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Sample records for chemo-mechanical coupling behaviour

  1. chemo-mechanical coupling in water unsaturated domains: capillary tension and crystallization pressure

    NASA Astrophysics Data System (ADS)

    Hulin, Claudie; Mercury, Lionel

    2015-04-01

    Unsaturated zones are widely present in natural systems, such as soils, deep aquifers and building stones under wetting-drying cycles. Such porous media contains the three phases liquid, gas and solid and present specific physico-chemical processes or properties - as soluble salts precipitation or capillary water properties rise - have important impact on environmental issues since they are coupled with mechanical effects. The driving force of both phase transitions and capillarization is the decreasing relative humidity below the saturated value in the atmospheric air contacting the unsaturated materials. - Decreasing relative humidity leads to evaporation, creating local supersaturation and then driving crystallization. According to the usual theory of crystallization pressure, a confined growing crystal can exert a constraint against the pore wall, leading to its rupture if it exceeds the tensile strength of the pore material. This coupled chemo-mechanical process requires a nano-scale film of solution to hold between the crystal and the pore, which allows the solutes to diffuse and the solution not to precipitate despite increasing supersaturation. The repulsive effect between growing and host solids, ultimately increases the local pressure and may induce the host rupture - Capillarity has a large occurrence in unsaturated porous media and depends on pore radius and relative humidity of air. The capillary state makes the internal pressure of capillary water can drop down to negative values, meaning it is under tensile state and potentially exert traction on pore wall. These effects of chemo-mechanical coupling are observed using an experimental approach on three simplified natural analogues: porous membrane, borosilicate microcapillaries, and synthetic fluid inclusions. In the two former samples, sodium sulfates precipitates are induced through wetting-drying cycles and the role of both the capillarity and the crystallization pressure are observed. In the

  2. The nonlinear chemo-mechanic coupled dynamics of the F 1 -ATPase molecular motor.

    PubMed

    Xu, Lizhong; Liu, Fang

    2012-03-01

    The ATP synthase consists of two opposing rotary motors, F0 and F1, coupled to each other. When the F1 motor is not coupled to the F0 motor, it can work in the direction hydrolyzing ATP, as a nanomotor called F1-ATPase. It has been reported that the stiffness of the protein varies nonlinearly with increasing load. The nonlinearity has an important effect on the rotating rate of the F1-ATPase. Here, considering the nonlinearity of the γ shaft stiffness for the F1-ATPase, a nonlinear chemo-mechanical coupled dynamic model of F1 motor is proposed. Nonlinear vibration frequencies of the γ shaft and their changes along with the system parameters are investigated. The nonlinear stochastic response of the elastic γ shaft to thermal excitation is analyzed. The results show that the stiffness nonlinearity of the γ shaft causes an increase of the vibration frequency for the F1 motor, which increases the motor's rotation rate. When the concentration of ATP is relatively high and the load torque is small, the effects of the stiffness nonlinearity on the rotating rates of the F1 motor are obvious and should be considered. These results are useful for improving calculation of the rotating rate for the F1 motor and provide insight about the stochastic wave mechanics of F1-ATPase.

  3. Experimental evidence for chemo-mechanical coupling during carbon mineralization in ultramafic rocks

    NASA Astrophysics Data System (ADS)

    Lisabeth, H. P.; Zhu, W.; Kelemen, P. B.; Ilgen, A.

    2017-09-01

    Storing carbon dioxide in the subsurface as carbonate minerals has the benefit of long-term stability and immobility. Ultramafic rock formations have been suggested as a potential reservoir for this type of storage due to the availability of cations to react with dissolved carbon dioxide and the fast reaction rates associated with minerals common in ultramafic formations; however, the rapid reactions have the potential to couple with the mechanical and hydraulic behavior of the rocks and little is known about the extent and mechanisms of this coupling. In this study, we argue that the dissolution of primary minerals and the precipitation of secondary minerals along pre-existing fractures in samples lead to reductions in both the apparent Young's modulus and shear strength of aggregates, accompanied by reduction in permeability. Hydrostatic and triaxial deformation experiments were run on dunite samples saturated with de-ionized water and carbon dioxide-rich solutions while stress, strain, permeability and pore fluid chemistry were monitored. Sample microstructures were examined after reaction and deformation using scanning electron microscopy (SEM). The results show that channelized dissolution and carbonate mineral precipitation in the samples saturated with carbon dioxide-rich solutions modify the structure of grain boundaries, leading to the observed reductions in stiffness, strength and permeability. A geochemical model was run to help interpret fluid chemical data, and we find that the apparent reaction rates in our experiments are faster than rates calculated from powder reactors, suggesting mechanically enhanced reaction rates. In conclusion, we find that chemo-mechanical coupling during carbon mineralization in dunites leads to substantial modification of mechanical and hydraulic behavior that needs to be accounted for in future modeling efforts of in situ carbon mineralization projects.

  4. Modelling and simulations of the chemo-mechanical behaviour of leached cement-based materials: Interactions between damage and leaching

    SciTech Connect

    Stora, E.; Bary, B.; Deville, E.; Montarnal, P.

    2010-08-15

    The assessment of the durability of cement-based materials, which could be employed in underground structures for nuclear waste disposal, requires accounting for deterioration factors, such as chemical attacks and damage, and for the interactions between these phenomena. The objective of the present paper consists in investigating the long-term behaviour of cementitious materials by simulating their response to chemical and mechanical solicitations. In a companion paper (Stora et al., submitted to Cem. Concr. Res. 2008), the implementation of a multi-scale homogenization model into an integration platform has allowed for evaluating the evolution of the mineral composition, diffusive and elastic properties inside a concrete material subjected to leaching. To complete this previous work, an orthotropic micromechanical damage model is presently developed and incorporated in this numerical platform to estimate the mechanical and diffusive properties of damaged cement-based materials. Simulations of the chemo-mechanical behaviour of leached cementitious materials are performed with the tool thus obtained and compared with available experiments. The numerical results are insightful about the interactions between damage and chemical deteriorations.

  5. Time-dependent Deformation in Porous Rocks Driven by Chemo-mechanical Coupling

    NASA Astrophysics Data System (ADS)

    Meredith, P. G.; Brantut, N.; Heap, M. J.; Baud, P.

    2015-12-01

    We report results from triaxial deformation of porous sandstone and limestone conducted to determine the time-dependency of deformation. Experiments were run on water-saturated samples under constant differential stress (creep) conditions. In sandstone, the deformation is entirely brittle for all levels of stress and for all resulting strain rates. The strain rate during creep is very stress sensitive, with a change of only 20 MPa in differential stress producing three orders of magnitude change in strain rate. Failure occurs by localized shear faulting after an extended period of dilatant microcracking, as evidenced by the output of acoustic emissions. By contrast, the behaviour of limestone is more complex. At low effective pressure, the creep behavior is brittle and characterised by the same features as observed for sandstone; a decelerating phase of creep, followed by an inflection and then an accelerating creep phase leading to macroscopic failure. Similarly, only a small amount of inelastic strain is accommodated before failure, and P wave speeds measured throughout deformation decrease continuously, indicating a continuous increase in dilatant crack damage. At higher effective pressure, brittle creep still occurs, but the details of the time-dependent deformation behavior are quite different. First, the total amount of accumulated creep strain increases dramatically with decreasing strain rate, and no localized failure occurs even at these higher strains. Second, the rate of decrease in P wave speeds during deformation decreases with decreasing strain rate; indicating that less damage is accumulated per unit strain when the strain rate is lower. Third, complementary strain rate stepping experiments indicate that the deformation becomes more compactant at lower strain rates. Taken together, these observations suggest that rate-dependent compactive deformation mechanisms compete with dilatant subcritical crack growth during creep in limestone under low

  6. Investigation of the chemo-mechanical coupling in lithiation/delithiation of amorphous Si through simulations of Si thin films and Si nanospheres

    NASA Astrophysics Data System (ADS)

    Wang, Miao; Xiao, Xinran

    2016-09-01

    A strong asymmetric rate behavior between lithiation and delithiation has been observed in amorphous Si (a-Si) anode in the form of thin films, but not in other geometries, such as Si nanospheres. This work investigated the rate behavior of the two geometries through numerical simulations. The results reveal that the rate behavior is affected by the geometry and the constraint of the electrode, the chemo-mechanical coupling, and the prior process. A substrate-constrained film has a relatively low surface/volume ratio and a constant surface area. Its lithiation has a great tendency to be hindered by surface limitation. The chemo-mechanical coupling also plays an important role. The stress profiles differ in the two geometries but both affect the lithiation process more than the delithiation process. The overall delithiation capacity is affected very little by the chemo-mechanical coupling. In cyclic loading, the delithiation capacity is reduced at the same rate as the lithiation capacity because of the low initial state of charge in the electrode. The asymmetric rate behavior was absent under cyclic loading. On the other hand, a slow charging process resulted in a better retained delithiation capacity and an asymmetric rate behavior at higher rates.

  7. A three-dimensional chemo-mechanical continuum model for smooth muscle contraction.

    PubMed

    Böl, Markus; Schmitz, André; Nowak, Götz; Siebert, Tobias

    2012-09-01

    Based on two fields, namely the placement and the calcium concentration, a chemo-mechanically coupled three-dimensional model, describing the contractile behaviour of smooth muscles, is presented by means of a strain energy function. The strain energy function (Schmitz and Böl, 2011) is additively decomposed into a passive part, relating to elastin and collagen, and an active calcium-driven part related to the chemical contraction of the smooth muscle cells. For the description of the calcium phase the four state cross-bridge model of Hai and Murphy (Hai and Murphy, 1988) has been implemented into the finite element method. Beside three-dimensional illustrative boundary-value problems demonstrating the features of the presented modelling concept, simulations on an idealised artery document the applicability of the model to more realistic geometries.

  8. Papain gel: a new chemo-mechanical caries removal agent.

    PubMed

    Bussadori, Sandra Kalil; Castro, Laura Camacho; Galvão, Ana Claudia

    2005-01-01

    The chemo-mechanical caries removal method has been a solution for treatment of patients seeking alternatives to conventional methods. Among different kinds of chemo-mechanical caries removal systems, Papacarie--a papain gel--was found to be easy to manipulate, simple and cheap, as well as effective in removing infected tissues.

  9. Tumour angiogenesis as a chemo-mechanical surface instability

    PubMed Central

    Giverso, Chiara; Ciarletta, Pasquale

    2016-01-01

    The hypoxic conditions within avascular solid tumours may trigger the secretion of chemical factors, which diffuse to the nearby vasculature and promote the formation of new vessels eventually joining the tumour. Mathematical models of this process, known as tumour angiogenesis, have mainly investigated the formation of the new capillary networks using reaction-diffusion equations. Since angiogenesis involves the growth dynamics of the endothelial cells sprouting, we propose in this work an alternative mechanistic approach, developing a surface growth model for studying capillary formation and network dynamics. The model takes into account the proliferation of endothelial cells on the pre-existing capillary surface, coupled with the bulk diffusion of the vascular endothelial growth factor (VEGF). The thermo-dynamical consistency is imposed by means of interfacial and bulk balance laws. Finite element simulations show that both the morphology and the dynamics of the sprouting vessels are controlled by the bulk diffusion of VEGF and the chemo-mechanical and geometric properties at the capillary interface. Similarly to dendritic growth processes, we suggest that the emergence of tree-like vessel structures during tumour angiogenesis may result from the free boundary instability driven by competition between chemical and mechanical phenomena occurring at different length-scales. PMID:26948692

  10. Bio-chemo-mechanical models for nuclear deformation in adherent eukaryotic cells.

    PubMed

    Nava, Michele M; Raimondi, Manuela T; Pietrabissa, Riccardo

    2014-10-01

    Adherent eukaryotic cells are subjected to a broad variety of extracellular and intracellular stimuli regulating their behaviour. These stimuli can be either purely chemical, for example soluble factors binding to the cell membrane, or mechano-chemical, for example integrin-based adhesion complexes stretching the cell cytoskeleton. Here, we focus on mechano-chemical stimuli such as extracellular forces (interstitial flow, pressurization) and intracellular forces (due to cell adhesion), which may combine generating stress-strain states in the cytoskeleton. These states are transferred to the nucleus to influence the transcription of specific genes, likely by changing the chromatin organization and by altering the permeability of the nuclear membrane. While there exists increasing experimental evidence of the mechanosensing role of the cell nucleus, both the underlying molecular mechanisms involved, and the nuclear structural behaviour in response to forces, are still poorly understood. Here, we review the existing literature on computational models developed to investigate the chemo-mechanical behaviour of adherent eukaryotic cells. We analyse two main classes of models of single-cell mechanics, based either on the discrete or on the continuum approaches. We focus on the bio-chemo-mechanical model and modelling techniques accounting for the nuclear body. The modelling techniques are discussed highlighting their ability in predicting cytoskeletal contractility states and nuclear stress-strain states.

  11. A programmable soft chemo-mechanical actuator exploiting a catalyzed photochemical water-oxidation reaction.

    PubMed

    Yuan, P; McCracken, J M; Gross, D E; Braun, P V; Moore, J S; Nuzzo, R G

    2017-10-04

    We describe a composite hydrogel containing an embedding coupled chemistry for light-sensitized catalytic reactions that enables chemo-mechanical actuation of poly(acrylic acid)-based gels. In these materials, a photosensitizer and catalyst-ruthenium trisbipyridine and iridium dioxide nanoparticles, respectively-are incorporated into the hydrogel where together, with visible light irradiation, they undergo a catalytic water-oxidation reaction that lowers the pH and induces a dissipative/chemically-driven strain change in the gel. To demonstrate the capacity for 3D chemo-mechanical actuation, a layer of non-pH responsive poly(2-hydroxyethyl methacrylate) is added to the photo-active composite gel to create a model bimorph actuator. Triggering and terminating the water-oxidation reaction leads to a programmatic expansion and contraction of the active layer, which induces different modes of biomimetic curling motions in the bimorph actuator in light and dark environments. The efficiency of this system is fundamentally limited by the system-level design, which provides no capacity to sustain a local pH gradient against diffusive mixing. Even so, if the initial pH of the background solution is reestablished either actively or passively between each reaction cycle, it is possible to realize multiple cycles of reversible actuation. We describe a thermodynamic analysis of this system which identifies specific features mediating efficiency losses and conceptual requirements for mesoscopic design rules for optimization of this system and for advancing soft actuation systems in general.

  12. Bio-Chemo-Mechanical Models of Vascular Mechanics.

    PubMed

    Kim, Jungsil; Wagenseil, Jessica E

    2015-07-01

    Models of vascular mechanics are necessary to predict the response of an artery under a variety of loads, for complex geometries, and in pathological adaptation. Classic constitutive models for arteries are phenomenological and the fitted parameters are not associated with physical components of the wall. Recently, microstructurally-linked models have been developed that associate structural information about the wall components with tissue-level mechanics. Microstructurally-linked models are useful for correlating changes in specific components with pathological outcomes, so that targeted treatments may be developed to prevent or reverse the physical changes. However, most treatments, and many causes, of vascular disease have chemical components. Chemical signaling within cells, between cells, and between cells and matrix constituents affects the biology and mechanics of the arterial wall in the short- and long-term. Hence, bio-chemo-mechanical models that include chemical signaling are critical for robust models of vascular mechanics. This review summarizes bio-mechanical and bio-chemo-mechanical models with a focus on large elastic arteries. We provide applications of these models and challenges for future work.

  13. Bio-chemo-mechanical models of vascular mechanics

    PubMed Central

    Kim, Jungsil; Wagenseil, Jessica E.

    2014-01-01

    Models of vascular mechanics are necessary to predict the response of an artery under a variety of loads, for complex geometries, and in pathological adaptation. Classic constitutive models for arteries are phenomenological and the fitted parameters are not associated with physical components of the wall. Recently, microstructurally-linked models have been developed that associate structural information about the wall components with tissue-level mechanics. Microstructurally-linked models are useful for correlating changes in specific components with pathological outcomes, so that targeted treatments may be developed to prevent or reverse the physical changes. However, most treatments, and many causes, of vascular disease have chemical components. Chemical signaling within cells, between cells, and between cells and matrix constituents affects the biology and mechanics of the arterial wall in the short- and long-term. Hence, bio-chemo-mechanical models that include chemical signaling are critical for robust models of vascular mechanics. This review summarizes bio-mechanical and bio-chemo-mechanical models with a focus on large elastic arteries. We provide applications of these models and challenges for future work. PMID:25465618

  14. Chemo-mechanical control of neural stem cell differentiation

    NASA Astrophysics Data System (ADS)

    Geishecker, Emily R.

    Cellular processes such as adhesion, proliferation, and differentiation are controlled in part by cell interactions with the microenvironment. Cells can sense and respond to a variety of stimuli, including soluble and insoluble factors (such as proteins and small molecules) and externally applied mechanical stresses. Mechanical properties of the environment, such as substrate stiffness, have also been suggested to play an important role in cell processes. The roles of both biochemical and mechanical signaling in fate modification of stem cells have been explored independently. However, very few studies have been performed to study well-controlled chemo-mechanotransduction. The objective of this work is to design, synthesize, and characterize a chemo-mechanical substrate to encourage neuronal differentiation of C17.2 neural stem cells. In Chapter 2, Polyacrylamide (PA) gels of varying stiffnesses are functionalized with differing amounts of whole collagen to investigate the role of protein concentration in combination with substrate stiffness. As expected, neurons on the softest substrate were more in number and neuronal morphology than those on stiffer substrates. Neurons appeared locally aligned with an expansive network of neurites. Additional experiments would allow for statistical analysis to determine if and how collagen density impacts C17.2 differentiation in combination with substrate stiffness. Due to difficulties associated with whole protein approaches, a similar platform was developed using mixed adhesive peptides, derived from fibronectin and laminin, and is presented in Chapter 3. The matrix elasticity and peptide concentration can be individually modulated to systematically probe the effects of chemo-mechanical signaling on differentiation of C17.2 cells. Polyacrylamide gel stiffness was confirmed using rheological techniques and found to support values published by Yeung et al. [1]. Cellular growth and differentiation were assessed by cell counts

  15. Experimental investigations for the modeling of chemo-mechanical processes of anhydritic rock

    NASA Astrophysics Data System (ADS)

    Huber, Tara; Pimentel, Erich; Anagnostou, Georg

    2015-04-01

    When anhydritic rock comes into contact with water, the anhydrite dissolves and gypsum precipitates as a result of an oversaturation of the sulphate and calcium ions in the water. This anhydrite to gypsum transformation (AGT) leads to an increase in the solid volume by roughly 61% and possibly also of the pore volume, thus resulting in macroscopic swelling. In tunneling, swelling rock can cause massive damage, since it can exhibit high pressures on the lining or result in large deformations of the lining. Even though this phenomenon has already been observed more than a century ago, AGT in sulphatic rock still raises many open questions. One question we focus on is the mechanical (i.e. stress, strain) behavior of anhydritic rock during swelling. The coupled chemo-mechanical processes, i.e. the development of stresses and strains during AGT, has not been fully understood so far. A chemo-mechanical model must be considered which take anhydrite dissolution, gypsum precipitation as well as stresses and strains into account. In this contribution we present some fundamental research which was done in order to establish a relationship between AGT and the resulting or applied strains and stresses. The research contains experiments on samples consisting of anhydrite and kaolin under oedometric conditions. In order to reduce uncertainties due to swelling of clay as well as inhomogeneous compositions and structures of the natural rock samples, the experiments at the present stage of this research are performed on artificially created, reproducible samples. The samples contain 40% industrial anhydritic powder and 60% Polwhite E Chinaclay (of which the main component is kaolinite). The powders are mixed and compacted in a steel ring under high axial pressure, thus creating intact discs with a dry density of roughly 1.9 g/cm3. In a first series of Oedometer tests the swelling strain under various constant axial stress is measured until the maximal strain is reached. At the

  16. One-Pot dry chemo-mechanical deconstruction for bioethanol production from sugarcane bagasse.

    PubMed

    Sambusiti, C; Licari, A; Solhy, A; Aboulkas, A; Cacciaguerra, T; Barakat, A

    2015-04-01

    The aim of this study was the application of an innovative dry chemo-mechanical pretreatment using different mechanical stresses to produce bioethanol from sugarcane bagasse (SB). The effect of different milling methods on physicochemical composition, enzymatic hydrolysis, bioethanol production and energy efficiency was also evaluated. SB was pretreated with NaOH and H3PO4 at high materials concentration (5 kg/L). Results indicate that vibratory milling (VBM) was more effective in the reduction of particles size and cellulose crystallinity compared to centrifugal (CM) and ball (BM) milling. NaOH pretreatment coupling to BM and VBM was preferred to enhance glucose yields and bioethanol production, while CM consumed less energy compared to BM and VBM. Moreover, the highest energy efficiency (η=0.116 kg glucose/kWh) was obtained with NaOH-CM. Therefore, the combination of dry NaOH and CM appears the most suitable and interesting pretreatment for the production of bioethanol from SB. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Progressive fracture in quartzite samples as a result of chemo-mechanical interactions

    NASA Astrophysics Data System (ADS)

    Voigtlaender, Anne; Leith, Kerry; Krautblatter, Michael

    2017-04-01

    Stress corrosion cracking reduces brittle fracture strength through the interaction of chemical and mechanical processes. In order to better understand the coupling of these processes in natural rock samples, we set up a long-term test in which six Alta-Quartzite samples (AQ 1-6, 300 x 30 x 70 mm) were brought to failure in stepped single edge notch bending (SENB) creep tests. Distilled water was introduced to the notch in four of these samples (AQ 1-2, 4-5), while reference samples remained dry. Samples were pre-loaded to 60% of their intact strength, as determined from preliminary short-term tests, to generate sharp initial cracks at the end of the saw-cut notch. They were then unloaded, before being re-loaded in steps of 5-10 % of the intact flexural strength starting at 0% for AQ1-3 and at 50% for AQ4-6. Strains were measured using electrical resistivity strain gages 2 mm below the notch. For comparable loading paths, measured strains were up to an order of magnitude higher in samples which had water introduced, and approached tertiary creep at 70-80% of the dry maximum load. Scanning electron microscopy of the fracture path of the 'wet notch' quartzite samples revealed various alterations in conformity with the stress field. Observations include etch pits aligned parallel to the principal stress direction, terrace dissolution in the plane of the principal tensile stress, as well as stress direction dependent contrast of highly to not corroded surface, following microstructural, e.g. foliation planes. These fracture features indicate the importance of coupled chemical and mechanical processes, particularly along grain boundaries, crystal planes and microstructural interfaces. Chemo-mechanical interactions are likely to facilitate progressive fracture of surface bedrocks in natural setting. Stress corrosion cracking is thus an important control on the promotion of rock slope failure, bedrock incision and building material damage.

  18. A Numerical Hydro-Chemo-Mechanical Model for Fault Activation under Reactive Fluid Flow

    NASA Astrophysics Data System (ADS)

    Pouya, A.; Tounsi, H.; Rohmer, J.

    2015-12-01

    The migration of CO2-rich fluid in fractured rock masses can cause processes such as mineral dissolution and precipitation, chemically induced weakening, which can affect the long-term mechanical and transport properties of the rock mass as well as the stability of fault systems. Some numerical approaches are already available in the literature for modelling the dissolution/precipitation phenomena in fractures (e.g. Yasuhara & Elsworth 2007) as well as subcritical crack propagation (e.g. Park et al. 2007). Generally, the dissolution is supposed to increase the rock porosity and, in this way, decrease the rock strength. Some experimental data are available for the variation of rock strength and stiffness parameters with the porosity and so as a consequence of dissolution process (Bemer et al. 2004). Also the effect of chemical processes on the mechanical stability has been studied and modelled numerically in the framework of continuum materials and the context, in particular, of weathering in underground galleries (Ghabezloo & Pouya 2006). In the context of fault systems, a complete numerical modelling of the stability evolution with the flow of a reactive fluid has not yet been done. In this paper we present a simplified, but complete, set of equations for a whole system of coupled hydro-chemo-mechanical process of reactive fluid flow inside a fault. These equations have been implemented in Porofis, a FEM numerical code specially conceived for HCM processes in porous fractured media. We show how this numerical method allows to model the coupled HCM processes in the fault and the evolution of the mechanical stability in presence of in situ stresses and reactive fluid flow.

