult to treat psychiatric disorder. Very little is known of how PTSD affects neuroplasticity in the developing adolescent brain. Whereas multiple lines of research implicate amygdala-centered network dysfunction in the pathophysiology of adult PTSD, no study has yet examined the functional architecture of amygdala subregional networks in adolescent PTSD. Using intrinsic functional connectivity analysis, we investigated functional connectivity of the basolateral (BLA) and centromedial (CMA) amygdala in 19 sexually abused adolescents with PTSD relative to 23 matched controls. Additionally, we examined whether altered amygdala subregional connectivity coincides with abnormal grey matter volume of the amygdaloid complex. Our analysis revealed abnormal amygdalar connectivity and morphology in adolescent PTSD patients. More specifically, PTSD patients showed diminished right BLA connectivity with a cluster including dorsal and ventral portions of the anterior cingulate and medial prefrontal cortices (p < 0.05, corrected). In contrast, PTSD patients showed increased left CMA connectivity with a cluster including the orbitofrontal and subcallosal cortices (p < 0.05, corrected). Critically, these connectivity changes coincided with diminished grey matter volume within BLA and CMA subnuclei (p < 0.05, corrected), with CMA connectivity shifts additionally relating to more severe symptoms of PTSD. These findings provide unique insights into how perturbations in major amygdalar circuits could hamper fear regulation and drive excessive acquisition and expression of fear in PTSD. As such, they represent an important step toward characterizing the neurocircuitry of adolescent PTSD, thereby informing the development of reliable biomarkers and potential therapeutic targets. PMID:26859310

  7. The K-segments of wheat dehydrin WZY2 are essential for its protective functions under temperature stress

    PubMed Central

    Yang, Wenbo; Zhang, Linsheng; Lv, Hui; Li, He; Zhang, Yane; Xu, Yang; Yu, Jianing

    2015-01-01

    Dehydrins (DHNs), group 2 of late embryogenesis abundant (LEA) proteins, are up-regulated in most plants during cold, drought, heat, or salinity stress. All DHNs contain at least one K-segment, which is believed to play a significant role in DHN function by forming an amphipathic helix. In previous studies, wzy2, an YSK2-type DHN gene, was isolated from the Zhengyin 1 cultivar of Triticum aestivum under cold and drought stress treatment conditions. Four WZY2 truncated derivatives were constructed to knock out the K-, Y- or S-segment, which potentially affect the function of the protein. In vivo assays of Escherichia coli viability enhancement, in vitro lactate dehydrogenase (LDH) activity protection and ex vivo protein aggregation prevention assays revealed that WZY2 acted as a protectant and improved stress tolerance during temperature variation. The results also showed that unlike the truncated derivative without K-segments, the derivative containing two K-segments had remarkable effects that were similar to those of full-length WZY2, indicating that the K-segment is the major functional component of WZY2. Moreover, compared with the other segments, the first K-segment might be the most critical contributor to WZY2 functionality. In general, this work highlights the behavior of DHNs in relieving cold stress ex vivo and the contribution of the K-segment to DHN function. PMID:26124763

  8. The K-segments of wheat dehydrin WZY2 are essential for its protective functions under temperature stress.

    PubMed

    Yang, Wenbo; Zhang, Linsheng; Lv, Hui; Li, He; Zhang, Yane; Xu, Yang; Yu, Jianing

    2015-01-01

    Dehydrins (DHNs), group 2 of late embryogenesis abundant (LEA) proteins, are up-regulated in most plants during cold, drought, heat, or salinity stress. All DHNs contain at least one K-segment, which is believed to play a significant role in DHN function by forming an amphipathic helix. In previous studies, wzy2, an YSK2-type DHN gene, was isolated from the Zhengyin 1 cultivar of Triticum aestivum under cold and drought stress treatment conditions. Four WZY2 truncated derivatives were constructed to knock out the K-, Y- or S-segment, which potentially affect the function of the protein. In vivo assays of Escherichia coli viability enhancement, in vitro lactate dehydrogenase (LDH) activity protection and ex vivo protein aggregation prevention assays revealed that WZY2 acted as a protectant and improved stress tolerance during temperature variation. The results also showed that unlike the truncated derivative without K-segments, the derivative containing two K-segments had remarkable effects that were similar to those of full-length WZY2, indicating that the K-segment is the major functional component of WZY2. Moreover, compared with the other segments, the first K-segment might be the most critical contributor to WZY2 functionality. In general, this work highlights the behavior of DHNs in relieving cold stress ex vivo and the contribution of the K-segment to DHN function. PMID:26124763

  9. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus

    PubMed Central

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M.

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  10. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus.

    PubMed

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  11. The Relationship of Metabolic Syndrome with Stress, Coronary Heart Disease and Pulmonary Function - An Occupational Cohort-Based Study

    PubMed Central

    Nowobilski, Roman; Dropinski, Jerzy; Kotula-Horowitz, Katarzyna; Laskowicz, Bartosz; Stanisz, Andrzej; Lelakowski, Jacek

    2015-01-01

    Background and Aims Higher levels of stress impact the prevalence of metabolic syndrome (MetS) and coronary heart disease. The association between MetS, impaired pulmonary function and low level of physical activity is still pending assessment in the subjects exposed to stress. The study aimed to examine whether higher levels of stress might be related to MetS and the plaque presence, as well as whether MetS might affect pulmonary function. Design and Methods The study embraced 235 police officers (mean age 40.97 years) from the south of Poland. The anthropometrics and biochemical variables were measured; MetS was diagnosed using the International Diabetes Federation criteria. Computed tomography coronary angiography of coronary arteries, exercise ECG, measurements of brachial flow-mediated dilation, and carotid artery intima-media thickness were completed. In order to measure the self-perception of stress, 10-item Perceived Stress Scale (PSS-10) was applied. Pulmonary function and physical activity levels were also addressed. Multivariate logistic regression analyses were applied to determine the relationships between: 1/ incidence of coronary plaque and MetS per se, MetS components and the number of classical cardiovascular risk factors, 2/ perceived stress and MetS, 3/ MetS and pulmonary function parameters. Results Coronary artery atherosclerosis was less associated with MetS (OR = 2.62, 95%CI 1.24–5.52; p = 0.011) than with a co-existence of classical cardiovascular risk factors (OR = 5.67, 95% CI 1.07–29.85, p = 0.03; for 3 risk factors and OR = 9.05; 95% CI 1.24–66.23, p = 0.02; for 6 risk factors, respectively). Perceived stress increased MetS prevalence (OR = 1.07, 95% CI 1.03–1.13; p = 0.03), and impacted coronary plaque prevalence (OR = 1.05, 95% CI 1.001–1.10; p = 0.04). Leisure-time physical activity reduced the chances of developing MetS (OR = 0.98 95% CI 0.96–0.99; p = 0.02). MetS subjects had significantly lower values of certain

  12. Loss of Arabidopsis 5'-3' Exoribonuclease AtXRN4 Function Enhances Heat Stress Tolerance of Plants Subjected to Severe Heat Stress.

