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Sample records for hybrid stress general

  1. New Variational Formulations of Hybrid Stress Elements

    Science.gov (United States)

    Pian, T. H. H.; Sumihara, K.; Kang, D.

    1984-01-01

    In the variational formulations of finite elements by the Hu-Washizu and Hellinger-Reissner principles the stress equilibrium condition is maintained by the inclusion of internal displacements which function as the Lagrange multipliers for the constraints. These versions permit the use of natural coordinates and the relaxation of the equilibrium conditions and render considerable improvements in the assumed stress hybrid elements. These include the derivation of invariant hybrid elements which possess the ideal qualities such as minimum sensitivity to geometric distortions, minimum number of independent stress parameters, rank sufficient, and ability to represent constant strain states and bending moments. Another application is the formulation of semiLoof thin shell elements which can yield excellent results for many severe test cases because the rigid body nodes, the momentless membrane strains, and the inextensional bending modes are all represented.

  2. General linear dynamics - quantum, classical or hybrid

    CERN Document Server

    Elze, H-T; Vallone, F

    2011-01-01

    We describe our recent proposal of a path integral formulation of classical Hamiltonian dynamics. Which leads us here to a new attempt at hybrid dynamics, which concerns the direct coupling of classical and quantum mechanical degrees of freedom. This is of practical as well as of foundational interest and no fully satisfactory solution of this problem has been established to date. Related aspects will be observed in a general linear ensemble theory, which comprises classical and quantum dynamics in the form of Liouville and von Neumann equations, respectively, as special cases. Considering the simplest object characterized by a two-dimensional state-space, we illustrate how quantum mechanics is special in several respects among possible linear generalizations.

  3. Alternative ways for formulation of hybrid stress elements

    Science.gov (United States)

    Pian, T. H. H.; Chen, D.-P.

    1982-01-01

    An element stiffness matrix can be derived by the conventional potential energy principle and, indirectly, also by generalized variational principles, such as the Hu-Washizu principle and the Hellinger-Reissner principle. The present investigation has the objective to show an approach which is concerned with the formulation of incompatible elements for solid continuum and for plate bending problems by the Hellinger-Reissner principle. It is found that the resulting scheme is equivalent to that considered by Tong (1982) for the construction of hybrid stress elements. In Tong's scheme the inversion of a large flexibility matrix can be avoided. It is concluded that the introduction of additional internal displacement modes in mixed finite element formulations by the Hellinger-Reissner principle and the Hu-Washizu principle can lead to element stiffness matrices which are equivalent to the assumed stress hybrid method.

  4. THE STRESS SUBSPACE OF HYBRID STRESS ELEMENT AND THE DIAGONALIZATION METHOD FOR FLEXIBILITY MATRIX H

    Institute of Scientific and Technical Information of China (English)

    张灿辉; 冯伟; 黄黔

    2002-01-01

    The following is proved: 1 ) The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular fiexibility matrix; 2) The equivalent assumed stress modes lead to the identical hybrid element. The Hilbert stress subspace of the assumed stress modes is established. So, it is easy to derive the equivalent orthogonal normal stress modes by Schmidt 's method. Because of the resulting diagonal fiexibility matrix, the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency is improved greatly. The numerical examples show that the method is effective.

  5. Towards a General Theory of Stochastic Hybrid Systems

    OpenAIRE

    Bujorianu, L.M.; Lygeros, J.; Bujorianu, M. C.

    2008-01-01

    In this paper we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Markov strings are strong Markov processes with the cadlag property. We then show how a very general class of stochastic hybrid processes can be embedded in the framework of Markov strings. This class,...

  6. General Stress Responses in the Honey Bee

    Science.gov (United States)

    Even, Naïla; Devaud, Jean-Marc; Barron, Andrew B.

    2012-01-01

    The biological concept of stress originated in mammals, where a “General Adaptation Syndrome” describes a set of common integrated physiological responses to diverse noxious agents. Physiological mechanisms of stress in mammals have been extensively investigated through diverse behavioral and physiological studies. One of the main elements of the stress response pathway is the endocrine hypothalamo-pituitary-adrenal (HPA) axis, which underlies the “fight-or-flight” response via a hormonal cascade of catecholamines and corticoid hormones. Physiological responses to stress have been studied more recently in insects: they involve biogenic amines (octopamine, dopamine), neuropeptides (allatostatin, corazonin) and metabolic hormones (adipokinetic hormone, diuretic hormone). Here, we review elements of the physiological stress response that are or may be specific to honey bees, given the economical and ecological impact of this species. This review proposes a hypothetical integrated honey bee stress pathway somewhat analogous to the mammalian HPA, involving the brain and, particularly, the neurohemal organ corpora cardiaca and peripheral targets, including energy storage organs (fat body and crop). We discuss how this system can organize rapid coordinated changes in metabolic activity and arousal, in response to adverse environmental stimuli. We highlight physiological elements of the general stress responses that are specific to honey bees, and the areas in which we lack information to stimulate more research into how this fascinating and vital insect responds to stress. PMID:26466739

  7. Hybrid Dislocated Control and General Hybrid Projective Dislocated Synchronization for Memristor Chaotic Oscillator System

    Directory of Open Access Journals (Sweden)

    Junwei Sun

    2014-01-01

    Full Text Available Some important dynamical properties of the memristor chaotic oscillator system have been studied in the paper. A novel hybrid dislocated control method and a general hybrid projective dislocated synchronization scheme have been realized for memristor chaotic oscillator system. The paper firstly presents hybrid dislocated control method for stabilizing chaos to the unstable equilibrium point. Based on the Lyapunov stability theorem, general hybrid projective dislocated synchronization has been studied for the drive memristor chaotic oscillator system and the same response memristor chaotic oscillator system. For the different dimensions, the memristor chaotic oscillator system and the other chaotic system have realized general hybrid projective dislocated synchronization. Numerical simulations are given to show the effectiveness of these methods.

  8. Hybrid breakdown weakens under thermal stress in population crosses of the copepod Tigriopus californicus.

    Science.gov (United States)

    Willett, Christopher S

    2012-01-01

    The outcome of hybridization can be impacted by environmental conditions, which themselves can contribute to reproductive isolation between taxa. In crosses of genetically divergent populations, hybridization can have both negative and positive impacts on fitness, the balance between which might be tipped by changes in the environment. Genetically divergent populations of the intertidal copepod Tigriopus californicus have been shown to differ in thermal tolerance at high temperatures along a latitudinal gradient. In this study, a series of crosses were made between pairs of genetically divergent populations of T. californicus, and the thermal tolerance of these hybrids was tested. In most cases, the first-generation hybrids had relatively high thermal tolerance and the second-generation hybrids were not generally reduced below the less-tolerant parental population for high temperature tolerance. This pattern contrasts with previous studies from crosses of genetically divergent populations of this copepod, which often shows hybrid breakdown in these second-generation hybrids for other measures of fitness. These results suggest that high temperature stress could either increase the positive impacts of hybridization or decrease the negative impacts of hybridization resulting in lowered hybrid breakdown in these population crosses.

  9. A hybrid-stress element based on Hamilton principle

    Science.gov (United States)

    Cen, Song; Zhang, Tao; Li, Chen-Feng; Fu, Xiang-Rong; Long, Yu-Qiu

    2010-08-01

    A novel hybrid-stress finite element method is proposed for constructing simple 4-node quadrilateral plane elements, and the new element is denoted as HH4-3 β here. Firstly, the theoretical basis of the traditional hybrid-stress elements, i.e., the Hellinger-Reissner variational principle, is replaced by the Hamilton variational principle, in which the number of the stress variables is reduced from 3 to 2. Secondly, three stress parameters and corresponding trial functions are introduced into the system equations. Thirdly, the displacement fields of the conventional bilinear isoparametric element are employed in the new models. Finally, from the stationary condition, the stress parameters can be expressed in terms of the displacement parameters, and thus the new element stiffness matrices can be obtained. Since the required number of stress variables in the Hamilton variational principle is less than that in the Hellinger-Reissner variational principle, and no additional incompatible displacement modes are considered, the new hybrid-stress element is simpler than the traditional ones. Furthermore, in order to improve the accuracy of the stress solutions, two enhanced post-processing schemes are also proposed for element HH4-3 β. Numerical examples show that the proposed model exhibits great improvements in both displacement and stress solutions, implying that the proposed technique is an effective way for developing simple finite element models with high performance.

  10. Generalized rough sets hybrid structure and applications

    CERN Document Server

    Mukherjee, Anjan

    2015-01-01

    The book introduces the concept of “generalized interval valued intuitionistic fuzzy soft sets”. It presents the basic properties of these sets and also, investigates an application of generalized interval valued intuitionistic fuzzy soft sets in decision making with respect to interval of degree of preference. The concept of “interval valued intuitionistic fuzzy soft rough sets” is discussed and interval valued intuitionistic fuzzy soft rough set based multi criteria group decision making scheme is presented, which refines the primary evaluation of the whole expert group and enables us to select the optimal object in a most reliable manner. The book also details concept of interval valued intuitionistic fuzzy sets of type 2. It presents the basic properties of these sets. The book also introduces the concept of “interval valued intuitionistic fuzzy soft topological space (IVIFS topological space)” together with intuitionistic fuzzy soft open sets (IVIFS open sets) and intuitionistic fuzzy soft cl...

  11. General motors front wheel drive 2-mode hybrid transmission

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, James [General Motors Corp., Pontiac, MI (United States). New Transmission Products Group.; Holmes, Alan G. [General Motors Corp., Pontiac, MI (United States). Powertrain Hybrid Architecture

    2009-07-01

    General Motors now expands the application of two-mode hybrid technology to front wheel drive vehicles with the development of a hybrid electric transmission packaged into essentially the same space as a conventional automatic transmission for front wheel drive. This was accomplished using a space-efficient arrangement based on two planetary gear sets and electric motor-generators with large internal diameters. A combination of damper and hydraulically-controlled clutch allow comfortable shutdown and restarting of large-displacement engines in front wheel drive vehicles. The hybrid system delivers electric low-speed urban driving, two continuously variable ranges of transmission speed ratios, four fixed transmission speed ratios, electric acceleration boosting, and regenerative braking. In the first vehicle application, the two-mode hybrid helps to reduce vehicle fuel consumption by approximately one-third. (orig.)

  12. A hybrid-stress solid-shell element for non-linear analysis of piezoelectric structures

    Institute of Scientific and Technical Information of China (English)

    SZE; K; Y

    2009-01-01

    This paper presents eight-node solid-shell elements for geometric non-linear analyze of piezoelectric structures. To subdue shear, trapezoidal and thickness locking, the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed. With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement, an extended Hellinger-Reissner functional can be derived. By choosing the assumed generalized stresses similar to the assumed stresses of a previous solid ele- ment, a hybrid-stress solid-shell element is formulated. The presented finite shell element is able to model arbitrary curved shell structures. Non-linear numerical examples demonstrate the ability of the proposed model to analyze nonlinear piezoelectric devices.

  13. Towards a General Theory of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Lygeros, J.; Bujorianu, M.C.

    2008-01-01

    In this paper we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Mark

  14. Toward a General Theory of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Lygeros, J.; Blom, H.A.P.; Lygeros, J.

    2006-01-01

    In this chapter we set up a mathematical structure, called Markov string, to obtaining a very general class of models for stochastic hybrid systems. Markov Strings are, in fact, a class of Markov processes, obtained by a mixing mechanism of stochastic processes, introduced by Meyer. We prove that Ma

  15. STUDY ON STRESS CONCENTRATIONS IN AN INTRAPLY HYBRID COMPOSITE SHEET

    Institute of Scientific and Technical Information of China (English)

    曾庆敦; 黄小清; 林雪慧

    2001-01-01

    A reasonably, simply and accurately modified shear-lag model was proposed.Based on the model, the stress redistributions due to the failure of some fibers in an intraply hybrid composite under tension were analyzed. The results show that the present calculating stress concentration factors very coincide with Fukuda and Chou' s results, thus verifying the reasonableness and correctness of the present model and methods.

  16. Generalization of Dielectric-Dependent Hybrid Functionals to Finite Systems

    Science.gov (United States)

    Brawand, Nicholas P.; Vörös, Márton; Govoni, Marco; Galli, Giulia

    2016-10-01

    The accurate prediction of electronic and optical properties of molecules and solids is a persistent challenge for methods based on density functional theory. We propose a generalization of dielectric-dependent hybrid functionals to finite systems where the definition of the mixing fraction of exact and semilocal exchange is physically motivated, nonempirical, and system dependent. The proposed functional yields ionization potentials, and fundamental and optical gaps of many, diverse molecular systems in excellent agreement with experiments, including organic and inorganic molecules and semiconducting nanocrystals. We further demonstrate that this hybrid functional gives the correct alignment between energy levels of the exemplary TTF-TCNQ donor-acceptor system.

  17. Higher-order hybrid stress triangular Mindlin plate element

    Science.gov (United States)

    Li, Tan; Ma, Xu; Xili, Jing; Chen, Wanji

    2016-12-01

    A 6-node triangular hybrid stress element is presented for Mindlin plate in this paper. The proposed element, denoted by TH6-27β, can pass both the zero shear stress patch test and the non-zero constant shear stress enhanced patch test and, it can be employed to analyze very thin plate. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is used successfully to derive the displacement interpolation along each side of the element. According to the equilibrium equations, an appropriate stress approximation is rationally obtained. The assumed stress field is modified by using 27β instead of 15β to improve the accuracy. Numerical results show that the element is free of shear locking, and reliable for thick and thin plates. Moreover, it has no spurious zero energy modes and with geometric invariance (coordinate invariance, node sequencing independence).

  18. Multiple-time-stepping generalized hybrid Monte Carlo methods

    Energy Technology Data Exchange (ETDEWEB)

    Escribano, Bruno, E-mail: bescribano@bcamath.org [BCAM—Basque Center for Applied Mathematics, E-48009 Bilbao (Spain); Akhmatskaya, Elena [BCAM—Basque Center for Applied Mathematics, E-48009 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao (Spain); Reich, Sebastian [Universität Potsdam, Institut für Mathematik, D-14469 Potsdam (Germany); Azpiroz, Jon M. [Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) and Donostia International Physics Center (DIPC), P.K. 1072, Donostia (Spain)

    2015-01-01

    Performance of the generalized shadow hybrid Monte Carlo (GSHMC) method [1], which proved to be superior in sampling efficiency over its predecessors [2–4], molecular dynamics and hybrid Monte Carlo, can be further improved by combining it with multi-time-stepping (MTS) and mollification of slow forces. We demonstrate that the comparatively simple modifications of the method not only lead to better performance of GSHMC itself but also allow for beating the best performed methods, which use the similar force splitting schemes. In addition we show that the same ideas can be successfully applied to the conventional generalized hybrid Monte Carlo method (GHMC). The resulting methods, MTS-GHMC and MTS-GSHMC, provide accurate reproduction of thermodynamic and dynamical properties, exact temperature control during simulation and computational robustness and efficiency. MTS-GHMC uses a generalized momentum update to achieve weak stochastic stabilization to the molecular dynamics (MD) integrator. MTS-GSHMC adds the use of a shadow (modified) Hamiltonian to filter the MD trajectories in the HMC scheme. We introduce a new shadow Hamiltonian formulation adapted to force-splitting methods. The use of such Hamiltonians improves the acceptance rate of trajectories and has a strong impact on the sampling efficiency of the method. Both methods were implemented in the open-source MD package ProtoMol and were tested on a water and a protein systems. Results were compared to those obtained using a Langevin Molly (LM) method [5] on the same systems. The test results demonstrate the superiority of the new methods over LM in terms of stability, accuracy and sampling efficiency. This suggests that putting the MTS approach in the framework of hybrid Monte Carlo and using the natural stochasticity offered by the generalized hybrid Monte Carlo lead to improving stability of MTS and allow for achieving larger step sizes in the simulation of complex systems.

  19. Stress test: identifying crowding stress-tolerant hybrids in processing sweet corn

    Science.gov (United States)

    Improvement in tolerance to intense competition at high plant populations (i.e. crowding stress) is a major genetic driver of corn yield gain the last half-century. Recent research found differences in crowding stress tolerance among a few modern processing sweet corn hybrids; however, a larger asse...

  20. Hybrid dislocated control and general hybrid projective dislocated synchronization for the modified Lue chaotic system

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teacher' s College, Hubei 442000 (China)], E-mail: yuhuaxu2004@163.com; Zhou Wuneng [College of Information Science and Technology, Donghua University, Shanghai 201620 (China)], E-mail: wnzhou@163.com; Fang Jianan [College of Information Science and Technology, Donghua University, Shanghai 201620 (China)

    2009-11-15

    This paper introduces a modified Lue chaotic system, and some basic dynamical properties are studied. Based on these properties, we present hybrid dislocated control method for stabilizing chaos to unstable equilibrium and limit cycle. In addition, based on the Lyapunov stability theorem, general hybrid projective dislocated synchronization (GHPDS) is proposed, which includes complete dislocated synchronization, dislocated anti-synchronization and projective dislocated synchronization as its special item. The drive and response systems discussed in this paper can be strictly different dynamical systems (including different dimensional systems). As examples, the modified Lue chaotic system, Chen chaotic system and hyperchaotic Chen system are discussed. Numerical simulations are given to show the effectiveness of these methods.

  1. DEFORMATION RIGIDITY OF ASSUMED STRESS MODES IN HYBRID ELEMENTS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Can-hui; HUANG Qian; FENG Wei

    2006-01-01

    The new methods to determine the zero-energy deformation modes in the hybrid elements and the zero-energy stress modes in their assumed stress fields are presented by the natural deformation modes of the elements. And the formula of the additional element deformation rigidity due to additional mode into the assumed stress field is derived.Based on, it is concluded in theory that the zero-energy stress mode cannot suppress the zero-energy deformation modes but increase the extra rigidity to the nonzero-energy deformation modes of the element instead. So they should not be employed to assume the stress field. In addition, the parasitic stress modes will produce the spurious parasitic energy and result the element behaving over rigidity. Thus, they should not be used into the assumed stress field even though they can suppress the zero-energy deformation modes of the element. The numerical examples show the performance of the elements including the zero-energy stress modes or the parasitic stress modes.

  2. Hybrid-source impedance network and its generalized cascading concepts

    DEFF Research Database (Denmark)

    Li, Ding; Gao, Feng; Loh, Poh Chiang;

    2009-01-01

    . It is anticipated that these concepts and their formed inverters can find applications in photovoltaic and other renewable systems, which in turn motivate the investigation initiated here on two-level and three-level generalized cascading concepts. In addition to their theoretical performance merits, practical......Hybrid-source impedance networks have attracted attention among researchers because of their flexibility in performing buck-boost energy conversion. To date, three distinct types of impedance networks can be summarized for implementing voltage-type inverters, with another three types summarized...

  3. Tensile stress-strain behavior of hybrid composite laminates

    Science.gov (United States)

    Kennedy, J. M.

    1983-01-01

    A study was made of the stress-strain response of several hybrid laminates, and the damage was correlated with nonlinear stress-strain response and ultimate strength. The fibers used in the laminates were graphite, S-glass, and Kevlar. Some laminates with graphite fibers had perforated Mylar film between plies, which lowered the interlaminar bond strength. The laminate configurations were chosen to be like those of buffer strips in large panels and fracture coupons. Longitudinal and transverse specimens were loaded in tension to failure. Some specimens were radiographed to reveal damage due to edge effects. Stress-strain response is discussed in terms of damage shown by the radiographs. Ultimate strengths are compared with simple failure criteria, one of which account for damage.

  4. Metabolic and Phenotypic Responses of Greenhouse-Grown Maize Hybrids to Experimentally Controlled Drought Stress

    Institute of Scientific and Technical Information of China (English)

    Sandra Witt; Luis Galici; Jan Lisec; Jill Cairns; Axel Tiessen; Jose Luis Araus; Natalia Palacios-Rojas; Alisdair R.Fernie

    2012-01-01

    Adaptation to abiotic stresses like drought is an important acquirement of agriculturally relevant crops like maize.Development of enhanced drought tolerance in crops grown in climatic zones where drought is a very dominant stress factor therefore plays an essential role in plant breeding.Previous studies demonstrated that corn yield potential and enhanced stress tolerance are associated traits.In this study,we analyzed six different maize hybrids for their ability to deal with drought stress in a greenhouse experiment.We were able to combine data from morphophysiological parameters measured under well-watered conditions and under water restriction with metabolic data from different organs.These different organs possessed distinct metabolite compositions,with the leaf blade displaying the most considerable metabolome changes following water deficiency.Whilst we could show a general increase in metabolite levels under drought stress,including changes in amino acids,sugars,sugar alcohols,and intermediates of the TCA cycle,these changes were not differential between maize hybrids that had previously been designated based on field trial data as either drought-tolerant or susceptible.The fact that data described here resulted from a greenhouse experiment with rather different growth conditions compared to natural ones in the field may explain why tolerance groups could not be confirmed in this study.We were,however,able to highlight several metabolites that displayed conserved responses to drought as well as metabolites whose levels correlated well with certain physiological traits.

  5. The novel generating algorithm and properties of hybrid-P-ary generalized bridge functions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, we develop novel non-sine functions, named hybrid-P-ary generalized bridge functions, based on the copy and shift methods. The generating algorithm of hybrid-P-ary generalized bridge functions is introduced based on the hybrid-P-ary generalized Walsh function's copy algorithm. The main property, product property, is also discussed. This function may be viewed as the generalization of the theory of bridge functions. And a lot of non-sine orthogonal functions are the special subset of these novel functions. The hybrid-P-ary generalized bridge functions can be used to search many unknown non-sine functions by defining different parameters.

  6. A general purpose characterization system for rooftop hybrid microconcentrators

    Science.gov (United States)

    Middleton, Robert; Jones, Christopher; Thomsen, Elizabeth; Diez, Vicente Munoz; Harvey, J.; Everett, Vernie; Blakers, Andrew

    2014-09-01

    A versatile characterization system for hybrid thermal and photovoltaic solar receivers is presented and demonstrated. The characterization of the thermal loss and effective area of a novel hybrid receiver is presented.

  7. Psychological stress and multimorbidity in general practice

    DEFF Research Database (Denmark)

    Prior, Anders

    2017-01-01

    Background The number of persons living with multiple chronic conditions (multimorbidity) is rising owing to prolonged life and improved medical treatment. In this context, attention to mental health is essential; psychiatric illness has been associated with impaired quality of chronic care...... and poor prognosis of physical diseases, including increased mortality. However, little is known on the physical consequences of sub‐threshold psychological stress, which is more common than psychiatric disorders in the background population and is highly prevalent in persons with multimorbidity...... embrace poor mental health below the threshold for psychiatric disorders. More research on interventions targeting stress and multimorbidity are warranted....

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

    Science.gov (United States)

    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…

  9. Special hybrid stress element for stress analyses around circular cutouts in laminated composites

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A 3-dimensional hybrid stress element with a traction-free cylindrical surface based on amodified complementary energy principle has been derived for efficient and accurate analysis of stressconcentration around circular cutouts in thin to thick laminated composites. New expressions of sixstress components are developed by using three stress-functions in cylindrical co-ordinates, so that thehomogeneous equilibrium equations, the interlayer surface transverse-stresses and the traction-freeboundary condition on the cylindrical surface are satisfied exactly, while the interelement traction conti-nuity has been relaxed via the Lagrange multiplier method. Transverse-shear deformation effects areincorporated in each layer with displacement continuity enforced along interlayer surface. Selected ex-amples are used to demonstrate the efficiency and accuracy of the present special element.

  10. Generalized tetany: an unusual complication during dobutamine stress echocardiography.

    Science.gov (United States)

    Abbas, Amr E; Loftis, Rochelle; Lester, Steven J; Crawford, Michael B; Appleton, Christopher P

    2002-11-01

    Dobutamine stress echocardiography is a frequently used noninvasive method for the evaluation of inducible myocardial ischemia, myocardial viability, and preoperative cardiac risk. Although its clinical safety has been validated, side effects and complications especially with the coadministration of atropine can occur. We report a case of generalized tetany in a 49-year-old woman undergoing dobutamine stress echocardiography.

  11. A generalized hybrid transfinite element computational approach for nonlinear/linear unified thermal/structural analysis

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    The present paper describes the development of a new hybrid computational approach for applicability for nonlinear/linear thermal structural analysis. The proposed transfinite element approach is a hybrid scheme as it combines the modeling versatility of contemporary finite elements in conjunction with transform methods and the classical Bubnov-Galerkin schemes. Applicability of the proposed formulations for nonlinear analysis is also developed. Several test cases are presented to include nonlinear/linear unified thermal-stress and thermal-stress wave propagations. Comparative results validate the fundamental capablities of the proposed hybrid transfinite element methodology.

  12. Growth and Physiological Response of Jatropha Interspecific Hybrid (Jatropha curcas x J. integerrima under Salt Stress

    Directory of Open Access Journals (Sweden)

    Dhimas Handhi Putranto

    2014-01-01

    Full Text Available Interspecific hybrid of Jatropha curcas x J. integerrima is expected to answer the low oil yield problem of Jatropha (Jatropha curcas L.. However, as a novel invention, research concerning on Jatropha interspecific hybrid is still limited especially in the aspect of its adaptability to unfavorable environment such as salt stress condition. It is interesting to know how Jatropha interspecific hybrid responses to salt stress condition due to the moderate salt tolerance ability of its mother plant (J. curcas L.. The objectives of this study were to compare the growth and physiological response of interspecific hybrid and non-hybrid Jatropha under salt stress. Three varieties of both interspecific hybrid and non-hybrid Jatropha seedling were exposed with 3 levels of sodium chloride treatment in Hoagland media solution which are 2.0 (control, 8.0, and 16.0 dS m-1 for 7 weeks. The parameters measured include plant height, number of leaves, shoot dry weight, specific leaf area, chlorophyll content (SPAD Index, leaf water potential, and leaf solute concentration. V2 (interspecific hybrid showed the highest potential as moderate salt tolerant variety among experimental Jatropha varieties due to its increasing trend of leaf number, dry weight, and total leaf area at moderate salinity level   (8 dS m-1. KUBP 35 and KUBP 40 showed the best growth performance under salt stress among experimental Jatropha varieties, but its potential to be moderate salt tolerant variety was still lower than V2 variety. The solute concentration, osmotic potential, and turgor potential of both interspecific hybrid (V2 and non-hybrid variety (KUBP 35 and KUBP 40 showed an increasing pattern which could be implied as an adaptive response to salt stress. This study has showed that Jatropha interspecific hybrid might have an adaptive physiological response to salt stress and could be considered as potential moderate salt tolerant variety under salt stress.

  13. [A hybrid volume rendering method using general hardware].

    Science.gov (United States)

    Li, Bin; Tian, Lianfang; Chen, Ping; Mao, Zongyuan

    2008-06-01

    In order to improve the effect and efficiency of the reconstructed image after hybrid volume rendering of different kinds of volume data from medical sequential slices or polygonal models, we propose a hybrid volume rendering method based on Shear-Warp with economical hardware. First, the hybrid volume data are pre-processed by Z-Buffer method and RLE (Run-Length Encoded) data structure. Then, during the process of compositing intermediate image, a resampling method based on the dual-interpolation and the intermediate slice interpolation methods is used to improve the efficiency and the effect. Finally, the reconstructed image is rendered by the texture-mapping technology of OpenGL. Experiments demonstrate the good performance of the proposed method.

  14. The relationship between acculturative stress and eating disorder symptoms: is it unique from general life stress?

    Science.gov (United States)

    Kroon Van Diest, Ashley M; Tartakovsky, Margarita; Stachon, Caitlin; Pettit, Jeremy W; Perez, Marisol

    2014-06-01

    The purpose of the current study was to expand upon the literature examining the relationship between acculturative stress and eating disorder symptoms among different ethnic groups. Specifically, acculturative stress was explored as a moderator of the relationship between body dissatisfaction and eating disorder symptoms among ethnic minority women. Additionally, the distinction between acculturative stress and general life stress in predicting eating disorder symptoms was assessed. Participants consisted of 247 undergraduate women, all of whom were members of an ethnic minority group including African Americans, Asian Americans, and Latinas. Acculturative stress was found to moderate the relationship between body dissatisfaction and eating disorder symptoms, but only among African American women. Acculturative stress was also found to significantly predict bulimic symptoms above and beyond general life stress among African American, Asian American, and Latina women.

  15. Identification of calcium stress induced genes in amaranth leaves through suppression subtractive hybridization.

    Science.gov (United States)

    Aguilar-Hernández, Hugo S; Santos, Leticia; León-Galván, Fabiola; Barrera-Pacheco, Alberto; Espitia-Rangel, Eduardo; De León-Rodríguez, Antonio; Guevara-González, Ramón G; Barba de la Rosa, Ana P

    2011-11-15

    Calcium (Ca(2+)) is a critical ion for the growth and development of plants and plays an important role in signal transduction pathways in response to biotic and abiotic stresses. We investigated the Ca(2+) stress responsive-genes in amaranth leaves by using the suppression subtractive hybridization technique. Screening of the libraries generated 420 up-regulated transcripts and 199 down-regulated transcripts. The differentially expressed transcripts were associated with general stress response, transcription factors, gene regulation, signal transduction, and some other with unknown function. Selected genes were used to study their differential regulation by sqRT-PCR. Among the up-regulated transcripts, a fragment containing the motif of C3HC4-type RING-Zinc family was further characterized. The ORF of amaranth zinc finger protein (AhZnf) has a closer relationship with its ortholog from Ricinus communis while is distantly related to the Arabidopsis thaliana C3HC4-type ortholog. We have identified a novel putative zinc finger protein along with other novel proteins such as the wall associated kinase, phosphoinositide binding protein, and rhomboid protease involved in response to Ca(2+) stress in amaranth leaves.

  16. Special purpose hybrid transfinite elements and unified computational methodology for accurately predicting thermoelastic stress waves

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    This paper represents an attempt to apply extensions of a hybrid transfinite element computational approach for accurately predicting thermoelastic stress waves. The applicability of the present formulations for capturing the thermal stress waves induced by boundary heating for the well known Danilovskaya problems is demonstrated. A unique feature of the proposed formulations for applicability to the Danilovskaya problem of thermal stress waves in elastic solids lies in the hybrid nature of the unified formulations and the development of special purpose transfinite elements in conjunction with the classical Galerkin techniques and transformation concepts. Numerical test cases validate the applicability and superior capability to capture the thermal stress waves induced due to boundary heating.

  17. Principle Generalized Net Model of a Human Stress Reaction

    Directory of Open Access Journals (Sweden)

    Anthony Shannon

    2008-04-01

    Full Text Available The present study was aimed at investigating the mechanism of a human stress reaction by means of Generalized Nets (GNs. A principle GN-model of the main structures, organs and systems of the human body taking part in the acute and chronic reaction of the organism to a stress stimulus is generated. A possible application of the GN-model of the human stress reaction for testing the effect of known or newly synthesized pharmacological products as well as of food supplements is discussed.

  18. Hybridization of General Cargo Ships to meet the Required Energy Efficiency Design Index

    OpenAIRE

    Øverleir, Magnus Anders

    2015-01-01

    In this thesis a hybrid propulsion system is proposed for a general cargo ship with the aim to meet the required Energy Efficiency Design Index (EEDI). The study has investigated how a hybrid propulsion system will influence the ship s EEDI value and fuel economy. The central problem is the coming challenge for the general cargo segment meeting the required efficiency value. Especially small vessels (3 000-15 000 DWT) with high speed will have troubles complying with the stricter regulations....

  19. Transgenerational stress memory is not a general response in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ales Pecinka

    Full Text Available Adverse conditions can trigger DNA damage as well as DNA repair responses in plants. A variety of stress factors are known to stimulate homologous recombination, the most accurate repair pathway, by increasing the concentration of necessary enzymatic components and the frequency of events. This effect has been reported to last into subsequent generations not exposed to the stress. To establish a basis for a genetic analysis of this transgenerational stress memory, a broad range of treatments was tested for quantitative effects on homologous recombination in the progeny. Several Arabidopsis lines, transgenic for well-established recombination traps, were exposed to 10 different physical and chemical stress treatments, and scored for the number of somatic homologous recombination (SHR events in the treated generation as well as in the two subsequent generations that were not treated. These numbers were related to the expression level of genes involved in homologous recombination and repair. SHR was enhanced after the majority of treatments, confirming previous data and adding new effective stress types, especially interference with chromatin. Compounds that directly modify DNA stimulated SHR to values exceeding previously described induction rates, concomitant with an induction of genes involved in SHR. In spite of the significant stimulation in the stressed generations, the two subsequent non-treated generations only showed a low and stochastic increase in SHR that did not correlate with the degree of stimulation in the parental plants. Transcripts coding for SHR enzymes generally returned to pre-treatment levels in the progeny. Thus, transgenerational effects on SHR frequency are not a general response to abiotic stress in Arabidopsis and may require special conditions.

  20. Evaluation of thermally induced non-Fourier stress wave disturbances via tailored hybrid transfinite element formulations

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1989-01-01

    Accurate solutions have been obtained for a class of non-Fourier models in dynamic thermoelasticity which are relevant to the understanding of thermally-induced stress wave disturbances. The method employs tailored hybrid formulations based on the transfinite element approach. The results show that significant thermal stresses may arise due to non-Fourier effects, especially when the speeds of propagation of the thermal and stress waves are equal.

  1. Generalized non-linear strength theory and transformed stress space

    Institute of Scientific and Technical Information of China (English)

    YAO Yangping; LU Dechun; ZHOU Annan; ZOU Bo

    2004-01-01

    Based on the test data of frictional materials and previous research achievements in this field, a generalized non-linear strength theory (GNST) is proposed. It describes non-linear strength properties on the π-plane and the meridian plane using a unified formula, and it includes almost all the present non-linear strength theories, which can be used in just one material. The shape of failure function of the GNST is a smooth curve between the SMP criterion and the Mises criterion on the π-plane, and an exponential curve on the meridian plane. Through the transformed stress space based on the GNST, the combination of the GNST and various constitutive models using p and q as stress parameters can be realized simply and rationally in three-dimensional stress state.

  2. Transcriptomic analysis of Crassostrea sikamea × Crassostrea angulata hybrids in response to low salinity stress

    Science.gov (United States)

    Yan, Lulu; Su, Jiaqi; Wang, Zhaoping; Yan, Xiwu; Yu, Ruihai; Ma, Peizhen; Li, Yangchun; Du, Junpeng

    2017-01-01

    Hybrid oysters often show heterosis in growth rate, weight, survival and adaptability to extremes of salinity. Oysters have also been used as model organisms to study the evolution of host-defense system. To gain comprehensive knowledge about various physiological processes in hybrid oysters under low salinity stress, we performed transcriptomic analysis of gill tissue of Crassostrea sikamea ♀ × Crassostrea angulata♂ hybrid using the deep-sequencing platform Illumina HiSeq. We exploited the high-throughput technique to delineate differentially expressed genes (DEGs) in oysters maintained in hypotonic conditions. A total of 199,391 high quality unigenes, with average length of 644 bp, were generated. Of these 35 and 31 genes showed up- and down-regulation, respectively. Functional categorization and pathway analysis of these DEGs revealed enrichment for immune mechanism, apoptosis, energy metabolism and osmoregulation under low salinity stress. The expression patterns of 41 DEGs in hybrids and their parental species were further analyzed by quantitative real-time PCR (qRT-PCR). This study will serve as a platform for subsequent gene expression analysis regarding environmental stress. Our findings will also provide valuable information about gene expression to better understand the immune mechanism, apoptosis, energy metabolism and osmoregulation in hybrid oysters under low salinity stress. PMID:28182701

  3. A STUDY OF THE INFLUENCE OF INTERFACIAL DAMAGE ON STRESS CONCENTRATIONS IN INTRAPLY HYBRID COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Zeng Qingdun; Lin Xuehui

    2001-01-01

    In the axial tensile failure process of intraply hybrid composites, the breakage of some fibers may lead to interfacial damage, thus directly influencing the local stress concentrations near the sites of breakage. A modified shear-lag model, in which the interfacial damage is considered, is proposed. Based on the model, the influence of interfacial shear strength on the stress concentrations and the lengths of interfacial damage zone is first studied. The present results also provide an important theoretical basis for investigating the failure mechanism and hybrid effects for such kind of composites.

  4. Uniform convergence and a posteriori error estimation for assumed stress hybrid finite element methods

    CERN Document Server

    Yu, Guozhu; Carstensen, Carsten

    2011-01-01

    Assumed stress hybrid methods are known to improve the performance of standard displacement-based finite elements and are widely used in computational mechanics. The methods are based on the Hellinger-Reissner variational principle for the displacement and stress variables. This work analyzes two existing 4-node hybrid stress quadrilateral elements due to Pian and Sumihara [Int. J. Numer. Meth. Engng, 1984] and due to Xie and Zhou [Int. J. Numer. Meth. Engng, 2004], which behave robustly in numerical benchmark tests. For the finite elements, the isoparametric bilinear interpolation is used for the displacement approximation, while different piecewise-independent 5-parameter modes are employed for the stress approximation. We show that the two schemes are free from Poisson-locking, in the sense that the error bound in the a priori estimate is independent of the relevant Lame constant $\\lambda$. We also establish the equivalence of the methods to two assumed enhanced strain schemes. Finally, we derive reliable ...

  5. Inter-laminar shear stress in hybrid CFRP/austenitic steel

    Directory of Open Access Journals (Sweden)

    J. Lopes

    2015-01-01

    Full Text Available Bolted joints are the most common solution for joining composite components in aerospace structures. Critical structures such as wing to fuselage joints, or flight control surface fittings use bolted joining techniques. Recent research concluded that higher bearing strengths in composite bolted joints can be achieved by a CFRP/ Titanium hybrid lay-up in the vicinity of the bolted joint. The high costs of titanium motivate a similar research with the more cost competitive austenitic steel. An experimental program was performed in order to compare the apparent inter-laminar shear stress (ILSS of a CFRP reference beam with the ILSS of hybrid CFRP/Steel beams utilizing different surface treatments in the metallic ply. The apparent ILSS was determined by short beam test, a three-point bending test. Finite element models using cohesive elements in the CFRP/Steel interface were built to simulate the short beam test in the reference beam and in the highest interlaminar shear stress hybrid beam. The main parameters for a FEM simulation of inter laminar shear are the cohesive elements damage model and appropriate value for the critical energy release rate. The results show that hybrid CFRP/Steel have a maximum ILSS very similar to the ILSS of the reference beam. Hybrid CFRP/Steel is a competitive solution when compared with the reference beam ILSS. FEM models were able to predict the maximum ILSS in each type of beam.

  6. Stress-strength reliability for general bivariate distributions

    Directory of Open Access Journals (Sweden)

    Alaa H. Abdel-Hamid

    2016-10-01

    Full Text Available An expression for the stress-strength reliability R=P(X1general bivariate distribution. Such distribution includes bivariate compound Weibull, bivariate compound Gompertz, bivariate compound Pareto, among others. In the parametric case, the maximum likelihood estimates of the parameters and reliability function R are obtained. In the non-parametric case, point and interval estimates of R are developed using Govindarajulu's asymptotic distribution-free method when X1 and X2 are dependent. An example is given when the population distribution is bivariate compound Weibull. Simulation is performed, based on different sample sizes to study the performance of estimates.

  7. Residual stress and electromagnetic characteristics in loop type frequency selective surface embedded hybrid structures

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Mi; Seo, Yun Seok; Chun, Heoung Jae [Yonsei University, Seoul (Korea, Republic of); Hong, Ik Pyo [Kongju National University, Cheonan (Korea, Republic of); Park, Yong Bae [Ajoo University, Suwon (Korea, Republic of); Kim, Yoon Jae [Agency for defense development, Daejeon (Korea, Republic of)

    2015-01-15

    Residual stresses occur in frequency-selective surface (FSS)-embedded composite structures after co-curing due to differences between the coefficients of thermal expansion between composite skins and FSSs. Furthermore, the electromagnetic characteristics may be affected by the deformation of the FSS pattern by residual stresses. Therefore, we studied the changes in electromagnetic characteristics due to the deformation of FSS, using residual stresses to deform loop-type FSS-embedded hybrid composites. We considered the effects of loop-type FSS patterns of equal dimension as well as the stacking sequences of composite laminates on the electromagnetic characteristics of FSSs: Square loop, triangular loop and circular loop. The stacking sequences of composite laminates considered in this study were [0]{sub 8}, [0/90]{sub 4}, [+-45]{sub 4} and [0/+-45/90]{sub 2}. The FSS was located between composite laminates in the middle plane. To determine the residual stresses and deformations in the FSS embedded laminate structures, the thermal loading condition in the finite element analysis was induced by cooling the hybrid structures from 125 .deg. C to 20 .deg. C based on the cure cycle of the composite. Also, the electromagnetic reflection characteristics of the hybrid structures were predicted using deformed models by residual stresses, considering the effects of stacking sequence of composite laminates. The results showed that the maximum residual stresses and deformations were produced in the [0]{sub 8} composites with all three loop-types of FSS pattern. However, the maximum resonance frequency shifts occurred in the square and triangle loop-types with stacking sequence of [0]{sub 8} , while the maximum resonance frequency shift occurred in the circular loop-type with stacking sequence of [0/+-45/90]{sub 2}.

  8. Multistep Hybrid Iterations for Systems of Generalized Equilibria with Constraints of Several Problems

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available We first introduce and analyze one multistep iterative algorithm by hybrid shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: the generalized mixed equilibrium problem, finitely many variational inclusions, the minimization problem for a convex and continuously Fréchet differentiable functional, and the fixed-point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another multistep iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions.

  9. Three-dimensional hybrid-stress finite element analysis of composite laminates with cracks and cutouts

    Science.gov (United States)

    Wang, S. S.

    1985-01-01

    A three-dimensional hybrid-stress finite element analysis of composite laminates containing cutouts and cracks is presented. Fully three-dimensional, hexahedral isoparametric elements of the hybrid-stress model are formulated on the basis of the Hellinger-Reissner variational principle. Traction-free edges, cutouts, and crack surfaces are modeled by imposition of exact traction boundary conditions along element surfaces. Special boundary and surface elements are constructed by introducing proper constraints on assumed stress functions. The Lagrangian multiplier technique is used to enforce ply-interface continuity conditions in hybrid bimaterial composite elements for modeling the interface region in a composite laminate. Two examples are given to illustrate the capability of the present method of approach: (1) the well-known delamination problem in an angle-ply laminate, and (2) the important problem of a composite laminate containing a circular hole. Results are presented in detail for each case. Implications of interlaminar and intralaminar crack initiation, growth and fracture in composites containing cracks and cutouts are discussed.

  10. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions.

    Science.gov (United States)

    Jiménez, Juan de la Cruz; Cardoso, Juan A; Leiva, Luisa F; Gil, Juanita; Forero, Manuel G; Worthington, Margaret L; Miles, John W; Rao, Idupulapati M

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress.

  11. Non-destructive Phenotyping to Identify Brachiaria Hybrids Tolerant to Waterlogging Stress under Field Conditions

    Science.gov (United States)

    Jiménez, Juan de la Cruz; Cardoso, Juan A.; Leiva, Luisa F.; Gil, Juanita; Forero, Manuel G.; Worthington, Margaret L.; Miles, John W.; Rao, Idupulapati M.

    2017-01-01

    Brachiaria grasses are sown in tropical regions around the world, especially in the Neotropics, to improve livestock production. Waterlogging is a major constraint to the productivity and persistence of Brachiaria grasses during the rainy season. While some Brachiaria cultivars are moderately tolerant to seasonal waterlogging, none of the commercial cultivars combines superior yield potential and nutritional quality with a high level of waterlogging tolerance. The Brachiaria breeding program at the International Center for Tropical Agriculture, has been using recurrent selection for the past two decades to combine forage yield with resistance to biotic and abiotic stress factors. The main objective of this study was to test the suitability of normalized difference vegetation index (NDVI) and image-based phenotyping as non-destructive approaches to identify Brachiaria hybrids tolerant to waterlogging stress under field conditions. Nineteen promising hybrid selections from the breeding program and three commercial checks were evaluated for their tolerance to waterlogging under field conditions. The waterlogging treatment was imposed by applying and maintaining water to 3 cm above soil surface. Plant performance was determined non-destructively using proximal sensing and image-based phenotyping and also destructively via harvesting for comparison. Image analysis of projected green and dead areas, NDVI and shoot biomass were positively correlated (r ≥ 0.8). Our results indicate that image analysis and NDVI can serve as non-destructive screening approaches for the identification of Brachiaria hybrids tolerant to waterlogging stress. PMID:28243249

  12. A general model of distant hybridization reveals the conditions for extinction in Atlantic salmon and brown trout.

    Directory of Open Access Journals (Sweden)

    Claudio S Quilodrán

    Full Text Available Interspecific hybridization is common in nature but can be increased in frequency or even originated by human actions, such as species introduction or habitat modification, which may threaten species persistence. When hybridization occurs between distantly related species, referred to as "distant hybridization," the resulting hybrids are generally infertile or fertile but do not undergo chromosomal recombination during gametogenesis. Here, we present a model describing this frequent but poorly studied interspecific hybridization to assess its consequences on parental species and to anticipate the conditions under which they can reach extinction. Our general model fully incorporates three important processes: density-dependent competition, dominance/recessivity inheritance of traits and assortative mating. We demonstrate its use and flexibility by assessing population extinction risk between Atlantic salmon and brown trout in Norway, whose interbreeding has recently increased due to farmed fish releases into the wild. We identified the set of conditions under which hybridization may threaten salmonid species. Thanks to the flexibility of our model, we evaluated the effect of an additional risk factor, a parasitic disease, and showed that the cumulative effects dramatically increase the extinction risk. The consequences of distant hybridization are not genetically, but demographically mediated. Our general model is useful to better comprehend the evolution of such hybrid systems and we demonstrated its importance in the field of conservation biology to set up management recommendations when this increasingly frequent type of hybridization is in action.

  13. Low speed hybrid generalized predictive control of a gasoline-propelled car.

    Science.gov (United States)

    Romero, M; de Madrid, A P; Mañoso, C; Milanés, V

    2015-07-01

    Low-speed driving in traffic jams causes significant pollution and wasted time for commuters. Additionally, from the passengers׳ standpoint, this is an uncomfortable, stressful and tedious scene that is suitable to be automated. The highly nonlinear dynamics of car engines at low-speed turn its automation in a complex problem that still remains as unsolved. Considering the hybrid nature of the vehicle longitudinal control at low-speed, constantly switching between throttle and brake pedal actions, hybrid control is a good candidate to solve this problem. This work presents the analytical formulation of a hybrid predictive controller for automated low-speed driving. It takes advantage of valuable characteristics supplied by predictive control strategies both for compensating un-modeled dynamics and for keeping passengers security and comfort analytically by means of the treatment of constraints. The proposed controller was implemented in a gas-propelled vehicle to experimentally validate the adopted solution. To this end, different scenarios were analyzed varying road layouts and vehicle speeds within a private test track. The production vehicle is a commercial Citroën C3 Pluriel which has been modified to automatically act over its throttle and brake pedals.

  14. Residual Stress and Fatigue Strength of Hybrid Laser-MIG-Welded A7N01P-T4

    Science.gov (United States)

    Wang, Qiuying; Chen, Hui; Qiu, Peixian; Zhu, Zongtao

    2017-02-01

    A7N01P-T4 aluminum alloy is widely used in some important welded components of high-speed trains. The hybrid laser-metal inert gas (MIG) welding process was studied to solve problems associated with the MIG welding process, such as low welding efficiency, high residual stress and deformation, and serious loss of strength. A high-speed camera, a voltage and current collection system, and NI DAQ were used to acquire arc profiles, welding voltage, and welding current simultaneously. Thermal cycle tests were carried out. Residual stresses induced by the welding process and fatigue strength of the joint were investigated. Large-size fatigue specimens were used in fatigue tests. The results show that the energy of the hybrid welding process is focused, and the power density of hybrid welding process is intense. The heat input per unit of the hybrid welding process is only half of that of the MIG welding process. Compared with the MIG welded joint, the overall residual stress level of the hybrid-welded joint is lower. The peak longitudinal stress of the hybrid-welded joint is reduced by 20 pct. The fatigue strength of hybrid joints is 14 pct higher than that of MIG-welded joints. Narrow weld and HAZ, weak softening behavior, and low residual stress level are the causes of the improvement of fatigue strength.

  15. Residual Stress and Fatigue Strength of Hybrid Laser-MIG-Welded A7N01P-T4

    Science.gov (United States)

    Wang, Qiuying; Chen, Hui; Qiu, Peixian; Zhu, Zongtao

    2016-09-01

    A7N01P-T4 aluminum alloy is widely used in some important welded components of high-speed trains. The hybrid laser-metal inert gas (MIG) welding process was studied to solve problems associated with the MIG welding process, such as low welding efficiency, high residual stress and deformation, and serious loss of strength. A high-speed camera, a voltage and current collection system, and NI DAQ were used to acquire arc profiles, welding voltage, and welding current simultaneously. Thermal cycle tests were carried out. Residual stresses induced by the welding process and fatigue strength of the joint were investigated. Large-size fatigue specimens were used in fatigue tests. The results show that the energy of the hybrid welding process is focused, and the power density of hybrid welding process is intense. The heat input per unit of the hybrid welding process is only half of that of the MIG welding process. Compared with the MIG welded joint, the overall residual stress level of the hybrid-welded joint is lower. The peak longitudinal stress of the hybrid-welded joint is reduced by 20 pct. The fatigue strength of hybrid joints is 14 pct higher than that of MIG-welded joints. Narrow weld and HAZ, weak softening behavior, and low residual stress level are the causes of the improvement of fatigue strength.

  16. A general hybrid radiation transport scheme for star formation simulations on an adaptive grid

    CERN Document Server

    Klassen, Mikhail; Pudritz, Ralph E; Peters, Thomas; Banerjee, Robi; Buntemeyer, Lars

    2014-01-01

    Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodynamics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion (FLD) solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calc...

  17. Likelihood Inference under Generalized Hybrid Censoring Scheme with Comp eting Risks

    Institute of Scientific and Technical Information of China (English)

    MAO Song; SHI Yi-min

    2016-01-01

    Statistical inference is developed for the analysis of generalized type-II hybrid censoring data under exponential competing risks model. In order to solve the problem that approximate methods make unsatisfactory performances in the case of small sample size, we establish the exact conditional distributions of estimators for parameters by conditional moment generating function(CMGF). Furthermore, confidence intervals(CIs) are constructed by exact distributions, approximate distributions as well as bootstrap method respectively, and their performances are evaluated by Monte Carlo simulations. And finally, a real data set is analyzed to illustrate all the methods developed here.

  18. Stress-energy-momentum of affine-metric gravity generalized Komar superpotential

    CERN Document Server

    Giachetta, G

    1995-01-01

    In case of the Einstein's gravitation theory and its first order Palatini reformulation, the stress-energy-momentum of gravity has been proved to reduce to the Komar superpotential. We generalize this result to the affine-metric theory of gravity in case of general connections and arbitrary Lagrangian densities invariant under general covariant transformations. In this case, the stress-energy-momentum of gravity comes to the generalized Komar superpotential depending on a Lagrangian density in a precise way.

  19. Computer modeling for investigating the stress-strainstate of beams with hybrid reinforcement

    Directory of Open Access Journals (Sweden)

    Rakhmonov Ahmadzhon Dzhamoliddinovich

    2014-01-01

    Full Text Available In this article the operation of a continuous double-span beam with hybrid reinforcement, steel and composite reinforcement under the action of concentrated forces is considered. The nature of stress-strain state of structures is investigated with the help of computer modeling using a three-dimensional model. Five models of beams with different characteristics were studied. According to the results of numerical studies the data on the distribution of stresses and displacements in continuous beams was provided. The dependence of the stress-strain state on increasing the percentage of the top reinforcement (composite of fittings and change in the concrete class is determined and presented in the article. Currently, the interest in the use of composite reinforcement as a working reinforcement of concrete structures in Russia has increased significantly, which is reflected in the increase of the number of scientific and practical publications devoted to the study of the properties and use of composite materials in construction, as well as emerging draft documents for design of such structures. One of the proposals for basalt reinforcement application is to use it in bending elements with combined reinforcement. For theoretical justification of the proposed nature of reinforcement and improvement of the calculation method the authors conduct a study of stress-strain state of continuous beams with the use of modern computing systems. The software program LIRA is most often used compared to other programs representing strain-stress state analysis of concrete structures.

  20. The factors associated to psychosocial stress among general practitioners in Lithuania. Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Vanagas Giedrius

    2005-06-01

    Full Text Available Abstract Background There are number of studies showing that general practice is one of the most stressful workplace among health care workers. Since Baltic States regained independence in 1990, the reform of the health care system took place in which new role and more responsibilities were allocated to general practitioners' in Lithuania. This study aimed to explore the psychosocial stress level among Lithuanian general practitioner's and examine the relationship between psychosocial stress and work characteristics. Methods The cross-sectional study of 300 Lithuanian General practitioners. Psychosocial stress was investigated with a questionnaire based on the Reeder scale. Job demands were investigated with the R. Karasek scale. The analysis included descriptive statistics; interrelationship analysis between characteristics and multivariate logistic regression to estimate odds ratios for each of the independent variables in the model. Results Response rate 66% (N = 197. Our study highlighted highest prevalence of psychosocial stress among widowed, single and female general practitioners. Lowest prevalence of psychosocial stress was among males and older age general practitioners. Psychosocial stress occurs when job demands are high and job decision latitude is low (χ2 = 18,9; p Conclusion One half of respondents suffering from work related psychosocial stress. High psychological workload demands combined with low decision latitude has the greatest impact to stress caseness among GP's. High job demands, high patient load and young age of GP's can be assigned as significant predictors of psychosocial stress among GP's.

  1. Recovery from hybrid breakdown in a marine invertebrate is faster, stronger and more repeatable under environmental stress.

    Science.gov (United States)

    Hwang, A S; Pritchard, V L; Edmands, S

    2016-09-01

    Understanding how environmental stress alters the consequences of hybridization is important, because the rate of hybridization and the likelihood of hybrid speciation both appear elevated in harsh, disturbed or marginal habitats. We assessed fitness, morphometrics and molecular genetic composition over 14 generations of hybridization between two highly divergent populations of the marine copepod Tigriopus californicus. Replicated, experimental hybrid populations in both control and high-salinity conditions showed a decline in fitness, followed by a recovery. Recovery was faster in the salinity stress treatment, returning to parental levels up to two generations earlier than in the control. This recovery was stable in the high-salinity treatment, whereas in the control treatment, fitness dropped back below parental levels at the final time point. Recovery in the high-salinity treatment was also stronger in terms of competitive fitness and heat-shock tolerance. Finally, consequences of hybridization were more repeatable under salinity stress, where among-replicate variance for survivorship and molecular genetic composition was lower than in the control treatment. In a system with low effective population sizes (estimates ranged from 17 to 63), where genetic drift might be expected to be the predominate force, strong selection under harsh environmental conditions apparently promoted faster, stronger and more repeatable recovery from depressed hybrid fitness.

  2. Evaluation of a general hybrid RANS/LES model in smooth wall reattachment

    Science.gov (United States)

    Haering, Sigfried; Moser, Robert

    2016-11-01

    Hybrid RANS/LES modeling approaches often exhibit deficiencies when used for common problems of engineering interest containing flow features such as unsteady smooth-wall separation and reattachment with non-trivial domains and discretization. Often, problem specific modifications and tuning must be employed rendering these models ineffective as generally predictive tools. A new broadly applicable hybrid RANS/LES modeling approach that is being developed to specifically address challenges associated with complex geometries and flows is presented. In general, the approach seeks to a balance between theoretical and actual modeled turbulent kinetic energy provided information from the underlying turbulence model, the resolved turbulence, and the available resolution. Anisotropy in the grid and resolved field are directly integrated into this balance. Here, we examine model performance with the case of a wall-mounted smooth hump of Greenblatt et al.. Excellent agreement with experimental results is attained while significantly outperforming delayed detached eddy simulation (DDES) for nearly the same computational expense and without any problem-specific modifications.

  3. Exposed to events that never happen: Generalized unsafety, the default stress response, and prolonged autonomic activity.

    Science.gov (United States)

    Brosschot, Jos F; Verkuil, Bart; Thayer, Julian F

    2017-03-01

    Based on neurobiological and evolutionary arguments, the generalized unsafety theory of stress (GUTS) hypothesizes that the stress response is a default response, and that chronic stress responses are caused by generalized unsafety (GU), independent of stressors or their cognitive representation. Three highly prevalent conditions are particularly vulnerable to becoming 'compromised' in terms of GU, and carry considerable health risks: Thus, GUTS critically revises and expands stress theory, by focusing on safety instead of threat, and by including risk factors that have hitherto not been attributed to stress.

  4. On Hybrid and mixed finite element methods

    Science.gov (United States)

    Pian, T. H. H.

    1981-01-01

    Three versions of the assumed stress hybrid model in finite element methods and the corresponding variational principles for the formulation are presented. Examples of rank deficiency for stiffness matrices by the hybrid stress model are given and their corresponding kinematic deformation modes are identified. A discussion of the derivation of general semi-Loof elements for plates and shells by the hybrid stress method is given. It is shown that the equilibrium model by Fraeijs de Veubeke can be derived by the approach of the hybrid stress model as a special case of semi-Loof elements.

  5. A quadrilateral membrane hybrid stress element with drilling degrees of freedom

    Institute of Scientific and Technical Information of China (English)

    An-Ping Wang

    2012-01-01

    A new kind of quadrilateral assumed stress hybrid membrane element with drilling degrees of freedom and a traction-free inclined side has been developed based on an extended Hellinger-Reissner principle which is established by expanding the essential terms of the assumed stress field as polynomials in the natural coordinates of the element.The homogeneous equilibrium equations are imposed in a variational sense through the internal displacements which are also expanded in the natural coordinates,while the tractionfree conditions along the inclined side are satisfied exactly.The use of such special element in the finite element solution is shown to be highly accurate when only a very coarse element mesh is used for plates with V-shaped rounded notches or inclined sides.

  6. General engineering ethics and multiple stress of atomic energy engineering

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kunihiko [Shibaura Inst. of Tech., Tokyo (Japan)

    1999-08-01

    The factors, by which the modern engineering ethics has been profoundly affected, were classified to three categories, namely mental blow, the destruction of human function and environment damage. The role of atomic energy engineering in the ethic field has been shown in the first place. It is pointed out that it has brought about the mental blow by the elucidation of universal truth and discipline and the functional disorder by the power supply. However, the direct effect of radiation to the human kinds is only a part of the stresses comparing to the accumulation of the social stress which should be taken into account of by the possibility of disaster and the suspicion of the atomic energy politics. An increase in the multiple stresses as well as the restriction of criticism will place obstacles on the promotion of atomic energy. (author)

  7. Dual Stimuli-Activatable Oxidative Stress Amplifying Agent as a Hybrid Anticancer Prodrug.

    Science.gov (United States)

    Han, Eunji; Kwon, Byeongsu; Yoo, Donghyuck; Kang, Changsun; Khang, Gilson; Lee, Dongwon

    2017-04-19

    Compared to normal cells, cancer cells have a higher level of reactive oxygen species (ROS) due to aberrant metabolism and disruption of redox homeostasis which drive their proliferation and promote progression and metastasis of cancers. The altered redox balance and biological difference between normal cells and cancer cells provide a basis for the development of anticancer agents which are able to generate pharmacological ROS insults to kill cancer cells preferentially. In this study, we report a new hybrid anticancer drug, termed OSamp, which undergoes esterase- and acid-catalyzed hydrolysis to deplete antioxidant glutathione (GSH) and generate ROS, simultaneously. OSamp significantly elevated oxidative stress in cancer cells, leading to enhanced apoptotic cancer cell death through mitochondrial membrane disruption, cytochrome c release, activation of pro-caspase 3, and deactivation of STAT3 (signal transducer and activator of transcription-3). OSamp, administered intravenously, significantly suppressed the tumor growth in a mouse model of tumor xenografts without notable side effects. Oxidative stress amplifying OSamp holds tremendous potential as a new anticancer therapeutic and provides a new therapeutic paradigm which can be extended to development of hybrid anticancer drugs.