  19. Chemo-mechanical modeling of tumor growth in elastic epithelial tissue

    NASA Astrophysics Data System (ADS)

    Bratsun, Dmitry A.; Zakharov, Andrey P.; Pismen, Len

    2016-08-01

    We propose a multiscale chemo-mechanical model of the cancer tumor development in the epithelial tissue. The epithelium is represented by an elastic 2D array of polygonal cells with its own gene regulation dynamics. The model allows the simulation of the evolution of multiple cells interacting via the chemical signaling or mechanically induced strain. The algorithm includes the division and intercalation of cells as well as the transformation of normal cells into a cancerous state triggered by a local failure of the spatial synchronization of the cellular rhythms driven by transcription/translation processes. Both deterministic and stochastic descriptions of the system are given for chemical signaling. The transformation of cells means the modification of their respective parameters responsible for chemo-mechanical interactions. The simulations reproduce a distinct behavior of invasive and localized carcinoma. Generally, the model is designed in such a way that it can be readily modified to take account of any newly understood gene regulation processes and feedback mechanisms affecting chemo-mechanical properties of cells.

  20. Chemo-mechanical modeling of tumor growth in elastic epithelial tissue

    SciTech Connect

    Bratsun, Dmitry A.; Zakharov, Andrey P.; Pismen, Len

    2016-08-02

    We propose a multiscale chemo-mechanical model of the cancer tumor development in the epithelial tissue. The epithelium is represented by an elastic 2D array of polygonal cells with its own gene regulation dynamics. The model allows the simulation of the evolution of multiple cells interacting via the chemical signaling or mechanically induced strain. The algorithm includes the division and intercalation of cells as well as the transformation of normal cells into a cancerous state triggered by a local failure of the spatial synchronization of the cellular rhythms driven by transcription/translation processes. Both deterministic and stochastic descriptions of the system are given for chemical signaling. The transformation of cells means the modification of their respective parameters responsible for chemo-mechanical interactions. The simulations reproduce a distinct behavior of invasive and localized carcinoma. Generally, the model is designed in such a way that it can be readily modified to take account of any newly understood gene regulation processes and feedback mechanisms affecting chemo-mechanical properties of cells.

  1. Impact of Hydrogel Structure and Composition on Autonomic Chemo-Mechanical Behavior

    NASA Astrophysics Data System (ADS)

    Kramb, Ryan; Buskohl, Philip; Vaia, Richard

    2014-03-01

    Autonomic materials harvest energy to change size, shape, or color in response to a set of environmental conditions. At the core of this biomimetic behavior is a material that transduces energy between forms (e.g. chemical to mechanical). The most widely studied of these materials are self-oscillating, Ru-containing PNIPAAm hydrogels driven by the Belousov -Zhabotinsky (BZ) reaction; and if correctly designed, BZ gels mimic biological process such as a quorum sensing or beating like a heart. However, establishing relationships between chemo-mechanical response and gel characteristics, such as crosslinking density, monomer composition, catalyst content, and gel stiffness, has remained elusive due to the limited material set and challenges in determining the appropriate balance of reaction kinetics and mechanical response necessary to establish self-sustaining oscillations. To address this challenge, we have broadened the suite of available monomers through a modular synthesis of the Ru-containing constituent; and thereby demonstrating facile tuning of the aforementioned characteristics of the BZ gel. From the resulting correlations between gel properties and chemo-mechanical response, we discuss the material design of composite autonomic gels for maximum shape change, directionality of oscillations, and synchronization of oscillations analogous to a natural pacemaker cell cluster.

  2. Randomized controlled clinical trial of long-term chemo-mechanical caries removal using Papacarie™ gel.

    PubMed

    Motta, Lara Jansiski; Bussadori, Sandra Kalil; Campanelli, Ana Paula; Silva, André Luis da; Alfaya, Thays Almeida; Godoy, Camila Haddad Leal de; Navarro, Maria Fidela de Lima

    2014-01-01

    Compare the effectiveness of Papacarie™ gel for the chemo-mechanical removal of carious lesions on primary teeth to conventional caries removal with a low-speed bur with regard to execution time, clinical aspects and radiographic findings. A randomized controlled clinical trial with a split-mouth design was carried out. The sample was composed of 20 children aged four to seven years, in whom 40 deciduous teeth were randomly divided into two groups: chemo-mechanical caries removal with Papacarie™ and removal of carious dentin with a low-speed bur. Each child underwent both procedures and served as his/her own control. Restorations were performed with glass ionomer cement. The time required to perform the procedure was also analyzed. The patients underwent longitudinal clinical and radiographic follow-up of the restorations. No statistically significant difference between groups was found regarding the time required to perform the procedures and the radiographic follow up. Statistically significant differences between groups were found in the clinical evaluation at 6 and 18 months after treatment. Papacarie™ is as effective as the traditional method for the removal of carious dentin on deciduous teeth, but offers the advantages of the preservation of sound dental tissue as well as the avoidance of sharp rotary instruments and local anesthesia.

  3. Single-Molecule Chemo-Mechanical Spectroscopy Provides Structural Identity of Folding Intermediates

    PubMed Central

    Motlagh, Hesam N.; Toptygin, Dmitri; Kaiser, Christian M.; Hilser, Vincent J.

    2016-01-01

    Single-molecule force spectroscopy has emerged as a powerful tool for studying the folding of biological macromolecules. Mechanical manipulation has revealed a wealth of mechanistic information on transient and intermediate states. To date, the majority of state assignment of intermediates has relied on empirical demarcation. However, performing such experiments in the presence of different osmolytes provides an alternative approach that reports on the structural properties of intermediates. Here, we analyze the folding and unfolding of T4 lysozyme with optical tweezers under a chemo-mechanical perturbation by adding osmolytes. We find that two unrelated protective osmolytes, sorbitol and trimethylamine-n-oxide, function by marginally decelerating unfolding rates and specifically modulating early events in the folding process, stabilizing formation of an on-pathway intermediate. The chemo-mechanical perturbation provides access to two independent metrics of the relevant states during folding trajectories, the contour length, and the solvent-accessible surface area. We demonstrate that the dependence of the population of the intermediate in different osmolytes, in conjunction with its measured contour length, provides the ability to discriminate between potential structural models of intermediate states. Our study represents a general strategy that may be employed in the structural modeling of equilibrium intermediate states observed in single-molecule experiments. PMID:27028638

  4. Analytical process design for chemo-mechanical polishing of glass aspheres

    NASA Astrophysics Data System (ADS)

    Waechter, Daniel; Dambon, Olaf; Klocke, Fritz

    2011-09-01

    This work deals with the chemo-mechanical sub-aperture polishing of glass lenses using spiral tool path and pressure-inflated membrane tools. Current trends in manufacturing precision optics in Europe go to smaller lot sizes and an increasing ratio of custom specific lens design. This requires deterministic processes as well as methods for an analytical process set-up without empirical try-outs. Chemo-mechanical polishing is typically applied for pre-polishing step, which aims for smoothing the surface with moderate shape correction. But due to kinematic effects the spiral-polishing process often shows changes in the radius of curvature, which are right now corrected by empirical try-outs and iterative corrections. This paper suggests an analytical tool for the compensation of these effects and contributes doing so to an efficient pre-polishing of aspheres. A mathematical model calculates the local distribution of material removal. It is based on Preston's equation and takes into account the influence of the major input parameters, such as feed rate, spindle revolutions and spot size. The given results show a significant reduction in shape deviation applying this methods compared to a polishing process without any compensation.

  5. Differences between micro-hardness affected dentin after mechanical or chemo-mechanical infected dentin disposal (laboratory experiment)

    NASA Astrophysics Data System (ADS)

    Ihsani, V.; Nursasongko, B.; Djauharie, N.

    2017-08-01

    The concept of conserving healthy tooth structures during cavity preparation has gained popularity with chemo-mechanical caries removal. This study compared three methods of caries removal using: a chemo-mechanical caries removal papain gel; Papacarie® (these contain natural ingredients, mainly papain enzyme); and mechanical preparation with a bur rotary instrument. The purpose of this study was to compare affected dentin micro-hardness after removal of infected dentin with mechanical and chemo-mechanical techniques. Twenty-seven permanent molar teeth were randomly divided into three groups receiving removal of infected dentin. These were: Group 1: chemo-mechanical technique using papain gel; Group 2: chemo-mechanical technique using Papacarie® Group 3: mechanical technique using a bur rotary instrument. Each group was tested using Knoop Micro-hardness tester, and the data were submitted to one way ANOVA and Post-hoc Tukey test. There is a significant difference between Groups 1 and 3, and Groups 2 and 3, p = 0.000. However, there is no significant difference between Groups 1 and 2, p = 1.000. Affected dentin micro-hardness after removal of infected dentin with a bur rotary tool is higher than after use of the papain gel or Papacarie®. Affected dentin micro-hardness after removal of infected dentin with Papacarie® and papain gel give almost the same result.

  6. Chemo-mechanical removal of caries in an adolescent patient using a papain gel: case report.

    PubMed

    Bussadori, S K; Guedes, C C; Hermida Bruno, M L; Ram, D

    2008-01-01

    The chemo-mechanical model of caries removal has been introduced as an alternative method of caries removal and is indicated to overcome the inconvenience of using burs and local anesthesia, causing less discomfort to the patient, and preserving healthy dental structure. Papacarie is a papain gel composed basically of papain, chloramines, and toluidine blue. Papain interacts with exposed collagen by the dissolution of dentin minerals through bacteria, making the infected dentin softer, and allowing its removal with non-cutting instruments without local anesthesia and burs. This paper proposes the use of a papain-based gel for the removal of active caries with infected tissue followed by a glass ionomer restoration in an adolescent patient. Removal of caries tissue with Papacarie proved to be efficient, easy and comfortable for the patient.

  7. The chemo-mechanical effect of cutting fluid on material removal in diamond scribing of silicon

    NASA Astrophysics Data System (ADS)

    Kumar, Arkadeep; Melkote, Shreyes N.

    2017-07-01

    The mechanical integrity of silicon wafers cut by diamond wire sawing depends on the damage (e.g., micro-cracks) caused by the cutting process. The damage type and extent depends on the material removal mode, i.e., ductile or brittle. This paper investigates the effect of cutting fluid on the mode of material removal in diamond scribing of single crystal silicon, which simulates the material removal process in diamond wire sawing of silicon wafers. We conducted scribing experiments with a diamond tipped indenter in the absence (dry) and in the presence of a water-based cutting fluid. We found that the cutting mode is more ductile when scribing in the presence of cutting fluid compared to dry scribing. We explain the experimental observations by the chemo-mechanical effect of the cutting fluid on silicon, which lowers its hardness and promotes ductile mode material removal.

  8. A chemo-mechanical free-energy-based approach to model durotaxis and extracellular stiffness-dependent contraction and polarization of cells.

    PubMed

    Shenoy, Vivek B; Wang, Hailong; Wang, Xiao

    2016-02-06

    We propose a chemo-mechanical model based on stress-dependent recruitment of myosin motors to describe how the contractility, polarization and strain in cells vary with the stiffness of their surroundings and their shape. A contractility tensor, which depends on the distribution of myosin motors, is introduced to describe the chemical free energy of the cell due to myosin recruitment. We explicitly include the contributions to the free energy that arise from mechanosensitive signalling pathways (such as the SFX, Rho-Rock and MLCK pathways) through chemo-mechanical coupling parameters. Taking the variations of the total free energy, which consists of the chemical and mechanical components, in accordance with the second law of thermodynamics provides equations for the temporal evolution of the active stress and the contractility tensor. Following this approach, we are able to recover the well-known Hill relation for active stresses, based on the fundamental principles of irreversible thermodynamics rather than phenomenology. We have numerically implemented our free energy-based approach to model spatial distribution of strain and contractility in (i) cells supported by flexible microposts, (ii) cells on two-dimensional substrates, and (iii) cells in three-dimensional matrices. We demonstrate how the polarization of the cells and the orientation of stress fibres can be deduced from the eigenvalues and eigenvectors of the contractility tensor. Our calculations suggest that the chemical free energy of the cell decreases with the stiffness of the extracellular environment as the cytoskeleton polarizes in response to stress-dependent recruitment of molecular motors. The mechanical energy, which includes the strain energy and motor potential energy, however, increases with stiffness, but the overall energy is lower for cells in stiffer environments. This provides a thermodynamic basis for durotaxis, whereby cells preferentially migrate towards stiffer regions of the

  9. Simulating uterine contraction by using an electro-chemo-mechanical model.

    PubMed

    Sharifimajd, Babak; Thore, Carl-Johan; Stålhand, Jonas

    2016-06-01

    Contractions of uterine smooth muscle cells consist of a chain of physiological processes. These contractions provide the required force to expel the fetus from the uterus. The inclusion of these physiological processes is, therefore, imperative when studying uterine contractions. In this study, an electro-chemo-mechanical model to replicate the excitation, activation, and contraction of uterine smooth muscle cells is developed. The presented modeling strategy enables efficient integration of knowledge about physiological processes at the cellular level to the organ level. The model is implemented in a three-dimensional finite element setting to simulate uterus contraction during labor in response to electrical discharges generated by pacemaker cells and propagated within the myometrium via gap junctions. Important clinical factors, such as uterine electrical activity and intrauterine pressure, are predicted using this simulation. The predictions are in agreement with clinically measured data reported in the literature. A parameter study is also carried out to investigate the impact of physiologically related parameters on the uterine contractility.

  10. Chemo-Mechanical Characteristics of Mud Formed from Environmental Dust Particles in Humid Ambient Air

    NASA Astrophysics Data System (ADS)

    Hassan, Ghassan; Yilbas, B. S.; Said, Syed A. M.; Al-Aqeeli, N.; Matin, Asif

    2016-07-01

    Mud formed from environmental dust particles in humid ambient air significantly influences the performance of solar harvesting devices. This study examines the characterization of environmental dust particles and the chemo-mechanics of dry mud formed from dust particles. Analytical tools, including scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, particle sizing, and X-ray diffraction, are used to characterize dry mud and dust particles. A micro/nano tribometer is used to measure the tangential force and friction coefficient while tensile tests are carried out to assess the binding forces of dry mud pellets. After dry mud is removed, mud residuals on the glass surface are examined and the optical transmittance of the glass is measured. Dust particles include alkaline compounds, which dissolve in water condensate and form a mud solution with high pH (pH = 7.5). The mud solution forms a thin liquid film at the interface of dust particles and surface. Crystals form as the mud solution dries, thus, increasing the adhesion work required to remove dry mud from the surface. Optical transmittance of the glass is reduced after dry mud is removed due to the dry mud residue on the surface.

  11. Chemo-Mechanical Characteristics of Mud Formed from Environmental Dust Particles in Humid Ambient Air

    PubMed Central

    Hassan, Ghassan; Yilbas, B. S.; Said, Syed A. M.; Al-Aqeeli, N.; Matin, Asif

    2016-01-01

    Mud formed from environmental dust particles in humid ambient air significantly influences the performance of solar harvesting devices. This study examines the characterization of environmental dust particles and the chemo-mechanics of dry mud formed from dust particles. Analytical tools, including scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, particle sizing, and X-ray diffraction, are used to characterize dry mud and dust particles. A micro/nano tribometer is used to measure the tangential force and friction coefficient while tensile tests are carried out to assess the binding forces of dry mud pellets. After dry mud is removed, mud residuals on the glass surface are examined and the optical transmittance of the glass is measured. Dust particles include alkaline compounds, which dissolve in water condensate and form a mud solution with high pH (pH = 7.5). The mud solution forms a thin liquid film at the interface of dust particles and surface. Crystals form as the mud solution dries, thus, increasing the adhesion work required to remove dry mud from the surface. Optical transmittance of the glass is reduced after dry mud is removed due to the dry mud residue on the surface. PMID:27445272

  12. Health behaviour change interventions for couples: A systematic review.

    PubMed

    Arden-Close, Emily; McGrath, Nuala

    2017-05-01

    Partners are a significant influence on individuals' health, and concordance in health behaviours increases over time in couples. Several theories suggest that couple-focused interventions for health behaviour change may therefore be more effective than individual interventions. A systematic review of health behaviour change interventions for couples was conducted. Systematic search methods identified randomized controlled trials (RCTs) and non-randomized interventions of health behaviour change for couples with at least one member at risk of a chronic physical illness, published from 1990-2014. We identified 14 studies, targeting the following health behaviours: cancer prevention (6), obesity (1), diet (2), smoking in pregnancy (2), physical activity (1) and multiple health behaviours (2). In four out of seven trials couple-focused interventions were more effective than usual care. Of four RCTs comparing a couple-focused intervention to an individual intervention, two found that the couple-focused intervention was more effective. The studies were heterogeneous, and included participants at risk of a variety of illnesses. In many cases the intervention was compared to usual care for an individual or an individual-focused intervention, which meant the impact of the couplebased content could not be isolated. Three arm studies could determine whether any added benefits of couple-focused interventions are due to adding the partner or specific content of couple-focused interventions. Statement of contribution What is already known on this subject? Health behaviours and health behaviour change are more often concordant across couples than between individuals in the general population. Couple-focused interventions for chronic conditions are more effective than individual interventions or usual care (Martire, Schulz, Helgeson, Small, & Saghafi, ). What does this study add? Identified studies targeted a variety of health behaviours, with few studies in any one area. Further

  13. Coupled influences of topography and wind on wildland fire behaviour

    Treesearch

    Rodman Linn; Judith Winterkamp; Carleton Edminster; Jonah J. Colman; William S. Smith

    2007-01-01

    Ten simulations were performed with the HIGRAD/FIRETEC wildfire behaviour model in order to explore its utility in studying wildfire behaviour in inhomogeneous topography. The goal of these simulations is to explore the potential extent of the coupling between the fire, atmosphere, and topography. The ten simulations described in this paper include five different...

  14. A constitutive multiphysics modeling for nearly incompressible dissipative materials: application to thermo-chemo-mechanical aging of rubbers

    NASA Astrophysics Data System (ADS)

    Lejeunes, S.; Eyheramendy, D.; Boukamel, A.; Delattre, A.; Méo, S.; Ahose, K. D.

    2017-07-01

    In this paper we investigate the modeling of chemo-physical evolution due to thermo-mechanical loadings at finite strain in soft materials. In particular we discuss the question of a proper and consistent thermodynamical formulation in the case of nearly incompressible materials. The objective of this phenomenological modeling is to represent the thermo-chemo-mechanical aging that occurs in filled rubbers during high-cycle fatigue for some specific loading conditions.

  15. Application of Silicon Selective Epitaxial Growth and Chemo-Mechanical Polishing to Bipolar and Soi Mosfet Devices.

    NASA Astrophysics Data System (ADS)

    Nguyen, Cuong Tan

    1994-01-01

    Polished Epitaxy, or the combination of silicon Selective Epitaxial Growth and Chemo-Mechanical Polishing, provides new flexibility in process and device design, including optimized isolation, planar active-area definition, low-capacitance contacts, and SOI thin films. In this work, Polished Epitaxy has been developed with particular effort on overcoming junction leakage problems widely reported in devices fabricated in similar processes. It was found that in addition to careful surface preparation and defect control in the selective epitaxy process, issues such as sidewall orientation, junction passivation, crystal annealing, and surface damage removal were equally important and needed to be addressed. Coupled with the proper processing steps, Polished Epitaxy was able to deliver material of comparable quality to bulk silicon, suitable for device applications. By growing epitaxy laterally over an oxide step followed by polishing, a pedestal structure was created in which a thin film of single-crystal silicon was formed over oxide. Serving as the extrinsic base contact to a T-Pedestal bipolar transistor device, this pedestal helped minimize the parasitic extrinsic-base-collector overlap capacitance. The cut-off frequency (f_ {T}) in a device with a 1.0-mu m wide emitter stripe was found to improve from 17GHz to 22GHz when the contact overlap was reduced from a more conventional, larger size of 1.0 mu m to 0.2 mum. It is expected that the high-frequency performance of this structure can still be improved further in an optimized process with reduced emitter and collector resistances. The same pedestal structure was applied to a Pedestal -SOI (Silicon-On-Insulator) MOSFET device concept. At one extreme, a conventional bulk MOSFET structure is obtained when the pedestal is not utilized; quasi-SOI occurs when the drain and part of the channel overlap with the pedestal over buried oxide; at the other extreme, complete-SOI behavior results when source, channel, and drain

  16. Efficacy of lasers as an adjunct to chemo-mechanical disinfection of infected root canals: a systematic review.

    PubMed

    Fransson, H; Larsson, K M; Wolf, E

    2013-04-01

    The aim was to evaluate the efficacy of various types of lasers used as an adjunct to chemo-mechanical disinfection of infected root canals with the outcome measures 'normal periapical condition' or 'reduction of microbial load'. PubMed, CENTRAL and ISI Web of Knowledge literature searches with specific indexing terms and a subsequent hand search were made with stated limits and criteria. Relevant publications were retrieved, followed by interpretation. The quality of each included publication was assessed as high, moderate or low. The initial search process yielded 234 publications. All abstracts of these publications were read, and the reference lists of relevant publications were hand-searched. Ten articles were read in full text and interpreted according to a data extraction form. Five were included in the systematic review and were assessed. A meta-analysis was impossible to perform because the included studies were heterogeneous with regard to study design, treatment and outcome measures. Positive effects were reported; however, no concluding evidence grade could be made because each included study was judged to have low quality, primarily due to lack of a power analysis, blinding and reproducibility. The evidence grade for whether lasers can be recommended as an adjunct to chemo-mechanical disinfection of infected root canals was insufficient. This does not necessarily imply that laser should not be used as an adjunct to root canal treatment but instead underscores the need for future high-quality studies.

  17. Chemo-mechanical caries removal with Papacarie™: case series with 84 reports and 12 months of follow-up.

    PubMed

    Bussadori, Sandra Kalil; Godoy, Camila Haddad Leal de; Alfaya, Thays Almeida; Fernandes, Kristianne Porta Santos; Mesquita-Ferrari, Raquel Agnelli; Motta, Lara Jansiski

    2014-03-01

    The aim of the present study was to determine the success rate after 12 months of follow-up in a series of cases in which chemo-mechanical caries removal (CMCR) was performed with Papacarie(TM), followed by restoration with glass ionomer cement. The development of conservative techniques for carious tissue removal and improvements in dental restoration materials have allowed better preservation of dental structures in the treatment of decayed teeth. Chemo-mechanical caries removal (CMCR) is a conservative atraumatic treatment option. Papacarie(TM) is a papain-based material developed to act only on the carious dentin, allowing its easy removal with a blunt curette. The study involved a total of 84 deciduous posterior teeth with occlusal dentinal caries. Only teeth without risk of pulp exposure were studied. After a period of 12 months, the restorations were evaluated based on criteria employed in previous studies. The radiographic evaluation revealed resorption and calcification of the affected teeth. The data were submitted to descriptive statistical analysis with the aid of the XLSTAT program. The success rate was 88.1% and 98.8% based on the clinical and radiographic evaluations, respectively. The difference between the success and failure rates was statistically significant (p < 0.0001). Papacarie(TM) is an effective product for CMCR on occlusal dentinal tissue in deciduous teeth, demonstrating a high clinical and radiographic success rate after 12 months of follow-up.