    PubMed

    Nguyen, Anh Hai; Matsui, Akihiro; Tanaka, Maho; Mizunashi, Kayoko; Nakaminami, Kentaro; Hayashi, Makoto; Iida, Kei; Toyoda, Tetsuro; Nguyen, Dong Van; Seki, Motoaki

    2015-09-01

    mRNA degradation plays an important role in the rapid and dynamic alteration of gene expression in response to environmental stimuli. Arabidopsis 5'-3' exoribonuclease (AtXRN4), a homolog of yeast Xrn1p, functions after a de-capping step in the degradation of uncapped RNAs. While Xrn1p-dependent degradation of mRNA is the main process of mRNA decay in yeast, information pertaining to the targets of XRN4-based degradation in plants is limited. In order to better understand the biological function of AtXRN4, the current study examined the survivability of atxrn4 mutants subjected to heat stress. The results indicated that atxrn4 mutants, compared with wild-type plants, exhibited an increased survival rate when subjected to a short-term severe heat stress. A microarray and mRNA decay assay showed that loss of AtXRN4 function caused a reduction in the degradation of heat shock factor A2 (HSFA2) and ethylene response factor 1 (ERF1) mRNA. The heat stress tolerance phenotype of atxrn4 mutants was significantly reduced or lost by mutation of HSFA2, a known key regulator of heat acclimation, thus indicating that HSFA2 is a target gene of AtXRN4-mediated mRNA degradation both under non-stress conditions and during heat acclimation. These results demonstrate that AtXRN4-mediated mRNA degradation is linked to the suppression of heat acclimation. PMID:26136597

  13. Taxonomic and Functional Diversity Provides Insight into Microbial Pathways and Stress Responses in the Saline Qinghai Lake, China

    PubMed Central

    Dong, Hailiang; Jiang, Hongchen; Wu, Geng; Edwardson, Christian; De Vlaminck, Iwijn; Quake, Stephen

    2014-01-01

    Microbe-mediated biogeochemical cycles contribute to the global climate system and have sensitive responses and feedbacks to environmental stress caused by climate change. Yet, little is known about the effects of microbial biodiversity (i.e., taxonmic and functional diversity) on biogeochemical cycles in ecosytems that are highly sensitive to climate change. One such sensitive ecosystem is Qinghai Lake, a high-elevation (3196 m) saline (1.4%) lake located on the Tibetan Plateau, China. This study provides baseline information on the microbial taxonomic and functional diversity as well as the associated stress response genes. Illumina metagenomic and metatranscriptomic datasets were generated from lake water samples collected at two sites (B and E). Autotrophic Cyanobacteria dominated the DNA samples, while heterotrophic Proteobacteria dominated the RNA samples at both sites. Photoheterotrophic Loktanella was also present at both sites. Photosystem II was the most active pathway at site B; while, oxidative phosphorylation was most active at site E. Organisms that expressed photosystem II or oxidative phosphorylation also expressed genes involved in photoprotection and oxidative stress, respectively. Assimilatory pathways associated with the nitrogen cycle were dominant at both sites. Results also indicate a positive relationship between functional diversity and the number of stress response genes. This study provides insight into the stress resilience of microbial metabolic pathways supported by greater taxonomic diversity, which may affect the microbial community response to climate change. PMID:25365331

  14. Taxonomic and functional diversity provides insight into microbial pathways and stress responses in the saline Qinghai Lake, China.

    PubMed

    Huang, Qiuyuan; Briggs, Brandon R; Dong, Hailiang; Jiang, Hongchen; Wu, Geng; Edwardson, Christian; De Vlaminck, Iwijn; Quake, Stephen

    2014-01-01

    Microbe-mediated biogeochemical cycles contribute to the global climate system and have sensitive responses and feedbacks to environmental stress caused by climate change. Yet, little is known about the effects of microbial biodiversity (i.e., taxonmic and functional diversity) on biogeochemical cycles in ecosytems that are highly sensitive to climate change. One such sensitive ecosystem is Qinghai Lake, a high-elevation (3196 m) saline (1.4%) lake located on the Tibetan Plateau, China. This study provides baseline information on the microbial taxonomic and functional diversity as well as the associated stress response genes. Illumina metagenomic and metatranscriptomic datasets were generated from lake water samples collected at two sites (B and E). Autotrophic Cyanobacteria dominated the DNA samples, while heterotrophic Proteobacteria dominated the RNA samples at both sites. Photoheterotrophic Loktanella was also present at both sites. Photosystem II was the most active pathway at site B; while, oxidative phosphorylation was most active at site E. Organisms that expressed photosystem II or oxidative phosphorylation also expressed genes involved in photoprotection and oxidative stress, respectively. Assimilatory pathways associated with the nitrogen cycle were dominant at both sites. Results also indicate a positive relationship between functional diversity and the number of stress response genes. This study provides insight into the stress resilience of microbial metabolic pathways supported by greater taxonomic diversity, which may affect the microbial community response to climate change. PMID:25365331

  15. A SAL1 Loss-of-Function Arabidopsis Mutant Exhibits Enhanced Cadmium Tolerance in Association with Alleviation of Endoplasmic Reticulum Stress.

    PubMed

    Xi, Hongmei; Xu, Hua; Xu, Wenxiu; He, Zhenyan; Xu, Wenzhong; Ma, Mi

    2016-06-01

    SAL1, as a negative regulator of stress response signaling, has been studied extensively for its role in plant response to environmental stresses. However, the role of SAL1 in cadmium (Cd) stress response and the underlying mechanism is still unclear. Using an Arabidopsis thaliana loss-of-function mutant of SAL1, we assessed Cd resistance and further explored the Cd toxicity mechanism through analysis of the endoplasmic reticulum (ER) stress response. The loss of SAL1 function greatly improved Cd tolerance and significantly attenuated ER stress in Arabidopsis. Exposure to Cd induced an ER stress response in Arabidopsis as evidenced by unconventional splicing of AtbZIP60 and up-regulation of ER stress-responsive genes. Damage caused by Cd was markedly reduced in the ER stress response double mutant bzip28 bzip60 or by application of the ER stress-alleviating chemical agents, tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (4-PBA), in wild-type plants. The Cd-induced ER stress in Arabidopsis was also alleviated by loss of function of SAL1. These results identified SAL1 as a new component mediating Cd toxicity and established the role of the ER stress response in Cd toxicity. Additionally, the attenuated ER stress in the sal1 mutant might also shed new light on the mechanism of diverse abiotic stress resistance in the SAL1 loss-of-function mutants. PMID:27044671

  16. Alterations of CNS structure & function by charged particle radiation & resultant oxidative stress

    NASA Astrophysics Data System (ADS)

    Nelson, Gregory; Chang, Polly; Favre, Cecile; Fike, John; Komarova, Natalia; Limoli, Charles; Mao, Xiao-Wen; Obenaus, Andre; Raber, Jacob; Spigelman, Igor; Soltesz, Ivan; Song, Sheng-Kwei; Stampanoni, Marco; Vlkolinsky, Roman; Wodarz, Dominik

    were complex and suggested continuous remodeling of the brain for up to 6 months. Thus we demonstrated a suite of CNS structural and functional changes after proton and iron ion exposure in the low dose regime. Based on these findings we will now test whether oxidative stress mediates the reactions of CNS to radiation exposure and what role radiation quality and dose rate play in the responses. We will use cultured neural precursor cells (mouse human) to detect changes in oxidative status and differentiation as functions of charged particle charge and velocity. These results will inform the selection of particles for many in vivo measurements that will compare wild type mice to a transgenic strain that over-expresses a human catalase gene (which inactivates hydrogen peroxide) in the mitochondrial compartment. This will explicitly test the role of reactive oxygen species in mediating the mechanisms underlying the CNS endpoints that we will measure. We will extend the electrophysiological measurements on individual nerves in hippocampal slices to characterize both inhibitory and excitatory synapses. Further, multi-electrode arrays will be used to follow correlated electrical activity in different hippocampal regions in order to understand network-level function as well as synaptic efficacy and plasticity. Controlled oxidative stress on irradiated samples will explore whether response mechanisms are shared. To link alterations in neurogenesis to performance we will explore behavioral changes mediated by the hippocampus simultaneously with measures of expression of the Arc gene in newly-born neurons. This will test whether decrements in performance correlate with loss of new cells and whether behavior properly stimulates functional integration of the new cells; the behavioral paradigm will be contextual fear conditioning. We will develop mathematical frameworks for CNS responses to radiation in order to inform risk estimates. Finally, we will couple a high

  17. Circulating angiogenic cell function is inhibited by cortisol in vitro and associated with psychological stress and cortisol in vivo.