  8. Investigating the drought-stress response of hybrid poplar genotypes by metabolite profiling.

    Science.gov (United States)

    Barchet, Genoa L H; Dauwe, Rebecca; Guy, Robert D; Schroeder, William R; Soolanayakanahally, Raju Y; Campbell, Malcolm M; Mansfield, Shawn D

    2014-11-01

    Drought stress is perhaps the most commonly encountered abiotic stress plants experience in the natural environment, and it is one of the most important factors limiting plant productivity. Here, we employed untargeted metabolite profiling to examine four drought-stressed hybrid poplar (Populus spp.) genotypes for their metabolite content, using gas chromatography coupled to mass spectrometry. The primary objective of these analyses was to characterize the metabolite profile of poplar trees to assess relative drought resistance and to investigate the underlying biochemical mechanisms employed by the genotypes to combat drought. Metabolite profiling identified key metabolites that increased or decreased in relative abundance upon exposure to drought stress. Overall, amino acids, the antioxidant phenolic compounds catechin and kaempferol, as well as the osmolytes raffinose and galactinol exhibited increased abundance under drought stress, whereas metabolites involved in photorespiration, redox regulation and carbon fixation showed decreased abundance under drought stress. One clone in particular, Okanese, displayed unique responses to the imposed drought conditions. This clone was found to have higher leaf water potential, but lower growth rate relative to the other clones tested. Okanese also had lower accumulation of osmolytes such as raffinose, galactinol and proline, but higher overall levels of antioxidants such as catechin and dehydroascorbic acid. As such, it was proposed that osmotic adjustment as a mechanism for drought avoidance in this clone is not as well developed in comparison with the other clones investigated in this study, and that a possible alternative mechanism for the enhanced drought avoidance displayed by Okanese may be due to differential allocation of resources or better retention of water.

  9. A general hybrid radiation transport scheme for star formation simulations on an adaptive grid

    Energy Technology Data Exchange (ETDEWEB)

    Klassen, Mikhail; Pudritz, Ralph E. [Department of Physics and Astronomy, McMaster University 1280 Main Street W, Hamilton, ON L8S 4M1 (Canada); Kuiper, Rolf [Max Planck Institute for Astronomy Königstuhl 17, D-69117 Heidelberg (Germany); Peters, Thomas [Institut für Computergestützte Wissenschaften, Universität Zürich Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Banerjee, Robi; Buntemeyer, Lars, E-mail: klassm@mcmaster.ca [Hamburger Sternwarte, Universität Hamburg Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2014-12-10

    Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodyanmics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calculating gas and dust temperatures in the presence of multiple stellar sources. Our method enables radiation-hydrodynamic studies of young stellar objects, protostellar disks, and clustered star formation in magnetized, filamentary environments.

  10. A General Hybrid Radiation Transport Scheme for Star Formation Simulations on an Adaptive Grid

    Science.gov (United States)

    Klassen, Mikhail; Kuiper, Rolf; Pudritz, Ralph E.; Peters, Thomas; Banerjee, Robi; Buntemeyer, Lars

    2014-12-01

    Radiation feedback plays a crucial role in the process of star formation. In order to simulate the thermodynamic evolution of disks, filaments, and the molecular gas surrounding clusters of young stars, we require an efficient and accurate method for solving the radiation transfer problem. We describe the implementation of a hybrid radiation transport scheme in the adaptive grid-based FLASH general magnetohydrodyanmics code. The hybrid scheme splits the radiative transport problem into a raytracing step and a diffusion step. The raytracer captures the first absorption event, as stars irradiate their environments, while the evolution of the diffuse component of the radiation field is handled by a flux-limited diffusion solver. We demonstrate the accuracy of our method through a variety of benchmark tests including the irradiation of a static disk, subcritical and supercritical radiative shocks, and thermal energy equilibration. We also demonstrate the capability of our method for casting shadows and calculating gas and dust temperatures in the presence of multiple stellar sources. Our method enables radiation-hydrodynamic studies of young stellar objects, protostellar disks, and clustered star formation in magnetized, filamentary environments.

  11. Simulation of generalized hybrid model for solar and wind power generation

    Directory of Open Access Journals (Sweden)

    Vankadara Sampath kumar

    2015-03-01

    Full Text Available Due to urbanization, globalization and industrialization the demand for energy is rapidly increasing allows the world and India is not an exception. Out of all energies electrical energy is playing a major role in developed as well as developing countries. The energy is mostly produced by fossil fuels which are developing day his is to by day .they also produce lot of pollutants which totally damage the environment the alternative to this is to encourage renewable energy source. Now days the energy production at domestic level is becoming popular with the help of solar and wind energies . These technologies are widely used now days in the present paper an attempt has been made to simulate a generalized hybrid model including solar and wind.

  12. Fully implicit mixed-hybrid finite-element discretization for general purpose subsurface reservoir simulation

    Science.gov (United States)

    Abushaikha, Ahmad S.; Voskov, Denis V.; Tchelepi, Hamdi A.

    2017-10-01

    We present a new fully-implicit, mixed-hybrid, finite-element (MHFE) discretization scheme for general-purpose compositional reservoir simulation. The locally conservative scheme solves the coupled momentum and mass balance equations simultaneously, and the fluid system is modeled using a cubic equation-of-state. We introduce a new conservative flux approach for the mass balance equations for this fully-implicit approach. We discuss the nonlinear solution procedure for the proposed approach, and we present extensive numerical tests to demonstrate the convergence and accuracy of the MHFE method using tetrahedral elements. We also compare the method to other advanced discretization schemes for unstructured meshes and tensor permeability. Finally, we illustrate the applicability and robustness of the method for highly heterogeneous reservoirs with unstructured grids.

  13. General and hybrid correlation nuclear magnetic resonance analysis of phosphorus in Phytophthora palmivora.

    Science.gov (United States)

    Kirwan, Gemma M; Fernandez, David I; Niere, Julie O; Adams, Michael J

    2012-10-01

    Generalized two-dimensional (Gen2D) correlation analysis and hybrid correlation analysis have been applied to a series of dynamic (31)P nuclear magnetic resonance (NMR) spectra to monitor the in vivo metabolic changes of the plant pathogen Phytophthora palmivora in the presence and absence of phosphonate over an 18-h period. Results indicate that phosphonate exposure causes cleavage in organism polyphosphate chains as well as an increase in total sugar phosphates. In the presence of phosphonate, the NMR resonances attributed to terminal polyphosphate phosphorus reduced at a lower rate than those of middle polyphosphate phosphorus, indicating a change in average chain length and suggesting cleavage in the middle of the chain as well as at the ends. The correlation analysis techniques serve to identify and confirm spectral regions undergoing major change in the time-series data and facilitate the analysis of these dynamic changes.

  14. Exponential synchronization of general chaotic delayed neural networks via hybrid feedback

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper investigates the exponential synchronization problem of some chaotic delayed neural networks based on the proposed general neural network model, which is the interconnection of a linear delayed dynamic system and a bounded static nonlinear operator, and covers several well-known neural networks, such as Hopfield neural networks, cellular neural networks (CNNs), bidirectional associative memory (BAM) networks, recurrent multilayer perceptrons (RMLPs). By virtue of LyapunovKrasovskii stability theory and linear matrix inequality (LMI) technique, some exponential synchronization criteria are derived.Using the drive-response concept, hybrid feedback controllers are designed to synchronize two identical chaotic neural networks based on those synchronization criteria. Finally, detailed comparisons with existing results are made and numerical simulations are carried out to demonstrate the effectiveness of the established synchronization laws.

  15. ["Stress" ulcer--a problem of the general surgeon].

    Science.gov (United States)

    Danelisen, D; Zigić, B; Rac, S

    1982-01-01

    Contemporary way of living accompanied by everday frustrations, a frequent use of medicaments, an easy application of corticosteroids, complexity of an opeation, so as an increased incidence of polytraumas --those are the factors responsible for an increasing rate of stress ulcus. The rate of 54 verified stress ulcus in the period from 1969-1979 in Regional Medical Centre of Banja Luka, at Surgical Department, are very often indicative of this disease. Thirty eight operatively treated patients are indicative of severity of this disease. The authors are reporting their experiences in resolving this disease by method of vagotomy with partial gastrectomy in comparison to simple sutures of acutely developed ulcus in addition to PS vagotomy. Perforation, which has, usually, been bigger than the chronic ulcus, we had in 31 cases. If the reports of the world authors are reliable, perforation occurs in 5% of cases only, therefore it is clear how many such conditions has remained undetected or treated under various other "working" diagnoses: (DIC, consumer coagulopathy, fibrinolysis, etc.". The stress ulcus is the disease which is a danger to any patient at Surgical Department.

  16. The biomechanics of a validated finite element model of stress shielding in a novel hybrid total knee replacement.

    Science.gov (United States)

    Bougherara, H; Zdero, R; Mahboob, Z; Dubov, A; Shah, S; Schemitsch, E H

    2010-10-01

    This study proposes a novel hybrid total knee replacement (TKR) design to improve stress transfer to bone in the distal femur and, thereby, reduce stress shielding and consequent bone loss. Three-dimensional finite element (FE) models were developed for a standard and a hybrid TKR and validated experimentally. The Duracon knee system (Stryker Canada) was the standard TKR used for the FE models and for the experimental tests. The FE hybrid device was identical to the standard TKR, except that it had an interposing layer of carbon fibre-reinforced polyamide 12 lining the back of the metallic femoral component. A series of experimental surface strain measurements were then taken to validate the FE model of the standard TKR at 3000 N of axial compression and at 0 degreeof knee flexion. Comparison of surface strain values from FE analysis with experiments demonstrated good agreement, yielding a high Pearson correlation coefficient of R(2)= 0.94. Under a 3000N axial load and knee flexion angles simulating full stance (0O degree, heel strike (200 degrees, and toe off (600 degrees during normal walking gait, the FE model showed considerable changes in maximum Von Mises stress in the region most susceptible to stress shielding (i.e. the anterior region, just behind the flange of the femoral implant). Specifically, going from a standard to a hybrid TKR caused an increase in maximum stress of 87.4 per cent (O0 degree from 0.15 to 0.28 MPa), 68.3 per cent (200 degrees from 1.02 to 1.71 MPa), and 12.6 per cent (600 degrees from 2.96 to 3.33 MPa). This can potentially decrease stress shielding and subsequent bone loss and knee implant loosening. This is the first report to propose and biomechanically to assess a novel hybrid TKR design that uses a layer of carbon fibrereinforced polyamide 12 to reduce stress shielding.

  17. Occupational stress and coping resources in physiotherapists: a survey of physiotherapists in three general hospitals.

    Science.gov (United States)

    Santos, M C; Barros, L; Carolino, E

    2010-12-01

    To identify occupational stressors and coping resources in a group of physiotherapists, and to analyse interactions between subjective levels of stress, efficacy in stress resolution and coping resources used by these professionals. A sample of 55 physiotherapists working in three general hospitals in Portugal completed the Coping Resources Inventory for Stress, the Occupational Stressors Inventory and two subjective scales for stress and stress resolution. Most physiotherapists perceived that they were moderately stressed (19/55, 35%) or stressed (20/55, 36%) due to work, and reported that their efficacy in stress resolution was moderate (25/54, 46%) or efficient (23/54, 42%). Issues related to lack of professional autonomy, lack of organisation in the hierarchical command chain, lack of professional and social recognition, disorganisation in task distribution and interpersonal conflicts with superiors were identified as the main sources of stress. The most frequently used coping resources were social support, stress monitoring, physical health and structuring. Perceived efficacy in stress resolution was inversely related to perceived level of occupational stress (r=-0.61, P<0.01). Significant correlations were found between several coping resources and the perceived level of stress and efficacy in stress resolution. Associations between problem solving, cognitive restructuring and stress monitoring and both low levels of perceived stress and high levels of perceived efficacy were particularly strong. The importance of identifying stressors and coping resources related to physiotherapists' occupational stress, and the need for the development of specific training programmes to cope with stress are supported. Copyright © 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  18. Existence and stability, and discrete BB and rank conditions, for general mixed-hybrid finite elements in elasticity

    Science.gov (United States)

    Xue, W.-M.; Atluri, S. N.

    1985-01-01

    In this paper, all possible forms of mixed-hybrid finite element methods that are based on multi-field variational principles are examined as to the conditions for existence, stability, and uniqueness of their solutions. The reasons as to why certain 'simplified hybrid-mixed methods' in general, and the so-called 'simplified hybrid-displacement method' in particular (based on the so-called simplified variational principles), become unstable, are discussed. A comprehensive discussion of the 'discrete' BB-conditions, and the rank conditions, of the matrices arising in mixed-hybrid methods, is given. Some recent studies aimed at the assurance of such rank conditions, and the related problem of the avoidance of spurious kinematic modes, are presented.

  19. Hybrid Viscosity Approaches to General Systems of Variational Inequalities with Hierarchical Fixed Point Problem Constraints in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2014-01-01

    Full Text Available The purpose of this paper is to introduce and analyze hybrid viscosity methods for a general system of variational inequalities (GSVI with hierarchical fixed point problem constraint in the setting of real uniformly convex and 2-uniformly smooth Banach spaces. Here, the hybrid viscosity methods are based on Korpelevich’s extragradient method, viscosity approximation method, and hybrid steepest-descent method. We propose and consider hybrid implicit and explicit viscosity iterative algorithms for solving the GSVI with hierarchical fixed point problem constraint not only for a nonexpansive mapping but also for a countable family of nonexpansive mappings in X, respectively. We derive some strong convergence theorems under appropriate conditions. Our results extend, improve, supplement, and develop the recent results announced by many authors.

  20. Stress among general practitioners of Kwa-Dukuza, Kwa-Zulu Natal

    Directory of Open Access Journals (Sweden)

    Indiran Govender

    2009-04-01

    Full Text Available Background: Stress and burnout are prevalent among the caring professionals, including doctors and nurses. The work-related stress rate among the general working population is 18% whilst among doctors it is around 28%. Stress in general practitioners (GPs can result in multiple negative consequences. Detecting stress early may have positive outcomes for doctors, their families and the people they care for at their practice.Method: A cross-sectional, descriptive study using a self-administered, standardised questionnaire (12-item General Health Questionnaire [GHC] was performed on the 30 general practitioners in Kwa-Dukuza. Confidentiality and anonymity were maintained.Results: 26 of the 30 GPs (87% responded to the survey. 10 GPs (38% were stressed as per the GHQ, six of whom were severely stressed. 22 reported that they felt stressed at work (subjectively.Conclusion: The results indicated that stress among Kwa-Dukuza GPs is slightly higher (38% than found in other studies that indicate a prevalence of 28% among doctors.

  1. Work Related Stress, Burnout, Job Satisfaction and General Health of Nurses

    OpenAIRE

    Natasha Khamisa; Brian Oldenburg; Karl Peltzer; Dragan Ilic

    2015-01-01

    Gaps in research focusing on work related stress, burnout, job satisfaction and general health of nurses is evident within developing contexts like South Africa. This study identified the relationship between work related stress, burnout, job satisfaction and general health of nurses. A total of 1200 nurses from four hospitals were invited to participate in this cross-sectional study (75% response rate). Participants completed five questionnaires and multiple linear regression analysis was us...

  2. Internal stress distribution of X-ring using photoelastic experimental hybrid method

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Lim, Hyun Seok [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

    2014-05-15

    Sealing elements are essential parts of many machines, and are used to prevent the loss of a fluid or gas. When such fluids are not properly sealed, catastrophic failures may result. Many different types of rings have been developed to suit various industrial needs. Considerable research has been done on the O-ring. We analyze the internal stresses developed in an X-ring under a uniform squeeze rate of 20%, which is suitable for static applications, using a photoelastic experimental hybrid method. The internal pressures applied were 0.98, 1.96, 2.94, 3.92, 4.90, and 5.88 MPa. We show that sealing rings with X geometry have considerably higher internal stresses than O-ring seals. In addition, we demonstrate that after extrusion, for an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merge, thereby increasing the contact length of the upper side significantly. Extrusion in the X-ring occurred when the internal pressure was 4.90 MPa.

  3. Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

    2016-01-01

    induced residual stresses. It is also investigated whether the assumption of residual stresses up to yield strength magnitude are present in welded structures as stated in the design guidelines. The fatigue strength for welded joints is based on this assumption. The two welding methods investigated...... are hybrid laser-arc welding (HLAW) and submerged arc welding (SAW). Both welding methods are applied for a full penetration butt-weld of 10 mm thick plates made of thermomechanically hot-rolled, low-carbon, fine-grain S355ML grade steel used in offshore steel structures. The welding residual stress state...

  4. Arousal Predisposition as a Vulnerability Indicator for Psychosis: A General Population Online Stress Induction Study

    Directory of Open Access Journals (Sweden)

    Annika Clamor

    2015-01-01

    Full Text Available Explanatory models ascribe to arousability a central role for the development of psychotic symptoms. Thus, a disposition to hyperarousal (i.e., increased arousal predisposition (AP may serve as an underlying vulnerability indicator for psychosis by interacting with stressors to cause symptoms. In this case, AP, stress-response, and psychotic symptoms should be linked before the development of a diagnosable psychotic disorder. We conducted a cross-sectional online study in a population sample (N=104; Mage=27.7 years, SD=11.2, range 18–70. Participants rated their AP and subclinical psychotic symptoms. Participants reported their stress-levels before and after two stress inductions including an arithmetic and a social stressor. The participants with an increased AP generally felt more stressed. However, AP was not associated with the specific stress-response. As expected, positive psychotic symptoms were significantly associated with AP, but this was not mediated by general stress-levels. Its association to subtle, nonclinical psychotic symptoms supports our assumption that AP could be a vulnerability indicator for psychosis. The trait is easily accessible via a short self-report and could facilitate the identification of people at risk and be a promising target for early stress-management. Further research is needed to clarify its predictive value for stress-responses.

  5. Study to evaluate the effectiveness of stress management workshops on response to general and occupational measures of stress.

    Science.gov (United States)

    Heron, R J; McKeown, S; Tomenson, J A; Teasdale, E L

    1999-09-01

    This study was designed to evaluate the effectiveness of stress management training workshops within Zeneca Pharmaceuticals. The study was of cross-sectional design, comparing groups of workshop attendees and non-attendees. In addition, self-rated well-being scores of attendees were compared with results obtained pre-workshop and 2-3 months after the workshop. Employees participating in the study were drawn from the Manufacturing, Research and Development, Sales and Marketing sites of Zeneca Pharmaceuticals located in Cheshire, United Kingdom. Three hundred and ninety persons who had participated in stress management workshops since 1988 were matched for age, gender and department with an equal number of employees who had not attended stress management workshops. Outcome measures included self-rated well-being (as measured by the 30-question General Health Questionnaire), knowledge of company guidance on the management of stress in staff, and an assessment of coping strategies. Subjects who had not attended a stress management workshop were much more likely to have a poor understanding of the principles of management of stress in staff [odds ratio (OR) = 8.3; 95% confidence interval (CI) = 3.3-21.3] and more likely to have poor coping skills (OR = 2.8; CI = 1.3-6.1). However, mean scores for the two measures were similar in attendees and non-attendees. Self-rating of current well-being was strongly associated with the life-events score, but not related to workshop attendance. The study indicates that stress management training workshops reduce the prevalence of employees with a poor understanding of the principles of the management of stress in staff and with poor coping strategies. An improvement in the self-rated well-being observed shortly after the workshop was not sustained.

  6. Effects of Drought Stress on Vegetative and Reproductive Stages of Forage and Kernel Corn Hybrids

    Directory of Open Access Journals (Sweden)

    M Hajibabaei

    2016-10-01

    Full Text Available Introduction Maize is one of the most important cereals which its global production is severely affected by drought in many parts of the world. One of the best ways of water management on field is to choose the proper variety which could be chosen indirectly by the traits affecting the grain yield. Materials and Methods In order to study the effect of drought stress in vegetative and reproductive stages in 14 corn hybrids, an experiment was conducted at the experimental field of Seed and Plant Improvement Institute of Karaj, in 2009. The Research Station located in 50°, 55´ eastern latitude and 35°, 47´ northern longitude with 1254 height above mean sea level (AMSL. The soil texture of the location was loam-clay with pH= 7.5 and the Electrical Capacity (EC = 0.7 dsm-1. The experiment was carried out using split-plot in a randomized complete block design (RCBD with three replications. The main plots consisted of three levels of irrigation regimes (irrigation after 70, 100 and 130 mm cumulative evaporation from evaporation pan class A and sub-plots included 14 new corn hybrids Includes eleven new hybrids such as (K47/2-2-1-4-1-1-1×MO17، K3653/2×K19، KLM76004/3-2-1-1-1-1-1-1×K3545/6، K3653/2×MO17، K74/2-2-1-2-1-1-1-1×K3545/6، K47/3-1-2-7-1-1-1×MO17، K47/2-2-1-2-2-1-1-1×K3544/1، KLM76004/3-2-1-1-1-1-1-1×K3544/1، K47/2-2-1-2-1-1-1-1×K3544/1، KLM77029/8-1-2-3-2-3×MO17 and KLM76005/2-3-1-1-1-1×MO17 and three hybrid control (KSC704, KSC720, KSC700. Irrigation time was determined using daily evaporation rate of standard class A evaporation pan. To determine the volume of water per irrigation, a sample of each plot from depth of root development was prepared before irrigation. The samples were kept in oven 80°C for 24 hours. The weight of soil moisture content was calculated and the volume of water per irrigation was calculated using equations 1 and 2. 1: H = ρb (F.C - m D 2: V = H × A Where H is the water height in the

  7. Heightened reward learning under stress in generalized anxiety disorder: a predictor of depression resistance?

    Science.gov (United States)

    Morris, Bethany H; Rottenberg, Jonathan

    2015-02-01

    Stress-induced anhedonia is associated with depression vulnerability (Bogdan & Pizzagalli, 2006). We investigated stress-induced deficits in reward learning in a depression-vulnerable group with analogue generalized anxiety disorder (GAD, n = 34), and never-depressed healthy controls (n = 41). Utilizing a computerized signal detection task, reward learning was assessed under stressor and neutral conditions. Controls displayed intact reward learning in the neutral condition, and the expected stress-induced blunting. The GAD group as a whole also showed intact reward learning in the neutral condition. When GAD subjects were analyzed as a function of prior depression history, never-depressed GAD subjects showed heightened reward learning in the stressor condition. Better reward learning under stress among GAD subjects predicted lower depression symptoms 1 month later. Robust reward learning under stress may indicate depression resistance among anxious individuals.

  8. Identification and characterization of low temperature stress responsive genes in Poncirus trifoliata by suppression subtractive hybridization.

    Science.gov (United States)

    Peng, T; Zhu, X F; Fan, Q J; Sun, P P; Liu, J H

    2012-01-15

    Trifoliate orange (Poncirus trifoliata (L.) Raf.) is extremely cold hardy when fully acclimated, but knowledge relevant to the molecular events underlying the acclimation is still limited so far. In this study, forward (4 °C over 25 °C) and reverse (25 °C over 4 °C) suppression subtractive hybridization (SSH) libraries were constructed in order to identify the genes involved in cold acclimation in trifoliate orange. After reverse northern blotting analysis and sequencing, a total of 105 and 117 non-redundant differentially expressed sequence tags (ESTs) were obtained from the forward and reverse libraries, respectively. Blast2go analysis revealed that 91 ESTs, 31 from the forward library and 60 from the reverse library, displayed significant sequence homology to the genes with known or putative functions. They were categorized into various functional groups, including catalytic activity, binding protein, structural molecule, enzyme regulator, molecular transducer, electron carrier, and transport activity/transcription regulation. Expression analysis of the selected ESTs by reverse transcriptase polymerase chain reaction was consistent with the results of differential screening. In addition, time-course expression patterns of the genes further confirmed that they were responsive to low temperature treatment. Among the genes of known functions, many are related to maintenance of cell wall integrity, adjustment of osmotic potential and maintenance of reactive oxygen species homeostasis, implying that these physiological processes might be of paramount significance in rendering protective mechanisms against the low temperature stress. The data presented here gain an insight into the molecular changes underlying the cold acclimation of trifoliate orange, and the results can be of reference for unraveling candidate genes that hold great potential for genetic engineering in an effort to create novel germplasms with enhanced cold stress tolerance.

  9. Using the stress function in the flow of generalized Newtonian fluids through pipes and slits

    CERN Document Server

    Sochi, Taha

    2015-01-01

    We use a generic and general numerical method to obtain solutions for the flow of generalized Newtonian fluids through circular pipes and plane slits. The method, which is simple and robust can produce highly accurate solutions which virtually match any analytical solutions. The method is based on employing the stress, as a function of the pipe radius or slit thickness dimension, combined with the rate of strain function as represented by the fluid rheological constitutive relation that correlates the rate of strain to stress. Nine types of generalized Newtonian fluids are tested in this investigation and the solutions obtained from the generic method are compared to the analytical solutions which are obtained from the Weissenberg-Rabinowitsch-Mooney-Schofield method. Very good agreement was obtained in all the investigated cases. All the required quantities of the flow which include local viscosity, rate of strain, flow velocity profile and volumetric flow rate, as well as shear stress, can be obtained from ...

  10. Stress analysis and damage evaluation of flawed composite laminates by hybrid-numerical methods

    Science.gov (United States)

    Yang, Yii-Ching

    1992-01-01

    Structural components in flight vehicles is often inherited flaws, such as microcracks, voids, holes, and delamination. These defects will degrade structures the same as that due to damages in service, such as impact, corrosion, and erosion. It is very important to know how a structural component can be useful and survive after these flaws and damages. To understand the behavior and limitation of these structural components researchers usually do experimental tests or theoretical analyses on structures with simulated flaws. However, neither approach has been completely successful. As Durelli states that 'Seldom does one method give a complete solution, with the most efficiency'. Examples of this principle is seen in photomechanics which additional strain-gage testing can only average stresses at locations of high concentration. On the other hand, theoretical analyses including numerical analyses are implemented with simplified assumptions which may not reflect actual boundary conditions. Hybrid-Numerical methods which combine photomechanics and numerical analysis have been used to correct this inefficiency since 1950's. But its application is limited until 1970's when modern computer codes became available. In recent years, researchers have enhanced the data obtained from photoelasticity, laser speckle, holography and moire' interferometry for input of finite element analysis on metals. Nevertheless, there is only few of literature being done on composite laminates. Therefore, this research is dedicated to this highly anisotropic material.

  11. Crash simulation of hybrid structures considering the stress and strain rate dependent material behavior of thermoplastic materials

    Science.gov (United States)

    Hopmann, Ch.; Schöngart, M.; Weber, M.; Klein, J.

    2015-05-01

    Thermoplastic materials are more and more used as a light weight replacement for metal, especially in the automotive industry. Since these materials do not provide the mechanical properties, which are required to manufacture supporting elements like an auto body or a cross bearer, plastics are combined with metals in so called hybrid structures. Normally, the plastics components are joined to the metal structures using different technologies like welding or screwing. Very often, the hybrid structures are made of flat metal parts, which are stiffened by a reinforcement structure made of thermoplastic materials. The loads on these structures are very often impulsive, for example in the crash situation of an automobile. Due to the large stiffness variation of metal and thermoplastic materials, complex states of stress and very high local strain rates occur in the contact zone under impact conditions. Since the mechanical behavior of thermoplastic materials is highly dependent on these types of load, the crash failure of metal plastic hybrid parts is very complex. The problem is that the normally used strain rate dependent elastic/plastic material models are not capable to simulate the mechanical behavior of thermoplastic materials depended on the state of stress. As part of a research project, a method to simulate the mechanical behavior of hybrid structures under impact conditions is developed at the IKV. For this purpose, a specimen for the measurement of mechanical properties dependet on the state of stress and a method for the strain rate depended characterization of thermoplastic materials were developed. In the second step impact testing is performed. A hybrid structure made from a metal sheet and a reinforcement structure of a Polybutylenterephthalat Polycarbonate blend is tested under impact conditions. The measured stress and strain rate depended material data are used to simulate the mechanical behavior of the hybrid structure under highly dynamic load with

  12. Levels of Stress among General Practitioners, Students and Specialists In Pediatric Dentistry during Dental Treatment.

    Science.gov (United States)

    Davidovich, E; Pessov, Y; Baniel, A; Ram, D

    2015-01-01

    To assess self-reported stress during the performance of different procedures in pediatric dentistry, according to the professional experience of the dentists. During the years 2010 to 2011, an anonymous survey was administered by means of an internet link, and by distribution at professional meetings of dentists . No statistically significant differences in stress were reported for maxilla and mandibular procedures. Placement of a rubber dam was rated as the most stressful procedure among dental students. For general practitioners and specialists, injection of local anesthesia to an anxious child was the most stressful procedure, regardless of age, sex, or years of professional experience. A negative correlation was found between years of experience and level of stress for all the procedures surveyed, but not for the use of nitrous oxide. No differences were found between male and female dentists in stress scores for any of the procedures. Higher rates of stress during operative procedures were reported among dental students than among experienced dentists. Anxiety of the pediatric patients, but not the location of the procedure: maxillary or mandibular, affected the dentists' reported level of stress.

  13. Effects of Cold and Heat Stress on Egg Quality Traits of a Newly Developed Native Hybrid Layer

    Directory of Open Access Journals (Sweden)

    İsmail Durmuş

    2015-03-01

    Full Text Available ATAK-S is a newly developed native hybrid layer. Although the laying performance of this hybrid has been studied and determined, the performance response of the hybrid to different environmental temperature conditions is not known. This study was therefore undertaken to determine the effect of cold and heat stress on egg quality traits. Hens were divided into three different groups; control (20°C, low (12°C and high (32°C. A total of 360 hens, with 120 in each of the groups, were used in the study. Hens were held in three tier battery cages in an environmentally controlled poultry house. The study lasted for 3 weeks. No differences were found among different groups in terms of shape index, albumen height and Haugh unit of the egg quality traits. It was found that the differences among the heat groups in terms of egg shell breaking strength, egg weight, shell thickness and yolk colour were significant and the value of these traits decreased under the heat stress conditions, whereas they were not affected from the cold stress.

  14. Monotone Hybrid Projection Algorithms for an Infinitely Countable Family of Lipschitz Generalized Asymptotically Quasi-Nonexpansive Mappings

    Directory of Open Access Journals (Sweden)

    Watcharaporn Cholamjiak

    2009-01-01

    Full Text Available We prove a weak convergence theorem of the modified Mann iteration process for a uniformly Lipschitzian and generalized asymptotically quasi-nonexpansive mapping in a uniformly convex Banach space. We also introduce two kinds of new monotone hybrid methods and obtain strong convergence theorems for an infinitely countable family of uniformly Lipschitzian and generalized asymptotically quasi-nonexpansive mappings in a Hilbert space. The results improve and extend the corresponding ones announced by Kim and Xu (2006 and Nakajo and Takahashi (2003.

  15. Calculation of Cauchy stress tensor in molecular dynamics system with a generalized Irving-Kirkwood formulism

    CERN Document Server

    Yang, Jerry Zhijian

    2014-01-01

    Irving and Kirkwood formulism (IK formulism) provides a way to compute continuum mechanics quantities at certain location in terms of molecular variables. To make the approach more practical in computer simulation, Hardy proposed to use a spacial kernel function that couples continuum quantities with atomistic information. To reduce irrational fluctuations, Murdoch proposed to use a temporal kernel function to smooth the physical quantities obtained in Hardy's approach. In this paper, we generalize the original IK formulism to systematically incorporate both spacial and temporal average. The Cauchy stress tensor is derived in this generalized IK formulism (g-IK formulism). Analysis is given to illuminate the connection and difference between g-IK formulism and traditional temporal post-process approach. The relationship between Cauchy stress and first Piola-Kirchhoff stress is restudied in the framework of g-IK formulism. Numerical experiments using molecular dynamics are conducted to examine the analysis res...

  16. CLINICAL APPLICATION OF ACUPUNCTURE ON ALLEVIATION OF STRESS REACTION INDUCED BY TRACHEAL INTUBATION IN GENERAL ANESTHESIA

    Institute of Scientific and Technical Information of China (English)

    SHI Jin-hua

    2006-01-01

    By summarizing the formation of stress reaction induced by tracheal intubation and method of medicinal control, the recognition of Chinese medicine in treatment of cardiac arrhythmia and hypertension with acupuncture and the clinical application of acupuncture on stress reaction induced by tracheal intubation,it is concluded that the side effects of tracheal intubation are inevitable, even though there are many methods presented for the prevention and treatment for it. In recent years, the functions of acupuncture in anesthesia,especially in regulation of circulatory properties have been developed gradually and have been applied by many physicians in controlling the stress reaction induced by tracheal intubation in general anesthesia. Being a kind of dual-directional and positive regulation and stimulation, acupuncture provides definite and safe effects on controlling the stress reaction induced by tracheal intubation.

  17. Does Empathy Predict Instructional Assignment-Related Stress? A Study in Special and General Education Teachers

    Science.gov (United States)

    Platsidou, Maria; Agaliotis, Ioannis

    2017-01-01

    The role of empathy in the teaching profession has been vastly investigated in relation to its effect on students, but research on how teachers' empathy affects their own well-being at work is limited. This study investigated empathy and instructional assignment-related stress factors of primary school teachers serving in general or special…

  18. Does Empathy Predict Instructional Assignment-Related Stress? A Study in Special and General Education Teachers

    Science.gov (United States)

    Platsidou, Maria; Agaliotis, Ioannis

    2017-01-01

    The role of empathy in the teaching profession has been vastly investigated in relation to its effect on students, but research on how teachers' empathy affects their own well-being at work is limited. This study investigated empathy and instructional assignment-related stress factors of primary school teachers serving in general or special…

  19. Lagrangian viscoelastic flow computations using a generalized molecular stress function model

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.

    2002-01-01

    –Sawyers fluid to a fluid described by a generalized molecular stress function (MSF) model allowing the use of dissipative convective constraint release in the constitutive equation. The convergence of the method is demonstrated on the axis-symmetric problem of the inflation of a polymeric membrane only...

  20. A ROBUST PHASE-ONLY DIRECT DATA DOMAIN ALGORITHM BASED ON GENERALIZED RAYLEIGH QUOTIENT OPTIMIZATION USING HYBRID GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Shao Wei; Qian Zuping; Yuan Feng

    2007-01-01

    A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on generalized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency and computational speed are improved via the hybrid GA composed of standard GA and Nelder-Mead simplex algorithms. First, the objective function, with a form of generalized Rayleigh quotient, is derived via the standard D3LS algorithm. It is then taken as a fitness function and the unknown phases of all adaptive weights are taken as decision variables.Then, the nonlinear optimization is performed via the hybrid GA to obtain the optimized solution of phase-only adaptive weights. As a phase-only adaptive algorithm, the proposed algorithm is simpler than conventional algorithms when it comes to hardware implementation. Moreover, it processes only a single snapshot data as opposed to forming sample covariance matrix and operating matrix inversion. Simulation results show that the proposed algorithm has a good signal recovery and interferences nulling performance, which are superior to that of the phase-only D3LS algorithm based on standard GA.

  1. General job stress: a unidimensional measure and its non-linear relations with outcome variables.

    Science.gov (United States)

    Yankelevich, Maya; Broadfoot, Alison; Gillespie, Jennifer Z; Gillespie, Michael A; Guidroz, Ashley

    2012-04-01

    This article aims to examine the non-linear relations between a general measure of job stress [Stress in General (SIG)] and two outcome variables: intentions to quit and job satisfaction. In so doing, we also re-examine the factor structure of the SIG and determine that, as a two-factor scale, it obscures non-linear relations with outcomes. Thus, in this research, we not only test for non-linear relations between stress and outcome variables but also present an updated version of the SIG scale. Using two distinct samples of working adults (sample 1, N = 589; sample 2, N = 4322), results indicate that a more parsimonious eight-item SIG has better model-data fit than the 15-item two-factor SIG and that the eight-item SIG has non-linear relations with job satisfaction and intentions to quit. Specifically, the revised SIG has an inverted curvilinear J-shaped relation with job satisfaction such that job satisfaction drops precipitously after a certain level of stress; the SIG has a J-shaped curvilinear relation with intentions to quit such that turnover intentions increase exponentially after a certain level of stress.

  2. Numerical Analysis of Welding Residual Stress and Distortion in Laser+GMAW Hybrid Welding of Aluminum Alloy T-Joint

    Institute of Scientific and Technical Information of China (English)

    Guoxiang XU; Chuansong WU; Xuezhou MA; Xuyou WANG

    2013-01-01

    A 3-D finite element model is developed to predict the temperature field and thermally induced residual stress and distortion in laser+GMAW hybrid welding of 6061-T6 aluminum alloy T-joint.And the characteristics of residual stress distribution and deformation are numerically investigated.In the simulation,the heat source model takes into account the effect of joint geometric shape and welding torch slant on the heat flux distribution and a sequentially coupled thermo-mechanical method is used.The calculated results show that higher residual stress is distributed in and surround the weld zone.Its peak value is very close to the yield strength of base metal.Besides,a large deformation appears in the middle and rear part of the weldment.

  3. Evaluation of Stress Response During Mesiodens Extraction Under General Anesthesia Using Heart Rate Variability.

    Science.gov (United States)

    Hwang, Hye-Won; Hyun, Hong-Keun; Kim, Young-Jae; Kim, Jung-Wook; Shin, Teo Jeon

    2017-05-01

    Stress related to dental treatment can be associated with negative outcomes. Heart rate variability (HRV) is an objective measurement of autonomic nervous system activity. Therefore, HRV was used to identify autonomic nervous system reactions during mesiodens extraction under general anesthesia in children. Electrocardiography was performed with customized software during treatment. HRV parameters were analyzed according to time and frequency domains during each dental procedure (local anesthesia, incision, flap, bone removal, extraction of mesiodens, and suturing). The relations of HRV parameters to age also were determined. Total autonomic nervous system activity decreased markedly after local anesthesia injection. Depending on the responses of sympathetic nerve activity, patients were categorized in a stress group and a nonstress group. The ratio of low-frequency power (LF) to high-frequency power (HF), an indication of sympathetic and parasympathetic balance, increased in the stress group after incision and flap formation. Conversely, the LF/HF ratio decreased during treatment in the nonstress group. However, HR, widely used to evaluate stress responses, did not change statistically during mesiodens extraction in either group. HRV parameters did not differ statistically according to age. The internal stress related to mesiodens extraction can be evaluated more objectively with HRV parameters than with conventional methods. Sympathetic nerve activity in the stress group differed from that in the nonstress group during the treatment procedures. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. A general approach to synthesize asymmetric hybrid nanoparticles by interfacial reactions.

    Science.gov (United States)

    He, Jie; Perez, Maria Teresa; Zhang, Peng; Liu, Yijing; Babu, Taarika; Gong, Jinlong; Nie, Zhihong

    2012-02-29

    Asymmetric multicomponent nanoparticles (AMNPs) offer new opportunities for new-generation materials with improved or new synergetic properties not found in their individual components. There is, however, an urgent need for a synthetic strategy capable of preparing hybrid AMNPs with fine-tuned structural and compositional complexities. Herein, we report a new paradigm for the controllable synthesis of polymer/metal AMNPs with well-controlled size, shape, composition, and morphology by utilizing interfacial polymerization. The hybrid AMNPs display a new level of structural-architectural sophistication, such as controlled domain size and the number of each component of AMNPs. The approach is simple, versatile, cost-effective, and scalable for synthesizing large quantities of AMNPs. Our method may pave a new route to the design and synthesis of advanced breeds of building blocks for functional materials and devices. © 2012 American Chemical Society

  5. An efficient heuristic versus a robust hybrid meta-heuristic for general framework of serial-parallel redundancy problem

    Energy Technology Data Exchange (ETDEWEB)

    Sadjadi, Seyed Jafar [Department of Industrial Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)], E-mail: sjsadjadi@iust.ac.ir; Soltani, R. [Department of Industrial Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2009-11-15

    We present a heuristic approach to solve a general framework of serial-parallel redundancy problem where the reliability of the system is maximized subject to some general linear constraints. The complexity of the redundancy problem is generally considered to be NP-Hard and the optimal solution is not normally available. Therefore, to evaluate the performance of the proposed method, a hybrid genetic algorithm is also implemented whose parameters are calibrated via Taguchi's robust design method. Then, various test problems are solved and the computational results indicate that the proposed heuristic approach could provide us some promising reliabilities, which are fairly close to optimal solutions in a reasonable amount of time.

  6. Professional stress in general practitioners and psychiatrists: The level of psycologic distress and burnout risk

    Directory of Open Access Journals (Sweden)

    Vićentić Sreten

    2010-01-01

    Full Text Available Background/Aim. So far, studies of stress have shown that physicians are at a high risk of sickness from psychic and somatic disorders related to professional stress, that can lead to important disturbance of personal, familiar and professional functionating. The aim of this study was to investigate the doctors exposition level to professional stress, to compare stress level in general practitioners (GP group with that in the group of psychiatrists and risk level for the apperance of burnout syndrome. Methods. This cross-section study included subjects recruited by a random sample method. Thirty General Practice doctors and 30 psychiatrists (totally 60 doctors filled the set of 3 questionnaires: Sociodemographics features, General Health Questionnaire (GHQ; Goldberg D, 1991, and Maslach Burnout Inventory (MBI; Maslach C, 1996. Appropriate statistical procedures (Pearson test, t-test, variance analysis in interpretation of the results were used. Results. A total level of psychic distress measured with the GHQ test in both groups of physicians was very low implying their good mental health. A difference in Burnout risk based on MBI test between the groups was statistically significant (χ2 = 4,286; p < 0.05 only at subscale Personal Accomplishment (MBI-PA; it was a consequence of a higher number of GPs with medium burnout risk (13.3 : 0.0%. However, even 35 physicians from the sample were affected with a high burnout risk measured with subscales Emotional Ehausation (MBI-EE and MBI-DP, showing that both groups of physicians had risk for the appearance of burnout syndrome. Conclusion. The obtained results showed a high burnout risk level in both, GPs and psychiatrists, groups. In both groups there was no presence of psychic disorders (anxiety, depression, insomnia, while there was a high level of emotional ehausation and overtension by job, and also a lower total personal accomplishment. Level of exposition to professional stress is higher in GPs

  7. Creation of a questionnaire to measure stress among nurses engaged in palliative care on general wards.

    Science.gov (United States)

    Terakado, Ako; Watanabe, Takako

    2012-10-01

    This study was conducted to create a questionnaire that measures stress among nurses engaged in palliative care on general wards. Nurses with at least 3 years of experience involved in palliative care on a general ward in six facilities in Japan were the subjects from September 7 to October 4, 2004. A draft questionnaire on stress factors and conditions of stress in nurses engaged in end-of-life care was created, and question items and content meaning were revised to produce 32 question items, with a four-point Likert scale for the responses. Two pretests were conducted. Internal validity was investigated and resulted in 31 question items. Factor analysis using the principal factor method (Varimax rotation) was performed, and Cronbach's coefficient alpha was used to evaluate internal consistency and check reliability. The survey response rate was 94%, with a valid response rate of 98%. Analysis was conducted using responses from 269 participants, of whom 98.9% were female, with a mean age of 35.4 years. The mean length of experience as a nurse was 13.6 years, and the mean length of experience in cancer nursing was 8 years. Results of factor analysis produced eigenvalues of 5.260-1.558 and a cumulative proportion of 58.032%. After two items were deleted, six stress-related factors were identified; their alpha coefficients were 0.753 to 0.912, ensuring high reliability. The questionnaire developed had high internal validity and high reliability, and it can thus serve as a first stage in elucidating stress among nurses engaged in palliative care on general wards.

  8. Critical rotation of general-relativistic polytropic models simulating neutron stars: a post-Newtonian hybrid approximative scheme

    CERN Document Server

    Geroyannis, Vassilis S

    2014-01-01

    We develop a "hybrid approximative scheme" in the framework of the post-Newtonian approximation for computing general-relativistic polytropic models simulating neutron stars in critical rigid rotation. We treat the differential equations governing such a model as a "complex initial value problem", and we solve it by using the so-called "complex-plane strategy". We incorporate into the computations the complete solution for the relativistic effects, this issue representing a significant improvement with regard to the classical post-Newtonian approximation, as verified by extended comparisons of the numerical results.

  9. Improving variable-fidelity surrogate modeling via gradient-enhanced kriging and a generalized hybrid bridge function

    DEFF Research Database (Denmark)

    Han, Zhong Hua; Goertz, Stefan; Zimmermann, Ralf

    2013-01-01

    Variable-fidelity surrogate modeling offers an efficient way to generate aerodynamic data for aero-loads prediction based on a set of CFD methods with varying degree of fidelity and computational expense. In this paper, direct Gradient-Enhanced Kriging (GEK) and a newly developed Generalized Hybrid...... for the aerodynamic coefficients and drag polar of an RAE 2822 airfoil. It is shown that the gradient-enhanced GHBF proposed in this paper is very promising and can be used to significantly improve the efficiency, accuracy and robustness of VFM in the context of aero-loads prediction. © 2012 Elsevier Masson SAS. All...

  10. Photoelastic tomography as hybrid mechanics

    Directory of Open Access Journals (Sweden)

    Errapart A.

    2010-06-01

    Full Text Available Photoelastic tomography is a non-destructive method of 3D stress analysis. It permits determination of normal stress distribution in an arbitrary section of a 3D test object. In case of axial symmetry also the shear stress distribution can be determined directly from the measurement data. To determine also the other stress components one can use equations of the theory of elasticity. Such a combined application of experimental measurements and numerical handling of the equations of the theory of elasticity is named hybrid mechanics. It is shown that if stresses are due to external loads, the hybrid mechanics algorithm is based on the equations of equilibrium and compatibility. In the case of the measurement of the residual stress in glass the compatibility equation can not be applied. In this case a new relationship of axisymmetric thermoelasticity, the generalized sum rule can be applied.

  11. Photoelastic tomography as hybrid mechanics

    Science.gov (United States)

    Aben, H.; Ainola, L.; Errapart, A.

    2010-06-01

    Photoelastic tomography is a non-destructive method of 3D stress analysis. It permits determination of normal stress distribution in an arbitrary section of a 3D test object. In case of axial symmetry also the shear stress distribution can be determined directly from the measurement data. To determine also the other stress components one can use equations of the theory of elasticity. Such a combined application of experimental measurements and numerical handling of the equations of the theory of elasticity is named hybrid mechanics. It is shown that if stresses are due to external loads, the hybrid mechanics algorithm is based on the equations of equilibrium and compatibility. In the case of the measurement of the residual stress in glass the compatibility equation can not be applied. In this case a new relationship of axisymmetric thermoelasticity, the generalized sum rule can be applied.

  12. Work related stress, burnout, job satisfaction and general health of nurses.

    Science.gov (United States)

    Khamisa, Natasha; Oldenburg, Brian; Peltzer, Karl; Ilic, Dragan

    2015-01-12

    Gaps in research focusing on work related stress, burnout, job satisfaction and general health of nurses is evident within developing contexts like South Africa. This study identified the relationship between work related stress, burnout, job satisfaction and general health of nurses. A total of 1200 nurses from four hospitals were invited to participate in this cross-sectional study (75% response rate). Participants completed five questionnaires and multiple linear regression analysis was used to determine significant relationships between variables. Staff issues are best associated with burnout as well as job satisfaction. Burnout explained the highest amount of variance in mental health of nurses. These are known to compromise productivity and performance, as well as affect the quality of patient care. Issues, such as security risks in the workplace, affect job satisfaction and health of nurses. Although this is more salient to developing contexts it is important in developing strategies and intervention programs towards improving nurse and patient related outcomes.

  13. Work Related Stress, Burnout, Job Satisfaction and General Health of Nurses

    Directory of Open Access Journals (Sweden)

    Natasha Khamisa

    2015-01-01

    Full Text Available Gaps in research focusing on work related stress, burnout, job satisfaction and general health of nurses is evident within developing contexts like South Africa. This study identified the relationship between work related stress, burnout, job satisfaction and general health of nurses. A total of 1200 nurses from four hospitals were invited to participate in this cross-sectional study (75% response rate. Participants completed five questionnaires and multiple linear regression analysis was used to determine significant relationships between variables. Staff issues are best associated with burnout as well as job satisfaction. Burnout explained the highest amount of variance in mental health of nurses. These are known to compromise productivity and performance, as well as affect the quality of patient care. Issues, such as security risks in the workplace, affect job satisfaction and health of nurses. Although this is more salient to developing contexts it is important in developing strategies and intervention programs towards improving nurse and patient related outcomes.

  14. The Effect of Magnetic Field and Initial Stress on Fractional Order Generalized Thermoelastic Half-Space

    Directory of Open Access Journals (Sweden)

    Sunita Deswal

    2013-01-01

    Full Text Available The aim of this paper is to study magneto-thermoelastic interactions in an initially stressed isotropic homogeneous half-space in the context of fractional order theory of generalized thermoelasticity. State space formulation with the Laplace transform technique is used to obtain the general solution, and the resulting formulation is applied to the ramp type increase in thermal load and zero stress. Solutions of the problem in the physical domain are obtained by using a numerical method of the Laplace inverse transform based on the Fourier expansion technique, and the expressions for the displacement, temperature, and stress inside the half-space are obtained. Numerical computations are carried out for a particular material for illustrating the results. Results obtained for the field variables are displayed graphically. Some comparisons have been shown in figures to present the effect of fractional parameter, ramp parameter, magnetic field, and initial stress on the field variables. Some particular cases of special interest have been deduced from the present investigation.

  15. Fear learning circuitry is biased toward generalization of fear associations in posttraumatic stress disorder

    OpenAIRE

    Morey, R.A.; Dunsmoor, J E; Haswell, C C; Brown, V M; Vora, A; Weiner, J.; Stjepanovic, D; Wagner, H R; ,; Brancu, Mira; Marx, Christine E.; Naylor, Jennifer C.; Van Voorhees, Elizabeth; Taber, Katherine H.; Beckham, Jean C.

    2015-01-01

    Fear conditioning is an established model for investigating posttraumatic stress disorder (PTSD). However, symptom triggers may vaguely resemble the initial traumatic event, differing on a variety of sensory and affective dimensions. We extended the fear-conditioning model to assess generalization of conditioned fear on fear processing neurocircuitry in PTSD. Military veterans (n=67) consisting of PTSD (n=32) and trauma-exposed comparison (n=35) groups underwent functional magnetic resonance ...

  16. High workload and job stress are associated with lower practice performance in general practice: an observational study in 239 general practices in the Netherlands.

    NARCIS (Netherlands)

    Hombergh, P. van den; Kunzi, B.; Elwyn, G.; Doremalen, J.H.M. van; Akkermans, R.P.; Grol, R.P.T.M.; Wensing, M.J.P.

    2009-01-01

    BACKGROUND: The impact of high physician workload and job stress on quality and outcomes of healthcare delivery is not clear. Our study explored whether high workload and job stress were associated with lower performance in general practices in the Netherlands. METHODS: Secondary analysis of data fr

  17. LOV Histidine Kinase Modulates the General Stress Response System and Affects the virB Operon Expression in Brucella abortus.

    Science.gov (United States)

    Sycz, Gabriela; Carrica, Mariela Carmen; Tseng, Tong-Seung; Bogomolni, Roberto A; Briggs, Winslow R; Goldbaum, Fernando A; Paris, Gastón

    2015-01-01

    Brucella is the causative agent of the zoonotic disease brucellosis, and its success as an intracellular pathogen relies on its ability to adapt to the harsh environmental conditions that it encounters inside the host. The Brucella genome encodes a sensor histidine kinase containing a LOV domain upstream from the kinase, LOVHK, which plays an important role in light-regulated Brucella virulence. In this report we study the intracellular signaling pathway initiated by the light sensor LOVHK using an integrated biochemical and genetic approach. From results of bacterial two-hybrid assays and phosphotransfer experiments we demonstrate that LOVHK functionally interacts with two response regulators: PhyR and LovR, constituting a functional two-component signal-transduction system. LOVHK contributes to the activation of the General Stress Response (GSR) system in Brucella via PhyR, while LovR is proposed to be a phosphate-sink for LOVHK, decreasing its phosphorylation state. We also show that in the absence of LOVHK the expression of the virB operon is down-regulated. In conclusion, our results suggest that LOVHK positively regulates the GSR system in vivo, and has an effect on the expression of the virB operon. The proposed regulatory network suggests a similar role for LOVHK in other microorganisms.

  18. A hybrid model for PM₂.₅ forecasting based on ensemble empirical mode decomposition and a general regression neural network.

    Science.gov (United States)

    Zhou, Qingping; Jiang, Haiyan; Wang, Jianzhou; Zhou, Jianling

    2014-10-15

    Exposure to high concentrations of fine particulate matter (PM₂.₅) can cause serious health problems because PM₂.₅ contains microscopic solid or liquid droplets that are sufficiently small to be ingested deep into human lungs. Thus, daily prediction of PM₂.₅ levels is notably important for regulatory plans that inform the public and restrict social activities in advance when harmful episodes are foreseen. A hybrid EEMD-GRNN (ensemble empirical mode decomposition-general regression neural network) model based on data preprocessing and analysis is firstly proposed in this paper for one-day-ahead prediction of PM₂.₅ concentrations. The EEMD part is utilized to decompose original PM₂.₅ data into several intrinsic mode functions (IMFs), while the GRNN part is used for the prediction of each IMF. The hybrid EEMD-GRNN model is trained using input variables obtained from principal component regression (PCR) model to remove redundancy. These input variables accurately and succinctly reflect the relationships between PM₂.₅ and both air quality and meteorological data. The model is trained with data from January 1 to November 1, 2013 and is validated with data from November 2 to November 21, 2013 in Xi'an Province, China. The experimental results show that the developed hybrid EEMD-GRNN model outperforms a single GRNN model without EEMD, a multiple linear regression (MLR) model, a PCR model, and a traditional autoregressive integrated moving average (ARIMA) model. The hybrid model with fast and accurate results can be used to develop rapid air quality warning systems.

  19. Photosynthesis and growth response of maize (Zea mays L.) hybrids exposed to cadmium stress.

    Science.gov (United States)

    Akhtar, Tasneem; Zia-Ur-Rehman, Muhammad; Naeem, Asif; Nawaz, Rab; Ali, Shafaqat; Murtaza, Ghulam; Maqsood, Muhammad Aamer; Azhar, Muhammad; Khalid, Hinnan; Rizwan, Muhammad

    2017-02-01

    Cadmium (Cd) is a biologically non-essential heavy metal while the cultivation of Cd-tolerant varieties/hybrids (V) seems the most promising strategy for remediation of Cd-contaminated soils. For this, 24-day-old seedlings of seven maize hybrids, DKC 65-25, DKC 61-25, DKC 919, 23-T-16, 32-B-33, 31-P-41, and Syn hybrid, were grown in hydroponic conditions for 21 additional days in various Cd concentrations (0, 5, 10, and 15 μM). Effects of variety, Cd, and their interaction were highly significant (p ≤ 0.05) for studied plant agronomic and physiological traits except the V × Cd interaction for leaf chlorophyll content, root-shoot length, and root dry weight. The Cd accumulation in root and shoot increased gradually with increasing Cd treatments while copper (Cu), zinc (Zn), and manganese (Mn) uptake was decreased in all hybrids. The reduction in root and shoot biomass and Cd uptake was lower in 32-B-33 and 23-T-16 compared to other hybrids. The highest accumulation of Cu, Zn, and Mn was observed in 32-B-33, DK C65-25, and 31-P-41, respectively. The differential uptake and accumulation of Cd by maize hybrids may be useful in selection and breeding for Cd-tolerant genotypes.

  20. GENERAL: Collision avoidance for a mobile robot based on radial basis function hybrid force control technique

    Science.gov (United States)

    Wen, Shu-Huan

    2009-10-01

    Collision avoidance is always difficult in the planning path for a mobile robot. In this paper, the virtual force field between a mobile robot and an obstacle is formed and regulated to maintain a desired distance by hybrid force control algorithm. Since uncertainties from robot dynamics and obstacle degrade the performance of a collision avoidance task, intelligent control is used to compensate for the uncertainties. A radial basis function (RBF) neural network is used to regulate the force field of an accurate distance between a robot and an obstacle in this paper and then simulation studies are conducted to confirm that the proposed algorithm is effective.

  1. THE HYBRID BOUNDARY ELEMENT METHOD BASED ON GENERALIZED WESTERGAARD STRESS FUNCTIONS

    OpenAIRE

    2011-01-01

    Apresenta-se uma formulação particular do método híbrido dos elementos de contorno para a análise de problemas planos de potencial e de elasticidade que, apesar de completamente geral, é apropriada a aplicações de mecânica da fratura. Funções do tipo de Westergaard são usadas como soluções fundamentais, Em uma generalização de uma proposta inicialmente feita por Tada et al. A formulação leva a conceitos de elementos de contorno de deslocamentos semelhante à apresentada por C...

  2. Cavity QED analysis of an exciton-plasmon hybrid molecule via the generalized nonlocal optical response method

    Science.gov (United States)

    Hapuarachchi, Harini; Premaratne, Malin; Bao, Qiaoliang; Cheng, Wenlong; Gunapala, Sarath D.; Agrawal, Govind P.

    2017-06-01

    A metal nanoparticle coupled to a semiconductor quantum dot forms a tunable hybrid system which exhibits remarkable optical phenomena. Small metal nanoparticles possess nanocavitylike optical concentration capabilities due to the presence of strong dipolar excitation modes in the form of localized surface plasmons. Semiconductor quantum dots have strong luminescent capabilities widely used in many applications such as biosensing. When a quantum dot is kept in the vicinity of a metal nanoparticle, a dipole-dipole coupling occurs between the two nanoparticles giving rise to various optical signatures in the scattered spectra. This coupling makes the two nanoparticles behave like a single hybrid molecule. Hybrid molecules made of metal nanoparticles (MNPs) and quantum dots (QDs) under the influence of an external driving field have been extensively studied in literature, using the local response approximation (LRA). However, such previous work in this area was not adequate to explain some experimental observations such as the size-dependent resonance shift of metal nanoparticles which becomes quite significant with decreasing diameter. The nonlocal response of metallic nanostructures which is hitherto disregarded by such studies is a main reason for such nonclassical effects. The generalized nonlocal optical response (GNOR) model provides a computationally less-demanding path to incorporate such properties into the theoretical models. It allows unified theoretical explanation of observed experimental phenomena which previously seemed to require ab initio microscopic theory. In this paper, we analyze the hybrid molecule in an external driving field as an open quantum system using a cavity-QED approach. In the process, we quantum mechanically model the dipole moment operator and the dipole response field of the metal nanoparticle taking the nonlocal effects into account. We observe that the spectra resulting from the GNOR based model effectively demonstrate the

  3. Optimal Constant-Stress Accelerated Degradation Test Plans Using Nonlinear Generalized Wiener Process

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    2016-01-01

    Full Text Available Accelerated degradation test (ADT has been widely used to assess highly reliable products’ lifetime. To conduct an ADT, an appropriate degradation model and test plan should be determined in advance. Although many historical studies have proposed quite a few models, there is still room for improvement. Hence we propose a Nonlinear Generalized Wiener Process (NGWP model with consideration of the effects of stress level, product-to-product variability, and measurement errors for a higher estimation accuracy and a wider range of use. Then under the constraints of sample size, test duration, and test cost, the plans of constant-stress ADT (CSADT with multiple stress levels based on the NGWP are designed by minimizing the asymptotic variance of the reliability estimation of the products under normal operation conditions. An optimization algorithm is developed to determine the optimal stress levels, the number of units allocated to each level, inspection frequency, and measurement times simultaneously. In addition, a comparison based on degradation data of LEDs is made to show better goodness-of-fit of the NGWP than that of other models. Finally, optimal two-level and three-level CSADT plans under various constraints and a detailed sensitivity analysis are demonstrated through examples in this paper.

  4. A novel hybrid kinase is essential for regulating the sigma(B)-mediated stress response of Bacillus cereus.

    Science.gov (United States)

    de Been, Mark; Tempelaars, Marcel H; van Schaik, Willem; Moezelaar, Roy; Siezen, Roland J; Abee, Tjakko

    2010-03-01

    A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor sigma(B) is activated by the RR RsbY. Here we present strong indications that the PP2C-type phosphatase RsbY receives its input from the multi-sensor hybrid kinase BC1008 (renamed RsbK). Genome analyses revealed that, across bacilli, rsbY and rsbK are located in a conserved gene cluster. A B. cereus rsbK deletion strain was shown to be incapable of inducing sigma(B) upon stress conditions and was impaired in its heat adaptive response. Comparison of the wild-type and rsbK mutant transcriptomes upon heat shock revealed that RsbK was primarily involved in the activation of the sigma(B)-mediated stress response. Truncation of the RsbK RR receiver domain demonstrated the importance of this domain for sigma(B) induction upon stress. The domain architecture of RsbK suggests that in the B. cereus group and in other bacilli, environmental and intracellular stress signalling routes are combined into one single protein. This strategy is markedly different from the sigma(B) activation pathway in other low-GC Gram-positives.

  5. [Effects of exogenous silicon on the pollination and fertility characteristics of hybrid rice under heat stress during anthesis].