  18. Randomized controlled clinical trial of long-term chemo-mechanical caries removal using PapacarieTM gel

    PubMed Central

    MOTTA, Lara Jansiski; BUSSADORI, Sandra Kalil; CAMPANELLI, Ana Paula; da SILVA, André Luis; ALFAYA, Thays Almeida; de GODOY, Camila Haddad Leal; NAVARRO, Maria Fidela de Lima

    2014-01-01

    Objectives Compare the effectiveness of PapacarieTM gel for the chemo-mechanical removal of carious lesions on primary teeth to conventional caries removal with a low-speed bur with regard to execution time, clinical aspects and radiographic findings. Material and Methods A randomized controlled clinical trial with a split-mouth design was carried out. The sample was composed of 20 children aged four to seven years, in whom 40 deciduous teeth were randomly divided into two groups: chemo-mechanical caries removal with PapacarieTM and removal of carious dentin with a low-speed bur. Each child underwent both procedures and served as his/her own control. Restorations were performed with glass ionomer cement. The time required to perform the procedure was also analyzed. The patients underwent longitudinal clinical and radiographic follow-up of the restorations. Results No statistically significant difference between groups was found regarding the time required to perform the procedures and the radiographic follow up. Statistically significant differences between groups were found in the clinical evaluation at 6 and 18 months after treatment. Conclusion PapacarieTM is as effective as the traditional method for the removal of carious dentin on deciduous teeth, but offers the advantages of the preservation of sound dental tissue as well as the avoidance of sharp rotary instruments and local anesthesia. PMID:25141203

  19. Slime mould foraging behaviour as optically coupled logical operations

    NASA Astrophysics Data System (ADS)

    Mayne, R.; Adamatzky, A.

    2015-04-01

    Physarum polycephalum is a macroscopic plasmodial slime mould whose apparently 'intelligent' behaviour patterns may be interpreted as computation. We employ plasmodial phototactic responses to construct laboratory prototypes of NOT and NAND logical gates with electrical inputs/outputs and optical coupling in which the slime mould plays dual roles of computing device and electrical conductor. Slime mould logical gates are fault tolerant and resettable. The results presented here demonstrate the malleability and resilience of biological systems and highlight how the innate behaviour patterns of living substrates may be used to implement useful computation.

  20. Cytotoxicity and pro-inflammatory action of chemo-mechanical caries-removal agents against oral cells.

    PubMed

    Garcia-Contreras, Rene; Scougall-Vilchis, Rogelio J; Contreras-Bulnes, Rosalia; Kanda, Yumiko; Nakajima, Hiroshi; Sakagami, Hiroshi

    2014-01-01

    Chemo-mechanical caries removal eliminates the outermost portion of the infected layer, leaving behind healthy dentine surfaces, with scarce dental tissue damage; however, the safety of caries solvents has not been established. The aim of the present study was to investigate the possible cytotoxicity of two popular chemo-mechanical caries removal agents. The cytotoxicity of Carisolv, Papacarie Duo and control vehicle solution (0.155-20% v/v) against human oral squamous cell carcinoma cells (HCS-2, HSC-3, HSC-4, Ca9-22) human gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 (PGE2) was quantified by enzyme-linked immunosorbent assay. Changes in fine cell structure were assessed by transmission electron microscopy. Carisolv exhibited neither cytotoxicity nor hormetic growth stimulation. Papacarie Duo significantly reduced the viable cell number within 30 min. HSC-4 exhibited the highest sensitivity, followed by HSC-2>HSC-3>HPLF>Ca9-22>HPC>HGF cells. Interleukin-1β (3 ng/ml) stimulated HGF, but not HPC cells to produce PGE2 in the culture medium. Papacarie Duo stimulated HGF cells to produce PGE2 in synergistic fashion with interleukin-1β. Carisolv had acceptable biocompatibility with both normal and cancerous oral cells. On the other hand, Papacarie Duo had a rapid but slight cytotoxicity and pro-inflammatory action against oral cells, suggesting the importance of careful application of this agent. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  1. Partially synchronized states in an ensemble of chemo-mechanical oscillators

    NASA Astrophysics Data System (ADS)

    Kumar, Pawan; Verma, Dinesh Kumar; Parmananda, P.

    2017-08-01

    Partially synchronized (clustered) states are defined as coexisting coherent (synchronized) and incoherent (unsynchronized) domains in an ensemble of interacting oscillators. We report these clustered states in experiments involving an ensemble of sixteen mercury beating heart (MBH) oscillators. These oscillators interact via resistors and are subjected to two different network schemes: 1) All to all and 2) Nonlocal. For the all to all network, the coupling strengths were inhomogeneously distributed, whereas for the nonlocal network scenario, each oscillator was coupled, with an identical coupling strength, with four of its nearest neighbors in either direction. For both of these network schemes, partially synchronized states results into grouping of these oscillators, wherein some oscillators are synchronized and rest are unsynchronized. For all to all network, the partially synchronized states are observed, for the intermediate inhomogeneities, when subjected to the power law and the 'U' shape profiles of coupling strengths. Irrespective of the coupling profile chosen, low inhomogeneities in the coupling strengths leaves all the oscillators in a single coherent state whereas for the high inhomogeneities scenarios oscillators are located in the incoherent domain. In comparison, for the nonlocal network partially synchronized states emerge when the coupling constant is appropriately chosen. The experimental results for both these network scenarios have been analyzed using the redox time series (chemical activity) and the time evolution of the normalized areas for the mercury drop (mechanical activity). The existence of partially synchronized states in the experiments was verified using different diagnostic tools such as time series plot, space-time plot and average frequency.

  2. A comparative microbiological study to assess caries excavation by conventional rotary method and a chemo-mechanical method

    PubMed Central

    Anegundi, Rajesh T.; Patil, Shruthi B.; Tegginmani, Viresh; Shetty, Sheetal D.

    2012-01-01

    Aims: This study was aimed to determine the effectiveness of Papacárie® for caries removal as compared to the conventional method with respect to microbial flora, time, the amount of tissue removal, child's behavior, pain perception, and preference of treatment. Materials and Methods: Sixty primary molars of 30 children of age 4-9 years were selected randomly and divided into two groups of 30 teeth each: Group A treated by conventional method and group B with Papacárie® method. Results: Comparatively, no statistical difference was seen in microbial growth, total bacterial count, and lactobacilli count in both the groups (P = 0.36). The mean cavity entrance size with group A was 0.98133 mm and group B was 0.26083 mm (P < 0.001). The mean preparation time for group A was 4.7 Mins (minutes) and group B was 17.96 min s (P < 0.001). Majority of kids of both group A and B scored 3 (Frankl Behavior Rating Scale) before and after the treatment showing no statistical difference in their behavioral score (P = 1). In group A 50% of children experienced no pain as compared to 86.7% in group B (P = 0.01). There was no statistical difference in the preference of treatment (P = 0.12). Conclusion: Thus, the Chemo mechanical caries removal method can be considered as an effective method to control pain and preserve sound tooth structure during caries excavation. PMID:23633794

  3. A comparative microbiological study to assess caries excavation by conventional rotary method and a chemo-mechanical method.

    PubMed

    Anegundi, Rajesh T; Patil, Shruthi B; Tegginmani, Viresh; Shetty, Sheetal D

    2012-10-01

    This study was aimed to determine the effectiveness of Papacárie(®) for caries removal as compared to the conventional method with respect to microbial flora, time, the amount of tissue removal, child's behavior, pain perception, and preference of treatment. Sixty primary molars of 30 children of age 4-9 years were selected randomly and divided into two groups of 30 teeth each: Group A treated by conventional method and group B with Papacárie(®) method. Comparatively, no statistical difference was seen in microbial growth, total bacterial count, and lactobacilli count in both the groups (P = 0.36). The mean cavity entrance size with group A was 0.98133 mm and group B was 0.26083 mm (P < 0.001). The mean preparation time for group A was 4.7 Mins (minutes) and group B was 17.96 min s (P < 0.001). Majority of kids of both group A and B scored 3 (Frankl Behavior Rating Scale) before and after the treatment showing no statistical difference in their behavioral score (P = 1). In group A 50% of children experienced no pain as compared to 86.7% in group B (P = 0.01). There was no statistical difference in the preference of treatment (P = 0.12). Thus, the Chemo mechanical caries removal method can be considered as an effective method to control pain and preserve sound tooth structure during caries excavation.

  4. Microleakage Evaluation of Composite Restorations Following Papain-Based Chemo-Mechanical Caries Removal in Primary Teeth.

    PubMed

    Hafez, Marwa Abdel; Elkateb, Mona; El Shabrawy, Sonia; Mahmoud, Amel; El Meligy, Omar

    To evaluate the microleakage of composite restorations following Papain-based chemo-mechanical caries removal compared to the conventional drilling method. The characteristic of the hybrid layer was also studied using scanning electron microscopy. The sample included thirty freshly extracted and exfoliated primary molars with open proximal carious dentin lesions. Teeth were divided into two equal groups, according to method of caries removal. Following caries removal, cavity preparations were restored with composite resin. After thermocycling, teeth were sealed apically and coated with nail polish except the surface of restorations and the surrounding 1mm. Teeth were immersed in basic fuschin dye solution, then they were sectioned mesiodistally. The extent of dye penetration was detected using a light stereomicroscope. After microleakage test, the resin/dentin interface was examined using scanning electron microscopy. There was no significant difference in the degree of leakage between both groups. In the Papacarie group, longer and numerous resin tags were observed with statistically significant thicker hybrid layer than those following the drilling method. However, there was no significant difference between the diameters of resin tags of both groups. Papacarie does not adversely affect the microleakage of composite restorations and provides a suitable surface for bonding.

  5. Microwave, ultrasonic and chemo-mechanical pretreatments for enhancing methane potential of pulp mill wastewater treatment sludge.

    PubMed

    Saha, Mithun; Eskicioglu, Cigdem; Marin, Juan

    2011-09-01

    Microwave (2450 MHz, 1250 W), ultrasonic (20 kHz, 400 W) and chemo-mechanical (MicroSludge® with 900 mg/L NaOH followed by 83,000 kPa) pretreatments were applied to pulp mill waste sludge to enhance methane production and reduce digester sludge retention time. The effects of four variables (microwave temperature in a range of 50-175°C) and sonication time (15-90 min), sludge type (primary or secondary) and digester temperature (mesophilic and thermophilic) were investigated. Microwave pretreatment proved to be the most effective, increasing specific methane yields of WAS samples by 90% compared to controls after 21 days of mesophilic digestion. Sonication solubilized the sludge samples better, but resulted in soluble non-biodegradable compounds. Based on the laboratory scale data, MicroSludge® was found the least energy intensive pretreatment followed by sonication for 15 min alternative with net energy profits of 1366 and 386 kWh/tonne of total solids (TS), respectively. Pretreatment benefits were smaller for thermophilic digesters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. The atomic-scale removal mechanism during chemo-mechanical polishing of Si(100) and Si(111)

    NASA Astrophysics Data System (ADS)

    Pietsch, G. J.; Chabal, Y. J.; Higashi, G. S.

    1995-07-01

    Chemo-mechanical polishing (CMP) of silicon with a colloidal suspension of silica ("Siton") is the standard technology for the preparation of smooth, defect-free silicon starting surfaces for microelectronic device patterning. Despite its importance in device manufacturing, little is known about the microscopic removal mechanism during CMP that controls the resulting surface properties. With infrared spectroscopy we find that, after CMP, a surface termination by hydrogen predominates on Si(111) and Si(100). This H-termination is responsible for the observed strong hydrophobicity of the surface and its chemical stability (passivation) in air. Hydrophobicity (contact angle) and polishing removal rate strongly depend on the slurry pH and peak at pH ≈ 11. At this optimum pH a nearly "ideal" termination by monohydride is found on Si(111) which points to perfect atomic-scale surface planarity and chemical homogeneity. Si(100), after CMP, exhibits a more complex H-termination by mono-, di-, and trihydrides. At higher or lower pH, OH groups replace some of the hydride species both on CMP-Si(111) and CMP-Si(100). We present a microscopic removal mechanism which — on an atomic scale — is determined by an interplay of local oxidation by OH - and passivation by hydrogen.

  7. Allosteric ring assembly and chemo-mechanical melting by the interaction between 5′-phosphate and λ exonuclease

    PubMed Central

    Yoo, Jungmin; Lee, Gwangrog

    2015-01-01

    Phosphates along the DNA function as chemical energy frequently used by nucleases to drive their enzymatic reactions. Exonuclease functions as a machine that converts chemical energy of the phosphodiester-chain into mechanical work. However, the roles of phosphates during exonuclease activities are unknown. We employed λ exonuclease as a model system and investigated the roles of phosphates during degradation via single-molecule fluorescence resonance energy transfer (FRET). We found that 5′ phosphates, generated at each cleavage step of the reaction, chemo-mechanically facilitate the subsequent post-cleavage melting of the terminal base pairs. Degradation of DNA with a nick requires backtracking and thermal fraying at the cleavage site for re-initiation via the formation of a catalytically active complex. Unexpectedly, we discovered that a phosphate of a 5′ recessed DNA acts as a hotspot for an allosteric trimeric-ring assembly without passing through the central channel. Our study provides new insight into the versatile roles of phosphates during the processive enzymatic reaction. PMID:26527731

  8. A chemo-mechanical model for the acoustic nonlinearity change in concrete with alkali-silica reactions

    NASA Astrophysics Data System (ADS)

    Liu, M.; Jacobs, L. J.; Qu, J.

    2013-01-01

    Experimental data have demonstrated that damage induced by alkali-silica reaction (ASR) in concrete, even in its very early stage, can cause changes in the acoustic nonlinearity parameter β. This provides a means to characterize ASR damage in concrete nondestructively. However, there is currently no model that explains the relationship between the acoustic nonlinearity parameter and ASR damage. In this work, we present a micromechanics-based chemo-mechanical model that relates the acoustic nonlinearity parameter to ASR damage. The mechanical part of the model is developed based on a modified version of the generalized self-consistent theory. The chemical part of the model accounts for two opposing diffusion processes. One is the diffusion of alkali ions in the pore solution into aggregates, and the other is the permeation of ASR gel from the aggregate surface into the surrounding porous cement matrix. Furthermore, a fracture model is used to simulate crack initiation and growth, so that the crack density and total expansion can be obtained. Finally, the acoustic nonlinearity parameter is determined as a function of exposure time by accounting for the gel pressure and the crack density. This model provides a way to quantitatively predict the changes in the acoustic nonlinearity parameter due to ASR damage, which can be used to guide experimental measurements for nondestructive evaluation of ASR damage.

  9. Molecular control of myocardial mechanics and energetics: the chemo-mechanical conversion.

    PubMed

    Landesberg, A

    1997-01-01

    Energy consumption in the cardiac muscle is characterized by two basic phenomena: 1) The well known linear relationship between energy consumption by the sarcomere and the mechanical energy it generates, and 2) the ability to modulate the generated mechanical energy and energy consumption to the various loading conditions, as is manifested by the Frank-Starling Law and the Fenn effect. These basic phenomena are analyzed here based on coupling calcium kinetics with crossbridge (Xb) cycling. Our previous studies established the existence of two feedback mechanism: 1) a positive feedback mechanism, the cooperativity, whereby the affinity of the troponin for calcium, and hence Xb and actomyosin-ATPase recruitment, depends on the number of force generating Xbs, and 2) a mechanical feedback, whereby the filaments shortening velocity, or the Xb strain rate, determines the rate of Xb turnover from the strong to the weak conformation. The cooperativity mechanism determines the force-length relationship (FLR) and the related Frank-Starling Law. It also provides the basis for the regulation of energy consumption and the ability of the muscle to adapt its energy consumption to the loading conditions. The mechanical feedback regulates the shortening velocity and provides the analytical solution for the experimentally derived Hill's equation for the force-velocity relationship (FVR). The mechanical feedback regulates the generated power and provides the linear relationship between energy consumption and the generated mechanical energy, i.e., the external work done and the liberated heat. Thus, the two feedback mechanisms that regulate sarcomere dynamics, and determine the FLR and FVR, also regulate the energy consumption and the mechanical energy generated by the muscle.

  10. Quantification of cultivable bacteria and endotoxin in post-treatment apical periodontitis before and after chemo-mechanical preparation.

    PubMed

    Endo, M S; Martinho, F C; Zaia, A A; Ferraz, C C R; Almeida, J F A; Gomes, B P F A

    2012-10-01

    This clinical study was conducted to quantify cultivable bacteria and endotoxin in root canals with post-treatment apical periodontitis by correlating their levels with clinical features and to evaluate the effect of chemo-mechanical preparation (CMP) with 2 % chlorhexidine gel + 17 % EDTA on bacterial and endotoxin removal/elimination. Moreover, target strict Gram-negative anaerobic bacteria were investigated by polymerase chain reaction (PCR). Fifteen teeth with post-treatment apical periodontitis were sampled before (s1) and after (s2) CMP. Culture techniques determined the number of colony-forming units (CFU). PCR (16S rDNA) and limulus amebocyte lysate (LAL) assay were used for bacterial and endotoxin detection, respectively. Prevotella nigrescens (4/15), Prevotella intermedia (2/15), and Tannerella forsythia (2/15) were the most frequently detected species. Endotoxin was recovered in 100 % of the samples. At s1, bacteria and endotoxin were detected at a median value of 5.14 × 10(3) CFU/mL and 3.96 EU/mL, respectively. Higher levels of endotoxin were related to a larger size of radiolucent area (>5 mm) (p < 0.05). CMP was more effective in reducing bacteria (99.61 %) than endotoxin (60.6 %) (both p < 0.05). Our findings indicated that the levels of endotoxin found in infected root canals were related to a larger size of radiolucent area in the periapical region. Moreover, CMP was effective in reducing both bacterial and endotoxin contents in post-treatment apical periodontitis.

  11. Caries-removal effectiveness of a papain-based chemo-mechanical agent: A quantitative micro-CT study.

    PubMed

    Neves, Aline A; Lourenço, Roseane A; Alves, Haimon D; Lopes, Ricardo T; Primo, Laura G

    2015-01-01

    The aim of this study was to access the effectiveness and specificity of a papain-based chemo-mechanical caries-removal agent in providing minimum residual caries after cavity preparation. In order to do it, extracted carious molars were selected and scanned in a micro-CT before and after caries-removal procedures with the papain-based gel. Similar parameters for acquisition and reconstruction of the image stacks were used between the scans. After classification of the dentin substrate based on mineral density intervals and establishment of a carious tissue threshold, volumetric parameters related to effectiveness (mineral density of removed dentin volume and residual dentin tissue) and specificity (relation between carious dentin in removed volume and initial caries) of this caries-removal agent were obtained. In general, removed dentin volume was similar or higher than the initial carious volume, indicating that the method was able to effectively remove dentin tissue. Samples with an almost perfect accuracy in carious dentin removal also showed an increased removal of caries-affected tissue. On the contrary, less or no affected dentin was removed in samples where some carious tissue was left in residual dentin. Mineral density values in residual dentin were always higher or similar to the threshold for mineral density values in carious dentin. In conclusion, the papain-based gel was effective in removing carious dentin up to a conservative in vitro threshold. Lesion characteristics, such as activity and morphology of enamel lesion, may also influence caries-removal properties of the method. © Wiley Periodicals, Inc.

  12. Couple interdependence impacts HIV-related health behaviours among pregnant couples in southwestern Kenya: a qualitative analysis.

    PubMed

    Rogers, Anna Joy; Achiro, Lillian; Bukusi, Elizabeth A; Hatcher, Abigail M; Kwena, Zachary; Musoke, Pamela L; Turan, Janet M; Weke, Elly; Darbes, Lynae A

    2016-01-01

    HIV infection is frequently transmitted within stable couple partnerships. In order to prevent HIV acquisition in HIV-negative couples, as well as improve coping in couples with an HIV-positive diagnosis, it has been suggested that interventions be aimed at strengthening couple relationships, in addition to addressing individual behaviours. However, little is known about factors that influence relationships to impact joint decision-making related to HIV. We conducted qualitative in-depth interviews with 40 pregnant women and 40 male partners in southwestern Kenya, an area of high HIV prevalence. Drawing from the interdependence model of communal coping and health behaviour change, we employed thematic analysis methods to analyze interview transcripts in Dedoose software with the aim of identifying key relationship factors that could contribute to the development of a couples-based intervention to improve health outcomes for pregnant women and their male partners. In accordance with the interdependence model, we found that couples with greater relationship-centred motivations described jointly engaging in more health-enhancing behaviours, such as couples HIV testing, disclosure of HIV status, and cooperation to improve medication and clinic appointment adherence. These couples often had predisposing factors such as stronger communication skills and shared children, and were less likely to face potential challenges such as polygamous marriages, wife inheritance, living separately, or financial difficulties. For HIV-negative couples, joint decision-making helped them face the health threat of acquiring HIV together. For couples with an HIV-positive diagnosis, communal coping helped reduce risk of interspousal transmission and improve long-term health prospects. Conversely, participants felt that self-centred motivations led to more concurrent sexual partnerships, reduced relationship satisfaction, and mistrust. Couples who lacked interdependence were more likely to

  13. Couple interdependence impacts HIV-related health behaviours among pregnant couples in southwestern Kenya: a qualitative analysis

    PubMed Central

    Rogers, Anna Joy; Achiro, Lillian; Bukusi, Elizabeth A; Hatcher, Abigail M; Kwena, Zachary; Musoke, Pamela L; Turan, Janet M; Weke, Elly; Darbes, Lynae A

    2016-01-01

    Introduction HIV infection is frequently transmitted within stable couple partnerships. In order to prevent HIV acquisition in HIV-negative couples, as well as improve coping in couples with an HIV-positive diagnosis, it has been suggested that interventions be aimed at strengthening couple relationships, in addition to addressing individual behaviours. However, little is known about factors that influence relationships to impact joint decision-making related to HIV. Methods We conducted qualitative in-depth interviews with 40 pregnant women and 40 male partners in southwestern Kenya, an area of high HIV prevalence. Drawing from the interdependence model of communal coping and health behaviour change, we employed thematic analysis methods to analyze interview transcripts in Dedoose software with the aim of identifying key relationship factors that could contribute to the development of a couples-based intervention to improve health outcomes for pregnant women and their male partners. Results In accordance with the interdependence model, we found that couples with greater relationship-centred motivations described jointly engaging in more health-enhancing behaviours, such as couples HIV testing, disclosure of HIV status, and cooperation to improve medication and clinic appointment adherence. These couples often had predisposing factors such as stronger communication skills and shared children, and were less likely to face potential challenges such as polygamous marriages, wife inheritance, living separately, or financial difficulties. For HIV-negative couples, joint decision-making helped them face the health threat of acquiring HIV together. For couples with an HIV-positive diagnosis, communal coping helped reduce risk of interspousal transmission and improve long-term health prospects. Conversely, participants felt that self-centred motivations led to more concurrent sexual partnerships, reduced relationship satisfaction, and mistrust. Couples who lacked

  14. True-slime-mould-inspired hydrostatically coupled oscillator system exhibiting versatile behaviours.

    PubMed

    Umedachi, Takuya; Idei, Ryo; Ito, Kentaro; Ishiguro, Akio

    2013-09-01

    Behavioural diversity is an indispensable attribute of living systems, which makes them intrinsically adaptive and responsive to the demands of a dynamically changing environment. In contrast, conventional engineering approaches struggle to suppress behavioural diversity in artificial systems to reach optimal performance in given environments for desired tasks. The goals of this research include understanding the essential mechanism that endows living systems with behavioural diversity and implementing the mechanism in robots to exhibit adaptive behaviours. For this purpose, we have focused on an amoeba-like unicellular organism: the plasmodium of true slime mould. Despite the absence of a central nervous system, the plasmodium exhibits versatile spatiotemporal oscillatory patterns and switches spontaneously among these patterns. By exploiting this behavioural diversity, it is able to exhibit adaptive behaviour according to the situation encountered. Inspired by this organism, we built a real physical robot using hydrostatically coupled oscillators that produce versatile oscillatory patterns and spontaneous transitions among the patterns. The experimental results show that exploiting physical hydrostatic interplay—the physical dynamics of the robot—allows simple phase oscillators to promote versatile behaviours. The results can contribute to an understanding of how a living system generates versatile and adaptive behaviours with physical interplays among body parts.

  15. Marginal Micro-leakage of Self-etch and All-in One Adhesives to Primary Teeth, with Mechanical or Chemo-Mechanical Caries Removal.