    PubMed

    Aschbacher, Kirstin; Derakhshandeh, Ronak; Flores, Abdiel J; Narayan, Shilpa; Mendes, Wendy Berry; Springer, Matthew L

    2016-05-01

    Psychological stress and glucocorticoids are associated with heightened cardiovascular disease risk. We investigated whether stress or cortisol would be associated with reduced circulating angiogenic cell (CAC) function, an index of impaired vascular repair. We hypothesized that minority-race individuals who experience threat in interracial interactions would exhibit reduced CAC function, and that this link might be explained by cortisol. To test this experimentally, we recruited 106 African American participants for a laboratory interracial interaction task, in which they received socially evaluative feedback from Caucasian confederates. On a separate day, a subset of 32 participants (mean age=26years, 47% female) enrolled in a separate biological substudy and provided blood samples for CAC isolation and salivary samples to quantify the morning peak in cortisol (the cortisol awakening response, CAR). CAC function was quantified using cell culture assays of migration to vascular endothelial growth factor (VEGF) and secretion of VEGF into the culture medium. Heightened threat in response to an interracial interaction and trait anxiety in vivo were both associated with poorer CAC migratory function in vitro. Further, threat and poorer sustained attention during the interracial interaction were associated with a higher CAR, which in turn, was related to lower CAC sensitivity to glucocorticoids. In vitro, higher doses of cortisol impaired CAC migratory function and VEGF protein secretion. The glucocorticoid receptor antagonist RU486 reversed this functional impairment. These data identify a novel, neuroendocrine pathway by which psychological stress may reduce CAC function, with potential implications for cardiovascular health. PMID:26925833

  18. Chilling acclimation provides immunity to stress by altering regulatory networks and inducing genes with protective functions in Cassava

    PubMed Central

    2014-01-01

    Background Stress acclimation is an effective mechanism that plants acquired for adaption to dynamic environment. Even though generally considered to be sensitive to low temperature, Cassava, a major tropical crop, can be tolerant to much lower temperature after chilling acclimation. Improvement to chilling resistance could be beneficial to breeding. However, the underlying mechanism and the effects of chilling acclimation on chilling tolerance remain largely unexplored. Results In order to understand the mechanism of chilling acclimation, we profiled and analyzed the transcriptome and microRNAome of Cassava, using high-throughput deep sequencing, across the normal condition, a moderate chilling stress (14°C), a harsh stress (4°C) after chilling acclimation (14°C), and a chilling shock from 24°C to 4°C. The results revealed that moderate stress and chilling shock triggered comparable degrees of transcriptional perturbation, and more importantly, about two thirds of differentially expressed genes reversed their expression from up-regulation to down-regulation or vice versa in response to hash stress after experiencing moderate stress. In addition, microRNAs played important roles in the process of this massive genetic circuitry rewiring. Furthermore, function analysis revealed that chilling acclimation helped the plant develop immunity to further harsh stress by exclusively inducing genes with function for nutrient reservation therefore providing protection, whereas chilling shock induced genes with function for viral reproduction therefore causing damage. Conclusions Our study revealed, for the first time, the molecular basis of chilling acclimation, and showed potential regulation role of microRNA in chilling response and acclimation in Euphorbia. PMID:25090992

  19. Mechanisms of change: Testing how preventative interventions impact psychological and physiological stress functioning in mothers in neglectful families.

    PubMed

    Toth, Sheree L; Sturge-Apple, Melissa L; Rogosch, Fred A; Cicchetti, Dante

    2015-11-01

    The present study applies a multilevel approach to an examination of the effect of two randomized preventive interventions with mothers in neglectful families who are also contending with elevated levels of impoverishment and ecological risk. Specifically, we examined how participation in either child-parent psychotherapy (CPP) or psychoeducational parenting intervention (PPI) was associated with reductions in maternal psychological parenting stress and in turn physiological stress system functioning when compared to mothers involved in standard community services as well as a demographic comparison group of nonmaltreating mothers. The resulting group sizes in the current investigation were 44 for CPP, 34 for PPI, 27 for community services, and 52 for nonmaltreating mothers. Mothers and their 13-month-old infants were randomly assigned to intervention group at baseline. Mothers completed assessments on stress within the parenting role at baseline and postintervention. Basal cortisol was sampled at postintervention and 1-year follow-up. Latent difference score analyses examined change in these constructs over time. Results suggested that mothers within the CPP intervention experienced significant declines in child-related parenting stress, while mothers in the PPI intervention reported declines in parent-related parenting stress. In turn, significant decreases in stress within the CPP mothers were further associated with adaptive basal cortisol functioning at 1-year postintervention. The results highlight the value of delineating how participation in preventive interventions aimed at ameliorating child maltreatment in neglectful families within the context of poverty may operate through improvements in psychological and physiological stress functioning. Findings are discussed with respect to the importance of multilevel assessments of intervention process and outcome. PMID:26535951

  20. Mechanisms of Change: Testing how Preventative Interventions Impact Psychological and Physiological Stress Functioning in Mothers in Neglectful Families

    PubMed Central

    Toth, Sheree L.; Sturge-Apple, Melissa L.; Rogosch, Fred A.; Cicchetti, Dante

    2015-01-01

    The present study applies a multilevel approach to an examination of the effect of two randomized preventative interventions with mothers in neglectful families who are also contending with elevated levels of impoverishment and ecological risk. Specifically, we examined how participation in either Child-Parent Psychotherapy (CPP) or Psychoeducational Parenting (PPI) interventions was associated with reductions in maternal psychological parenting stress and in turn physiological stress system functioning when compared to mothers involved in standard community services (CS) as well as a demographic comparison group of nonmaltreating mothers (NC). The resulting group sizes in the current investigation were: CPP (n = 44), PPI (n = 34), CS (n = 27), and NC (n = 52). Mothers and infants who were 13-months of age were randomly assigned to intervention group at baseline. Mothers completed assessments on stress within the parenting role at baseline and post-intervention. Basal cortisol was sampled at post-intervention and 1-year follow-up. Latent difference score analyses examined change in these constructs over time. Results suggested that mothers within the CPP intervention experienced significant declines in child-related parenting stress while mothers in the PPI intervention reported declines in parent-related parenting stress. In turn, significant decreases in stress within the CPP mothers were further associated with adaptive basal cortisol functioning at 1-year post-intervention. Results highlight the value of delineating how participation in preventtive interventions aimed at ameliorating child maltreatment in neglectful families within the context of poverty may operate through improvements in psychological and physiological stress functioning. Findings are discussed with respect to the importance of multi-level assessments of intervention process and outcome. PMID:26535951

  1. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels.

    PubMed

    Guérineau, Nathalie C; Desarménien, Michel G; Carabelli, Valentina; Carbone, Emilio

    2012-10-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca(2+) signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca(2+) channels that are directly involved in Ca(2+)-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  2. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels

    PubMed Central

    Guérineau, Nathalie C.; Desarménien, Michel G.; Carabelli, Valentina; Carbone, Emilio

    2012-01-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca2+ signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca2+ channels that are directly involved in Ca2+-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  3. Functional analysis of atfA gene to stress response in pathogenic thermal dimorphic fungus Penicillium marneffei.

    PubMed

    Nimmanee, Panjaphorn; Woo, Patrick C Y; Vanittanakom, Pramote; Youngchim, Sirida; Vanittanakom, Nongnuch

    2014-01-01

    Penicillium marneffei, the pathogenic thermal dimorphic fungus is a causative agent of a fatal systemic disease, penicilliosis marneffei, in immunocompromised patients especially HIV patients. For growth and survival, this fungus has to adapt to environmental stresses outside and inside host cells and this adaptation requires stress signaling pathways and regulation of gene expression under various kinds of stresses. In this report, P. marneffei activating transcription factor (atfA) gene encoding bZip-type transcription factor was characterized. To determine functions of this gene, atfA isogenic mutant strain was constructed using the modified split marker recombination method. The phenotypes and susceptibility to varieties of stresses including osmotic, oxidative, heat, UV, cell wall and cell membrane stresses of the mutant strain were compared with the wild type and the atfA complemented strains. Results demonstrated that the mRNA expression level of P. marneffei atfA gene increased under heat stress at 42°C. The atfA mutant was more sensitive to sodium dodecyl sulphate, amphotericin B and tert-butyl hydroperoxide than the wild type and complemented strains but not hydrogen peroxide, menadione, NaCl, sorbitol, calcofluor white, itraconazole, UV stresses and heat stress at 39°C. In addition, recovery of atfA mutant conidia after mouse and human macrophage infections was significantly decreased compared to those of wild type and complemented strains. These results indicated that the atfA gene was required by P. marneffei under specific stress conditions and might be necessary for fighting against host immune cells during the initiation of infection. PMID:25365258

  4. Docosahexaenoic acid reduces ER stress and abnormal protein accumulation and improves neuronal function following traumatic brain injury.