    Science.gov (United States)

    Wu, Chen-Yang; Chen, Dan; Luo, Hai-Wei; Yao, Yi-min; Wang, Zhi-Wei; Tsutomu, Matsui; Tian, Xiao-Hai

    2013-11-01

    Taking two medium-maturing indica rice hybrids Jinyou 63 and Shanyou 63 as test materials, this paper studied the effects of applying silicon fertilizer on the flag leaf chlorophyll content, photosynthetic properties, antioxidant enzyme activities, malondialdehyde (MDA) content, pollen vigor, anther acid invertase activity, pollination, and seed-setting of hybrid rice under the heat stress during anthesis. This study was conducted in pots and under growth chamber. Soluble solution of silicon fertilizer applied as Na2SiO3 x 9H2O was sprayed on the growing plants after early jointing stage, with three times successively and at an interval of one week. The pots were then moved into growth chamber to subject to normal temperature vs. high temperature (termed as heat stress) for five days. In treatment normal temperature, the average daily temperature was set at 26.6 degrees C, and the maximum daily temperature was set at 29.4 degres C; in treatment high temperature, the average and the maximum daily temperature were set at 33.2 degrees C and 40.1 degrees C, respectively. As compared with the control, applying silicon increased the flag leaf chlorophyll content significantly, improved the net photosynthetic rate and stomatal conductance, decreased the accumulative inter- cellular CO2 concentration, improved the leaf photosynthesis, reduced the MDA content, and improved the activities of SOD, POD and CAT under heat stress. In addition, applying silicon improved the anther acid invertase activity and the pollen vigor, increased the anther basal dehiscence width, total number of pollination per stigma, germinated number, germination rate of pollen, and percentage of florets with more than 10 germinated pollen grains, decreased the percentage of florets with fewer than 20 germinated pollen grains, and thus, alleviated the fertility loss of Jinyou 63 and Shanyou 63 under heat stress by 13.4% and 14.1%, respectively. It was suggested that spraying exogenous silicon in the

  6. What Differentiates Employees' Job Performance Under Stressful Situations: The Role of General Self-Efficacy.

    Science.gov (United States)

    Lu, Chang-Qin; Du, Dan-Yang; Xu, Xiao-Min

    2016-10-02

    The aim of this research is to verify the two-dimensional challenge-hindrance stressor framework in the Chinese context, and investigate the moderating effect of general self-efficacy in the stress process. Data were collected from 164 Chinese employee-supervisor dyads. The results demonstrated that challenge stressors were positively related to job performance while hindrance stressors were negatively related to job performance. Furthermore, general self-efficacy strengthened the positive relationship between challenge stressors and job performance, whereas the attenuating effect of general self-efficacy on the negative relationship between hindrance stressors and job performance was nonsignificant. These findings qualify the two-dimensional challenge-hindrance stressor framework, and support the notion that employees with high self-efficacy benefit more from the positive effect of challenge stressors in the workplace. By investigating the role of an individual difference variable in the challenge-hindrance stressor framework, this research provides a more accurate picture of the nature of job stress, and enhances our understanding of the job stressor-job performance relationship.

  7. Tools for Brain-Computer Interaction: a general concept for a hybrid BCI (hBCI

    Directory of Open Access Journals (Sweden)

    Gernot R. Mueller-Putz

    2011-11-01

    Full Text Available The aim of this work is to present the development of a hybrid Brain-Computer Interface (hBCI which combines existing input devices with a BCI. Thereby, the BCI should be available if the user wishes to extend the types of inputs available to an assistive technology system, but the user can also choose not to use the BCI at all; the BCI is active in the background. The hBCI might decide on the one hand which input channel(s offer the most reliable signal(s and switch between input channels to improve information transfer rate, usability, or other factors, or on the other hand fuse various input channels. One major goal therefore is to bring the BCI technology to a level where it can be used in a maximum number of scenarios in a simple way. To achieve this, it is of great importance that the hBCI is able to operate reliably for long periods, recognizing and adapting to changes as it does so. This goal is only possible if many different subsystems in the hBCI can work together. Since one research institute alone cannot provide such different functionality, collaboration between institutes is necessary. To allow for such a collaboration, a common software framework was investigated.

  8. A general strategy for nanohybrids synthesis via coupled competitive reactions controlled in a hybrid process.

    Science.gov (United States)

    Wang, Rongming; Yang, Wantai; Song, Yuanjun; Shen, Xiaomiao; Wang, Junmei; Zhong, Xiaodi; Li, Shuai; Song, Yujun

    2015-01-01

    A new methodology based on core alloying and shell gradient-doping are developed for the synthesis of nanohybrids, realized by coupled competitive reactions, or sequenced reducing-nucleation and co-precipitation reaction of mixed metal salts in a microfluidic and batch-cooling process. The latent time of nucleation and the growth of nanohybrids can be well controlled due to the formation of controllable intermediates in the coupled competitive reactions. Thus, spatiotemporal-resolved synthesis can be realized by the hybrid process, which enables us to investigate nanohybrid formation at each stage through their solution color changes and TEM images. By adjusting the bi-channel solvents and kinetic parameters of each stage, the primary components of alloyed cores and the second components of transition metal doping ZnO or Al2O3 as surface coatings can be successively formed. The core alloying and shell gradient-doping strategy can efficiently eliminate the crystal lattice mismatch in different components. Consequently, varieties of gradient core-shell nanohybrids can be synthesized using CoM, FeM, AuM, AgM (M = Zn or Al) alloys as cores and transition metal gradient-doping ZnO or Al2O3 as shells, endowing these nanohybrids with unique magnetic and optical properties (e.g., high temperature ferromagnetic property and enhanced blue emission).

  9. Generalized Phenomenological Cyclic Stress-Strain-Strength Characterization of Granular Media.

    Science.gov (United States)

    1984-09-02

    following special form of the general hypoelastic equation to model the behavior of granular media: dij = [a0 dem + a3 "pq d pq] 6ij + 1 dcij + C 2 dem...Phenomitno ogical I C.yclic Stress-Strain-Strength Characterization f Granular M~dia !RSO%.hL APT’.OR(S) M._McVay,_D._Seereeram,_P.__Linton andD... Granular Medi a, Vollow Cylinder. Cyclic Triaxial Test, Plasticity, Prediction Expanding Cavity LClic CTC rests ISTAAC? fCoom w mz_’-. ,f_.V,,A6’V "d

  10. Different perceptions of stress, coping styles, and general well-being among pregnant Chinese women: a structural equation modeling approach.

    Science.gov (United States)

    Lau, Ying; Tha, Pyai Htun; Wong, Daniel Fu Keung; Wang, Yuqiong; Wang, Ying; Yobas, Piyanee Klainin

    2016-02-01

    Few studies have examined different perceptions of stress or explored the positive aspects of well-being among pregnant Chinese women, so there is a need to explore these phenomena in order to fill the research gap. The aim of this study was to examine the relationships among the different perceptions of stress, coping styles, and general well-being using a structural equation modeling approach. We examined a hypothetical model among 755 pregnant Chinese women based on the integration of theoretical models. The Perceived Stress Scale (PSS), the Trait Coping Styles Questionnaire (TCSQ), and the General Well-Being Schedule (GWB) were used to measure perceived stress, coping styles, and general well-being, respectively. A structural equation model showed that positive and negative perceptions of stress significantly influenced positive and negative coping styles, respectively. Different perceptions of stress were significantly associated with general well-being, but different coping styles had no significant effects on general well-being. The model had a good fit to the data (IFI = 0.910, TLI = 0.904, CFI = 0.910, and RMSEA = 0.038). Different perception of stress was able to predict significant differences in coping styles and general well-being.

  11. Quantum, classical, and hybrid QM/MM calculations in solution: General implementation of the ddCOSMO linear scaling strategy

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, Filippo, E-mail: flippari@uni-mainz.de [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); Sorbonne Universités, UPMC Univ. Paris 06, UMR 7616, Laboratoire de Chimie Théorique, F-75005 Paris (France); Sorbonne Universités, UPMC Univ. Paris 06, Institut du Calcul et de la Simulation, F-75005 Paris (France); Scalmani, Giovanni; Frisch, Michael J. [Gaussian, Inc., 340 Quinnipiac St. Bldg. 40, Wallingford, Connecticut 06492 (United States); Lagardère, Louis [Sorbonne Universités, UPMC Univ. Paris 06, Institut du Calcul et de la Simulation, F-75005 Paris (France); Stamm, Benjamin [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); CNRS, UMR 7598 and 7616, F-75005 Paris (France); Cancès, Eric [Université Paris-Est, CERMICS, Ecole des Ponts and INRIA, 6 and 8 avenue Blaise Pascal, 77455 Marne-la-Vallée Cedex 2 (France); Maday, Yvon [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005 Paris (France); Institut Universitaire de France, Paris, France and Division of Applied Maths, Brown University, Providence, Rhode Island 02912 (United States); Piquemal, Jean-Philip [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7616, Laboratoire de Chimie Théorique, F-75005 Paris (France); CNRS, UMR 7598 and 7616, F-75005 Paris (France); Mennucci, Benedetta [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, 56126 Pisa (Italy)

    2014-11-14

    We present the general theory and implementation of the Conductor-like Screening Model according to the recently developed ddCOSMO paradigm. The various quantities needed to apply ddCOSMO at different levels of theory, including quantum mechanical descriptions, are discussed in detail, with a particular focus on how to compute the integrals needed to evaluate the ddCOSMO solvation energy and its derivatives. The overall computational cost of a ddCOSMO computation is then analyzed and decomposed in the various steps: the different relative weights of such contributions are then discussed for both ddCOSMO and the fastest available alternative discretization to the COSMO equations. Finally, the scaling of the cost of the various steps with respect to the size of the solute is analyzed and discussed, showing how ddCOSMO opens significantly new possibilities when cheap or hybrid molecular mechanics/quantum mechanics methods are used to describe the solute.

  12. Stress system dysregulation in pediatric generalized anxiety disorder associated with comorbid depression.

    Science.gov (United States)

    Funke, R; Eichler, A; Distler, J; Golub, Y; Kratz, O; Moll, G H

    2016-12-16

    Because chronic stress is an important risk factor for anxiety states and depressive disorders, we studied hypothalamus-pituitary-adrenal (HPA) axis and sympathetic system activity via changes in cortisol and alpha amylase activity levels in pediatric generalized anxiety disorder (GAD) patients (n = 26) with comorbid depression and a healthy comparison group (n = 26). Morning plasma cortisol and diurnal profiles of salivary cortisol and salivary alpha amylase (sAA) activity were assessed, also reactivity of HPA-axis, sAA activity, and heart rate following a psychosocial stressor (Trier Social Stress Test for children). GAD patients with comorbid depression showed increased morning plasma and salivary cortisol levels, ameliorating throughout in-patient treatment, and higher sAA activity in their diurnal profile. Both HPA and sympathetic activity positively correlated with the severity of anxiety and depression. We also demonstrated a blunted HPA and sympathetic response to acute stress in patients. This pattern of neuroendocrine and sympathetic changes seems to be distinct from the one previously reported in pediatric patients with only social anxiety or depressive disorders. We propose morning plasma and saliva cortisol levels as potential physiological indicators for supporting the evaluation of symptoms' severity and treatment progress in children with GAD and comorbid depressive disorder.

  13. Stress induced birefringence in hybrid TIR/PBG guiding solid photonic crystal fibers

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, Brian Joseph; Olausson, Christina Bjarnal Thulin

    2010-01-01

    We report on two types of polarization maintaining solid photonic crystal fibers that guide light by a combination of a photonic bandgap and total internal reflection. Group and phase birefringence are studied experimentally and numerically for stress-applying parts made from B-doped and F......-doped silica. The stress field originating from Ge-doped cladding rods is shown to interfere with the stress field from the B-doped and F-doped rods. Since the differential expansion coefficients of B-doped and F-doped silica have opposite signs this interference is either destructive or constructive...

  14. Investigating the effect of work stress, general health quality, organizational intelligence and job satisfaction on employee performance

    Directory of Open Access Journals (Sweden)

    Masoud Samadzadeh

    2013-12-01

    Full Text Available During the past few years, there have been tremendous efforts on measuring the effects of different factors such as work stress, general heath quality, etc. on performance of employees. In this paper, we present an empirical investigation to study the effects of work stress, general health, organizational intelligence and job satisfaction on employee performance. The proposed study of this paper uses two questionnaires where one is associated with general heath quality (GHQ with 20 questions and the other one consists of 12 questions, which is associated with work stress. The study chooses a sample of 144 employees from 222 people who worked for one of Islamic Azad University in Iran. Cronbach alphas for work stress, general health, organizational intelligence, job satisfaction and organizational performance are 0.911, 0.895, 0.795, 0.863 and, 0.864, respectively. The results indicate that job satisfaction has the highest influence on organizational performance followed by other factors.

  15. Posttraumatic stress disorder's dysphoria dimension and relations with generalized anxiety disorder symptoms.

    Science.gov (United States)

    Durham, Tory A; Elhai, Jon D; Fine, Thomas H; Tamburrino, Marijo; Cohen, Gregory; Shirley, Edwin; Chan, Philip K; Liberzon, Israel; Galea, Sandro; Calabrese, Joseph R

    2015-07-30

    The present study investigated symptom relations between two highly comorbid disorders--posttraumatic stress disorder (PTSD) and generalized anxiety disorder (GAD)--by exploring their underlying dimensions. Based on theory and prior empirical research it was expected that the dysphoria factor of PTSD would be more highly related to GAD. As part of a longitudinal project of mental health among Ohio National Guard Soldiers, 1266 subjects were administered the Posttraumatic Stress Disorder Checklist (PCL) and Generalized Anxiety Disorder-7 scale (GAD-7). Confirmatory factor analyses (CFAs) were conducted to examine two models of PTSD and to determine which PTSD factors were more related to the GAD factor. The results indicate that the GAD factor was significantly more highly correlated with PTSD's dysphoria factor than with all other PTSD factors, including PTSD's reexperiencing factor, avoidance factor, and hyperarousal factor. Results indicate GAD was not significantly more highly correlated with numbing than most other factors of PTSD. The results are consistent with prior research. Implications of the results are discussed in regards to PTSD in DSM-5, comorbidity and diagnostic specificity.

  16. Effects of natural hybrid and non-hybrid Epichloë endophytes on the response of Hordelymus europaeus to drought stress.

    Science.gov (United States)

    Oberhofer, Martina; Güsewell, Sabine; Leuchtmann, Adrian

    2014-01-01

    Interspecific hybrid endophytes of the genus Epichloë (Ascomycota, Clavicipitaceae) are prevalent in wild grass populations, possibly because of their larger gene variation, resulting in increased fitness benefits for host plants; however, the reasons are not yet known. We tested hypotheses regarding niche expansion mediated by hybrid endophytes, population-dependent interactions and local co-adaptation in the woodland grass Hordelymus europaeus, which naturally hosts both hybrid and non-hybrid endophyte taxa. Seedlings derived from seeds of four grass populations made endophyte free were re-inoculated with hybrid or non-hybrid endophyte strains, or left endophyte free. Plants were grown in the glasshouse with or without drought treatment. Endophyte infection increased plant biomass and tiller production by 10-15% in both treatments. Endophyte types had similar effects on growth, but opposite effects on reproduction: non-hybrid endophytes increased seed production, whereas hybrid endophytes reduced or prevented it completely. The results are consistent with the observation that non-hybrid endophytes in H. europaeus prevail at dry sites, but cannot explain the prevalence of hybrid endophytes. Thus, our results do not support the hypothesis of niche expansion of hybrid-infected plants. Moreover, plants inoculated with native relative to foreign endophytes yielded higher infections, but both showed similar growth and survival, suggesting weak co-adaptation.

  17. Conserved ABC Transport System Regulated by the General Stress Response Pathways of Alpha- and Gammaproteobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Herrou, Julien; Willett, Jonathan W.; Czyz, Daniel M.; Babnigg, Gyorgy; Kim, Youngchang; Crosson, Sean

    2017-03-01

    Brucella abortus sigma(E1) is an EcfG family sigma factor that regulates the transcription of dozens of genes in response to diverse stress conditions and is required for maintenance of chronic infection in a mouse model. A putative ATP-binding cassette transporter operon, bab1_0223-bab1_0226, is among the most highly activated gene sets in the sigma(E1) regulon. The proteins encoded by the operon resemble quaternary ammonium-compatible solute importers but are most similar in sequence to the broadly conserved YehZYXW system, which remains largely uncharacterized. Transcription of yehZYXW is activated by the general stress sigma factor sigma(S) in Enterobacteriaceae, which suggests a functional role for this transport system in bacterial stress response across the classes Alphaproteobacteria and Gammaproteobacteria. We present evidence that B. abortus YehZYXW does not function as an importer of known compatible solutes under physiological conditions and does not contribute to the virulence defect of a sigma(E1)- null strain. The sole in vitro phenotype associated with genetic disruption of this putative transport system is reduced growth in the presence of high Li+ ion concentrations. A crystal structure of B. abortus YehZ revealed a class II periplasmic binding protein fold with significant structural homology to Archaeoglobus fulgidus ProX, which binds glycine betaine. However, the structure of the YehZ ligand-binding pocket is incompatible with high-affinity binding to glycine betaine. This is consistent with weak measured binding of YehZ to glycine betaine and related compatible solutes. We conclude that YehZYXW is a conserved, stress-regulated transport system that is phylogenetically and functionally distinct from quaternary ammonium-compatible solute importers

  18. The role of general and occupational stress in the relationship between workaholism and work-family/family-work conflicts.

    Science.gov (United States)

    Hauk, Mateusz; Chodkiewicz, Jan

    2013-06-01

    The purpose of this study was to analyze the role of general and occupational stress in the relationship between workaholism (recognized in two ways: as addiction and as behavioral tendency) and the intensity of work-family and family-work conflict. The study included 178 working people. The survey was conducted at three stages - half a year before a holiday, right after the holiday and half a year after the holiday. The Excessive Work Involvement Scale (SZAP) by Golińska for the measurement of workaholism recognized as addiction; The Scale of Workaholism as Behavioral Tendencies (SWBT) by Mudrack and Naughton as adapted by Dudek et al for the measurement of workaholism as behavioral tendency; the Perceived Stress Scale by Cohen et al., as adapted by Juczyński for the measurement of general stress; the Scale of Occupational Stress by Stanton in the adaptation of Dudek and Hauk for measurement of occupational stress; the Scale of Work-Family Conflict WFC/FWC by Netemeyer et al. with the Polish adaptation of A.M. Zalewska. Workaholism was measured once - before a holiday, the explained and intervening variables (the level of conflicts and stress, respectively) were measured at three stages. To test the mediating role of general and occupational stress, hierarchical regression analysis as well as the method of bootstrapping were applied. Our results indicate that general stress is an important mediator of the relationship between workaholism recognized as an addiction and work-family conflicts. Occupational stress turned out to be the only mediator in the relationship between workaholism (recognized as an addiction) and the work-family conflict, noted exclusively in the first stage of the study. Both general and occupational stress were not significant mediators in the relationship between workaholism recognized as a behavioral tendency and the conflicts described.

  19. Proteomic Analysis of the Response of Liangyoupeijiu (Super High-Yield Hybrid Rice) Seedlings to Cold Stress

    Institute of Scientific and Technical Information of China (English)

    Ping-Fang Yang; Xiao-Juan Li; Yu Liang; Yu-Xiang Jing; Shi-Hua Shen; Ting-Yun Kuang

    2006-01-01

    Liangyoupeijiu is a super high-yield hybrid rice. Despite its advantages with respect to yield and grain quality, it is sensitive to cold, which keeps it from being widely cultivated. We subjected Liangyoupeijiu seedlings to 4 ℃ cold treatment, then extracted the leaf proteins. After 2-D gel electrophoresis separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, a series of differentially displayed proteins were identified. Some metabolism-associated proteins were found among the downregulated proteins, such as carbamoyl phosphate synthetase, transketolase 1, dihydrolipoamide dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase. The upregulated proteins included both stress-resistance proteins such as nucleoside diphosphate kinase Ⅰ and proteins that are negative for rice growth, such as FtsH-like protein, plastid fusion and/or translocation factor (Pftf) and actin. Our results indicate that cold may inhibit Liangyoupeijiu growth through decreasing metabolic activity and damaging cell structure.

  20. Multivariate Analysis of Grain Yield and Its Attributing Traits in Different Maize Hybrids Grown under Heat and Drought Stress.

    Science.gov (United States)

    Ali, Fawad; Kanwal, Naila; Ahsan, Muhammmad; Ali, Qurban; Bibi, Irshad; Niazi, Nabeel Khan

    2015-01-01

    This study was carried out to evaluate F1 single cross-maize hybrids in four crop growing seasons (2010-2012). Morphological traits and physiological parameters of twelve maize hybrids were evaluated (i) to construct seed yield equation and (ii) to determine grain yield attributing traits of well-performing maize genotype using a previously unexplored method of two-way hierarchical clustering. In seed yield predicting equation photosynthetic rate contributed the highest variation (46%). Principal component analysis data showed that investigated traits contributed up to 90.55% variation in dependent structure. From factor analysis, we found that factor 1 contributed 49.6% variation (P < 0.05) with primary important traits (i.e., number of leaves per plant, plant height, stem diameter, fresh leaves weight, leaf area, stomata conductance, substomata CO2 absorption rate, and photosynthetic rate). The results of two-way hierarchical clustering demonstrated that Cluster III had outperforming genotype H12 (Sultan × Soneri) along with its most closely related traits (photosynthetic rate, stomata conductance, substomata CO2 absorption rate, chlorophyll contents, leaf area, and fresh stem weight). Our data shows that H12 (Sultan × Soneri) possessed the highest grain yield per plant under environmentally stress conditions, which are most likely to exist in arid and semiarid climatic conditions, such as in Pakistan.

  1. Neural networks with multiple general neuron models: a hybrid computational intelligence approach using Genetic Programming.

    Science.gov (United States)

    Barton, Alan J; Valdés, Julio J; Orchard, Robert

    2009-01-01

    Classical neural networks are composed of neurons whose nature is determined by a certain function (the neuron model), usually pre-specified. In this paper, a type of neural network (NN-GP) is presented in which: (i) each neuron may have its own neuron model in the form of a general function, (ii) any layout (i.e network interconnection) is possible, and (iii) no bias nodes or weights are associated to the connections, neurons or layers. The general functions associated to a neuron are learned by searching a function space. They are not provided a priori, but are rather built as part of an Evolutionary Computation process based on Genetic Programming. The resulting network solutions are evaluated based on a fitness measure, which may, for example, be based on classification or regression errors. Two real-world examples are presented to illustrate the promising behaviour on classification problems via construction of a low-dimensional representation of a high-dimensional parameter space associated to the set of all network solutions.

  2. Work Related Stress: Application of a Special Study to the General Business Community.

    Science.gov (United States)

    Gallagher, Denise M.; And Others

    There has been much recent attention given to stress and the negative side effects associated with excessive stress. Employers need to recognize the effect that stress can have on the productivity and attitudes of their employees. To examine work-related stress and to develop stress management strategies, a study was conducted of flight attendants…

  3. General self-efficacy and the effect of hospital workplace violence on doctors’ stress and job satisfaction in China

    Directory of Open Access Journals (Sweden)

    Yongcheng Yao

    2014-08-01

    Full Text Available Objectives: This study aims at exploring associations of general self-efficacy (GSE, workplace violence and doctors' work-related attitudes. Material and Methods: In this study a cross-sectional survey design was applied. Questionnaires were administrated to 758 doctors working in 9 hospitals of Zhengzhou, Henan province, China, between June and October 2010. General information on age, gender, and years of working was collected, and the doctors' experience and witnessing workplace violence, job satisfaction, job initiative, occupational stress as well as GSE were measured. General linear regression analysis was performed in association analyses. Results: Both experiencing and witnessing workplace violence were significantly positively correlated with the level of occupational stress but significantly negatively correlated with job satisfaction, job initiative, and GSE. General self-efficacy significantly modified relationships between both experiencing and witnessing workplace violence with occupational stress (β = 0.49 for experiencing violence; β = 0.43 for witnessing violence; p 0.05. The levels of occupational stress declined significantly with the increase of GSE, while job satisfaction increased significantly along with its increase. The effects of GSE on occupational stress and job satisfaction weakened as the frequency of violence increased. Conclusions: The findings suggest that GSE can modify effects of workplace violence on health care workers' stress and job satisfaction. Enhancing GSE in combination with stress reduction may lead to facilitating health care workers' recovery from workplace violence, and thereby improving their work-related attitudes.

  4. General self-efficacy and the effect of hospital workplace violence on doctors' stress and job satisfaction in China.

    Science.gov (United States)

    Yao, Yongcheng; Wang, Wei; Wang, Faxuan; Yao, Wu

    2014-06-01

    This study aims at exploring associations of general self-efficacy (GSE), workplace violence and doctors' work-related attitudes. In this study a cross-sectional survey design was applied. Questionnaires were administrated to 758 doctors working in 9 hospitals of Zhengzhou, Henan province, China, between June and October 2010. General information on age, gender, and years of working was collected, and the doctors' experience and witnessing workplace violence, job satisfaction, job initiative, occupational stress as well as GSE were measured. General linear regression analysis was performed in association analyses. Both experiencing and witnessing workplace violence were significantly positively correlated with the level of occupational stress but significantly negatively correlated with job satisfaction, job initiative, and GSE. General self-efficacy significantly modified relationships between both experiencing and witnessing workplace violence with occupational stress (β = 0.49 for experiencing violence; β = 0.43 for witnessing violence; p 0.05). The levels of occupational stress declined significantly with the increase of GSE, while job satisfaction increased significantly along with its increase. The effects of GSE on occupational stress and job satisfaction weakened as the frequency of violence increased. The findings suggest that GSE can modify effects of workplace violence on health care workers' stress and job satisfaction. Enhancing GSE in combination with stress reduction may lead to facilitating health care workers' recovery from workplace violence, and thereby improving their work-related attitudes.

  5. Hybrid MPI/OpenMP Implementation of the ORAC Molecular Dynamics Program for Generalized Ensemble and Fast Switching Alchemical Simulations.

    Science.gov (United States)

    Procacci, Piero

    2016-06-27

    We present a new release (6.0β) of the ORAC program [Marsili et al. J. Comput. Chem. 2010, 31, 1106-1116] with a hybrid OpenMP/MPI (open multiprocessing message passing interface) multilevel parallelism tailored for generalized ensemble (GE) and fast switching double annihilation (FS-DAM) nonequilibrium technology aimed at evaluating the binding free energy in drug-receptor system on high performance computing platforms. The production of the GE or FS-DAM trajectories is handled using a weak scaling parallel approach on the MPI level only, while a strong scaling force decomposition scheme is implemented for intranode computations with shared memory access at the OpenMP level. The efficiency, simplicity, and inherent parallel nature of the ORAC implementation of the FS-DAM algorithm, project the code as a possible effective tool for a second generation high throughput virtual screening in drug discovery and design. The code, along with documentation, testing, and ancillary tools, is distributed under the provisions of the General Public License and can be freely downloaded at www.chim.unifi.it/orac .

  6. Numerical Solution to Generalized Burgers'-Fisher Equation Using Exp-Function Method Hybridized with Heuristic Computation

    Science.gov (United States)

    Malik, Suheel Abdullah; Qureshi, Ijaz Mansoor; Amir, Muhammad; Malik, Aqdas Naveed; Haq, Ihsanul

    2015-01-01

    In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE) through substitution is converted into a nonlinear ordinary differential equation (NODE). The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA) is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM), homotopy perturbation method (HPM), and optimal homotopy asymptotic method (OHAM), show that the suggested scheme is fairly accurate and viable for solving such problems. PMID:25811858

  7. Numerical solution to generalized Burgers'-Fisher equation using Exp-function method hybridized with heuristic computation.

    Directory of Open Access Journals (Sweden)

    Suheel Abdullah Malik

    Full Text Available In this paper, a new heuristic scheme for the approximate solution of the generalized Burgers'-Fisher equation is proposed. The scheme is based on the hybridization of Exp-function method with nature inspired algorithm. The given nonlinear partial differential equation (NPDE through substitution is converted into a nonlinear ordinary differential equation (NODE. The travelling wave solution is approximated by the Exp-function method with unknown parameters. The unknown parameters are estimated by transforming the NODE into an equivalent global error minimization problem by using a fitness function. The popular genetic algorithm (GA is used to solve the minimization problem, and to achieve the unknown parameters. The proposed scheme is successfully implemented to solve the generalized Burgers'-Fisher equation. The comparison of numerical results with the exact solutions, and the solutions obtained using some traditional methods, including adomian decomposition method (ADM, homotopy perturbation method (HPM, and optimal homotopy asymptotic method (OHAM, show that the suggested scheme is fairly accurate and viable for solving such problems.

  8. Performance Characterization of a Hybrid Satellite-Terrestrial System with Co-Channel Interference over Generalized Fading Channels.

    Science.gov (United States)

    Javed, Umer; He, Di; Liu, Peilin

    2016-08-05

    The transmission of signals in a hybrid satellite-terrestrial system (HSTS) in the presence of co-channel interference (CCI) is considered in this study. Specifically, we examine the problem of amplify-and-forward (AF)-based relaying in a hybrid satellite-terrestrial link, where the relay node is operating in the presence of a dominant co-channel interferer. It is assumed that direct connection between a source node (satellite) and a destination node (terrestrial receiver) is not available due to masking by obstacles in the surrounding. The destination node is only able to receive signals from the satellite with the help of a relay node located at the ground. In the proposed HSTS, the satellite-relay channel follows the shadowed Rice fading; and the channels of interferer-relay and relay-destination links experience generalized Nakagami-m fading. For the considered AF-based HSTS, we first develop the analytical expression for the moment generating function (MGF) of the overall output signal-to-interference-plus-noise ratio (SINR). Then, based on the derived exact MGF, we derive novel expressions for the average symbol error rate (SER) of the considered HSTS for the following digital modulation techniques: M-ary phase shift keying (M-PSK), M-ary quadrature amplitude modulation (M-QAM) and M-ary pulse amplitude modulation (M-PAM). To significantly reduce the computational complexity for utility in system-level simulations, simple analytical approximation for the exact SER in the high signal-to-noise ratio (SNR) regime is presented to provide key insights. Finally, numerical results and the corresponding analysis are presented to demonstrate the effectiveness of the developed performance evaluation framework and to view the impact of CCI on the considered HSTS under varying channel conditions and with different modulation schemes.

  9. Perceived sources and levels of stress, general self-efficacy and coping strategies in clinical dental students.

    Science.gov (United States)

    Ersan, Nilüfer; Fişekçioğlu, Erdoğan; Dölekoğlu, Semanur; Oktay, İnci; İlgüy, Dilhan

    2017-02-06

    The aims of this study were to identify sources of stress among clinical students and to evaluate the students' perceived levels of stress, general self-efficacy and effective coping strategies in a private dental school environment. The study group consisted of 130 undergraduate clinical dental students in a Turkish private dental school, during the academic year 2014-2015. The students were surveyed using modified version of the dental environment stress (DES) survey, the perceived stress scale, the general self-efficacy scale (G-SES) and the brief coping scale. Age, sex, year of study, history of psychiatric treatment and factors that affected the choice of dentistry were also recorded. Final year and female clinical dental students, who were found to be the most stressful students, had moderate to high perceived stress scores. Total and 'Faculty and administration' related DES scores increased with the year of study. Stressors related to 'Workload' and 'Clinical training' affected females more than males. G-SES scores were higher in male students and students, who had no history of psychiatric treatment. The most and the least common coping strategies were 'Planning' and 'Substance abuse', respectively. 'Religion' was found to be one of the main coping strategies. Stress factors affecting Turkish clinical dental students studying at private dental school differed from the previously reported stress factors affecting students studying at a governmental dental school. Advanced year and female students experienced more stress than the other students.

  10. Optimization and Static Stress Analysis of Hybrid Fiber Reinforced Composite Leaf Spring

    Directory of Open Access Journals (Sweden)

    Luay Muhammed Ali Ismaeel

    2015-01-01

    Full Text Available A monofiber reinforced composite leaf spring is proposed as an alternative to the typical steel one as it is characterized by high strength-to-weight ratio. Different reinforcing schemes are suggested to fabricate the leaf spring. The composite and the typical steel leaf springs are subjected to the same working conditions. A weight saving of about more than 60% can be achieved while maintaining the strength for the structures under consideration. The objective of the present study was to replace material for leaf spring. This study suggests various materials of hybrid fiber reinforced plastics (HFRP. Also the effects of shear moduli of the fibers, matrices, and the composites on the composites performance and responses are discussed. The results and behaviors of each are compared with each other and verified by comparison with analytical solution; a good convergence is found between them. The elastic properties of the hybrid composites are calculated using rules of mixtures and Halpin-Tsi equation through the software of MATLAB v-7. The problem is also analyzed by the technique of finite element analysis (FEA through the software of ANSYS v-14. An element modeling was done for every leaf with eight-node 3D brick element (SOLID185 3D 8-Node Structural Solid.

  11. A Generalized Automatic Hybrid Fuzzy-Based GA-PSO Clustering Approach

    Directory of Open Access Journals (Sweden)

    Amir Hooshang Mazinan, ,

    2014-09-01

    Full Text Available The main contribution of the present research arises from developing the traditional methods in the area of segmentation of brain magnetic resonance imaging (MRI. Contemporary research is now developing techniques to solve the whole considerable problems in this field, such as the fuzzy local information c-mean (FLICM approach that incorporate the local spatial and the gray level information. It should be noted that the present approach is robust against noise, although the high computational complexity is not truly ignored. A novel approach in segmentation of brain MRI has been investigated and presented through the proposed research. Because of so many noises embedded in the acquiring procedure, like eddy currents, the segmentation of the brain MR is now tangibly taken into account as a difficult task. Fuzzy-based clustering algorithm is one of the solutions in the same way. But, it is so sensitive to change through noise and other imaging artifacts. The idea of combining the genetic algorithm (GA and particle swarm optimization (PSO for the purpose of generalizing the FLICM is the ultimate goal in the present investigation, since the computational complexity could actually be reduced. The experiments with a number of simulated images as well as the clinical MRI data illustrate that the proposed approach is applicable and effective.

  12. Hair cortisol concentrations and cortisol stress reactivity in generalized anxiety disorder, major depression and their comorbidity.

    Science.gov (United States)

    Steudte-Schmiedgen, Susann; Wichmann, Susann; Stalder, Tobias; Hilbert, Kevin; Muehlhan, Markus; Lueken, Ulrike; Beesdo-Baum, Katja

    2017-01-01

    Studies investigating cortisol secretion in patients with generalized anxiety disorder (GAD) have reported heterogeneous findings. Further, current knowledge on the specificity of endocrine changes for GAD and/or comorbid major depression (MD) is limited. Hence, the current study investigated long-term integrated cortisol secretion, as indexed by hair cortisol concentrations (HCC), and experimentally-induced cortisol stress reactivity in relation to GAD, MD and their comorbidity. Carefully characterized groups of 17 GAD patients including 8 with comorbid MD (GAD-MD), 12 MD patients and 21 healthy controls were recruited. Alongside psychometric data, HCC (N = 43) and salivary cortisol stress reactivity in response to the Trier Social Stress Test (N = 45) were determined. Findings revealed that MD patients exhibited lower HCC compared to controls and GAD patients, with no differences between the latter two groups. Interestingly, when the GAD group was separated into two groups based on MD comorbidity, lower HCC in MD patients were found compared to controls and GAD-noMD patients, but did not show differences when compared to GAD-MD patients. No HCC differences were seen between GAD-MD or GAD-noMD patients and healthy controls. No TSST group differences emerged. Our findings suggest MD to be related to long-term attenuation in cortisol secretion. While no group differences emerged between patients with GAD, neither with nor without MD, and controls, the current results provide tentative evidence that MD determines long-term endocrine changes, with pure GAD showing a distinct pattern. Future studies are needed to confirm our findings in larger samples of pure and comorbid groups.

  13. Various methods of numerical estimation of generalized stress intensity factors of bi-material notches

    Directory of Open Access Journals (Sweden)

    Klusák J.

    2009-12-01

    Full Text Available The study of bi-material notches becomes a topical problem as they can model efficiently geometrical or material discontinuities. When assessing crack initiation conditions in the bi-material notches, the generalized stress intensity factors H have to be calculated. Contrary to the determination of the K-factor for a crack in an isotropic homogeneous medium, for the ascertainment of the H-factor there is no procedure incorporated in the calculation systems. The calculation of these fracture parameters requires experience. Direct methods of estimation of H-factors need choosing usually length parameter entering into calculation. On the other hand the method combining the application of the reciprocal theorem (Ψ-integral and FEM does not require entering any length parameter and is capable to extract the near-tip information directly from the far-field deformation.

  14. Local well-posedness to inhomogeneous Ericksen-Leslie system with general Leslie stress tensor

    Science.gov (United States)

    Gong, Huajun; Li, Jinkai; Xu, Chen

    2017-02-01

    In this paper, we establish the local well-posedness of strong solutions to the Cauchy problem of the density-dependent liquid crystal system, with general Leslie stress tensor, in R^3. By using a biharmonic regularization argument, and making full use of the property of the intrinsic cancellation of the regularized system, we are able to overcome the difficulties caused by the high-order coupling terms, establish some appropriate a priori estimates, which are independent of the regularized parameter, and consequently obtain a strong solution to the original liquid crystal system, by letting the regularization parameter go to zero. The main advantage of the biharmonic regularization is that it does not destroy the property of the intrinsic cancellation of the original system.

  15. Towards a model for understanding the development of post-traumatic stress and general distress in mental health nurses.

    Science.gov (United States)

    Lee, Joyce; Daffern, Michael; Ogloff, James R P; Martin, Trish

    2015-02-01

    In their daily work, mental health nurses (MHN) are often exposed to stressful events, including patient-perpetrated aggression and violence. Personal safety and health concerns, as well as concern for the physical and psychological well-being of patients, dominate; these concerns have a profound impact on nurses. This cross-sectional study explored and compared the psychological well-being of 196 hospital-based MHN (97 forensic and 99 mainstream registered psychiatric nurses or psychiatric state enrolled nurses). The aim was to examine exposure to inpatient aggression and work stress, and identify factors contributing to the development of post-traumatic stress reactions and general distress. Multiple regression analyses indicated that working in a mainstream setting is associated with increased work stress; however, mainstream and forensic nurses experienced similar psychological well-being. As a group, 14-17% of mainstream and forensic nurses met the diagnostic criteria for post-traumatic stress disorder, and 36% scored above the threshold for psychiatric caseness. A tentative model of post-traumatic stress and general distress in nurses was developed, illustrating the impact of aggression and stress on well-being. The present study affirms that mental health nursing is a challenging and stressful occupation. Implications for organizations, managers, and individual nurses are discussed.

  16. A general approach to fabricate diverse noble-metal (Au, Pt, Ag, Pt/Au)/Fe2O3 hybrid nanomaterials.

    Science.gov (United States)

    Zhang, Jun; Liu, Xianghong; Guo, Xianzhi; Wu, Shihua; Wang, Shurong

    2010-07-19

    A novel, facile, and general one-pot strategy is explored for the synthesis of diverse noble-metal (Au, Pt, Ag, or Pt/Au)/Fe(2)O(3) hybrid nanoparticles with the assistance of lysine (which is a nontoxic, user friendly amino acid that is compatible with organisms) and without using any other functionalization reagents. Control experiments show that lysine, which contains both amino and carboxylic groups, plays dual and crucial roles as both linker and capping agents in attaching noble metals with a small size and uniform distribution onto an Fe(2)O(3) support. Considering the perfect compatibility of lysine with organism, this approach may find potentials in biochemistry and biological applications. Furthermore, this novel route is also an attractive alternative and supplement to the current methods using a silane coupling agent or polyelectrolyte for preparing hybrid nanomaterials. To demonstrate the usage of such hybrid nanomaterials, a chemical gas sensor has been fabricated from the as-synthesized Au/Fe(2)O(3) nanoparticles and investigated for ethanol detection. Results show that the hybrid sensor exhibits significantly improved sensor performances in terms of high sensitivity, low detection limit, better selectivity, and good reproducibility in comparison with pristine Fe(2)O(3). Most importantly, this general approach can be further employed to fabricate other hybrid nanomaterials based on different support materials.

  17. Dimensional structure of DSM-5 posttraumatic stress symptoms: support for a hybrid Anhedonia and Externalizing Behaviors model.

    Science.gov (United States)

    Armour, Cherie; Tsai, Jack; Durham, Tory A; Charak, Ruby; Biehn, Tracey L; Elhai, Jon D; Pietrzak, Robert H

    2015-02-01

    Several revisions to the symptom clusters of posttraumatic stress disorder (PTSD) have been made in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Central to the focus of this study was the revision of PTSD's tripartite structure in DSM-IV into four symptom clusters in DSM-5. Emerging confirmatory factor analytic (CFA) studies have suggested that DSM-5 PTSD symptoms may be best represented by one of two 6-factor models: (1) an Externalizing Behaviors model characterized by a factor which combines the irritability/anger and self-destructive/reckless behavior items; and (2) an Anhedonia model characterized by items of loss of interest, detachment, and restricted affect. The current study conducted CFAs of DSM-5 PTSD symptoms assessed using the PTSD Checklist for DSM-5 (PCL-5) in two independent and diverse trauma-exposed samples of a nationally representative sample of 1484 U.S. veterans and a sample of 497 Midwestern U.S. university undergraduate students. Relative fits of the DSM-5 model, the DSM-5 Dysphoria model, the DSM-5 Dysphoric Arousal model, the two 6-factor models, and a newly proposed 7-factor Hybrid model, which consolidates the two 6-factor models, were evaluated. Results revealed that, in both samples, both 6-factor models provided significantly better fit than the 4-factor DSM-5 model, the DSM-5 Dysphoria model and the DSM-5 Dysphoric Arousal model. Further, the 7-factor Hybrid model, which incorporates key features of both 6-factor models and is comprised of re-experiencing, avoidance, negative affect, anhedonia, externalizing behaviors, and anxious and dysphoric arousal symptom clusters, provided superior fit to the data in both samples. Results are discussed in light of theoretical and empirical support for the latent structure of DSM-5 PTSD symptoms.

  18. Stress, coping, and general health of nurses who work in units that assist AIDS-carriers and patients with

    OpenAIRE

    2008-01-01

    Based on Lazarus and Folkman’s theory about stress and coping, this research aimed at answering questions related to how nurses, who work in two specialized units of a general hospital, evaluate their working environment, their health and how they manage with stressing situations. In the unit of infectious diseases, the nurses’ evaluation of their working environment did not surpass the limits of what is considered as acceptable. In the unit of hematological alterations, the results showed hi...

  19. Prevalence and risk factors for developing posttraumatic stress disorder in a general intensive care population - a literature review

    OpenAIRE

    Nilsen, Cecilie Bræin

    2016-01-01

    Aim: 1) To investigate prevalence of posttraumatic stress disorder (PTSD) and symptoms of posttraumatic stress (PTSS) in a general intensive care patient population, and risk factors for post ICU-PTSD/PTSS. 2) To investigate how instruments and loss to follow-up could influence the prevalence of PTSD/PTSS in this patient population. Background: Studies have found a wide variance of PTSD/PTSS in this patient population. A number of risk factors were associated with developing post-ICU ...

  20. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  1. [Stress, coping, and general health of nurses working at a care unit for patients with AIDS and hematologic diseases].

    Science.gov (United States)

    Britto, Eliane da Silva; Carvalho, Ana Maria Pimenta

    2003-12-01

    Based on Lazarus and Folkman's theory about stress and coping, this research aimed at answering questions related to how nurses, who work in two specialized units of a general hospital, evaluate their working environment, their health and how they manage with stressing situations. In the unit of infectious diseases, the nurses' evaluation of their working environment did not surpass the limits of what is considered as acceptable. In the unit of hematological alterations, the results showed higher stress levels. In both units, the evaluation of their health was considered as satisfactory and the coping strategies were similar.

  2. RpoS differentially affects the general stress response and biofilm formation in the endophytic Serratia plymuthica G3.

    Science.gov (United States)

    Liu, Xiaoguang; Wu, Yan; Chen, Yuanyuan; Xu, Fang; Halliday, Nigel; Gao, Kexiang; Chan, Kok Gan; Cámara, Miguel

    2016-04-01

    The σ(S) subunit RpoS of RNA polymerase functions as a master regulator of the general stress response in Escherichia coli and related bacteria. RpoS has been reported to modulate biocontrol properties in the rhizobacterium Serratia plymuthica IC1270. However, the role of RpoS in the stress response and biofilm formation in S. plymuthica remains largely unknown. Here we studied the role of RpoS from an endophytic S. plymuthica G3 in regulating these phenotypes. Mutational analysis demonstrated that RpoS positively regulates the global stress response to acid or alkaline stresses, oxidative stress, hyperosmolarity, heat shock and carbon starvation, in addition to proteolytic and chitinolytic activities. Interestingly, rpoS mutations resulted in significantly enhanced swimming motility, biofilm formation and production of the plant auxin indole-3-acetic acid (IAA), which may contribute to competitive colonization and environmental fitness for survival. These findings provide further insight into the strain-specific role of RpoS in the endophytic strain G3 of S. plymuthica, where it confers resistance to general stresses encountered within the plant environment. The heterogeneous functionality of RpoS in rhizosphere and endophytic S. plymuthica populations may provide a selective advantage for better adaptation to various physiological and environmental stresses.

  3. Early life stress and later health : Cardiovascular disease and general health among former war evacuees

    OpenAIRE

    Alastalo, Hanna

    2013-01-01

    Experienced stress in childhood might have been so severe that it has effects throughout the life course. It has been suggested that early life stress may extend consequences on psychological and physical well-being. Previous findings focusing upon consequences of early life stress are however limited and mostly based upon retrospective studies. Still little is known about the consequences of early life stress, such as war separation on physical health from a longitudinal aspect. This th...

  4. Functional ecological genomics to demonstrate general and specific responses to abiotic stress

    NARCIS (Netherlands)

    Roelofs, D.; Aarts, M.G.M.; Schat, H.; Straalen, van N.M.

    2008-01-01

    1. Stress is a major component of natural selection in soil ecosystems. The most prominent abiotic stress factors in the field are temperature extremes (heat, cold), dehydration (drought), high salinity and specific toxic compounds such as heavy metals. Organisms are able to deal with these stresses

  5. Stigma-related stress, shame and avoidant coping reactions among members of the general population with elevated symptom levels.

    Science.gov (United States)

    Schibalski, J V; Müller, M; Ajdacic-Gross, V; Vetter, S; Rodgers, S; Oexle, N; Corrigan, P W; Rössler, W; Rüsch, N

    2017-04-01

    It is unclear whether mental illness stigma affects individuals with subthreshold syndromes outside clinical settings. We therefore investigated the role of different stigma variables, including stigma-related stress and shame reactions, for avoidant stigma coping among members of the general population with elevated symptom levels. Based on a representative population survey, general stress resilience, stigma variables, shame about having a mental illness as well as avoidant stigma coping (secrecy and social withdrawal) were assessed by self-report among 676 participants with elevated symptom levels. Stigma variables and resilience were examined as predictors of avoidant stigma coping in a path model. Increased stigma stress was predicted by lower general stress resilience as well as by higher levels of perceived stigma, group identification and perceived legitimacy of discrimination. More shame was associated with higher perceived legitimacy. Lower resilience as well as more perceived stigma, group identification and perceived legitimacy predicted avoidant coping. Stigma stress partly mediated effects of resilience, perceived stigma and group identification on avoidant coping; shame partly mediated effects of perceived legitimacy on coping. Stigma stress and shame were also directly and positively related to avoidant stigma coping. Analyses were adjusted for symptoms, neuroticism and sociodemographic variables. Stigma may affect a larger proportion of the population than previously thought because stigma variables predicted secrecy and withdrawal among members of the general population with elevated, but overall mild symptom levels. Avoidant stigma coping likely has harmful effects, potentially exacerbating pre-existing psychological distress and undermining social networks. This highlights the need to reduce public stigma as well as to support individuals with subthreshold syndromes in their coping with stigma stress and shame reactions. Copyright © 2017

  6. Conserved ABC Transport System Regulated by the General Stress Response Pathways of Alpha- and Gammaproteobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Herrou, Julien; Willett, Jonathan W.; Czyż, Daniel M.; Babnigg, Gyorgy; Kim, Youngchang; Crosson, Sean; Stock, Ann M.

    2016-12-19

    ABSTRACT

    Brucella abortusσE1is an EcfG family sigma factor that regulates the transcription of dozens of genes in response to diverse stress conditions and is required for maintenance of chronic infection in a mouse model. A putative ATP-binding cassette transporter operon,bab1_0223-bab1_0226, is among the most highly activated gene sets in the σE1regulon. The proteins encoded by the operon resemble quaternary ammonium-compatible solute importers but are most similar in sequence to the broadly conserved YehZYXW system, which remains largely uncharacterized. Transcription ofyehZYXWis activated by the general stress sigma factor σSinEnterobacteriaceae, which suggests a functional role for this transport system in bacterial stress response across the classesAlphaproteobacteriaandGammaproteobacteria. We present evidence thatB. abortusYehZYXW does not function as an importer of known compatible solutes under physiological conditions and does not contribute to the virulence defect of a σE1-null strain. The solein vitrophenotype associated with genetic disruption of this putative transport system is reduced growth in the presence of high Li+ion concentrations. A crystal structure ofB. abortusYehZ revealed a class II periplasmic binding protein fold with significant structural homology toArchaeoglobus fulgidusProX, which binds glycine betaine. However, the structure

  7. General and specific combining abilities in a maize (Zea mays L.) test-cross hybrid panel: relative importance of population structure and genetic divergence between parents.

    Science.gov (United States)

    Larièpe, A; Moreau, L; Laborde, J; Bauland, C; Mezmouk, S; Décousset, L; Mary-Huard, T; Fiévet, J B; Gallais, A; Dubreuil, P; Charcosset, A

    2017-02-01

    General and specific combining abilities of maize hybrids between 288 inbred lines and three tester lines were highly related to population structure and genetic distance inferred from SNP data. Many studies have attempted to provide reliable and quick methods to identify promising parental lines and combinations in hybrid breeding programs. Since the 1950s, maize germplasm has been organized into heterotic groups to facilitate the exploitation of heterosis. Molecular markers have proven efficient tools to address the organization of genetic diversity and the relationship between lines or populations. The aim of the present work was to investigate to what extent marker-based evaluations of population structure and genetic distance may account for general (GCA) and specific (SCA) combining ability components in a population composed of 800 inter and intra-heterotic group hybrids obtained by crossing 288 inbred lines and three testers. Our results illustrate a strong effect of groups identified by population structure analysis on both GCA and SCA components. Including genetic distance between parental lines of hybrids in the model leads to a significant decrease of SCA variance component and an increase in GCA variance component for all the traits. The latter suggests that this approach can be efficient to better estimate the potential combining ability of inbred lines when crossed with unrelated lines, and limits the consequences of tester choice. Significant residual GCA and SCA variance components of models taking into account structure and/or genetic distance highlight the variation available for breeding programs within structure groups.

  8. OPTIMIZATION ABOUT COMBINED HYBRID SCHEME WITH 5-PARAMETER STRESS MODE%5参数应力组合杂交格式优化

    Institute of Scientific and Technical Information of China (English)

    聂玉峰; 尹云辉; 周天孝

    2004-01-01

    It is posed in paper [1] that Zero energy-error can be used to realize the optimization of Combined hybrid finite element methods through adjusting the combined factor. In this paper, the optimization method is used to plane 4-node quadrilateral Combined hybrid scheme CH(0-1) which own 5 stress parameters with energy compatibility characteristic. Based on the optimization results, the analysis of components of element stiffness matrix, and the conclusions about numerical stability and convergence, this paper deduces that the optimal form of CH(0-1) element, is let the combined factor take 1, i.e., just base on Hellinger-Reissner variational principle, and take bilinear compatible displacement interpolation instead of enrich-strain Wilson's displacements interpolation for the orthgonality of 5-parameter stresses mode with the derived strain from Wilson bubble displacements and the weak force balance.

  9. Structural basis of a protein partner switch that regulates the general stress response of α-proteobacteria.

    Science.gov (United States)

    Herrou, Julien; Rotskoff, Grant; Luo, Yun; Roux, Benoît; Crosson, Sean

    2012-05-22

    α-Proteobacteria uniquely integrate features of two-component signal transduction (TCS) and alternative sigma factor (σ) regulation to control transcription in response to general stress. The core of this regulatory system is the PhyR protein, which contains a σ-like (SL) domain and a TCS receiver domain. Aspartyl phosphorylation of the PhyR receiver in response to stress signals promotes binding of the anti-σ factor, NepR, to PhyR-SL. This mechanism, whereby NepR switches binding between its cognate σ factor and phospho-PhyR (PhyR∼P), controls transcription of the general stress regulon. We have defined the structural basis of the PhyR∼P/NepR interaction in Caulobacter crescentus and characterized the effect of aspartyl phosphorylation on PhyR structure by molecular dynamics simulations. Our data support a model in which phosphorylation of the PhyR receiver domain promotes its dissociation from the PhyR-SL domain, which exposes the NepR binding site. A highly dynamic loop-helix region (α3-α4) of the PhyR-SL domain plays an important role in PhyR∼P binding to NepR in vitro, and in stress-dependent activation of transcription in vivo. This study provides a foundation for understanding the protein-protein interactions and protein structural dynamics that underpin general stress adaptation in a large and metabolically diverse clade of the bacterial kingdom.

  10. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress

    Directory of Open Access Journals (Sweden)

    Anne eHennig

    2015-05-01

    Full Text Available Woody crops such as poplars (Populus can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested nine-month-old plants of four tetraploid Populus tremula (L. x P. tremuloides (Michx. lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites.

  11. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress.

    Science.gov (United States)

    Hennig, Anne; Kleinschmit, Jörg R G; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites.

  12. The relationship between stressful working conditions and high alcohol consumption and severe alcohol problems in an urban general population

    DEFF Research Database (Denmark)

    Romelsjö, A; Hasin, D; Hilton, M

    1992-01-01

    The relationship between 15 measures of stressful working conditions and high alcohol consumption (35 g 100% ethanol per day or more for men and 25 g or more for women) was studied, using cross-sectional data from a general population survey of 1344 males and 1494 females; the ages 25-64 years...... increased odds ratios were lower when subjects with an alcohol diagnosis at inpatient care during 1980-84 were excluded in the analyses. On the whole, our findings are not conclusive. The strong, but imprecise associations between stressful working conditions and severe alcohol problems, are however......-adjusted odds ratios, were positive and some were negative when high alcohol consumption was the endpoint, but there was a clear variation by sex and social class. Generally the positive associations were stronger among male non-manual employees. Among males, there was a clear association between stressful...

  13. Association between the Five Factor personality traits and perceived stress: is the effect mediated by general self-efficacy?

    DEFF Research Database (Denmark)

    Ebstrup, Jeanette Frost; Eplov, Lene Falgaard; Pisinger, Charlotta

    2011-01-01

    of neuroticism, extroversion, openness, agreeableness, and conscientiousness, and to explore the role of general self-efficacy (GSE). A population-based cross-sectional study was conducted at the Research Centre for Prevention and Health, Denmark, in 2006-2008. Men and women (N=3471) aged 18-69, were randomly......-significant - whilst neuroticism had a positive association. The associations with agreeableness and openness became positive and significant, respectively, when GSE was included. All five personality-stress models were mediated by GSE, with extroversion and conscientiousness having the strongest mediating effect....... The strongest stress-association was found for neuroticism. GSE was shown to change the impact and interpretation of the personality dimensions on perceived stress. These results indicate that GSE is an important factor to consider in the link between personality and perceived stress....

  14. Stability of Posttraumatic Stress Reaction Factors and Their Relation to General Mental Health Problems in Children: A Longitudinal Study

    Science.gov (United States)

    Nygaard, Egil; Jensen, Tine K.; Dyb, Grete

    2012-01-01

    The aim of this study was to evaluate the structure of posttraumatic stress reaction factors and their relation to general mental health problems in Norwegian children exposed to the tsunami on December 26, 2004. A total of 133 children and adolescents (ages 6-17) were interviewed 10 months posttsunami using the UCLA PTSD Reaction Index, and 104…

  15. Defining the structure of the general stress regulon of Bacillus subtilis using targeted microarray analysis and random forest classification.

    NARCIS (Netherlands)

    Nannapaneni, P.; Hertwig, F.; Depke, M.; Hecker, M.; Mader, U.; Volker, U.; Steil, L.; Hijum, S.A.F.T. van

    2012-01-01

    The structure of the SigB-dependent general stress regulon of Bacillus subtilis has previously been characterized by proteomics approaches as well as DNA array-based expression studies. However, comparing the SigB targets published in three previous major transcriptional profiling studies it is obvi

  16. Comparing anger, anger expression, life stress and social support between Korean female nursing and general university students.

    Science.gov (United States)

    Jun, Won Hee; Lee, Gyungjoo

    2017-05-30

    To compare anger, anger expression, life stress and social support among female students at a nursing university and a general university and to examine factors affecting anger in each group. University students typically experience constant stress resulting from factors like academic requirements, personal relationships and career decisions; this tends to promote anger. Particularly, nursing students' anger can negatively affect the quality of care that they provide, and also their mental health. Therefore, anger management of nursing students is very important in the training and development of future nurses. Nursing education needs to confirm factors associated with anger of nursing students compared with general university students to develop specific intervention programs for decreasing their anger levels. A descriptive, cross-sectional design was used. Participants were 286 female students (146 from a nursing university and 140 from a general university); they completed self-report surveys examining anger, anger expression, life stress and social support. A stepwise multiple regression analysis was done to identify factors affecting anger. Data were collected from 15 May-10 June 2016. In the stepwise multiple regression analysis, we entered three anger expression factors, eight life stress factors and social support as explanatory variables; factors affecting anger among nursing students were anger-out and same-sex peer relationship stress. In general university students, anger-out, anger-control and anger-in were identified as factors affecting anger. Becoming proficient in beneficial anger expression techniques and reducing stress from same-sex peer relationships will reduce anger among female nursing students. © 2017 John Wiley & Sons Ltd.

  17. Job Stress of Medical Staffs in General Hospital%综合医院一线医务人员工作应激调查

    Institute of Scientific and Technical Information of China (English)

    王玉林; 刘碧英; 王锐

    2003-01-01

    Objective: To explore the job stress status of medical staffs in general hospital. Methods: A total of 201 medical staffs were sampled from a general hospital in Changsha City, Hunan Province, and their job stress levels were evaluated by the Medical Job Stress Invemory. Results:The subjects from internal medicine department showed silgnificantIy higher job stress level than those from surgical departmem;and the doctors group showed higher stress level in the interpersonal subscale than the nurses group. Condusion:It is important to pay attention to medical staff''s job stress and job burnout in order to improve their mental health levels.

  18. Modified Hybrid Block Iterative Algorithm for Convex Feasibility Problems and Generalized Equilibrium Problems for Uniformly Quasi-ϕ-Asymptotically Nonexpansive Mappings

    Directory of Open Access Journals (Sweden)

    Siwaporn Saewan

    2010-01-01

    Full Text Available We introduce a modified block hybrid projection algorithm for solving the convex feasibility problems for an infinite family of closed and uniformly quasi-ϕ-asymptotically nonexpansive mappings and the set of solutions of the generalized equilibrium problems. We obtain a strong convergence theorem for the sequences generated by this process in a uniformly smooth and strictly convex Banach space with Kadec-Klee property. The results presented in this paper improve and extend some recent results.

  19. Melatonin–sulforaphane hybrid ITH12674 induces neuroprotection in oxidative stress conditions by a ‘drug–prodrug’ mechanism of action

    Science.gov (United States)

    Egea, Javier; Buendia, Izaskun; Parada, Esther; Navarro, Elisa; Rada, Patricia; Cuadrado, Antonio; López, Manuela G; García, Antonio G; León, Rafael

    2015-01-01

    Background and Purpose Neurodegenerative diseases are a major problem afflicting ageing populations; however, there are no effective treatments to stop their progression. Oxidative stress and neuroinflammation are common factors in their pathogenesis. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the master regulator of oxidative stress, and melatonin is an endogenous hormone with antioxidative properties that reduces its levels with ageing. We have designed a new compound that combines the effects of melatonin with Nrf2 induction properties, with the idea of achieving improved neuroprotective properties. Experimental Approach Compound ITH12674 is a hybrid of melatonin and sulforaphane designed to exert a dual drug–prodrug mechanism of action. We obtained the proposed hybrid in a single step. To test its neuroprotective properties, we used different in vitro models of oxidative stress related to neurodegenerative diseases and brain ischaemia. Key Results ITH12674 showed an improved neuroprotective profile compared to that of melatonin and sulforaphane. ITH12674 (i) mediated a concentration-dependent protective effect in cortical neurons subjected to oxidative stress; (ii) decreased reactive oxygen species production; (iii) augmented GSH concentrations in cortical neurons; (iv) enhanced the Nrf2–antioxidant response element transcriptional response in transfected HEK293T cells; and (v) protected organotypic cultures of hippocampal slices subjected to oxygen and glucose deprivation and re-oxygenation from stress by increasing the expression of haem oxygenase-1 and reducing free radical production. Conclusion and Implications ITH12674 combines the signalling pathways of the parent compounds to improve its neuroprotective properties. This opens a new line of research for such hybrid compounds to treat neurodegenerative diseases. PMID:25425158

  20. School-Related Stress, School Support, and Somatic Complaints: A General Population Study.

    Science.gov (United States)

    Torsheim, Torbjorn; Wold, Bente

    2001-01-01

    Examined relationship between school-related stress, social support, and somatic complaints among Norwegian adolescents. Found that students with high levels of school-related stress had a higher odds ratio for weekly headache, abdominal pain, backache, dizziness, and coexisting somatic complaints. For social support, associations were weaker, but…

  1. General synthesis of transition metal oxides hollow nanospheres/nitrogen-doped graphene hybrids via metal-ammine complex chemistry for high performance lithium ion batteries.