    PubMed

    A, Nouzari; A, Zohrei; M, Ferooz; N, Mohammadi

    2016-06-01

    Chemo-mechanical caries removal is an effective alternative to the traditional rotary drilling method. One of the factors that can influence micro-leakage is the method of caries removal. To compare the micro-leakage of resin composite in primary dentition using self-etch and all-in one adhesives following conventional and chemo-mechanical caries removal. Sixty extracted human primary anterior teeth with class III carious lesions were collected. The selected teeth were divided randomly into two groups each consisting of 30 teeth. In group1 carious lesions were removed using Carisolv multi mix gel. In group 2, caries was removed using round steel burs in a slow-speed hand piece. Then, the specimens in each group were randomly divided into two subgroups (A and B) of 15 and treated by either Clearfil SE Bond (CSEB) or Scotch bond. All prepared cavities were filled with a resin composite (Estellite). All the specimens were stored in distilled water at 37ºC for 24 hours and then thermocycled in 5ºC and 55ºC water with a dwell time of 20 seconds for 1500 cycles. The specimens were immersed in 1% methylene blue solution for 24 hours, removed, washed and sectioned mesiodistally. The sectioned splits were examined under a stereomicroscope to determine the micro-leakage scores. The data were analyzed using Kruskal-Wallis Test in SPSS version 21. There were no significant differences between micro-leakage scores among the four groups (p = 0.127). Score 0 of micro-leakage was detected for 60% of the specimens in group 1-A (Carisolv + CSEB), 73% of the group 2-A (hand piece + CSEB), 80% of the group 1-B (Carisolv + Scotch bond), and 93% of the group 2-B in which caries was removed using hand piece and bonded with Scotch bond . Although caries removal using hand piece bur along with using Scotch bond adhesive performed less micro-leakage, it would seems that the use of Carisolv doesn't adversely affect the micro-leakage of composite restorations while using self-etch or all

  16. Marginal Micro-leakage of Self-etch and All-in One Adhesives to Primary Teeth, with Mechanical or Chemo-Mechanical Caries Removal

    PubMed Central

    A, Nouzari; A, Zohrei; M, Ferooz; N, Mohammadi

    2016-01-01

    Statement of Problem: Chemo-mechanical caries removal is an effective alternative to the traditional rotary drilling method. One of the factors that can influence micro-leakage is the method of caries removal. Objectives: To compare the micro-leakage of resin composite in primary dentition using self-etch and all-in one adhesives following conventional and chemo-mechanical caries removal. Materials and Methods: Sixty extracted human primary anterior teeth with class III carious lesions were collected. The selected teeth were divided randomly into two groups each consisting of 30 teeth. In group1 carious lesions were removed using Carisolv multi mix gel. In group 2, caries was removed using round steel burs in a slow-speed hand piece. Then, the specimens in each group were randomly divided into two subgroups (A and B) of 15 and treated by either Clearfil SE Bond (CSEB) or Scotch bond. All prepared cavities were filled with a resin composite (Estellite). All the specimens were stored in distilled water at 37ºC for 24 hours and then thermocycled in 5ºC and 55ºC water with a dwell time of 20 seconds for 1500 cycles. The specimens were immersed in 1% methylene blue solution for 24 hours, removed, washed and sectioned mesiodistally. The sectioned splits were examined under a stereomicroscope to determine the micro-leakage scores. The data were analyzed using Kruskal-Wallis Test in SPSS version 21. Results: There were no significant differences between micro-leakage scores among the four groups (p = 0.127). Score 0 of micro-leakage was detected for 60% of the specimens in group 1-A (Carisolv + CSEB), 73% of the group 2-A (hand piece + CSEB), 80% of the group 1-B (Carisolv + Scotch bond), and 93% of the group 2-B in which caries was removed using hand piece and bonded with Scotch bond . Conclusions: Although caries removal using hand piece bur along with using Scotch bond adhesive performed less micro-leakage, it would seems that the use of Carisolv doesn’t adversely

  17. Sensitivity Comparison of Vapor Trace Detection of Explosives Based on Chemo-Mechanical Sensing with Optical Detection and Capacitive Sensing with Electronic Detection

    PubMed Central

    Strle, Drago; Štefane, Bogdan; Zupanič, Erik; Trifkovič, Mario; Maček, Marijan; Jakša, Gregor; Kvasič, Ivan; Muševič, Igor

    2014-01-01

    The article offers a comparison of the sensitivities for vapour trace detection of Trinitrotoluene (TNT) explosives of two different sensor systems: a chemo-mechanical sensor based on chemically modified Atomic Force Microscope (AFM) cantilevers based on Micro Electro Mechanical System (MEMS) technology with optical detection (CMO), and a miniature system based on capacitive detection of chemically functionalized planar capacitors with interdigitated electrodes with a comb-like structure with electronic detection (CE). In both cases (either CMO or CE), the sensor surfaces are chemically functionalized with a layer of APhS (trimethoxyphenylsilane) molecules, which give the strongest sensor response for TNT. The construction and calibration of a vapour generator is also presented. The measurements of the sensor response to TNT are performed under equal conditions for both systems, and the results show that CE system with ultrasensitive electronics is far superior to optical detection using MEMS. Using CMO system, we can detect 300 molecules of TNT in 10+12 molecules of N2 carrier gas, whereas the CE system can detect three molecules of TNT in 10+12 molecules of carrier N2. PMID:24977388

  18. Micro-structural analysis of local damage introduced in subsurface regions of 4H-SiC wafers during chemo-mechanical polishing

    NASA Astrophysics Data System (ADS)

    Sako, Hideki; Matsuhata, Hirofumi; Sasaki, Masayuki; Nagaya, Masatake; Kido, Takanori; Kawata, Kenji; Kato, Tomohisa; Senzaki, Junji; Kitabatake, Makoto; Okumura, Hajime

    2016-04-01

    The surface morphology and lattice defect structures in the subsurface regions of 4H-SiC wafers introduced during chemo-mechanical polishing (CMP) were studied by scanning electron microscopy and transmission electron microscopy. It is known that local damage consisting of high-density lattice defects is introduced in the wafers during the current CMP, however, optical microscopy showed that the surface was very flat and clean without any presence of surface defects. Specifically, this study focused on the detailed analysis of such lattice defect structures. The high-density lattice defects locally introduced in the subsurface regions consisted of nano-scale surface scratches, high-density basal-plane dislocation loops, Shockley-type stacking faults, and Y-shaped defects. Two types of dislocation loops were introduced near the scratches that were selected for further study: nearly perfect basal-plane dislocations, which were accompanied by narrow stacking faults, and apparent partial basal-plane dislocations, which were accompanied by wide stacking faults. A Y-shaped defect was observed in the local damage along the [ 11 2 ¯ 0 ] direction, but not in the local damage along the [ 1 ¯100 ] direction. It was also found that the directions of the Burgers vectors for the basal-plane dislocations clearly depended on the directions of the introduced scratch-like defects.

  19. Sensitivity comparison of vapor trace detection of explosives based on chemo-mechanical sensing with optical detection and capacitive sensing with electronic detection.

    PubMed

    Strle, Drago; Štefane, Bogdan; Zupanič, Erik; Trifkovič, Mario; Maček, Marijan; Jakša, Gregor; Kvasič, Ivan; Muševič, Igor

    2014-06-27

    The article offers a comparison of the sensitivities for vapour trace detection of Trinitrotoluene (TNT) explosives of two different sensor systems: a chemo-mechanical sensor based on chemically modified Atomic Force Microscope (AFM) cantilevers based on Micro Electro Mechanical System (MEMS) technology with optical detection (CMO), and a miniature system based on capacitive detection of chemically functionalized planar capacitors with interdigitated electrodes with a comb-like structure with electronic detection (CE). In both cases (either CMO or CE), the sensor surfaces are chemically functionalized with a layer of APhS (trimethoxyphenylsilane) molecules, which give the strongest sensor response for TNT. The construction and calibration of a vapour generator is also presented. The measurements of the sensor response to TNT are performed under equal conditions for both systems, and the results show that CE system with ultrasensitive electronics is far superior to optical detection using MEMS. Using CMO system, we can detect 300 molecules of TNT in 10(+12) molecules of N2 carrier gas, whereas the CE system can detect three molecules of TNT in 10(+12) molecules of carrier N2.

  20. Quality of Life and Marital Adjustment after Cognitive Behavioural Therapy and Behavioural Marital Therapy in Couples with Anxiety Disorders

    PubMed Central

    Kavitha, Chirumamilla; Rangan, Uma

    2014-01-01

    Background: Anxiety disorders may affect nearly one in four persons and may cause significant impairment of interpersonal relationships including marital relationships. The effect of the disorder on the spouse and the impact of including the spouse in therapy are not well studied. Aim: To determine if Cognitive Behavioural Therapy (CBT) improves the quality of life of participants with anxiety disorders and if marital adjustment of couples with anxiety disorders can be improved with Behavioural Marital Therapy (BMT), relative to standard care of pharmacotherapy and psychoeducation. Methods: An open label randomised controlled trial. Participants were randomly assigned to CBT+BMT or standard of care. Final assessments were carried out at 3.5 months after baseline. Quality of life was assessed using the WHOQOL-Bref instrument and Marital adjustment was measured using a marital quality scale. Chi-square test, student’s t-test and Analysis of Variance (ANOVA) and Effect sizes with Cohen’s d were used to compare differences between groups. Results: Clinically meaningful effect sizes for the CBT+ BMT intervention were evident for the marital adjustment scores among participants (d=0.63) and their spouses (d=1.29), and for the psychological (d=0.84), social (d=0.72) and environmental (d=0.52) domains of the WHOQOL of participants and psychological (d=0.86), social (d=0.32) and environmental domains (d=1.01) of the WHOQOL of spouses of participants. Conclusion: CBT for the partner with anxiety disorder and BMT for couples with anxiety disorders and marital discord and involvement of the spouse in the therapy will be a useful addition to the management of a couple where one partner has an anxiety disorder. PMID:25302250

  1. A cell-based computational model of early embryogenesis coupling mechanical behaviour and gene regulation

    NASA Astrophysics Data System (ADS)

    Delile, Julien; Herrmann, Matthieu; Peyriéras, Nadine; Doursat, René

    2017-01-01

    The study of multicellular development is grounded in two complementary domains: cell biomechanics, which examines how physical forces shape the embryo, and genetic regulation and molecular signalling, which concern how cells determine their states and behaviours. Integrating both sides into a unified framework is crucial to fully understand the self-organized dynamics of morphogenesis. Here we introduce MecaGen, an integrative modelling platform enabling the hypothesis-driven simulation of these dual processes via the coupling between mechanical and chemical variables. Our approach relies upon a minimal `cell behaviour ontology' comprising mesenchymal and epithelial cells and their associated behaviours. MecaGen enables the specification and control of complex collective movements in 3D space through a biologically relevant gene regulatory network and parameter space exploration. Three case studies investigating pattern formation, epithelial differentiation and tissue tectonics in zebrafish early embryogenesis, the latter with quantitative comparison to live imaging data, demonstrate the validity and usefulness of our framework.

  2. A cell-based computational model of early embryogenesis coupling mechanical behaviour and gene regulation.

    PubMed

    Delile, Julien; Herrmann, Matthieu; Peyriéras, Nadine; Doursat, René

    2017-01-23

    The study of multicellular development is grounded in two complementary domains: cell biomechanics, which examines how physical forces shape the embryo, and genetic regulation and molecular signalling, which concern how cells determine their states and behaviours. Integrating both sides into a unified framework is crucial to fully understand the self-organized dynamics of morphogenesis. Here we introduce MecaGen, an integrative modelling platform enabling the hypothesis-driven simulation of these dual processes via the coupling between mechanical and chemical variables. Our approach relies upon a minimal 'cell behaviour ontology' comprising mesenchymal and epithelial cells and their associated behaviours. MecaGen enables the specification and control of complex collective movements in 3D space through a biologically relevant gene regulatory network and parameter space exploration. Three case studies investigating pattern formation, epithelial differentiation and tissue tectonics in zebrafish early embryogenesis, the latter with quantitative comparison to live imaging data, demonstrate the validity and usefulness of our framework.

  3. Coupling tendencies during exploratory behaviours of competing players in rugby union dyads.

    PubMed

    Correia, Vanda; Passos, Pedro; Araújo, Duarte; Davids, Keith; Diniz, Ana; Kelso, J A Scott

    2016-01-01

    This study investigated interpersonal coordination tendencies in 1vs.1 dyads in rugby union, here expressed by participants' movement velocity towards or away from the sideline as they competed to score or prevent a try. We examined whether coupling tendencies of members of each dyad shaped key performance outcomes (try or successful tackle). Data on movement displacement trajectories of eight male rugby union players (aged 11-12 years) were analysed during performance in 47 trials. To assess coordination tendencies during exploratory behaviours in the dyads, analyses of performance time series data were undertaken using variable time graphs, running correlations and cross-correlations. Results revealed distinct coupling patterns characterised by shifts between synchronous coordination and asynchronous coordination tendencies and uncoordinated actions. Observed behaviours were interpreted as attempts of competing participants to create and perceive possibilities for action while seeking to achieve specific performance goals. Findings also revealed that a variety of patterned relations between participants resulted in different performance outcomes.

  4. Emergence of global scaling behaviour in the coupled Earth-atmosphere interaction

    PubMed Central

    Fallah, Bijan; Saberi, Abbas Ali; Sodoudi, Sahar

    2016-01-01

    Scale invariance property in the global geometry of Earth may lead to a coupled interactive behaviour between various components of the climate system. One of the most interesting correlations exists between spatial statistics of the global topography and the temperature on Earth. Here we show that the power-law behaviour observed in the Earth topography via different approaches, resembles a scaling law in the global spatial distribution of independent atmospheric parameters. We report on observation of scaling behaviour of such variables characterized by distinct universal exponents. More specifically, we find that the spatial power-law behaviour in the fluctuations of the near surface temperature over the lands on Earth, shares the same universal exponent as of the global Earth topography, indicative of the global persistent role of the static geometry of Earth to control the steady state of a dynamical atmospheric field. Such a universal feature can pave the way to the theoretical understanding of the chaotic nature of the atmosphere coupled to the Earth’s global topography. PMID:27666675

  5. Emergence of global scaling behaviour in the coupled Earth-atmosphere interaction

    NASA Astrophysics Data System (ADS)

    Fallah, Bijan; Saberi, Abbas Ali; Sodoudi, Sahar

    2016-09-01

    Scale invariance property in the global geometry of Earth may lead to a coupled interactive behaviour between various components of the climate system. One of the most interesting correlations exists between spatial statistics of the global topography and the temperature on Earth. Here we show that the power-law behaviour observed in the Earth topography via different approaches, resembles a scaling law in the global spatial distribution of independent atmospheric parameters. We report on observation of scaling behaviour of such variables characterized by distinct universal exponents. More specifically, we find that the spatial power-law behaviour in the fluctuations of the near surface temperature over the lands on Earth, shares the same universal exponent as of the global Earth topography, indicative of the global persistent role of the static geometry of Earth to control the steady state of a dynamical atmospheric field. Such a universal feature can pave the way to the theoretical understanding of the chaotic nature of the atmosphere coupled to the Earth’s global topography.

  6. Impact of Acid Attack on the Shear Behaviour of a Carbonate Rock Joint

    NASA Astrophysics Data System (ADS)

    Nouailletas, O.; Perlot, C.; Rivard, P.; Ballivy, G.; La Borderie, C.

    2017-06-01

    The mechanical behaviour of structural discontinuities in rock mass is a key element of the stability analysis in civil engineering, petroleum engineering and mining engineering. In this paper, the mechanical analysis is coupled with the acidic attack of a rock joint associated with leakage of CO2 through a geological fault in the context of carbon sequestration. Experiments were conducted at the laboratory scale to assess the shear behaviour of degraded joint: direct shear tests were performed on rock joints that have been previously immersed into water or into an acidic solution (pH 0.2). The shear behaviour of joints is governed by the roughness of its walls: the parameters Z2, Z3, Z4 and RL characterize the rough surfaces. They are calculated from the scans of joint surfaces after and before immersion. Their comparison pointed out a slight impact of the acidic attack. However, the results of the direct shear tests show significant modifications in the shear behaviour for the degraded joints: the tangential stress peak disappears, the tangential stiffness decreases in the stress/displacement curve, and the contraction increases, the dilation angle decreases in the dilation curve. Acid attack has a greater impact on the mechanical properties of the asperities than their geometric characteristics. The results of this study will be used to improve chemo-mechanical modelling to better simulate with higher accuracy the fault stability in different cases of civil engineering, petroleum engineering and mining engineering.

  7. Finishing of advanced ceramic balls for bearing applications by magnetic float polishing (MFP) involving fine polishing followed by chemo-mechanical polishing (CMP)

    NASA Astrophysics Data System (ADS)

    Jiang, Ming

    Scope and method of study. This investigation deals with the development of science and technology of finishing advanced ceramics, such as Sisb3Nsb4 balls for bearing applications by magnetic float polishing (MFP) technology. Experimental design and analysis based on Taguchi method are applied to determine the optimum processing conditions for improving the surface quality in fine mechanical polishing by MFP technology. Polishing with various abrasives, different operating conditions, and polishing environments for Sisb3Nsb4 bearing balls have been investigated. Fundamental mechanisms of chemo-mechanical polishing (CMP) have been studied based on thermodynamic and kinetic analysis. Findings and conclusions. The methodology, involved mechanical polishing followed by CMP for finishing of Sisb3Nsb4 balls from the as-received condition to a sphericity of 0.15 mum and surface finish of Ra 4 nm by MFP technology has been developed. It takes about 20 hours to finish a batch of balls compared to a range of several weeks to several months by conventional grinding and polishing technology. High material removal rates (1 mum/min) with minimal subsurface damage are possible by mechanical polishing with harder abrasives such as Bsb4C or SiC in MFP. CeOsb2 and ZrOsb2 are found to be most effective abrasives followed by Fesb2Osb3 and Crsb2Osb3 for CMP of Sisb3Nsb4. CMP is found to be particularly effective in a water-based environment. There are similarities between polishing glass and polishing Sisb3Nsb4 workmaterial including the role of water, polishing environment, and chemical effectiveness and mechanical hardness of abrasive for effective polishing.

  8. Chemo-mechanical modification of cottonwood for Pb(2+) removal from aqueous solutions: Sorption mechanisms and potential application as biofilter in drip-irrigation.

    PubMed

    Mosa, Ahmed; El-Ghamry, Ayman; Trüby, Peter; Omar, Mahmoud; Gao, Bin; Elnaggar, Abdelhamid; Li, Yuncong

    2016-10-01

    Using biomass (e.g. crop residues) and its derivatives as biosorbents have been recognized as an eco-friendly technique for wastewater decontamination. In this study, mechanically modified cottonwood was further activated with KOH to improve its sorption of Pb(2+). In addition, its potential as a biofilter to safeguard radish (Raphanus sativus, L.) against Pb-stress was evaluated in a gravity-fed drip irrigation system. Physiochemical properties of the chemo-mechanically activated cottonwood (CMACW) and the mechanically activated cottonwood (MACW) before and after sorption process were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), digital selected-area electron diffraction (SAED) and Fourier transform infrared spectroscopy (FTIR). After activation, several sorption mechanisms (i.e. precipitation, electrostatic outer- and inner-sphere complexation) were responsible for the higher sorption capacity of CMACW as compared with MACW (8.55 vs. 7.28 mg g(-1)). Sorption kinetics and isotherms fitted better with the pseudo-second-order and Langmuir models as compared with the pseudo-first-order and Freundlich models, respectively. In the gravity-fed drip irrigation system, the CMACW biofilter reduced the accumulation of Pb in radish roots and shoots and avoided reaching the toxic limits in some cases. Soil types had a significant effect on Pb(2+) bioavailability because of the difference in sorption ability. Findings from this study showed that CMACW biofilter can be used as a safeguard for wastewater irrigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Exploring Early Angiosperm Fire Feedbacks using Coupled Experiments and Modelling Approaches to Estimate Cretaceous Palaeofire Behaviour

    NASA Astrophysics Data System (ADS)

    Belcher, Claire; Hudpsith, Victoria

    2016-04-01

    Using the fossil record we are typically limited to exploring linkages between palaeoecological changes and palaeofire activity by assessing the abundance of charcoals preserved in sediments. However, it is the behaviour of fires that primarily governs their ecological effects. Therefore, the ability to estimate variations in aspects of palaeofire behaviour such as palaeofire intensity and rate of spread would be of key benefit toward understanding the coupled evolutionary history of ecosystems and fire. The Cretaceous Period saw major diversification in land plants. Previously, conifers (gymnosperms) and ferns (pteridophytes) dominated Earth's ecosystems until flowering plants (angiosperms) appear in the fossil record of the Early Cretaceous (~135Ma). We have created surface fire behaviour estimates for a variety of angiosperm invasion scenarios and explored the influence of Cretaceous superambient atmospheric oxygen levels on the fire behaviour occurring in these new Cretaceous ecosystems. These estimates are then used to explore the hypothesis that the early spread of the angiosperms was promoted by the novel fire regimes that they created. In order to achieve this we tested the flammability of Mesozoic analogue fuel types in controlled laboratory experiments using an iCone calorimeter, which measured the ignitability as well as the effective heat of combustion of the fuels. We then used the BehavePlus fire behaviour modelling system to scale up our laboratory results to the ecosystem scale. Our results suggest that fire-angiosperm feedbacks may have occurred in two phases: The first phase being a result of weedy angiosperms providing an additional easily ignitable fuel that enhanced both the seasonality and frequency of surface fires. In the second phase, the addition of shrubby understory fuels likely expanded the number of ecosystems experiencing more intense surface fires, resulting in enhanced mortality and suppressed post-fire recruitment of gymnosperms

  10. Denominational affiliation and fertility behaviour in an African context: an examination of couple data from Ghana.

    PubMed

    Gyimah, Stephen Obeng; Takyi, Baffour; Tenkorang, Eric Yeboah

    2008-05-01

    Although studies have examined religious differences in fertility in sub-Saharan Africa, it is argued in this paper that using women-only sample data may be conceptually problematic in patriarchal African societies where the influence of husbands on their wives' reproductive preferences is paramount. The present study contributes to this discourse by examining the relationship between religion and fertility behaviour using matched-couple data from Ghana. Guided by the 'religious values' and 'characteristics' hypotheses, the results indicate significant religious differences in fertility. Compared with Traditionalists, Christians and Muslims have lower fertility, albeit these differences diminish significantly after controlling for socioeconomic variables. The impact of wife's religious denomination on marital fertility is attenuated after controlling for husband's religious affiliation. Also, fertility was found to be higher if couples belong to the same faith compared with those of different faiths.

  11. A cell-based computational model of early embryogenesis coupling mechanical behaviour and gene regulation

    PubMed Central

    Delile, Julien; Herrmann, Matthieu; Peyriéras, Nadine; Doursat, René

    2017-01-01

    The study of multicellular development is grounded in two complementary domains: cell biomechanics, which examines how physical forces shape the embryo, and genetic regulation and molecular signalling, which concern how cells determine their states and behaviours. Integrating both sides into a unified framework is crucial to fully understand the self-organized dynamics of morphogenesis. Here we introduce MecaGen, an integrative modelling platform enabling the hypothesis-driven simulation of these dual processes via the coupling between mechanical and chemical variables. Our approach relies upon a minimal ‘cell behaviour ontology' comprising mesenchymal and epithelial cells and their associated behaviours. MecaGen enables the specification and control of complex collective movements in 3D space through a biologically relevant gene regulatory network and parameter space exploration. Three case studies investigating pattern formation, epithelial differentiation and tissue tectonics in zebrafish early embryogenesis, the latter with quantitative comparison to live imaging data, demonstrate the validity and usefulness of our framework. PMID:28112150

  12. Coupling metabolism and chemotaxis-dependent behaviours by energy taxis receptors.

    PubMed

    Alexandre, Gladys

    2010-08-01

    Bacteria have evolved the ability to monitor changes in various physico-chemical parameters and to adapt their physiology and metabolism by implementing appropriate cellular responses to these changes. Energy taxis is a metabolism-dependent form of taxis and is the directed movement of motile bacteria in gradients of physico-chemical parameters that affect metabolism. Energy taxis has been described in diverse bacterial species and several dedicated energy sensors have been identified. The molecular mechanism of energy taxis has not been studied in as much detail as chemotaxis, but experimental evidence indicates that this behaviour differs from metabolism-independent taxis only by the presence of dedicated energy taxis receptors. Energy taxis receptors perceive changes in energy-related parameters, including signals related to the redox and/or intracellular energy status of the cell. The best-characterized energy taxis receptors are those that sense the redox state of the electron transport chain via non-covalently bound FAD cofactors. Other receptors shown to mediate energy taxis lack any recognizable redox cofactor or conserved energy-sensing motif, and some have been suggested to monitor changes in the proton motive force. The exact energy-sensing mechanism(s) involved are yet to be elucidated for most of these energy sensors. By monitoring changes in energy-related parameters, energy taxis receptors allow cells to couple motility behaviour with metabolism under diverse environmental conditions. Energy taxis receptors thus provide fruitful models to decipher how cells integrate sensory behaviours with metabolic activities.