    PubMed

    Begum, Gulnaz; Yan, Hong Q; Li, Liaoliao; Singh, Amneet; Dixon, C Edward; Sun, Dandan

    2014-03-01

    In this study, we investigated the development of endoplasmic reticulum (ER) stress after traumatic brain injury (TBI) and the efficacy of post-TBI administration of docosahexaenoic acid (DHA) in reducing ER stress. TBI was induced by cortical contusion injury in Sprague-Dawley rats. Either DHA (16 mg/kg in DMSO) or vehicle DMSO (1 ml/kg) was administered intraperitoneally at 5 min after TBI, followed by a daily dose for 3-21 d. TBI triggered sustained expression of the ER stress marker proteins including phosphorylated eukaryotic initiation factor-2α, activating transcription factor 4, inositol requiring kinase 1, and C/EBP homologous protein in the ipsilateral cortex at 3-21 d after TBI. The prolonged ER stress was accompanied with an accumulation of abnormal ubiquitin aggregates and increased expression of amyloid precursor protein (APP) and phosphorylated tau (p-Tau) in the frontal cortex after TBI. The ER stress marker proteins were colocalized with APP accumulation in the soma. Interestingly, administration of DHA attenuated all ER stress marker proteins and reduced the accumulation of both ubiquitinated proteins and APP/p-Tau proteins. In addition, the DHA-treated animals exhibited early recovery of their sensorimotor function after TBI. In summary, our study demonstrated that TBI induces a prolonged ER stress, which is positively correlated with abnormal APP accumulation. The sustained ER stress may play a role in chronic neuronal damage after TBI. Our findings illustrate that post-TBI administration of DHA has therapeutic potentials in reducing ER stress, abnormal protein accumulation, and neurological deficits. PMID:24599472

  5. Induction of oxidative stress causes functional alterations in mouse urothelium via a TRPM8-mediated mechanism: implications for aging

    PubMed Central

    Nocchi, Linda; Daly, Donna M; Chapple, Christopher; Grundy, David

    2014-01-01

    The incidence of bladder conditions such as overactive bladder syndrome and its associated urinary incontinence is highly prevalent in the elderly. However, the mechanisms underlying these disorders are unclear. Studies suggest that the urothelium forms a ‘sensory network’ with the underlying innervation, alterations in which, could compromise bladder function. As the accumulation of reactive oxygen species can cause functional alterations with age, the aim of this study was to investigate whether oxidative stress alters urothelial sensory signalling and whether the mechanism underlying the effect of oxidative stress on the urothelium plays a role in aging. Five-month-old(young) and 24-month-old (aged) mice were used. H2O2, used to induce oxidative stress, resulted in an increase in bladder afferent nerve activity and urothelial intracellular calcium in preparations from young mice. These functional changes were concurrent with upregulation of TRPM8 in the urothelium. Moreover, application of a TRPM8 antagonist significantly attenuated the H2O2-induced calcium responses. Interestingly, an upregulation of TRPM8 was also found in the urothelium from aged mice, where high oxidative stress levels were observed, together with a greater calcium response to the TRPM8 agonist WS12. Furthermore, these calcium responses were attenuated by pretreatment with the antioxidant N-acetyl-cysteine. This study shows that oxidative stress affects urothelial function involving a TRPM8-mediated mechanism and these effects may have important implications for aging. These data provide an insight into the possible mechanisms by which oxidative stress causes physiological alterations in the bladder, which may also occur in other organs susceptible to aging. PMID:24593692

  6. Exercise, Diet, and Stress Management as Mediators between Functional Disability and Health-Related Quality of Life in Multiple Sclerosis

    ERIC Educational Resources Information Center

    Sung, Connie; Chiu, Chung-Yi; Lee, Eun-Jeong; Bezyak, Jill; Chan, Fong; Muller, Veronica

    2013-01-01

    The main objective of this study was to examine the mediational and moderational effect of exercise, diet, and stress management on the relationship between functional disability and health-related quality of life. Quantitative descriptive research design using multiple regression and correlation techniques was used. Participants were 215…

  7. Posttraumatic Stress Disorder Symptom Structure in Injured Children: Functional Impairment and Depression Symptoms in a Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Kassam-Adams, Nancy; Marsac, Meghan L.; Cirilli, Carla

    2010-01-01

    Objective: To examine the factor structure of posttraumatic stress disorder (PTSD) symptoms in children and adolescents who have experienced an acute single-incident trauma, associations between PTSD symptom clusters and functional impairment, and the specificity of PTSD symptoms in relation to depression and general distress. Method: Examined…

  8. Virial theorem for an inhomogeneous medium, boundary conditions for the wave functions, and stress tensor in quantum statistics.

    PubMed

    Bobrov, V B; Trigger, S A; van Heijst, G J F; Schram, P P J M

    2010-07-01

    On the basis of the stationary Schrödinger equation, the virial theorem in an inhomogeneous external field for the canonical ensemble is proved. It is shown that the difference in the form of virial theorem is conditioned by the value of the wave-function derivative on the surface of the volume, surrounding the system under consideration. The stress tensor in such a system is determined by the average values of the wave-function space derivatives. PMID:20866550

  9. Inter-Annual Variability of Soil Moisture Stress Function in the Wheat Field

    NASA Astrophysics Data System (ADS)

    Akuraju, V. R.; Ryu, D.; George, B.; Ryu, Y.; Dassanayake, K. B.

    2014-12-01

    Root-zone soil moisture content is a key variable that controls the exchange of water and energy fluxes between land and atmosphere. In the soil-vegetation-atmosphere transfer (SVAT) schemes, the influence of root-zone soil moisture on evapotranspiration (ET) is parameterized by the soil moisture stress function (SSF). Dependence of actual ET: potential ET (fPET) or evaporative fraction to the root-zone soil moisture via SSF can also be used inversely to estimate root-zone soil moisture when fPET is estimated by remotely sensed land surface states. In this work we present fPET versus available soil water (ASW) in the root zone observed in the experimental farm sites in Victoria, Australia in 2012-2013. In the wheat field site, fPET vs ASW exhibited distinct features for different soil depth, net radiation, and crop growth stages. Interestingly, SSF in the wheat field presented contrasting shapes for two cropping years of 2012 and 2013. We argue that different temporal patterns of rainfall (and resulting soil moisture) during the growing seasons in 2012 and 2013 are responsible for the distinctive SSFs. SSF of the wheat field was simulated by the Agricultural Production Systems sIMulator (APSIM). The APSIM was able to reproduce the observed fPET vs. ASW. We discuss implications of our findings for existing modeling and (inverse) remote sensing approaches relying on SSF and alternative growth-stage-dependent SSFs.

  10. Label-free microscopy and stress responses reveal the functional organization of Pseudodiaptomus marinus copepod myofibrils.

    PubMed

    Ibrahim, Ali; Hage, Charles Henri; Souissi, Anissa; Leray, Aymeric; Héliot, Laurent; Souissi, Sami; Vandenbunder, Bernard

    2015-08-01

    Pseudodiaptomus marinus copepods are small crustaceans living in estuarine areas endowed with exceptional swimming and adaptative performances. Since the external cuticle acts as an impermeable barrier for most dyes and molecular tools for labeling copepod proteins with fluorescent tags are not available, imaging cellular organelles in these organisms requires label free microscopy. Complementary nonlinear microscopy techniques have been used to investigate the structure and the response of their myofibrils to abrupt changes of temperature or/and salinity. In contrast with previous observations in vertebrates and invertebrates, the flavin autofluorescence which is a signature of mitochondria activity and the Coherent Anti-Stokes Raman Scattering (CARS) pattern assigned to T-tubules overlapped along myofibrils with the second harmonic generation (SHG) striated pattern generated by myosin tails in sarcomeric A bands. Temperature jumps from 18 to 4 °C or salinity jumps from 30 to 15 psu mostly affected flavin autofluorescence. Severe salinity jumps from 30 to 0 psu dismantled myofibril organization with major changes both in the SHG and CARS patterns. After a double stress (from 18 °C/30 psu to 4° C/0 psu) condensed and distended regions appeared within single myofibrils, with flavin autofluorescence bands located between sarcomeric A bands. These results shed light on the interactions between the different functional compartments which provide fast acting excitation-contraction coupling and adequate power supply in copepods muscles. PMID:26057347