    Science.gov (United States)

    Chen, Jiayuan; Wu, Xiaofeng; Gong, Yan; Wang, Pengfei; Li, Wenhui; Mo, Shengpeng; Peng, Shengpan; Tan, Qiangqiang; Chen, Yunfa

    2017-08-30

    We present a general and facile synthesis strategy, on the basis of metal-ammine complex chemistry, in synthesizing hollow transition metal oxides (Co3O4, NiO, CuO-Cu2O and ZnO)/nitrogen-doped graphene hybrids, potentially applied in high performance lithium ion batteries. The oxygen-containing functional groups of graphene oxide play a prerequisite role in the formation of hollow transition metal oxides on graphene nanosheets, and a significant hollowing process occurs only when forming metal (Co2+, Ni2+, Cu2+, or Zn2+)-ammine complex ions. Moreover, the hollowing process is well correlated with complexing capacity between metal ions and NH3 molecules. The significant hollowing process occurs for strong metal-ammine complex ions including Co2+, Ni2+, Cu2+, and Zn2+ ions, and no hollow structures formed for weak and/or non-complex Mn2+ and Fe3+ ions. Simultaneously, this novel strategy can also achieve the directly doping of nitrogen atoms into graphene framework. When used as anodic materials, the electrochemical performance of two typical hollow Co3O4 or NiO/nitrogen-doped graphene hybrids are evaluated. It is demonstrated that these unique nanostructed hybrids, in contrast with the bare counterparts, solid transition metal oxides/nitrogen-doped graphene hybrids, perform the significantly improved specific capacity, superior rate capability and excellent capacity retention. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Reducing the thermal stress in a heterogeneous material stack for large-area hybrid optical silicon-lithium niobate waveguide micro-chips

    Science.gov (United States)

    Weigel, P. O.; Mookherjea, S.

    2017-04-01

    The bonding of silicon-on-insulator (SOI) to lithium niobate-on-insulator (LNOI) is becoming important for a new category of linear and nonlinear micro-photonic optical devices. In studying the bonding of SOI to LNOI through benzocyclobutene (BCB), a popular interlayer bonding dielectric used in hybrid silicon photonic devices, we use thermal stress calculations to suggest that BCB thickness does not affect thermal stress in this type of structure, and instead, thermal stress can be mitigated satisfactorily by matching the handles of the SOI and LNOI. We bond LNOI with a silicon handle to a silicon chip, remove the handle on the LNOI side, and thermally cycle the bonded stack repeatedly from room temperature up to 300°C and back down without incurring thermal stress cracks, which do appear when using LNOI with a lithium niobate handle, regardless of the BCB thickness. We show that this process can be used to create many hybrid silicon-lithium niobate waveguiding structures on a single patterned SOI chip bonded to a large-area (16 mm × 4.2 mm) lithium niobate film.

  3. Unraveling uranium induced oxidative stress related responses in Arabidopsis thaliana seedlings. Part II: responses in the leaves and general conclusions

    Energy Technology Data Exchange (ETDEWEB)

    Vanhoudt, Nathalie, E-mail: nvanhoud@sckcen.be [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Cuypers, Ann [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Horemans, Nele [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Remans, Tony; Opdenakker, Kelly; Smeets, Karen [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Bello, Daniel Martinez [Hasselt University, Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Agoralaan Building D, 3590 Diepenbeek (Belgium); Havaux, Michel [Commissariat a l' Energie Atomique (CEA)/Cadarache, Direction des Sciences du Vivant, Departement d' Ecophysiologie Vegetale et de Microbiologie, Laboratoire d' Ecophysiologie de la Photosynthese, 13108 Saint-Paul-lez-Durance (France); Wannijn, Jean; Van Hees, May [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Vangronsveld, Jaco [Hasselt University, Environmental Biology, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek (Belgium); Vandenhove, Hildegarde [Belgian Nuclear Research Center (SCK-CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2011-06-15

    The cellular redox balance seems an important modulator under heavy metal stress. While for other heavy metals these processes are well studied, oxidative stress related responses are also known to be triggered under uranium stress but information remains limited. This study aimed to further unravel the mechanisms by which plants respond to uranium stress. Seventeen-day-old Arabidopsis thaliana seedlings, grown on a modified Hoagland solution under controlled conditions, were exposed to 0, 0.1, 1, 10 and 100 {mu}M uranium for 1, 3 and 7 days. While in Part I of this study oxidative stress related responses in the roots were discussed, this second Part II discusses oxidative stress related responses in the leaves and general conclusions drawn from the results of the roots and the leaves will be presented. As several responses were already visible following 1 day exposure, when uranium concentrations in the leaves were negligible, a root-to-shoot signaling system was suggested in which plastids could be important sensing sites. While lipid peroxidation, based on the amount of thiobarbituric acid reactive compounds, was observed after exposure to 100 {mu}M uranium, affecting membrane structure and function, a transient concentration dependent response pattern was visible for lipoxygenase initiated lipid peroxidation. This transient character of uranium stress responses in leaves was emphasized by results of lipoxygenase (LOX2) and antioxidative enzyme transcript levels, enzyme capacities and glutathione concentrations both in time as with concentration. The ascorbate redox balance seemed an important modulator of uranium stress responses in the leaves as in addition to the previous transient responses, the total ascorbate concentration and ascorbate/dehydroascorbate redox balance increased in a concentration and time dependent manner. This could represent either a slow transient response or a stable increase with regard to plant acclimation to uranium stress

  4. Early crisis intervention to patients with acute stress disorder in general hospital.

    Science.gov (United States)

    Andoh, Hidehiro; Yamamoto, Kenji; Ichimura, Atsushi; Sato, Shinko; Teraoka, Naoko; Ozono, Hiroko; Kushino, Nobuhisa; Maruyama, Manabu; Matsumoto, Hideo; Yamazaki, Kosuke

    2003-04-01

    This report presents 2 patients who were diagnosed to have acute stress disorder (ASD), received early psychiatric intervention (crisis intervention as a short-term psychotherapy), and subsequently had good outcome. Encounter with an event that causes psychological trauma may induce post-traumatic stress disorder (PTSD). However, the 2 patients described here have shown no particular mental symptoms for more than 2 years after the event and are leading normal lives. Psychological debriefing as a group used to be regarded as effective for the prevention of PTSD, but early identification of the stress-related disorder and intensive treatment of individual patients is recently considered to be more necessary. Both of the 2 patients presented here showed good outcome, and early crisis intervention in individual patients is suggested to be effective for the treatment of stress-related disorders and prevention of PTSD.

  5. Does domestication cause changes in growth reaction norms? A study of farmed, wild and hybrid Atlantic salmon families exposed to environmental stress.

    Directory of Open Access Journals (Sweden)

    Monica Favnebøe Solberg

    Full Text Available One of the most important traits linked with the successful domestication of animals is reducing their sensitivity to environmental stressors in the human controlled environment. In order to examine whether domestication selection in Atlantic salmon Salmo salar L., over approximately ten generations, has inadvertently selected for reduced responsiveness to stress, we compared the growth reaction norms of 29 wild, hybrid and domesticated families reared together under standard hatchery conditions (control and in the presence of a stressor (reduced water level twice daily. The experiment was conducted for a 14 week period. Farmed salmon outgrew wild salmon 1:2.93 in the control tanks, and no overlap in mean weight was displayed between families representing the three groups. Thus, the elevation of the reaction norms differed among the groups. Overall, growth was approximately 25% lower in the stressed tanksl; however, farmed salmon outgrew wild salmon 1:3.42 under these conditions. That farmed salmon maintained a relatively higher growth rate than the wild salmon in the stressed tanks demonstrates a lower responsiveness to stress in the farmed salmon. Thus, flatter reaction norm slopes were displayed in the farmed salmon, demonstrating reduced plasticity for this trait under these specific experimental conditions. For all growth measurements, hybrid salmon displayed intermediate values. Wild salmon displayed higher heritability estimates for body weight than the hybrid and farmed salmon in both environments. This suggests reduced genetic variation for body weight in the farmed contra wild salmon studied here. While these results may be linked to the specific families and stocks investigated, and verification in other stocks and traits is needed, these data are consistent with the theoretical predictions of domestication.

  6. Transcription of Satellite III non-coding RNAs is a general stress response in human cells

    Science.gov (United States)

    Valgardsdottir, Rut; Chiodi, Ilaria; Giordano, Manuela; Rossi, Antonio; Bazzini, Silvia; Ghigna, Claudia; Riva, Silvano; Biamonti, Giuseppe

    2008-01-01

    In heat-shocked human cells, heat shock factor 1 activates transcription of tandem arrays of repetitive Satellite III (SatIII) DNA in pericentromeric heterochromatin. Satellite III RNAs remain associated with sites of transcription in nuclear stress bodies (nSBs). Here we use real-time RT-PCR to study the expression of these genomic regions. Transcription is highly asymmetrical and most of the transcripts contain the G-rich strand of the repeat. A low level of G-rich RNAs is detectable in unstressed cells and a 104-fold induction occurs after heat shock. G-rich RNAs are induced by a wide range of stress treatments including heavy metals, UV-C, oxidative and hyper-osmotic stress. Differences exist among stressing agents both for the kinetics and the extent of induction (>100- to 80.000-fold). In all cases, G-rich transcripts are associated with nSBs. On the contrary, C-rich transcripts are almost undetectable in unstressed cells and modestly increase after stress. Production of SatIII RNAs after hyper-osmotic stress depends on the Tonicity Element Binding Protein indicating that activation of the arrays is triggered by different transcription factors. This is the first example of a non-coding RNA whose transcription is controlled by different transcription factors under different growth conditions. PMID:18039709

  7. Axi-symmetric generalized thermoelastic diffusion problem with two-temperature and initial stress under fractional order heat conduction

    Science.gov (United States)

    Deswal, Sunita; Kalkal, Kapil Kumar; Sheoran, Sandeep Singh

    2016-09-01

    A mathematical model of fractional order two-temperature generalized thermoelasticity with diffusion and initial stress is proposed to analyze the transient wave phenomenon in an infinite thermoelastic half-space. The governing equations are derived in cylindrical coordinates for a two dimensional axi-symmetric problem. The analytical solution is procured by employing the Laplace and Hankel transforms for time and space variables respectively. The solutions are investigated in detail for a time dependent heat source. By using numerical inversion method of integral transforms, we obtain the solutions for displacement, stress, temperature and diffusion fields in physical domain. Computations are carried out for copper material and displayed graphically. The effect of fractional order parameter, two-temperature parameter, diffusion, initial stress and time on the different thermoelastic and diffusion fields is analyzed on the basis of analytical and numerical results. Some special cases have also been deduced from the present investigation.

  8. Sources of stress for students in high school college preparatory and general education programs: group differences and associations with adjustment.

    Science.gov (United States)

    Suldo, Shannon M; Shaunessy, Elizabeth; Thalji, Amanda; Michalowski, Jessica; Shaffer, Emily

    2009-01-01

    Navigating puberty while developing independent living skills may render adolescents particularly vulnerable to stress, which may ultimately contribute to mental health problems (Compas, Orosan, & Grant, 1993; Elgar, Arlett, & Groves, 2003). The academic transition to high school presents additional challenges as youth are required to interact with a new and larger peer group and manage greater academic expectations. For students enrolled in academically rigorous college preparatory programs, such as the International Baccalaureate (IB) program, the amount of stress perceived may be greater than typical (Suldo, Shaunessy, & Hardesty, 2008). This study investigated the environmental stressors and psychological adjustment of 162 students participating in the IB program and a comparison sample of 157 students in general education. Factor analysis indicated students experience 7 primary categories of stressors, which were examined in relation to students' adjustment specific to academic and psychological functioning. The primary source of stress experienced by IB students was related to academic requirements. In contrast, students in the general education program indicated higher levels of stressors associated with parent-child relations, academic struggles, conflict within family, and peer relations, as well as role transitions and societal problems. Comparisons of correlations between categories of stressors and students' adjustment by curriculum group reveal that students in the IB program reported more symptoms of psychopathology and reduced academic functioning as they experienced higher levels of stress, particularly stressors associated with academic requirements, transitions and societal problems, academic struggles, and extra-curricular activities. Applied implications stem from findings suggesting that students in college preparatory programs are more likely to (a) experience elevated stress related to academic demands as opposed to more typical adolescent

  9. A Hybrid Astronomy Course - The Best of Face-to-Face and Online Pedagogy to Create a Very Effective General Astronomy Course

    Science.gov (United States)

    Bhavsar, Suketu P.

    2013-01-01

    A hybrid course formally integrates the best pedagogical practices in a face-to-face class with the unique opportunities and flexibility inherent in an on-line class. I will describe a general astronomy course "The Universe in Ten Weeks" that was developed as a hybrid astronomy course at Cal Poly Pomona. Students interacted on a daily basis in discussions and observations. Class meetings were enormously productive and active. The instructor has daily feedback and came to class knowing the issues and questions that the students faced in their reading and on-line discussions. He knew before the face-to-face class meetings what conceptual challenges the students faced and what they wanted to research further. I will describe many of the techniques as well as the syllabus that made this class so successful for student learning.

  10. Meta-analysis of studies using suppression subtractive hybridization and microarrays to investigate the effects of environmental stress on gene transcription in oysters.

    Directory of Open Access Journals (Sweden)

    Kelli Anderson

    Full Text Available Many microarray and suppression subtractive hybridization (SSH studies have analyzed the effects of environmental stress on gene transcription in marine species. However, there have been no unifying analyses of these data to identify common stress response pathways. To address this shortfall, we conducted a meta-analysis of 14 studies that investigated the effects of different environmental stressors on gene expression in oysters. The stressors tested included chemical contamination, hypoxia and infection, as well as extremes of temperature, pH and turbidity. We found that the expression of over 400 genes in a range of oyster species changed significantly after exposure to environmental stress. A repeating pattern was evident in these transcriptional responses, regardless of the type of stress applied. Many of the genes that responded to environmental stress encoded proteins involved in translation and protein processing (including molecular chaperones, the mitochondrial electron transport chain, anti-oxidant activity and the cytoskeleton. In light of these findings, we put forward a consensus model of sub-cellular stress responses in oysters.

  11. Meta-analysis of studies using suppression subtractive hybridization and microarrays to investigate the effects of environmental stress on gene transcription in oysters.

    Science.gov (United States)

    Anderson, Kelli; Taylor, Daisy A; Thompson, Emma L; Melwani, Aroon R; Nair, Sham V; Raftos, David A

    2015-01-01

    Many microarray and suppression subtractive hybridization (SSH) studies have analyzed the effects of environmental stress on gene transcription in marine species. However, there have been no unifying analyses of these data to identify common stress response pathways. To address this shortfall, we conducted a meta-analysis of 14 studies that investigated the effects of different environmental stressors on gene expression in oysters. The stressors tested included chemical contamination, hypoxia and infection, as well as extremes of temperature, pH and turbidity. We found that the expression of over 400 genes in a range of oyster species changed significantly after exposure to environmental stress. A repeating pattern was evident in these transcriptional responses, regardless of the type of stress applied. Many of the genes that responded to environmental stress encoded proteins involved in translation and protein processing (including molecular chaperones), the mitochondrial electron transport chain, anti-oxidant activity and the cytoskeleton. In light of these findings, we put forward a consensus model of sub-cellular stress responses in oysters.

  12. Symmetry-general least-squares extraction of elastic data for strained materials from ab initio calculations of stress

    Science.gov (United States)

    Le Page, Yvon; Saxe, Paul

    2002-03-01

    A symmetry-general approach for the least-squares, therefore precise, extraction of elastic coefficients for strained materials is reported. It analyzes stresses calculated ab initio for properly selected strains. The problem, its implementation, and its solution strategy all differ radically from a previous energy-strain approach that we published last year, but the normal equations turn out to be amenable to the same constrainment scheme that makes both approaches symmetry general. The symmetry considerations governing the automated selection of appropriately strained models and their Cartesian systems are detailed. The extension to materials under general stress is discussed and implemented. VASP was used for ab initio calculation of stresses. A comprehensive range of examples includes a triclinic material (kyanite) and simple materials with a range of symmetries at zero pressure, MgO under hydrostatic pressure, Ti4As3 under [001] uniaxial strain, and Si under [001] uniaxial stress. The MgO case agrees with recent experimental work including elastic coefficients as well as their first and second derivatives. The curves of elastic coefficients for Si show a gradual increase in the 33 compliance coefficient, leading to a collapse of the material at -11.7 GPa, compared with -12.0 GPa experimentally. Interpretation of results for Be using two approximations [local density (LDA), generalized gradient (GGA)], two approaches (stress strain and energy strain), two potential types (projector augmented wave and ultrasoft), and two quantum engines (VASP and ORESTES) expose the utmost importance of the cell data used for the elastic calculations and the lesser importance of the other factors. For stiffness at relaxed cell data, differences are shown to originate mostly in the considerable overestimation of the residual compressive stresses at x-ray cell data by LDA, resulting in a smaller relaxed cell, thus larger values for diagonal stiffness coefficients. The symmetry

  13. Rayleigh Waves in Generalized Magneto-Thermo-Viscoelastic Granular Medium under the Influence of Rotation, Gravity Field, and Initial Stress

    Directory of Open Access Journals (Sweden)

    A. M. Abd-Alla

    2011-01-01

    Full Text Available The surface waves propagation in generalized magneto-thermo-viscoelastic granular medium subjected to continuous boundary conditions has been investigated. In addition, it is also subjected to thermal boundary conditions. The solution of the more general equations are obtained for thermoelastic coupling. The frequency equation of Rayleigh waves is obtained in the form of a determinant containing a term involving the coefficient of friction of a granular media which determines Rayleigh waves velocity as a real part and the attenuation coefficient as an imaginary part, and the effects of rotation, magnetic field, initial stress, viscosity, and gravity field on Rayleigh waves velocity and attenuation coefficient of surface waves have been studied in detail. Dispersion curves are computed numerically for a specific model and presented graphically. Some special cases have also been deduced. The results indicate that the effect of rotation, magnetic field, initial stress, and gravity field is very pronounced.

  14. The relationship between stressful working conditions and high alcohol consumption and severe alcohol problems in an urban general population

    DEFF Research Database (Denmark)

    Romelsjö, A; Hasin, D; Hilton, M

    1992-01-01

    The relationship between 15 measures of stressful working conditions and high alcohol consumption (35 g 100% ethanol per day or more for men and 25 g or more for women) was studied, using cross-sectional data from a general population survey of 1344 males and 1494 females; the ages 25-64 years...... in metropolitan Stockholm in 1984. In a longitudinal component of the study, hospitalization and mortality with alcohol-related diagnosis was assessed during 1984-90, and also the association between previous experience of unemployment and high alcohol consumption. Some of the associations, expressed as age......-adjusted odds ratios, were positive and some were negative when high alcohol consumption was the endpoint, but there was a clear variation by sex and social class. Generally the positive associations were stronger among male non-manual employees. Among males, there was a clear association between stressful...

  15. Prevalence of post-traumatic stress disorder in patients with previous myocardial infarction consulting in general practice

    OpenAIRE

    Jones, Rupert CM; Chung, Man C; Berger, Zoë; Campbell, John L.

    2007-01-01

    Reported prevalence of myocardial infarction-related post-traumatic stress disorder (PTSD) varies from 0 to 25%. PTSD after myocardial infarction may affect quality of life, cardiovascular outcomes, and health service usage. Of 164 patients with previous myocardial infarction, 111 participated in the study and 36 had PTSD, giving a prevalence of 32%; the lowest possible estimate being 22%. PTSD was associated with significantly worse general health than that of individuals without PTSD. Preva...

  16. [原著]Effects of personality traits and work-related attitudes on job stress among nurses in general hospitals

    OpenAIRE

    2013-01-01

    Purpose: We aimed to clarify whether personality traits and work-related attitudes affect job stress among medical care professionals. Methods: Subjects were 455 nurses (59 males, 396 females) working in general hospitals. Seven dimensions of personality traits, i.e., novelty seeking (NS), harm avoidance (HA), reward dependence (RD), persistence (P), self-directedness (SD), cooperativeness (C) and selftranscendence (ST), were assessed by using the Temperament Character Inventory-125. A 15-ite...

  17. Stress-energy distribution for a cylindrical artificial gravity field via the Darmois-Israel junction conditions of general relativity

    Science.gov (United States)

    Istrate, Nicolae; Lindner, John

    2014-03-01

    We design an Earth-like artificial gravity field using the Darmois-Israel junction conditions of general relativity to connect the flat spacetime outside an infinitesimally thin cylinder to the curved spacetime inside. In the calculation of extrinsic curvature, our construction exploits Earth's weak gravity, which implies similar inside and outside curvatures, to approximate the unit normal inside by the negative unit normal outside. The stress-energy distribution on the cylinder's sides includes negative energy density.

  18. Stress

    Science.gov (United States)

    ... diabetes. Shopdiabetes.org: Your Stress-Free System for Family Dinners! - 2017-03-book-oclock-scramble.html Shopdiabetes.org Your Stress-Free System for Family Dinners! A year of delicious meals to help prevent ...

  19. Stress

    Science.gov (United States)

    ... 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

  20. General Deposition of Metal-Organic Frameworks on Highly Adaptive Organic-Inorganic Hybrid Electrospun Fibrous Substrates.

    Science.gov (United States)

    Liu, Chang; Wu, Yi-Nan; Morlay, Catherine; Gu, Yifan; Gebremariam, Binyam; Yuan, Xiao; Li, Fengting

    2016-02-01

    Electrospun nanofibrous mats are ideal substrates for metal-organic frameworks (MOFs) crystal deposition because of their specific structural parameters and chemical tenability. In this work, we utilized organic-inorganic hybrid electrospun fibrous mats as support material to study the deposition of various MOF particles. HKUST-1 and MIL-53(Al) were produced through solvothermal method, while ZIF-8 and MIL-88B(Fe) were prepared using microwave-induced heating method. The synthesis procedure for both methods were simple and effective because the hybrid nanofibrous mats showed considerable affinity to MOF particles and could be used without additional modifications. The obtained MOF composites exhibited effective incorporation between MOF particles and the porous substrates. MIL-53(Al) composite was applied as fibrous sorbent and showed enhanced adsorption capacity and removal rate, as well as easier operation, compared with thepowdered sample. Moreover, MIL-53(Al) composite was easier to be regenerated compared with powder form.

  1. The parasite-stress theory may be a general theory of culture and sociality.

    Science.gov (United States)

    Fincher, Corey L; Thornhill, Randy

    2012-04-01

    In the target article, we presented the hypothesis that parasite-stress variation was a causal factor in the variation of in-group assortative sociality, cross-nationally and across the United States, which we indexed with variables that measured different aspects of the strength of family ties and religiosity. We presented evidence supportive of our hypothesis in the form of analyses that controlled for variation in freedom, wealth resources, and wealth inequality across nations and the states of the USA. Here, we respond to criticisms from commentators and attempt to clarify and expand the parasite-stress theory of sociality used to fuel our research presented in the target article.

  2. Thermal stress response of General Purpose Heat Source (GPHS) aeroshell material

    Science.gov (United States)

    Grinberg, I. M.; Hulbert, L. E.; Luce, R. G.

    1980-01-01

    A thermal stress test was conducted to determine the ability of the GPHS aeroshell 3 D FWPF material to maintain physical integrity when exposed to a severe heat flux such as would occur from prompt reentry of GPHS modules. The test was performed in the Giant Planetary Facility at NASA's Ames Research Center. Good agreement was obtained between the theoretical and experimental results for both temperature and strain time histories. No physical damage was observed in the test specimen. These results provide initial corroboration both of the analysis techniques and that the GPHS reentry member will survive the reentry thermal stress levels expected.

  3. Mediator and label free estimation of stress biomarker using electrophoretically deposited Ag@AgO-polyaniline hybrid nanocomposite.

    Science.gov (United States)

    Kaushik, Ajeet; Vasudev, Abhay; Arya, Sunil K; Bhansali, Shekhar

    2013-12-15

    Cortisol, a steroid hormone, is an important biomarker for psychological stress and its detection is gaining prominence for personalized health monitoring. In present work, electrophoretically deposited nanocomposite films of polyaniline (PANI) and core-shell Ag@AgO nanoparticles (NP~5 nm) have been explored as an electro-active nanostructured platform for Anti-cortisol antibody (Anti-Cab) immobilization for electrochemical immunosensing of cortisol. Covalent binding of Anti-Cab onto Ag@AgO-PANI nanocomposite was achieved using EDC/NHS chemistry, which results in the amide bond formation between amino groups of PANI and COOH groups of anti-Cab. Nonspecific binding sites on the immunosensing electrodes were blocked using bovine serum albumin (BSA). The uniform distribution of electro-active and surface charged Ag@AgO NP in PANI matrix results in a nanoporous granular morphology (roughness~10 nm) that provides a functionalized conductive microenvironment for Anti-Cab immobilization. The BSA/Anti-Cab/Ag@AgO-PANI/Au bioelectrodes have been characterized using electrochemical impedance technique (EIS), cyclic voltammetric (CV) technique and atomic force microscopic (AFM) technique, respectively. In CV studies nanocomposite exhibited characteristic response current peak corresponding to AgO NP (0.25 V) with large magnitude of current response and resulted in high electron transport at the electrode-electrolyte interface without a mediator. Electrochemical response studies via CV for the fabricated BSA/Anti-Cab/Ag@AgO-PANI/Au immunosensor as a function of cortisol concentration exhibited a wide linear detection range of 1 pM-1 µM, a detection limit of 0.64 pM mL(-1)(lower than ELISA), and high sensitivity 66 µA M(-1) with a regression coefficient of 0.998. The findings of present work may explore the application of Ag@AgO-PANI hybrid nanocomposite to detect cortisol and other biomarkers for point-of-care application. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Stress-related mental disorders with sick leave: a minimal intervention in general practice

    NARCIS (Netherlands)

    Bakker, I.M.

    2007-01-01

    1. Introduction As stated in chapter 1, this study is carried out because patients and their care-givers have much to gain by the development and implementation of effective care for patients on sick leave having stress-related mental disorders (SMDs). Most people having SMDs with sick leave consult

  5. Oral manifestations of stress-related disorders in the general population of Ludhiana

    Directory of Open Access Journals (Sweden)

    Damanpreet Kaur

    2016-01-01

    Full Text Available Introduction: Oral diseases associated with psychological disorders have long been known in medicine. Emotional as well as psychological factors may act as significant risk factors in the initiation and progression of oromucosal diseases. Aims and Objectives: The aim of this study was to determine a correlation between stress and development of certain oral conditions such as lichen planus, myofacial pain dysfunction syndrome, xerostomia, bruxism, aphthous ulcers, and burning mouth syndrome. Materials and Methods: An observational comparative study was conducted among patients reporting to the Department of Oral Medicine and Radiology. A total of 130 patients gave a positive history of oral lesions, out of which 62 were stress related and the other 68 patients served as the control group (oral lesions with no history of stress. All these patients were subjected to routine systemic and oral examination. The results obtained were statistically compared using P value, t-test, and Chi-square test. Results: It was found that lichen planus and burning mouth syndrome were more common in females and myofacial pain dysfunction syndrome was prevalent in males. Xerostomia was found to increase with age. Conclusion: It was concluded that, though the etiology of most oral lesions is not known, the role of stress and other psychogenic factors cannot be ruled out in their occurrence.

  6. Stress-related mental disorders with sick leave: a minimal intervention in general practice

    NARCIS (Netherlands)

    Bakker, I.M.

    2007-01-01

    1. Introduction As stated in chapter 1, this study is carried out because patients and their care-givers have much to gain by the development and implementation of effective care for patients on sick leave having stress-related mental disorders (SMDs). Most people having SMDs with sick leave consult

  7. General inflammation and stress in patients with intestinal protozoan infections in two hospitals in Tehran

    Directory of Open Access Journals (Sweden)

    Vahdat Haji Hoseinlou

    2015-08-01

    Conclusion: Based on the results of this study, parasitic infection (intestinal protozoa as a stressor factor can increase serum cortisol concentration. In addition, intestinal protozoa was reduced immune system sensitivity and function. It seems that the neutrophil to lymphocyte ratio can be a potential useful parameters for evaluating the stress system activity and function in patients infected with the intestinal protozoa.

  8. Childhood Posttraumatic Stress Disorder: Diagnosis, Treatment, and School Reintegration. General Articles

    Science.gov (United States)

    Cook-Cottone, Catherine

    2004-01-01

    Childhood, in our culture, does not preclude exposure to trauma. Sexual abuse, physical abuse, natural disaster, urban violence, school violence, and terrorism result in significant numbers of children with posttraumatic stress disorder (PTSD) symptomatology. Many factors contribute to symptomatic expression, with some children showing few effects…

  9. Yield and yield components of hybrid corn (Zea mays L.) as affected by mycorrhizal symbiosis and zinc sulfate under drought stress.

    Science.gov (United States)

    Sajedi, N A; Ardakani, M R; Rejali, F; Mohabbati, F; Miransari, Mohammad

    2010-12-01

    With respect to the significance of improving hybrid corn performance under stress, this experiment was conducted at the Islamic Azad University, Arak Branch, Iran. A complete randomized block design with three levels of irrigations (at 100%, 75% and 50% crop water requirement), two levels of arbuscular mycorrhizal (AM) fungi (Glumus intraradisis) (including control), and three levels of zinc (Zn) sulfate (0, 25 and 45 kg ha(-1)), was performed. Results of the 2-year experiments indicated that irrigation treatment significantly affected corn yield and its components at P = 1%. AM fungi and increasing Zn levels also resulted in similar effects on corn growth and production. Although AM fungi did not significantly affect corn growth at the non-stressed irrigation treatment, at moderate drought stress AM fungi significantly enhanced corn quality and yield relative to the control treatment. The combined effects of AM fungi and Zn sulfate at 45 kg ha(-1) application significantly affected corn growth and production. In addition, the tripartite treatments significantly enhanced corn yield at P = 1%. Effects of Zn and AM fungi on plant growth under drought stress is affected by the stress level.

  10. The Role of Generalized Explicit and Implicit Guilt and Shame in Interpersonal Traumatization and Posttraumatic Stress Disorder.

    Science.gov (United States)

    Bockers, Estelle; Roepke, Stefan; Michael, Lars; Renneberg, Babette; Knaevelsrud, Christine

    2016-02-01

    Posttraumatic stress disorder (PTSD) and interpersonal traumatization are frequently associated with trauma-related guilt and shame. However, research on generalized guilt and shame in PTSD is lacking. The aim of this study was to investigate generalized explicit and implicit guilt and shame in interpersonal traumatization and PTSD. Interpersonally traumatized women either with PTSD (n = 28) or without PTSD (n = 32) and 32 nontraumatized women completed the Test of Self-Conscious Affect-3 and the Implicit Association Test to measure explicit and implicit guilt and shame. Explicit guilt and shame were significantly higher in women with PTSD than in traumatized women without PTSD. Traumatized women without PTSD showed significantly higher levels of explicit guilt and shame than nontraumatized women did. PTSD was associated with implicit guilt but not implicit shame. In addition to trauma-related guilt and shame, generalized explicit guilt and shame and implicit guilt seem to play a crucial role in PTSD.

  11. Responses to NaCl stress of cultivated and wild tomato species and their hybrids in callus cultures.

    Science.gov (United States)

    Cano, E A; Pérez-Alfocea, F; Moreno, V; Bolarin, M C

    1996-06-01

    If in vitro culture is to be used for evaluating the salt tolerance of tomato hybrids and segregant populations in a breeding programme, it is previously necessary to get quick and reliable traits. In this work, growth and physiological responses to salinity of two interspecific hybrids between the cultivated tomato (Lycopersicon esculentum Mill) and its wild salt-tolerant species L pennellii are compared to those of their parents. The leaf callus of the first subculture was grown on media amended with 0, 35, 70, 105, 140, 175 and 210 mM NaCl for 40 days. Relative fresh weight growth of callus in response to increased salinity in the culture medium was much greater in L pennellii than in the tomato cultivars, and greater in the hybrids than in the wild species. Moreover, the different salt tolerance degree of hybrids was related to that of female parents. At high salt levels, only Cl(-) accumulation was higher in L pennellii than in tomato cultivars, whereas in the hybrids both Cl(-), and Na(+) accumulation were higher than in their parents. Proline increased with salinity in the callus of all genotypes; these increases were much higher in the tomato cultivars than in L pennellii, and the hybrids showed a similar response to that of the wild species. Salt-treated callus of the tomato cultivars showed significant increases in valine, isoleucine and leucine contents compared to control callus tissue. In contrast, these amino acids in callus tissues of the wild species and hybrids showed a tendency to decrease with increasing salinity.

  12. Isolation and characterization of csbB, a gene controlled by Bacillus subtilis general stress transcription factor sigma B.

    Science.gov (United States)

    Akbar, S; Price, C W

    1996-10-24

    In the bacterium Bacillus subtilis (Bs), the alternative transcription factor sigma B is activated by environmental stresses to control the expression of a large set of unlinked genes. However, the range of physiological functions mediated by these sigma B-controlled genes is presently unknown. We report here that the newly identified gene csbB is under the dual control of a sigma B-dependent and a sigma B-independent promoter. The predicted product of csbB is a 329 residue protein containing two potential membrane-spanning segments in its C-terminal region, leading us to speculate that one class of sigma B-controlled genes acts to modify the cell envelope as part of the general stress response.

  13. Five Year Clinical Evaluation of Restorations Placed in a Low Shrinkage Stress Composite in UK General Dental Practices.

    Science.gov (United States)

    Burke, F J Trevor; Crisp, Russell J; James, Ali; Mackenzie, Louis; Thompson, Owen; Pal, A; Sands, Peter; Palin, William M

    2017-06-01

    This paper evaluates the five year clinical evaluation of restorations formed in a low shrinkage stress resin composite material (3M ESPE Filtek Silorane, Seefeld, Germany) and placed in the general dental practices of five members of the PREP Panel, a group of UK practice-based researchers. Results indicated satisfactory performance of the material under evaluation, other than for marginal staining, which affected 60% of the restorations evaluated after five years, albeit with less than 10% of the circumference of the restorations being affected. The low shrinkage stress material, Filtek Silorane™, demonstrated good clinical performance in the majority of parameters which were assessed at five years. Copyright© 2017 Dennis Barber Ltd.

  14. Development of a Generalized Version of the Poisson-Nernst-Planck Equations Using the Hybrid Mixture Theory: Presentation of 2D Numerical Examples

    DEFF Research Database (Denmark)

    Johannesson, Björn

    2010-01-01

    A numerical scheme for the transient solution of generalized version of the Poisson-Nernst-Planck equations is presented. The finite element method is used to establish the coupled non-linear matrix system of equations capable of solving the present problem iteratively. The Poisson-Nernst-Planck ......A numerical scheme for the transient solution of generalized version of the Poisson-Nernst-Planck equations is presented. The finite element method is used to establish the coupled non-linear matrix system of equations capable of solving the present problem iteratively. The Poisson......, however, coupled in both directions. The governed set of equations is derived from a simplified version of the so-called hybrid mixture theory (HMT). This theory is a special version of the more ‘classical’ continuum mixture theories in the sense that it works with averaged equations at macro...

  15. New insights in dehydration stress behavior of two maize hybrids using advanced distributed reactivity model (DRM). Responses to the impact of 24-epibrassinolide

    Science.gov (United States)

    Janković, Bojan; Janković, Marija; Nikolić, Bogdan; Dimkić, Ivica; Lalević, Blažo; Raičević, Vera

    2017-01-01

    Proposed distributed reactivity model of dehydration for seedling parts of two various maize hybrids (ZP434, ZP704) was established. Dehydration stresses were induced thermally, which is also accompanied by response of hybrids to heat stress. It was found that an increased value of activation energy counterparts within radicle dehydration of ZP434, with a high concentration of 24-epibrassinolide (24-EBL) at elevated operating temperatures, probably causes activation of diffusion mechanisms in cutin network and may increases likelihood of formation of free volumes, large enough to accommodate diffusing molecule. Many small random effects were detected and can be correlated with micro-disturbing in a space filled with water caused by thermal gradients, increasing capillary phenomena, and which can induce thermo-capillary migration. The influence of seedling content of various sugars and minerals on dehydration was also examined. Estimated distributed reactivity models indicate a dependence of reactivity on structural arrangements, due to present interactions between water molecules and chemical species within the plant. PMID:28644899

  16. [Construction of suppression subtractive hybridization (SSH) library of copepod Pseudodiaptomous annandalei and its ferritin cDNA cloning and differential expression under nickel stress].

    Science.gov (United States)

    Jiang, Jie-Lan; Wang, Gui-Zhong; Wu, Li-Sheng; Li, Shao-Jing

    2012-07-01

    To study the molecular response mechanisms of copepod to nickel stress, a suppression subtractive hybridization (SSH) cDNA library of Pseudodiaptomous annandalei under nickel stress was constructed by using SSH technique, and a total of 140 clones were randomly picked from the growing colonies and identified by PCR. The recombinant rate of the library was 98.6%, and the volume of the library was 1.12 x 10(6) cfu. After the recombinant plasmids were sequenced, a partial cDNA fragment of ferritin was recognized based on BLAST searches in NCBI, with a size of 859 bp and continuously encoding 170 amino acid residues. The semi-quantitative PCR results showed that the ferritin cDNA under 24 h nickel stress was distinctly up-regulated. The successful construction of the SSH library and the obtaining of ferritin cDNA fragment would supply basis for the further study of the molecular response mechanisms of copepod to nickel stress.

  17. Reduced angiotensin II levels cause generalized vascular dysfunction via oxidant stress in hamster cheek pouch arterioles.

    Science.gov (United States)

    Priestley, Jessica R C; Buelow, Matthew W; McEwen, Scott T; Weinberg, Brian D; Delaney, Melanie; Balus, Sarah F; Hoeppner, Carlyn; Dondlinger, Lynn; Lombard, Julian H

    2013-09-01

    We investigated the effect of suppressing plasma angiotensin II (ANG II) levels on arteriolar relaxation in the hamster cheek pouch. Arteriolar diameters were measured via television microscopy during short-term (3-6days) high salt (HS; 4% NaCl) diet and angiotensin converting enzyme (ACE) inhibition with captopril (100mg/kg/day). ACE inhibition and/or HS diet eliminated endothelium-dependent arteriolar dilation to acetylcholine, endothelium-independent dilation to the NO donor sodium nitroprusside, the prostacyclin analogs carbacyclin and iloprost, and the KATP channel opener cromakalim; and eliminated arteriolar constriction during KATP channel blockade with glibenclamide. Scavenging of superoxide radicals and low dose ANG II infusion (25ng/kg/min, subcutaneous) reduced oxidant stress and restored arteriolar dilation in arterioles of HS-fed hamsters. Vasoconstriction to topically-applied ANG II was unaffected by HS diet while arteriolar responses to elevation of superfusion solution PO2 were unaffected (5% O2, 10% O2) or reduced (21% O2) by HS diet. These findings indicate that sustained exposure to low levels of circulating ANG II leads to widespread dysfunction in endothelium-dependent and independent vascular relaxation mechanisms in cheek pouch arterioles by increasing vascular oxidant stress, but does not potentiate O2- or ANG II-induced constriction of arterioles in the distal microcirculation of normotensive hamsters. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Homoploid hybrid expectations

    Science.gov (United States)

    Homoploid hybrid speciation occurs when a stable, fertile, and reproductively isolated lineage results from hybridization between two distinct species without a change in ploidy level. Reproductive isolation between a homoploid hybrid species and its parents is generally attained via chromosomal re...

  19. Identification of heat stress-responsive genes in heat-adapted thermal Agrostis scabra by suppression subtractive hybridization.

    Science.gov (United States)

    Tian, Jiang; Belanger, Faith C; Huang, Bingru

    2009-04-01

    To gain insights into molecular mechanisms of grass tolerance to heat stress, we constructed a suppression subtractive cDNA library to identify heat-responsive genes for a C(3) grass species, thermal Agrostis scabra adapted to heat stress in geothermal areas in Yellowstone National Park. Plants were exposed to 20 degrees C (control) or 35 degrees C for 12d. The SSH analysis was performed with control samples as the driver and heat-stressed samples as the tester. Differentially expressed cDNA fragments were cloned to screen the heat up-regulated library. The SSH analysis identified 120 non-redundant putative heat-responsive cDNAs out of 1180 clones. Genes with homology to known proteins were categorized into six functional groups, with the largest group of genes involved in stress/defense, followed by the group of genes related to protein metabolism. Immunoblot analysis confirmed increases in transcripts of selected genes under heat stress. Transcripts of seven and eight genes were strongly enhanced or induced in shoots and roots, respectively, while two genes were only induced in roots under heat stress. The heat up-regulated genes in thermal A. scabra adapted to long-term heat stress are potential candidate genes for engineering stress-tolerant grasses and for revealing molecular mechanisms of grass adaptation to heat stress.

  20. Photoelastic Stress Analysis by Use of Hybrid Technique and Fringe Phase Shifting Method%利用混合法和相移技术的光弹性应力分析

    Institute of Scientific and Technical Information of China (English)

    白泰铉

    2006-01-01

    Photoelastic fringe patterns for stress analysis are investigated by use of hybrid technique and fringe phase shift method. The first one is a hybrid method which combines the conformal mapping technique and measured data away from the edge of a geometric discontinuity. Photoelastic data are hybridized with complex variable/mapping techniques to calculate photoelastic stress-field around a circular hole or an elliptical hole in plates under uniaxial tensile loading. This method determines full-field stresses in perforated finite tensile plates containing either a circular or an elliptical hole. The second one is a fringe phase shift method to separate isochromatics and isoclinics from photoelastic fringes of a circular disk under diametric compression by use of phase shift method. Digitally determined isochromatics and isoclinics are agreed well with those of manual measurements.

  1. Towards a naturalistic brain-machine interface: hybrid torque and position control allows generalization to novel dynamics.

    Directory of Open Access Journals (Sweden)

    Pratik Y Chhatbar

    Full Text Available Realization of reaching and grasping movements by a paralytic person or an amputee would greatly facilitate her/his activities of daily living. Towards this goal, control of a computer cursor or robotic arm using neural signals has been demonstrated in rodents, non-human primates and humans. This technology is commonly referred to as a Brain-Machine Interface (BMI and is achieved by predictions of kinematic parameters, e.g. position or velocity. However, execution of natural movements, such as swinging baseball bats of different weights at the same speed, requires advanced planning for necessary context-specific forces in addition to kinematic control. Here we show, for the first time, the control of a virtual arm with representative inertial parameters using real-time neural control of torques in non-human primates (M. radiata. We found that neural control of torques leads to ballistic, possibly more naturalistic movements than position control alone, and that adding the influence of position in a hybrid torque-position control changes the feedforward behavior of these BMI movements. In addition, this level of control was achievable utilizing the neural recordings from either contralateral or ipsilateral M1. We also observed changed behavior of hybrid torque-position control under novel external dynamic environments that was comparable to natural movements. Our results demonstrate that inclusion of torque control to drive a neuroprosthetic device gives the user a more direct handle on the movement execution, especially when dealing with novel or changing dynamic environments. We anticipate our results to be a starting point of more sophisticated algorithms for sensorimotor neuroprostheses, eliminating the need of fully automatic kinematic-to-dynamic transformations as currently used by traditional kinematic-based decoders. Thus, we propose that direct control of torques, or other force related variables, should allow for more natural

  2. Is cognitive impairment following early life stress in severe mental disorders based on specific or general cognitive functioning?

    Science.gov (United States)

    Aas, Monica; Steen, Nils E; Agartz, Ingrid; Aminoff, Sofie R; Lorentzen, Steinar; Sundet, Kjetil; Andreassen, Ole A; Melle, Ingrid

    2012-08-15

    Schizophrenia spectrum and bipolar disorder are characterized by high levels of childhood trauma as well as of cognitive dysfunction. Our aim is to investigate the association between these two factors in the largest study in the literature so far. A total of 406 patients with schizophrenia spectrum- or bipolar disorders were recruited from a catchment area based organization in Oslo, Norway. Information about early life stress was obtained using the Childhood Trauma Questionnaire (CTQ). Cognitive function was assessed through a comprehensive and standardized neuropsychological test battery. Physical abuse, sexual abuse and physical neglect were significantly associated with reduced scores on working memory and executive function scales (p=0.04 to pIntelligence (WASI) (p=0.059 to pdisorders, in particular working memory and executive function as well as general cognition. Moreover, these dysfunctions seem to be driven by underlying deficits in general cognitive tasks as measured by the WASI.

  3. [Current status of operations in community general support centers and the correlation of personal traits, work environment and occupational stress].

    Science.gov (United States)

    Yamaguchi, Yoshie

    2010-01-01

    The purpose of this study was to identify the current status of operations at community general support centers which provide coordination for elderly care and the correlation of personal traits, work environment and the occupational stress of the staff. Subjects of the study were 251 staff members of community general support centers. The current status of operations at the community general support centers and the personal traits, work environment, effort-remuneration imbalance model (ERI) and general health questionnaire (GHQ) were surveyed. The initial analysis involved a comparison by a chi-square test on: The effort-remuneration ratio (E/R ratio) of personal traits and work environment, risk of over-commitment (OC), and GHQ score. To explore the correlation between the E/R ratio of the three GHQ groups (low, middle and high score groups) and the OC value, one-way analysis of variance was performed. Out of the four basic functions of the community general support centers, 22.0% of the respondents noted that "establishment of a regional, comprehensive/multi-tiered service network" was functioning, and 50.4% of respondents noted that "comprehensive and continuous care management" was functioning. The average effort score was 15.5 +/- 5.3, approximately double the average value of preceding studies. Significant differences found in GHQ scores were related to working hours (pworking hours of 50 h or more" (OR: 10.38, 95% CI: 2.52-42.70), "Unstable employment" (OR: 2.75, 95% CI: 1.22-6.21) and "Anxiety related to task content" (OR: 17.04, 95% CI: 3.57-81.24). Items observed to have significant correlation with OC value risk factors were: "Weekly working hours of 50 h or more" (OR: 8.04, 95% CI: 1.99-32.41) and "Anxiety related to task content" (OR: 4.60, 95% CI: 2.04-10.37). We conclude that the basic functions of the community general support centers are not presently very functional. The stress levels of the community general support center staff are high and

  4. From epidemiology to daily life : Linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study

    NARCIS (Netherlands)

    Collip, Dina; Wigman, Johanna T. W.; Myin-Germeys, Inez; Jacobs, Nele; Derom, Catherine; Thiery, Evert; Wichers, Marieke; van Os, Jim

    2013-01-01

    Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an

  5. Introduction of Pea DNA Helicase 45 Into Sugarcane (Saccharum spp. Hybrid) Enhances Cell Membrane Thermostability And Upregulation Of Stress-responsive Genes Leads To Abiotic Stress Tolerance.

    Science.gov (United States)

    Augustine, Sruthy Maria; Ashwin Narayan, J; Syamaladevi, Divya P; Appunu, C; Chakravarthi, M; Ravichandran, V; Tuteja, Narendra; Subramonian, N

    2015-05-01

    DNA helicases are motor proteins that play an essential role in nucleic acid metabolism, by providing a duplex-unwinding function. To improve the drought and salinity tolerance of sugarcane, a DEAD-box helicase gene isolated from pea with a constitutive promoter, Port Ubi 2.3 was transformed into the commercial sugarcane variety Co 86032 through Agrobacterium-mediated transformation, and the transgenics were screened for tolerance to soil moisture stress and salinity. The transgene integration was confirmed through polymerase chain reaction, and the V 0 transgenic events showed significantly higher cell membrane thermostability under normal irrigated conditions. The V 1 transgenic events were screened for tolerance to soil moisture stress and exhibited significantly higher cell membrane thermostability, transgene expression, relative water content, gas exchange parameters, chlorophyll content, and photosynthetic efficiency under soil moisture stress compared to wild-type (WT). The overexpression of PDH45 transgenic sugarcane also led to the upregulation of DREB2-induced downstream stress-related genes. The transgenic events demonstrated higher germination ability and better chlorophyll retention than WT under salinity stress. Our results suggest the possibility for development of increased abiotic stress tolerant sugarcane cultivars through overexpression of PDH45 gene. Perhaps this is the first report, which provides evidence for increased drought and salinity tolerance in sugarcane through overexpression of PDH45.

  6. Boron Stress Activates the General Amino Acid Control Mechanism and Inhibits Protein Synthesis

    Science.gov (United States)

    Uluisik, Irem; Kaya, Alaattin; Fomenko, Dmitri E.; Karakaya, Huseyin C.; Carlson, Bradley A.; Gladyshev, Vadim N.; Koc, Ahmet

    2011-01-01

    Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS) of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance. PMID:22114689

  7. Boron stress activates the general amino acid control mechanism and inhibits protein synthesis.

    Directory of Open Access Journals (Sweden)

    Irem Uluisik

    Full Text Available Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance.

  8. Theoretical analysis of the velocity field, stress field and vortex sheet of generalized second order fluid withfractional anomalous diffusion

    Institute of Scientific and Technical Information of China (English)

    徐明瑜; 谭文长

    2001-01-01

    The velocity field of generalized second order fluid with fractional anomalous diffusion caused by a plate moving impulsively in its own plane is investigated and the anomalous diffusion problems of the stress field and vortex sheet caused by this process are studied. Many previous and classical results can be considered as particular cases of this paper, such as the solutions of the fractional diffusion equations obtained by Wyss; the classical Rayleigh' s time-space similarity solution; the relationship between stress field and velocity field obtained by Bagley and co-worker and Podlubny' s results on the fractional motion equation of a plate. In addition, a lot of significant results also are obtained. For example, the necessary condition for causing the vortex sheet is that the time fractional diffusion index β must be greater than that of generalized second order fluid α; the establishment of the vorticity distribution function depends on the time history of the velocity profile at a given point, and the time history can be described by the fractional calculus.

  9. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  10. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  11. Post-traumatic stress disorder symptom burden and gender each affect generalization in a reward- and punishment-learning task.

    Science.gov (United States)

    Radell, Milen L; Beck, Kevin D; Gilbertson, Mark W; Myers, Catherine E

    2017-01-01

    Post-traumatic stress disorder (PTSD) can develop following exposure to a traumatic event. Re-experiencing, which includes intrusive memories or flashbacks of the trauma, is a core symptom cluster of PTSD. From an associative learning perspective, this cluster may be attributed to cues associated with the trauma, which have come to elicit symptoms in a variety of situations encountered in daily life due to a tendency to overgeneralize. Consistent with this, prior studies have indicated that both individuals with clinically diagnosed with PTSD, and those with self-reported symptoms who may not meet full diagnostic criteria, show changes in generalization. Building on prior research, the current study examined whether PTSD symptom burden, but also gender, veteran status, and combat experience-all associated with PTSD vulnerability-modulate learning and generalization in a computer-based task. Participants were presented with stimulus compounds consisting of a foreground and background that could be predictive of reward, punishment or no outcome. Learning was followed by a generalization test where these components were recombined to form novel configurations. An interaction between PTSD symptom burden and gender was found where females with more severe PTSD symptoms showed no evidence of sensitivity to the background. This result is consistent with increased generalization, and may indicate a decrease in the ability to process cue configurations leading to re-experiencing in a variety of situations. Further work is indicated to help elucidate the cognitive processes driving gender differences that may confer vulnerability to PTSD.

  12. Post-traumatic stress disorder symptom burden and gender each affect generalization in a reward- and punishment-learning task

    Science.gov (United States)

    Beck, Kevin D.; Gilbertson, Mark W.; Myers, Catherine E.

    2017-01-01

    Post-traumatic stress disorder (PTSD) can develop following exposure to a traumatic event. Re-experiencing, which includes intrusive memories or flashbacks of the trauma, is a core symptom cluster of PTSD. From an associative learning perspective, this cluster may be attributed to cues associated with the trauma, which have come to elicit symptoms in a variety of situations encountered in daily life due to a tendency to overgeneralize. Consistent with this, prior studies have indicated that both individuals with clinically diagnosed with PTSD, and those with self-reported symptoms who may not meet full diagnostic criteria, show changes in generalization. Building on prior research, the current study examined whether PTSD symptom burden, but also gender, veteran status, and combat experience–all associated with PTSD vulnerability–modulate learning and generalization in a computer-based task. Participants were presented with stimulus compounds consisting of a foreground and background that could be predictive of reward, punishment or no outcome. Learning was followed by a generalization test where these components were recombined to form novel configurations. An interaction between PTSD symptom burden and gender was found where females with more severe PTSD symptoms showed no evidence of sensitivity to the background. This result is consistent with increased generalization, and may indicate a decrease in the ability to process cue configurations leading to re-experiencing in a variety of situations. Further work is indicated to help elucidate the cognitive processes driving gender differences that may confer vulnerability to PTSD. PMID:28196108

  13. [Effect of local sustained stress on general oxygen consumption in belt conveyer workers].

    Science.gov (United States)

    Nakamura, E; Taguchi, S; Fujiki, Y; Kanetaka, A; Nagata, H

    1984-09-01

    The modern mechanization and rationalization of production procedures have recently reduced the intensity of work in most factories. However, it has been pointed out that monotonous inactive work and/or co-operative work can in some sense impose stronger mental and physical stresses which may induce ill health in workers. In this study, assuming the assembly and adjustment of videotape-recorders on a belt conveyor to be representative of monotonous inactive and co-operative work, changes in oxygen consumption, heart rate, blood pressure, body temperature, critical flicker fusion and subjective symptoms of fatigue throughout a workday have been followed for six female workers engaged in this type of work. The main results obtained were as follows: The average oxygen consumption of six workers was 230 ml/min, almost unchanged during the work. The belt conveyor work indicated the metabolic rate of 0.3 in terms of relative metabolic rate. The net daily energy expenditure due to the work was only about 100 kcal. The average heart rate during assembly and adjustment were respectively, about 1.4 and 1.2 times the average heart rate at rest. The blood pressure and the rate of oxygen removal increased slightly as the work progressed in assembly work, but did not increase at all in adjustment work. The critical flicker fusion and body temperature showed little change during the work.

  14. A master-slave parallel hybrid multi-objective evolutionary algorithm for groundwater remediation design under general hydrogeological conditions

    Science.gov (United States)

    Wu, J.; Yang, Y.; Luo, Q.; Wu, J.

    2012-12-01

    This study presents a new hybrid multi-objective evolutionary algorithm, the niched Pareto tabu search combined with a genetic algorithm (NPTSGA), whereby the global search ability of niched Pareto tabu search (NPTS) is improved by the diversification of candidate solutions arose from the evolving nondominated sorting genetic algorithm II (NSGA-II) population. Also, the NPTSGA coupled with the commonly used groundwater flow and transport codes, MODFLOW and MT3DMS, is developed for multi-objective optimal design of groundwater remediation systems. The proposed methodology is then applied to a large-scale field groundwater remediation system for cleanup of large trichloroethylene (TCE) plume at the Massachusetts Military Reservation (MMR) in Cape Cod, Massachusetts. Furthermore, a master-slave (MS) parallelization scheme based on the Message Passing Interface (MPI) is incorporated into the NPTSGA to implement objective function evaluations in distributed processor environment, which can greatly improve the efficiency of the NPTSGA in finding Pareto-optimal solutions to the real-world application. This study shows that the MS parallel NPTSGA in comparison with the original NPTS and NSGA-II can balance the tradeoff between diversity and optimality of solutions during the search process and is an efficient and effective tool for optimizing the multi-objective design of groundwater remediation systems under complicated hydrogeologic conditions.

  15. Suppression Subtractive Hybridization Analysis of Genes Regulated by Application of Exogenous Abscisic Acid in Pepper Plant (Capsicum annuum L. Leaves under Chilling Stress.

    Directory of Open Access Journals (Sweden)

    Wei-Li Guo

    Full Text Available Low temperature is one of the major factors limiting pepper (Capsicum annuum L. production during winter and early spring in non-tropical regions. Application of exogenous abscisic acid (ABA effectively alleviates the symptoms of chilling injury, such as wilting and formation of necrotic lesions on pepper leaves; however, the underlying molecular mechanism is not understood. The aim of this study was to identify genes that are differentially up- or downregulated in ABA-pretreated hot pepper seedlings incubated at 6°C for 48 h, using a suppression subtractive hybridization (SSH method. A total of 235 high-quality ESTs were isolated, clustered and assembled into a collection of 73 unigenes including 18 contigs and 55 singletons. A total of 37 unigenes (50.68% showed similarities to genes with known functions in the non-redundant database; the other 36 unigenes (49.32% showed low similarities or unknown functions. Gene ontology analysis revealed that the 37 unigenes could be classified into nine functional categories. The expression profiles of 18 selected genes were analyzed using quantitative RT-PCR; the expression levels of 10 of these genes were at least two-fold higher in the ABA-pretreated seedlings under chilling stress than water-pretreated (control plants under chilling stress. In contrast, the other eight genes were downregulated in ABA-pretreated seedlings under chilling stress, with expression levels that were one-third or less of the levels observed in control seedlings under chilling stress. These results suggest that ABA can positively and negatively regulate genes in pepper plants under chilling stress.

  16. Suppression Subtractive Hybridization Analysis of Genes Regulated by Application of Exogenous Abscisic Acid in Pepper Plant (Capsicum annuum L.) Leaves under Chilling Stress.

    Science.gov (United States)

    Guo, Wei-Li; Chen, Ru-Gang; Gong, Zhen-Hui; Yin, Yan-Xu; Li, Da-Wei

    2013-01-01

    Low temperature is one of the major factors limiting pepper (Capsicum annuum L.) production during winter and early spring in non-tropical regions. Application of exogenous abscisic acid (ABA) effectively alleviates the symptoms of chilling injury, such as wilting and formation of necrotic lesions on pepper leaves; however, the underlying molecular mechanism is not understood. The aim of this study was to identify genes that are differentially up- or downregulated in ABA-pretreated hot pepper seedlings incubated at 6°C for 48 h, using a suppression subtractive hybridization (SSH) method. A total of 235 high-quality ESTs were isolated, clustered and assembled into a collection of 73 unigenes including 18 contigs and 55 singletons. A total of 37 unigenes (50.68%) showed similarities to genes with known functions in the non-redundant database; the other 36 unigenes (49.32%) showed low similarities or unknown functions. Gene ontology analysis revealed that the 37 unigenes could be classified into nine functional categories. The expression profiles of 18 selected genes were analyzed using quantitative RT-PCR; the expression levels of 10 of these genes were at least two-fold higher in the ABA-pretreated seedlings under chilling stress than water-pretreated (control) plants under chilling stress. In contrast, the other eight genes were downregulated in ABA-pretreated seedlings under chilling stress, with expression levels that were one-third or less of the levels observed in control seedlings under chilling stress. These results suggest that ABA can positively and negatively regulate genes in pepper plants under chilling stress.

  17. GhHyPRP4, a cotton gene encoding putative hybrid proline-rich protein, is preferentially expressed in leaves and involved in plant response to cold stress

    Institute of Scientific and Technical Information of China (English)

    Gengqing Huang; Siying Gong; Wenliang Xu; Peng Li; Dejing Zhang; Lixia Qin; Wen Li; Xuebao Li

    2011-01-01

    Plant hybrid proline-rich proteins (HyPRPs) usually consist of an N-terminal signal peptide, a central prolinerich domain, and a conserved eight-cysteine motif C-terminal domain. In this study, one gene (designated as GhHyPRP4) encoding putative HyPRP was isolated from cotton cDNA library. Northern blot and quantitative reverse transcriptase-polymerase chain reaction analyses revealed that GhHyPRP4 was preferentially expressed in leaves. Under cold stress, GhHyPRP4 expression was significantly up-regulated in leaves of cotton seedlings.Using the genome walking approach, a promoter fragment of GhHyPRP4 gene was isolated from cotton genome.GUS (β-glucuronidase) gene driven by GhHyPRP4 promoter was specifically expressed in leaves and cotyledons of the transgenic 4rabidopsis thaliana. Furthermore,GUS expression in leaves was remarkably induced by cold stress. Overexpression of GhHyPRP4 in yeast (Schizosaccharomyces pombe) significantly enhanced the cell survival rate upon treatment under -20℃ for 60 h.These data suggested that GhHyPRP4 may be involved in plant response to cold stress during seedling development of cotton.