  13. Saturation behaviour of colloidal PbSe quantum dot exciton emission coupled into silicon photonic circuits.

    PubMed

    Foell, Charles A; Schelew, Ellen; Qiao, Haijun; Abel, Keith A; Hughes, Stephen; van Veggel, Frank C J M; Young, Jeff F

    2012-05-07

    We report coupling of the excitonic photon emission from photoexcited PbSe colloidal quantum dots (QDs) into an optical circuit that was fabricated in a silicon-on-insulator wafer using a CMOS-compatible process. The coupling between excitons and sub-μm sized silicon channel waveguides was mediated by a photonic crystal microcavity. The intensity of the coupled light saturates rapidly with the optical excitation power. The saturation behaviour was quantitatively studied using an isolated photonic crystal cavity with PbSe QDs site-selectively located at the cavity mode antinode position. Saturation occurs when a few μW of continuous wave HeNe pump power excites the QDs with a Gaussian spot size of 2 μm. By comparing the results with a master equation analysis that rigorously accounts for the complex dielectric environment of the QD excitons, the saturation is attributed to ground state depletion due to a non-radiative exciton decay channel with a trap state lifetime ~ 3 μs.

  14. Perpetual postponers? Women's, men's and couple's fertility intentions and subsequent fertility behaviour.

    PubMed

    Berrington, Ann

    2004-01-01

    In this article data from the British Household Panel Study (BHPS) are used to analyse gender differences in fertility intentions, and the correspondence between fertility intentions and subsequent fertility behaviour. By exploiting couple-level data, we examine whether partners have conflicting preferences for future fertility. Focusing on women who remain childless in their thirties we look at socio-demographic factors related to the intention to remain childless, or to start a family later on in life. By following up women over time, the characteristics of women who go on to have a child later on in life are considered. The importance of having a partner and the fertility intention of that partner in predicting whether a birth will occur are also examined.

  15. Coupling submesoscale physics to seabirds behaviour at the ocean-atmosphere interface

    NASA Astrophysics Data System (ADS)

    De Monte, S.; Cotté, C.; d'Ovidio, F.; Lévy, M.; Le Corre, M.; Weimerskirch, H.

    2012-04-01

    During their journeys, seabirds are faced to environmental heterogeneity of the scale of tens of Kms in extension and of days in duration, that are induced in the open ocean by mesoscale and submesoscale turbulence. We combine tracking of frigatebirds in the Mozambique channel - available for the first time with 3-D resolution - and multisatellite-based nonlinear diagnostics to inquire how birds respond to the coupled ocean-atmosphere physics. Birds behaviour along their flight trajectory are categorized in 5 classes of vertical displacement, e.g. slow or fast descents, and are superimposed with the submesoscale structures obtained by a Lagrangian reanalysis or remote-sensing measures. We show that frigatebirds modify their behaviour at such scale over and outside transport and thermal fronts. We suggest that birds colocalization with structures generated by horizontal transport is a consequence of their quest for food (preferentially located on thermal fronts) but also for upward vertical wind. Our multidisciplinary method can be applied to forthcoming high-resolution animal tracking data and contribute to elucidate the response of marine ecosystems to environmental change.

  16. Diffraction aperture non-ideal behaviour of air coupled transducers array elements designed for NDT.

    PubMed

    Prego Borges, J L; Montero de Espinosa, F; Salazar, J; Garcia-Alvarez, J; Chávez, J A; Turó, A; Garcia-Hernandez, M J

    2006-12-22

    Air coupled piezoelectric ultrasonic array transducers are a novel tool that could lead to interesting advances in the area of non-contact laminar material testing using Lamb wave's propagation techniques. A key issue on the development of such transducers is their efficient coupling to air media (impedance mismatch between the piezoelectric material and air is 90 dB or more). Adaptation layers are used in order to attain good matching and avoid possible serious signal degradation. However, the introduction of these matching layers modify the transducer surface behaviour and, consequently, radiation characteristics are altered, making the usual idealization criteria (of uniform surface movement) adopted for field simulation purposes inaccurate. In our system, we have a concave linear-array transducer of 64 elements (electrically coupled by pairs) working at 0.8 MHz made of PZ27 rectangular piezoceramics (15 mm x 0.3 mm) with two matching layers made of polyurethane and porous cellulose bonded on them. Experimental measurements of the acoustic aperture of single excited array elements have shown an increment on the geometrical dimensions of its active surface. A sub-millimeter vibrometer laser scan has revealed an extension of the aperture beyond the supposed physical single array element dimensions. Non-uniform symmetric apodized velocity surface vibration amplitude profile with a concave delay contour indicates the presumed existence of travelling wave phenomena over the surface of the outer array matching layer. Also, asymptotic propagation velocities around 2500 m/s and attenuation coefficient between 15 and 20 dB/mm has been determined for the travelling waves showing clear tendencies. Further comparisons between the experimental measurements of single array element field radiation diagram and simulated equivalent aperture counterpart reveal good agreement versus the ideal (uniform displaced) rectangular aperture. For this purpose an Impulse Response Method

  17. Static and dynamic strain coupling behaviour of ferroic and multiferroic perovskites from resonant ultrasound spectroscopy.

    PubMed

    Carpenter, M A

    2015-07-08

    Resonant ultrasound spectroscopy (RUS) provides a window on the pervasive influence of strain coupling at phase transitions in perovskites through determination of elastic and anelastic relaxations across wide temperature intervals and with the application of external fields. In particular, large variations of elastic constants occur at structural, ferroelectric and electronic transitions and, because of the relatively long interaction length provided by strain fields in a crystal, Landau theory provides an effective formal framework for characterizing their form and magnitude. At the same time, the Debye equations provide a robust description of dynamic relaxational processes involving the mobility of defects which are coupled with strain. Improper ferroelastic transitions driven by octahedral tilting in KMnF3, LaAlO3, (Ca,Sr)TiO3, Sr(Ti,Zr)O3 and BaCeO3 are accompanied by elastic softening of tens of % and characteristic patterns of acoustic loss due to the mobility of twin walls. RUS data for ferroelectrics and ferroelectric relaxors, including BaTiO3, (K,Na)NbO3,Pb(Mg1/3Nb2/3)O3 (PMN), Pb(Sc1/2Ta1/2)O3 (PST), (Pb(Zn1/3Nb2/3)O3)0.955(PbTiO3)0.045 (PZN-PT) and (Pb(In1/2Nb1/2)O3)0.26(Pb(Mg1/3Nb2/3)O3)0.44(PbTiO3)0.30 (PIN-PMN-PT) show similar patterns of softening and attenuation but also have precursor softening associated with the development of polar nano regions. Defect-induced ferroelectricity occurs in KTaO3, without the development of long range ordering. By way of contrast, spin-lattice coupling is much more variable in strength, as reflected in a greater range of softening behaviour for Pr0.48Ca0.52MnO3 and Sm0.6Y0.4MnO3 as well as for the multiferroic perovskites EuTiO3,BiFeO3, Bi0.9Sm0.1FeO3, Bi0.9Nd0.1FeO3, (BiFeO3)0.64(CaFeO2.5)0.36, (Pb(Fe0.5Ti0.5)O3)0.4(Pb(Zr0.53Ti0.47)O3)0.6. A characteristic feature of transitions in which there is a significant Jahn-Teller component is softening as the transition point is approached from above, as illustrated by

  18. Static and dynamic strain coupling behaviour of ferroic and multiferroic perovskites from resonant ultrasound spectroscopy

    NASA Astrophysics Data System (ADS)

    Carpenter, M. A.

    2015-07-01

    Resonant ultrasound spectroscopy (RUS) provides a window on the pervasive influence of strain coupling at phase transitions in perovskites through determination of elastic and anelastic relaxations across wide temperature intervals and with the application of external fields. In particular, large variations of elastic constants occur at structural, ferroelectric and electronic transitions and, because of the relatively long interaction length provided by strain fields in a crystal, Landau theory provides an effective formal framework for characterizing their form and magnitude. At the same time, the Debye equations provide a robust description of dynamic relaxational processes involving the mobility of defects which are coupled with strain. Improper ferroelastic transitions driven by octahedral tilting in KMnF3, LaAlO3, (Ca,Sr)TiO3, Sr(Ti,Zr)O3 and BaCeO3 are accompanied by elastic softening of tens of % and characteristic patterns of acoustic loss due to the mobility of twin walls. RUS data for ferroelectrics and ferroelectric relaxors, including BaTiO3, (K,Na)NbO3,Pb(Mg1/3Nb2/3)O3 (PMN), Pb(Sc1/2Ta1/2)O3 (PST), (Pb(Zn1/3Nb2/3)O3)0.955(PbTiO3)0.045 (PZN-PT) and (Pb(In1/2Nb1/2)O3)0.26(Pb(Mg1/3Nb2/3)O3)0.44(PbTiO3)0.30 (PIN-PMN-PT) show similar patterns of softening and attenuation but also have precursor softening associated with the development of polar nano regions. Defect-induced ferroelectricity occurs in KTaO3, without the development of long range ordering. By way of contrast, spin-lattice coupling is much more variable in strength, as reflected in a greater range of softening behaviour for Pr0.48Ca0.52MnO3 and Sm0.6Y0.4MnO3 as well as for the multiferroic perovskites EuTiO3,BiFeO3, Bi0.9Sm0.1FeO3, Bi0.9Nd0.1FeO3, (BiFeO3)0.64(CaFeO2.5)0.36, (Pb(Fe0.5Ti0.5)O3)0.4(Pb(Zr0.53Ti0.47)O3)0.6. A characteristic feature of transitions in which there is a significant Jahn-Teller component is softening as the transition point is approached from above, as illustrated by

  19. Multiple health behaviours among mothers and partners in England: Clustering, social patterning and intra-couple concordance.

    PubMed

    Graham, Hilary; Hutchinson, Jayne; Law, Catherine; Platt, Lucinda; Wardle, Heather

    2016-12-01

    Research on multiple health behaviours is increasing but little is known about parental behaviours and how they covary. Our study investigates cigarette smoking, alcohol intake, fruit and vegetable (F&V) consumption and physical activity among mothers and co-resident partners in England. Using the UK Household Longitudinal Study, we examined (i) clustering of health behaviours using observed-expected ratios and latent class analysis (ii) socio-demographic correlates of the derived latent classes and (iii) intra-couple concordance of individual health behaviours and their latent classes. We identified five latent classes for mothers and partners: Never smoked drinkers (28% of mothers; 29% of partners), Abstainers (25%; 17%), Drinkers and ex-smokers (19%; 26%), Unhealthy low frequency drinkers (18%; 16%) and Unhealthiest behaviour group (11%; 12%). These had distinctive social profiles. Never smoked drinkers were more likely than those in other groups to be white and socially advantaged: married, older, and with higher educational qualifications and incomes. Abstainers were non-smokers who never or occasionally drank, and were disproportionately drawn from ethnic minority groups and middle/lower income families. Drinkers and ex-smokers were the most physically active group and were more likely to be socially advantaged. Unhealthy low frequency drinkers were more likely to be disadvantaged and have a limiting long-standing illness. The Unhealthiest behaviour group had the highest proportion of smokers, heavy smokers and binge drinkers and the lowest F&V intake and physical activity levels. They were largely white and socially disadvantaged: younger, non-married and with lower educational levels. Mothers and their partners typically shared the same risk behaviours, and 44 per cent of partners and mothers belonged to the same latent class. Our findings point to the potential for a broadening of research and policy perspectives, from separate behaviours to combinations

  20. Effect of Couples Counselling on Reported HIV Risk Behaviour among HIV Serodiscordant Couples by ART Use, HIV Status and Gender in Rural Uganda

    PubMed Central

    King, Rachel; Min, Jeong; Birungi, Josephine; Nyonyintono, Maureen; Muldoon, Katherine A.; Khanakwa, Sarah; Kaleebu, Pontiano; Moore, David M.

    2015-01-01

    Background We examined several measures of self-reported HIV risk behaviour in mutually disclosed sero-discordant couples over time to see if a couples counselling intervention was associated with changes in these behaviors. Methods We analysed data from a prospective cohort study of HIV sero-discordant couples in Jinja, Uganda collected between June 2009 and December 2011. Participants received couples counselling, at 3-monthly intervals. We examined trends in reported condom-use, number of concurrent sexual partners, knowledge of HIV serostatus of concurrent partners and condom use of concurrent partners using Generalized Estimating Equation models, comparing responses at study enrollment with responses at six, 12 18 and 24 months of follow-up. Results A total of 586 couples were enrolled and the female member was HIV positive in 255 (44%) of them. The median age for female participants was 35 years and 42 years for men. Reported condom use at last sex with spouse increased over time (p<0.001) with the largest increases found among couples where the positive participant never received ART during the study(an increase from 68.8% at enrollment to 97.1% at 24 months). Male participants reported reductions in the number of concurrent sexual partners (p<0.001), increase in the knowledge of the HIV serostatus of these partners (p = 0.001) and a trend towards improved condom-use among non-primary partners (p = 0.070). Reported reduced risky behaviors did not wane over the study period. Conclusion Couples counselling resulted in increased condom use among all participants and among men the intervention resulted in reductions in risk behaviour with concurrent sexual partners. Routine counselling for serodiscordant couples should be integrated in routine ART care programs. PMID:26384103

  1. Self-Organized Criticality, Plasticity and Sensorimotor Coupling. Explorations with a Neurorobotic Model in a Behavioural Preference Task

    PubMed Central

    Aguilera, Miguel; Barandiaran, Xabier E.; Bedia, Manuel G.; Seron, Francisco

    2015-01-01

    During the last two decades, analysis of 1/ƒ noise in cognitive science has led to a considerable progress in the way we understand the organization of our mental life. However, there is still a lack of specific models providing explanations of how 1/ƒ noise is generated in coupled brain-body-environment systems, since existing models and experiments typically target either externally observable behaviour or isolated neuronal systems but do not address the interplay between neuronal mechanisms and sensorimotor dynamics. We present a conceptual model of a minimal neurorobotic agent solving a behavioural task that makes it possible to relate mechanistic (neurodynamic) and behavioural levels of description. The model consists of a simulated robot controlled by a network of Kuramoto oscillators with homeostatic plasticity and the ability to develop behavioural preferences mediated by sensorimotor patterns. With only three oscillators, this simple model displays self-organized criticality in the form of robust 1/ƒ noise and a wide multifractal spectrum. We show that the emergence of self-organized criticality and 1/ƒ noise in our model is the result of three simultaneous conditions: a) non-linear interaction dynamics capable of generating stable collective patterns, b) internal plastic mechanisms modulating the sensorimotor flows, and c) strong sensorimotor coupling with the environment that induces transient metastable neurodynamic regimes. We carry out a number of experiments to show that both synaptic plasticity and strong sensorimotor coupling play a necessary role, as constituents of self-organized criticality, in the generation of 1/ƒ noise. The experiments also shown to be useful to test the robustness of 1/ƒ scaling comparing the results of different techniques. We finally discuss the role of conceptual models as mediators between nomothetic and mechanistic models and how they can inform future experimental research where self-organized critically includes

  2. Self-organized criticality, plasticity and sensorimotor coupling. Explorations with a neurorobotic model in a behavioural preference task.

    PubMed

    Aguilera, Miguel; Barandiaran, Xabier E; Bedia, Manuel G; Seron, Francisco

    2015-01-01

    During the last two decades, analysis of 1/ƒ noise in cognitive science has led to a considerable progress in the way we understand the organization of our mental life. However, there is still a lack of specific models providing explanations of how 1/ƒ noise is generated in coupled brain-body-environment systems, since existing models and experiments typically target either externally observable behaviour or isolated neuronal systems but do not address the interplay between neuronal mechanisms and sensorimotor dynamics. We present a conceptual model of a minimal neurorobotic agent solving a behavioural task that makes it possible to relate mechanistic (neurodynamic) and behavioural levels of description. The model consists of a simulated robot controlled by a network of Kuramoto oscillators with homeostatic plasticity and the ability to develop behavioural preferences mediated by sensorimotor patterns. With only three oscillators, this simple model displays self-organized criticality in the form of robust 1/ƒ noise and a wide multifractal spectrum. We show that the emergence of self-organized criticality and 1/ƒ noise in our model is the result of three simultaneous conditions: a) non-linear interaction dynamics capable of generating stable collective patterns, b) internal plastic mechanisms modulating the sensorimotor flows, and c) strong sensorimotor coupling with the environment that induces transient metastable neurodynamic regimes. We carry out a number of experiments to show that both synaptic plasticity and strong sensorimotor coupling play a necessary role, as constituents of self-organized criticality, in the generation of 1/ƒ noise. The experiments also shown to be useful to test the robustness of 1/ƒ scaling comparing the results of different techniques. We finally discuss the role of conceptual models as mediators between nomothetic and mechanistic models and how they can inform future experimental research where self-organized critically includes

  3. Using stability analyses to predict dynamic behaviour of self-oscillating polymer gels

    NASA Astrophysics Data System (ADS)

    Palkar, Vaibhav; Srivastava, Gaurav; Kuksenok, Olga; Balazs, Anna C.; Dayal, Pratyush

    2015-03-01

    Use of chemo-mechanical transduction to produce locomotion is one of the significant characteristics of biological systems. Polymer gels, intrinsically powered by oscillatory Belousov-Zhabotinsky (BZ) reaction, are biomimetic materials that exhibit rhythmic self-sustained mechanical oscillations by chemo-mechanical transduction. Via simulations, based on the 3D gel lattice spring model, we have successfully captured the dynamic behaviour of BZ gels. We have demonstrated that it is possible to direct the movement of BZ gels along complex paths, guiding them to bend, reorient and turn. From a mathematical perspective, the oscillations in the BZ gels occur when the gel's steady states loose stability by virtue of Hopf bifurcations (HB). Through the use of stability analyses, we predict the conditions under which gel switches from stationary to oscillatory mode and vice versa. In addition, we characterize the nature of HB and also identify other types of bifurcations that play a critical role in governing the dynamic behaviour of BZ gels. Also, we successfully predict the frequency of chemo-mechanical oscillations and characterize its dependency on the model parameters. Our approach not only allows us to establish optimal conditions for the motion of BZ gels, but also can be used to design other dynamical systems. IIT Gandhinagar and DST-SERB for funding.

  4. Couples' attributions about behaviours modulated by hearing impairment: links with relationship satisfaction.

    PubMed

    Anderson, Donnah L; Noble, William

    2005-04-01

    The aim of the study was to examine the link between the nature of attributions made by partners about behaviours modulated by hearing loss, and overall relationship satisfaction. Forty-three hearing-impaired males and 23 hearing-impaired females together with their partners, each rated the hearing-impaired person's hearing ability, their own relationship satisfaction, and their attributions for hypothetical behaviours typically associated with impaired hearing. Attributions covered perceived causes of behaviour and perceived responsibility. The extent to which the behaviours typically associated with impaired hearing, were attributed to personal causes and responsibilities was inversely correlated with relationship satisfaction. Female partners (more than male partners, or females with impaired hearing) made attributions that accentuated the unpleasant implications of behaviour. Where attributions and ratings of degree of hearing loss were greater in partners than in the person with the loss, relationship satisfaction was lower. Implications for rehabilitation counselling are discussed.

  5. Gpr176 is a Gz-linked orphan G-protein-coupled receptor that sets the pace of circadian behaviour

    PubMed Central

    Doi, Masao; Murai, Iori; Kunisue, Sumihiro; Setsu, Genzui; Uchio, Naohiro; Tanaka, Rina; Kobayashi, Sakurako; Shimatani, Hiroyuki; Hayashi, Hida; Chao, Hsu-Wen; Nakagawa, Yuuki; Takahashi, Yukari; Hotta, Yunhong; Yasunaga, Jun-ichirou; Matsuoka, Masao; Hastings, Michael H.; Kiyonari, Hiroshi; Okamura, Hitoshi

    2016-01-01

    G-protein-coupled receptors (GPCRs) participate in a broad range of physiological functions. A priority for fundamental and clinical research, therefore, is to decipher the function of over 140 remaining orphan GPCRs. The suprachiasmatic nucleus (SCN), the brain's circadian pacemaker, governs daily rhythms in behaviour and physiology. Here we launch the SCN orphan GPCR project to (i) search for murine orphan GPCRs with enriched expression in the SCN, (ii) generate mutant animals deficient in candidate GPCRs, and (iii) analyse the impact on circadian rhythms. We thereby identify Gpr176 as an SCN-enriched orphan GPCR that sets the pace of circadian behaviour. Gpr176 is expressed in a circadian manner by SCN neurons, and molecular characterization reveals that it represses cAMP signalling in an agonist-independent manner. Gpr176 acts independently of, and in parallel to, the Vipr2 GPCR, not through the canonical Gi, but via the unique G-protein subclass Gz. PMID:26882873

  6. Behavioural interventions to reduce sexual risk for HIV in heterosexual couples: a meta-analysis.

    PubMed

    LaCroix, Jessica M; Pellowski, Jennifer A; Lennon, Carter A; Johnson, Blair T

    2013-12-01

    The current study was conducted to synthesise evaluations of couple-based HIV prevention interventions, assess the efficacy of these interventions in reducing sexual risk, and identify moderators of intervention efficacy. A comprehensive literature search identified 29 interventions (22 reports; N=5168 couples) that met the inclusion criteria, including enrolment of both members of a heterosexual couple, measurement of condom use at baseline and follow-up, and sufficient statistical information to calculate effect sizes. Effect sizes were analysed using fixed-effects and random-effects assumptions; factors related to intervention efficacy were identified using metaregression. Overall, there were significant increases in condom use from baseline to follow-up (d+=0.78, 95% CI 0.48 to 1.09) and significant decreases in partner concurrency (d+=0.37, 95% CI 0.13 to 0.60). Condom use increased to a greater extent when studies were conducted toward the beginning of the epidemic, were located in countries scoring lower on the Human Development Index, enrolled serodiscordant couples, and delivered intervention content in multiple contexts. Couples who had been together longer, reported higher incidence of sexually transmitted infection, were provided voluntary counselling and testing, and provided outcome measures during face-to-face interviews also reported larger increases in condom use. Couple-based interventions are efficacious in reducing unprotected sex within the context of romantic relationships. Future research should continue to improve risk reduction for couples.

  7. Model coupling methodology for thermo-hydro-mechanical-chemical numerical simulations in integrated assessment of long-term site behaviour

    NASA Astrophysics Data System (ADS)

    Kempka, Thomas; De Lucia, Marco; Kühn, Michael

    2015-04-01

    The integrated assessment of long-term site behaviour taking into account a high spatial resolution at reservoir scale requires a sophisticated methodology to represent coupled thermal, hydraulic, mechanical and chemical processes of relevance. Our coupling methodology considers the time-dependent occurrence and significance of multi-phase flow processes, mechanical effects and geochemical reactions (Kempka et al., 2014). Hereby, a simplified hydro-chemical coupling procedure was developed (Klein et al., 2013) and validated against fully coupled hydro-chemical simulations (De Lucia et al., 2015). The numerical simulation results elaborated for the pilot site Ketzin demonstrate that mechanical reservoir, caprock and fault integrity are maintained during the time of operation and that after 10,000 years CO2 dissolution is the dominating trapping mechanism and mineralization occurs on the order of 10 % to 25 % with negligible changes to porosity and permeability. De Lucia, M., Kempka, T., Kühn, M. A coupling alternative to reactive transport simulations for long-term prediction of chemical reactions in heterogeneous CO2 storage systems (2014) Geosci Model Dev Discuss 7:6217-6261. doi:10.5194/gmdd-7-6217-2014. Kempka, T., De Lucia, M., Kühn, M. Geomechanical integrity verification and mineral trapping quantification for the Ketzin CO2 storage pilot site by coupled numerical simulations (2014) Energy Procedia 63:3330-3338, doi:10.1016/j.egypro.2014.11.361. Klein E, De Lucia M, Kempka T, Kühn M. Evaluation of longterm mineral trapping at the Ketzin pilot site for CO2 storage: an integrative approach using geo-chemical modelling and reservoir simulation. Int J Greenh Gas Con 2013; 19:720-730. doi:10.1016/j.ijggc.2013.05.014.