  11. Interconnection of tectonic stresses in the Earth's crust and dynamics of the groundwater basin functioning

    NASA Astrophysics Data System (ADS)

    Koneshov, Vycheslav; Trifonova, Tatiana; Trifonov, Dmitriy; Arakelian, Sergey

    2016-04-01

    1. Possible influence of tectonic stresses on the occurrence of catastrophic floods by the mechanism of modification of the 3D-cracknet of the rock formations and the transit of the groundwater in this natural transport system in the conditions of functioning of the river catchment basin is discussed. Several floods (not freshets) took place in 2013-2014, which probably could be associated with corresponding seismic processes in the Earth's crust, are considered. 2. A river basin formation in the mountain slope can be considered as a self-organizing staged process of its evolution passing through several non-equilibrium but steady-state conditions. The controlling parameter is the process of the crack spreading out. Crack development up the slope but downward substance transit, stipulates a feedback within the unified 3D-river basin system. 3. We have briefly described and rendered the mechanism of the influence of seismic activity on the occurrence of concrete floods with the use of combined maps of groundwater resources and the boundaries of lithospheric plates on the territory and the revealed regularities in seismic waves propagation and interaction with groundwater. 4. In the practical aspect a proposed hypothesis can be useful during the definition of potentially dangerous areas for catastrophic water events taking into account the interference of the state of the underground hydrosphere and the tectonic structure of the rheological section of bowels of the earth on the concrete territories under some adjustable (seismic) conditions.

  12. Effects of childhood poverty and chronic stress on emotion regulatory brain function in adulthood.

    PubMed

    Kim, Pilyoung; Evans, Gary W; Angstadt, Michael; Ho, S Shaun; Sripada, Chandra S; Swain, James E; Liberzon, Israel; Phan, K Luan

    2013-11-12

    Childhood poverty has pervasive negative physical and psychological health sequelae in adulthood. Exposure to chronic stressors may be one underlying mechanism for childhood poverty-health relations by influencing emotion regulatory systems. Animal work and human cross-sectional studies both suggest that chronic stressor exposure is associated with amygdala and prefrontal cortex regions important for emotion regulation. In this longitudinal functional magnetic resonance imaging study of 49 participants, we examined associations between childhood poverty at age 9 and adult neural circuitry activation during emotion regulation at age 24. To test developmental timing, concurrent, adult income was included as a covariate. Adults with lower family income at age 9 exhibited reduced ventrolateral and dorsolateral prefrontal cortex activity and failure to suppress amygdala activation during effortful regulation of negative emotion at age 24. In contrast to childhood income, concurrent adult income was not associated with neural activity during emotion regulation. Furthermore, chronic stressor exposure across childhood (at age 9, 13, and 17) mediated the relations between family income at age 9 and ventrolateral and dorsolateral prefrontal cortex activity at age 24. The findings demonstrate the significance of childhood chronic stress exposures in predicting neural outcomes during emotion regulation in adults who grew up in poverty. PMID:24145409

  13. IFNα/βR Signaling Promotes Regulatory T Cell Development and Function Under Stress Conditions

    PubMed Central

    Metidji, Amina; Rieder, Sadiye Amcaoglu; Glass, Deborah Dacek; Cremer, Isabelle; Punkosdy, George A.; Shevach, Ethan M.

    2015-01-01

    Type I IFNs are a family of cytokines with antiviral and immunomodulatory properties. While the antiviral effects of IFNs are well characterized, their immunomodulatory properties are less clear. To specifically address the effects of type I IFNs on Treg, we studied mixed bone morrow (BM) chimeras between wild-type (WT) and IFNα/βR (IFNAR) knockout (KO) mice, and heterozygous female mice expressing a Treg-specific deletion of the IFNAR. In these two models, IFNAR signaling promotes the development of the Treg lineage in the thymus and their survival in the periphery. IFNAR KO Treg had a higher expression of the pro-apoptotic gene Bim and higher frequency of active caspase positive cells. IFNAR KO Treg from chimeric mice displayed a more naïve phenotype, accompanied by lower levels of CD25 and phosphorylated STAT5. Therefore, in Treg IFNAR signaling may directly or indirectly affect phosphorylation of STAT5. In mixed chimeras with Scurfy fetal liver, Treg derived from IFNAR KO BM were unable to control T effector cell activation and tissue inflammation. Under stress conditions or in a competitive environment, IFNAR signaling may be required to maintain Treg homeostasis and function. PMID:25795758

  14. Functional genomics and proteomics of the cellular osmotic stress response in 'non-model' organisms.

    PubMed

    Kültz, Dietmar; Fiol, Diego; Valkova, Nelly; Gomez-Jimenez, Silvia; Chan, Stephanie Y; Lee, Jinoo

    2007-05-01

    All organisms are adapted to well-defined extracellular salinity ranges. Osmoregulatory mechanisms spanning all levels of biological organization, from molecules to behavior, are central to salinity adaptation. Functional genomics and proteomics approaches represent powerful tools for gaining insight into the molecular basis of salinity adaptation and euryhalinity in animals. In this review, we discuss our experience in applying such tools to so-called 'non-model' species, including euryhaline animals that are well-suited for studies of salinity adaptation. Suppression subtractive hybridization, RACE-PCR and mass spectrometry-driven proteomics can be used to identify genes and proteins involved in salinity adaptation or other environmental stress responses in tilapia, sharks and sponges. For protein identification in non-model species, algorithms based on sequence homology searches such as MSBLASTP2 are most powerful. Subsequent gene ontology and pathway analysis can then utilize sets of identified genes and proteins for modeling molecular mechanisms of environmental adaptation. Current limitations for proteomics in non-model species can be overcome by improving sequence coverage, N- and C-terminal sequencing and analysis of intact proteins. Dependence on information about biochemical pathways and gene ontology databases for model species represents a more severe barrier for work with non-model species. To minimize such dependence, focusing on a single biological process (rather than attempting to describe the system as a whole) is key when applying 'omics' approaches to non-model organisms. PMID:17449824

  15. Low oxygen alters mitochondrial function and response to oxidative stress in human neural progenitor cells

    PubMed Central

    Lages, Yury M.; Nascimento, Juliana M.; Lemos, Gabriela A.; Galina, Antonio; Castilho, Leda R.

    2015-01-01

    Oxygen concentration should be carefully regulated in all living tissues, beginning at the early embryonic stages. Unbalances in oxygen regulation can lead to cell death and disease. However, to date, few studies have investigated the consequences of variations in oxygen levels for fetal-like cells. Therefore, in the present work, human neural progenitor cells (NPCs) derived from pluripotent stem cells grown in 3% oxygen (v/v) were compared with NPCs cultured in 21% (v/v) oxygen. Low oxygen concentrations altered the mitochondrial content and oxidative functions of the cells, which led to improved ATP production, while reducing generation of reactive oxygen species (ROS). NPCs cultured in both conditions showed no differences in proliferation and glucose metabolism. Furthermore, antioxidant enzymatic activity was not altered in NPCs cultured in 3% oxygen under normal conditions, however, when exposed to external agents known to induce oxidative stress, greater susceptibility to DNA damage was observed. Our findings indicate that the management of oxygen levels should be considered for in vitro models of neuronal development and drug screening. PMID:26713239

  16. Evidence of early neurobiological alternations in adolescents with posttraumatic stress disorder: a functional MRI study.