  18. Investigating the Subsurface Stress Field based on Hybrid Earthquake Focal Mechanisms: Examples from the Fort Worth Basin, Texas

    Science.gov (United States)

    Jia, S.; Eaton, D. W. S.; Wong, R.

    2016-12-01

    Knowledge of in situ stress state and rock failure mechanisms is key for modelling and predicting subsurface material behavior. Earthquake focal mechanisms are extensively used for in situ stress determination, as reflected by their widespread use for the World Stress Map project. The rupture process emits radiated seismic energy, from which equivalent force couples acting a point (moment tensor) may be determined. Inversion methods, including formal estimates of uncertainty, have been developed to estimate stress parameters from moment-tensor observations. Methods that have been developed so far are based on the assumptions that the source mechanism is purely double-couple (DC) and the direction of the slip vector is parallel to the shear stress acting on the fault plane (Wallace-Bott hypothesis). However, this is not always the case, especially for microseismic events that occur during hydraulic fracturing, in which case injected fluids can significantly elevate the pore pressure. In the case of shear-tensile failure, the slip vector may deviate from the fault plane due to complex failure mechanisms surrounding an injection site. To eliminate this restriction and better analyze stress state during injection, a new approach is developed under the assumption that the slip vector is parallel to the direction of the traction vector acting on a fault plane. The microseismic data analyzed in this study were acquired in 2010 during a multi-well completion in the Fort Worth Basin. The dataset contains 7444 microseismic events with full moment-tensor solutions. Results of our analysis, which utilizes events with the best resolved solutions, reveal that the shear-tensile stress inversion approach improves the determination of failure plane and stress state.

  19. Stress

    OpenAIRE

    Jensen, Line Skov; Lova, Lotte; Hansen, Zandra Kulikovsky; Schønemann, Emilie; Larsen, Line Lyngby; Colberg Olsen, Maria Sophia; Juhl, Nadja; Magnussen, Bogi Roin

    2012-01-01

    Stress er en tilstand som er meget omdiskuteret i samfundet, og dette besværliggør i en vis grad konkretiseringen af mulige løsningsforslag i bestræbelsen på at forebygge den såkaldte folkesygdom. Hovedkonklusionen er, at selv om der bliver gjort meget for at forebygge, er der ikke meget der aktivt kan sættes i værk for at reducere antallet af stressramte, før en fælles forståelse af stressårsager og effektiv stresshåndtering er fremlagt. Problemformuleringen er besvaret gennem en undersø...

  20. A new formulation of hybrid/mixed finite element

    Science.gov (United States)

    Pian, T. H. H.; Kang, D.; Chen, D.-P.

    1983-01-01

    A new formulation of finite element method is accomplished by the Hellinger-Reissner principle for which the stress equilibrium conditions are not introduced initially but are brought-in through the use of additional internal displacement parameters. The method can lead to the same result as the assumed stress hybrid model. However, it is more general and more flexible. The use of natural coordinates for stress assumptions leads to elements which are less sensitive to the choice of reference coordinates. Numerical solutions by 3-D solid element indicate that more efficient elements can be constructed by assumed stresses which only partially satisfy the equilibrium conditions.

  1. Experiences of possession and paranormal phenomena among women in the general population: are they related to traumatic stress and dissociation?

    Science.gov (United States)

    Sar, Vedat; Alioğlu, Firdevs; Akyüz, Gamze

    2014-01-01

    This study sought to determine the prevalence of experiences of possession and paranormal phenomena (PNP) in the general population and their possible relations to each other and to traumatic stress and dissociation. The study was conducted on a representative female sample recruited from a town in central eastern Turkey. The Dissociative Disorders Interview Schedule, the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interviews for DSM-IV Axis-I and Personality Disorders, and the Childhood Abuse and Neglect Questionnaire were administered to 628 women. Of these, 127 (20.2%) women reported at least 1 type of PNP and 13 (2.1%) women reported possession. Women with a dissociative disorder reported all types of possession and PNP (except telepathy) more frequently than those without. Whereas women with a trauma history in childhood and adulthood or PTSD reported possession more frequently than those without, PNP were associated with childhood trauma only. Factor analysis yielded 4 dimensions: possession by and/or contact with nonhuman entities, extrasensory communications, possession by a human entity, and precognition. These factors correlated with number of secondary features of dissociative identity disorder and Schneiderian symptoms. Latent class analysis identified 3 groups. The most traumatized group, with predominantly dissociative and trauma-related disorders, had the highest scores on all factors. Notwithstanding their presence in healthy individuals, possession and PNP were associated with trauma and dissociation in a subgroup of affected participants. Both types of experience seem to be normal human capacities of experiencing that may be involved in response to traumatic stress. Given the small numbers, this study should be considered preliminary.

  2. A tailored relocation stress intervention programme for family caregivers of patients transferred from a surgical intensive care unit to a general ward.

    Science.gov (United States)

    Lee, Seul; Oh, HyunSoo; Suh, YeonOk; Seo, WhaSook

    2017-03-01

    To develop and examine a relocation stress intervention programme tailored for the family caregivers of patients scheduled for transfer from a surgical intensive care unit to a general ward. Family relocation stress syndrome has been reported to be similar to that exhibited by patients, and investigators have emphasised that nurses should make special efforts to relieve family relocation stress to maximise positive contributions to the well-being of patients by family caregivers. A nonequivalent control group, nonsynchronised pretest-post-test design was adopted. The study subjects were 60 family caregivers of patients with neurosurgical or general surgical conditions in the surgical intensive care unit of a university hospital located in Incheon, South Korea. Relocation stress and family burden were evaluated at three times, that is before intervention, immediately after transfer and four to five days after transfer. This relocation stress intervention programme was developed for the family caregivers based on disease characteristics and relocation-related needs. In the experimental group, relocation stress levels significantly and continuously decreased after intervention, whereas in the control group, a slight nonsignificant trend was observed. Family burden levels in the control group increased significantly after transfer, whereas burden levels in the experimental group increased only marginally and nonsignificantly. No significant between-group differences in relocation stress or family burden levels were observed after intervention. Relocation stress levels of family caregivers were significantly decreased after intervention in the experimental group, which indicates that the devised family relocation stress intervention programme effectively alleviated family relocation stress. The devised intervention programme, which was tailored to disease characteristics and relocation-related needs, may enhance the practicality and efficacy of relocation stress

  3. Associations among depressive symptoms, childhood abuse, neuroticism, and adult stressful life events in the general adult population

    Directory of Open Access Journals (Sweden)

    Ono K

    2017-02-01

    Full Text Available Kotaro Ono,1 Yoshikazu Takaesu,1 Yukiei Nakai,2 Akiyoshi Shimura,1 Yasuyuki Ono,1 Akiko Murakoshi,1 Yasunori Matsumoto,1 Hajime Tanabe,3 Ichiro Kusumi,2 Takeshi Inoue1 1Department of Psychiatry, Tokyo Medical University, Tokyo, 2Department of Psychiatry, Hokkaido University Graduate School of Medicine, Hokkaido, 3Department of Clinical Human Sciences, Graduate school of Humanities and Social Sciences, Shizuoka University, Shizuoka, Japan Background: Recent studies have suggested that the interactions among several factors affect the onset, progression, and prognosis of major depressive disorder. This study investigated how childhood abuse, neuroticism, and adult stressful life events interact with one another and affect depressive symptoms in the general adult population. Subjects and methods: A total of 413 participants from the nonclinical general adult population completed the Patient Health Questionnaire-9, the Child Abuse and Trauma Scale, the neuroticism subscale of the shortened Eysenck Personality Questionnaire – Revised, and the Life Experiences Survey, which are self-report scales. Structural equation modeling (Mplus version 7.3 and single and multiple regressions were used to analyze the data. Results: Childhood abuse, neuroticism, and negative evaluation of life events increased the severity of the depressive symptoms directly. Childhood abuse also indirectly increased the negative appraisal of life events and the severity of the depressive symptoms through enhanced neuroticism in the structural equation modeling. Limitations: There was recall bias in this study. The causal relationship was not clear because this study was conducted using a cross-sectional design. Conclusion: This study suggested that neuroticism is the mediating factor for the two effects of childhood abuse on adulthood depressive symptoms and negative evaluation of life events. Childhood abuse directly and indirectly predicted the severity of depressive symptoms

  4. The Generalized Hybrid Averaging Operator and its Application in Decision Making // La media generalizada híbrida y su aplicación en la toma de decisiones

    Directory of Open Access Journals (Sweden)

    Casanovas Ramón, Montserrat

    2010-01-01

    Full Text Available We present the generalized hybrid averaging (GHA operator. It is a new aggregation operator that generalizes the hybrid averaging (HA operator by using the generalized mean. Thus, we are able to generalize a wide range of mean operators such as the HA, the hybrid geometric averaging (HGA, the hybrid quadratic averaging (HQA, the generalized ordered weighted averaging (GOWA operator and the weighted generalized mean (WGM. A key feature in this aggregation operator is that it is able to deal with the weighted average and the ordered weighted averaging (OWA operator in the same formulation. We further generalize the GHA by using quasi-arithmetic means obtaining the quasi-arithmetic hybrid averaging (Quasi-HA operator. We conclude the paper with an example of the new approach in a financial decision making problem. // En este artículo se presenta el operador de medias generalizadas híbridas. Es un nuevo operador de agregación que generaliza la media híbrida utilizando la media generalizada. Debido a esto, se puede generalizar una amplia gama de operadores de medias, como la media híbrida, la media geométrica híbrida, la media cuadrática híbrida, la media ponderada ordenada generalizada y la media ponderada generalizada. Un aspecto fundamental en este operador de agregación es la posibilidad de utilizar medias ponderadas y medias ponderadas ordenadas en la misma formulación. A continuación, se presenta una generalización mayor mediante la utilización de medias cuasi-aritméticas, obteniendo así la media cuasi-aritmética híbrida. El trabajo termina con un ejemplo de aplicación del nuevo modelo en un problema de toma de decisiones financieras.

  5. Associations among depressive symptoms, childhood abuse, neuroticism, and adult stressful life events in the general adult population

    Science.gov (United States)

    Ono, Kotaro; Takaesu, Yoshikazu; Nakai, Yukiei; Shimura, Akiyoshi; Ono, Yasuyuki; Murakoshi, Akiko; Matsumoto, Yasunori; Tanabe, Hajime; Kusumi, Ichiro; Inoue, Takeshi

    2017-01-01

    Background Recent studies have suggested that the interactions among several factors affect the onset, progression, and prognosis of major depressive disorder. This study investigated how childhood abuse, neuroticism, and adult stressful life events interact with one another and affect depressive symptoms in the general adult population. Subjects and methods A total of 413 participants from the nonclinical general adult population completed the Patient Health Questionnaire-9, the Child Abuse and Trauma Scale, the neuroticism subscale of the shortened Eysenck Personality Questionnaire – Revised, and the Life Experiences Survey, which are self-report scales. Structural equation modeling (Mplus version 7.3) and single and multiple regressions were used to analyze the data. Results Childhood abuse, neuroticism, and negative evaluation of life events increased the severity of the depressive symptoms directly. Childhood abuse also indirectly increased the negative appraisal of life events and the severity of the depressive symptoms through enhanced neuroticism in the structural equation modeling. Limitations There was recall bias in this study. The causal relationship was not clear because this study was conducted using a cross-sectional design. Conclusion This study suggested that neuroticism is the mediating factor for the two effects of childhood abuse on adulthood depressive symptoms and negative evaluation of life events. Childhood abuse directly and indirectly predicted the severity of depressive symptoms. PMID:28243100

  6. Improvement in Stress, General Self-Efficacy, and Health Related Quality of Life following Patient Education for Patients with Neuroendocrine Tumors: A Pilot Study.

    Science.gov (United States)

    Haugland, Trude; Veenstra, Marijke; Vatn, Morten H; Wahl, Astrid K

    2013-01-01

    The purpose of the study was to evaluate changes in general self-efficacy, health related quality of life (HRQoL), and stress among patients with neuroendocrine tumors (NET) following a multidisciplinary educational intervention. Forty-one patients were enrolled in this exploratory pilot study. A total of 37 patients completed the full 26-week intervention based on the principles of self-efficacy. General self-efficacy was measured by the General Self-Efficacy Scale, HRQoL was measured with the SF-36, and stress was measured with the Impact of Event Scale. Mixed effect models were used to evaluate changes in general self-efficacy, mental and physical components of HRQoL, and stress adjusting for demographic and clinical variables. Results showed significant improvements in patients' general self-efficacy (β = 0.71; P stress (β = -2.10, P = 0.008). Findings suggest that patients with NET have the capacity to improve their ability to cope with their disease, problem-solve, improve their physical status, and reduce their stress following an educational intervention based on the principles of self-efficacy. These preliminary data provide a basis for future randomized controlled trials to test interventions to improve HRQoL for patients with NET.

  7. Improvement in Stress, General Self-Efficacy, and Health Related Quality of Life following Patient Education for Patients with Neuroendocrine Tumors: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Trude Haugland

    2013-01-01

    Full Text Available The purpose of the study was to evaluate changes in general self-efficacy, health related quality of life (HRQoL, and stress among patients with neuroendocrine tumors (NET following a multidisciplinary educational intervention. Forty-one patients were enrolled in this exploratory pilot study. A total of 37 patients completed the full 26-week intervention based on the principles of self-efficacy. General self-efficacy was measured by the General Self-Efficacy Scale, HRQoL was measured with the SF-36, and stress was measured with the Impact of Event Scale. Mixed effect models were used to evaluate changes in general self-efficacy, mental and physical components of HRQoL, and stress adjusting for demographic and clinical variables. Results showed significant improvements in patients’ general self-efficacy (β = 0.71; P<0.05, physical component scores of HRQoL (β = 3.09; P<0.01, and stress (β=-2.10, P=0.008. Findings suggest that patients with NET have the capacity to improve their ability to cope with their disease, problem-solve, improve their physical status, and reduce their stress following an educational intervention based on the principles of self-efficacy. These preliminary data provide a basis for future randomized controlled trials to test interventions to improve HRQoL for patients with NET.

  8. Study on Stress Concentrations in an Intraply Hybrid Composite Sheet%层内混杂复合材料应力集中问题的研究

    Institute of Scientific and Technical Information of China (English)

    曾庆敦; 黄小清; 林雪慧

    2001-01-01

    提出了一种合理、简便、精确的修正的剪滞模型,基于此模型,分析了受拉伸的层内混杂复合材料中某些纤维断裂后的应力重分布,结果表明,求得的应力集中因子与Fukuda和Chou的结果相当接近,从而证实了本文模型和方法的合理性和正确性,%A reasonably, simply and accurately modified shear_lag model was proposed. Based on the model, the stress redistributions due to the failure of some fibers in an intraply hybrid composite under tension were analyzed. The results show that the present calculating stress concentration factors very coincide with Fukuda and Chou's results, thus verifying the reasonableness and correctness of the present model and methods.

  9. 一种基于H-R变分的杂交广义元方法%A Hybrid Generalized Element Method Based on H-R Variational Principle

    Institute of Scientific and Technical Information of China (English)

    杨森森; 马永其; 冯伟

    2013-01-01

    Combining Hellinger-Reissner variational principle and the way of constructing displacement interpolation function of generalized finite element method to construct stress field and displacement field independently, through the suitable stress field could get a more precise stress value of node conveniently, and in the same time to increase the order of displacement function without increasing the number of element's nodes, in this way a more accurate result was got. This method combines the above two methods of flexibility of constructing the stress field and displacement field, meanwhile, using less memory and equations on the same condition compared with some other methods, and the results also show that of efficiency and higher presicion.%基于Hellinger-Reissner变分原理,通过构造合适的应力场函数使其能更方便和更准确地得到节点上的应力值,同时结合广义有限元构造广义位移插值的方法,在不提高单元节点数目的前提下提高位移场函数的阶次,从而提高其求解精度.这种方法能同时灵活地构造应力场和位移场,在同等精度条件下能占用较少内存和求解更少的方程数目,计算结果也显示了这种方法的有效性和很高的计算精度.

  10. The LovK-LovR two-component system is a regulator of the general stress pathway in Caulobacter crescentus.

    Science.gov (United States)

    Foreman, Robert; Fiebig, Aretha; Crosson, Sean

    2012-06-01

    A conserved set of regulators control the general stress response in Caulobacter crescentus, including σ(T), its anti-σ factor NepR, the anti-anti-σ factor PhyR, and the transmembrane sensor kinase PhyK. We report that the soluble histidine kinase LovK and the single-domain response regulator LovR also function within the C. crescentus general stress pathway. Our genetic data support a model in which LovK-LovR functions upstream of σ(T) by controlling the phosphorylation state and thus anti-anti-σ activity of PhyR. Transcription of lovK and lovR is independently activated by stress through a mechanism that requires sigT and phyR. Conversely, lovK and lovR function together to repress transcription of the general stress regulon. Concordant with a functional role of the LovK-LovR two-component system as a negative regulator of the general stress pathway, lovK-lovR-null mutants exhibit increased cell survival after osmotic stress, while coordinate overexpression of lovK and lovR attenuates cell survival relative to that of the wild type. Notably, lovK can complement the transcriptional and cell survival defects of a phyK-null mutant when lovR is deleted. Moreover, in this same genetic background, σ(T)-dependent transcription is activated in response to osmotic stress. This result suggests that flavin-binding LOV (light, oxygen, or voltage) histidine kinases are competent to perceive cytoplasmic signals in addition to the environmental signal blue light. We conclude that the PhyK-PhyR and LovK-LovR two-component signaling systems coordinately regulate stress physiology in C. crescentus.

  11. Using the stress function in the flow of generalized Newtonian fluids through conduits with non-circular or multiply connected cross sections

    CERN Document Server

    Sochi, Taha

    2015-01-01

    We investigate the possibility that the spatial dependency of stress in generalized Newtonian flow systems is a function of the applied pressure field and the conduit geometry but not of the fluid rheology. This possibility is well established for the case of a one-dimensional flow through simply connected regions, specifically tubes of circular uniform cross sections and plane thin slits. If it can also be established for the more general case of generalized Newtonian flow through non-circular or multiply connected geometries, such as the two-dimensional flow through conduits of rectangular or elliptical cross sections or the flow through annular circular pipes, then analytical or semi-analytical or highly accurate numerical solutions; regarding stress, rate of strain, velocity profile and volumetric flow rate; for these geometries can be obtained from the stress function, which can be easily obtained from the Newtonian case, in combination with the constitutive rheological relation for the particular non-Ne...

  12. Stress-energy tensor correlators in N-dimensional hot flat spaces via the generalized zeta-function method

    Science.gov (United States)

    Cho, H. T.; Hu, B. L.

    2012-09-01

    We calculate the expectation values of the stress-energy bitensor defined at two different spacetime points x, x‧ of a massless, minimally coupled scalar field with respect to a quantum state at finite temperature T in a flat N-dimensional spacetime by means of the generalized zeta-function method. These correlators, also known as the noise kernels, give the fluctuations of energy and momentum density of a quantum field which are essential for the investigation of the physical effects of negative energy density in certain spacetimes or quantum states. They also act as the sources of the Einstein-Langevin equations in stochastic gravity which one can solve for the dynamics of metric fluctuations as in spacetime foams. In terms of constitutions these correlators are one rung above (in the sense of the correlation—BBGKY or Schwinger-Dyson—hierarchies) the mean (vacuum and thermal expectation) values of the stress-energy tensor which drive the semiclassical Einstein equation in semiclassical gravity. The low- and the high-temperature expansions of these correlators are also given here: at low temperatures, the leading order temperature dependence goes like TN while at high temperatures they have a T2 dependence with the subleading terms exponentially suppressed by e-T. We also discuss the singular behavior of the correlators in the x‧ → x coincident limit as was done before for massless conformal quantum fields. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker’s 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’.

  13. Continuous postoperative infusion of remifentanil inhibits the stress responses to tracheal extubation of patients under general anesthesia

    Directory of Open Access Journals (Sweden)

    Zhao G

    2017-04-01

    Full Text Available Guoliang Zhao, Xiaoyue Yin, Ya Li, Jianlin Shao Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, Kunming, People’s Republic of China Purpose: The study aimed to assess the combined effects of parecoxib with three different doses of remifentanil and its effect on the stress and cough responses following tracheal extubation under general anesthesia.Methods: A total of 120 patients with American Society of Anesthesiologists (ASA scores of I or II, undergoing selective thyroidectomy with total intravenous anesthesia (propofol-remifentanil and tracheal intubation, were randomly allocated to be treated with an intravenous injection of parecoxib and a continuous infusion of remifentanil at 0.1 μg/kg/min (R1, 0.2 μg/kg/min (R2, 0.3 μg/kg/min (R3, or an isotonic saline injection (the control group. Hemodynamic vital signs, emergence time, extubation time, sedation-agitation scale (SAS score, pain visual analog scale (VAS score, occurrence of coughing, and side effects were recorded before surgery and during the peri-extubation period. The vital signs included blood pressure (BP, heart rate (HR, respiratory rate (R, and peripheral arterial oxygen saturation (SPO2.Results: BP, HR, the occurrence rate of coughing, and extubation awareness decreased with the dose of remifentanil, and the differences among the groups were significant (P < 0.05. Emergence and extubation time increased with the dose of remifentanil, and the differences among the groups were significant (P < 0.05. The occurrence rates of respiratory depression and bradycardia in group R3 were significantly higher than those in other groups (P < 0.05. SAS and VAS were lowest in group R3, and the differences among the groups were significant (P < 0.05. BP, HR, SAS, and VAS increased with time in the remifentanil groups.Conclusion: The combined use of parecoxib and a moderate dose of remifentanil can effectively suppress the stress and coughing

  14. Comparison between general anesthesia and spinal anesthesia in attenuation of stress response in laparoscopic cholecystectomy: A randomized prospective trial

    Directory of Open Access Journals (Sweden)

    Writuparna Das

    2015-01-01

    Full Text Available Background: Laparoscopy though minimally invasive produces significant hemodynamic surge and neuroendocrine stress response. Though general anesthesia (GA is the conventional technique, now-a-days, regional anesthesia has been accepted for laparoscopic diagnostic procedures, and its use is also being extended to laparoscopic surgeries. Objective: The aim was to compare the hemodynamic surge and neuroendocrine stress response during laparoscopic cholecystectomy (LC under GA and spinal anesthesia (SA in American Society of Anesthesiologists (ASA PS 1 patients. Materials and Methods: Thirty ASA physical status I patients, aged 18-65 years were randomly allocated into two equal groups of 15 each. Group A received GA with controlled ventilation. Patients were preoxygenated for 5 min with 100/5 oxygen, premedicated with midazolam 0.03 mg/kg intravenous (i.v, fentanyl 2 mcg/kg i.v; induction was done with thiopentone 3-5 mg/kg i.v; intubation was achieved after muscle relaxation with 0.5 mg/kg atracurium besylate i.v. Anesthesia was maintained with 1-2% sevoflurane and N2O:O2 (60:40 and intermittent i.v injection of atracurium besylate. Group B SA with 0.5% hyperbaric bupivacaine and 25 μg fentanyl along with local anesthetic instillation in the subdiaphragmatic space. Mean arterial pressure, heart rate (HR, oxygen saturation, end tidal carbon-dioxide were recorded. Venous blood was collected for cortisol assay before induction and 30 min after pneumoperitoneum. All data were collected in Microsoft excel sheet and statistically analyzed using SPSS software version 16 (SPSS Inc., Chicago, IL, USA. All numerical data were analyzed using Student′s t-test and paired t-test. Any value <0.05 was taken as significant. Results: Mean arterial pressure and mean HR and postpneumoperitoneum cortisol level were lower in group B than group A though the difference was not statistically significant in hemodynamic parameters but significant in case of cortisol

  15. Final Governing Equation of Plane Elasticity of Icosahedral Quasicrystals and General Solution Based on Stress Potential Function

    Institute of Scientific and Technical Information of China (English)

    LI Lian-He; FAN Tian-You

    2006-01-01

    @@ The stress potential function theory for plane elasticity of icosahedral quasicrystals is developed. By introducing stress functions, huge numbers of basic equations involving elasticity of icosahedral quasicrystals are reduced to a single partial differential equation of the 12th order.

  16. Application of simplified model for the analysis of a novel battery used in General Motors' Precept hybrid electric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Verbrugge, M.W. [General Motors Corp., Troy, MI (United States). Advanced Technology Vehicles

    2000-07-01

    The challenges facing the integration of a battery module into an electric vehicle (EV) was discussed and some simple approaches to address these challenges were proposed. The cost of EV batteries inhibits large-scale commercialization. Other challenges include the current, potential and state of charge (SOC) as well as the thermal system requirements and design. One solution is to develop hybrid electric vehicles (HEV) which would mean the battery size could be significantly reduced because the engine would supply most of the needed energy to power the vehicle. The author suggested a simple mathematical method to analyze HEV batteries and conduct trade-offs in order to optimize a car's energy storage, high voltage and thermal systems. A newly developed HEV nickel-metal hydride battery system which is found in General Motors' Precept HEV was used to test the approach. The analysis is partly based on understanding how the past charges and discharges influence the apparent hysteresis characterizing the SOC versus open-circuit potential relationship. The method does not address the temperature deviations with the battery pack. The difference between liquid and air cooling was also determined. It is hoped that battery suppliers will adopt this method to speed the advancement of this sector of development. refs., tabs., figs.

  17. Evolution of a hybrid micro-macro entangled state of the qubit-oscillator system via the generalized rotating wave approximation

    Science.gov (United States)

    Chakrabarti, R.; Yogesh, V.

    2016-04-01

    We study the evolution of the hybrid entangled states in a bipartite (ultra) strongly coupled qubit-oscillator system. Using the generalized rotating wave approximation the reduced density matrices of the qubit and the oscillator are obtained. The reduced density matrix of the oscillator yields the phase space quasi probability distributions such as the diagonal P-representation, the Wigner W-distribution and the Husimi Q-function. In the strong coupling regime the Q-function evolves to uniformly separated macroscopically distinct Gaussian peaks representing ‘kitten’ states at certain specified times that depend on multiple time scales present in the interacting system. The ultrastrong coupling strength of the interaction triggers appearance of a large number of modes that quickly develop a randomization of their phase relationships. A stochastic averaging of the dynamical quantities sets in, and leads to the decoherence of the system. The delocalization in the phase space of the oscillator is studied by using the Wehrl entropy. The negativity of the W-distribution reflects the departure of the oscillator from the classical states, and allows us to study the underlying differences between various information-theoretic measures such as the Wehrl entropy and the Wigner entropy. Other features of nonclassicality such as the existence of the squeezed states and appearance of negative values of the Mandel parameter are realized during the course of evolution of the bipartite system. In the parametric regime studied here these properties do not survive in the time-averaged limit.

  18. Nonlinear electronic excitations in crystalline solids using meta-generalized gradient approximation and hybrid functional in time-dependent density functional theory

    Science.gov (United States)

    Sato, Shunsuke A.; Taniguchi, Yasutaka; Shinohara, Yasushi; Yabana, Kazuhiro

    2015-12-01

    We develop methods to calculate electron dynamics in crystalline solids in real-time time-dependent density functional theory employing exchange-correlation potentials which reproduce band gap energies of dielectrics; a meta-generalized gradient approximation was proposed by Tran and Blaha [Phys. Rev. Lett. 102, 226401 (2009)] (TBm-BJ) and a hybrid functional was proposed by Heyd, Scuseria, and Ernzerhof [J. Chem. Phys. 118, 8207 (2003)] (HSE). In time evolution calculations employing the TB-mBJ potential, we have found it necessary to adopt the predictor-corrector step for a stable time evolution. We have developed a method to evaluate electronic excitation energy without referring to the energy functional which is unknown for the TB-mBJ potential. For the HSE functional, we have developed a method for the operation of the Fock-like term in Fourier space to facilitate efficient use of massive parallel computers equipped with graphic processing units. We compare electronic excitations in silicon and germanium induced by femtosecond laser pulses using the TB-mBJ, HSE, and a simple local density approximation (LDA). At low laser intensities, electronic excitations are found to be sensitive to the band gap energy: they are close to each other using TB-mBJ and HSE and are much smaller in LDA. At high laser intensities close to the damage threshold, electronic excitation energies do not differ much among the three cases.

  19. Nonlinear electronic excitations in crystalline solids using meta-generalized gradient approximation and hybrid functional in time-dependent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Shunsuke A. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Taniguchi, Yasutaka [Center for Computational Science, University of Tsukuba, Tsukuba 305-8571 (Japan); Department of Medical and General Sciences, Nihon Institute of Medical Science, 1276 Shimogawara, Moroyama-Machi, Iruma-Gun, Saitama 350-0435 (Japan); Shinohara, Yasushi [Max Planck Institute of Microstructure Physics, 06120 Halle (Germany); Yabana, Kazuhiro [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571 (Japan); Center for Computational Science, University of Tsukuba, Tsukuba 305-8571 (Japan)

    2015-12-14

    We develop methods to calculate electron dynamics in crystalline solids in real-time time-dependent density functional theory employing exchange-correlation potentials which reproduce band gap energies of dielectrics; a meta-generalized gradient approximation was proposed by Tran and Blaha [Phys. Rev. Lett. 102, 226401 (2009)] (TBm-BJ) and a hybrid functional was proposed by Heyd, Scuseria, and Ernzerhof [J. Chem. Phys. 118, 8207 (2003)] (HSE). In time evolution calculations employing the TB-mBJ potential, we have found it necessary to adopt the predictor-corrector step for a stable time evolution. We have developed a method to evaluate electronic excitation energy without referring to the energy functional which is unknown for the TB-mBJ potential. For the HSE functional, we have developed a method for the operation of the Fock-like term in Fourier space to facilitate efficient use of massive parallel computers equipped with graphic processing units. We compare electronic excitations in silicon and germanium induced by femtosecond laser pulses using the TB-mBJ, HSE, and a simple local density approximation (LDA). At low laser intensities, electronic excitations are found to be sensitive to the band gap energy: they are close to each other using TB-mBJ and HSE and are much smaller in LDA. At high laser intensities close to the damage threshold, electronic excitation energies do not differ much among the three cases.

  20. Effort-reward and work-life imbalance, general stress and burnout among employees of a large public hospital in Switzerland.

    Science.gov (United States)

    Hämmig, Oliver; Brauchli, Rebecca; Bauer, Georg F

    2012-05-31

    Effort-reward imbalance (ERI) and work-life imbalance (WLI) are recognised risk factors for work stress and burnout but have not been investigated conjointly so far and compared with each other in this regard. The present cross-sectional study provides initial evidence by studying associations of ERI and WLI with general stress and burnout simultaneously. The study was based on survey data collected in 2007 among the personnel of a large public hospital in the canton of Zurich covering a random sample of 502 employees of all professions and positions. Prevalence rates, correlation coefficients, standardised regression coefficients and odds ratios were calculated as measures of association. Concerning the main research question and relating to the entire study sample, WLI was found to be more strongly associated with general stress and burnout than ERI. As stratified analyses with regard to burnout have shown, this applied especially to nursing, technical care and emergency staffs who account for more than three fifths of the study population. But for other professional categories like physicians, therapists and medical-technical personnel the opposite of a stronger association of ERI with burnout was found. Results also suggested that general stress plays a (rather minor) mediating role in the relationships between ERI and burnout and particularly between WLI and burnout. For the prevention of chronic stress and burnout one should consider both high efforts put into work as well as all job demands that are competing and interfering with family responsibilities or other private activities should be considered.

  1. Marine Fish Hybridization

    KAUST Repository

    He, Song

    2017-04-01

    Natural hybridization is reproduction (without artificial influence) between two or more species/populations which are distinguishable from each other by heritable characters. Natural hybridizations among marine fishes were highly underappreciated due to limited research effort; it seems that this phenomenon occurs more often than is commonly recognized. As hybridization plays an important role in biodiversity processes in the marine environment, detecting hybridization events and investigating hybridization is important to understand and protect biodiversity. The first chapter sets the framework for this disseration study. The Cohesion Species Concept was selected as the working definition of a species for this study as it can handle marine fish hybridization events. The concept does not require restrictive species boundaries. A general history and background of natural hybridization in marine fishes is reviewed during in chapter as well. Four marine fish hybridization cases were examed and documented in Chapters 2 to 5. In each case study, at least one diagnostic nuclear marker, screened from among ~14 candidate markers, was found to discriminate the putative hybridizing parent species. To further investigate genetic evidence to support the hybrid status for each hybrid offspring in each case, haploweb analysis on diagnostic markers (nuclear and/or mitochondrial) and the DAPC/PCA analysis on microsatellite data were used. By combining the genetic evidences, morphological traits, and ecological observations together, the potential reasons that triggered each hybridization events and the potential genetic/ecology effects could be discussed. In the last chapter, sequences from 82 pairs of hybridizing parents species (for which COI barcoding sequences were available either on GenBank or in our lab) were collected. By comparing the COI fragment p-distance between each hybridizing parent species, some general questions about marine fish hybridization were discussed: Is

  2. ATTENUATION OF HEMODYNAMIC STRESS RESPONSE DURING EMERGENCE FROM GENERAL ANAESTHESIA: A PROSPECTIVE RANDOMIZED CONTROLLED STUDY COMPARING FENTANYL AND DEXMEDETOMIDINE

    Directory of Open Access Journals (Sweden)

    Liyakhath

    2014-11-01

    Full Text Available : BACKGROUND: Tracheal extubation and emergence is associated with significant haemodynamic alterations and is poorly tolerated by patients with co-morbid conditions. We compared the efficacy of fentanyl and dexmedetomidine in mitigating haemodynamic stress response and assessed extubation quality in study groups. MATERIALS AND METHODS: One fifty patients of either sex, ASA grade I & II normotensive patients, aged 18-55 years undergoing elective surgeries under general anaesthesia were randomized into 3 equal groups. Anaesthetic technique was standardized. 10 minutes prior to extubation, patients in Group N, F and D received intravenous bolus infusion of 0.9% normal Saline, Fentanyl 1μg /kg and Dexmedetomidine 1μg /kg respectively over 10 minutes period. Heart Rate (HR, Systolic BP (SBP, Diastolic BP (DBP and Mean Arterial Pressure (MAP were noted at extubation, 2, 4, 6, 8, 10 min and at regular interval thereafter for a period of two hours. Extubation quality was evaluated on 5-point extubation quality scale [ scale 1 = no coughing, 2 = smooth extubation, minimal coughing (1 or 2 times, 3 = moderate coughing (3 or 4 times, 4 = severe coughing (5-10 times and straining, 5 = poor extubation, very uncomfortable (laryngospasm and coughing >10 times]. Ramsay sedation score and Aldrete’s recovery score were recorded. Any adverse events, use of rescue drugs and postoperative analgesics were noted. RESULTS: All the measured haemodynamic parameters were significantly elevated at extubation and at various points of observation in normal saline group than fentanyl and dexmedetomidine group (p=0.000. Tachycardia response was seen in 84% patients in group N, compared to 36% and 8% in group F & D respectively (p=0.000. Statistically significant hypertensive response was noticed in 43(86% patients of group N, 9(18% of group F and 3(6% of group D (p=0.000. Duration of tachycardia and hypertensive response was significantly longer in control group. Three

  3. Hybrid trajectory spaces

    NARCIS (Netherlands)

    Collins, P.J.

    2005-01-01

    In this paper, we present a general framework for describing and studying hybrid systems. We represent the trajectories of the system as functions on a hybrid time domain, and the system itself by its trajectory space, which is the set of all possible trajectories. The trajectory space is given a na

  4. Big Five Personality Traits and the General Factor of Personality as Moderators of Stress and Coping Reactions Following an Emergency Alarm on a Swiss University Campus

    NARCIS (Netherlands)

    M.P. Hengartner (Michael P.); D. van der Linden (Dimitri); L. Bohleber (Laura); A. von Wyl (Agnes)

    2017-01-01

    textabstractWe conducted an online survey including 306 participants aged 18-64years to assess the general factor of personality (GFP) and Big Five personality traits in relation to individual stress and coping reactions following a shooting emergency alarm at a Swiss university campus. Although the

  5. From epidemiology to daily life: linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study.

    Directory of Open Access Journals (Sweden)

    Dina Collip

    Full Text Available Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an endophenotype for psychotic disorders. We examined, in a longitudinal framework, whether baseline momentary assessment markers of stress reactivity would predict persistence of subclinical psychotic experiences over time. In a general population sample of female twins (N = 566, the Experience Sampling Method (ESM; repetitive random sampling of momentary emotions, psychotic experiences and context was used to assess (emotional and psychotic daily life stress reactivity. Persistence of subclinical psychotic experiences was based on the Community Assessment of Psychic Experiences (CAPE, assessed three times over 14 months post-baseline. It was investigated whether baseline daily life emotional and psychotic stress reactivity predicted persistence of psychotic experiences over time. Higher levels of emotional stress reactivity (a decrease in positive and an increase in negative affect in response to stress, and increased psychotic reactivity to daily stress was found in individuals with persistent psychotic experiences over time compared to individuals with transient psychotic experiences. The results suggest that markers of daily life stress reactivity may predict "macro-level" persistence of normally transient expression of psychotic liability over time. Linking daily life markers of altered reactivity in terms of emotions and psychotic experiences to longitudinal persistence of psychotic experiences, associated with increased risk of transition to overt mental disorder, may contribute to earlier and more accurate diagnosis of risk.

  6. Effects of the acute exposition to glyphosate-based herbicide on oxidative stress parameters and antioxidant responses in a hybrid Amazon fish surubim (Pseudoplatystoma sp).

    Science.gov (United States)

    Sinhorin, Valéria Dornelles Gindri; Sinhorin, Adilson Paulo; Teixeira, Jhonnes Marcos dos Santos; Miléski, Kelly Márcia Lazarotto; Hansen, Paula Carine; Moreira, Paula Sueli Andrade; Kawashita, Nair Honda; Baviera, Amanda Martins; Loro, Vania Lúcia

    2014-08-01

    The aim of this study was to investigate the effects of acute glyphosate (active ingredient) exposure on the oxidative stress biomarkers and antioxidant defenses of a hybrid surubim (Pseudoplatystoma sp). The fish were exposed to different herbicide concentrations for 96 h. The thiobarbituric acid-reactive substances (TBARS), protein carbonyls and antioxidant responses were verified. The 15 mg a.pL(-1) of herbicide resulted in the death of 50% of the fish after 96 h. An increase in liver and muscle TBARS levels was observed when fish were exposed to the herbicide. The protein carbonyl content was also increased in the liver (4.5mg a.pL(-1) concentration) and brain (2.25 mg a.pL(-1) concentration). The antioxidant activities decreased in the liver and brain after exposure to herbicide. Levels of ascorbic acid in the liver (2.25 mg a.pL(-1) and 4.5 mg a.pL(-1) concentrations) and brain (2.25 mg a.pL(-1) concentration) were increased post-treatment. Levels of total thiols were increased in the liver and brain (2.25 mg L(-1) and 7.5mg a.pL(-1), respectively). Glyphosate exposure, at the tested concentrations affects surubim health by promoting changes that can affect their survival in natural environment. Some parameters as TBARS and protein carbonyl could be early biomarkers for Roundup exposure in this fish species.

  7. An Assessment Of Level Of Work-Related Stress Among Nursing Officers In Sri Jayewardenepura General Hospital In Sri Lanka

    Directory of Open Access Journals (Sweden)

    W.A.Nishshanka

    2015-08-01

    Full Text Available Abstract Stress is a state of emotional cognitive behavioral and physical reactions to unfavorable situations and is characterized by high levels of arousal distress and feelings of not coping. It has major behavioral and health implications. Stress has a special significance in health care where the workers experience both psychosocial and physical stress. As front-line health care workers who are in the wards for twenty four hours a day Nursing Officers are at high risk of stress due to their enormous responsibilities. In the ward setting they act as the link between the physicians patients and the community.

  8. Hybrid Neural Network Architecture for On-Line Learning

    CERN Document Server

    Chen, Yuhua; Wang, Lei

    2008-01-01

    Approaches to machine intelligence based on brain models have stressed the use of neural networks for generalization. Here we propose the use of a hybrid neural network architecture that uses two kind of neural networks simultaneously: (i) a surface learning agent that quickly adapt to new modes of operation; and, (ii) a deep learning agent that is very accurate within a specific regime of operation. The two networks of the hybrid architecture perform complementary functions that improve the overall performance. The performance of the hybrid architecture has been compared with that of back-propagation perceptrons and the CC and FC networks for chaotic time-series prediction, the CATS benchmark test, and smooth function approximation. It has been shown that the hybrid architecture provides a superior performance based on the RMS error criterion.

  9. 二倍体和四倍体杂交兰幼苗对低温胁迫的生理响应差异分析%Analysis on difference in physiological response of diploid and tetraploid of Cymbidium hybrid seedling to low temperature stress

    Institute of Scientific and Technical Information of China (English)

    王园园; 叶志琴; 刘容; 王广东

    2014-01-01

    . On this basis, difference in tolerance of diploid and tetraploid of Cymbidium hybrid to low temperature was compared. The results show that with prolonging of stress time, contents of proline, soluble sugar, soluble protein and MDA, O-·2 production rate and activities of POD and CAT in seedling leaf of diploid of Cymbidium hybrid and tetraploid strains T1 and T2 of Cymbidium hybrid totally appear gradually increasing trend, chlorophyll content appears gradually decreasing trend, and SOD activity appears the trend of firstly increasing and then decreasing and reaches the peak value on the 9th and 6th days of stress, respectively. On the 3rd day of recovery growth under normal temperature (25 ℃), contents of proline, soluble sugar, soluble protein and MDA, O-·2 production rate and activities of SOD, POD and CAT in seedling leaf of diploid of Cymbidium hybrid and tetraploid strains T1 and T2 of Cymbidium hybrid all decrease, while chlorophyll content increases. In general, in seedling leaf of diploid of Cymbidium hybrid, increasing ranges of contents of proline, soluble sugar and soluble protein and activities of SOD, POD and CAT are obviously lower and those of MDA content and O-·2 production rate are higher than those of tetraploid of Cymbidium hybrid, while decreasing range of chlorophyll content is obviously higher than that of tetraploid of Cymbidium hybrid. The comprehensive analysis result shows that both osmoregulation substance content and protective enzyme activity in leaf of tetraploid of Cymbidium hybrid are higher and its tolerance to low temperature is stronger than those of diploid of Cymbidium hybrid under low temperature stress.

  10. Internalizing Disorders and Leukocyte Telomere Erosion: A Prospective Study of Depression, Generalized Anxiety Disorder and Post-Traumatic Stress Disorder

    Science.gov (United States)

    Shalev, Idan; Moffitt, Terrie E.; Braithwaite, Antony W.; Danese, Andrea; Fleming, Nicholas I.; Goldman-Mellor, Sidra; Harrington, HonaLee; Houts, Renate M.; Israel, Salomon; Poulton, Richie; Robertson, Stephen P.; Sugden, Karen; Williams, Benjamin; Caspi, Avshalom

    2013-01-01

    There is evidence that persistent psychiatric disorders lead to age-related disease and premature mortality. Telomere length has emerged as a promising biomarker in studies that test the hypothesis that internalizing psychiatric disorders are associated with accumulating cellular damage. We tested the association between the persistence of internalizing disorders (depression, generalized anxiety disorder and post-traumatic stress disorder) and leukocyte telomere length (LTL) in the prospective-longitudinal Dunedin Study (N=1037). Analyses showed that the persistence of internalizing disorders across repeated assessments from ages 11 to 38 years predicted shorter LTL at age 38 years in a dose-response manner, specifically in men (β= −.137, 95% CI: −.232, −.042, p=.005). This association was not accounted for by alternative explanatory factors, including childhood maltreatment, tobacco smoking, substance dependence, psychiatric medication use, poor physical health, or low socioeconomic status. Additional analyses using DNA from blood collected at two time points (ages 26 and 38 years) showed that LTL erosion was accelerated among men who were diagnosed with internalizing disorder in the interim (β= −.111, 95% CI: −.184, −.037, p=.003). No significant associations were found among women in any analysis, highlighting potential sex differences in internalizing-related telomere biology. These findings point to a potential mechanism linking internalizing disorders to accelerated biological aging in the first half of the life course, particularly in men. Because internalizing disorders are treatable, the findings suggest the hypothesis that treating psychiatric disorders in the first half of the life course may reduce the population burden of age-related disease, and extend health expectancy. PMID:24419039

  11. for hybrid dynamical systems

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2001-01-01

    Full Text Available In this paper we develop a unified dynamical systems framework for a general class of systems possessing left-continuous flows; that is, left-continuous dynamical systems. These systems are shown to generalize virtually all existing notions of dynamical systems and include hybrid, impulsive, and switching dynamical systems as special cases. Furthermore, we generalize dissipativity, passivity, and nonexpansivity theory to left-continuous dynamical systems. Specifically, the classical concepts of system storage functions and supply rates are extended to left-continuous dynamical systems providing a generalized hybrid system energy interpretation in terms of stored energy, dissipated energy over the continuous-time dynamics, and dissipated energy over the resetting events. Finally, the generalized dissipativity notions are used to develop general stability criteria for feedback interconnections of left-continuous dynamical systems. These results generalize the positivity and small gain theorems to the case of left-continuous, hybrid, and impulsive dynamical systems.

  12. Global analysis of ocean surface wind and wind stress using a general circulation model and Seasat scatterometer winds

    Science.gov (United States)

    Kalnay, E.; Atlas, R.

    1986-01-01

    Instantaneous and 15-day time-averaged fields of surface wind, wind stress, curl of the wind stress, and wind divergence are presented. These fields are derived from the Goddard Laboratory for Atmospheres four-dimensional analysis/forecast cycle, for the period September 6-30, 1978, using conventional data, satellite temperature soundings, cloud-track winds, and subjectively dealiased Seasat scatterometer winds.

  13. Generalized product

    OpenAIRE

    Greco,Salvatore; Mesiar, Radko; Rindone, Fabio

    2014-01-01

    Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

  14. Generalized product

    OpenAIRE

    Greco, Salvatore; Mesiar, Radko; Rindone, Fabio

    2014-01-01

    Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

  15. 5-HTTLPR × interpersonal stress interaction and nonsuicidal self-injury in general community sample of youth.

    Science.gov (United States)

    Hankin, Benjamin L; Barrocas, Andrea L; Young, Jami F; Haberstick, Brett; Smolen, Andrew

    2015-02-28

    No research with youth has investigated whether measured genetic risk interacts with stressful environment (G⁎E) to explain engagement in non-suicidal self-injury (NSSI). Two independent samples of youth were used to test the a priori hypothesis that the Transporter-Linked Polymorphic Region (5-HTTLPR) would interact with chronic interpersonal stress to predict NSSI. We tested this hypothesis with children and adolescents from United States public schools in two independent samples (N׳s=300 and 271) using identical procedures and methods. They were interviewed in person with the Self-Injurious Thoughts and Behaviors Interview to assess NSSI engagement and with the UCLA Chronic Stress Interview to assess interpersonal stress. Buccal cells were collected for genotyping of 5-HTTLPR. For both samples, ANOVAs revealed the hypothesized G*E. Specifically, short carriers who experienced severe interpersonal stress exhibited the highest level of NSSI engagement. Replicated across two independent samples, results provide the first demonstration that youth at high genetic susceptibility (5-HTTLPR) and high environmental exposure (chronic interpersonal stress) are at heightened risk for NSSI. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. The Effectiveness of Group Training of CBT-Based Stress Management on Anxiety, Psychological Hardiness and General Self-Efficacy Among University Students.

    Science.gov (United States)

    Molla Jafar, Hamdam; Salabifard, Seddigheh; Mousavi, Seyedeh Maryam; Sobhani, Zahra

    2015-09-28

    Admission to university is a very sensitive period of life for efficient, active, and young workforces in any country, and it is mostly associated with many changes in social and human relationships. These changes lead to anxiety in students. Moreover, humans need certain functions in order to adaptively deal with different life situations and challenges. By training stress management, these functions can help human acquire the required abilities. The present study was aimed at investigating the effectiveness of stress management training in anxiety, psychological hardiness, and general self-efficacy among university students. The study was a quasi-experimental intervention (pretest-posttest-follow-up) including a control group, it was a fundamental applied study. The statistical population consisted of all students of Islamic Azad University, Karaj, Iran. Convenient sampling was employed to select 30 students who were divided into an experimental group (n=15) and a control group (n=15). Before stress management training, both groups filled out Beck Anxiety Inventory, Long and Goulet scale of psychological hardiness, and General Self-efficacy Scale (GSE-10). Afterwards, the experimental group was provided with stress management training. And after the experiment, the abovementioned questionnaires and scales were responded by the two groups. Finally the collected data were analyzed and compared using one-way MANOVA. The results of MANOVA indicated that there was a significant difference between the two groups in terms of anxiety, hardiness, and general self-efficacy (pstress management among university students cause anxiety to drop; moreover, it enhances their psychological hardiness and self-efficacy. In regard with the role and importance of stress management, training this skill should be included in educational plans of university.

  17. Excessive heart rate increase during mild mental stress in preparation for exercise predicts sudden death in the general population.

    Science.gov (United States)

    Jouven, Xavier; Schwartz, Peter J; Escolano, Sylvie; Straczek, Céline; Tafflet, Muriel; Desnos, Michel; Empana, Jean Philippe; Ducimetière, Pierre

    2009-07-01

    The aim of this study involves the early identification, among apparently healthy individuals, of those at high risk for sudden cardiac death. We tested the hypothesis that individuals who respond to mild mental stress in preparation for exercise test with the largest heart rate increases might be at highest risk. Data from 7746 civil servants participating in the Paris Prospective Study I, followed-up for 23 years, allowed to compare heart rate changes between rest and mild mental stress (preparation prior to an exercise test) between subjects who suffered sudden cardiac death (n = 81), non-sudden (n = 129) coronary death, or death from any cause (n = 1306). The mean heart rate increase during mild mental stress was 8.9 +/- 10.8 b.p.m. Risk of sudden cardiac death increased progressively with heart rate increase during mental stress and the relative risk of the third vs. the first tertile was 2.09 (95% confidence interval, 1.13-3.86) after adjustment for confounders. This relationship was not observed for non-sudden coronary death. An important heart rate increase produced by a mild mental stress predicts long-term risk for sudden cardiac death. Heart rate changes before an exercise test may provide a simple tool for risk stratification.

  18. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  19. Erianthus arundinaceus HSP70 (EaHSP70) Acts as a Key Regulator in the Formation of Anisotropic Interdigitation in Sugarcane (Saccharum spp. hybrid) in Response to Drought Stress.

    Science.gov (United States)

    Augustine, Sruthy Maria; Cherian, Anoop V; Syamaladevi, Divya P; Subramonian, N

    2015-12-01

    Plant growth during abiotic stress is a long sought-after trait especially in crop plants in the context of global warming and climate change. Previous studies on leaf epidermal cells have revealed that during normal growth and development, adjacent cells interdigitate anisotropically to form cell morphological patterns known as interlocking marginal lobes (IMLs), involving the cell wall-cell membrane-cortical actin continuum. IMLs are growth-associated cell morphological changes in which auxin-binding protein (ABP), Rho GTPases and actin are known to play important roles. In the present study, we investigated the formation of IMLs under drought stress and found that Erianthus arundinaceus, a drought-tolerant wild relative of sugarcane, develops such growth-related cell morphological patterns under drought stress. Using confocal microscopy, we showed an increasing trend in cortical F-actin intensity in drought-tolerant plants with increasing soil moisture stress. In order to check the role of drought tolerance-related genes in IML formation under soil moisture stress, we adopted a structural data mining strategy and identified indirect connections between the ABPs and heat shock proteins (HSPs). Initial experimental evidence for this connection comes from the high transcript levels of HSP70 observed in drought-stressed Erianthus, which developed anisotropic interdigitation, i.e. IMLs. Subsequently, by overexpressing the E. arundinaceus HSP70 gene (EaHSP70) in sugarcane (Saccharum spp. hybrid), we confirm the role of HSP70 in the formation of anisotropic interdigitation under drought stress. Taken together, our results suggest that EaHSP70 acts as a key regulator in the formation of anisotropic interdigitation in drought-tolerant plants (Erianthus and HSP70 transgenic sugarcane) under moisture stress in an actin-mediated pathway. The possible biological significance of the formation of drought-associated interlocking marginal lobes (DaIMLs) in sugarcane plants upon

  20. Interest of general tools of functional simulation in the idea of `mecatronic` groups: an application to energy management of hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Esteve, D.; Jammes, B.; Vinassa, J.M.; Marpinard, J.C.

    1994-04-01

    This report is a first approach of the simulation to validate the structure of the traction chain of a hybrid vehicle. This first step relies on the use of existing models in libraries of simulation programs. The next steps are going to consist in improving these models, in writing others one more performing and to test this simulation about energy management. (N.C.).

  1. Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress-tensors

    CERN Document Server

    Deffayet, C; Esposito-Farèse, G

    2009-01-01

    We extend to curved backgrounds all flat-space scalar field models that obey purely second-order equations, while maintaining their second-order dependence on both field and metric. This extension simultaneously restores to second order the, originally higher derivative, stress-tensors as well. The process is transparent and uniform for all dimensions.

  2. The general control nonderepressible-2 kinase mediates stress response and longevity induced by target of rapamycin inactivation in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Rousakis, Aris; Vlassis, Arsenios; Vlanti, Anna;

    2013-01-01

    -sensing pathway, the target of rapamycin (TOR). We also demonstrated that the GCN-2 and TOR signaling pathways converge on the PHA-4/FoxA transcription factor and its downstream target genes to ensure survival of the whole organism under a multitude of stress conditions, such as nutrient scarcity or environmental...

  3. Reflections on the Theories of Aging, of Oxidative Stress, and of Science in General. Is It Time to Abandon the Free Radical (Oxidative Stress) Theory of Aging?

    Science.gov (United States)

    Liochev, Stefan I

    2015-07-20

    Aging and oxidative stress are complex phenomena, and their understanding is of enormous theoretical and practical significance. Numerous hypotheses and theories that attempt to explain these phenomena have been developed. These hypotheses and theories compete with each other, with each claiming to be the correct one, while significantly contradicting each other. It is important to develop a maximally correct theory that may then trigger significant practical breakthroughs. None of these theories is entirely correct or close enough to the truth. However, most of them contain many correct elements (CE). Finding these CE is possible by analysis of these theories. Once the CE are found, they can be merged by synthesis in a better new theory. An analysis of some of the theories of aging followed by synthesis is attempted.

  4. 转AtDREB1A基因菊花杂交后代优株水分胁迫耐性分析%Drought Stress Tolerance of the Hybrid Offspring Produced by AtDREB1A Transgenic Chrysanthemum

    Institute of Scientific and Technical Information of China (English)

    杨英杰; 李春水; 张晓娇; 魏倩; 高俊平; 洪波

    2013-01-01

    过量表达拟南芥(A rab idopsis thaliana)逆境诱导转录因子DREB1A基因(AtDREB1A)能提高菊花的干旱胁迫耐性.以具有干旱胁迫耐性的转AtDREB1A基因菊花(Chrysanthemum morifolium)株系与广泛应用的非转基因菊花品种进行常规杂交获得的后代优株A-121、A-128、A-136为实验材料,进行了RT-PCR检测、水分胁迫下的萎蔫指数和成活率统计以及脯氨酸(Pro)含量和超氧化物歧化酶(SOD)活性测定.结果显示,外源A tDREB1A基因能够在有性繁殖过程中遗传给后代,且在水分胁迫下能在杂交后代植株中表达;与对照相比,水分胁迫条件下,转基因植株杂交后代Pro含量和SOD活性明显升高,且具有较强的水分胁迫耐性.研究结果表明,转基因菊花所携带的A tDREB1A基因可以在常规杂交中稳定遗传并发挥功能,提高了植株对水分胁迫的耐性.本研究为通过基因工程和传统育种结合方式选育具有干旱耐性的菊花新品种提供了技术平台.%Overexpression of the stress-inducible transcription factor gene A tDREB1A in Chrysanthemum conferred strong drought stress tolerance. Taking A-112, A-128 and A-136 as experimental materials, which are the three excellent hybrid offspring plants of the ground cover Chrysanthemum fall color transgenic line 1805 with drought stress tolerance harboring Arabidopsis thaliana dehydration response element-binding protein 1A (AtDREB1A) and the Asia Winter Light with better phenotype, we analyzed the stability and expression of AtDREB1A under water stress condition by RT-PCR, and determined the wilting index, survival rate, proline(Pro) content and superoxide dismutase(SOD) activity under drought stress condition. The results demonstrated that the exogenous gene AtDREB1A A was transferred into the hybrid offspring plants by sexual propagation and it could be expressed in offspring plants under drought condition. Compared with the control plants, the hybrid offspring plants

  5. Stability Parameters for Grain Yield and its Component Traits in Maize Hybrids of Different FAO Maturity Groups

    Directory of Open Access Journals (Sweden)

    Dragan Djurovic

    2014-12-01

    Full Text Available An objective evaluation of maize hybrids in intensive cropping systems requires identification not only of yield components and other agronomically important traits but also of stability parameters. Grain yield and its components were assessed in 11 maize hybrids with different lengths of growing season (FAO 300-700 maturity groups using analysis of variance and regression analysis at three different locations in Western Serbia. The test hybrids and locations showed significant differences in grain yield, grain moisture content at maturity, 1,000-kernel weight and ear length. A significant interaction was observed between all traits and the environment. The hybrids with higher mean values of the traits, regardless of maturity group, generally exhibited sensitivity i.e. adaptation to more favourable environmental conditions as compared to those having lower mean values. Regression coefficient (bi values for grain yield mostly suggested no significant differences relative to the mean. The medium-season hybrid gave high yields and less favourable values of stability parameters at most locations and in most years, as compared to mediumlate hybrids. As compared to medium-early hybrids, medium-late hybrids (FAO 600 and 700 mostly exhibited unfavourable values of stability parameters i.e. a specific response and better adaptation to favourable environmental conditions, and gave higher average yields. Apart from producing lower average yields, FAO 300 and 400 hybrids showed higher yield stability as compared to the other hybrids tested. Medium-late hybrids had higher yields and showed a better response to favourable environmental conditions compared to early-maturing hybrids. Therefore, they can be recommended for intensive cultural practices and low-stress environments. Due to their more favourable stability parameter values, medium-early hybrids can be recommended for low-intensity cultural practices and stressful environments.

  6. A Cross-sectional Study on Posttraumatic Stress Disorder and General Psychiatric Morbidity Among Adult Survivors 3 Years After the Wenchuan Earthquake, China.

    Science.gov (United States)

    Zhang, Wei; Duan, Guangfeng; Xu, Qin; Jia, Zhaobao; Bai, Zhengyang; Liu, Weizhi; Pan, Xiao; Tian, Wenhua

    2015-11-01

    After the Wenchuan earthquake, a large number of studies have focused on postearthquake psychological disorders among survivors; however, most of these studies were conducted within a relatively short period. This study was conducted to examine the symptoms of posttraumatic stress disorder (PTSD) and general psychiatric morbidity among adult survivors 3 years after the Wenchuan earthquake, China. Through a multistage systematic sampling approach, a cross-sectional survey of 360 participants, 18 years or older, was conducted. The prevalence of PTSD and general psychiatric morbidity was 10.3% and 20.6%, respectively. Multivariate analysis revealed significant predictors for PTSD, including female gender and having felt guilt concerning someone's death or injury. Significant predictors for general psychiatric morbidity included unmarried status and having been in serious danger. These results suggest that mental health services should be continuously available to earthquake survivors.