  8. Nonlinear dynamic behaviour of a rotor-foundation system coupled through passive magnetic bearings with magnetic anisotropy - Theory and experiment

    NASA Astrophysics Data System (ADS)

    Enemark, Søren; Santos, Ilmar F.

    2016-02-01

    In this work, the nonlinear dynamic behaviour of a vertical rigid rotor interacting with a flexible foundation by means of two passive magnetic bearings is quantified and evaluated. The quantification is based on theoretical and experimental investigation of the non-uniformity (anisotropy) of the magnetic field and the weak nonlinearity of the magnetic forces. Through mathematical modelling the nonlinear equations of motion are established for describing the shaft and bearing housing lateral dynamics coupled via the nonlinear and non-uniform magnetic forces. The equations of motion are solved in the frequency domain by the methods of Finite Difference and pseudo-arclength continuation. The theoretical findings are validated against experiments carried out using a dedicated test-rig and a special device for characterisation of the magnetic anisotropy. The characterisation of the magnetic anisotropy shows that it can be quantified as magnetic eccentricities having an amplitude and a phase, which result in linear and parametric excitation. The magnetic eccentricities are also determined using the steady-state response of the rotor-bearing system due to forcing from the magnetic anisotropies and several levels of mass imbalance. Discrepancies in the results from the two methods in terms of magnetic eccentricity magnitude are due to additional geometric eccentricities in the shaft. The steady-state system response shows clear nonlinear phenomena, e.g. bent resonance peaks, jump phenomena and nonlinear cross-coupling between the two orthogonal directions, especially during counter-phase motion between shaft and bearings. The clear nonlinear behaviour is facilitated by the lack of damping resulting in relatively large vibrations. The overall nonlinear dynamic behaviour is well captured by the theoretical model, thereby validating the modelling approach.

  9. A 3D skeletal muscle model coupled with active contraction of muscle fibres and hyperelastic behaviour.

    PubMed

    Tang, C Y; Zhang, G; Tsui, C P

    2009-05-11

    This paper presents a three-dimensional finite element model of skeletal muscle which was developed to simulate active and passive non-linear mechanical behaviours of the muscle during lengthening or shortening under either quasi-static or dynamic condition. Constitutive relation of the muscle was determined by using a strain energy approach, while active contraction behaviour of the muscle fibre was simulated by establishing a numerical algorithm based on the concept of the Hill's three-element muscle model. The proposed numerical algorithm could be used to predict concentric, eccentric, isometric and isotonic contraction behaviours of the muscle. The proposed numerical algorithm and constitutive model for the muscle were derived and implemented into a non-linear large deformation finite element programme ABAQUS by using user-defined material subroutines. A number of scenarios have been used to demonstrate capability of the model for simulating both quasi-static and dynamic response of the muscle. Validation of the proposed model has been performed by comparing the simulated results with the experimental ones of frog gastrocenemius muscle deformation. The effects of the fusiform muscle geometry and fibre orientation on the stress and fibre stretch distributions of frog muscle during isotonic contraction have also been investigated by using the proposed model. The predictability of the present model for dynamic response of the muscle has been demonstrated by simulating the extension of a squid tentacle during a strike to catch prey.

  10. Behaviour of plate anchorage in plate-reinforced composite coupling beams.

    PubMed

    Lam, W Y; Li, Lingzhi; Su, R K L; Pam, H J

    2013-01-01

    As a new alternative design, plate-reinforced composite (PRC) coupling beam achieves enhanced strength and ductility by embedding a vertical steel plate into a conventionally reinforced concrete (RC) coupling beam. Based on a nonlinear finite element model developed in the authors' previous study, a parametric study presented in this paper has been carried out to investigate the influence of several key parameters on the overall performance of PRC coupling beams. The effects of steel plate geometry, span-to-depth ratio of beams, and steel reinforcement ratios at beam spans and in wall regions are quantified. It is found that the anchorage length of the steel plate is primarily controlled by the span-to-depth ratio of the beam. Based on the numerical results, a design curve is proposed for determining the anchorage length of the steel plate. The load-carrying capacity of short PRC coupling beams with high steel ratio is found to be controlled by the steel ratio of wall piers. The maximum shear stress of PRC coupling beams should be limited to 15 MPa.

  11. Behaviour of Plate Anchorage in Plate-Reinforced Composite Coupling Beams

    PubMed Central

    Lam, W. Y.; Li, Lingzhi; Su, R. K. L.; Pam, H. J.

    2013-01-01

    As a new alternative design, plate-reinforced composite (PRC) coupling beam achieves enhanced strength and ductility by embedding a vertical steel plate into a conventionally reinforced concrete (RC) coupling beam. Based on a nonlinear finite element model developed in the authors' previous study, a parametric study presented in this paper has been carried out to investigate the influence of several key parameters on the overall performance of PRC coupling beams. The effects of steel plate geometry, span-to-depth ratio of beams, and steel reinforcement ratios at beam spans and in wall regions are quantified. It is found that the anchorage length of the steel plate is primarily controlled by the span-to-depth ratio of the beam. Based on the numerical results, a design curve is proposed for determining the anchorage length of the steel plate. The load-carrying capacity of short PRC coupling beams with high steel ratio is found to be controlled by the steel ratio of wall piers. The maximum shear stress of PRC coupling beams should be limited to 15 MPa. PMID:24288465

  12. Modelling of the evaporation behaviour of particulate material for slurry nebulization inductively coupled plasma atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Merten, D.; Heitland, P.; Broekaert, J. A. C.

    1997-11-01

    This paper is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta, Part B (SAB). This hardcopy text, comprising the main body and an appendix, is accompanied by a disk with programs, data files and a brief manual. The main body discusses purpose, design principle and usage of the computer software for modelling the evaporation behaviour of particles in inductively coupled plasma atomic emission spectrometry (ICP-AES). Computer software has been developed in FORTRAN 77 language in order to simulate the evaporation behaviour of particles of refractory materials such as encountered in the analysis of advanced ceramic powders by slurry nebulization inductively coupled argon plasma atomic spectrometry. The program simulates the evaporation of single particles in the inductively coupled plasma and also enable it to calculate on the base of a given particle size distribution the evaporation behaviour of all the particles contained in a sample. In a so-called "intensity concept", the intensity is calculated as a function of the observation height in order to determine recovery rates for slurries compared with aqueous solutions. This yields a quick insight whether a calibration with aqueous solutions can be used for analysis of slurries of a given powder by slurry nebulization ICP-AES and also is a help in determining the optimal parameters for analyses of powders by means of slurry nebulization ICP-AES. Applications for the evaporation of Al 2O 3 and SiC powders document the usefulness of the model for the case of a 1.5 kW argon ICP of which the temperature at 8 mm above the load coil has been determined to be 6100 K. The model predicts the maximum particle size for SiC and Al 2O 3 that can be transported (10-15 μm) and evaporated for a given efficiency under given experimental conditions. For both Al 2O 3 and SiC, two ceramic powders of different grain size were investigated. The median particle sizes cover

  13. An experimental evaluation of the fully coupled hysteretic electro-mechanical behaviour of piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Butcher, Mark; Davino, Daniele; Giustiniani, Alessandro; Masi, Alessandro

    2016-04-01

    Piezoelectrics are the most commonly used of the multifunctional smart materials in industrial applications, because of their relatively low cost and ease of use in electric and electronic oriented applications. Nevertheless, while datasheets usually give just small signal quasi-static parameters, their full potential can only be exploited only if a full characterization is available because the maximum stroke or the higher piezo coupling coefficients are available at different electro-mechanical biases, where often small signal analysis is not valid. In this paper a method to get the quasi-static fully coupled characterization is presented. The method is tested on a commercial piezo actuator but can be extended to similar devices.

  14. Coupling system dynamics and contact behaviour: Modelling bearings subjected to environmental induced vibrations and ‘false brinelling’ degradation

    NASA Astrophysics Data System (ADS)

    Massi, Francesco; Rocchi, J.; Culla, A.; Berthier, Y.

    2010-05-01

    During the last decades the increase in power of mechanical systems and the demand for increasing service life leads mechanical components of a system to work in extreme conditions. Moreover, actual mechanical systems include surfaces in sliding contact that are subjected to wear if exposed to high vibration. In fact, the vibration of components in contact results in large oscillations of the local contact stresses, due to the local deformation of the components at the contact interfaces. To approach correctly tribological problems, the coupling between the scale of the mechanism (system dynamics) and the scale of the contact needs to be accounted for. This paper presents an analysis concerning the influence of the vibrations induced by aircraft engines on the contact stresses of rolling bearings of the bleed system valves. To study the wear, resulting from false brinelling at the contact surfaces between balls and races of the bearings, it is then necessary to determine the forces due to the system vibrations and acting at the bearing connections with the structure. In order to perform a numerical transient analysis of the system dynamics a nonlinear simplified model of the valve (mechanism scale) is developed. The model is validated by comparing the numerical results with experimental tests. The time behaviour of the global forces on the bearings, and the respective displacements between the contact surfaces, are then used as inputs for a finite element model of the bearings (contact scale). The model is used to calculate and analyze the behaviour in time of the local contact constraints between race and balls. This analysis, developed in the framework of a European project, is an example of the proposed general approach to contact problems, by coupling the analysis of the mechanism and contact scales.

  15. Divergence and ontogenetic coupling of larval behaviour and thermal reaction norms in three closely related butterflies.

    PubMed

    Berger, David; Friberg, Magne; Gotthard, Karl

    2011-01-22

    Genetic trade-offs such as between generalist-specialist strategies can be masked by changes in compensatory processes involving energy allocation and acquisition which regulation depends on the state of the individual and its ecological surroundings. Failure to account for such state dependence may thus lead to misconceptions about the trade-off structure and nature of constraints governing reaction norm evolution. Using three closely related butterflies, we first show that foraging behaviours differ between species and change remarkably throughout ontogeny causing corresponding differences in the thermal niches experienced by the foraging larvae. We further predicted that thermal reaction norms for larval growth rate would show state-dependent variation throughout development as a result of selection for optimizing feeding strategies in the respective foraging niches of young and old larvae. We found substantial developmental plasticity in reaction norms that was species-specific and reflected the different ontogenetic niche shifts. Any conclusions regarding constraints on performance curves or species-differentiation in thermal physiology depend on when reaction norms were measured. This demonstrates that standardized estimates at single points in development, or in general, allow variation in only one ecological dimension, may sometimes provide incomplete information on reaction norm constraints.

  16. The Interdependence of Adult Relationship Quality and Parenting Behaviours among African American and European Couples in Rural, Low-Income Communities

    PubMed Central

    Zvara, Bharathi J.; Mills-Koonce, W. Roger; Heilbron, Nicole; Clincy, Amanda; Cox, Martha J.

    2015-01-01

    The present study extends the spillover and crossover hypotheses to more carefully model the potential interdependence between parent–parent interaction quality and parent–child interaction quality in family systems. Using propensity score matching, the present study attempted to isolate family processes that are unique across African American and European American couples that are independent of other socio-demographic factors to further clarify how interparental relationships may be related to parenting in a rural, low-income sample. The Actor–Partner Interdependence Model (APIM), a statistical analysis technique that accounts for the interdependence of relationship data, was used with a sample of married and non-married cohabiting African American and European American couples (n = 82 dyads) to evaluate whether mothers' and fathers' observed parenting behaviours are related to their behaviours and their partner's behaviours observed in a couple problem-solving interaction. Findings revealed that interparental withdrawal behaviour, but not conflict behaviour, was associated with less optimal parenting for fathers but not mothers, and specifically so for African American fathers. Our findings support the notion of interdependence across subsystems within the family and suggest that African American fathers may be specifically responsive to variations in interparental relationship quality. PMID:26430390

  17. The Interdependence of Adult Relationship Quality and Parenting Behaviours among African American and European Couples in Rural, Low-Income Communities.

    PubMed

    Zvara, Bharathi J; Mills-Koonce, W Roger; Heilbron, Nicole; Clincy, Amanda; Cox, Martha J

    2015-01-01

    The present study extends the spillover and crossover hypotheses to more carefully model the potential interdependence between parent-parent interaction quality and parent-child interaction quality in family systems. Using propensity score matching, the present study attempted to isolate family processes that are unique across African American and European American couples that are independent of other socio-demographic factors to further clarify how interparental relationships may be related to parenting in a rural, low-income sample. The Actor-Partner Interdependence Model (APIM), a statistical analysis technique that accounts for the interdependence of relationship data, was used with a sample of married and non-married cohabiting African American and European American couples (n = 82 dyads) to evaluate whether mothers' and fathers' observed parenting behaviours are related to their behaviours and their partner's behaviours observed in a couple problem-solving interaction. Findings revealed that interparental withdrawal behaviour, but not conflict behaviour, was associated with less optimal parenting for fathers but not mothers, and specifically so for African American fathers. Our findings support the notion of interdependence across subsystems within the family and suggest that African American fathers may be specifically responsive to variations in interparental relationship quality.

  18. Coupling instantaneous energy-budget models and behavioural mode analysis to estimate optimal foraging strategy: an example with wandering albatrosses.

    PubMed

    Louzao, Maite; Wiegand, Thorsten; Bartumeus, Frederic; Weimerskirch, Henri

    2014-01-01

    How foragers move across the landscape to search for resources and obtain energy is a central issue in ecology. Direct energetic quantification of animal movements allows for testing optimal foraging theory predictions which assumes that animals forage so as to maximise net energy gain. Thanks to biologging advances, we coupled instantaneous energy-budget models and behavioural mode analysis to test optimal foraging theory predictions on wandering albatross Diomedea exulans during the brooding period. Specifically, the instantaneous energy-budget model considered the energetic balance (i.e., the difference between empirical energy gain data and modelled energy expenditure via heart rate values) along the trajectory of a given individual. Four stereotypic instantaneous behavioural modes were identified based on trajectory properties (e.g., speed and turning angle) by applying a new algorithm called Expectation Maximization Binary Clustering. Previous studies on this species have shown that foraging-in-flight is the optimal foraging strategy during the incubation period when albatrosses undertake long-distance movements but no specific foraging strategy has been determined for shorter foraging movements (e.g., brooding period). The output of our energy-budget model (measured as net energy gain) highlighted the potential optimality of alternative search strategies (e.g., sit-and-wait) during brooding, when birds may be subjected to specific energetic trade-offs and have to adapt their foraging strategies accordingly. However, not all birds showed this pattern, revealing the importance of considering individual variability in foraging strategies, as well as any switching among strategies, before drawing population-level generalizations. Finally, our study unveils the importance of considering fine scale activities to make realistic estimates of trip energy expenditure for flying birds at sea. The up-scaling of accurately measured fine-scale energy patterns is essential

  19. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  20. Signature effects of spin clustering and distribution of spin couplings on magnetization behaviour in Ni-Fe-Mo and Ni-Fe-W alloys.

    PubMed

    Banerjee, Mitali; Singh, Avinash; Majumdar, A K; Nigam, A K

    2011-08-03

    Spontaneous magnetization as a function of temperature is investigated for a number of disordered Ni-Fe-Mo and Ni-Fe-W alloys using superconducting quantum interference device magnetometry, with a focus on the low-T behaviour as well as the critical exponents associated with the magnetic phase transition. While the low-T magnetization is found to be well described by Bloch's T(3/2) law, extraordinary enhancements of the spin-wave parameter B and the reduced coefficient B(3/2) = BT(C)(3/2) are observed with increasing Fe dilution as compared to conventional 3d ferromagnets, whereas the critical amplitudes are found to decrease systematically. Recent locally self-consistent calculations of finite-temperature spin dynamics in a generic diluted magnet provide an understanding in terms of two distinct energy scales associated with weakly coupled bulk spins in the ferromagnetic matrix and strongly coupled cluster spins. In view of the similar behaviour observed in diluted magnetic semiconductors and other ferromagnetic alloys, it is proposed that these distinctive features corresponding to the three important temperature regimes provide macroscopic indicators of signature effects of spin clustering on the magnetization behaviour in disordered ferromagnets.

  1. A simple behaviour provides accuracy and flexibility in odour plume tracking--the robotic control of sensory-motor coupling in silkmoths.

    PubMed

    Ando, Noriyasu; Kanzaki, Ryohei

    2015-12-01

    Odour plume tracking is an essential behaviour for animal survival. A fundamental strategy for this is to move upstream and then across-stream. Male silkmoths, Bombyx mori, display this strategy as a pre-programmed sequential behaviour. They walk forward (surge) in response to the female sex pheromone and perform a zigzagging 'mating dance'. Though pre-programmed, the surge direction is modulated by bilateral olfactory input and optic flow. However, the nature of the interaction between these two sensory modalities and contribution of the resultant motor command to localizing an odour source are still unknown. We evaluated the ability of the silkmoth to localize an odour source under conditions of disturbed sensory-motor coupling, using a silkmoth-driven mobile robot. The significance of the bilateral olfaction of the moth was confirmed by inverting the olfactory input to the antennae, or its motor output. Inversion of the motor output induced consecutive circling, which was inhibited by covering the visual field of the moth. This suggests that the corollary discharge from the motor command and the reafference of self-generated optic flow generate compensatory signals to guide the surge accurately. Additionally, after inverting the olfactory input, the robot successfully tracked the odour plume by using a combination of behaviours. These results indicate that accurate guidance of the reflexive surge by integrating bilateral olfactory and visual information with innate pre-programmed behaviours increases the flexibility to track an odour plume even under disturbed circumstances. © 2015. Published by The Company of Biologists Ltd.

  2. A coupled viscoelastic-viscoplastic finite strain model for the dynamic behaviour of particulate composites: numerical issues

    NASA Astrophysics Data System (ADS)

    Fanget, A.; Trumel, H.; Dragon, A.

    1998-07-01

    The dynamic behaviour of a propellant like material is modelized with viscoelastic-viscoplastic behaviour in the lagrangian finite strain frame work. Employment of logarithmic strain allows elastic-plastic decomposidon. The viscoelastic part is performed in differential form and is integrated by an explicit method. The plastic deformation is split into volumetric and distorsional parts which constitute two distinct state variables for compaction and yielding. This model has been implemented in a finite element 2D code. The algorithm of the implementation is presented and numerical and experimental results are shown.

  3. Disclosure behaviour and intentions among 111 couples following treatment with oocytes or sperm from identity-release donors: follow-up at offspring age 1-4 years.

    PubMed

    Isaksson, S; Sydsjö, G; Skoog Svanberg, A; Lampic, C

    2012-10-01

    Do heterosexual parents of young children following oocyte donation (OD) and sperm donation (SD) tell or intend to tell their offspring about the way he/she was conceived? Following successful treatment with oocytes or sperm from identity-release donors in Sweden, almost all heterosexual couples intend to tell their offspring about the way he/she was conceived and some start the information-sharing process very early. Although the Swedish legislation on identity-release gamete donors has been in effect since 1985, there is a discrepancy between the behaviour of donor-insemination parents and the legal intention that offspring be informed about their genetic origin. The present study contributes data on a relatively large sample of oocyte and sperm recipient couples' intended compliance with the Swedish legislation. DESIGN AND DATA COLLECTION METHOD: The present study constitutes a follow-up assessment of heterosexual couples who had given birth to a child following treatment with donated oocytes. Data collection was performed during 2007-2011; participants individually completed a questionnaire when the child was between 1 and 4 years of age. The present study is part of the Swedish Study on Gamete Donation, a prospective longitudinal cohort study including all fertility clinics performing gamete donation in Sweden. For children conceived via OD, 107 individuals (including 52 couples and 3 individuals) agreed to participate (73% response). For children conceived via SD, the response rate was 70% (n = 122 individuals, including 59 couples and 4 individuals). Mean age of participants was 34 years (SD 4.4) and they reported a high level of education. The majority of participants (78%) planned to tell the child about the donation, 16% had already started the information-sharing process and 6% planned not to tell their child about the donation or were undecided. Many were unsure about a suitable time to start the disclosure process and desired more information about

  4. Disclosure behaviour and intentions among 111 couples following treatment with oocytes or sperm from identity-release donors: follow-up at offspring age 1–4 years

    PubMed Central

    Isaksson, S.; Sydsjö, G.; Skoog Svanberg, A.; Lampic, C.

    2012-01-01

    STUDY QUESTION Do heterosexual parents of young children following oocyte donation (OD) and sperm donation (SD) tell or intend to tell their offspring about the way he/she was conceived? SUMMARY ANSWER Following successful treatment with oocytes or sperm from identity-release donors in Sweden, almost all heterosexual couples intend to tell their offspring about the way he/she was conceived and some start the information-sharing process very early. WHAT IS KNOWN AND WHAT THIS PAPER ADDS Although the Swedish legislation on identity-release gamete donors has been in effect since 1985, there is a discrepancy between the behaviour of donor-insemination parents and the legal intention that offspring be informed about their genetic origin. The present study contributes data on a relatively large sample of oocyte and sperm recipient couples' intended compliance with the Swedish legislation. DESIGN AND DATA COLLECTION METHOD The present study constitutes a follow-up assessment of heterosexual couples who had given birth to a child following treatment with donated oocytes. Data collection was performed during 2007–2011; participants individually completed a questionnaire when the child was between 1 and 4 years of age. PARTICIPANTS AND SETTING The present study is part of the Swedish Study on Gamete Donation, a prospective longitudinal cohort study including all fertility clinics performing gamete donation in Sweden. For children conceived via OD, 107 individuals (including 52 couples and 3 individuals) agreed to participate (73% response). For children conceived via SD, the response rate was 70% (n = 122 individuals, including 59 couples and 4 individuals). Mean age of participants was 34 years (SD 4.4) and they reported a high level of education. MAIN RESULTS The majority of participants (78%) planned to tell the child about the donation, 16% had already started the information-sharing process and 6% planned not to tell their child about the donation or were undecided

  5. Single-molecule magnet behaviour in a tetrathiafulvalene-based electroactive antiferromagnetically coupled dinuclear dysprosium(III) complex.

    PubMed

    Pointillart, Fabrice; Le Gal, Yann; Golhen, Stéphane; Cador, Olivier; Ouahab, Lahcène

    2011-09-05

    The reactions between the [Ln(tta)(3)]·2H(2)O precursors (tta(-)=2-thenoyltrifluoroacetonate anion) and the tetrathiafulvalene-3-pyridine-N-oxide ligands (L(1)) lead to dinuclear complexes of formula [{Ln(tta)(3)(L(1))}(2)]·xCH(2)Cl(2) (x=0.5 for Ln=Dy(III) (1) and x=0 for Ln=Gd(III) (2)). The crystal structure reveals that two {Ln(tta)(3)} moieties are bridged by two donors through the nitroxide groups. The Dy(III) centre adopts a distorted square antiprismatic oxygenated polyhedron structure. The antiferromagnetic nature of the exchange interaction between the two Dy(III) ions has been determined by two methods: 1) an empirical method using the [Dy(hfac)(3)(L(2))(2)] mononuclear complex as a model (3) (hfac(-)=1,1,1,5,5,5-hexafluoroacetylacetonate anion, L(2)=tetrathiafulvaleneamido-2-pyridine-N-oxide ligand), and 2) assuming an Ising model for the Dy(III) ion giving an exchange energy of -2.30 cm(-1), g=19.2 in the temperature range of 2-10 K. The antiferromagnetic interactions have been confirmed by a quantitative determination of J for the isotropic Gd(III) derivative (J=-0.031 cm(-1), g=2.003). Compound 1 displays a slow magnetisation relaxation without applied external magnetic fields. Alternating current susceptibility shows a thermally activated behaviour with pre-exponential factors of 5.48(4)×10(-7) s and an energy barrier of 87(1) K. The application of an external field of 1.6 kOe compensates the antiferromagnetic interactions and opens a new quantum tunnelling path. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Evaluating a multicomponent social behaviour change communication strategy to reduce intimate partner violence among married couples: study protocol for a cluster randomized trial in Nepal.