    PubMed

    Yang, Pinchen; Wu, Ming-Ting; Hsu, Chia-Chuang; Ker, Jhy-Horng

    2004-11-01

    Neuroimaging studies of patients with posttraumatic stress disorder (PTSD) have largely been performed in adult populations. The purpose of the current study was to investigate neural correlates of PTSD in adolescents. Specifically, this study investigates whether a differential brain response was present during the visual perception and imaginary recollection of traumatic reminders in adolescents who developed PTSD versus those who did not after experiencing earthquake. Eleven Taiwanese adolescents (age range: 12-14 years) with traumatic experience of earthquake were enrolled. Five subjects fulfilled PTSD criteria, while the other six served as non-PTSD controls. Brain activation was measured by functional magnetic resonance image (fMRI) during visual perception and imagery recall of earthquake and neutral pictures at 14 months after earthquake. During earthquake imagery (as compared with neutral imagery), PTSD group demonstrated activation in the bilateral visual cortex, bilateral cerebellum and left parahippocampal gyrus, while control group did not. During earthquake perception (as compared with neutral perception), the control group showed activation over anterior cingulate, but the PTSD group did not. Intergroup comparison confirmed above discrepancies was significant. We concluded that neurobiological alternation of PTSD in adolescent was similar to those in adult and might have developed within 14 months after trauma exposure. PMID:15489009

  17. An Adenylyl Cyclase, CyaA, of Myxococcus xanthus Functions in Signal Transduction during Osmotic Stress

    PubMed Central

    Kimura, Yoshio; Mishima, Yukako; Nakano, Hiromi; Takegawa, Kaoru

    2002-01-01

    An adenylyl cyclase gene (cyaA) present upstream of an osmosensor protein gene (mokA) was isolated from Myxococcus xanthus. cyaA encoded a polypeptide of 843 amino acids with a predicted molecular mass of 91,187 Da. The predicted cyaA gene product had structural similarity to the receptor-type adenylyl cyclases that are composed of an amino-terminal sensor domain and a carboxy-terminal catalytic domain of adenylyl cyclase. In reverse transcriptase PCR experiments, the transcript of the cyaA gene was detected mainly during development and spore germination. A cyaA mutant, generated by gene disruption, showed normal growth, development, and germination. However, a cyaA mutant placed under conditions of ionic (NaCl) or nonionic (sucrose) osmostress exhibited a marked reduction in spore formation and spore germination. When wild-type and cyaA mutant cells at developmental stages were stimulated with 0.2 M NaCl or sucrose, the mutant cells increased cyclic AMP accumulation at levels similar to those of the wild-type cells. In contrast, the mutant cells during spore germination had mainly lost the ability to respond to high-ionic osmolarity. In vegetative cells, the cyaA mutant responded normally to osmotic stress. These results suggested that M. xanthus CyaA functions mainly as an ionic osmosensor during spore germination and that CyaA is also required for osmotic tolerance in fruiting formation and sporulation. PMID:12057952

  18. Effects of childhood poverty and chronic stress on emotion regulatory brain function in adulthood

    PubMed Central

    Kim, Pilyoung; Evans, Gary W.; Angstadt, Michael; Ho, S. Shaun; Sripada, Chandra S.; Swain, James E.; Liberzon, Israel; Phan, K. Luan

    2013-01-01

    Childhood poverty has pervasive negative physical and psychological health sequelae in adulthood. Exposure to chronic stressors may be one underlying mechanism for childhood poverty−health relations by influencing emotion regulatory systems. Animal work and human cross-sectional studies both suggest that chronic stressor exposure is associated with amygdala and prefrontal cortex regions important for emotion regulation. In this longitudinal functional magnetic resonance imaging study of 49 participants, we examined associations between childhood poverty at age 9 and adult neural circuitry activation during emotion regulation at age 24. To test developmental timing, concurrent, adult income was included as a covariate. Adults with lower family income at age 9 exhibited reduced ventrolateral and dorsolateral prefrontal cortex activity and failure to suppress amygdala activation during effortful regulation of negative emotion at age 24. In contrast to childhood income, concurrent adult income was not associated with neural activity during emotion regulation. Furthermore, chronic stressor exposure across childhood (at age 9, 13, and 17) mediated the relations between family income at age 9 and ventrolateral and dorsolateral prefrontal cortex activity at age 24. The findings demonstrate the significance of childhood chronic stress exposures in predicting neural outcomes during emotion regulation in adults who grew up in poverty. PMID:24145409

  19. Redox Modulation Matters: Emerging Functions for Glutaredoxins in Plant Development and Stress Responses

    PubMed Central

    Li, Shutian

    2014-01-01

    Glutaredoxins (GRXs) are small ubiquitous glutathione (GSH)-dependent oxidoreductases that catalyze the reversible reduction of protein disulfide bridges or protein-GSH mixed disulfide bonds via a dithiol or monothiol mechanism, respectively. Three major classes of GRXs, with the CPYC-type, the CGFS-type or the CC-type active site, have been identified in many plant species. In spite of the well-characterized roles for GRXs in Escherichia coli, yeast and humans, the biological functions of plant GRXs have been largely enigmatic. The CPYC-type and CGFS-type GRXs exist in all organisms, from prokaryotes to eukaryotes, whereas the CC-type class has thus far been solely identified in land plants. Only the number of the CC-type GRXs has enlarged dramatically during the evolution of land plants, suggesting their participation in the formation of more complex plants adapted to life on land. A growing body of evidence indicates that plant GRXs are involved in numerous cellular pathways. In this review, emphasis is placed on the recently emerging functions for GRXs in floral organ development and disease resistance. Notably, CC-type GRXs have been recruited to participate in these two seemingly unrelated processes. Besides, the current knowledge of plant GRXs in the assembly and delivery of iron-sulfur clusters, oxidative stress responses and arsenic resistance is also presented. As GRXs require GSH as an electron donor to reduce their target proteins, GSH-related developmental processes, including the control of flowering time and the development of postembryonic roots and shoots, are further discussed. Profiling the thiol redox proteome using high-throughput proteomic approaches and measuring cellular redox changes with fluorescent redox biosensors will help to further unravel the redox-regulated physiological processes in plants. PMID:27135520

  20. Deep transcriptome sequencing reveals the expression of key functional and regulatory genes involved in the abiotic stress signaling pathways in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought, salt and cold are the major abiotic stresses that limit the rice production and cause serious threat to food security. The identification of the key functional and regulatory genes in the abiotic stress signaling pathways is important for understanding the molecular basis of abiotic stress ...

  1. CsPAO4 of Citrus sinensis functions in polyamine terminal catabolism and inhibits plant growth under salt stress

    PubMed Central

    Wang, Wei; Liu, Ji-Hong

    2016-01-01

    Polyamine oxidase (PAO) is a key enzyme catalyzing polyamine catabolism leading to H2O2 production. We previously demonstrated that Citrus sinensis contains six putative PAO genes, but their functions are not well understood. In this work, we reported functional elucidation of CsPAO4 in polyamine catabolism and salt stress response. CsPAO4 was localized to the apoplast and used both spermidine (Spd) and spermine (Spm) as substrates for terminal catabolism. Transgenic plants overexpressing CsPAO4 displayed prominent increase in PAO activity, concurrent with marked decrease of Spm and Spd and elevation of H2O2. Seeds of transgenic lines displayed better germination when compared with wild type (WT) under salt stress. However, both vegetative growth and root elongation of the transgenic lines were prominently inhibited under salt stress, accompanied by higher level of H2O2 and more conspicuous programmed cell death (PCD). Exogenous supply of catalase (CAT), a H2O2 scavenger, partially recovered the vegetative growth and root elongation. In addition, spermine inhibited root growth of transgenic plants. Taken together, these data demonstrated that CsPAO4 accounts for production of H2O2 causing oxidative damages under salt stress and that down-regulation of a PAO gene involved in polyamine terminal catabolism may be an alternative approach for improving salt stress tolerance. PMID:27535697

  2. CsPAO4 of Citrus sinensis functions in polyamine terminal catabolism and inhibits plant growth under salt stress.

    PubMed

    Wang, Wei; Liu, Ji-Hong

    2016-01-01

    Polyamine oxidase (PAO) is a key enzyme catalyzing polyamine catabolism leading to H2O2 production. We previously demonstrated that Citrus sinensis contains six putative PAO genes, but their functions are not well understood. In this work, we reported functional elucidation of CsPAO4 in polyamine catabolism and salt stress response. CsPAO4 was localized to the apoplast and used both spermidine (Spd) and spermine (Spm) as substrates for terminal catabolism. Transgenic plants overexpressing CsPAO4 displayed prominent increase in PAO activity, concurrent with marked decrease of Spm and Spd and elevation of H2O2. Seeds of transgenic lines displayed better germination when compared with wild type (WT) under salt stress. However, both vegetative growth and root elongation of the transgenic lines were prominently inhibited under salt stress, accompanied by higher level of H2O2 and more conspicuous programmed cell death (PCD). Exogenous supply of catalase (CAT), a H2O2 scavenger, partially recovered the vegetative growth and root elongation. In addition, spermine inhibited root growth of transgenic plants. Taken together, these data demonstrated that CsPAO4 accounts for production of H2O2 causing oxidative damages under salt stress and that down-regulation of a PAO gene involved in polyamine terminal catabolism may be an alternative approach for improving salt stress tolerance. PMID:27535697