  7. RELAÇÕES HÍDRICAS EM DOIS HÍBRIDOS DE MILHO SOB DOIS CICLOS DE DEFICIÊNCIA HÍDRICA WATER RELATIONS IN TWO HYBRIDS OF CORN UNDER TWO CYCLES OF WATER STRESS

    Directory of Open Access Journals (Sweden)

    CARLOS PIMENTEL

    1999-11-01

    Full Text Available Neste trabalho foram estudadas as relações hídricas de dois híbridos de milho (Zea mays L., em casa de vegetação: o IAC 8222 (híbrido com tolerância ambiental e o DINA 10 (híbrido comum; submetidos a um ou a dois ciclos de estresse, aos 30 e 46 DAP. O IAC 8222 manteve o potencial hídrico de folha (psihf superior ao do DINA no primeiro ciclo de estresse e no segundo ciclo, em plantas que sofreram os dois ciclos (com endurecimento, no sexto e último dia de deficiência hídrica, não havendo diferenças em relação ao conteúdo hídrico relativo (CHR entre os híbridos. Houve um aumento da concentração de açúcares solúveis e de aminoácidos com a deficiência hídrica, sem diferenças entre os híbridos no primeiro ciclo de déficit hídrico, e com aumento significativo somente na concentração de aminoácidos no DINA 10 submetido aos dois ciclos, no último dia do segundo ciclo. A concentração de K+ não variou nem com os ciclos nem entre híbridos. Portanto, só houve diferenças na acumulação de solutos osmóticos entre os híbridos, quanto ao teor de aminoácidos no DINA 10 submetido aos dois ciclos, no segundo ciclo. Contudo, o IAC 8222 manteve o seu psihf alto, podendo ter promovido um ajuste do coeficiente de extensibilidade de parede, que foi acentuado com o endurecimento.A study was conducted to evaluate the water relations of two corn (Zea mays L. hybrids in a greenhouse experiment: IAC 8222 (hybrid adapted to environmental stress and DINA 10 (common hybrid, under one or two cycles of water stress applied at 30 and 46 days after sowing. During the first water deficit cycle, and at the second cycle for plants submitted to both cycles, the leaf water potential (psihf of IAC 8222 was higher than the psihf of DINA 10, at the 6th and last day of water stress, with no difference for the relative water content (CHR between the hybrids. The soluble sugars and amino acids accumulated during the water stress, but no

  8. A two-component system, an anti-sigma factor and two paralogous ECF sigma factors are involved in the control of general stress response in Caulobacter crescentus.

    Science.gov (United States)

    Lourenço, Rogério F; Kohler, Christian; Gomes, Suely L

    2011-06-01

    The extracytoplasmic function sigma factor σ(T) is the master regulator of general stress response in Caulobacter crescentus and controls the expression of its paralogue σ(U). In this work we showed that PhyR and NepR act, respectively, as positive and negative regulators of σ(T) expression and function. Biochemical data also demonstrated that NepR directly binds σ(T) and the phosphorylated form of PhyR. We also described the essential role of the histidine kinase gene CC3474, here denominated phyK, for expression of σ(T)-dependent genes and for resistance to stress conditions. Additionally, in vivo evidence of PhyK-dependent phosphorylation of PhyR is presented. This study also identified a conserved cysteine residue (C95) located in the periplasmic portion of PhyK that is crucial for the function of the protein. Furthermore, we showed that PhyK, PhyR and σ(T) regulate the same set of genes and that σ(T) apparently directly controls most of its regulon. In contrast, σ(U) seems to have a very modest contribution to the expression of a subset of σ(T)-dependent genes. In conclusion, this report describes the molecular mechanism involved in the control of general stress response in C. crescentus.

  9. Efficacy of an Extract of Ocimum tenuiflorum (OciBest in the Management of General Stress: A Double-Blind, Placebo-Controlled Study

    Directory of Open Access Journals (Sweden)

    Ram Chandra Saxena

    2012-01-01

    Full Text Available A randomized, double-blind, placebo-controlled study was conducted to evaluate the efficacy of OciBest, an extract of Ocimum tenuiflorum Linn. in symptomatic control of general stress. The participants received either placebo (n=79 or OciBest (n=71; 1200 mg of actives per day for six weeks. The severity of stress-related symptoms was self-evaluated by patients at weeks 0, 2, 4 and 6 of the trial period using a symptom rating scale. After six weeks of intervention, scores of symptoms such as forgetfulness, sexual problems of recent origin, frequent feeling of exhaustion, and frequent sleep problems of recent origin decreased significantly (P≤0.05 in OciBest group as compared with placebo group. Also, the total symptom scores of OciBest group revealed significant reduction (P≤0.05 as compared to placebo group. The overall improvement in OciBest group was found to be 1.6 times or 39% more in the control of general stress symptoms with respect to placebo. No adverse events were reported during the study. The findings revealed that OciBest was found to be effective and well tolerated by all the patients over the six weeks of study period.

  10. The Efficacy of the Training of Stress Management by Cognitive-Behavior Method on Addicts’ Anxiety of with Generalized Anxiety Disorder

    Directory of Open Access Journals (Sweden)

    Zahra Lak

    2013-01-01

    Full Text Available Aim: The purpose of this study was to investigate the effectiveness of cognitive–behavioral stress management on reduction of anxiety among addicts with GAD. Method: The design of the study is experimental with pretest -posttest and control group. The population of the study was all addicts with GAD in Tehran self-referred centers that scored the most points in GAD-7 test. 24 addicts were allocated into experimental group (N=12 and control group (N=12. The cognitive-behavioral stress management was demonstrated in 10 weekly sessions on the experimental group while there was no psychological treatment for the control group. DASS-21 questionnaire and GAD-7 questionnaire were completed by both groups before and after program. The data was analyzed using covariance. Results: There were no significant differences in anxiety between two groups before intervention. Results of this study demonstrated that cognitive –behavioral stress management led to significant decrease in anxiety in experimental group. Conclusion: Regarding to effectiveness of cognitive-behavioral stress management on anxiety, it may also be used as a supplement method decreasing generalized anxiety disorder among addicts.

  11. Big Five Personality Traits and the General Factor of Personality as Moderators of Stress and Coping Reactions Following an Emergency Alarm on a Swiss University Campus.

    Science.gov (United States)

    Hengartner, Michael P; van der Linden, Dimitri; Bohleber, Laura; von Wyl, Agnes

    2017-02-01

    We conducted an online survey including 306 participants aged 18-64 years to assess the general factor of personality (GFP) and Big Five personality traits in relation to individual stress and coping reactions following a shooting emergency alarm at a Swiss university campus. Although the emergency eventually turned out to be a false alarm, various witnesses showed pronounced distress owing to a vast police operation. The GFP structure was replicated using two alternative modelling approaches. Neuroticism related substantially to acute fear and traumatic distress as well as to more enduring maladaptive coping. Agreeableness was negatively associated with the coping strategy of medication use, whereas both agreeableness and conscientiousness related positively to social activity following the emergency. The GFP related moderately to peri-traumatic distress and showed a substantial negative association with medication use and a strong positive association with social activity. In conclusion, both the GFP and Big Five traits significantly moderate stress responses following a stressful life event. The GFP predominantly relates to socially adaptive coping, whereas in particular neuroticism accounts for acute stress reactions such as fear and traumatic distress. These findings support the notion that personality influences how persons react in the face of adversity. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. General unknown screening in hair by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS).

    Science.gov (United States)

    Broecker, Sebastian; Herre, Sieglinde; Pragst, Fritz

    2012-05-10

    The retrospective investigation of the exposure to toxic substances by general unknown screening of hair is still a difficult task because of the large number of possible poisons, the low sample amount and the difficult sample matrix. In this study the use of liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was tested as a promising technique for this purpose. In the optimized procedure, 20mg hair were decontaminated with water and acetone and two times extracted by 18h incubation with 0.5ml of a mixture of methanol/acetonitrile/H(2)O/ammonium formate at 37°C. A mixture of deuterated standards from different drug groups was added for quantification and method control. The united extracts were evaporated to a residue of 0.5ml and 5μl were injected without clean-up for LC-QTOF-MS measurement (instrument Agilent 6530) with positive electrospray ionization and in data dependent acquisition mode. For peak identification the accurate mass data base and spectral library of the authors was used which contains accurate mass CID spectra of more than 2500 and theoretically calculated accurate mass data of more than 7500 toxicologically relevant substances. Validation at the example of 24 illegal drugs, their metabolites and benzodiazepines resulted in limits of detection of 0.003-0.015ng/mg, and limits of quantification of 0.006-0.021ng/mg with good accuracy and intra- and interday reproducibility. The matrix effect by ion suppression/enhancement was 72-107% for basic drugs and 42-75% for benzodiazepines. Yields of the hair extraction above 90% were determined for 59 drugs or metabolites. The method was applied to hair samples from 30 drug fatalities and from 60 death cases with known therapeutic drug intake at life time. Altogether 212 substances were identified with a frequency per drug of 1-40 (mean 4.2) and per case of 2-33 (mean 10.2), between them 35 illegal drug related substances and 154 therapeutic drugs. Comparison with the

  13. 三系杂交棉花粉育性对高温和低温胁迫的反应%Reaction of Pollen Fertility to High or Low Temperature Stresses in CMS-Based Hybrid Cotton

    Institute of Scientific and Technical Information of China (English)

    倪密; 王学德; 张昭伟; 朱云国; 张海平; 邵明彦; 袁淑娜; 刘英新; 文国吉

    2009-01-01

    Planting CMS-based hybrid cotton is an important way to use cotton hetcrosis. Fertility of hybrid cotton pollens is in-fluenced by cultivar, climatic conditions, management practices and pests. Among all the factors, temperature is the primary one affecting cotton growth, the following is air humidity. Stability of pollen fertility under high and low temperature stresses, associ-ated with the hetcrosis expression of CMS-based hybrids, is the main point to elucidate in this study. The fertility differences be-tween hybrids and the maintainer were compared by testing the percentage of fertile pollens in the greenhouse experiment with temperature controlled and the field experiment with natural temperature. In addition, percentage of setting bolls and percentage of aborted seeds were tested in the field experiment. Pollen fertility was checked by benzidine-Naphthol fluorescence microscopic method, while cross-pollination experiments were performed by dusting pollen obtained from corresponding restorers, then per-centage of setting boils and percentage of aborted seeds were determined by calculating the number of boils or seeds, respectively. The critical temperatures for upper limit and lower limit were searched from different given consistent temperatures, which each temperature was kept for eight days in the greenhouse when cotton pollens turned from fertility to sterility. The results showed that the response of CMS-based hybrids to the extreme temperature stress was more sensitive than that of the maintainer, while the former usually had lower stability in pollen vitality under the stress. However, different CMS-based hybrids had various toler-ances to temperature stress, for example, hybrids (F_1) restored by Zheda strong restorer showed higher pollen viability, more set-ting bolls and less aborted seeds under the stress than others. The response of pollen fertility to air temperature had a 5-day's delay in the field. Furthermore, the changes of maximum air

  14. Dispersion Relation Tool for generalized lower-hybrid mode with, density gradient, equilibrium ExB drift, collisions and finite electron Larmor radius

    CERN Document Server

    Romadanov, Ivan; Frias, Winston; Chapurin, Oleksandr; Koshkarov, Oleksandr

    2016-01-01

    MATLAB solver has been developed for studies of local instabilities in partially magnetized plasmas typical for ExB discharge plasmas. Examples for the Simon-Hoh, lower-hybrid and ion-sound instabilities in Penning discharge. The detailed behavior of the local dispersion relation can be investigated, plotted and saved with this solver. It allows to include various effects, change plasma parameters and obtain eigen-frequencies as a function of the wavenumbers in x or y directions.

  15. Contribution of interspecific hybridization to sunflower breeding

    OpenAIRE

    Christov M.

    2012-01-01

    This investigation is directed at improving sunflower using hybrid forms resulted from interspecific hybridization. The aim is to create new B/A and R lines from interspecific hybrid forms that are resistant to diseases, the parasite broomrape, herbicides, and other stress factors and are characterized with high combining ability and to obtain on this basis highly productive oilseed sunflower hybrids with varied fatty acid composition of oil. The investigat...

  16. A putative bifunctional histidine kinase/phosphatase of the HWE family exerts positive and negative control on the Sinorhizobium meliloti general stress response.

    Science.gov (United States)

    Sauviac, Laurent; Bruand, Claude

    2014-07-01

    The EcfG-type sigma factor RpoE2 is the regulator of the general stress response in Sinorhizobium meliloti. RpoE2 activity is negatively regulated by two NepR-type anti-sigma factors (RsiA1/A2), themselves under the control of two anti-anti-sigma factors (RsiB1/B2) belonging to the PhyR family of response regulators. The current model of RpoE2 activation suggests that in response to stress, RsiB1/B2 are activated by phosphorylation of an aspartate residue in their receiver domain. Once activated, RsiB1/B2 become able to interact with the anti-sigma factors and release RpoE2, which can then associate with the RNA polymerase to transcribe its target genes. The purpose of this work was to identify and characterize proteins involved in controlling the phosphorylation status of RsiB1/B2. Using in vivo approaches, we show that the putative histidine kinase encoded by the rsiC gene (SMc01507), located downstream from rpoE2, is able to both positively and negatively regulate the general stress response. In addition, our data suggest that the negative action of RsiC results from inhibition of RsiB1/B2 phosphorylation. From these observations, we propose that RsiC is a bifunctional histidine kinase/phosphatase responsible for RsiB1/B2 phosphorylation or dephosphorylation in the presence or absence of stress, respectively. Two proteins were previously proposed to control PhyR phosphorylation in Caulobacter crescentus and Sphingomonas sp. strain FR1. However, these proteins contain a Pfam:HisKA_2 domain of dimerization and histidine phosphotransfer, whereas S. meliloti RsiC harbors a Pfam:HWE_HK domain instead. Therefore, this is the first report of an HWE_HK-containing protein controlling the general stress response in Alphaproteobacteria.

  17. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  18. Worries are the mother of many diseases: General practitioners and refugees in the Netherlands on stress, being ill and prejudice

    NARCIS (Netherlands)

    Titia Feldmann, C.; Bensing, J.; Ruijter, Arie de

    Objective: To confront the views of refugee patients and general practitioners in the Netherlands, focusing on medically unexplained physical symptoms (MUPS). Methods: The study is based on in depth interviews with refugees from Afghanistan (n = 36) and Somalia (n = 30). Additionally,

  19. Sexual orientation and health : general and minority stress factors explaining health differences between lesbian, gay, bisexual and heterosexual individuals

    NARCIS (Netherlands)

    Kuyper, L.S.

    2011-01-01

    Previous studies show that lesbian, gay and bisexual (LGB) individuals report more health problems than heterosexual individuals. However, several important gaps remain in the knowledge regarding the explanations for these health differences. In general, there is a lack of differentiation between

  20. Sexual orientation and health : general and minority stress factors explaining health differences between lesbian, gay, bisexual and heterosexual individuals

    NARCIS (Netherlands)

    Kuyper, L.S.

    2011-01-01

    Previous studies show that lesbian, gay and bisexual (LGB) individuals report more health problems than heterosexual individuals. However, several important gaps remain in the knowledge regarding the explanations for these health differences. In general, there is a lack of differentiation between su

  1. Worries are the mother of many diseases: General practitioners and refugees in the Netherlands on stress, being ill and prejudice

    NARCIS (Netherlands)

    Titia Feldmann, C.; Bensing, J.; Ruijter, Arie de

    2007-01-01

    Objective: To confront the views of refugee patients and general practitioners in the Netherlands, focusing on medically unexplained physical symptoms (MUPS). Methods: The study is based on in depth interviews with refugees from Afghanistan (n = 36) and Somalia (n = 30). Additionally, semistructured

  2. Worries are the mothers of many diseases: general practitioners and refugees in the Netherlands on stress, being ill and prejudice.

    NARCIS (Netherlands)

    Feldmann, C.T.; Bensing, J.M.; Ruijter, A. de

    2007-01-01

    Objective: To confront the views of refugee patients and general practitioners in the Netherlands, focusing on medically unexplained physical symptoms (MUPS). Methods: The study is based on in depth interviews with refugees from Afghanistan (n=36) and Somalia (n=30). Additionally, semi-structured in

  3. THE EFFICACY OF PREGABALIN AS A PREMEDICANT IN ATTENUATING NEUROENDOCRINE STRESS RESPONSE DURING GENERAL ANAESTHESIA IN ELECTIVE SURGERIES: A PROSPECTIVE RANDOMISED PLACEBO CONTROLLED STUDY

    Directory of Open Access Journals (Sweden)

    Bhavani Muthukrishnan

    2016-06-01

    Full Text Available BACKGROUND The stress response to surgery is characterised by increased secretion of pituitary hormones and activation of the sympathetic nervous system. The changes triggered by the stress response are short-lived and well tolerated by normal healthy patients belonging to ASA 1 and 2. In patients with other comorbidities like myocardial ischaemia, renal insufficiency, uncontrolled diabetes, liver disease and cerebrovascular diseases, these changes can be life threatening. The recognition of the factors which initiate the stress response can be considered for modification in the preoperative period itself. Various anaesthetic techniques and pain management strategies have been put into use to control the stress response. AIM To study the rise in serum cortisol levels during surgery after administering oral pregabalin as a premedicant. SETTINGS AND DESIGN A Prospective Randomised Placebo Controlled Study. MATERIALS AND METHODS All consented patients were aged between 18 and 50 years belonging to ASA 1 & 2 undergoing elective surgical procedures under general anaesthesia of duration between 30 minutes and 180 minutes. Group A received oral placebo, Group B oral pregabalin 150 mg 60-90 minutes before surgery with sips of water. They were randomly allocated to a particular group using computer generated numbers. The ward staff nurse administered the drug kept in sealed envelopes. Both the patients and the person administering anaesthesia were unaware of the group. STATISTICAL ANALYSIS The results were analysed using SPSS Version 17 software with the help of the statistician. The students’ paired t-test was used to compare the mean change in the cortisol levels in the two groups. RESULTS There was a significant [p < 0.01] reduction in the intraoperative cortisol levels after premedication with pregabalin. There was an increase in serum cortisol levels after extubation in both the groups which was statistically significant (p < 0.01. CONCLUSION

  4. From hybrid swarms to swarms of hybrids

    Science.gov (United States)

    Stohlgren, Thomas J.; Szalanski, Allen L; Gaskin, John F.; Young, Nicholas E.; West, Amanda; Jarnevich, Catherine S.; Tripodi, Amber

    2015-01-01

    Science has shown that the introgression or hybridization of modern humans (Homo sapiens) with Neanderthals up to 40,000 YBP may have led to the swarm of modern humans on earth. However, there is little doubt that modern trade and transportation in support of the humans has continued to introduce additional species, genotypes, and hybrids to every country on the globe. We assessed the utility of species distributions modeling of genotypes to assess the risk of current and future invaders. We evaluated 93 locations of the genus Tamarix for which genetic data were available. Maxent models of habitat suitability showed that the hybrid, T. ramosissima x T. chinensis, was slightly greater than the parent taxa (AUCs > 0.83). General linear models of Africanized honey bees, a hybrid cross of Tanzanian Apis mellifera scutellata and a variety of European honey bee including A. m. ligustica, showed that the Africanized bees (AUC = 0.81) may be displacing European honey bees (AUC > 0.76) over large areas of the southwestern U.S. More important, Maxent modeling of sub-populations (A1 and A26 mitotypes based on mDNA) could be accurately modeled (AUC > 0.9), and they responded differently to environmental drivers. This suggests that rapid evolutionary change may be underway in the Africanized bees, allowing the bees to spread into new areas and extending their total range. Protecting native species and ecosystems may benefit from risk maps of harmful invasive species, hybrids, and genotypes.

  5. Studies on the relationship between the changes of the endogenous scavengers of active oxygen and resistance in hybrid rice under temperature stress

    Institute of Scientific and Technical Information of China (English)

    FANShuyang; GUOShaochuan

    1994-01-01

    The seedlings of indica hybrid rice Weiyou 49 and Weiyou 28 were exposed to 1℃ and 40℃ .and the changes of activity (content) of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbic acid (ASA), glutathione (GSH),malondialdehyde (MDA) and leakage of electrolytes (%) were measured.

  6. Ants exhibit asymmetric hybridization in a mosaic hybrid zone.

    Science.gov (United States)

    Purcell, Jessica; Zahnd, Sacha; Athanasiades, Anouk; Türler, Rebecca; Chapuisat, Michel; Brelsford, Alan

    2016-10-01

    Research on hybridization between species provides unparalleled insights into the pre- and postzygotic isolating mechanisms that drive speciation. In social organisms, colony-level incompatibilities may provide additional reproductive barriers not present in solitary species, and hybrid zones offer an opportunity to identify these barriers. Here, we use genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone between two socially polymorphic ant species, Formica selysi and Formica cinerea. We characterize the zone, determine the frequency of hybrid workers, infer whether hybrid queens or males are produced and investigate whether hybridization is influenced by colony social organization. We also compare cuticular hydrocarbon profiles and aggression levels between the two species. The hybrid zone exhibits a mosaic structure. The asymmetric distribution of hybrids skewed towards F. cinerea suggests a pattern of unidirectional nuclear gene flow from F. selysi into F. cinerea. The occurrence of backcrossed individuals indicates that hybrid queens and/or males are fertile, and the presence of the F. cinerea mitochondrial haplotype in 97% of hybrids shows that successful F1 hybrids will generally have F. cinerea mothers and F. selysi fathers. We found no evidence that social organization contributes to speciation, because hybrids occur in both single-queen and multiple-queen colonies. Strongly differentiated cuticular hydrocarbon profiles and heightened interspecific aggression further reveal that species recognition cues are both present and perceived. The discovery of fertile hybrids and asymmetrical gene flow is unusual in ants, and this hybrid zone will therefore provide an ideal system with which to investigate speciation in social insects.

  7. Effectiveness of a Minimal Intervention for Stress-related mental disorders with Sick leave (MISS; study protocol of a cluster randomised controlled trial in general practice [ISRCTN43779641

    Directory of Open Access Journals (Sweden)

    van Marwijk Harm WJ

    2006-05-01

    Full Text Available Abstract Background The main aims of this paper are to describe the setting and design of a Minimal Intervention in general practice for Stress-related mental disorders in patients on Sick leave (MISS, as well as to ascertain the study complies with the requirements for a cluster randomised controlled trial (RCT. The potential adverse consequences of sick leave due to Stress-related Mental Disorders (SMDs are extensive, but often not recognised. Since most people having SMDs with sick leave consult their general practitioner (GP at an early stage, a tailored intervention given by GPs is justified. We provide a detailed description of the MISS; that is more accurate assessment, education, advice and monitoring to treat SMDs in patients on sick leave. Our hypothesis is that the MISS will be more effective compared to the usual care, in reducing days of sick leave of these patients. Methods The design is a pragmatic RCT. Randomisation is at the level of GPs. They received the MISS-training versus no training, in order to compare the MISS vs. usual care at patient level. Enrolment of patients took place after screening in the source population, that comprised 20–60 year old primary care attendees. Inclusion criteria were: moderately elevated distress levels, having a paid job and sick leave for no longer than three months. There is a one year follow up. The primary outcome measure is lasting full return to work. Reduction of SMD- symptoms is one of the secondary outcome measures. Forty-six GPs and 433 patients agreed to participate. Discussion In our study design, attention is given to the practical application of the requirements for a pragmatic trial. The results of this cluster RCT will add to the evidence about treatment options in general practice for SMDs in patients on sick leave, and might contribute to a new and appropriate guideline. These results will be available at the end of 2006.

  8. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Rönnkö, M.; Ravn, Anders Peter; Sere, K.

    2003-01-01

    In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time-derivatives in modell......In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time...... parallel composition. Moreover, as the strength of the action system formalism is the support for stepwise development by refinement, we investigate refinement involving a differential action. We show that, due to the predicate transformer semantics, standard action refinement techniques apply also...... to the differential action, thus, allowing stepwise development of hybrid systems Udgivelsesdato: JAN 1...

  9. Conditional Hybrid Nonclassicality

    Science.gov (United States)

    Agudelo, E.; Sperling, J.; Costanzo, L. S.; Bellini, M.; Zavatta, A.; Vogel, W.

    2017-09-01

    We derive and implement a general method to characterize the nonclassicality in compound discrete- and continuous-variable systems. For this purpose, we introduce the operational notion of conditional hybrid nonclassicality which relates to the ability to produce a nonclassical continuous-variable state by projecting onto a general superposition of discrete-variable subsystem. We discuss the importance of this form of quantumness in connection with interfaces for quantum communication. To verify the conditional hybrid nonclassicality, a matrix version of a nonclassicality quasiprobability is derived and its sampling approach is formulated. We experimentally generate an entangled, hybrid Schrödinger cat state, using a coherent photon-addition process acting on two temporal modes, and we directly sample its nonclassicality quasiprobability matrix. The introduced conditional quantum effects are certified with high statistical significance.

  10. Contribution of interspecific and intergeneric hybridization to sunflower breeding

    OpenAIRE

    Christov M.

    2013-01-01

    This investigation was directed to sunflower improvement using hybrid forms resulted from wide hybridization. The aim was to create new B/A and R lines from interspecific and intergeneric hybrids resistant to diseases, parasite broomrape, herbicides, other stress factors and with high combining ability in highly productive oil-type sunflower hybrids with varied fatty acid contents. The confectionary hybrids should have a high kernel protein content and amin...

  11. First-Order Hybrid Logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Hybrid logic is an extension of modal logic which allows us to refer explicitly to points of the model in the syntax of formulas. It is easy to justify interest in hybrid logic on applied grounds, with the usefulness of the additional expressive power. For example, when reasoning about time one...... often wants to build up a series of assertions about what happens at a particular instant, and standard modal formalisms do not allow this. What is less obvious is that the route hybrid logic takes to overcome this problem often actually improves the behaviour of the underlying modal formalism....... For example, it becomes far simpler to formulate proof-systems for hybrid logic, and completeness results can be proved of a generality that is simply not available in modal logic. That is, hybridization is a systematic way of remedying a number of known deficiencies of modal logic. First-order hybrid logic...

  12. Dynamical systems revisited : Hybrid systems with Zeno executions

    OpenAIRE

    ZHANG, JUN; Johansson, Karl Henrik; Lygeros, John; Sastry, Shankar

    2000-01-01

    Results from classical dynamical systems are generalized to hybrid dynamical systems. The concept of omega limit set is introduced for hybrid systems and is used to prove new results on invariant sets and stability, where Zeno and non-Zeno hybrid systems can be treated within the same framework. As an example, LaSalle's Invariance Principle is extended to hybrid systems. Zeno hybrid systems are discussed in detail. The omega limit set of a Zeno execution is characterized for classes of hybrid...

  13. Comparative evaluation of oral clonidine and midazolam as premedication on preoperative sedation and laryngoscopic stress response attenuation for the patients undergoing general anaesthesia

    Directory of Open Access Journals (Sweden)

    Anjan Das

    2013-07-01

    Full Text Available Context: Laryngoscopy and endotracheal intubation is associated detrimental hemodynamic changes like rise in blood pressure (BP, heart rate (HR leading to adverse cardiological outcome specially in susceptible individuals. Aims: To compare the blood pressure (BP and heart rate (HR changes during laryngoscopy and endotracheal intubation as well as to evaluate the preoperative sedation status between oral clonidine and oral midazolam as premedication for the patients undergoing general anesthesia (GA. Settings and Design: Fifty patients between 18 and 60 years of age of either sex of American Society of Anesthesiologists (ASA Grade I and II undergoing GA were randomly divided into two equal groups of 25 patients each. Group-C patients received clonidine 4 mcg/kg orally and Group-M patients received 0.5 mg/kg midazolam orally as premedication. Material s and Methods: After measuring baseline hemodynamic parameters patients of both groups received premedication. Preoperative sedation was assessed 2 hr after premedication administration. Standard anesthetic technique was followed. Hemodynamic (HR, BP parameters were noted baseline, immediately after laryngoscopy and intubation and 5 min after intubation to observe the stress response. Results and Statistical Analysis: A significant difference in pre-operative sedation between two groups (P < 0.05 and midazolam (group M produced significantly better sedation than clonidine (group C. Laryngoscopic stress response in group C was still at a lower level than baseline values and significantly (P < 0.005 less than group M. Conclusions: Oral midazolam is more effective in producing preoperative sedation than oral clonidine while on the contrary oral clonidine is more efficacious in reducing laryngoscopic stress response than oral midazolam. Laryngoscopy and intubation was better controlled by oral clonidine than midazolam.

  14. Depression, Somatization, and Posttraumatic Stress Disorder in Children Born of Occupation After World War II in Comparison With a General Population.

    Science.gov (United States)

    Kaiser, Marie; Kuwert, Philipp; Braehler, Elmar; Glaesmer, Heide

    2015-10-01

    At the end of World War II and during the first decade after the war, roughly 200,000 children were fathered in intimate contacts between German women and foreign soldiers. The experiences of these German occupation children (GOC) have been so far described in case reports and from historical perspective only. Research on psychosocial consequences of growing up as a GOC has been missing so far. This study examined traumatic experiences, posttraumatic stress disorder, somatization, and depression in GOC (N = 146) using self-report instruments: Posttraumatic Diagnostic Scale and Patient Health Questionnaire. Findings have then been compared with a representative birth cohort-matched sample from the German general population (N = 977). German occupation children showed significantly higher prevalence rates of most traumatic experiences, higher point prevalence rates of full and partial posttraumatic stress disorder, depression, and somatization than the control group. In summary, GOC often grew up under difficult conditions (e.g., poverty, single mothers, and stigmatization). Even decades later, they showed higher rates of different mental disorders and higher comorbidity. These findings underline the complex and long-term impact of their burdened social, financial, and familial conditions. The results underpin the importance of conceptualizing occupation children as a vulnerable group in postconflict settings.

  15. The Mars Dust Cycle: Investigating the Effects of Radiatively Active Water Ice Clouds on Surface Stresses and Dust Lifting Potential with the NASA Ames Mars General Circulation Model

    Science.gov (United States)

    Kahre, Melinda A.; Hollingsworth, Jeffery

    2012-01-01

    The dust cycle is a critically important component of Mars' current climate system. Dust is present in the atmosphere of Mars year-round but the dust loading varies with season in a generally repeatable manner. Dust has a significant influence on the thermal structure of the atmosphere and thus greatly affects atmospheric circulation. The dust cycle is the most difficult of the three climate cycles (CO2, water, and dust) to model realistically with general circulation models. Until recently, numerical modeling investigations of the dust cycle have typically not included the effects of couplings to the water cycle through cloud formation. In the Martian atmosphere, dust particles likely provide the seed nuclei for heterogeneous nucleation of water ice clouds. As ice coats atmospheric dust grains, the newly formed cloud particles exhibit different physical and radiative characteristics. Thus, the coupling between the dust and water cycles likely affects the distributions of dust, water vapor and water ice, and thus atmospheric heating and cooling and the resulting circulations. We use the NASA Ames Mars GCM to investigate the effects of radiatively active water ice clouds on surface stress and the potential for dust lifting. The model includes a state-of-the-art water ice cloud microphysics package and a radiative transfer scheme that accounts for the radiative effects of CO2 gas, dust, and water ice clouds. We focus on simulations that are radiatively forced by a prescribed dust map, and we compare simulations that do and do not include radiatively active clouds. Preliminary results suggest that the magnitude and spatial patterns of surface stress (and thus dust lifting potential) are substantial influenced by the radiative effects of water ice clouds.

  16. Theoretical analysis of the velocity field, stress field and vortex sheet of generalized second order fluid withfractional anomalous diffusion

    Institute of Scientific and Technical Information of China (English)

    XU; Mingyu(

    2001-01-01

    generalized fractional calculus, J. Comput.Appl. Math., 2000, 118(1): 241-259.

  17. Evaluation of Inter-Specific Hybrid of P. atlantica and P. vera L. cv. ‘Badami - Riz-e-Zarand’ as Pistachio rootstock to Salinity Stress According to Some Growth Indices and Eco-physiological and Biochemical Parameters

    Directory of Open Access Journals (Sweden)

    Hamid Reza Karimi

    2014-08-01

    Full Text Available In order to evaluate the inter-specific hybrid of P. atlantica Desf. and P. vera L. cv. ‘Badami- Riz-e- Zarand’ to salinity stress, a factorial experiment was conducted based on completely randomized design with 0, 60 and 120 mM of salinity levels of sodium chloride, calcium chloride and magnesium chloride (3:2:1 with four replications on ‘Qazvini’, ‘Badami-Riz-e-Zarand’ and inter-specific of P. atlantica Ч P. vera cv. ‘Badami-Rize-Zarand’ rootstocks of pistachio. The results showed that salinity has increased proline content of leaves. Chlorophyll index, relative water content of leaf, leaf area, shoot and root fresh and dry weight, stem diameter and number of leaves were decreased by increasing salinity. Rootstocks responded differently to salinity, so that the most reduction in chlorophyll index, leaf area and leaf number were observed in ‘Badami-Riz-e-Zarand’ rootstock and the least reduction was observed in the hybrid.

  18. Hybrid Parallel Algorithm of General Sparse Matrix Multiplication%一般稀疏矩阵相乘的混合并行算法

    Institute of Scientific and Technical Information of China (English)

    罗海飙; 王婷; 张云泉

    2013-01-01

    稀疏矩阵相乘广泛应用于科学和工程计算中,是科学计算中的一种常用的基本运算,其面临着数据量大,非零值分布不规则,负载难均衡,计算结果矩阵的列指数无规则分布等问题.通过矩阵分块,优化数据传输,负载均衡,改良并行快速排序方法来解决上述问题,提高了计算效率.在多线程下计算速度比商业软件Intel MKL(Intel math kernel library)平均提高56%.同时,还通过MPI+OpenMP进行混合并行优化,在共享存储系统上两者有类似的计算速度.%Sparse matrix multiplication is widely used in scientific and engineering computations.It is a basic operation in scientific computation,but it faces many difficulties such as large data set,irregular distribution of non-zero values,load unbalancing and irregular distribution of column index of the resulting matrix.This paper optimizes matrix partitioning,data communication,load balancing and parallel sort methods to tackle the above problems.The computing speed of the algorithm improves 56% in average at multithread over commercial software Intel MKL (Intel Math Kernel Library).This paper further develops MPI+OpenMP hybrid parallel algorithm for multiprocess that achieves similar efficiency on shared memory system.

  19. Generale preventie

    NARCIS (Netherlands)

    1949-01-01

    In part I of this study a survey has veen given of what Dutch authors have written since 1870, when capital punishment was abolished, on subjects concerning the general preventive effect of punishment. This historical survey ends where, during the years 1940-1945, under the stress of the occupation

  20. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  1. 水分胁迫对玉米杂交种萌发特性和干物质生产的影响%Effect of Water Stress on Germination Characteristic and Dry Matter Production of Maize Hybrids

    Institute of Scientific and Technical Information of China (English)

    肖万欣; 赵海岩; 李明; 刘晶; 史磊; 常程; 张书萍; 汪经宏; 赵勐

    2011-01-01

    Germination characteristic at seedling stage and dry matter production and distribution in different parts under different water stress treatments of different maize hybrids through the growth season was studied in lab and greenhouse, the main results was that relative growth of germ and radicle, and storage matter transport rate of maize hybrids were downtrend, however, root cap ratio of that showed an increasing tendency with increasing of wa ter stress. Compare with other cultivars, relative growth of radicle and storage matter transport rate of Liaodan 539 were relative high at the same water stress treatment, increased rang of root cap ratio of Liaodan 539 was lager than that at normal water stress treatment(0 Mpa). Dry matter weight of different parts of maize hybrids at filling stage was ear > stem > leaf > leaf sheath > root > tassel. Compared with SS treatment, dry matter of stem decreased significantly,however,that of ear increased rapidly at CK treatment. Variation of vegetative organs/reproductive or gans dry matter ratio of Liaodan 527,Liaodan 539 and Liaodan 31 were lightly compared with other cultivars,among of them, vegetative organs/reproductive organs dry matter ratio of Liaodan 539 was relatively small. The ear dry mat ter distribution rate of Liaodan 539 was higher than that of other cultivars at different water stress treatment at filling stage,which had drought tolerant and high yield potential.%以不同玉米杂交种为试材,在实验室和温室通过设置不同水分胁迫处理,研究了供试品种萌发特性和各器官干物质生产与分配情况,主要研究结果如下,随着水分胁迫强度的增加,玉米杂交种胚芽、胚根相对生长量和储藏物质转运率均呈下降趋势,根冠比呈上升趋势.在同一水分胁迫处理下,和其他品种相比,辽单539胚根的相对生长量和储藏物质转运率均较高,根冠比比正常水分(0 MPa)处理提高幅度也较大.灌浆期,供试品种各器官干物

  2. Increased generalization of learned associations is related to re-experiencing symptoms in veterans with symptoms of post-traumatic stress.

    Science.gov (United States)

    Anastasides, Nicole; Beck, Kevin D; Pang, Kevin C H; Servatius, Richard J; Gilbertson, Mark W; Orr, Scott P; Myers, Catherine E

    2015-01-01

    One interpretation of re-experiencing symptoms in post-traumatic stress disorder (PTSD) is that memories related to emotional information are stored strongly, but with insufficient specificity, so that stimuli which are minimally related to the traumatic event are sufficient to trigger recall. If so, re-experiencing symptoms may reflect a general bias against encoding background information during a learning experience, and this tendency might not be limited to learning about traumatic or even autobiographical events. To test this possibility, we administered a discrimination-and-transfer task to 60 Veterans (11.2% female, mean age 54.0 years) self-assessed for PTSD symptoms in order to examine whether re-experiencing symptoms were associated with increased generalization following associative learning. The discrimination task involved learning to choose the rewarded object from each of six object pairs; each pair differed in color or shape but not both. In the transfer phase, the irrelevant feature in each pair was altered. Regression analysis revealed no relationships between re-experiencing symptoms and initial discrimination learning. However, re-experiencing symptom scores contributed to the prediction of transfer performance. Other PTSD symptom clusters (avoidance/numbing, hyperarousal) did not account for significant additional variance. The results are consistent with an emerging interpretation of re-experiencing symptoms as reflecting a learning bias that favors generalization at the expense of specificity. Future studies will be needed to determine whether this learning bias may pre-date and confer risk for, re-experiencing symptoms in individuals subsequently exposed to trauma, or emerges only in the wake of trauma exposure and PTSD symptom development.

  3. Assignment of the human stress-activated protein kinase-3 gene (SAPK3) to chromosome 22q13.3 by fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Goedert, M.; Hasegawa, J.; Craxton, M. [MRC Lab. of Molecular Biology, Cambridge, MA (United States)] [and others

    1997-05-01

    Three mitogen-activated protein (MAP) kinase family members have been identified in mammalian cells that are activated by cellular stresses, by bacterial lipopolysaccharide, and by the cytokines interleukin-1 and tumor necrosis factor and have therefore been called stress-activated protein kinases (SAPKs). SAPK1, SAPK2A (also known as p38, RK, and CSBP), and SAPK2B are activated by upstream kinases and in turn phosphorylate downstream substrates, such as other protein kinases and a number of transcription factors. 12 refs., 1 fig.

  4. A Hybrid Architecture Approach for Quantum Algorithms

    Directory of Open Access Journals (Sweden)

    Mohammad R.S. Aghaei

    2009-01-01

    Full Text Available Problem statement: In this study, a general plan of hybrid architecture for quantum algorithms is proposed. Approach: Analysis of the quantum algorithms shows that these algorithms were hybrid with two parts. First, the relationship of classical and quantum parts of the hybrid algorithms was extracted. Then a general plan of hybrid structure was designed. Results: This plan was illustrated the hybrid architecture and the relationship of classical and quantum parts of the algorithms. This general plan was used to increase implementation performance of quantum algorithms. Conclusion/Recommendations: Moreover, simulation results of quantum algorithms on the hybrid architecture proved that quantum algorithms can be implemented on the general plan as well.

  5. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  6. Effect of the Volume Fraction of Jute Fiber on the Interlaminar Shear Stress and Tensile Behavior Characteristics of Hybrid Glass/Jute Fiber Reinforced Polymer Composite Bar for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Chan-Gi Park

    2016-01-01

    Full Text Available Hybrid glass/jute fiber reinforced polymer (HGJFRP composite bars were manufactured for concrete structures, and their interlaminar shear stress and tensile performance were evaluated. HGJFRP composite bars were manufactured using a combination of pultrusion and braiding processes. Jute fiber was surface-treated with a silane coupling agent. The mixing ratio of the fiber to the vinyl ester used in the HGJFRP composite bars was 7 : 3. Jute fiber was used to replace glass fiber in proportions of 0, 30, 50, 70, and 100%. The interlaminar shear stress decreased as the proportion of jute fiber increased. Fractures appeared due to delamination between the surface-treated component and the main part of the HGJFRP composite bar. Tensile load-strain curves with 50% jute fiber exhibited linear behavior. With a jute fiber volume fraction of 70%, some plastic deformation occurred. A jute fiber mixing ratio of 100% resulted in a display of linear elastic brittle behavior from the fiber; however, when the surface of the fiber was coated with poly(vinyl acetate, following failure, the jute fiber exhibited partial load resistance. The tensile strength decreased as the jute fiber content increased; however, the tensile strength did not vary linearly with jute fiber content.

  7. Stress and stressors in the clinical environment: a comparative study of fourth-year student nurses and newly qualified general nurses in Ireland.

    LENUS (Irish Health Repository)

    Suresh, Patricia

    2013-03-01

    To measure and compare the perceived levels of job-related stress and stressors of newly qualified nurses and fourth-year student nurses in the clinical environment and to explore the participants\\' views on stress and stressors.

  8. Residual stresses in cross-ply composite tubes

    Science.gov (United States)

    Cohen, D.; Hyer, M. W.

    1984-01-01

    The residual thermal stresses in 4-layer cross-ply tubes are studied. The tubes considered has a small radius to wall-thickness ratios and so elasticity solutions were used. The residual thermal stress problem was considered to be axisymmetric and three elasticity solutions were derived and the results compared with the results using classical lamination theory. The comparison illustrates the limitations of classical lamination theory. The three elasticity solutions derived were: plane stress, plane strain, and generalized plane strain, the latter being the most realistic. Residual stresses in both the hoop and axial direction is significant. Stacking arrangement effects the residual stress to some extent, as do the material properties of the individual lamina. The benefits of hybrid construction are briefly discussed.

  9. How Is Examination Stress Experienced by Secondary Students Preparing for Their General Certificate of Secondary Education Examinations and How Can It Be Explained?

    Science.gov (United States)

    Putwain, David William

    2011-01-01

    High stakes examinations have been identified as a significant source of stress for secondary school students; however, there is little data accounting for, and explaining, the experiences of examination stress. This study aimed to further the understanding of examination stress in secondary school students by conducting interviews with 34…

  10. Procedural validity of the AUDADIS-5 depression, anxiety and post-traumatic stress disorder modules: substance abusers and others in the general population*

    Science.gov (United States)

    Hasin, Deborah S.; Shmulewitz, Dvora; Stohl, Malka; Greenstein, Eliana; Aivadyan, Christina; Morita, Kara; Saha, Tulshi; Aharonovich, Efrat; Jung, Jeesun; Zhang, Haitao; Nunes, Edward V.; Grant, Bridget F.

    2016-01-01

    Background Little is known about the procedural validity of lay-administered, fully-structured assessments of depressive, anxiety and post-traumatic stress (PTSD) disorders in the general population as determined by comparison to clinical re-appraisal, and whether this differs between current regular substance abusers and others. We evaluated the procedural validity of the Alcohol Use Disorder and Associated Disabilities Interview Schedule, DSM-5 Version (AUDADIS-5) assessment of these disorders through clinician re-interviews. Methods Test-retest design among respondents from the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III): (264 current regular substance abusers, 447 others). Clinicians blinded to AUDADIS-5 results administered the semi-structured Psychiatric Research Interview for Substance and Mental Disorders, DSM-5 version (PRISM-5). AUDADIS-5/PRISM-5 concordance was indicated by kappa (κ) for diagnoses and intraclass correlation coefficients (ICC) for dimensional measures (DSM-5 symptom or criterion counts). Results were compared between current regular substance abusers and others. Results AUDADIS-5 and PRISM-5 concordance for DSM-5 depressive disorders, anxiety disorders and PTSD was generally fair to moderate (κ =0.24–0.59), with concordance on dimensional scales much better (ICC=0.53–0.81). Concordance differed little between regular substance abusers and others. Conclusions AUDADIS-5/PRISM-5 concordance indicated procedural validity for the AUDADIS-5 among substance abusers and others, suggesting that AUDADIS-5 diagnoses of DSM-5 depressive, anxiety and PTSD diagnoses are informative measures in both groups in epidemiologic studies. The stronger concordance on dimensional measures supports the current movement towards dimensional psychopathology measures, suggesting that such measures provide important information for research in the NESARC-III and other datasets, and possibly for clinical purposes as well. PMID

  11. Sensitivity to stress-induced reproductive dysfunction is associated with a selective but not a generalized increase in activity of the adrenal axis.

    Science.gov (United States)

    Herod, S M; Dettmer, A M; Novak, M A; Meyer, J S; Cameron, J L

    2011-01-01

    Stress-induced reproductive dysfunction is a relatively common cause of infertility in women. In response to everyday life stress, some individuals readily develop reproductive dysfunction (i.e., they are stress sensitive), whereas others are more stress resilient. Female cynomolgus monkeys, when exposed to mild combined psychosocial and metabolic stress (change in social environment + 20% reduced calorie diet), can be categorized as stress sensitive (SS; they rapidly become anovulatory in response to stress), medium stress resilient (MSR; they slowly become anovulatory in response to prolonged stress), or highly stress resilient (HSR; they maintain normal menstrual cycles in response to stress). In this study, we examined whether increased sensitivity to stress-induced reproductive dysfunction is associated with elevated adrenal axis activity by measuring 1) the diurnal release of ACTH and cortisol, 2) ACTH and cortisol in response to an acute psychological stress, 3) the percent suppression of cortisol in response to dexamethasone negative feedback, 4) the diurnal release of ACTH and cortisol following exposure to mild psychosocial and metabolic stress, 5) the concentration of cortisol in hair, and 6) adrenal weight. SS monkeys (n = 5) did not differ from MSR (n = 5) or HSR (n = 7) monkeys in any measurement of baseline HPA axis activity or the integrated measurements of chronic HPA axis activity. However, MSR + SS monkeys (n = 10) did secrete more cortisol than HSR monkeys during the daytime hours (1000-1800) following exposure to a novel social environment and reduced diet. We conclude that increased activity of the HPA axis is unlikely to be the primary mechanism causing increased sensitivity to stress-induced reproductive dysfunction.

  12. Gene expression and yeast two-hybrid studies of transcription factors mediating drought stress response in root tissues of chickpea (Cicer arietinum L.

    Directory of Open Access Journals (Sweden)

    Abirami eRamalingam

    2015-12-01

    Full Text Available Drought stress has been one of the serious constraints affecting chickpea productivity to a great extent. Genomic assisted breeding in chickpea has been effective in providing a yield advantage of up to 24 %, thus having a potential to accelerate breeding precisely and efficiently. In order to do so, understanding the molecular mechanisms for drought tolerance and identification of candidate genes are crucial. Transcription factors (TFs have important roles in the regulation of plant stress related genes. In this context, quantitative real time-PCR (qRT-PCR was used to study the differential gene expression of selected TFs, identified from large-scale gene expression analysis, in contrasting drought responsive genotypes. Root tissues of ICC 4958 (tolerant, ICC 1882 (sensitive, JG 11 (elite and JG 11+ (introgression line were used for the study. Subsequently, a candidate single repeat MYB gene (1R-MYB that was remarkably induced in the drought tolerant genotypes under drought stress was cloned and subjected to Y2H analysis by screening a root cDNA library. The protein-protein interaction study identified three interacting peptides, a galactinol-sucrose galactosyltransferase 2, a CBL (Calcineurin B-like-interacting serine/threonine-protein kinase 25 and an ABA responsive 17-like, which were confirmed by the co-transformation of candidate plasmids in yeast. These findings provide preliminary insights into the ability of 1R-MYB TF to co-regulate drought tolerance mechanism in chickpea roots.

  13. Effects of general anesthesia on stress response and inflammatory cytokines in elderly patients undergoing abdominal surgery under the guidance of Narcotrend

    Institute of Scientific and Technical Information of China (English)

    Da-Yong Lin; Yan-Xin Liu; Qian Li

    2016-01-01

    Objective:To investigate the effect of general anesthesia on stress response and inflammatory cytokines in elderly patients undergoing abdominal surgery under the guidance of Narcotrend. Methods:A total of 150 elderly patients with abdominal surgery in our hospital from January 2015 to December 2015 were randomly divided into three groups: D0, D2 and E2 group, each 50 cases. With different depth of anesthesia, the stress response indexes COR, ACTH, CRP and ET-1, the inflammatory factors IL-6 and TNF-α before anesthesia, postoperative 1 h and postoperative 1 d were compared.Results:The differences of Cor, ACTH, CRP and ET-1 in the three groups D0, D2 and E2 were all statistically significant (P<0.05); the differences of Cor, ACTH and CRP at each time point were also statistically significant (P<0.05), Cor in D0 and D2 group were significantly increased postoperative 1 h and 1 d (P<0.05), ACTH in D0, D2 and E2 group were significantly increased postoperative 1 h and 1 d (P<0.05), CRP in D0 group was significantly increased postoperative 1 h and 1 d (P<0.05); The increase amplitude of Cor in D0 and D2 group at each time point was higher than in E2 group (P<0.05), the increase amplitude of ACTH in D2 group at each time point was lower than in D0 and E2 group (P<0.05), the increase amplitude of CRP in D0 group at each time point was higher than in D2 and E2 group (P<0.05), ET-1 in D0 and D2 group had no changes at each time point, while the decrease amplitude of ET-1 in E2 group at each time point was significantly higher than in D0 and D2 group (P<0.05). The differences of IL-6 and TNF-α in the three groups D0, D2 and E2 were all statistically significant (P<0.05); the differences of IL-6 and TNF-α at each time point were also statistically significant (P<0.05), IL-6 and TNF-α in D0 group were significantly increased postoperative 1 h and 1 d (P < 0.05); the increase amplitude of IL-6 and TNF-α in D0 group at each time point was higher than in D2 and E2 group (P<0

  14. A Chinese Herbal Formula to Improve General Psychological Status in Posttraumatic Stress Disorder: A Randomized Placebo-Controlled Trial on Sichuan Earthquake Survivors

    Directory of Open Access Journals (Sweden)

    Xian-Ze Meng

    2012-01-01

    Full Text Available Introduction. Posttraumatic stress disorder (PTSD is accompanied by poor general psychological status (GPS. In the present study, we investigated the effects of a Chinese herbal formula on GPS in earthquake survivors with PTSD. Methods. A randomized, double-blind, placebo-controlled trial compared a Chinese herbal formula, Xiao-Tan-Jie-Yu-Fang (XTJYF, to placebo in 2008 Sichuan earthquake survivors with PTSD. Patients were randomized into XTJYF (n=123 and placebo (n=122 groups. Baseline-to-end-point score changes in the three global indices of the Symptom Checklist-90-Revised (SCL-90-R and rates of response in the SCL global severity index (GSI were the primary endpoints. A subanalysis of the nine SCL factors and the sleep quality score were secondary endpoints. Results and Discussion. Compared to placebo, the XTJYF group was significantly improved in all three SCL global indices (P = 0.001~0.028. More patients in the XTJYF group reported “much improved” than the placebo group (P = 0.001. The XTJYF group performed significantly better than control in five out of nine SCL factors (somatization, obsessive-compulsive behavior, depression, anxiety, and hostility (P = 0.001~0.036, and in sleep quality score (P<0.001. XTJYF produced no serious adverse events. These findings suggest that XTJYF may be an effective and safe treatment option for improving GPS in patients with PTSD.

  15. Pressure calculation in hybrid particle-field simulations.

    Science.gov (United States)

    Milano, Giuseppe; Kawakatsu, Toshihiro

    2010-12-07

    In the framework of a recently developed scheme for a hybrid particle-field simulation techniques where self-consistent field (SCF) theory and particle models (molecular dynamics) are combined [J. Chem. Phys. 130, 214106 (2009)], we developed a general formulation for the calculation of instantaneous pressure and stress tensor. The expressions have been derived from statistical mechanical definition of the pressure starting from the expression for the free energy functional in the SCF theory. An implementation of the derived formulation suitable for hybrid particle-field molecular dynamics-self-consistent field simulations is described. A series of test simulations on model systems are reported comparing the calculated pressure with those obtained from standard molecular dynamics simulations based on pair potentials.

  16. Hybrid guiding-centre/full-orbit simulations in non-axisymmetric magnetic geometry exploiting general criterion for guiding-centre accuracy

    CERN Document Server

    Pfefferlé, David; Cooper, Wilfred A

    2014-01-01

    To identify under what conditions guiding-centre or full-orbit tracing should be used, an estimation of the spatial variation of the magnetic field is proposed, not only taking into account gradient and curvature terms but also the local shear of the field-lines. The criterion is derived for general three-dimensional magnetic equilibria including stellarator plasmas. Details are provided on how to implement it in cylindrical coordinates and in flux coordinates that rely on the geometric toroidal angle. A means of switching between guiding-centre and full-orbit equations at first order in Larmor radius with minimal discrepancy is shown. Techniques are applied to a MAST (Mega Amp Spherical Tokamak) helical core equilibrium in which the inner kinked flux-surfaces are tightly compressed against the outer axisymmetric mantle and where the parallel current peaks at the nearly rational surface. This is put in relation to the simpler situation $\\vec{B}(x,y,z) = B_0 [\\sin(kx) \\vec{e_y} + \\cos(kx)\\vec{e_z}]$, for which...

  17. Prediction of vertical PM2.5 concentrations alongside an elevated expressway by using the neural network hybrid model and generalized additive model

    Science.gov (United States)

    Gao, Ya; Wang, Zhanyong; Lu, Qing-Chang; Liu, Chao; Peng, Zhong-Ren; Yu, Yue

    2016-10-01

    A study on vertical variation of PM2.5 concentrations was carried out in this paper. Field measurements were conducted at eight different floor heights outside a building alongside a typical elevated expressway in downtown Shanghai, China. Results show that PM2.5 concentration decreases significantly with the increase of height from the 3rd to 7th floor or the 8th to 15th floor, and increases suddenly from the 7th to 8th floor which is the same height as the elevated expressway. A non-parametric test indicates that the data of PM2.5 concentration is statistically different under the 7th floor and above the 8th floor at the 5% significance level. To investigate the relationships between PM2.5 concentration and influencing factors, the Pearson correlation analysis was performed and the results indicate that both traffic and meteorological factors have crucial impacts on the variation of PM2.5 concentration, but there is a rather large variation in correlation coefficients under the 7th floor and above the 8th floor. Furthermore, the back propagation neural network based on principal component analysis (PCA-BPNN), as well as generalized additive model (GAM), was applied to predict the vertical PM2.5 concentration and examined with the field measurement dataset. Experimental results indicated that both models can obtain accurate predictions, while PCA-BPNN model provides more reliable and accurate predictions as it can reduce the complexity and eliminate data co-linearity. These findings reveal the vertical distribution of PM2.5 concentration and the potential of the proposed model to be applicable to predict the vertical trends of air pollution in similar situations.

  18. Effects of Acid Rain Stress on Antioxidant Enzyme Activity and Chlorophyll Fluorescence in Leaves of Gazania Hybrids%酸雨对勋章菊保护酶活性及叶绿素荧光参数的影响

    Institute of Scientific and Technical Information of China (English)

    侯维; 潘远智

    2013-01-01

    In this paper,pot experiments were conducted to study the effect of simulated acid rain that included four different pH values (5.6,4.5,3.5,2.5) on the membrane permeability,malondialdehyde (MDA) content and antioxidant enzyme activity,chlorophyll (Chl) content,and chlorophyll fluorescence in of leaves Gazania Hybrids.The membrane permeability and MDA content increased significantly after acid rain stress and with an extremely significant correlation between them.The dismutase (SOD),catalase (CAT) and peroxidase (POD) activities were showed a single-peak curve which was firstly increased and then decreased,and the maximum activity of SOD,CAT and POD were observed at pH4.5.Chl a,Chl b,total chlorophyll content,Chl a/b,the PS Ⅱ photochemical efficiency (Fv/ Fm) and the PS Ⅱ potential activity (Fv/Fo),actual PS Ⅱ photochemical quantum yield (ΦpsⅡ) and qP decreased accordingly with the decreasing of pH value,while qN increased.The study showed that G.Hybrids has strong resistance to acid rain stress and the visible damage threshold was less than pH 3.5.Therefore,G.Hybrids can be considered as one of the landscaping and vegetation constructing plants in the acid rain-hit areas.%采用盆栽方法,以不同pH值(5.6、4.5、3.5、2.5)的模拟酸雨胁迫试验,探讨其对勋章菊(Gazania Hybrids)叶片质膜透性、MDA含量、保护酶活性、叶绿素含量及叶绿素荧光参数的影响.结果表明,随pH值的降低,勋章菊叶片质膜透性和MDA含量呈逐渐升高的趋势,且二者呈显著正相关;SOD、CAT和POD活性呈先升高后下降的单峰曲线变化,其中SOD、CAT和POD活性最大值均出现在pH4.5处理;叶绿素a、叶绿素b、叶绿素a+b的含量、叶绿素a/b、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ的潜在活性(Fv/Fo)、PSⅡ实际光化学量子产量(Φps.Ⅱ)、光化学淬灭系数(qP)均随pH值的降低而下降,非光化学淬灭系数(qN)随pH值的降低而升高.模拟酸雨对勋章菊叶片

  19. Completeness in Hybrid Type Theory

    DEFF Research Database (Denmark)

    Areces, Carlos; Blackburn, Patrick Rowan; Huertas, Antonia;

    2014-01-01

    We show that basic hybridization (adding nominals and @ operators) makes it possible to give straightforward Henkin-style completeness proofs even when the modal logic being hybridized is higher-order. The key ideas are to add nominals as expressions of type t, and to extend to arbitrary types...... the way we interpret @i in propositional and first-order hybrid logic. This means: interpret @iαa , where αa is an expression of any type a , as an expression of type a that rigidly returns the value that αa receives at the i-world. The axiomatization and completeness proofs are generalizations of those...

  20. Spatial Self-Organization of Vegetation Subject to Climatic Stress-Insights from a System Dynamics-Individual-Based Hybrid Model.

    Science.gov (United States)

    Vincenot, Christian E; Carteni, Fabrizio; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

    2016-01-01

    In simulation models of populations or communities, individual plants have often been obfuscated in favor of aggregated vegetation. This simplification comes with a loss of biological detail and a smoothing out of the demographic noise engendered by stochastic individual-scale processes and heterogeneities, which is significant among others when studying the viability of small populations facing challenging fluctuating environmental conditions. This consideration has motivated the development of precise plant-centered models. The accuracy gained in the representation of plant biology has then, however, often been balanced by the disappearance in models of important plant-soil interactions (esp. water dynamics) due to the inability of most individual-based frameworks to simulate complex continuous processes. In this study, we used a hybrid modeling approach, namely integrated System Dynamics (SD)-Individual-based (IB), to illustrate the importance of individual plant dynamics to explain spatial self-organization of vegetation in arid environments. We analyzed the behavior of this model under different parameter sets either related to individual plant properties (such as seed dispersal distance and reproductive age) or the environment (such as intensity and yearly distribution of precipitation events). While the results of this work confirmed the prevailing theory on vegetation patterning, they also revealed the importance therein of plant-level processes that cannot be rendered by reaction-diffusion models. Initial spatial distribution of plants, reproductive age, and average seed dispersal distance, by impacting patch size and vegetation aggregation, affected pattern formation and population survival under climatic variations. Besides, changes in precipitation regime altered the demographic structure and spatial organization of vegetation patches by affecting plants differentially depending on their age and biomass. Water availability influenced non-linearly total

  1. Military Hybrid Vehicle Survey

    Science.gov (United States)

    2011-08-03

    Furthermore, a standard duty cycle that is accepted for measuring fuel economy does not exist nor does a focus towards a particular technology. This...expanded into mild hybrid with the addition of a clutch connecting the generator to the transmission and additional energy storage [16-17...speed control and one for engine/generator torque [35]. Urban, Highway, Composite 33%, 27.9%, 49% General vehicle simulation [30]. Urban 19.0

  2. Formal Description of Hybrid Systems

    DEFF Research Database (Denmark)

    Zhou, Chaochen; Ji, Wang; Ravn, Anders P.

    1996-01-01

    A language to describe hybrid systems, i.e. networks of communicating discrete and continuous processes, is proposed. A semantics of the language is given in Extended Duration Calculus, a real-time interval logic with a proof system that allows reasoning in mathematical analysis about continuous ...... processes to be embedded into the logic. The semantics thus provides a secure link to hybrid system models based on a general theory of dynamical systems....