    PubMed

    Clark, Cari Jo; Spencer, Rachael A; Shrestha, Binita; Ferguson, Gemma; Oakes, J Michael; Gupta, Jhumka

    2017-01-13

    Intimate partner violence (IPV) is a significant public health issue that affects 1 in 3 women globally and a similarly large number of women in Nepal. Over the past decade, important policy and programmatic steps have been taken to address violence against women in Nepal. There remains a dearth of evidence on the effectiveness of primary violence prevention strategies. The Change Starts at Home study begins to fill this gap by utilizing a multi-component social behaviour change communication (SBCC) strategy involving a radio drama and community mobilization to shift attitudes, norms and behaviours that underpin IPV perpetration in Nepal. The study uses a concurrent mixed-methods design. The quantitative aspect of the evaluation is a pair-matched, repeated cross-sectional 2-armed, single-blinded cluster trial (RCT: N = 36 clusters, 1440 individuals), comparing a social behaviour change communication (SBCC) strategy to radio programming alone for its impact on physical and / or sexual IPV at the end of programming (12 months' post-baseline) and 6-months post the cessation of project activities (18-months post baseline). The qualitative aspects of the design include several longitudinal approaches to understand the impact of the intervention and to examine mechanisms of change including in-depth interviews with participants (N = 18 couples), and focus group discussions with community leaders (N = 3 groups), and family members of participants (N = 12 groups). Treatment effects will be estimated with generalized logistic mixed models specified to compare differences in primary outcome from baseline to 12-month follow-up, and baseline to 18-months follow-up in accordance with intention-to-treat principles. The study rigorously evaluates the effectiveness of a promising strategy to prevent IPV. The results of the trial will be immediately useful for governmental, nongovernmental, and donor funded programs targeting partner violence or social norms that

  7. Coupled simulation of soil energy and water content to compare dielectric behaviour with TDR measurements in frozen soil

    NASA Astrophysics Data System (ADS)

    Muerth, Markus; Schlenz, Florian; Loew, Alexander; Mauser, Wolfram

    2010-05-01

    In the field of soil moisture monitoring both, on-site time domain reflectometry (TDR) methods and microwave remote sensing, measure the actual soil water content via the dielectric behavior of the soil-water-air mixture. Basically, the dielectric behavior is not only influenced by soil water content, but also by temperature, soil ice content, soil texture and porosity. However, many TDR and microwave techniques relate soil water content directly to soil dielectric behavior, because they lack the ability to determine the other relevant soil properties directly. The advantage of the combination of modeling and monitoring techniques for soil moisture monitoring is the ability to understand and compare spatial and temporal patterns, especially if other land surface properties influence the retrieved soil moisture signal. In this case, the hydrological land surface model PROMET (Processes of Mass, Energy and Radiation Transfer) is combined with TDR probe measurements taken at multiple sites and multiple depths during the winter 2008/2009 in south-eastern Germany. The harsh conditions, especially during January and February 2009 led to low measured liquid water contents in the upper 20 cm of the investigated soils, although the total water content remained nearly constant over time. Additionally, soil temperature and meteorological drivers were measured at nearby agrometeorological stations. Because PROMET has shown to simulate moisture content of non-frozen soils well, compared to TDR probe and remote sensing data, we investigate its ability to simulate frozen soil water content, when enhanced with an energy balance driven soil temperature module. Furthermore, a semi-empirical dielectric mixing model is implemented to directly compare the simulated soil dielectric behavior with the available TDR probe time series. It is shown that the explicit computation of the soil surface energy balance coupled with a physically based soil temperature model is able to simulate the

  8. Evaluation of the relative efficacy of a couple cognitive-behaviour therapy (CBT) for Premenstrual Disorders (PMDs), in comparison to one-to-one CBT and a wait list control: A randomized controlled trial

    PubMed Central

    2017-01-01

    Design A randomised control trial (RCT) was conducted to examine the efficacy of couple-based cognitive behaviour therapy (CBT) for Premenstrual Disorders (PMDs), in comparison to one-to-one CBT and a wait-list control. Methods Triangulation of quantitative and qualitative outcome measures evaluated changes pre-post intervention. Eighty three women were randomly allocated across three conditions, with 63 completing post-intervention measures, a retention rate of 76%. Results Repeated measures analysis of variance found a significant time by group interaction identifying that women in the two CBT conditions reported lower total premenstrual symptoms, emotional reactivity/mood, and premenstrual distress, in comparison to the wait list control. Significantly higher active behavioural coping post-intervention was found in the couple condition than in the one-to-one and wait list control groups. Qualitative analysis provided insight into the subjective experience of PMDs and participation in the intervention study. Across groups, women reported increased awareness and understanding of premenstrual change post-intervention. A larger proportion of women in the CBT conditions reported reduction in intensity and frequency of negative premenstrual emotional reactivity, increased communication and help-seeking, increased understanding and acceptance of embodied change, and the development of coping skills, post-intervention. Increased partner understanding and improved relationship post-intervention was reported by a greater proportion of participants in the CBT conditions, most markedly in the couple condition. Conclusion These findings suggest that one-to-one and couple CBT interventions can significantly reduce women’s premenstrual symptomatology and distress, and improve premenstrual coping. Couple based CBT interventions may have a greater positive impact upon behavioural coping and perceptions of relationship context and support. This suggests that CBT should be

  9. A coupled theory for chemically active and deformable solids with mass diffusion and heat conduction

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolong; Zhong, Zheng

    2017-10-01

    To analyse the frequently encountered thermo-chemo-mechanical problems in chemically active material applications, we develop a thermodynamically-consistent continuum theory of coupled deformation, mass diffusion, heat conduction and chemical reaction. Basic balance equations of force, mass and energy are presented at first, and then fully coupled constitutive laws interpreting multi-field interactions and evolving equations governing irreversible fluxes are constructed according to the energy dissipation inequality and the chemical kinetics. To consider the essential distinction between mass diffusion and chemical reactions in affecting free energy and dissipations of a highly coupled system, we regard both the concentrations of diffusive species and the extent of reaction as independent state variables. This new formulation then distinguishes between the energy contribution from the diffusive species entering the solid and that from the subsequent chemical reactions occurring among these species and the host solid, which not only interact with stresses or strains in different manners and on different time scales, but also induce different variations of solid microstructures and material properties. Taking advantage of this new description, we further establish a specialized isothermal model to predict precisely the transient chemo-mechanical response of a swelling solid with a proposed volumetric constraint that accounts for material incompressibility. Coupled kinetics is incorporated to capture the volumetric swelling of the solid caused by imbibition of external species and the simultaneous dilation arised from chemical reactions between the diffusing species and the solid. The model is then exemplified with two numerical examples of transient swelling accompanied by chemical reaction. Various ratios of characteristic times of diffusion and chemical reaction are taken into account to shed light on the dependency on kinetic time scales of evolution patterns for

  10. Achieving synchronization with active hybrid materials: Coupling self-oscillating gels and piezoelectric films

    NASA Astrophysics Data System (ADS)

    Yashin, Victor V.; Levitan, Steven P.; Balazs, Anna C.

    Our goal is to develop materials that compute by using non-linear oscillating chemical reactions to perform spatio-temporal recognition tasks. The material of choice is a polymer gel undergoing the oscillatory Belousov-Zhabotinsky reaction. The novelty of our approach is in employing hybrid gel-piezoelectric micro-electro-mechanical systems (MEMS) to couple local chemo-mechanical oscillations over long distances by electrical connection. Our modeling revealed that (1) interaction between the MEMS units is sufficiently strong for synchronization; (2) the mode of synchronization depends on the number of units, type of circuit connection (serial of parallel), and polarity of the units; (3) each mode has a distinctive pattern in phase of oscillations and generated voltage. The results indicate feasibility of using the hybrid gel-piezoelectric MEMS for oscillator based unconventional computing.

  11. Laser Shock Processing of Metallic Materials: Coupling of Laser-Plasma Interaction and Material Behaviour Models for the Assessment of Key Process Issues

    SciTech Connect

    Ocana, J. L.; Morales, M.; Molpeceres, C.; Porro, J. A.

    2010-10-08

    Profiting by the increasing availability of laser sources delivering intensities above 109 W/cm{sup 2} with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals. The main advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Although significant work from the experimental side has been contributed to explore the optimum conditions of application of the treatments and to assess their ultimate capability to provide enhanced mechanical behaviour to work-pieces of typical materials, only limited attempts have been developed in the way of full comprehension and predictive assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, a review on the physical issues dominating the development of LSP processes from a high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their predictive assessment and practical results at laboratory scale on the application of the technique to different materials.

  12. Laser Shock Processing of Metallic Materials: Coupling of Laser-Plasma Interaction and Material Behaviour Models for the Assessment of Key Process Issues

    NASA Astrophysics Data System (ADS)

    Ocaña, J. L.; Morales, M.; Molpeceres, C.; Porro, J. A.

    2010-10-01

    Profiting by the increasing availability of laser sources delivering intensities above 109 W/cm2 with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals. The main advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Although significant work from the experimental side has been contributed to explore the optimum conditions of application of the treatments and to assess their ultimate capability to provide enhanced mechanical behaviour to work-pieces of typical materials, only limited attempts have been developed in the way of full comprehension and predictive assessment of the characteristic physical processes and material transformations with a specific consideration of real material properties. In the present paper, a review on the physical issues dominating the development of LSP processes from a high intensity laser-matter interaction point of view is presented along with the theoretical and computational methods developed by the authors for their predictive assessment and practical results at laboratory scale on the application of the technique to different materials.

  13. A coupled mechanical and chemical damage model for concrete affected by alkali–silica reaction

    SciTech Connect

    Pignatelli, Rossella; Comi, Claudia; Monteiro, Paulo J.M.

    2013-11-15

    To model the complex degradation phenomena occurring in concrete affected by alkali–silica reaction (ASR), we formulate a poro-mechanical model with two isotropic internal variables: the chemical and the mechanical damage. The chemical damage, related to the evolution of the reaction, is caused by the pressure generated by the expanding ASR gel on the solid concrete skeleton. The mechanical damage describes the strength and stiffness degradation induced by the external loads. As suggested by experimental results, degradation due to ASR is considered to be localized around reactive sites. The effect of the degree of saturation and of the temperature on the reaction development is also modeled. The chemical damage evolution is calibrated using the value of the gel pressure estimated by applying the electrical diffuse double-layer theory to experimental values of the surface charge density in ASR gel specimens reported in the literature. The chemo-damage model is first validated by simulating expansion tests on reactive specimens and beams; the coupled chemo-mechanical damage model is then employed to simulate compression and flexure tests results also taken from the literature. -- Highlights: •Concrete degradation due to ASR in variable environmental conditions is modeled. •Two isotropic internal variables – chemical and mechanical damage – are introduced. •The value of the swelling pressure is estimated by the diffuse double layer theory. •A simplified scheme is proposed to relate macro- and microscopic properties. •The chemo-mechanical damage model is validated by simulating tests in literature.

  14. Achieving synchronization with active hybrid materials: Coupling self-oscillating gels and piezoelectric films

    PubMed Central

    Yashin, Victor V.; Levitan, Steven P.; Balazs, Anna C.

    2015-01-01

    Lightweight, deformable materials that can sense and respond to human touch and motion can be the basis of future wearable computers, where the material itself will be capable of performing computations. To facilitate the creation of “materials that compute”, we draw from two emerging modalities for computation: chemical computing, which relies on reaction-diffusion mechanisms to perform operations, and oscillatory computing, which performs pattern recognition through synchronization of coupled oscillators. Chemical computing systems, however, suffer from the fact that the reacting species are coupled only locally; the coupling is limited by diffusion as the chemical waves propagate throughout the system. Additionally, oscillatory computing systems have not utilized a potentially wearable material. To address both these limitations, we develop the first model for coupling self-oscillating polymer gels to a piezoelectric (PZ) micro-electro-mechanical system (MEMS). The resulting transduction between chemo-mechanical and electrical energy creates signals that can be propagated quickly over long distances and thus, permits remote, non-diffusively coupled oscillators to communicate and synchronize. Moreover, the oscillators can be organized into arbitrary topologies because the electrical connections lift the limitations of diffusive coupling. Using our model, we predict the synchronization behavior that can be used for computational tasks, ultimately enabling “materials that compute”. PMID:26105979

  15. Rotor dynamic behaviour of a high-speed oil-free motor compressor with a rigid coupling supported on four radial magnetic bearings

    NASA Technical Reports Server (NTRS)

    Schmied, J.; Pradetto, J. C.

    1994-01-01

    The combination of a high-speed motor, dry gas seals, and magnetic bearings realized in this unit facilitates the elimination of oil. The motor is coupled with a quill shaft to the compressor. This yields higher natural frequencies of the rotor than with the use of a diaphragm coupling and helps to maintain a sufficient margin of the maximum speed to the frequency of the second compressor bending mode. However, the controller of each bearing then has to take the combined modes of both machines into account. The requirements for the controller to ensure stability and sufficient damping of all critical speeds are designed and compared with the implemented controller. The calculated closed loop behavior was confirmed experimentally, except the stability of some higher modes due to slight frequency deviations of the rotor model to the actual rotor. The influence of a mechanical damper as a device to provide additional damping to high models is demonstrated theoretically. After all, it was not necessary to install the damper, since all modes cold be stabilized by the controller.

  16. Modelling real disease dynamics with behaviourally adaptive complex networks. Comment on "Coupled disease-behavior dynamics on complex networks: A review" by Z. Wang et al.

    NASA Astrophysics Data System (ADS)

    Small, Michael

    2015-12-01

    Mean field compartmental models of disease transmission have been successfully applied to a host of different scenarios, and the Kermack-McKendrick equations are now a staple of mathematical biology text books. In Susceptible-Infected-Removed format these equations provide three coupled first order ordinary differential equations with a very mild nonlinearity and they are very well understood. However, underpinning these equations are two important assumptions: that the population is (a) homogeneous, and (b) well-mixed. These assumptions become closest to being true for diseases infecting a large portion of the population for which inevitable individual effects can be averaged away. Emerging infectious disease (such as, in recent times, SARS, avian influenza, swine flu and ebola) typically does not conform to this scenario. Individual contacts and peculiarities of the transmission network play a vital role in understanding the dynamics of such relatively rare infections - particularly during the early stages of an outbreak.

  17. Qualitative and quantitative characterization of the arsenic-binding behaviour of sulfur-containing peptides and proteins by the coupling of reversed phase liquid chromatography to electrospray ionization mass spectrometry.

    PubMed

    Schmidt, Anne-Christine; Mickein, Kathleen

    2012-08-01

    Phenylarsenic-substituted cysteine-containing peptides and proteins were completely differentiated from their unbound original forms by the coupling of reversed phase liquid chromatography with electrospray ionization mass spectrometry. The analysis of biomolecules possessing structure-stabilizing disulfide bridges after reduction provides new insights into requirements concerning the accessibility of cysteine residues for reducing agents as well as for arsenic compounds in a spatial protein structure. Complementary binding studies performed using direct ESI-MS without chromatographic coupling in different solvent systems demonstrated that more than one binding site were activated for aprotinin and lysozyme in denaturing solvents because of a stronger defolding. From the intensities of the different charge states occurring in the mass spectra as well as from the LC elution behaviour, it can be deduced that the folding state of the arsenic-bound protein species resembles the native, oxidized conformation. In contrast, although the milk protein α-lactalbumin has several disulfide bridges, only one phenylarsenic moiety was bound under strongly denaturing conditions. Because of the charge state distribution in the ESI mass spectra, a conformational change to a molten globule structure is assumed. For the second considered milk protein ß-lactoglobulin, a noncovalent interaction with phenylarsine oxide was detected. In general, smaller apparent binding constants for the condensation reactions of the biomolecules with phenylarsine oxide leading to covalent arsenic-sulfur bindings were determined from direct injection ESI-MS measurements than from LC-ESI-MS coupling. The following order of binding affinities for one phenylarsenic group can be assumed from both ESI-MS and LC-ESI-MS: nonapeptide vasopressin > nonapeptide vasotocin > lysozyme > aprotinin > α-lactalbumin > thioredoxin. Kinetic investigations by LC-ESI-MS yielded a partial reaction order

  18. Multiple-Code BenchMaek Simulation Stidy of Coupled THMC Processes IN the EXCAVATION DISTURBED ZONE Associated with Geological Nuclear Waste Repositories

    SciTech Connect

    J. Rutqvist; X. Feng; J. Hudson; L. Jing; A. Kobayashi; T. Koyama; P.Pan; H. Lee; M. Rinne; E. Sonnenthal; Y. Yamamoto

    2006-05-08

    An international, multiple-code benchmark test (BMT) study is being conducted within the international DECOVALEX project to analyze coupled thermal, hydrological, mechanical and chemical (THMC) processes in the excavation disturbed zone (EDZ) around emplacement drifts of a nuclear waste repository. This BMT focuses on mechanical responses and long-term chemo-mechanical effects that may lead to changes in mechanical and hydrological properties in the EDZ. This includes time-dependent processes such as creep, and subcritical crack, or healing of fractures that might cause ''weakening'' or ''hardening'' of the rock over the long term. Five research teams are studying this BMT using a wide range of model approaches, including boundary element, finite element, and finite difference, particle mechanics, and elasto-plastic cellular automata methods. This paper describes the definition of the problem and preliminary simulation results for the initial model inception part, in which time dependent effects are not yet included.

  19. A time-sequence functional analysis of mating behaviour and genital coupling in Drosophila: role of cryptic female choice and male sex-drive in the evolution of male genitalia.

    PubMed

    Jagadeeshan, S; Singh, R S

    2006-07-01

    Male genitalia in Drosophila exemplify strikingly rapid and divergent evolution, whereas female genitalia are relatively invariable. Whereas precopulatory and post-copulatory sexual selection has been invoked to explain this trend, the functional significance of genital structures during copulation remains obscure. We used time-sequence analysis to study the functional significance of external genitalic structures during the course of copulation, between D. melanogaster and D. simulans. This functional analysis has provided new information that reveals the importance of male-driven copulatory mechanics and strategies in the rapid diversification of genitalia. The posterior process, which is a recently evolved sexual character and present only in males of the melanogaster clade, plays a crucial role in mounting as well as in genital coupling. Whereas there is ample evidence for precopulatory and/or post-copulatory female choice, we show here that during copulation there is little or no physical female choice, consequently, males determine copulation duration. We also found subtle differences in copulatory mechanics between very closely related species. We propose that variation in male usage of novel genitalic structures and shifts in copulatory behaviour have played an important role in the diversification of genitalia in species of the Drosophila subgroup.

  20. Predictors of health behaviours in college students.

    PubMed

    Von Ah, Diane; Ebert, Sheryl; Ngamvitroj, Anchalee; Park, Najin; Kang, Duck-Hee

    2004-12-01

    This paper reports a study examining the direct effects of perceived stress, perceived availability of and satisfaction with social support, and self-efficacy, and examines the intermediary roles of perceived threat (perceived susceptibility x perceived severity), benefits, and barriers on alcohol behaviour, smoking behaviour, physical activity and nutrition behaviour, general safety behaviour and sun-protective behaviour in college students. Health behaviours formed during young adulthood may have a sustaining impact on health across later life. Entering college can be an exciting, yet stressful event for many adolescents and young adults as they face trying to adapt to changes in academic workloads, support networks, and their new environment. Coupled with these changes and new-found responsibilities, they have greater freedom and control over their lifestyles than ever before. However, researchers have shown globally that many college students engage in various risky health behaviours. A cross-sectional sample of 161 college students enrolled in an introductory psychology course completed self-report questionnaires regarding stress; social support; self-efficacy; and components of the Health Belief Model including perceived threat, perceived benefits, perceived barriers; and common health behaviours. Step-wise multiple regression analysis was conducted and significant predictors were retained as modifiers in the path analysis. Self-efficacy significantly predicted alcohol and smoking behaviour, physical activity and nutrition protective behaviour, general safety protective behaviour and sun-protective behaviour. Under high-perceived threat, self-efficacy was mediated by perceived barriers for binge drinking and moderated by perceived barriers for physical activity and nutrition behaviours. In addition, under high-perceived threat, self-efficacy was moderated by perceived threat for alcohol use at 30 days and 6 months. Under low threat, self-efficacy was mediated

  1. Capturing poromechanical coupling effects of the reactive fracturing process in porous rock via a DEM-network model

    NASA Astrophysics Data System (ADS)

    Ulven, Ole Ivar; Sun, WaiChing

    2016-04-01

    Fluid transport in a porous medium has important implications for understanding natural geological processes. At a sufficiently large scale, a fluid-saturated porous medium can be regarded as a two-phase continuum, with the fluid constituent flowing in the Darcian regime. Nevertheless, a fluid mediated chemical reaction can in some cases change the permeability of the rock locally: Mineral dissolution can cause increased permeability, whereas mineral precipitation can reduce the permeability. This might trigger a complicated hydro-chemo-mechanical coupling effect that causes channeling of fluids or clogging of the system. If the fluid is injected or produced at a sufficiently high rate, the pressure might increase enough to cause the onset and propagation of fractures. Fractures in return create preferential flow paths that enhance permeability, localize fluid flow and chemical reaction, prevent build-up of pore pressure and cause anisotropy of the hydro-mechanical responses of the effective medium. This leads to a complex coupled process of solid deformation, chemical reaction and fluid transport enhanced by the fracture formation. In this work, we develop a new coupled numerical model to study the complexities of feedback among fluid pressure evolution, fracture formation and permeability changes due to a chemical process in a 2D system. We combine a discrete element model (DEM) previously used to study a volume expanding process[1, 2] with a new fluid transport model based on poroelasticity[3] and a fluid-mediated chemical reaction that changes the permeability of the medium. This provides new insights into the hydro-chemo-mechanical process of a transforming porous medium. References [1] Ulven, O. I., Storheim, H., Austrheim, H., and Malthe-Sørenssen, A. "Fracture Initiation During Volume Increasing Reactions in Rocks and Applications for CO2 Sequestration", Earth Planet. Sc. Lett. 389C, 2014a, pp. 132 - 142, doi:10.1016/j.epsl.2013.12.039. [2] Ulven, O. I

  2. A staggered approach for the coupling of Cahn-Hilliard type diffusion and finite strain elasticity

    NASA Astrophysics Data System (ADS)

    Areias, P.; Samaniego, E.; Rabczuk, T.

    2016-02-01

    We develop an algorithm and computational implementation for simulation of problems that combine Cahn-Hilliard type diffusion with finite strain elasticity. We have in mind applications such as the electro-chemo-mechanics of lithium ion (Li-ion) batteries. We concentrate on basic computational aspects. A staggered algorithm is proposed for the coupled multi-field model. For the diffusion problem, the fourth order differential equation is replaced by a system of second order equations to deal with the issue of the regularity required for the approximation spaces. Low order finite elements are used for discretization in space of the involved fields (displacement, concentration, nonlocal concentration). Three (both 2D and 3D) extensively worked numerical examples show the capabilities of our approach for the representation of (i) phase separation, (ii) the effect of concentration in deformation and stress, (iii) the effect of strain in concentration, and (iv) lithiation. We analyze convergence with respect to spatial and time discretization and found that very good results are achievable using both a staggered scheme and approximated strain interpolation.