  3. Identification and Functional Analysis of MicroRNAs and Their Targets in Platanus acerifolia under Lead (Pb) Stress

    PubMed Central

    Wang, Yuanlong; Zhao, Zhenli; Deng, Minjie; Liu, Rongning; Niu, Suyan; Fan, Guoqiang

    2015-01-01

    MicroRNAs (miRNAs) play important regulatory roles in development and stress responses in plants. Lead (Pb) is a non-essential element that is highly toxic to living organisms. Platanus acerifolia is grown as a street tree in cities throughout temperate regions for its importance in improving the urban ecological environment. MiRNAs that respond to abiotic stresses have been identified in plants; however, until now, the influence of Pb stress on P. acerifolia miRNAs has not been reported. To identify miRNAs and predict their target genes under Pb stress, two small RNA and two degradome libraries were constructed from Pb-treated and Pb-free leaves of P. acerifolia seedlings. After sequencing, 55 known miRNAs and 129 novel miRNAs were obtained, and 104 target genes for the miRNAs were identified by degradome sequencing. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to predict the functions of the targets. The expressions of eight differentially expressed miRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). This is the first report about P. acerifolia miRNAs and their target genes under Pb stress. This study has provided data for further research into molecular mechanisms involved in resistance of P. acerifolia to Pb stress. PMID:25830479

  4. Glucocorticoid receptors in the prefrontal cortex regulate stress-evoked dopamine efflux and aspects of executive function

    PubMed Central

    Butts, Kelly A.; Weinberg, Joanne; Young, Allan H.; Phillips, Anthony G.

    2011-01-01

    Enhanced dopamine efflux in the prefrontal cortex is a well-documented response to acute stress. However, the underlying mechanism(s) for this response is unknown. Using in vivo microdialysis, we demonstrate that blocking glucocorticoid receptors locally within the rat prefrontal cortex results in a reduction in stress-evoked dopamine efflux. In contrast, blocking glucocorticoid receptors in the ventral tegmental area did not affect stress-evoked dopamine efflux in the prefrontal cortex. Additionally, local administration of corticosterone into the prefrontal cortex increased prefrontal dopamine efflux. The functional impact of enhanced dopamine efflux evoked by acute stress was demonstrated using a cognitive task dependent on the prefrontal cortex and sensitive to impairment in working memory. Notably, stress-induced impairments in cognition were attenuated by blockade of glucocorticoid receptors in the prefrontal cortex. Taken together, these data demonstrate that glucocorticoids act locally within the prefrontal cortex to modulate mesocortical dopamine efflux leading to the cognitive impairments observed during acute stress. PMID:22032926

  5. Stress sensitivity in metastatic breast cancer: analysis of hypothalamic-pituitary-adrenal axis function.

    PubMed

    Spiegel, David; Giese-Davis, Janine; Taylor, C Barr; Kraemer, Helena

    2006-11-01

    The normal diurnal cortisol cycle has a peak in the morning, decreasing rapidly over the day, with low levels during the night, then rising rapidly again to the morning peak. A pattern of flatter daytime slopes has been associated with more rapid cancer progression in both animals and humans. We studied the relationship between the daytime slopes and other daytime cortisol responses to both pharmacological and psychosocial challenges of hypothalamic-pituitary-adrenal (HPA) axis function as well as DHEA in a sample of 99 women with metastatic breast cancer, in hopes of elucidating the dysregulatory process. We found that the different components of HPA regulation: the daytime cortisol slope, the rise in cortisol from waking to 30 min later, and cortisol response to various challenges, including dexamethasone (DEX) suppression, corticotrophin releasing factor (CRF) activation, and the Trier Social Stress Task, were at best modestly associated. Escape from suppression stimulated by 1mg of DEX administered the night before was moderately but significantly associated with flatter daytime cortisol slopes (r=0.28 to .30 at different times of the post DEX administration day, all p<.01). Daytime cortisol slopes were also moderately but significant associated with the rise in cortisol from waking to 30 min after awakening (r=.29, p=.004, N=96), but not with waking cortisol level (r=-0.13, p=.19). However, we could not detect any association between daytime cortisol slope and activation of cortisol secretion by either CRF infusion or the Trier Social Stress Task. The CRF activation test (following 1.5mg of DEX to assure that the effect was due to exogenous CRF) produced ACTH levels that were correlated (r=0.66, p<.0001, N=74) with serum cortisol levels, indicating adrenal responsiveness to ACTH stimulation. Daytime cortisol slopes were significantly correlated with the slope of DHEA (r=.21, p=.04, N=95). Our general findings suggest that flatter daytime cortisol slopes among

  6. Are Cardiac Autonomic Nervous System Activity and Perceived Stress Related to Functional Somatic Symptoms in Adolescents? The TRAILS Study

    PubMed Central

    Janssens, Karin A. M.; Riese, Harriëtte; Van Roon, Arie M.; Hunfeld, Joke A. M.; Groot, Paul F. C.; Oldehinkel, Albertine J.; Rosmalen, Judith G. M.

    2016-01-01

    Objective Stressors have been related to medically insufficiently explained or functional somatic symptoms (FSS). However, the underlying mechanism of this association is largely unclear. In the current study, we examined whether FSS are associated with different perceived stress and cardiac autonomic nervous system (ANS) levels during a standardized stressful situation, and whether these associations are symptom-specific. Methods We examined 715 adolescents (16.1 years, 51.3% girls) from the Dutch cohort study Tracking Adolescents’ Individual Lives Sample during the Groningen Social Stress Test (GSST). FSS were assessed by the Youth Self-Report, and clustered into a cluster of overtiredness, dizziness and musculoskeletal pain and a cluster of headache and gastrointestinal symptoms. Perceived stress levels (i.e. unpleasantness and arousal) were assessed by the Self-Assessment Manikin, and cardiac ANS activity by assessing heart rate variability (HRV-HF) and pre-ejection period (PEP). Perceived stress and cardiac ANS levels before, during, and after the GSST were studied as well as cardiac ANS reactivity. Linear regression analyses were used to examine the associations. Results Perceived arousal levels during (beta = 0.09, p = 0.04) and after (beta = 0.07, p = 0.047) the GSST, and perceived unpleasantness levels before (beta = 0.07, p = 0.048) and during (beta = 0.12, p = 0.001) the GSST were related to FSS during the past couple of months. The association between perceived stress and FSS was stronger for the FSS cluster of overtiredness, dizziness and musculoskeletal pain than for the cluster of headache and gastrointestinal symptoms. Neither ANS activity levels before, during, and after the GSST, nor maximal HF-HRV and PEP reactivity were related to FSS. Conclusions This study suggests that perceived stress levels during social stress are related to FSS, whereas cardiac ANS activity and reactivity are not related to FSS. PMID:27089394

  7. Novel metastasis-related gene CIM functions in the regulation of multiple cellular stress-response pathways.

    PubMed

    Yanagisawa, Kiyoshi; Konishi, Hiroyuki; Arima, Chinatsu; Tomida, Shuta; Takeuchi, Toshiyuki; Shimada, Yukako; Yatabe, Yasushi; Mitsudomi, Tetsuya; Osada, Hirotaka; Takahashi, Takashi