  3. A global hybrid coupled model based on Atmosphere-SST feedbacks

    CERN Document Server

    Cimatoribus, Andrea A; Dijkstra, Henk A

    2011-01-01

    A global hybrid coupled model is developed, with the aim of studying the effects of ocean-atmosphere feedbacks on the stability of the Atlantic meridional overturning circulation. The model includes a global ocean general circulation model and a statistical atmosphere model. The statistical atmosphere model is based on linear regressions of data from a fully coupled climate model on sea surface temperature both locally and hemispherically averaged, being the footprint of Atlantic meridional overturning variability. It provides dynamic boundary conditions to the ocean model for heat, freshwater and wind-stress. A basic but consistent representation of ocean-atmosphere feedbacks is captured in the hybrid coupled model and it is more than ten times faster than the fully coupled climate model. The hybrid coupled model reaches a steady state with a climate close to the one of the fully coupled climate model, and the two models also have a similar response (collapse) of the Atlantic meridional overturning circulati...

  4. Impact of water temperature and sodium chloride (NaCl on stress indicators of hybrid catfish (Clarias gariepinus Burchell x C. macrocephalus Gunther

    Directory of Open Access Journals (Sweden)

    Weena Koeypudsa

    2011-08-01

    Full Text Available This research was composed of 2 experiments. Short-term (1 day and long-term (30 days exposure were conductedin the laboratory. Each experiment had 2 temperature levels, high (Ht, 29.5 ± 0.5C and low temperature (Lt, 19.5 ± 0.5C.Initial weight and length of catfish were 7.54±1.82 g and 9.90±0.96 cm respectively. Experimental catfish were subjected to 4conditions as follows: high temperature with 0.1% sodium chloride (HtWs, high temperature without 0.1% sodium chloride(HtW/s, low temperature with 0.1% sodium chloride (LtWs, and low temperature without 0.1% sodium chloride (LtW/s.Blood was taken from caudal vessel of anaesthetized fish to investigate blood clotting time, cortisol, glucose, osmolarity,Na+, K+ and Cl-. Ratios of Na+/K+, Na+/Cl- and Na+ + K+ / Cl- were also analyzed. In the short-term (1 day experiment, values ofall catfish blood parameters varied. These imply that catfish attempt to maintain internal balance, homeostasis. Osmolarityexhibited complete homeostasis in 2 h. From long-term (30 days exposure, non-significant means of Na+/Cl- ratio (HtWsand decreasing trend lines direction of blood clotting time (HtWs, LtW/s, LtWs indicated that 0.1% sodium chloride and/orLt helped stress reduction in catfish. Sum of Na+ and K+ to Cl- ratio among 4 groups (HtW/s, HtWs, LtW/s, LtWs revealedthat catfish spent 10 days for adjustment themselves under stress circumstance (HtWs, LtW/s, LtWs to natural situation(HtW/s. This information could be useful to improve the survival rate and health condition during rearing, handling andtransporting aquatic animals.

  5. Oxidative stress

    Directory of Open Access Journals (Sweden)

    Osredkar Joško

    2012-05-01

    Full Text Available The human organism is exposed to the influence of various forms of stress, either physical, psychological or chemical, which all have in common that they may adversely affect our body. A certain amount of stress is always present and somehow directs, promotes or inhibits the functioning of the human body. Unfortunately, we are now too many and too often exposed to excessive stress, which certainly has adverse consequences. This is especially true for a particular type of stress, called oxidative stress. All aerobic organisms are exposed to this type of stress because they produce energy by using oxygen. For this type of stress you could say that it is rather imperceptibly involved in our lives, as it becomes apparent only at the outbreak of certain diseases. Today we are well aware of the adverse impact of radicals, whose surplus is the main cause of oxidative stress. However, the key problem remains the detection of oxidative stress, which would allow us to undertake timely action and prevent outbreak of many diseases of our time. There are many factors that promote oxidative stress, among them are certainly a fast lifestyle and environmental pollution. The increase in oxidative stress can also trigger intense physical activity that is directly associated with an increased oxygen consumption and the resulting formation of free radicals. Considering generally positive attitude to physical activity, this fact may seem at first glance contradictory, but the finding has been confimed by several studies in active athletes. Training of a top athlete daily demands great physical effort, which is also reflected in the oxidative state of the organism. However, it should be noted that the top athletes in comparison with normal individuals have a different defense system, which can counteract the negative effects of oxidative stress. Quite the opposite is true for irregular or excessive physical activity to which the body is not adapted.

  6. Faulted hybrid joints: an example from the Campo de Dalias (Betic Cordilleras, Spain)

    Science.gov (United States)

    Marín-Lechado, Carlos; Galindo-Zaldívar, Jesús; Rodríguez-Fernández, Luís. Roberto; González-Lodeiro, Francisco

    2004-11-01

    The development of hybrid and faulted joints has not been studied in detail in natural outcrops. This field study in the Campo de Dalias (Betic Cordilleras) establishes the distinctive features of these structures as compared with those predicted by theoretical studies. Hybrid joints appear as two sets of vertical joints forming variable angles, but generally about 25°, with opening directions orthogonal to joint planes. Their development requires low differential stresses with a tensile minimum stress. The main criteria that indicate the existence of faulted joints are: (1) the presence of subvertical fault planes with oblique slip forming a complex pattern of dextral and sinistral faults developed under a single stress regime; (2) faults with similar geometries as joints in the same outcrop, showing an inconsistent cross-cutting relationship; and (3) the development of small basins with variable polarity of asymmetric wedge filling. A permutation in stress orientation since the Tortonian in the Campo de Dalias was responsible for the development of a faulted hybrid joint system, with a constant ENE-WSW extension trend and a switch of σ1 between NNW-SSE and vertical.

  7. Bundled Hybrid Offset Riser Global Strength Analysis

    Institute of Scientific and Technical Information of China (English)

    William C.Webster; Zhuang Kang; Wenzhou Liang; Youwei Kang; Liping Sun

    2011-01-01

    Bundled hybrid offset riser(BHOR)global strength analysis,which is more complex than single line offset riser global strength analysis,was carried out in this paper.At first,the equivalent theory is used to deal with BHOR,and then its global strength in manifold cases was analyzed,along with the use of a three-dimensional nonlinear time domain finite element program.So the max bending stress,max circumferential stress,and max axial stress in the BHOR bundle main section(BMS)were obtained,and the values of these three stresses in each riser were obtained through the "stress distribution method".Finally,the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand.This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.

  8. Analysis and application of B-spline wavelet on interval hybrid stress element%区间B样条小波杂交应力元分析及其应用

    Institute of Scientific and Technical Information of China (English)

    刘艳红; 商中新

    2013-01-01

    Wavelet function is introduced into hybrid stress element. The scaling functions of BSWI are used to construct the rectangular and cubic wavelet element as interpolation function. The results obtained in this paper are compared with those by Abaqus. The numerical examples illustrate that the wavelet-based element method has higher accuracy and higher accuracy, while it's less sensitive to the density of elements.%将小波函数引入到杂交应力元中,以其尺度函数作为插值函数,构造了二维四节点和三维八节点的B样条小波杂交应力元.将数值算例结果与理论解和Abaqus软件计算结果相对比,本文所构造的新型单元具有计算精度高、对单元划分密度不敏感、收敛速度快的优点.

  9. An intercomparison of measured and modeled canopy parameters during the variable water-stressed period of FIFE 1989 using an hybrid biosphere-remote sensing model

    Science.gov (United States)

    Cooper, H. J.; Crosson, W. L.; Smith, E. A.

    1992-01-01

    The measured atmospheric parameters and the fluxes of latent and sensible heat across the biosphere-atmosphere interface collected during the water-stressed period of the First ISLSCP Field Experiment (FIFE) were compared with those calculated by an experimental version of the Biosphere-Atmosphere Transfer Scheme (Ex-BATS). It is shown that the brightness temperature (T(B)) values observed near the surface during FIFE 1987 are closely correlated to in-canopy temperatures calculated by Ex-BATS. The 1987 near-surface observations of T(B) are also well correlated to AVHHR channels 4 and 5 measurements. An inverted form of Ex-BATS was applied to determine the associated required in-canopy temperatures, T(icr), and regressions between T(icr) and T(B) found from the 1987 data were applied to the 1989 observed T(B) at a different site. The T(icr) so estimated showed excellent correlation to the 1989 model calculated T(icr).

  10. The Power of Hybridization

    CERN Document Server

    CERN. Geneva

    2011-01-01

    Programming languages always seem to do some things well but not others: Python punts when it comes to user interfaces, Java’s artificial complexity prevents rapid development and produces tangles, and it will be awhile before we see benefits from C++ concurrency work. The cognitive load of languages and their blind spots increases the cost of experimentation, impeding your ability to fail fast and iterate. If you use a single language to solve your problem, you are binding yourself to the worldview limitations and the mistakes made by the creator of that language. Consider increasing your wiggle room by crossing language boundaries, complementing a language that is powerful in one area with a different language powerful in another. Language hybridization can speed development to quickly discover your real problems, giving you more time to fix them. After making a case for hybridizing your thinking in general, I will present a number of simple examples; first showing the benefits of using other languages...

  11. Hybrid microelectronic technology

    Science.gov (United States)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  12. 广义有效应力在非饱和土本构模型中的应用%Application of Generalized Effective Stress in Constitutive Model of Unsaturated Soil

    Institute of Scientific and Technical Information of China (English)

    付科; 张林洪; 邢万鹏

    2012-01-01

    In order to accurately define and understand the Bishop's stress, the definition framework of generalized effective stress is put forward by considering the shortcomings of constitutive model of unsaturated soil. And then it compares with the traditional definition framework of the Bishop's stress. Finally, the matric suction, cementation action and hardening process are discussed.%为更好地定义和理解毕肖普(Bishop)应力,针对非饱和土本构模型有效应力研究中存在的问题,提出 了广义有效应力定义框架,并与传统Bishop应力定义框架做了比较,探讨了基质吸力、粘固作用、硬化过程.

  13. Generalized derivations and general relativity

    CERN Document Server

    Heller, M; Pysiak, L; Sasin, W

    2013-01-01

    We construct differential geometry (connection, curvature, etc.) based on generalized derivations of an algebra A. Such a derivation, introduced by Bresar in 1991, is given by a linear mapping u: A -> A such that there exists a usual derivation d of A satisfying the generalized Leibniz rule u(a b) = u(a) b + a d(b) for all a,b in A. The generalized geometry "is tested" in the case of the algebra of smooth functions on a manifold. We then apply this machinery to study the generalized general relativity. We define the Einstein-Hilbert action and deduce from it Einstein's field equations. We show that for a special class of metrics containing, besides the usual metric components, only one non-zero term, the action reduces to O'Hanlon action that is a Brans-Dicke action with potential and with the parameter \\omega equal to zero. We also show that the generalized Einstein equations (with zero energy-stress tensor) are equivalent to those of the Kaluza-Klein theory satisfying a "modified cylinder condition" and hav...

  14. Hybrid Dynamical Systems Modeling, Stability, and Robustness

    CERN Document Server

    Goebel, Rafal; Teel, Andrew R

    2012-01-01

    Hybrid dynamical systems exhibit continuous and instantaneous changes, having features of continuous-time and discrete-time dynamical systems. Filled with a wealth of examples to illustrate concepts, this book presents a complete theory of robust asymptotic stability for hybrid dynamical systems that is applicable to the design of hybrid control algorithms--algorithms that feature logic, timers, or combinations of digital and analog components. With the tools of modern mathematical analysis, Hybrid Dynamical Systems unifies and generalizes earlier developments in continuous-time and discret

  15. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  16. Hybrid Qualifications

    DEFF Research Database (Denmark)

    has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...... masters», i.e. by producing skills for the labour market and enabling individuals to progress more or less directly to higher education. The specific focus of this book is placed on conditions, structures and processes which help to combine VET with qualifications leading into higher education...

  17. Cryopreservation of Bituminaria bituminosa varieties and hybrids

    OpenAIRE

    Gisbert Domenech, Maria Carmen; Dabauza, Mercedes; Correal, Enrique; Swennen, Rony; Panis, Bart

    2015-01-01

    [EN] Bituminaria bituminosa (L.) C.H. Stirton is a drought tolerant, perennial legume pasture species and a source of pharmaceutical compounds. Bituminaria breeding programs aim to develop and conserve hybrids with desirable traits such as high forage quality, tolerance to biotic or abiotic stresses, and high contents of furanocoumarins. In this work we present a cryopreservation study of different B. bituminosa accessions: two varieties and eight intervarietal hybrids resulting f...

  18. 自我效能感对心理弹性影响的实证研究%An Empirical Study of Effects of General and Regulatory Emotional Self-Efficacy on Stress Resilience

    Institute of Scientific and Technical Information of China (English)

    刘燊; 李丹丹; 张林

    2015-01-01

    This paper investigated 300 undergraduates in questionnaire to examine the effects of general self-efficacy and regulatory emotional self-efficacy on stress resilience. The results showed that there were significantly positive correlations between general self-efficacy, regulatory emotional self-efficacy and stress resilience; and regulatory emotional self-efficacy completely mediated the relationship between general self-efficacy and stress resilience.%运用问卷调查法,以300名大学生为研究对象,探讨一般自我效能感和情绪调节自我效能感对大学生心理弹性的影响。研究发现:一般自我效能感与情绪调节自我效能感、心理弹性之间均有显著的正相关,情绪调节自我效能感与心理弹性之间有显著的正相关;情绪调节自我效能感在一般自我效能感对心理弹性的影响之间具有完全中介作用。

  19. Forces in General Relativity

    Science.gov (United States)

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  20. Forces in General Relativity

    Science.gov (United States)

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  1. Mechanical property characterization of intraply hybrid composites

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sinclair, J. H.

    1979-01-01

    An investigation of the mechanical properties of intraply hybrids made from graphite fiber/epoxy matrix hybridized with secondary S-glass or Kevlar 49 fiber composites is presented. The specimen stress-strain behavior was determined, showing that mechanical properties of intraply hybrid composites can be measured with available methods such as the ten-degree off-axis test for intralaminar shear, and conventional tests for tensile, flexure, and Izod impact properties. The results also showed that combinations of high modulus graphite/S-glass/epoxy matrix composites exist which yield intraply hybrid laminates with the best 'balanced' properties, and that the translation efficiency of mechanical properties from the constituent composites to intraply hybrids may be assessed with a simple equation.

  2. Hybrid soft computing approaches research and applications

    CERN Document Server

    Dutta, Paramartha; Chakraborty, Susanta

    2016-01-01

    The book provides a platform for dealing with the flaws and failings of the soft computing paradigm through different manifestations. The different chapters highlight the necessity of the hybrid soft computing methodology in general with emphasis on several application perspectives in particular. Typical examples include (a) Study of Economic Load Dispatch by Various Hybrid Optimization Techniques, (b) An Application of Color Magnetic Resonance Brain Image Segmentation by ParaOptiMUSIG activation Function, (c) Hybrid Rough-PSO Approach in Remote Sensing Imagery Analysis,  (d) A Study and Analysis of Hybrid Intelligent Techniques for Breast Cancer Detection using Breast Thermograms, and (e) Hybridization of 2D-3D Images for Human Face Recognition. The elaborate findings of the chapters enhance the exhibition of the hybrid soft computing paradigm in the field of intelligent computing.

  3. SCAN-based hybrid and double-hybrid density functionals from parameter-free models

    CERN Document Server

    Hui, Kerwin

    2015-01-01

    By incorporating the nonempirical SCAN semilocal density functional [Sun, Ruzsinszky, and Perdew, Phys. Rev. Lett. 115, 036402 (2015)] in the underlying expression, we propose one hybrid (SCAN0) and three double-hybrid (SCAN0-DH, SCAN-QIDH, and SCAN0-2) density functionals, which are free of any empirical parameter. The SCAN-based hybrid and double-hybrid functionals consistently outperform their parent SCAN semilocal functional for a wide range of applications. The SCAN-based semilocal, hybrid, and double-hybrid functionals generally perform better than the corresponding PBE-based functionals. In addition, the SCAN0-2 and SCAN-QIDH double-hybrid functionals significantly reduce the qualitative failures of the SCAN semilocal functional, such as the self-interaction error and noncovalent interaction error, extending the applicability of the SCAN-based functionals to a very diverse range of systems.

  4. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  5. Continuity Controlled Hybrid Automata

    OpenAIRE

    Bergstra, J. A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of hybrid automata as timed transition systems. We also relate the synchronized product operator on hybrid automata to the parallel composition operator of the process algebra. It turns out that the f...

  6. The Mediating Effects of Work-Related Stress on Mentoring Functions and Job Attitude: A Comparison of General and Special Education Teachers

    Science.gov (United States)

    Rabenhorst, Greg A.

    2011-01-01

    The current study is designed to investigate the mediating effects of work-related stress on the relationship between mentoring functions (i.e., career support, psychosocial support, and role modeling) and measures of job attitude (i.e., job satisfaction and organizational commitment). Mentoring is widely used as a means of assisting in the new…

  7. Concurrent and prospective associations of habitual overgeneral memory and prospection with symptoms of depression, general anxiety, obsessive compulsiveness, and post-traumatic stress

    NARCIS (Netherlands)

    Boelen, Paul A.; Huntjens, Rafaele J. C.; van den Hout, Marcel A.

    2014-01-01

    Reduced memory specificity is associated with depression, post-traumatic stress disorder (PTSD), and some other forms of psychopathology. Reduced memory specificity is also associated with reduced specificity of envisioned future events. Research in this area has mostly relied on cue-word methods th

  8. The Mediating Effects of Work-Related Stress on Mentoring Functions and Job Attitude: A Comparison of General and Special Education Teachers

    Science.gov (United States)

    Rabenhorst, Greg A.

    2011-01-01

    The current study is designed to investigate the mediating effects of work-related stress on the relationship between mentoring functions (i.e., career support, psychosocial support, and role modeling) and measures of job attitude (i.e., job satisfaction and organizational commitment). Mentoring is widely used as a means of assisting in the new…

  9. An Improved Hybrid Method for Inverse Obstacle Scattering Problems

    Institute of Scientific and Technical Information of China (English)

    LIU JUAN; MA FU-MING

    2011-01-01

    An improved hybrid method is introduced in this paper as a numerical method to reconstruct the scatterer by far-field pattern for just one incident direction with unknown physical properties of the scatterer.The improved hybrid method inherits the idea of the hybrid method by Kress and Serranho which is a combination of Newton and decomposition method,and it improves the hybrid method by introducing a general boundary condition.The numerical experiments show the feasibility of this method.

  10. Hybridized tetraquarks

    Directory of Open Access Journals (Sweden)

    A. Esposito

    2016-07-01

    Full Text Available We propose a new interpretation of the neutral and charged X,Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z particles. Considerations on a state with the same quantum numbers as the X(5568 are also made.

  11. Hybridized Tetraquarks

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero binding energy whose counterpart in h-tetraquarks is a positive quantity. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs pi+- channel by the D0 collaboration and the negative result presented subsequently by the LHCb collaboration are understood in this scheme, together with a considerable portion of available data on X, Z particles. Considerations on a state with the same quantum numbers as the X(5568) are also made.

  12. 基于广义马氏距离的混合型多属性决策的TOPSIS方法%TOPSIS Method for Hybrid Multiple-Attribute Decision Making Based on Generalized Mahalanobis Distance

    Institute of Scientific and Technical Information of China (English)

    张峰; 谢振华; 程江涛; 林健; 徐衡博

    2013-01-01

    In order to solve the hybrid multiple-attribute decision making problem, different attribute values were unified into interval number. In the TOPSIS based on Mahalanobis distance, because of the strong linear correlation indexes, the covariance matrix was singular, and calculating the Mahalanobis distance didn’t work . Therefore , covariance matrix of in-terval number was defined and singular value decomposition method was adopted to calculate generalized inverse matrix of covariance matrix. The improved algorithm overcame the defects in the traditional TOPSIS model of river health assess-ment, such as correlations between indices, uncertainty in estimating the weights subjectively, difficulty in determining the membership function and possibility of the scheme closed to ideal solution and negative-ideal solution concurrently. In the end, a numerical example illustrated the validity and applicability of the proposed method.%为了解决混合型多属性决策问题,将不同属性值转换为区间数形式。在基于马氏距离的逼近理想解排序法(TOPSIS)中,指标间线性强相关导致协方差矩阵为奇异矩阵,不能计算马氏距离。因此,定义了区间数的协方差矩阵,采用奇异值分解方法计算协方差矩阵的广义(M-P)逆矩阵。改进的算法克服了传统TOPSIS存在的指标信息重复、主观赋权不合理、隶属度难以确定,以及可能出现与理想解欧式距离近的方案与负理想解的欧式距离也近的不足。最后,给出了该方法的一个算例,结果表明该决策方法是实用和可行的。

  13. Effect of general nursing intervention on psychological stress factors in patients with infectious disease%综合护理干预对传染病患者心理应激因素的影响

    Institute of Scientific and Technical Information of China (English)

    黄哲梅; 黄顺坤; 李剑妮; 彭秋燕; 洪婉媚

    2012-01-01

    Objective To explore the effect of general nursing intervention on psychological stress factors in patients with infectious disease. Methods 320 inpatients with infectious disease involved in the investigation of psychological stress factors with a self-designed questionnaire from October 2010 to June 2011. The general nursing intervention was carried out according to psychological stress factors of patients. The changes of psychological stress factors were compared before and after the intervention. Results Several psychological stress factors were analyzed such as fear and anxiety about illness, fearing of infecting family members, fearing of being estranged after people know about their illness, worrying about changes of their living environment, worrying about medical technology and service attitude, worrying about being infected with other diseases, worrying about being restricted on social intercourse. After nursing intervention, the majority of psychological stress was relieved. There was significant difference between pre-intervention and post-intervention (P < 0.05). Conclusion Psychological stress in hospitalized patients with infectious diseases can be relieved by targeted nursing psychological intervention.%目的 探讨综合护理干预对传染病患者心理应激因素的影响.方法 2010年10月~2011年6月自行设计调查问卷,对320例传染病住院患者心理应激因素进行调查,根据患者心理应激因素进行护理干预.比较干预前后患者心理应激因素改善情况.结果 护理干预后,患者对所患疾病恐惧与焦虑、担心疾病传染给自己家人、担心被别人知道自己患传染病而被疏远、为所处的环境改变感到担忧、担心医护人员的技术水平和服务态度、住院期间担心被传染其他疾病、活动范围受限制等方面,干预前后比较,差异具有统计学意义(均P< 0.05),干预后患者心理应激因素明显改善.结论 有针对性的综合护理干

  14. The influence of maternal vulnerability and parenting stress on chronic pain in adolescents in a general population sample : The TRAILS study

    NARCIS (Netherlands)

    Darlington, A-S. E.; Verhulst, F. C.; De Winter, A. F.; Ormel, J.; Passchier, J.; Hunfeld, J. A. M.

    2012-01-01

    Investigating possible psychosocial predictors of unexplained chronic pain in adolescents is crucial in understanding its development and prevention. A general population sample of adolescents (n = 2230) from the TRAILS cohort study was investigated longitudinally to assess the influence of maternal

  15. Additive Manufacturing of Hybrid Circuits

    Science.gov (United States)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  16. Continuity Controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  17. Continuity controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2008-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  18. Interaction of the heterotrimeric G protein alpha subunit SSG-1 of Sporothrix schenckii with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay

    Directory of Open Access Journals (Sweden)

    González-Méndez Ricardo

    2010-12-01

    Full Text Available Abstract Background Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins. Results Using the yeast two-hybrid technique, we identified protein-protein interactions between SSG-1 and other important cellular proteins. The interactions were corroborated using co-immuneprecipitation. Using these techniques we identified a Fe/Mn superoxide dismutase (SOD, a glyceraldehyde-3-P dehydrogenase (GAPDH and two ion transport proteins, a siderophore-iron transporter belonging to the Major Facilitator Superfamily (MFS and a divalent-cation transporter of the Nramp (natural resistance-associated macrophage protein family as interacting with SSG-1. The cDNA's encoding these proteins were sequenced and bioinformatic macromolecular sequence analyses were used for the correct classification and functional assignment. Conclusions This study constitutes the first report of the interaction of a fungal G alpha inhibitory subunit with SOD, GAPDH, and two metal ion transporters. The identification of such important proteins as partners of a G alpha subunit in this fungus suggests possible mechanisms through which this G protein can affect pathogenicity and survival under conditions of environmental stress or inside the human host. The two ion transporters identified in this work are the first to be reported in S. schenckii and the first time they are identified as interacting with fungal G protein alpha subunits. The association

  19. Comparative evaluation of oral gabapentin versus clonidine as premedication on preoperative sedation and laryngoscopic stress response attenuation for the patients undergoing general anesthesia

    Directory of Open Access Journals (Sweden)

    Saikat Majumdar

    2015-01-01

    Results and Analysis: Preoperative sedation between two groups were similar but group C attenuated HR, systolic blood pressure (SBP, diastolic blood pressure (DBP, and mean blood pressure (MBP more significantly before induction, during L and I, 1, 3, and 5 min, following L and I, while comparing with group G. Again gabapentin-reduced HR, BP, (SBP, DBP, MBP significantly more at 7 and 10 min after L and I on comparison clonidine. Conclusion: Oral clonidine is equally effective in producing preoperative sedation in comparison to oral gabapentin, while on the contrary oral clonidine is more efficacious in reducing laryngoscopic stress response than oral gabapentin.

  20. Genomic Prediction of Barley Hybrid Performance

    Directory of Open Access Journals (Sweden)

    Norman Philipp

    2016-07-01

    Full Text Available Hybrid breeding in barley ( L. offers great opportunities to accelerate the rate of genetic improvement and to boost yield stability. A crucial requirement consists of the efficient selection of superior hybrid combinations. We used comprehensive phenotypic and genomic data from a commercial breeding program with the goal of examining the potential to predict the hybrid performances. The phenotypic data were comprised of replicated grain yield trials for 385 two-way and 408 three-way hybrids evaluated in up to 47 environments. The parental lines were genotyped using a 3k single nucleotide polymorphism (SNP array based on an Illumina Infinium assay. We implemented ridge regression best linear unbiased prediction modeling for additive and dominance effects and evaluated the prediction ability using five-fold cross validations. The prediction ability of hybrid performances based on general combining ability (GCA effects was moderate, amounting to 0.56 and 0.48 for two- and three-way hybrids, respectively. The potential of GCA-based hybrid prediction requires that both parental components have been evaluated in a hybrid background. This is not necessary for genomic prediction for which we also observed moderate cross-validated prediction abilities of 0.51 and 0.58 for two- and three-way hybrids, respectively. This exemplifies the potential of genomic prediction in hybrid barley. Interestingly, prediction ability using the two-way hybrids as training population and the three-way hybrids as test population or vice versa was low, presumably, because of the different genetic makeup of the parental source populations. Consequently, further research is needed to optimize genomic prediction approaches combining different source populations in barley.

  1. Endophytic colonization of barley (Hordeum vulgare) roots by the nematophagous fungus Pochonia chlamydosporia reveals plant growth promotion and a general defense and stress transcriptomic response.

    Science.gov (United States)

    Larriba, Eduardo; Jaime, María D L A; Nislow, Corey; Martín-Nieto, José; Lopez-Llorca, Luis Vicente

    2015-07-01

    Plant crop yields are negatively conditioned by a large set of biotic and abiotic factors. An alternative to mitigate these adverse effects is the use of fungal biological control agents and endophytes. The egg-parasitic fungus Pochonia chlamydosporia has been traditionally studied because of its potential as a biological control agent of plant-parasitic nematodes. This fungus can also act as an endophyte in monocot and dicot plants, and has been shown to promote plant growth in different agronomic crops. An Affymetrix 22K Barley GeneChip was used in this work to analyze the barley root transcriptomic response to P. chlamydosporia root colonization. Functional gene ontology (GO) and gene set enrichment analyses showed that genes involved in stress response were enriched in the barley transcriptome under endophytism. An 87.5% of the probesets identified within the abiotic stress response group encoded heat shock proteins. Additionally, we found in our transcriptomic analysis an up-regulation of genes implicated in the biosynthesis of plant hormones, such as auxin, ethylene and jasmonic acid. Along with these, we detected induction of brassinosteroid insensitive 1-associated receptor kinase 1 (BR1) and other genes related to effector-triggered immunity (ETI) and pattern-triggered immunity (PTI). Our study supports at the molecular level the growth-promoting effect observed in plants endophytically colonized by P. chlamydosporia, which opens the door to further studies addressing the capacity of this fungus to mitigate the negative effects of biotic and abiotic factors on plant crops.

  2. Double-hybrid density-functional theory made rigorous

    CERN Document Server

    Sharkas, Kamal; Savin, Andreas

    2010-01-01

    We provide a rigorous derivation of a class of double-hybrid approximations, combining Hartree-Fock exchange and second-order Moller-Plesset correlation with a semilocal exchange-correlation density functional. These double-hybrid approximations contain only one empirical parameter and use a density-scaled correlation energy functional. Neglecting density scaling leads to an one-parameter version of the standard double-hybrid approximations. We assess the performance of these double-hybrid schemes on representative test sets of atomization energies and reaction barrier heights, and we compare to other hybrid approximations, including range-separated hybrids. Our best one-parameter double-hybrid approximation, called 1DH-BLYP, roughly reproduces the two parameters of the standard B2-PLYP or B2GP-PLYP double-hybrid approximations, which shows that these methods are not only empirically close to an optimum for general chemical applications but are also theoretically supported.

  3. Stress Management: Job Stress

    Science.gov (United States)

    Healthy Lifestyle Stress management Job stress can be all-consuming — but it doesn't have to be. Address your triggers, keep perspective and ... stress triggers, it's often helpful to improve time management skills — especially if you tend to feel overwhelmed ...

  4. Biaxial stress effects on magnetization perpendicular to the stress plane

    Energy Technology Data Exchange (ETDEWEB)

    Sablik, M.J.; Kwun, H.; Burkhardt, G.L. [Southwest Research Inst., San Antonio, TX (United States); Langman, R.A. [Univ. of Tasmania, Hobart, Tasmania (Australia)

    1995-11-01

    Effects of biaxial stress in steel on magnetization in a direction normal to the stress plane were investigated both theoretically and experimentally. The two results, which agreed qualitatively, showed that the magnetization in the normal direction generally decreased with the absolute value of the sum of the two principal stresses. The implication to nondestructive measurements of biaxial stress is discussed.

  5. Organic/inorganic hybrid coatings for anticorrosion

    Science.gov (United States)

    He, Zhouying

    Compared to organic coatings, organic-inorganic hybrid coatings can potentially improve the anticorrosion performance. The organic phase provides the excellent mechaincal and barrier properties while the inorganic phase acts as an adhesion promoter and corrosion inhibitor. Despite that many studies on alkoxylsilane-based hybrid coatings have been developed and studied, their weatherability and anticorrosion performance has been rarely evaluated. On the other hand, organic-inorganic hybrid coatings based on mixed sol-gel precursors have received much less attention compared to alkoxylsilane-based hybrid coatings. In the first part, polyurethane hybrid coatings with a unique hybrid crosslinked structure as an improved unicoat were successfully prepared. The effect of polyesters on physical properties of the hybrid coatings was studied. Polyurethane coatings derived from cycloaliphatic polyester show comparable properties than those derived from the commercially viable aromatic polyester. Introducing the polysiloxane part into the polyurethane coatings enhanced the crosslinking density, Tg, mechanical properties, and general coating properties. The increased adhesion between the hybrid coating and the substrate make the hybrid coating a good candidate for anticorrosion application, which is shown by electrochemical impedance spectroscopy (EIS). The degradation mechanism of the polyurethane/polysiloxane hybrid coatings under various weathering conditions was shown to be the scission of the urethane and ester groups in the organic phase along with reorganizing and rearranging of the inorganic phase. The anticorrosion performance of the cycloaliphatic hybrid was much better than that of aromatic based hybrid under outdoor weathering based on visual observation and EIS analysis. Acid undercutting is an issue for TEOS based hybrid coating. In the second part, design of experiments (DOEs) was used to statistically investigate on the effect of sol-gel precursors. The

  6. Novel brewing yeast hybrids: creation and application.

    Science.gov (United States)

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2017-01-01

    The natural interspecies Saccharomyces cerevisiae × Saccharomyces eubayanus hybrid yeast is responsible for global lager beer production and is one of the most important industrial microorganisms. Its success in the lager brewing environment is due to a combination of traits not commonly found in pure yeast species, principally low-temperature tolerance, and maltotriose utilization. Parental transgression is typical of hybrid organisms and has been exploited previously for, e.g., the production of wine yeast with beneficial properties. The parental strain S. eubayanus has only been discovered recently and newly created lager yeast strains have not yet been applied industrially. A number of reports attest to the feasibility of this approach and artificially created hybrids are likely to have a significant impact on the future of lager brewing. De novo S. cerevisiae × S. eubayanus hybrids outperform their parent strains in a number of respects, including, but not restricted to, fermentation rate, sugar utilization, stress tolerance, and aroma formation. Hybrid genome function and stability, as well as different techniques for generating hybrids and their relative merits are discussed. Hybridization not only offers the possibility of generating novel non-GM brewing yeast strains with unique properties, but is expected to aid in unraveling the complex evolutionary history of industrial lager yeast.

  7. Childhood Stress

    Science.gov (United States)

    ... Kids to Be Smart About Social Media Childhood Stress KidsHealth > For Parents > Childhood Stress Print A A ... and feel stress to some degree. Sources of Stress Stress is a function of the demands placed ...

  8. Nonlinear/linear unified thermal stress formulations - Transfinite element approach

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    A new unified computational approach for applicability to nonlinear/linear thermal-structural problems is presented. Basic concepts of the approach including applicability to nonlinear and linear thermal structural mechanics are first described via general formulations. Therein, the approach is demonstrated for thermal stress and thermal-structural dynamic applications. The proposed transfinite element approach focuses on providing a viable hybrid computational methodology by combining the modeling versatility of contemporary finite element schemes in conjunction with transform techniques and the classical Bubnov-Galerkin schemes. Comparative samples of numerical test cases highlight the capabilities of the proposed concepts.

  9. A DG Implementation of a Novel Hybrid RANS/LES Technique With RANS Reconstruction

    CERN Document Server

    Abbà, Antonella; Nini, Michele; Restelli, Marco

    2014-01-01

    A new hybrid RANS/LES technique, based on the hybrid filter proposed by Germano in 2004, has been studied. The novelty herein introduced is represented by the reconstruction of the Reynolds stress tensor. As a consequence, no explicit RANS model is needed. The RANS and LES terms are merged using a constant blending factor. The model is implemented in a numerical code based on a high order Discontinuous Galerkin (DG) finite element formulation. The test case considered for numerical simulations is the turbulent tur- bulent channel flow at Mach = 0.2. The comparison with available DNS data shows a good agreement and, in general, an improvement with re- spect to pure LES results, confirming that the technique herein proposed represents a promising approach to the numerical simulation of turbulent flows.

  10. Hybrid turbulence models for atmospheric flow: A proper comparison with RANS models

    Directory of Open Access Journals (Sweden)

    Bautista Mary C.

    2015-01-01

    Full Text Available A compromise between the required accuracy and the need for affordable simulations for the wind industry might be achieved with the use of hybrid turbulence models. Detached-Eddy Simulation (DES [1] is a hybrid technique that yields accurate results only if it is used according to its original formulation [2]. Due to its particular characteristics (i.e., the type of mesh required, the modeling of the atmospheric flow might always fall outside the original scope of DES. An enhanced version of DES called Simplify Improved Delayed Detached-Eddy Simulation (SIDDES [3] can overcome this and other disadvantages of DES. In this work the neutrally stratified atmospheric flow over a flat terrain with homogeneous roughness will be analyzed using a Reynolds-Averaged Navier–Stokes (RANS model called k – ω SST (shear stress transport [4], and the hybrids k – ω SST-DES and k – ω SST-SIDDES models. An obvious test is to validate these hybrid approaches and asses their advantages and disadvantages over the pure RANS model. However, for several reasons the technique to drive the atmospheric flow is generally different for RANS and LES or hybrid models. The flow in a RANS simulation is usually driven by a constant shear stress imposed at the top boundary [5], therefore modeling only the atmospheric surface layer. On the contrary the LES and hybrid simulations are usually driven by a constant pressure gradient, thus a whole atmospheric boundary layer is simulated. Rigorously, this represents two different simulated cases making the model comparison not trivial. Nevertheless, both atmospheric flow cases are studied with the mentioned models. The results prove that a simple comparison of the time average turbulent quantities obtained by RANS and hybrid simulations is not easily achieved. The RANS simulations yield consistent results for the atmospheric surface layer case, while the hybrid model results are not correct. As for the atmospheric boundary

  11. Comparative evaluation of oral gabapentin versus clonidine as premedication on preoperative sedation and laryngoscopic stress response attenuation for the patients undergoing general anesthesia

    OpenAIRE

    Saikat Majumdar; Anjan Das; Haripada Das; Sambhunath Bandyopadhyay; Bimal Kumar Hajra; Dipankar Mukherjee

    2015-01-01

    Background: Laryngoscopy and endotracheal intubation (L and I) is associated with rise in blood pressure (BP), heart rate (HR), leading to adverse cardiological outcome especially in susceptible individuals. To compare the BP, HR during L and I as well as to evaluate the preoperative sedation status between oral clonidine (Group C) and oral gabapentine (Group G) as premedication for the patients undergoing major surgery under general anesthesia (GA). Materials and Methods: From April 2008...

  12. Comparative evaluation of oral clonidine and midazolam as premedication on preoperative sedation and laryngoscopic stress response attenuation for the patients undergoing general anaesthesia

    OpenAIRE

    Anjan Das; Tushar Kanti Saha; Saikat Majumdar; Rahul Deb Mandal; Anindya Mukherjee; Subrata Kumar Mandal

    2013-01-01

    Context: Laryngoscopy and endotracheal intubation is associated detrimental hemodynamic changes like rise in blood pressure (BP), heart rate (HR) leading to adverse cardiological outcome specially in susceptible individuals. Aims: To compare the blood pressure (BP) and heart rate (HR) changes during laryngoscopy and endotracheal intubation as well as to evaluate the preoperative sedation status between oral clonidine and oral midazolam as premedication for the patients undergoing general anes...

  13. [Stress in surgeries].

    Science.gov (United States)

    Daian, Márcia Rodrigues; Petroianu, Andy; Alberti, Luiz Ronaldo; Jeunon, Ester Eliane

    2012-01-01

    The purpose of this article was to provide the literature regarding the psychological stress in the peri-operative period of adult patients undergoing operations under general anesthesia. The articles were obtained by surveying the papers published and catalogued in the Medline Pubmed interface database, Lilacs and the Biblioteca Virtual de Saúde (BVS) since 1984, crossing the headings stress, surgery, general anesthesia, psychology. Over 800 articles related to stress and surgery were analyzed with regards to their relevance to the considered subject. Eighteen articles were related to psychological stress. Their results confirmed the presence of psychological and physical stress, during the peri-operative period as well as relation between stress and de clinical post-operative recovery. There is a gap regarding in the peri-operative period. More studies on psychological influence on stress may benefit patients and help professionals during the surgical treatment.

  14. Fotossíntese, remobilização de reservas e crescimento de grãos em dois híbridos de milho sob deficiência hídrica na fase de enchimento dos grãos Photosynthesis, reserves remobilization and grain growth of two maize hybrids submitted to water stress during the grain filling stage

    Directory of Open Access Journals (Sweden)

    Eduardo Caruso Machado

    1992-01-01

    Full Text Available Foram avaliados, em dois híbridos simples de milho (Zea mays L., Pioneer 3072 e IAC 701 x B, submetidos à deficiência hídrica, o comportamento da fotossíntese, da remobilização de N e de açúcares durante o período de crescimento dos grãos. As plantas foram cultivadas sob condições naturais, em doze tanques de alvenaria (4 m de comprimento x 0,5 m de largura x 0,6 m de profundidade contendo terra. A deficiência hídrica foi induzida entre o 5.º e o 15.º dia após a floração, suspendendo-se a irrigação. Sem deficiência hídrica, ambos os híbridos apresentaram comportamento semelhante quanto aos parâmetros avaliados. Sob deficiência hídrica, a remobilização de açúcares e de N, a partir dos órgãos vegetativos para os grãos, foi mais intensa que nas plantas-controle, sem deficiência hídrica, e mais acentuada, tanto em açúcares como em N, no híbrido IAC 701 x B. Sob deficiência hídrica, a taxa de fotossíntese diminuiu em ambos os híbridos, sobretudo no IAC 701 x B.Photosynthesis, nitrogen and sugar remobilization during the grain filling period were examined in two maize (Zea mays L. hybrids (Pioneer 3072 and IAC 701 x B submitted to water stress. The plants were grown under natural conditions in 12 boxes (4 m x 0,5 m x 0.6 m each containing soil. Water stress was imposed by with holding irrigation during the 5.th and 15.th days after anthesis. Both hybrids in control treatment (without water stress showed no differences in relation to the avaliated parameters. Under water stress the sugar and N remobilization from vegetative organs to the grains, were more intense than of the control plants. The sugar and N remobilization were larger in IAC 701 x B. The photosynthesis rates were reduced in both hybrids under water stress, but the reduction was larger in IAC 701 x B.

  15. Hybrid reactors: Nuclear breeding or energy production?

    Energy Technology Data Exchange (ETDEWEB)

    Piera, Mireia [UNED, ETSII-Dp Ingenieria Energetica, c/Juan del Rosal 12, 28040 Madrid (Spain); Lafuente, Antonio; Abanades, Alberto; Martinez-Val, J.M. [ETSII-UPM, c/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2010-09-15

    After reviewing the long-standing tradition on hybrid research, an assessment model is presented in order to characterize the hybrid performance under different objectives. In hybrids, neutron multiplication in the subcritical blanket plays a major role, not only for energy production and nuclear breeding, but also for tritium breeding, which is fundamental requirement in fusion-fission hybrids. All three objectives are better achieved with high values of the neutron multiplication factor (k-eff) with the obvious and fundamental limitation that it cannot reach criticality under any event, particularly, in the case of a loss of coolant accident. This limitation will be very important in the selection of the coolant. Some general considerations will be proposed, as guidelines for assessing the hybrid potential in a given scenario. Those guidelines point out that hybrids can be of great interest for the future of nuclear energy in a framework of Sustainable Development, because they can contribute to the efficient exploitation of nuclear fuels, with very high safety features. Additionally, a proposal is presented on a blanket specially suited for fusion-fission hybrids, although this reactor concept is still under review, and new work is needed for identifying the most suitable blanket composition, which can vary depending on the main objective of the hybrid. (author)

  16. Hybrid Batch Bayesian Optimization

    CERN Document Server

    Azimi, Javad; Fern, Xiaoli

    2012-01-01

    Bayesian Optimization aims at optimizing an unknown non-convex/concave function that is costly to evaluate. We are interested in application scenarios where concurrent function evaluations are possible. Under such a setting, BO could choose to either sequentially evaluate the function, one input at a time and wait for the output of the function before making the next selection, or evaluate the function at a batch of multiple inputs at once. These two different settings are commonly referred to as the sequential and batch settings of Bayesian Optimization. In general, the sequential setting leads to better optimization performance as each function evaluation is selected with more information, whereas the batch setting has an advantage in terms of the total experimental time (the number of iterations). In this work, our goal is to combine the strength of both settings. Specifically, we systematically analyze Bayesian optimization using Gaussian process as the posterior estimator and provide a hybrid algorithm t...

  17. Hadron rapidity spectra within a hybrid model

    CERN Document Server

    Khvorostukhin, A S

    2016-01-01

    A 2-stage hybrid model is proposed that joins the fast initial state of interaction, described by the hadron string dynamics (HSD) model, to subsequent evolution of the expanding system at the second stage, treated within ideal hydrodynamics. The developed hybrid model is assigned to describe heavy-ion collisions in the energy range of the NICA collider under construction in Dubna. Generally, the model is in reasonable agreement with the available data on proton rapidity spectra. However, reproducing proton rapidity spectra, our hybrid model cannot describe the rapidity distributions of pions. The model should be improved by taking into consideration viscosity effects at the hydrodynamical stage of system evolution.

  18. Concurrent and prospective associations of habitual overgeneral memory and prospection with symptoms of depression, general anxiety, obsessive compulsiveness, and post-traumatic stress.

    Science.gov (United States)

    Boelen, Paul A; Huntjens, Rafaele J C; van den Hout, Marcel A

    2014-01-01

    Reduced memory specificity is associated with depression, post-traumatic stress disorder (PTSD), and some other forms of psychopathology. Reduced memory specificity is also associated with reduced specificity of envisioned future events. Research in this area has mostly relied on cue-word methods that include explicit instructions to develop specific memories of future events. These methods are limited in their ability to assess how participants habitually remember the past and imagine the future when the specificity constraints inherent in the cue-word task are removed. Sentence completions tasks have been developed that can be used to assess habitual patterns of memory and prospection. Little is known about the association of habitual memory and prospection with concurrently and prospectively assessed psychopathology. In the current study 142 participants completed sentence completion tasks tapping habitual memory and prospection at baseline and completed measures tapping psychological symptoms at baseline and 1 year later. Among other things, it was found that reduced memory specificity (but not reduced future specificity) was associated with concurrent and later depression, as well as with symptom levels of PTSD tapped 1 year beyond baseline.

  19. Major benzophenone concentrations and influence of food consumption among the general population in Korea, and the association with oxidative stress biomarker.

    Science.gov (United States)

    Kim, Bokyung; Kwon, Bareum; Jang, Sol; Kim, Pan-Gyi; Ji, Kyunghee

    2016-09-15

    Benzophenones (BPs) have been used as sunscreen agents and as ultraviolet stabilizers in plastic surface coatings for food packaging. However, few studies have been performed to examine the level of human exposure to BPs and the potential sources of such exposure. We evaluated the exposure levels to six major BPs (BP-1, BP-2, BP-3, BP-4, BP-8, and 4-hydroxybenzophenone (4-OH-BP)) among the adult population in two cities in Korea, and investigated the potential dietary sources of the BPs. Urinary levels of malondialdehyde (MDA) as an oxidative stress biomarker as well as their association with the levels of BPs were also analyzed. Among the six BPs analyzed, 4-OH-BP, BP-1, BP-3, and BP-4 were detected in 77%, 49%, 27%, and 21% of the population, respectively. BP concentrations were relatively higher in younger (people in their 20s and 30s) cosmetic users and leaner women. Even after the adjustment of age, body mass index, and cosmetic use, the consumption of frozen storage food, instant noodles, and instant coffee was significantly correlated with urinary BPs, and these associations were sex-dependent. No significant correlation was observed between the levels of BPs and levels of MDA. The results of the present study will be useful for developing plans of public health management of BPs. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Generalized fiber Fourier optics.

    Science.gov (United States)

    Cincotti, Gabriella

    2011-06-15

    A twofold generalization of the optical schemes that perform the discrete Fourier transform (DFT) is given: new passive planar architectures are presented where the 2 × 2 3 dB couplers are replaced by M × M hybrids, reducing the number of required connections and phase shifters. Furthermore, the planar implementation of the discrete fractional Fourier transform (DFrFT) is also described, with a waveguide grating router (WGR) configuration and a properly modified slab coupler.

  1. Functional stability of endothelial cells on a novel hybrid scaffold for vascular tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Pankajakshan, Divya; Krishnan, Lissy K [Thrombosis Research Unit, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojapura, Trivandrum 695 012 (India); Krishnan V, Kalliyana, E-mail: lissykk@sctimst.ac.i [Division of Polymer Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojapura, Trivandrum 695 012 (India)

    2010-12-15

    Porous and pliable conduits made of biodegradable polymeric scaffolds offer great potential for the development of blood vessel substitutes but they generally lack signals for cell proliferation, survival and maintenance of a normal phenotype. In this study we have prepared and evaluated porous poly({epsilon}-caprolactone) (PCL) integrated with fibrin composite (FC) to get a biomimetic hybrid scaffold (FC PCL) with the biological properties of fibrin, fibronectin (FN), gelatin, growth factors and glycosaminoglycans. Reduced platelet adhesion on a human umbilical vein endothelial cell-seeded hybrid scaffold as compared to bare PCL or FC PCL was observed, which suggests the non-thrombogenic nature of the tissue-engineered scaffold. Analysis of real-time polymerase chain reaction (RT-PCR) after 5 days of endothelial cell (EC) culture on a hybrid scaffold indicated that the prothrombotic von Willebrand factor and plasminogen activator inhibitor (PAI) were quiescent and stable. Meanwhile, dynamic expressions of tissue plasminogen activator (tPA) and endothelial nitric oxide synthase indicated the desired cell phenotype on the scaffold. On the hybrid scaffold, shear stress could induce enhanced nitric oxide release, which implicates vaso-responsiveness of EC grown on the tissue-engineered construct. Significant upregulation of mRNA for extracellular matrix (ECM) proteins, collagen IV and elastin, in EC was detected by RT-PCR after growing them on the hybrid scaffold and FC-coated tissue culture polystyrene (FC TCPS) but not on FN-coated TCPS. The results indicate that the FC PCL hybrid scaffold can accomplish a remodeled ECM and non-thrombogenic EC phenotype, and can be further investigated as a scaffold for cardiovascular tissue engineering. (communication)

  2. From hybrid swarms to swarms of hybrids

    Science.gov (United States)

    The introgression of modern humans (Homo sapiens) with Neanderthals 40,000 YBP after a half-million years of separation, may have led to the best example of a hybrid swarm on earth. Modern trade and transportation in support of the human hybrids has continued to introduce additional species, genotyp...

  3. The Hybrid Museum: Hybrid Economies of Meaning

    DEFF Research Database (Denmark)

    Vestergaard, Vitus

    2013-01-01

    this article shows that there are two different museum mindsets where the second mindset leans towards participatory practices. It is shown how a museum can support a hybrid economy of meaning that builds on both a user generated economy of meaning and an institutional economy of meaning and adds value to both....... Such a museum is referred to as a hybrid museum....

  4. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  5. Hybrid Management in Hospitals

    DEFF Research Database (Denmark)

    Byrkjeflot, Haldor; Jespersen, Peter Kragh

    2010-01-01

    Artiklen indeholder et litteraturbaseret studium af ledelsesformer i sygehuse, hvor sundhedsfaglig ledelse og generel ledelse mikses til hybride ledelsesformer......Artiklen indeholder et litteraturbaseret studium af ledelsesformer i sygehuse, hvor sundhedsfaglig ledelse og generel ledelse mikses til hybride ledelsesformer...

  6. Marine genetic swamping: hybrids replace an obligately estuarine fish.

    Science.gov (United States)

    Roberts, David G; Gray, Charles A; West, Ronald J; Ayre, David J

    2010-02-01

    Populations of obligately estuarine taxa are potentially small and isolated and may lack genetic variation and display regional differentiation as a result of drift and inbreeding. Hybridization with a wide-ranging marine congener should introduce genetic variation and reduce the effects of inbreeding depression and genetic drift. However, high levels of hybridization can cause demographic and genetic swamping. In southeastern Australia hybridization occurs between obligately estuarine Black bream (Acanthopagrus butcheri) and migratory marine Yellowfin bream (Acanthopagrus australis). Here, we surveyed genetic variation at eight microsatellite loci and the mitochondrial control region of juvenile fish from five coastal lagoons (including temporal replication in two lagoons) (total n = 970) to determine the frequency and persistence of hybridization, and its likely consequence for the estuarine restricted A. butcheri. Of 688 juvenile fish genotyped 95% were either A. australis (347) or hybrids (309); only 5% (32) were A. butcheri. Most hybrids were later generation hybrids or A. butcheri backcrosses, which are likely multi-generational residents within lagoons. Far greater proportions of hybrid juveniles were found within two lagoons that are generally closed to the ocean (>90% hybrid fish within generally closed lagoons vs. 12-27% in permanently or intermittently open lagoons). In both lagoons, this was consistent across multiple cohorts of fish [79-97% hybrid fish (n = 282)]. Hybridization and introgression represent a major threat to the persistence of A. butcheri and have yet to be investigated for large numbers of estuarine taxa.

  7. A Generalized Yield Criterion

    Institute of Scientific and Technical Information of China (English)

    Shijian YUAN; Dazhi XIAO; Zhubin HE

    2004-01-01

    A generalized yield criterion is proposed based on the metal plastic deformation mechanics and the fundamental formula in theory of plasticity. Using the generalized yield criterion, the reason is explained that Mises yield criterion and Tresca yield criterion do not completely match with experimental data. It has been shown that the yield criteria of ductile metals depend not only on the quadratic invariant of the deviatoric stress tensor J2, but also on the cubic invariant of the deviatoric stress tensor J3 and the ratio of the yield stress in pure shear to the yield stress in uniaxial tension k/σs. The reason that Mises yield criterion and Tresca yield criterion are not in good agreement with the experimental data is that the effect of J3 and k/σs is neglected.

  8. Resin Catalyst Hybrids

    Institute of Scientific and Technical Information of China (English)

    S. Asaoka

    2005-01-01

    @@ 1Introduction: What are resin catalyst hybrids? There are typically two types of resin catalyst. One is acidic resin which representative is polystyrene sulfonic acid. The other is basic resin which is availed as metal complex support. The objective items of this study on resin catalyst are consisting of pellet hybrid, equilibrium hybrid and function hybrid of acid and base,as shown in Fig. 1[1-5].

  9. Mesoscale hybrid calibration artifact

    Science.gov (United States)

    Tran, Hy D.; Claudet, Andre A.; Oliver, Andrew D.

    2010-09-07

    A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

  10. Euro hybrid materials and structures. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, Joachim M.; Siebert, Marc (eds.)

    2016-08-01

    In order to use the materials as best as possible, several different materials are usually mixed in one component, especially in the field of lightweight design. If these combinations of materials are joined inherently, they are called multi material design products or hybrid structures. These place special requirements on joining technology, design methods and manufacturing and are challenging in other aspects, too. The eight chapters with manuscripts of the presentations are: Chapter 1- Interface: What happens in the interface between the two materials? Chapter 2 - Corrosion and Residual Stresses: How about galvanic corrosion and thermal residual stresses in the contact zone of different materials? Chapter 3 - Characterization: How to characterize and test hybrid materials? Chapter 4 - Design: What is a suitable design and dimensioning method for hybrid structures? Chapter 5 - Machining and Processing: How to machine and process hybrid structures and materials? Chapter 6 - Component Manufacturing: What is a suitable manufacturing route for hybrid structures? Chapter 7 - Non-Destructive Testing and Quality Assurance: How to assure the quality of material and structures? Chapter 8 - Joining: How to join components of different materials?.

  11. Realizing the Hybrid Library.

    Science.gov (United States)

    Pinfield, Stephen; Eaton, Jonathan; Edwards, Catherine; Russell, Rosemary; Wissenburg, Astrid; Wynne, Peter

    1998-01-01

    Outlines five projects currently funded by the United Kingdom's Electronic Libraries Program (eLib): HyLiFe (Hybrid Library of the Future), MALIBU (MAnaging the hybrid Library for the Benefit of Users), HeadLine (Hybrid Electronic Access and Delivery in the Library Networked Environment), ATHENS (authentication scheme), and BUILDER (Birmingham…

  12. Hybrid armature projectile

    Science.gov (United States)

    Hawke, Ronald S.; Asay, James R.; Hall, Clint A.; Konrad, Carl H.; Sauve, Gerald L.; Shahinpoor, Mohsen; Susoeff, Allan R.

    1993-01-01

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasama blowby.

  13. Intraply Hybrid Composite Design

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1986-01-01

    Several theoretical approaches combined in program. Intraply hybrid composites investigated theoretically and experimentally at Lewis Research Center. Theories developed during investigations and corroborated by attendant experiments used to develop computer program identified as INHYD (Intraply Hybrid Composite Design). INHYD includes several composites micromechanics theories, intraply hybrid composite theories, and integrated hygrothermomechanical theory. Equations from theories used by program as appropriate for user's specific applications.

  14. Hybrid quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, Akira [Department of Applied Physics, School of Engineering, The University of Tokyo (Japan)

    2014-12-04

    I will briefly explain the definition and advantage of hybrid quantum information processing, which is hybridization of qubit and continuous-variable technologies. The final goal would be realization of universal gate sets both for qubit and continuous-variable quantum information processing with the hybrid technologies. For that purpose, qubit teleportation with a continuousvariable teleporter is one of the most important ingredients.

  15. Transgressive Hybrids as Hopeful Monsters.

    Science.gov (United States)

    Dittrich-Reed, Dylan R; Fitzpatrick, Benjamin M

    2013-06-01

    The origin of novelty is a critical subject for evolutionary biologists. Early geneticists speculated about the sudden appearance of new species via special macromutations, epitomized by Goldschmidt's infamous "hopeful monster". Although these ideas were easily dismissed by the insights of the Modern Synthesis, a lingering fascination with the possibility of sudden, dramatic change has persisted. Recent work on hybridization and gene exchange suggests an underappreciated mechanism for the sudden appearance of evolutionary novelty that is entirely consistent with the principles of modern population genetics. Genetic recombination in hybrids can produce transgressive phenotypes, "monstrous" phenotypes beyond the range of parental populations. Transgressive phenotypes can be products of epistatic interactions or additive effects of multiple recombined loci. We compare several epistatic and additive models of transgressive segregation in hybrids and find that they are special cases of a general, classic quantitative genetic model. The Dobzhansky-Muller model predicts "hopeless" monsters, sterile and inviable transgressive phenotypes. The Bateson model predicts "hopeful" monsters with fitness greater than either parental population. The complementation model predicts both. Transgressive segregation after hybridization can rapidly produce novel phenotypes by recombining multiple loci simultaneously. Admixed populations will also produce many similar recombinant phenotypes at the same time, increasing the probability that recombinant "hopeful monsters" will establish true-breeding evolutionary lineages. Recombination is not the only (or even most common) process generating evolutionary novelty, but might be the most credible mechanism for sudden appearance of new forms.

  16. 1997 hybrid electric vehicle specifications

    Energy Technology Data Exchange (ETDEWEB)

    Sluder, S.; Larsen, R.; Duoba, M.

    1996-10-01

    The US DOE sponsors Advanced Vehicle Technology competitions to help educate the public and advance new vehicle technologies. For several years, DOE has provided financial and technical support for the American Tour de Sol. This event showcases electric and hybrid electric vehicles in a road rally across portions of the northeastern United States. The specifications contained in this technical memorandum apply to vehicles that will be entered in the 1997 American Tour de Sol. However, the specifications were prepared to be general enough for use by other teams and individuals interested in developing hybrid electric vehicles. The purpose of the specifications is to ensure that the vehicles developed do not present a safety hazard to the teams that build and drive them or to the judges, sponsors, or public who attend the competitions. The specifications are by no means the definitive sources of information on constructing hybrid electric vehicles - as electric and hybrid vehicles technologies advance, so will the standards and practices for their construction. In some cases, the new standards and practices will make portions of these specifications obsolete.

  17. Super-hybrid composites - An emerging structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Specimens of super-hybrids and advanced fiber composites were subjected to extensive tests to determine their mechanical properties, including impact and thermal fatigue. The super-hybrids were fabricated by a procedure similar to that reported by Chamis et al., (1975). Super-hybrids subjected to 1000 cycles of thermal fatigue from -100 to 300 F retained over 90% of their longitudinal flexural strength and over 75% of their transverse flexural strength; their transverse flexural strength may be as high as 8 times that of a commercially supplied boron/1100-Al composite. The thin specimen Izod longitudinal impact resistance of the super-hybrids was twice that of the boron/110-Al material. Super-hybrids subjected to transverse tensile loads exhibited nonlinear stress-strain relationships. The experimentally determined initial membrane (in-plane) and bending elastic properties of super-hybrids were predicted adequately by linear laminate analysis.

  18. Hybrid Integrated Platforms for Silicon Photonics

    Directory of Open Access Journals (Sweden)

    John E. Bowers

    2010-03-01

    Full Text Available A review of recent progress in hybrid integrated platforms for silicon photonics is presented. Integration of III-V semiconductors onto silicon-on-insulator substrates based on two different bonding techniques is compared, one comprising only inorganic materials, the other technique using an organic bonding agent. Issues such as bonding process and mechanism, bonding strength, uniformity, wafer surface requirement, and stress distribution are studied in detail. The application in silicon photonics to realize high-performance active and passive photonic devices on low-cost silicon wafers is discussed. Hybrid integration is believed to be a promising technology in a variety of applications of silicon photonics.

  19. The hydrogen hybrid option

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.R.

    1993-10-15

    The energy efficiency of various piston engine options for series hybrid automobiles are compared with conventional, battery powered electric, and proton exchange membrane (PEM) fuel cell hybrid automobiles. Gasoline, compressed natural gas (CNG), and hydrogen are considered for these hybrids. The engine and fuel comparisons are done on a basis of equal vehicle weight, drag, and rolling resistance. The relative emissions of these various fueled vehicle options are also presented. It is concluded that a highly optimized, hydrogen fueled, piston engine, series electric hybrid automobile will have efficiency comparable to a similar fuel cell hybrid automobile and will have fewer total emissions than the battery powered vehicle, even without a catalyst.