    2010-12-01

    Various stresses of the tumor microenvironment produced by insufficient nutrients, pH, and oxygen can contribute to the generation of altered metabolic and proliferative states that promote the survival of metastatic cells. Among many cellular stress-response pathways activated under such conditions are the hypoxia-inducible factor (HIF) pathway and the unfolded protein response (UPR), which is elicited as a response to endoplasmic reticulum (ER) stress. In this study, we report the identification of a novel cancer invasion and metastasis-related gene (hereafter referred to as CIM, also called ERLEC1), which influences both of these stress-response pathways to promote metastasis. CIM was identified by comparing the gene expression profile of a highly metastatic human lung cancer cell line with its weakly metastatic parental clone. We showed that CIM is critical for metastatic properties in this system. Proteomic approaches combined with bioinformatic analyses revealed that CIM has multifaceted roles in controlling the response to hypoxia and ER stress. Specifically, CIM sequestered OS-9 from the HIF-1α complex and PHD2, permitting HIF-1α accumulation by preventing its degradation. Ectopic expression of CIM in lung cancer cells increased their tolerance to hypoxia. CIM also modulated UPR through interaction with the key ER stress protein BiP, influencing cell proliferation under ER stress conditions. Our findings shed light on how tolerance to multiple cellular stresses at a metastatic site can be evoked by an integrated mechanism involving CIM, which can function to coordinate those responses in a manner that promotes metastatic cell survival. PMID:21118962

  8. PULMONARY FUNCTION IN NORMAL HUMANS WITH EXERCISE AND TEMPERATURE-HUMIDITY STRESS

    EPA Science Inventory

    Fifty-eight normal young male human subjects were exposed for 4 h to comfortable conditions or to heat stress conditions with or without exercise. Heat stress produced significant changes in forced vital capacity, and possibly significant interactions were observed in peak expira...

  9. Acute restraint stress enhances hippocampal endocannabinoid function via glucocorticoid receptor activation.

    PubMed

    Wang, Meina; Hill, Matthew N; Zhang, Longhua; Gorzalka, Boris B; Hillard, Cecilia J; Alger, Bradley E

    2012-01-01

    Exposure to behavioural stress normally triggers a complex, multilevel response of the hypothalamic-pituitary-adrenal (HPA) axis that helps maintain homeostatic balance. Although the endocannabinoid (eCB) system (ECS) is sensitive to chronic stress, few studies have directly addressed its response to acute stress. Here we show that acute restraint stress enhances eCB-dependent modulation of GABA release measured by whole-cell voltage clamp of inhibitory postsynaptic currents (IPSCs) in rat hippocampal CA1 pyramidal cells in vitro. Both Ca(2+)-dependent, eCB-mediated depolarization-induced suppression of inhibition (DSI), and muscarinic cholinergic receptor (mAChR)-mediated eCB mobilization are enhanced following acute stress exposure. DSI enhancement is dependent on the activation of glucocorticoid receptors (GRs) and is mimicked by both in vivo and in vitro corticosterone treatment. This effect does not appear to involve cyclooxygenase-2 (COX-2), an enzyme that can degrade eCBs; however, treatment of hippocampal slices with the L-type calcium (Ca(2+)) channel inhibitor, nifedipine, reverses while an agonist of these channels mimics the effect of in vivo stress. Finally, we find that acute stress produces a delayed (by 30 min) increase in the hippocampal content of 2-arachidonoylglycerol, the eCB responsible for DSI. These results support the hypothesis that the ECS is a biochemical effector of glucocorticoids in the brain, linking stress with changes in synaptic strength. PMID:21890595

  10. AtHSPR may function in salt-induced cell death and ER stress in Arabidopsis.

    PubMed

    Yang, Tao; Zhang, Peng; Wang, Chongying

    2016-07-01

    Salt stress is a harmful and global abiotic stress to plants and has an adverse effect on all physiological processes of plants. Recently, we cloned and identified a novel AtHSPR (Arabidopsis thaliana Heat Shock Protein Related), which encodes a nuclear-localized protein with ATPase activity, participates in salt and drought tolerance in Arabidopsis. Transcript profiling analysis revealed a differential expression of genes involved in accumulation of reactive oxygen species (ROS), abscisic acid (ABA) signaling, stress response and photosynthesis between athspr mutant and WT under salt stress. Here, we provide further analysis of the data showing the regulation of salt-induced cell death and endoplasmic reticulum (ER) stress response in Arabidopsis and propose a hypothetical model for the role of AtHSPR in the regulation of the salt tolerance in Arabidopsis. PMID:27302034

  11. Analysis of surface cracks at hole by a 3-D weight function method with stresses from finite element method

    NASA Technical Reports Server (NTRS)

    Zhao, W.; Newman, J. C., Jr.; Sutton, M. A.; Shivakumar, K. N.; Wu, X. R.

    1995-01-01

    Parallel with the work in Part-1, stress intensity factors for semi-elliptical surface cracks emanating from a circular hole are determined. The 3-D weight function method with the 3D finite element solutions for the uncracked stress distribution as in Part-1 is used for the analysis. Two different loading conditions, i.e. remote tension and wedge loading, are considered for a wide range in geometrical parameters. Both single and double surface cracks are studied and compared with other solutions available in the literature. Typical crack opening displacements are also provided.

  12. Morphological and functional manifestations of rat adrenal-cortex response to sodium bromide administration under hypodynamic stress

    NASA Technical Reports Server (NTRS)

    Kirichek, L. T.; Zholudeva, V. I.

    1979-01-01

    Functional and morphological manifestations of adrenal cortex response to hypodynamia (2-hr immobilization on an operating table) under the influence of bromine preparations were studied. The sodium bromide was administered intraperitoneally in 100, 250, and 500 mg/kg doses once and repeatedly during ten days. The adrenal gland was evaluated functionally by ascorbic acid and cholesterol content and morphologically by coloring it with hematoxylin-eosin and Sudans for lipid revealing at freezing. Results are displayed in two tables and microphotographs. They are summarized as follows: the bromine weakens the functional state of the adrenal cortex in intact rats, causing changes similar to those under stress. During immobilization combined with preliminary bromine administration, a less pronounced stress reaction is noticeable.

  13. Therapeutic effects of curcumin on the functional disturbances and oxidative stress induced by renal ischemia/reperfusion in rats

    PubMed Central

    Najafi, Houshang; Changizi Ashtiyani, Saeed; Sayedzadeh, Sayed Abolhasan; Mohamadi yarijani, Zeynab; Fakhri, Sajad

    2015-01-01

    Objective: Curcumin has anti-inflammatory and antioxidative properties. The objective of this study was to investigate the therapeutic effects of curcumin on functional disturbances, oxidative stress, and leukocyte infiltration induced by renal ischemia/reperfusion (I/R). Materials and Methods: Animals were randomly divided into 9 groups. The groups with 24-h reperfusion consisted of sham-24h, I/R-24h, and three I/R groups treated with curcumin at 10, 20, or 30 mg kg-1, i.p. after the ischemic period. The 72-h reperfusion groups also included Sham-72h, I/R-72h, I/R treated with curcumin at single dose of 20 mg kg-1, i.p., and I/R group which received three doses of curcumin at 20 mg kg-1, i.p., consecutively. Renal functional injury was assessed by measuring serum creatinine and urea-nitrogen concentrations. Oxidative stress was evaluated by assessment tissue malondialdehyde (MDA) and the ferric reducing/antioxidant power (FRAP) levels. Moreover, renal tissue leukocyte infiltration was measured by histopathology examination. Results: Ischemia/reperfusion resulted in a significant increase in serum concentration of creatinine, urea-nitrogen, tissue MDA level, and leukocytes infiltration as well as reduced FRAP level. Treatment with curcumin in 24-h reperfusion groups could only lead to a significant change in the levels of MDA and FRAP. However, in 72-h reperfusion groups, curcumin was able to correct all functional disturbances, oxidative stress, and leukocytes infiltration with more effectiveness in groups that received three doses of curcumin. Conclusion: The administration of curcumin during 72-h reperfusion following 30 minutes of ischemia can decrease renal oxidative stress and leukocytes infiltration as well as improve kidney function. However, during first 24-h reperfusion, curcumin only decreased oxidative stress. PMID:26693415

  14. Effect of uric acid on mitochondrial function and oxidative stress in hepatocytes.

    PubMed

    Yang, Y; Zhou, Y; Cheng, S; Sun, J L; Yao, H; Ma, L

    2016-01-01

    Here, we investigated the effect of uric acid (UA) on hepatocyte