  20. Hybridization and extinction.

    Science.gov (United States)

    Todesco, Marco; Pascual, Mariana A; Owens, Gregory L; Ostevik, Katherine L; Moyers, Brook T; Hübner, Sariel; Heredia, Sylvia M; Hahn, Min A; Caseys, Celine; Bock, Dan G; Rieseberg, Loren H

    2016-08-01

    Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization-induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization-prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities.

  1. Manage Stress

    Science.gov (United States)

    ... Manage Stress Print This Topic En español Manage Stress Browse Sections The Basics Overview Signs and Health ... and Health Effects What are the signs of stress? When people are under stress, they may feel: ...

  2. Stress Incontinence

    Science.gov (United States)

    Stress incontinence Overview Urinary incontinence is the unintentional loss of urine. Stress incontinence happens when physical movement or activity — such ... coughing, sneezing, running or heavy lifting — puts pressure (stress) on your bladder. Stress incontinence is not related ...

  3. Spoof Plasmon Hybridization

    CERN Document Server

    Zhang, Jingjing; Luo, Yu; Shen, Xiaopeng; Maier, Stefan A; Cui, Tie Jun

    2016-01-01

    Plasmon hybridization between closely spaced nanoparticles yields new hybrid modes not found in individual constituents, allowing for the engineering of resonance properties and field enhancement capabilities of metallic nanostructure. Experimental verifications of plasmon hybridization have been thus far mostly limited to optical frequencies, as metals cannot support surface plasmons at longer wavelengths. Here, we introduce the concept of 'spoof plasmon hybridization' in highly conductive metal structures and investigate experimentally the interaction of localized surface plasmon resonances (LSPR) in adjacent metal disks corrugated with subwavelength spiral patterns. We show that the hybridization results in the splitting of spoof plasmon modes into bonding and antibonding resonances analogous to molecular orbital rule and plasmonic hybridization in optical spectrum. These hybrid modes can be manipulated to produce enormous field enhancements (larger than 5000) by tuning the separation between disks or alte...

  4. Oxidative Stress in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Varsha Shukla

    2011-01-01

    Full Text Available It has been demonstrated that oxidative stress has a ubiquitous role in neurodegenerative diseases. Major source of oxidative stress due to reactive oxygen species (ROS is related to mitochondria as an endogenous source. Although there is ample evidence from tissues of patients with neurodegenerative disorders of morphological, biochemical, and molecular abnormalities in mitochondria, it is still not very clear whether the oxidative stress itself contributes to the onset of neurodegeneration or it is part of the neurodegenerative process as secondary manifestation. This paper begins with an overview of how oxidative stress occurs, discussing various oxidants and antioxidants, and role of oxidative stress in diseases in general. It highlights the role of oxidative stress in neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's diseases and amyotrophic lateral sclerosis. The last part of the paper describes the role of oxidative stress causing deregulation of cyclin-dependent kinase 5 (Cdk5 hyperactivity associated with neurodegeneration.

  5. Integrated approach for hybrid rocket technology development

    Science.gov (United States)

    Barato, Francesco; Bellomo, Nicolas; Pavarin, Daniele

    2016-11-01

    Hybrid rocket motors tend generally to be simple from a mechanical point of view but difficult to optimize because of their complex and still not well understood cross-coupled physics. This paper addresses the previous issue presenting the integrated approach established at University of Padua to develop hybrid rocket based systems. The methodology tightly combines together system analysis and design, numerical modeling from elementary to sophisticated CFD, and experimental testing done with incremental philosophy. As an example of the approach, the paper presents the experience done in the successful development of a hybrid rocket booster designed for rocket assisted take off operations. It is thought that following the proposed approach and selecting carefully the most promising applications it is possible to finally exploit the major advantages of hybrid rocket motors as safety, simplicity, low cost and reliability.

  6. Hybrid neural network models of transducers

    Science.gov (United States)

    Xie, Shilin; Zhang, Xinong; Chen, Shenglai; Zhu, Changchun

    2011-10-01

    A hybrid neural network (NN) approach is proposed and applied to modeling of transducers in the paper. The modeling procedures are also presented in detail. First, the simulated studies on the modeling of single input-single output and multi input-multi output transducers are conducted respectively by use of the developed hybrid NN scheme. Secondly, the hybrid NN modeling approach is utilized to characterize a six-axis force sensor prototype based on the measured data. The results show that the hybrid NN approach can significantly improve modeling precision in comparison with the conventional modeling method. In addition, the method is superior to NN black-box modeling because the former possesses smaller network scale, higher convergence speed, higher model precision and better generalization performance.

  7. Safety Verification for Probabilistic Hybrid Systems

    DEFF Research Database (Denmark)

    Zhang, Lijun; She, Zhikun; Ratschan, Stefan;

    2010-01-01

    The interplay of random phenomena and continuous real-time control deserves increased attention for instance in wireless sensing and control applications. Safety verification for such systems thus needs to consider probabilistic variations of systems with hybrid dynamics. In safety verification...... hybrid systems and develop a general abstraction technique for verifying probabilistic safety problems. This gives rise to the first mechanisable technique that can, in practice, formally verify safety properties of non-trivial continuous-time stochastic hybrid systems-without resorting to point...... of classical hybrid systems we are interested in whether a certain set of unsafe system states can be reached from a set of initial states. In the probabilistic setting, we may ask instead whether the probability of reaching unsafe states is below some given threshold. In this paper, we consider probabilistic...

  8. Safety Verification for Probabilistic Hybrid Systems

    DEFF Research Database (Denmark)

    Zhang, Lijun; She, Zhikun; Ratschan, Stefan;

    2012-01-01

    The interplay of random phenomena and continuous dynamics deserves increased attention, especially in the context of wireless sensing and control applications. Safety verification for such systems thus needs to consider probabilistic variants of systems with hybrid dynamics. In safety verification...... hybrid systems and develop a general abstraction technique for verifying probabilistic safety problems. This gives rise to the first mechanisable technique that can, in practice, formally verify safety properties of non-trivial continuous-time stochastic hybrid systems. Moreover, being based...... of classical hybrid systems, we are interested in whether a certain set of unsafe system states can be reached from a set of initial states. In the probabilistic setting, we may ask instead whether the probability of reaching unsafe states is below some given threshold. In this paper, we consider probabilistic...

  9. Diallel analysis in white oat cultivars subjected to water stress.

    Directory of Open Access Journals (Sweden)

    Guilherme Ribeiro

    2011-01-01

    Full Text Available The goal of this work was to determine the combining ability of three white oat parental genotypes (UPF 18, URS21and URS 22 and to estimate the heterosis of F1 hybrids in two conditions, with and without water stress. The results indicate a largeeffect of the environment on the evaluated characters (cycle, leaf area, plant stature, grain yield per plant, main panicle weight andnumber of grains of the main panicle. The condition without stress was the most efficient for the selection of superior genotypes.Based on the general and specific combining ability, the cultivar URS 22 was shown to be indicated for cycle and stature reduction,while UPF 18 lead to increases in leaf area, main panicle weight and number of grains of the main panicle. The specific cross URS22 x URS 21 was the best for the selection of superior genotypes.

  10. Hybrid metric-Palatini stars

    Science.gov (United States)

    Danilǎ, Bogdan; Harko, Tiberiu; Lobo, Francisco S. N.; Mak, M. K.

    2017-02-01

    We consider the internal structure and the physical properties of specific classes of neutron, quark and Bose-Einstein condensate stars in the recently proposed hybrid metric-Palatini gravity theory, which is a combination of the metric and Palatini f (R ) formalisms. It turns out that the theory is very successful in accounting for the observed phenomenology, since it unifies local constraints at the Solar System level and the late-time cosmic acceleration, even if the scalar field is very light. In this paper, we derive the equilibrium equations for a spherically symmetric configuration (mass continuity and Tolman-Oppenheimer-Volkoff) in the framework of the scalar-tensor representation of the hybrid metric-Palatini theory, and we investigate their solutions numerically for different equations of state of neutron and quark matter, by adopting for the scalar field potential a Higgs-type form. It turns out that the scalar-tensor definition of the potential can be represented as an Clairaut differential equation, and provides an explicit form for f (R ) given by f (R )˜R +Λeff, where Λeff is an effective cosmological constant. Furthermore, stellar models, described by the stiff fluid, radiation-like, bag model and the Bose-Einstein condensate equations of state are explicitly constructed in both general relativity and hybrid metric-Palatini gravity, thus allowing an in-depth comparison between the predictions of these two gravitational theories. As a general result it turns out that for all the considered equations of state, hybrid gravity stars are more massive than their general relativistic counterparts. Furthermore, two classes of stellar models corresponding to two particular choices of the functional form of the scalar field (constant value, and logarithmic form, respectively) are also investigated. Interestingly enough, in the case of a constant scalar field the equation of state of the matter takes the form of the bag model equation of state describing

  11. Henkin and Hybrid Logic

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Huertas, Antonia; Manzano, Maria;

    2014-01-01

    Leon Henkin was not a modal logician, but there is a branch of modal logic that has been deeply influenced by his work. That branch is hybrid logic, a family of logics that extend orthodox modal logic with special proposition symbols (called nominals) that name worlds. This paper explains why...... Henkin’s techniques are so important in hybrid logic. We do so by proving a completeness result for a hybrid type theory called HTT, probably the strongest hybrid logic that has yet been explored. Our completeness result builds on earlier work with a system called BHTT, or basic hybrid type theory...... is due to the first-order perspective, which lies at the heart of Henin’s best known work and hybrid logic....

  12. InvestigatIion on the work stress and psychological status of nursing staff in a general hospital%综合医院护理人员工作压力及心理状况调查

    Institute of Scientific and Technical Information of China (English)

    高桃; 马爱国; 邵丽萍; 汪求真; 王爱敏; 高玉芳

    2013-01-01

    Objective To study the work stress and psychological status of nursing staff as well as their relationship,so as to provide scientific references for alleviating work stress and improving mental health.Methods 532 nurses insome general hospital were chosen by target sampling,and self-designed questionnaire,work stress scale and SCL-90 were used to investigate their basic information,work stress and psychological status.Results Work stress analysis showed that,among 5 dimensions of nursing staff' s work stress,the score of nursing,nursing profession and work was the highest,respectively (2.73 ± 0.62),(2.61 ± 0.61).The score of somatization,obsessive-compulsivesymptoms and interpersonal sensitivity in SCL-90 was respectively (1.80 ± 0.50),(2.07 ± 0.55),(1.82 ± 0.52),higher than the norm which is (1.37 ± 0.48),(1.62 ±0.58),(1.65 ± 0.51),and the differences were statistically significant (t =17.37,15.43,6.49,respectively;P < 0.01) ; the score of depression,paranoid,psychosis,anxiety,hostility,terror in SCL-90 was respectively higher than the norm (P < 0.01).There was no statistically significantdifference of mental health scores between nurses of different genders (P > 0.05).Score of somatization was relatively higher in nursing staff who were over 40 years old,officially employed or nurses-in-charge and above (P < 0.05).Score of interpersonal relationship,anxiety,hostile and horror was relatively higher in nursing staff who were under 40,non-officially employed or below nurses-in-charge (P < 0.05).Logistic regression analysis showed that,professional title,nursing for patients,management and interpersonal relationship,nursing profession and work were the four main influencing factors for nursing staff' s mental health,and the order of importance was professional > nursing profession and work > nursing for patients > management and interpersonal relationship.Conclusions Nursing staff' s work stress is high and their psychological status is not

  13. BSA Hybrid Synthesized Polymer

    Institute of Scientific and Technical Information of China (English)

    Zong Bin LIU; Xiao Pei DENG; Chang Sheng ZHAO

    2006-01-01

    Bovine serum albumin (BSA), a naturally occurring biopolymer, was regarded as a polymeric material to graft to an acrylic acid (AA)-N-vinyl pyrrolidone (NVP) copolymer to form a biomacromolecular hybrid polymer. The hybrid polymer can be blended with polyethersulfone (PES) to increase the hydrophilicity of the PES membrane, which suggested that the hybrid polymer might have a wide application in the modification of biomaterials.

  14. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Ronkko, Mauno; Ravn, Anders P.

    1997-01-01

    a differential action, which allows differential equations as primitive actions. The extension allows us to model hybrid systems with both continuous and discrete behaviour. The main result of this paper is an extension of such a hybrid action system with parallel composition. The extension does not change...... the original meaning of the parallel composition, and therefore also the ordinary action systems can be composed in parallel with the hybrid action systems....

  15. HYBRID VEHICLE CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-06-01

    Full Text Available The hybrid vehicle control system includes a start–stop system for an internal combustion engine. The system works in a hybrid mode and normal vehicle operation. To simplify the start–stop system, there were user new possibilities of a hybrid car, which appeared after the conversion. Results of the circuit design of the proposed system of basic blocks are analyzed.

  16. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  18. General Dentist

    Science.gov (United States)

    ... Some general dentists work in government health services, research programs, higher education, corporations and even the military. ?xml:namespace> What kind of procedures do general dentists provide? ?xml:namespace> Many general dentists are ...

  19. Phase reduction theory for hybrid nonlinear oscillators

    Science.gov (United States)

    Shirasaka, Sho; Kurebayashi, Wataru; Nakao, Hiroya

    2017-01-01

    Hybrid dynamical systems characterized by discrete switching of smooth dynamics have been used to model various rhythmic phenomena. However, the phase reduction theory, a fundamental framework for analyzing the synchronization of limit-cycle oscillations in rhythmic systems, has mostly been restricted to smooth dynamical systems. Here we develop a general phase reduction theory for weakly perturbed limit cycles in hybrid dynamical systems that facilitates analysis, control, and optimization of nonlinear oscillators whose smooth models are unavailable or intractable. On the basis of the generalized theory, we analyze injection locking of hybrid limit-cycle oscillators by periodic forcing and reveal their characteristic synchronization properties, such as ultrafast and robust entrainment to the periodic forcing and logarithmic scaling at the synchronization transition. We also illustrate the theory by analyzing the synchronization dynamics of a simple physical model of biped locomotion.

  20. Hybrid Unifying Variable Supernetwork Model

    Institute of Scientific and Technical Information of China (English)

    LIU; Qiang; FANG; Jin-qing; LI; Yong

    2015-01-01

    In order to compare new phenomenon of topology change,evolution,hybrid ratio and network characteristics of unified hybrid network theoretical model with unified hybrid supernetwork model,this paper constructed unified hybrid variable supernetwork model(HUVSM).The first layer introduces a hybrid ratio dr,the

  1. Large Unifying Hybrid Supernetwork Model

    Institute of Scientific and Technical Information of China (English)

    LIU; Qiang; FANG; Jin-qing; LI; Yong

    2015-01-01

    For depicting multi-hybrid process,large unifying hybrid network model(so called LUHNM)has two sub-hybrid ratios except dr.They are deterministic hybrid ratio(so called fd)and random hybrid ratio(so called gr),respectively.

  2. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  3. Hybrid Rocket Technology

    National Research Council Canada - National Science Library

    Sankaran Venugopal; K K Rajesh; V Ramanujachari

    2011-01-01

    With their unique operational characteristics, hybrid rockets can potentially provide safer, lower-cost avenues for spacecraft and missiles than the current solid propellant and liquid propellant systems...

  4. Hybrid FOSS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong researchers are continuing their efforts to further develop FOSS technologies. A hybrid FOSS technique (HyFOSS) employs conventional continuous grating...

  5. The maintenance of hybrids by parasitism in a freshwater snail.

    Science.gov (United States)

    Guttel, Yonathan; Ben-Ami, Frida

    2014-11-01

    Hybrids have often been labelled evolutionary dead-ends due to their lower fertility and viability. However, there is growing awareness that hybridisation between different species may play a constructive role in animal evolution as a means to create variability. Thus, hybridisation and introgression may contribute to adaptive evolution, for example with regards to natural antagonists (parasites, predators, competitors) and adaptation to local environmental conditions. Here we investigated whether parasite intensity contributes to the continuous recreation of hybrids in 74 natural populations of Melanopsis, a complex of freshwater snails with three species. We also examined, under laboratory conditions, whether hybrids and their parental taxa differ in their tolerance of low and high temperatures and salinity levels. Infections were consistently less prevalent in males than in females, and lower in snails from deeper habitats. Infection prevalence in hybrids was significantly lower than in the parental taxa. Low hybrid infection rates could not be explained by sediment type, snail density or geographic distribution of the sampling sites. Interestingly, infected hybrid snails did not show signs of parasite-induced gigantism, whereas all parental taxa did. We found that hybrids mostly coped with extreme temperatures and salinity levels as well as their parental taxa did. Taken together, our results suggest that Melanopsis hybrids perform better in the presence of parasites and environmental stress. This may explain the widespread and long-term occurrence of Melanopsis hybrids as evidenced by paleontological and biogeographic data. Hybridisation may be an adaptive host strategy, reducing infection rates and resisting gigantism.

  6. HOPIS: hybrid omnidirectional and perspective imaging system for mobile robots.

    Science.gov (United States)

    Lin, Huei-Yung; Wang, Min-Liang

    2014-09-04

    In this paper, we present a framework for the hybrid omnidirectional and perspective robot vision system. Based on the hybrid imaging geometry, a generalized stereo approach is developed via the construction of virtual cameras. It is then used to rectify the hybrid image pair using the perspective projection model. The proposed method not only simplifies the computation of epipolar geometry for the hybrid imaging system, but also facilitates the stereo matching between the heterogeneous image formation. Experimental results for both the synthetic data and real scene images have demonstrated the feasibility of our approach.

  7. On a Variational Approach to Optimization of Hybrid Mechanical Systems

    Directory of Open Access Journals (Sweden)

    Vadim Azhmyakov

    2010-01-01

    Full Text Available This paper deals with multiobjective optimization techniques for a class of hybrid optimal control problems in mechanical systems. We deal with general nonlinear hybrid control systems described by boundary-value problems associated with hybrid-type Euler-Lagrange or Hamilton equations. The variational structure of the corresponding solutions makes it possible to reduce the original “mechanical” problem to an auxiliary multiobjective programming reformulation. This approach motivates possible applications of theoretical and computational results from multiobjective optimization related to the original dynamical optimization problem. We consider first order optimality conditions for optimal control problems governed by hybrid mechanical systems and also discuss some conceptual algorithms.

  8. Stress relief of transition zones

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J.; van Rooyen, D.

    1984-01-01

    This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here concentrated on the identification of an optimal, in-situ stress relief treatment.

  9. Role of Sphingomonas sp. Strain Fr1 PhyR-NepR-σEcfG Cascade in General Stress Response and Identification of a Negative Regulator of PhyR▿†

    Science.gov (United States)

    Kaczmarczyk, Andreas; Campagne, Sébastien; Danza, Francesco; Metzger, Lisa C.; Vorholt, Julia A.; Francez-Charlot, Anne

    2011-01-01

    The general stress response in Alphaproteobacteria was recently described to depend on the alternative sigma factor σEcfG, whose activity is regulated by its anti-sigma factor NepR. The response regulator PhyR, in turn, regulates NepR activity in a partner-switching mechanism according to which phosphorylation of PhyR triggers sequestration of NepR by the sigma factor-like effector domain of PhyR. Although genes encoding predicted histidine kinases can often be found associated with phyR, little is known about their role in modulation of PhyR phosphorylation status. We demonstrate here that the PhyR-NepR-σEcfG cascade is important for multiple stress resistance and competitiveness in the phyllosphere in a naturally abundant plant epiphyte, Sphingomonas sp. strain Fr1, and provide evidence that the partner switching mechanism is conserved. We furthermore identify a gene, designated phyP, encoding a predicted histidine kinase at the phyR locus as essential. Genetic epistasis experiments suggest that PhyP acts upstream of PhyR, keeping PhyR in an unphosphorylated, inactive state in nonstress conditions, strictly depending on the predicted phosphorylatable site of PhyP, His-341. In vitro experiments show that Escherichia coli inner membrane fractions containing PhyP disrupt the PhyR-P/NepR complex. Together with the fact that PhyP lacks an obvious ATPase domain, these results are in agreement with PhyP functioning as a phosphatase of PhyR, rather than a kinase. PMID:21949070

  10. Role of Sphingomonas sp. strain Fr1 PhyR-NepR-σEcfG cascade in general stress response and identification of a negative regulator of PhyR.

    Science.gov (United States)

    Kaczmarczyk, Andreas; Campagne, Sébastien; Danza, Francesco; Metzger, Lisa C; Vorholt, Julia A; Francez-Charlot, Anne

    2011-12-01

    The general stress response in Alphaproteobacteria was recently described to depend on the alternative sigma factor σ(EcfG), whose activity is regulated by its anti-sigma factor NepR. The response regulator PhyR, in turn, regulates NepR activity in a partner-switching mechanism according to which phosphorylation of PhyR triggers sequestration of NepR by the sigma factor-like effector domain of PhyR. Although genes encoding predicted histidine kinases can often be found associated with phyR, little is known about their role in modulation of PhyR phosphorylation status. We demonstrate here that the PhyR-NepR-σ(EcfG) cascade is important for multiple stress resistance and competitiveness in the phyllosphere in a naturally abundant plant epiphyte, Sphingomonas sp. strain Fr1, and provide evidence that the partner switching mechanism is conserved. We furthermore identify a gene, designated phyP, encoding a predicted histidine kinase at the phyR locus as essential. Genetic epistasis experiments suggest that PhyP acts upstream of PhyR, keeping PhyR in an unphosphorylated, inactive state in nonstress conditions, strictly depending on the predicted phosphorylatable site of PhyP, His-341. In vitro experiments show that Escherichia coli inner membrane fractions containing PhyP disrupt the PhyR-P/NepR complex. Together with the fact that PhyP lacks an obvious ATPase domain, these results are in agreement with PhyP functioning as a phosphatase of PhyR, rather than a kinase.

  11. Carboxylated nitrile butadiene rubber/hybrid filler composites

    Directory of Open Access Journals (Sweden)

    Ahmad Mousa

    2012-08-01

    Full Text Available The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH. Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR of the composites. The degree of curing ΔM (maximum torque-minimum torque as a function of hybrid filler as derived from moving die rheometer (MDR is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM.

  12. The 'simple' general dental anaesthetic

    African Journals Online (AJOL)

    The patient who receives dental treatment under general anaesthesia is usually a child, one with special ... under various anaesthetic techniques and .... preoperatively in the presence of a parent or .... helpful in counteracting the stress caused.

  13. Hybrid metric-Palatini stars

    CERN Document Server

    Danila, Bogdan; Lobo, Francisco S N; Mak, M K

    2016-01-01

    We consider the internal structure and the physical properties of specific classes of neutron, quark and Bose-Einstein Condensate stars in the hybrid metric-Palatini gravity theory, which is a combination of the metric and Palatini $f(R)$ formalisms. The theory is very successful in accounting for the observed phenomenology, since it unifies local constraints at the Solar System level and the late-time cosmic acceleration, even if the scalar field is very light. We derive the equilibrium equations for a spherically symmetric configuration (mass continuity and Tolman-Oppenheimer-Volkoff) in the framework of hybrid metric-Palatini theory, and we investigate their solutions numerically for different equations of state of neutron and quark matter, by adopting for the scalar field potential a Higgs-type form. Stellar models, described by the stiff fluid, radiation-like, the bag model and the Bose-Einstein Condensate equations of state are explicitly constructed in both General Relativity and hybrid metric-Palatini...

  14. Hybrid manifold embedding.

    Science.gov (United States)

    Liu, Yang; Liu, Yan; Chan, Keith C C; Hua, Kien A

    2014-12-01

    In this brief, we present a novel supervised manifold learning framework dubbed hybrid manifold embedding (HyME). Unlike most of the existing supervised manifold learning algorithms that give linear explicit mapping functions, the HyME aims to provide a more general nonlinear explicit mapping function by performing a two-layer learning procedure. In the first layer, a new clustering strategy called geodesic clustering is proposed to divide the original data set into several subsets with minimum nonlinearity. In the second layer, a supervised dimensionality reduction scheme called locally conjugate discriminant projection is performed on each subset for maximizing the discriminant information and minimizing the dimension redundancy simultaneously in the reduced low-dimensional space. By integrating these two layers in a unified mapping function, a supervised manifold embedding framework is established to describe both global and local manifold structure as well as to preserve the discriminative ability in the learned subspace. Experiments on various data sets validate the effectiveness of the proposed method.

  15. Hybrid methods for cybersecurity analysis :

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Warren Leon,; Dunlavy, Daniel M.

    2014-01-01

    years to hours and days for the application of new modeling and analysis capabilities to emerging threats. The development and deployment framework has been generalized into the Hybrid Framework and incor- porated into several LDRD, WFO, and DOE/CSL projects and proposals. And most importantly, the Hybrid project has provided Sandia security analysts with new, scalable, extensible analytic capabilities that have resulted in alerts not detectable using their previous work ow tool sets.

  16. Original Framework for Optimizing Hybrid Energy Supply

    Directory of Open Access Journals (Sweden)

    Amevi Acakpovi

    2016-01-01

    Full Text Available This paper proposes an original framework for optimizing hybrid energy systems. The recent growth of hybrid energy systems in remote areas across the world added to the increasing cost of renewable energy has triggered the inevitable development of hybrid energy systems. Hybrid energy systems always pose a problem of optimization of cost which has been approached with different perspectives in the recent past. This paper proposes a framework to guide the techniques of optimizing hybrid energy systems in general. The proposed framework comprises four stages including identification of input variables for energy generation, establishment of models of energy generation by individual sources, development of artificial intelligence, and finally summation of selected sources. A case study of a solar, wind, and hydro hybrid system was undertaken with a linear programming approach. Substantial results were obtained with regard to how load requests were constantly satisfied while minimizing the cost of electricity. The developed framework gained its originality from the fact that it has included models of individual sources of energy that even make the optimization problem more complex. This paper also has impacts on the development of policies which will encourage the integration and development of renewable energies.

  17. A new type of hybrid vehicle in Japan; Un nouveau type de vehicule hybride au Japon

    Energy Technology Data Exchange (ETDEWEB)

    Henry, P.

    2004-04-01

    During the 37. edition of the Tokyo Motor Show in October 2003, several fuel cell hybrid vehicles were presented by Japanese car makers who grant considerable budgets to develop less polluting vehicles. The trend chosen by Japanese car manufacturers concerns the hybrid system combining fuel cell and battery. Stress has been put also on intelligent systems for navigation and safety but also on the design and comfort. However, even if the environment protection is the main challenge of the Japanese automotive industry, the driving pleasure remains the most profitable medium-term market to be exploitable by industrialists. (J.S.)

  18. Mechanical Properties of Layered Hybrid Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    YUAN Hai-qing; CHEN Jing-tao; ZHU Ji-dong

    2003-01-01

    To improve the mechanical properties of concrete,Layered Hybrid Fiber Reinforced Concrete (LHFRC) was developed in this paper.Through comparative tests,the effects of layered hybrid fibers on a series of mechanical properties of concrete were discussed.The mechanical properties include compressive strength,tensile strength,flexural strength,compressive stress-strain relationship,flexural toughness and cracking resistance of concrete.The testing results and analysis demonstrate that layered hybrid fibers can significantly improve the flexural strength,toughness and cracking resistance of concrete while the cost of concrete increases slightly.

  19. Caregiver Stress

    Science.gov (United States)

    ... Home A-Z Health Topics Caregiver stress Caregiver stress > A-Z Health Topics Caregiver fact sheet (PDF, ... receive Publications email updates Enter email Submit Caregiver stress Caregivers care for someone with an illness, injury, ...

  20. Potential Climate and Ozone Impacts From Hybrid Rocket Engine Emissions

    Science.gov (United States)

    Ross, M.

    2009-12-01

    Hybrid rocket engines that use N2O as an oxidizer and a solid hydrocarbon (such as rubber) as a fuel are relatively new. Little is known about the composition of such hybrid engine emissions. General principles and visual inspection of hybrid plumes suggest significant soot and possibly NO emissions. Understanding hybrid rocket emissions is important because of the possibility that a fleet of hybrid powered suborbital rockets will be flying on the order of 1000 flights per year by 2020. The annual stratospheric emission for these rockets would be about 10 kilotons, equal to present day solid rocket motor (SRM) emissions. We present a preliminary analysis of the magnitude of (1) the radiative forcing from soot emissions and (2) the ozone depletion from soot and NO emissions associated with such a fleet of suborbital hybrid rockets. Because the details of the composition of hybrid emissions are unknown, it is not clear if the ozone depletion caused by these hybrid rockets would be more or less than the ozone depletion from SRMs. We also consider the climate implications associated with the N2O production and use requirements for hybrid rockets. Finally, we identify the most important data collection and modeling needs that are required to reliably assess the complete range of environmental impacts of a fleet of hybrid rockets.

  1. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-05-15

    Hybrid cardiac single photon emission computed tomography (SPECT)/CT imaging allows combined assessment of anatomical and functional aspects of cardiac disease. In coronary artery disease (CAD), hybrid SPECT/CT imaging allows detection of coronary artery stenosis and myocardial perfusion abnormalities. The clinical value of hybrid imaging has been documented in several subsets of patients. In selected groups of patients, hybrid imaging improves the diagnostic accuracy to detect CAD compared to the single imaging techniques. Additionally, this approach facilitates functional interrogation of coronary stenoses and guidance with regard to revascularization procedures. Moreover, the anatomical information obtained from CT coronary angiography or coronary artery calcium scores (CACS) adds prognostic information over perfusion data from SPECT. The use of cardiac hybrid imaging has been favoured by the dissemination of dedicated hybrid systems and the release of dedicated image fusion software, which allow simple patient throughput for hybrid SPECT/CT studies. Further technological improvements such as more efficient detector technology to allow for low-radiation protocols, ultra-fast image acquisition and improved low-noise image reconstruction algorithms will be instrumental to further promote hybrid SPECT/CT in research and clinical practice. (orig.)

  2. Hybrid intelligent engineering systems

    CERN Document Server

    Jain, L C; Adelaide, Australia University of

    1997-01-01

    This book on hybrid intelligent engineering systems is unique, in the sense that it presents the integration of expert systems, neural networks, fuzzy systems, genetic algorithms, and chaos engineering. It shows that these new techniques enhance the capabilities of one another. A number of hybrid systems for solving engineering problems are presented.

  3. A Hybrid Imagination

    DEFF Research Database (Denmark)

    Jamison, Andrew; Christensen, Steen Hyldgaard; Botin, Lars

    contexts, or sites, for mixing scientific knowledge and technical skills from different fields and social domains into new combinations, thus fostering what the authors term a “hybrid imagination”. Such a hybrid imagination is especially important today, as a way to counter the competitive and commercial...

  4. Editorial: Hybrid Systems

    DEFF Research Database (Denmark)

    Olderog, Ernst-Rüdiger; Ravn, Anders Peter

    2007-01-01

    An introduction to three papers in a special issue on Hybrid Systems. These paper were first presented at an IFIP WG 2.2 meeting in Skagen 2005.......An introduction to three papers in a special issue on Hybrid Systems. These paper were first presented at an IFIP WG 2.2 meeting in Skagen 2005....

  5. Changes in rRNA levels during stress invalidates results from mRNA blotting: Fluorescence in situ rRNA hybridization permits renormalization for estimation of cellular mRNA levels

    DEFF Research Database (Denmark)

    Hansen, M.C.; Nielsen, A.K.; Molin, Søren

    2001-01-01

    experiments, in which mRNA levels routinely are normalized to a fixed amount of extracted total RNA. The cellular levels of specific mRNA species were estimated using a renormalization with the total RNA content per cell. By a combination of fluorescence in situ rRNA hybridization, which estimates...... the relative level of rRNA per cell, and slot blotting to rRNA probes, which estimates the level of rRNA per extracted total RNA, the amount of RNA per cell was calculated in a series of heat shock experiments with the gram-positive bacterium Lactococcus lactis. It was found that the level of rRNA per cell...... in the hrcA-grpE-dnaK operon was analyzed. The hybridization data suggested a complex heat shock regulation indicating that the mRNA levels continued to rise after 30 min, but after renormalization the calculated average cellular levels exhibited a much simpler induction pattern, eventually attaining...

  6. Probabilistic Analysis Methods for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Frier, Christian; Heiselberg, Per

    This paper discusses a general approach for the application of probabilistic analysis methods in the design of ventilation systems. The aims and scope of probabilistic versus deterministic methods are addressed with special emphasis on hybrid ventilation systems. A preliminary application of stoc...... of stochastic differential equations is presented comprising a general heat balance for an arbitrary number of loads and zones in a building to determine the thermal behaviour under random conditions....

  7. Controle genético e tolerância ao estresse de calor em populações híbridas e em cultivares de trigo Genetic control and tolerance to the heat stress in wheat hybrid population and cultivars

    Directory of Open Access Journals (Sweden)

    Moacil Alves de Souza

    2001-10-01

    Full Text Available O objetivo deste trabalho foi obter informações sobre o controle genético da produtividade de grãos de trigo sob condições de estresse de calor, o grau de tolerância ao estresse de calor de algumas cultivares e linhagens e a identificação de populações segregantes promissoras para a obtenção de linhagens adaptadas às condições da região central do Brasil. Foram avaliados 13 parentais e 40 populações provenientes de um dialelo parcial, nas gerações F1 e F2 em condições de campo, em Lavras e Patos de Minas, MG, com as semeaduras feitas no verão (fevereiro e no inverno (maio. Houve diferença de tolerância ao calor entre os parentais e entre as populações híbridas quanto ao caráter produção de grãos, e ambos os efeitos aditivos e não-aditivos foram importantes no controle genético deste caráter na presença ou ausência de calor. Apesar da ocorrência de interações populações x épocas de semeadura, a alta repetibilidade dos efeitos da capacidade geral de combinação permite inferir a possibilidade de acelerar os programas de melhoramento na região, efetuando-se a seleção tanto na época de verão quanto no inverno.The objective of this work was to get information about the genetic control of the grain yield under heat stress conditions, the tolerance of cultivar and the identification of promising segregation populations for selections of lines adapted to the conditions of the central region of Brazil. Thirteen parents and 40 populations in F1 and F2 generations derived by partial diallel crosses were evaluated. The experiments were conducted under field conditions in Lavras and Patos de Minas, MG, Brazil, sowing the seeds in the summertime (February and in the winter (May. There was difference of heat tolerance among parents and hybrid populations for grain yield character, and both additive and non-additive effects were important in the genetic control of grain yield character in the presence or absence

  8. Hybrid reactors. [Fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.

    1980-09-09

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  9. Hybrid propulsion technology program

    Science.gov (United States)

    1990-01-01

    Technology was identified which will enable application of hybrid propulsion to manned and unmanned space launch vehicles. Two design concepts are proposed. The first is a hybrid propulsion system using the classical method of regression (classical hybrid) resulting from the flow of oxidizer across a fuel grain surface. The second system uses a self-sustaining gas generator (gas generator hybrid) to produce a fuel rich exhaust that was mixed with oxidizer in a separate combustor. Both systems offer cost and reliability improvement over the existing solid rocket booster and proposed liquid boosters. The designs were evaluated using life cycle cost and reliability. The program consisted of: (1) identification and evaluation of candidate oxidizers and fuels; (2) preliminary evaluation of booster design concepts; (3) preparation of a detailed point design including life cycle costs and reliability analyses; (4) identification of those hybrid specific technologies needing improvement; and (5) preperation of a technology acquisition plan and large scale demonstration plan.

  10. Stress and Protists: No life without stress

    Science.gov (United States)

    Slaveykova, Vera; Sonntag, Bettina; Gutiérrez, Juan Carlos

    2017-01-01

    We report a summary of the symposium “Stress and Protists: No life without stress”, which was held in September 2015 on the VII European Congress of Protistology in partnership with the International Society of Protistologists (Seville, Spain). We present an overview on general comments and concepts on cellular stress which can be also applied to any protist. Generally, various environmental stressors may induce similar cell responses in very different protists. Two main topics are reported in this manuscript: (i) metallic nanoparticles as environmental pollutants and stressors for aquatic protists, and (ii) ultraviolet radiation – induced stress and photoprotective strategies in ciliates. Model protists such as Chlamydomonas reinhardtii and Tetrahymena thermophila were used to assess stress caused by nanoparticles while stress caused by ultraviolet radiation was tested with free living planktonic ciliates as well as with the symbiont-bearing model ciliate Paramecium bursaria. For future studies, we suggest more intensive analyses on protist stress responses to specific environmental abiotic and/or biotic stressors at molecular and genetic levels up to ecological consequences and food web dynamics. PMID:27365178

  11. The disadvantages of being a hybrid during drought: A combined analysis of plant morphology, physiology and leaf proteome in maize.

    Science.gov (United States)

    Holá, Dana; Benešová, Monika; Fischer, Lukáš; Haisel, Daniel; Hnilička, František; Hniličková, Helena; Jedelský, Petr L; Kočová, Marie; Procházková, Dagmar; Rothová, Olga; Tůmová, Lenka; Wilhelmová, Naďa

    2017-01-01

    A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response. The results clearly showed that the four examined genotypes have completely different strategies for coping with limited water availability and that the inherent properties of the F1 hybrids, i.e. positive heterosis in morphological parameters (or, more generally, a larger plant body) becomes a distinct disadvantage when the water supply is limited. However, although a greater loss of photosynthetic efficiency was an inherent disadvantage, the precise causes and consequences of the original predisposition towards faster growth and biomass accumulation differed even between reciprocal hybrids. Both maternal and paternal parents could be imitated by their progeny in some aspects of the drought response (e.g., the absence of general protein down-regulation, changes in the levels of some carbon fixation or other photosynthetic proteins). Nevertheless, other features (e.g., dehydrin or light-harvesting protein contents, reduced chloroplast proteosynthesis) were quite unique to a particular hybrid. Our study also confirmed that the strategy for leaving stomata open even when the water supply is limited (coupled to a smaller body size and some other physiological properties), observed in one of our inbred lines, is associated with drought-resistance not only during mild drought (as we showed previously) but also during more severe drought conditions.

  12. Predominant Expression of Hybrid N-Glycans Has Distinct Cellular Roles Relative to Complex and Oligomannose N-Glycans

    Directory of Open Access Journals (Sweden)

    M. Kristen Hall

    2016-06-01

    Full Text Available Glycosylation modulates growth, maintenance, and stress signaling processes. Consequently, altered N-glycosylation is associated with reduced fitness and disease. Therefore, expanding our understanding of N-glycans in altering biological processes is of utmost interest. Herein, clustered regularly interspaced short palindromic repeats/caspase9 (CRISPR/Cas9 technology was employed to engineer a glycosylation mutant Chinese Hamster Ovary (CHO cell line, K16, which expresses predominantly hybrid type N-glycans. This newly engineered cell line enabled us to compare N-glycan effects on cellular properties of hybrid type N-glycans, to the well-established Pro−5 and Lec1 cell lines, which express complex and oligomannose types of N-glycans, respectively. Lectin binding studies revealed the predominant N-glycan expressed in K16 is hybrid type. Cell dissociation and migration assays demonstrated the greatest strength of cell–cell adhesion and fastest migratory rates for oligomannose N-glycans, and these properties decreased as oligomannose type were converted to hybrid type, and further decreased upon conversion to complex type. Next, we examined the roles of three general types of N-glycans on ectopic expression of E-cadherin, a cell–cell adhesion protein. Microscopy revealed more functional E-cadherin at the cell–cell border when N-glycans were oligomannose and these levels decreased as the oligomannose N-glycans were processed to hybrid and then to complex. Thus, we provide evidence that all three general types of N-glycans impact plasma membrane architecture and cellular properties.

  13. A global hybrid coupled model based on atmosphere-SST feedbacks

    Energy Technology Data Exchange (ETDEWEB)

    Cimatoribus, Andrea A.; Drijfhout, Sybren S. [Royal Netherlands Meteorological Institute, De Bilt (Netherlands); Dijkstra, Henk A. [Utrecht University, Institute for Marine and Atmospheric Research Utrecht, Utrecht (Netherlands)

    2012-02-15

    A global hybrid coupled model is developed, with the aim of studying the effects of ocean-atmosphere feedbacks on the stability of the Atlantic meridional overturning circulation. The model includes a global ocean general circulation model and a statistical atmosphere model. The statistical atmosphere model is based on linear regressions of data from a fully coupled climate model on sea surface temperature both locally and hemispherically averaged, being the footprint of Atlantic meridional overturning variability. It provides dynamic boundary conditions to the ocean model for heat, freshwater and wind-stress. A basic but consistent representation of ocean-atmosphere feedbacks is captured in the hybrid coupled model and it is more than 10 times faster than the fully coupled climate model. The hybrid coupled model reaches a steady state with a climate close to the one of the fully coupled climate model, and the two models also have a similar response (collapse) of the Atlantic meridional overturning circulation to a freshwater hosing applied in the northern North Atlantic. (orig.)

  14. Genetic incompatibility dampens hybrid fertility more than hybrid viability: yeast as a case study.

    Directory of Open Access Journals (Sweden)

    Meibo Xu

    Full Text Available Genetic incompatibility is believed to be the major cause of postzygotic reproductive isolation. Despite huge efforts seeking for speciation-related incompatibilities in the past several decades, a general understanding of how genetic incompatibility evolves in affecting hybrid fitness is not available, primarily due to the fact that the number of known incompatibilities is small. Instead of further mapping specific incompatible genes, in this paper we aimed to know the overall effects of incompatibility on fertility and viability, the two aspects of fitness, by examining 89 gametes produced by yeast S. cerevisiae-S. paradoxus F1 hybrids. Homozygous F2 hybrids formed by autodiploidization of F1 gametes were subject to tests for growth rate and sporulation efficiency. We observed much stronger defects in sporulation than in clonal growth for every single F2 hybrid strain, indicating that genetic incompatibility affects hybrid fertility more than hybrid viability in yeast. We related this finding in part to the fast-evolving nature of meiosis-related genes, and proposed that the generally low expression levels of these genes might be a cause of the observation.

  15. Arsenic-induced stress activates sulfur metabolism in different organs of garlic (Allium sativum L.) plants accompanied by a general decline of the NADPH-generating systems in roots.

    Science.gov (United States)

    Ruíz-Torres, Carmelo; Feriche-Linares, Rafael; Rodríguez-Ruíz, Marta; Palma, José M; Corpas, Francisco J

    2017-04-01

    Arsenic (As) contamination is a major environmental problem which affects most living organisms from plants to animals. This metalloid poses a health risk for humans through its accumulation in crops and water. Using garlic (Allium sativum L.) plants as model crop exposed to 200μM arsenate, a comparative study among their main organs (roots and shoots) was made. The analysis of arsenic, glutathione (GSH), phytochelatins (PCs) and lipid peroxidation contents with the activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate-glutathione cycle), and the main components of the NADPH-generating system, including glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), NADP-malic enzyme (NADP-ME) and NADP-isocitrate dehydrogenase (NADP-ICDH) was carried out. Data showed a correlation among arsenic accumulation in the different organs, PCs content and the antioxidative response, with a general decline of the NADPH-generating systems in roots. Overall, our results demonstrate that there are clear connections between arsenic uptake, increase of their As-chelating capacity in roots and a decline of antioxidative enzyme activities (catalase and the ascorbate peroxidase) whose alteration provoked As-induced oxidative stress. Thus, the data suggest that roots act as barrier of arsenic mediated by a prominent sulfur metabolism which is characterized by the biosynthesis of high amount of PCs. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Hybrid uncertainty-based design optimization and its application to hybrid rocket motors for manned lunar landing

    Directory of Open Access Journals (Sweden)

    Hao Zhu

    2017-04-01

    Full Text Available Design reliability and robustness are getting increasingly important for the general design of aerospace systems with many inherently uncertain design parameters. This paper presents a hybrid uncertainty-based design optimization (UDO method developed from probability theory and interval theory. Most of the uncertain design parameters which have sufficient information or experimental data are classified as random variables using probability theory, while the others are defined as interval variables with interval theory. Then a hybrid uncertainty analysis method based on Monte Carlo simulation and Taylor series interval analysis is developed to obtain the uncertainty propagation from the design parameters to system responses. Three design optimization strategies, including deterministic design optimization (DDO, probabilistic UDO and hybrid UDO, are applied to the conceptual design of a hybrid rocket motor (HRM used as the ascent propulsion system in Apollo lunar module. By comparison, the hybrid UDO is a feasible method and can be effectively applied to the general design of aerospace systems.

  17. Proton Radioactivity Within a Hybrid Metho d

    Institute of Scientific and Technical Information of China (English)

    张鸿飞

    2016-01-01

    The proton radioactivity half-lives are investigated theoretically within a hybrid method. The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized liquid drop model (GLDM). The penetrability is calculated with the Wentzel-Kramers-Brillouin (WKB) approximation. The spectroscopic factor has been taken into account in half-life calculation, which is obtained by employing the relativistic mean field (RMF) theory combined with the Bardeen-Cooper-Schrieffer (BCS) method. The half-lives within the present hybrid method repro-duced the experimental data very well. Some predictions for proton radioactivity are made for future experiments.

  18. Interface Characteristics of Wood-hybrid Composites

    Institute of Scientific and Technical Information of China (English)

    XUEFenglian; ZHAOGuangjie

    2005-01-01

    In order to understand the current interface characteristics of wood-hybrid composites, this paper starts off from the concept of composite interface and general theory of interface form, then the inner-surface and microstructure of wood and the interface characteristics of composites, such as wood- inorganic, wood-plastic and wood- metal made by electroless plating technique, are concluded and discussed in detail. Meanwhile,on the basis of that, some points of view about how to develop the wood-hybrid composites interface research in the future are also proposed.

  19. Tectonic stress - Models and magnitudes

    Science.gov (United States)

    Solomon, S. C.; Bergman, E. A.; Richardson, R. M.

    1980-01-01

    It is shown that global data on directions of principal stresses in plate interiors can serve as a test of possible plate tectonic force models. Such tests performed to date favor force models in which ridge pushing forces play a significant role. For such models the general magnitude of regional deviatoric stresses is comparable to the 200-300 bar compressive stress exerted by spreading ridges. An alternative approach to estimating magnitudes of regional deviatoric stresses from stress orientations is to seek regions of local stress either demonstrably smaller than or larger than the regional stresses. The regional stresses in oceanic intraplate regions are larger than the 100-bar compression exerted by the Ninetyeast Ridge and less than the bending stresses (not less than 1 kbar) beneath Hawaii.

  20. Data sensitivity in a hybrid STEP/Coulomb model for aftershock forecasting

    Science.gov (United States)

    Steacy, S.; Jimenez Lloret, A.; Gerstenberger, M.

    2014-12-01

    Operational earthquake forecasting is rapidly becoming a 'hot topic' as civil protection authorities seek quantitative information on likely near future earthquake distributions during seismic crises. At present, most of the models in public domain are statistical and use information about past and present seismicity as well as b-value and Omori's law to forecast future rates. A limited number of researchers, however, are developing hybrid models which add spatial constraints from Coulomb stress modeling to existing statistical approaches. Steacy et al. (2013), for instance, recently tested a model that combines Coulomb stress patterns with the STEP (short-term earthquake probability) approach against seismicity observed during the 2010-2012 Canterbury earthquake sequence. They found that the new model performed at least as well as, and often better than, STEP when tested against retrospective data but that STEP was generally better in pseudo-prospective tests that involved data actually available within the first 10 days of each event of interest. They suggested that the major reason for this discrepancy was uncertainty in the slip models and, in particular, in the geometries of the faults involved in each complex major event. Here we test this hypothesis by developing a number of retrospective forecasts for the Landers earthquake using hypothetical slip distributions developed by Steacy et al. (2004) to investigate the sensitivity of Coulomb stress models to fault geometry and earthquake slip, and we also examine how the choice of receiver plane geometry affects the results. We find that the results are strongly sensitive to the slip models and moderately sensitive to the choice of receiver orientation. We further find that comparison of the stress fields (resulting from the slip models) with the location of events in the learning period provides advance information on whether or not a particular hybrid model will perform better than STEP.

  1. Hybrid electric vehicles TOPTEC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-06-21

    This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.

  2. Hybrid systems with constraints

    CERN Document Server

    Daafouz, Jamal; Sigalotti, Mario

    2013-01-01

    Control theory is the main subject of this title, in particular analysis and control design for hybrid dynamic systems.The notion of hybrid systems offers a strong theoretical and unified framework to cope with the modeling, analysis and control design of systems where both continuous and discrete dynamics interact. The theory of hybrid systems has been the subject of intensive research over the last decade and a large number of diverse and challenging problems have been investigated. Nevertheless, many important mathematical problems remain open.This book is dedicated mainly to

  3. Hybrid Bloch Brane

    CERN Document Server

    Bazeia, D; Losano, L

    2016-01-01

    This work reports on models described by two real scalar fields coupled with gravity in the five-dimensional spacetime, with a warped geometry involving one infinite extra dimension. Through a mechanism that smoothly changes a thick brane into a hybrid brane, one investigates the appearance of hybrid branes hosting internal structure, characterized by the splitting on the energy density and the volcano potential, induced by the parameter which controls interactions between the two scalar fields. In particular, we investigate distinct symmetric and asymmetric hybrid brane scenarios.

  4. Hybrid Bloch brane

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Lima, Elisama E.M.; Losano, L. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil)

    2017-02-15

    This work reports on models described by two real scalar fields coupled with gravity in the five-dimensional spacetime, with a warped geometry involving one infinite extra dimension. Through a mechanism that smoothly changes a thick brane into a hybrid brane, one investigates the appearance of hybrid branes hosting internal structure, characterized by the splitting on the energy density and the volcano potential, induced by the parameter which controls interactions between the two scalar fields. In particular, we investigate distinct symmetric and asymmetric hybrid brane scenarios. (orig.)

  5. Hybrid silicon evanescent devices

    Directory of Open Access Journals (Sweden)

    Alexander W. Fang

    2007-07-01

    Full Text Available Si photonics as an integration platform has recently been a focus of optoelectronics research because of the promise of low-cost manufacturing based on the ubiquitous electronics fabrication infrastructure. The key challenge for Si photonic systems is the realization of compact, electrically driven optical gain elements. We review our recent developments in hybrid Si evanescent devices. We have demonstrated electrically pumped lasers, amplifiers, and photodetectors that can provide a low-cost, scalable solution for hybrid integration on a Si platform by using a novel hybrid waveguide architecture, consisting of III-V quantum wells bonded to Si waveguides.

  6. Hybrid Voltage-Multipliers Based Switching Power Converters

    Science.gov (United States)

    Rosas-Caro, Julio C.; Mayo-Maldonado, Jonathan C.; Vazquez-Bautista, Rene Fabian; Valderrabano-Gonzalez, Antonio; Salas-Cabrera, Ruben; Valdez-Resendiz, Jesus Elias

    2011-08-01

    This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft-Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.

  7. evaluation of striga-resistant early maize hybrids and test locations ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    to evaluate selected Striga-resistant maize (Zea mays L.) hybrids for grain yield and stability ... test locations possessed high discriminating ability. ... many inbred lines that combine earliness with ...... quality protein maize cultivars in stress and.

  8. Chaotic mixer improves microarray hybridization.

    Science.gov (United States)

    McQuain, Mark K; Seale, Kevin; Peek, Joel; Fisher, Timothy S; Levy, Shawn; Stremler, Mark A; Haselton, Frederick R

    2004-02-15

    Hybridization is an important aspect of microarray experimental design which influences array signal levels and the repeatability of data within an array and across different arrays. Current methods typically require 24h and use target inefficiently. In these studies, we compare hybridization signals obtained in conventional static hybridization, which depends on diffusional target delivery, with signals obtained in a dynamic hybridization chamber, which employs a fluid mixer based on chaotic advection theory to deliver targets across a conventional glass slide array. Microarrays were printed with a pattern of 102 identical probe spots containing a 65-mer oligonucleotide capture probe. Hybridization of a 725-bp fluorescently labeled target was used to measure average target hybridization levels, local signal-to-noise ratios, and array hybridization uniformity. Dynamic hybridization for 1h with 1 or 10ng of target DNA increased hybridization signal intensities approximately threefold over a 24-h static hybridization. Similarly, a 10- or 60-min dynamic hybridization of 10ng of target DNA increased hybridization signal intensities fourfold over a 24h static hybridization. In time course studies, static hybridization reached a maximum within 8 to 12h using either 1 or 10ng of target. In time course studies using the dynamic hybridization chamber, hybridization using 1ng of target increased to a maximum at 4h and that using 10ng of target did not vary over the time points tested. In comparison to static hybridization, dynamic hybridization reduced the signal-to-noise ratios threefold and reduced spot-to-spot variation twofold. Therefore, we conclude that dynamic hybridization based on a chaotic mixer design improves both the speed of hybridization and the maximum level of hybridization while increasing signal-to-noise ratios and reducing spot-to-spot variation.

  9. Simulation of a Hybrid Locomotion Robot Vehicle

    Science.gov (United States)

    Aarnio, P.

    2002-10-01

    This study describes a simulation process of a mobile robot. The focus is in kinematic and dynamic behavior simulations of hybrid locomotion robot vehicles. This research is motivated by the development needs of the WorkPartner field service robot. The whole robot system consists of a mobile platform and a two-hand manipulator. The robot platform, called Hybtor, is a hybrid locomotion robot capable of walking and driving by wheels as well as combining these two locomotion modes. This study describes first the general problems and their solutions in the dynamic simulation of mobile robots. A kinematic and dynamic virtual model of the Hybtor robot was built and simulations were carried out using one commercial simulation tool. Walking, wheel driven and rolking mode locomotion, which is a special hybrid locomotion style, has been simulated and analyzed. Position and force control issues during obstacle overrun and climbing were also studied.

  10. Portraits of colloidal hybrid nanostructures: controlled synthesis and potential applications.

    Science.gov (United States)

    Nguyen, Thanh-Dinh

    2013-03-01

    Inorganic hybrid nanostructures containing two or more nanocomponents have been emerging in many areas of materials science in recent years. The particle-particle interactions in a hybrid particle system could significantly improve existing local electronic structure and induce tunable physiochemical responses. The current work reviews the diverse inorganic hybrid nanostructures formed by adhesion of the different single components via seed-mediated method. The hybrid nanomaterials have great potentials for real applications in many other fields. The nanohybrids have been used as efficient heterocatalysts for carbon monoxide conversion and photodegradation of organic contaminants. The enhanced catalytic activity of these hybrid nanocatalysts could be attributed the formation of oxygen vacancies and electron transfer across the structural junction in a hybrid system as a result of the interfacial particle-particle interactions. The synergistic combination of up-converting and semiconducting properties in an up-converting semiconducting hybrid particle results in appearance of sub-band-gap photoconductivity. This behavior has a great significance for the design of photovoltaic devices for effective solar energy conversion. The functionalization and subsequent bioconjugation of the hybrid nanostructures to afford the multifunctional nanomedical platforms for simultaneous diagnosis and therapy are reviewed. The conjugated multifunctional hybrid nanostructures exhibit high biocompatibility and highly selective binding with functional groups-fabricated alive organs through delivering them to the tumor sites. The clever combinations of multifunctional features and antibody conjugation within these vehicles make them to generally offer new opportunities for clinical diagnostics and therapeutics.

  11. Effect of drought stress induced by polyethylene glycol (PEG) on ...

    African Journals Online (AJOL)

    Effect of drought stress induced by polyethylene glycol (PEG) on germination indices in corn ( Zea mays L.) hybrids. ... African Journal of Biotechnology ... and success in this stage is dependent on moisture content of soil at time of planting.

  12. Effects of Hybrid and Non-hybrid Epichloë Endophytes and Their Associated Host Genotypes on the Response of a Native Grass to Varying Environments.

    Science.gov (United States)

    Jia, Tong; Oberhofer, Martina; Shymanovich, Tatsiana; Faeth, Stanley H

    2016-07-01

    Asexual Epichloë endophytes are prevalent in cool season grasses, and many are of hybrid origin. Hybridization of asexual endophytes is thought to provide a rapid influx of genetic variation that may be adaptive to endophyte-host grass symbiota in stressful environments. For Arizona fescue (Festuca arizonica), hybrid symbiota are commonly found in resource-poor environments, whereas non-hybrid symbiota are more common in resource-rich environments. There have been very few experimental tests where infection, hybrid and non-hybrid status, and plant genotype have been controlled to tease apart their effects on host phenotype and fitness in different environments. We conducted a greenhouse experiment where hybrid (H) and non-hybrid (NH) endophytes were inoculated into plant genotypes that were originally uninfected (E-) or once infected with either the H or NH endophytes. Nine endophyte and plant genotypic group combinations were grown under low and high water and nutrient treatments. Inoculation with the resident H endophyte enhanced growth and altered allocation to roots and shoots, but these effects were greatest in resource-rich environments, contrary to expectations. We found no evidence of co-adaptation between endophyte species and their associated host genotypes. However, naturally E- plants performed better when inoculated with the hybrid endophyte, suggesting these plants were derived from H infected lineages. Our results show complex interactions between endophyte species of hybrid and non-hybrid origin with their host plant genotypes and environmental factors.

  13. Environmental effects on the hybrid glass fiber/carbon fiber composites

    Science.gov (United States)

    Tsai, Yun-I.

    2009-12-01

    Fiber reinforced polymer composites (FRPCs) have been widely used to replace conventional metals due to the high specific strength, fatigue resistance, and light weight. In the power distribution industry, an advanced composites rod has been developed to replace conventional steel cable as the load-bearing core of overhead conductors. Such conductors, called aluminum conductor composite core (ACCC) significantly increases the transmitting efficiency of existing power grid system without extensive rebuilding expenses, while meeting future demand for electricity. In general, the service life of such overhead conductors is required to be at least 30 years. Therefore, the long-term endurance of the composite core in various environments must be well-understood. Accelerated aging by hygrothermal exposure was conducted to determine the effect of moisture on the glass fiber (GF)/carbon fiber (CF) hybrid composites. The influence of water immersion and humid air exposure on mechanical properties is investigated. Results indicated that immersion in water is the most severe environment for such hybrid GF/CF composites, and results in greater saturation and degradation of properties. When immersed directly in water, the hybrid GF/CF composites exhibit a moisture uptake behavior that is more complex than composite materials reinforced with only one type of fiber. The unusual diffusion behavior is attributed to a higher packing density of fibers at the annular GF/CF interface, which acts as a temporary moisture barrier. Moisture uptake leads to the mechanical and thermal degradation of such hybrid GF/CF composites. Findings presented here indicate that the degradation is a function of exposure temperature, time, and moisture uptake level. Results also indicate that such hybrid GF/CF composites recover short beam shear (SBS) strength and glass transition temperature (Tg) values comparable to pre-aged samples after removal of the absorbed moisture. In the hygrothermal environment

  14. Hybrid polymer microspheres

    Science.gov (United States)

    Rembaum, A.

    1980-01-01

    Techniques have been successfully tested for bonding polymeric spheres, typically 0.1 micron in diameter, to spheres with diameter up to 100 microns. Hybrids are being developed as improved packing material for ion-exchange columns, filters, and separators.

  15. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  16. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  17. Functional hybrid materials

    National Research Council Canada - National Science Library

    Fahmi, Amir; Pietsch, Torsten; Mendoza, Cesar; Cheval, Nicolas

    2009-01-01

    .... This paper describes our group's achievements towards the development of multifunctional nanostructures via self-assembly of hybrid systems based on the block copolymer PS-b-P4VP and inorganic nanoparticles (NPs...

  18. Hybrid Rocket Technology

    Directory of Open Access Journals (Sweden)

    Sankaran Venugopal

    2011-04-01

    Full Text Available With their unique operational characteristics, hybrid rockets can potentially provide safer, lower-cost avenues for spacecraft and missiles than the current solid propellant and liquid propellant systems. Classical hybrids can be throttled for thrust tailoring, perform in-flight motor shutdown and restart. In classical hybrids, the fuel is stored in the form of a solid grain, requiring only half the feed system hardware of liquid bipropellant engines. The commonly used fuels are benign, nontoxic, and not hazardous to store and transport. Solid fuel grains are not highly susceptible to cracks, imperfections, and environmental temperature and are therefore safer to manufacture, store, transport, and use for launch. The status of development based on the experience of the last few decades indicating the maturity of the hybrid rocket technology is given in brief.Defence Science Journal, 2011, 61(3, pp.193-200, DOI:http://dx.doi.org/10.14429/dsj.61.518

  19. Nitrous Paraffin Hybrid Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nitrous Oxide Paraffin Hybrid engine (N2OP) is a proposed technology designed to provide small launch vehicles with high specific impulse, indefinitely storable...

  20. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.