  3. Pulse-coupled BZ oscillators with unequal coupling strengths.

    PubMed

    Horvath, Viktor; Kutner, Daniel J; Chavis, John T; Epstein, Irving R

    2015-02-14

    Coupled chemical oscillators are usually studied with symmetric coupling, either between identical oscillators or between oscillators whose frequencies differ. Asymmetric connectivity is important in neuroscience, where synaptic strength inequality in neural networks commonly occurs. While the properties of the individual oscillators in some coupled chemical systems may be readily changed, enforcing inequality between the connection strengths in a reciprocal coupling is more challenging. We recently demonstrated a novel way of coupling chemical oscillators, which allows for manipulation of individual connection strengths. Here we study two identical, pulse-coupled Belousov-Zhabotinsky (BZ) oscillators with unequal connection strengths. When the pulse perturbations contain KBr (inhibitor), this system exhibits simple out-of-phase and complex oscillations, oscillatory-suppressed states as well as temporally periodic patterns (N : M) in which the two oscillators exhibit different numbers of peaks per cycle. The N : M patterns emerge due to the long-term effect of the inhibitory pulse-perturbations, a feature that has not been considered in earlier works. Time delay was previously shown to have a profound effect on the system's behaviour when pulse coupling was inhibitory and the coupling strengths were equal. When the coupling is asymmetric, however, delay produces no qualitative change in behaviour, though the 1 : 2 temporal pattern becomes more robust. Asymmetry in instantaneous excitatory coupling via AgNO3 injection produces a previously unseen temporal pattern (1 : N patterns starting with a double peak) with time delay and high [AgNO3]. Numerical simulations of the behaviour agree well with theoretical predictions in asymmetrical pulse-coupled systems.

  4. Geo-Chemo-Mechanical Studies for Permanent CO{sub 2} Storage in Geologic Reservoirs

    SciTech Connect

    Kelemen, Peter; Park, Ah-hyung; Matter, Jurg; Gadikota, Greeshma; Lisabeth, Harrison; Zhu, Wenlu

    2013-09-30

    This two-pronged study investigated the rates and mechanisms of formation of Ca and Mg carbonate minerals via reaction of aqueous fluids with silicate minerals and rocks, and the geomechanical effects of such reactions. The kinetic studies focused on the separation of variables, following from previous studies demonstrating rapid formation of carbonates via reaction of the mineral olivine with aqueous fluids rich in NaHCO{sub 3} (plus KHCO{sub 3} and RbHCO{sub 3}) and NaCl at a high partial pressure of CO{sub 2}. We wished to separate and quantify the effects of NaHCO{sub 3} and NaCl, and to investigate whether bicarbonate-rich, aqueous fluids would also cause rapid formation of carbonates via reaction with other minerals and rocks. Further, we wished to improve upon previous work by adding precise characterization of grain size distributions and surface area, and their changes as a result of reaction. We confirmed previous reports of very rapid olivine carbonation. We found that at a given temperature and CO{sub 2} partial pressure the previously observed rate enhancement in olivine carbonation is due mainly to NaHCO{sub 3}, and not to dissolved NaCl. Further, though reaction of the mineral plagioclase, and two rock compositions, were all faster in the presence of NaHCO{sub 3}-rich fluids, compared with saline and de-ionized water, they were all much slower than reaction of olivine. In the experiments showing the fastest reaction rate, average grain size tended to increase during experiments, presumably due to dissolution of small reactant grains plus growth of product phases on reactant surfaces. Porosity/surface area of grains tended to change with reaction progress, due to the formation of dissolution pits and irregular growth of product phases on reactant grain surfaces. Development of a passivating phase (e.g., a layer of silica) due to incongruent dissolution of solid reactants and/or precipitation of solid products was detected, but was relatively minor and did not have a discernable effect on reaction progress. Geomechanical experiments did not identify pressure-temperature-composition conditions under which porous olivine aggregates undergo reaction driven cracking. Little carbonate formed in these experiments. Though we fulfilled the milestones for this project, a variety of reasons for this remain to be investigated in the future. Reaction of porous olivine aggregates with brines rich in NaHCO{sub 3} caused substantial weakening of samples in compression, due to formation of dissolution pits along olivine-olivine grain boundaries, reducing the solid-solid surface area. A preliminary modeling study funded in part by this grant emphasized potential rate enhancements due to reaction-driven cracking. In related research, not funded by this grant, several additional experimental and modeling studies of reaction-driven cracking are underway.

  5. The condensed chromatin fiber: an allosteric chemo-mechanical machine for signal transduction and genome processing

    NASA Astrophysics Data System (ADS)

    Lesne, Annick; Bécavin, Christophe; Victor, Jean–Marc

    2012-02-01

    Allostery is a key concept of molecular biology which refers to the control of an enzyme activity by an effector molecule binding the enzyme at another site rather than the active site (allos = other in Greek). We revisit here allostery in the context of chromatin and argue that allosteric principles underlie and explain the functional architecture required for spacetime coordination of gene expression at all scales from DNA to the whole chromosome. We further suggest that this functional architecture is provided by the chromatin fiber itself. The structural, mechanical and topological features of the chromatin fiber endow chromosomes with a tunable signal transduction from specific (or nonspecific) effectors to specific (or nonspecific) active sites. Mechanical constraints can travel along the fiber all the better since the fiber is more compact and regular, which speaks in favor of the actual existence of the (so-called 30 nm) chromatin fiber. Chromatin fiber allostery reconciles both the physical and biochemical approaches of chromatin. We illustrate this view with two supporting specific examples. Moreover, from a methodological point of view, we suggest that the notion of chromatin fiber allostery is particularly relevant for systemic approaches. Finally we discuss the evolutionary power of allostery in the context of chromatin and its relation to modularity.

  6. Effect of chemo-mechanical disintegration on sludge anaerobic digestion for enhanced biogas production.

    PubMed

    Kavitha, S; Pray, S Saji; Yogalakshmi, K N; Kumar, S Adish; Yeom, Ick-Tae; Banu, J Rajesh

    2016-02-01

    The effect of combined surfactant-dispersion pretreatment on dairy waste activated sludge (WAS) reduction in anaerobic digesters was investigated. The experiments were performed with surfactant, Sodium dodecyl sulfate (SDS) in the range of 0.01 to 0.1 g/g suspended solids (SS) and disperser with rpm of 5000-25,000. The COD (chemical oxygen demand) solubilization, suspended solids reduction, and biogas generation increased for an energy input of 7377 kJ/kg total solids (TS) (12,000 rpm, 0.04 g/g SS, and 30 min) and were found to be 38, 32, and 75 %, higher than that of control. The pretreated sludge improved the performance of semicontinuous anaerobic digesters of 4 L working volume operated at four different SRTs (sludge retention time). SRT of 15 days was found to be appropriate showing 49 and 51 % reduction in SS and volatile solids (VS), respectively. The methane yield of the pretreated sample was observed to be 50 mL/g VS removed which was observed to be comparatively higher than the control (12 mL/g VS removed) at optimal SRT of 15 days. To the best of the authors' knowledge, this study is the first to be reported and not yet been documented in literature.

  7. Shrink Wrapping Cells in a Defined Extracellular Matrix to Modulate the Chemo-Mechanical Microenvironment.

    PubMed

    Palchesko, Rachelle N; Szymanski, John M; Sahu, Amrita; Feinberg, Adam W

    2014-09-01

    Cell-matrix interactions are important for the physical integration of cells into tissues and the function of insoluble, mechanosensitive signaling networks. Studying these interactions in vitro can be difficult because the extracellular matrix (ECM) proteins that adsorb to in vitro cell culture surfaces do not fully recapitulate the ECM-dense basement membranes to which cells such as cardiomyocytes and endothelial cells adhere to in vivo. Towards addressing this limitation, we have developed a surface-initiated assembly process to engineer ECM proteins into nanostructured, microscale sheets that can be shrink wrapped around single cells and small cell ensembles to provide a functional and instructive matrix niche. Unlike current cell encapsulation technology using alginate, fibrin or other hydrogels, our engineered ECM is similar in density and thickness to native basal lamina and can be tailored in structure and composition using the proteins fibronectin, laminin, fibrinogen, and/or collagen type IV. A range of cells including C2C12 myoblasts, bovine corneal endothelial cells and cardiomyocytes survive the shrink wrapping process with high viability. Further, we demonstrate that, compared to non-encapsulated controls, the engineered ECM modulates cytoskeletal structure, stability of cell-matrix adhesions and cell behavior in 2D and 3D microenvironments.

  8. Chemo-mechanical modeling for prediction of alkali silica reaction (ASR) expansion

    SciTech Connect

    Multon, Stephane Sellier, Alain; Cyr, Martin

    2009-06-15

    The effect of the size of the aggregate on ASR expansion has already been well illustrated. This paper presents a microscopic model to analyze the development of ASR expansion of mortars containing reactive aggregate of different sizes. The attack of the reactive silica by alkali was determined through the mass balance equation, which controls the diffusion mechanism in the aggregate and the fixation of the alkali in the ASR gels. The mechanical part of the model is based on the damage theory in order to assess the decrease of stiffness of the mortar due to cracking caused by ASR and to calculate the expansion of a Representative Elementary Volume (REV) of concrete. Parameters of the model were estimated by curve fitting the expansions of four experimental mortars. The paper shows that the decrease of expansion with the size of the aggregate and the increase of the expansion with the alkali content are reproduced by the model, which is able to predict the expansions of six other mortars containing two sizes of reactive aggregate and cast with two alkali contents.

  9. Laboratory electrical studies on the thermo-chemo-mechanics of faults and fault slip

    NASA Astrophysics Data System (ADS)

    Eccles, David

    In nature, electrical signals have been recorded contemporaneously with volcanic and seismic activity, and have been proposed as precursors to earthquakes and volcanic eruptions. In the hydrocarbon industry, streaming potentials are used to investigate steam fronts, thus aiding enhanced oil recovery. There is therefore considerable current interest in electrical signals emanating from the Earth's crust and the mechanisms which give rise to them. Two of the theories that have been proposed to explain electrical signal generation are: The piezoelectric effect, caused by stress changes on piezoelectric minerals, such as quartz, which is found in many crustal rocks. The electrokinetic phenomenon, produced at a solid-liquid interface, where an electrokinetic current such as the streaming potential can be induced through a pressure, chemical or temperature gradient, resulting in electrical charge transport within the moving fluid. In order to investigate the possible mechanisms responsible for the generation of electrical signals in the Earth's crust, carefully controlled laboratory rock deformation and rock physics experiments have been performed under simulated shallow crustal conditions, where both electrical potential signals and acoustic emissions were measured. The deformation strain rate, confining pressure, pore fluid pressure, pore fluid chemistry and temperature were all varied systematically during conventional triaxial rock deformation tests on a range of rock types. Confining pressures were varied from 20 MPa to 100 MPa, pore fluid pressures from 5 MPa to 40 MPa, strain rates from 1.5 x 10"4 s"1 to 1.5 x 10"7 s"1 and temperatures from room temperature (25 C) up to 125 C. Over thirty five experiments were completed at room temperature on rock samples Clashach, Bentheim and Darley Dale sandstones and Portland limestone. More than ten experiments were done at elevated temperature on both dry and saturated samples of Clashach sandstone using a range of pore fluid chemistries. Significant developments in experimental apparatus were necessary for these latter experiments, including the design and construction of an electrical internal heater for the triaxial deformation cell. I identify that, for the temperature range between 25 and 125 C, that the primary sources of electrical potential signal generation are (i) piezoelectric in dry quartz-rich sandstone and (ii) electrokinetic in saturated samples of both sandstones and limestone. Factors that are found to influence the electrical potential signals during deformation include effective pressure, temperature, strain rate, pore fluid type and fluid flow. As failure is approached, both pre-seismic and co-seismic signals are observed with the magnitude of the signals varying with rock type. These observations can be explained by differences in the rock composition and variation in hydraulic and electrical pathways available for electric current flow during rock deformation. Variation in electrical potential difference can be seen during both the compactive and dilatant stages of deformation. At slower strain rates, local rock variation can be seen through changes in electrical potential signals which appear to be obscured at higher strain rates. The change in electrical and streaming potential signals during deformation reflect both the accumulating and accelerating damage identified by acoustic emission prior to fracture and the localisation of damage at dynamic fracture. After failure the potential decreases to a background value where it remains during constant frictional sliding at essentially constant stress. The presence of a crack or fault was identified to affect the electrical and streaming potential signals depending on their relative position with respect to the fault suggesting that electrical potential could be used as a method for fault location. An increase in temperature was found not to affect the mechanical properties within the range of experimental conditions explored. The effect of increased temperature on the electrical potential s

  10. pH-responsive hydrogel coated fiber Bragg grating-based chemo mechanical sensor bioreactor applications

    NASA Astrophysics Data System (ADS)

    Kishore, P. V. N.; Sai Shankar, M.

    2017-04-01

    This paper describes a fiber optics based pH sensor by using wavelength modulated techniques. Fiber Bragg grating (FBG) is functionalized with a stimulus responsive hydrogel which induces a strain on FBG due to mechanical expansion of the gel in response to ambient pH changes. The gel is synthesized from the blends of Poly (vinyl alcohol)/Poly (acrylic acid). The induced strain results in a shift of FBG reflected peak which is monitored by an interrogator. The sensor system shows a good linearity in acidic pH range of 3 to 7 with a sensitivity of 12.16pm/pH. Besides that it shows good repeatability which proves it to be fit for pH sensing applications.

  11. Coupled Mechanical and Electrochemical Phenomena in Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Cannarella, John

    Lithium-ion batteries are complee electro-chemo-mechanical systems owing to a number of coupled mechanical and electrochemical phenomena that occur during operation. In this thesis we explore these phenomena in the context of battery degradation, monitoring/diagnostics, and their application to novel energy systems. We begin by establishing the importance of bulk stress in lithium-ion batteries through the presentation of a two-year exploratory aging study which shows that bulk mechanical stress can significantly accelerate capacity fade. We then investigate the origins of this coupling between stress and performance by investigating the effects of stress in idealized systems. Mechanical stress is found to increase internal battery resistance through separator deformation, which we model by considering how deformation affects certain transport properties. When this deformation occurs in a spatially heterogeneous manner, local hot spots form, which accelerate aging and in some cases lead to local lithium plating. Because of the importance of separator deformation with respect to mechanically-coupled aging, we characterize the mechanical properties of battery separators in detail. We also demonstrate that the stress state of a lithium-ion battery cell can be used to measure the cell's state of health (SOH) and state of charge (SOC)--important operating parameters that are traditionally difficult to measure outside of a laboratory setting. The SOH is shown to be related to irreversible expansion that occurs with degradation and the SOC to the reversible strains characteristic of the cell's electrode materials. The expansion characteristics and mechanical properties of the constituent cell materials are characterized, and a phenomenological model for the relationship between stress and SOH/SOC is developed. This work forms the basis for the development of on-board monitoring of SOH/SOC based on mechanical measurements. Finally we study the coupling between mechanical

  12. Unintentional behaviour change.

    PubMed

    Aunger, Robert; Curtis, Valerie

    2014-08-01

    We argue that the authors ignore a broad range of possible means of changing behaviour: unintentional change. Most of the behaviours that people seek to change - either in themselves or that are the subject of public health campaigns-are habitual, and hence not necessarily responsive to intentions. An evolutionary approach should take into account all kinds of evolved behavioural responses.

  13. Imitation as behaviour parsing.

    PubMed Central

    Byrne, R W

    2003-01-01

    Non-human great apes appear to be able to acquire elaborate skills partly by imitation, raising the possibility of the transfer of skill by imitation in animals that have only rudimentary mentalizing capacities: in contrast to the frequent assumption that imitation depends on prior understanding of others' intentions. Attempts to understand the apes' behaviour have led to the development of a purely mechanistic model of imitation, the 'behaviour parsing' model, in which the statistical regularities that are inevitable in planned behaviour are used to decipher the organization of another agent's behaviour, and thence to imitate parts of it. Behaviour can thereby be understood statistically in terms of its correlations (circumstances of use, effects on the environment) without understanding of intentions or the everyday physics of cause-and-effect. Thus, imitation of complex, novel behaviour may not require mentalizing, but conversely behaviour parsing may be a necessary preliminary to attributing intention and cause. PMID:12689378

  14. Motivational wheel running reverses cueing behavioural inflexibility in rodents.

    PubMed

    Chomiak, Taylor; Brown, Andrew R; Teskey, G Campbell; Hu, Bin

    2017-09-18

    Behavioural inflexibility and associated atypical learning behaviours are common clinical manifestations of the autism spectrum disorder (ASD) phenotype. Despite advances in our understanding of ASD, little research has been devoted to experimental interventions that might help to circumvent behavioural inflexibility in ASD. The current paper suggests that motivational locomotion in the form of wheel running can reduce behavioural inflexibility and learning impairments in an ASD rat model, and discusses how the strategy of reward-coupled locomotor activity may lead to clinical interventions for children with ASD.

  15. Behavioural fever in zebrafish larvae.

    PubMed

    Rey, Sonia; Moiche, Visila; Boltaña, Sebastian; Teles, Mariana; MacKenzie, Simon

    2017-02-01

    Behavioural fever has been reported in different species of mobile ectotherms including the zebrafish, Danio rerio, in response to exogenous pyrogens. In this study we report, to our knowledge for the first time, upon the ontogenic onset of behavioural fever in zebrafish (Danio rerio) larvae. For this, zebrafish larvae (from first feeding to juveniles) were placed in a continuous thermal gradient providing the opportunity to select their preferred temperature. The novel thermal preference aquarium was based upon a continuous vertical column system and allows for non-invasive observation of larvae vertical distribution under isothermal (TR at 28 °C) and thermal gradient conditions (TCH: 28-32 °C). Larval thermal preference was assessed under both conditions with or without an immersion challenge, in order to detect the onset of the behavioural fever response. Our results defined the onset of the dsRNA induced behavioural fever at 18-20 days post fertilization (dpf). Significant differences were observed in dsRNA challenged larvae, which prefer higher temperatures (1-4 °C increase) throughout the experimental period as compared to non-challenged larvae. In parallel we measured the abundance of antiviral transcripts; viperin, gig2, irf7, trim25 and Mxb mRNAs in dsRNA challenged larvae under both thermal regimes: TR and TCh. Significant increases in the abundance of all measured transcripts were recorded under thermal choice conditions signifying that thermo-coupling and the resultant enhancement of the immune response to dsRNA challenge occurs from 18 dpf onwards in the zebrafish. The results are of importance as they identify a key developmental stage where the neuro-immune interface matures in the zebrafish likely providing increased resistance to viral infection.

  16. Helix coupling

    DOEpatents

    Ginell, W.S.

    1982-03-17

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the U sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  17. Helix coupling

    DOEpatents

    Ginell, W.S.

    1989-04-25

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  18. Helix coupling

    DOEpatents

    Ginell, William S.

    1989-04-25

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  19. Kinetic coupling of phosphate release, force generation and rate-limiting steps in the cross-bridge cycle.

    PubMed

    Stehle, Robert; Tesi, Chiara

    2017-09-16

    A basic goal in muscle research is to understand how the cyclic ATPase activity of cross-bridges is converted into mechanical force. A direct approach to study the chemo-mechanical coupling between Pi release and the force-generating step is provided by the kinetics of force response induced by a rapid change in [Pi]. Classical studies on fibres using caged-Pi discovered that rapid increases in [Pi] induce fast force decays dependent on final [Pi] whose kinetics were interpreted to probe a fast force-generating step prior to Pi release. However, this hypothesis was called into question by studies on skeletal and cardiac myofibrils subjected to Pi jumps in both directions (increases and decreases in [Pi]) which revealed that rapid decreases in [Pi] trigger force rises with slow kinetics, similar to those of calcium-induced force development and mechanically-induced force redevelopment at the same [Pi]. A possible explanation for this discrepancy came from imaging of individual sarcomeres in cardiac myofibrils, showing that the fast force decay upon increase in [Pi] results from so-called sarcomere 'give'. The slow force rise upon decrease in [Pi] was found to better reflect overall sarcomeres cross-bridge kinetics and its [Pi] dependence, suggesting that the force generation coupled to Pi release cannot be separated from the rate-limiting transition. The reasons for the different conclusions achieved in fibre and myofibril studies are re-examined as the recent findings on cardiac myofibrils have fundamental consequences for the coupling between Pi release, rate-limiting steps and force generation. The implications from Pi-induced force kinetics of myofibrils are discussed in combination with historical and recent models of the cross-bridge cycle.

  20. Changes in the acoustic environment alter the foraging and sheltering behaviour of the cichlid Amititlania nigrofasciata.

    PubMed

    McLaughlin, Kirsty Elizabeth; Kunc, Hansjoerg P

    2015-07-01

    Anthropogenic noise can affect behaviour across a wide range of species in both terrestrial and aquatic environments. However, behaviours might not be affected in isolation. Therefore, a more holistic approach investigating how environmental stressors, such as noise pollution, affect different behaviours in concert is necessary. Using tank-based noise exposure experiments, we tested how changes in the acoustic environment affect the behaviour of the cichlid Amatitlania nigrofasciata. We found that exposure to anthropogenic noise affected a couple of behaviours: an increase in sheltering was accompanied by a decrease in foraging. Our results highlight the multiple negative effects of an environmental stressor on an individual's behaviour.

  1. Neurobiology of suicidal behaviour.

    PubMed

    Pjevac, Milica; Pregelj, Peter

    2012-10-01

    It is known that suicidal behaviour has multiple causes. If triggers could be mainly attributed to environmental factors, predisposition could be associated with early stressors on one side such as childhood adversities and genetic predisposition. No convincing animal model of suicide has been produced to date. The study of endophenotypes has been proposed as a good strategy to overcome the methodological difficulties. However, research in suicidal behaviours using endophenotypes entrails important methodological problems. Further, serotoninergic system was studied in patients with suicidal behaviour primary due to its involvement of serotonin in impulsive-aggressive behaviour, which has been shown to be a major risk factor in suicidal behaviour. Not only on the level of neurotransmitters but also the regulation of neurotropic factors could be impaired in suicide victims. Multiple lines of evidence including studies of levels of BDNF in blood cells and plasma of suicidal patients, postmortem brain studies in suicidal subjects with or without depression, and genetic association studies linking BDNF to suicide suggest that suicidal behaviour may be associated with a decrease in BDNF functioning. It seems that especially specific gene variants regulating the serotoninergic system and other neuronal systems involved in stress response are associated with suicidal behaviour. Most genetic studies on suicidal behaviour have considered a small set of functional polymorphisms relevant mostly to monoaminergic neurotransmission. However, genes and epigenetic mechanisms involved in regulation of other factors such as BDNF seem to be even more relevant for further research.

  2. Behavioural aspects of terrorism.

    PubMed

    Leistedt, Samuel J

    2013-05-10

    Behavioural and social sciences are useful in collecting and analysing intelligence data, understanding terrorism, and developing strategies to combat terrorism. This article aims to examine the psychopathological concepts of terrorism and discusses the developing roles for behavioural scientists. A systematic review was conducted of studies investigating behavioural aspects of terrorism. These studies were identified by a systematic search of databases, textbooks, and a supplementary manual search of references. Several fundamental concepts were identified that continue to influence the motives and the majority of the behaviours of those who support or engage in this kind of specific violence. Regardless of the psychological aspects and new roles for psychiatrists, the behavioural sciences will continue to be called upon to assist in developing better methods to gather and analyse intelligence, to understand terrorism, and perhaps to stem the radicalisation process.

  3. Behavioural determinants of obesity.

    PubMed

    Rennie, Kirsten L; Johnson, Laura; Jebb, Susan A

    2005-09-01

    Obesity in children arises from a complex interplay between genetic susceptibility and behaviour, primarily relating to dietary habits and physical activity. Evidence for specific behavioural factors that promote or protect against excess weight gain in children is more limited than in adults, and the effects of growth and development are not clear. A number of behavioural risk factors has been postulated, including diets with a high energy density, high consumption of sugar-sweetened beverages, large portion sizes, eating patterns, high levels of sedentary behaviour and low levels of physical activity. However, most evidence is derived from cross-sectional studies which frequently yield conflicting results. More prospective studies with accurate measures of exposures and outcomes in terms of body composition are needed to provide more robust evidence on which to base interventions to achieve long-term behavioural change and prevent excess weight gains in children.

  4. Somnambulistic sexual behaviour (sexsomnia).

    PubMed

    Ebrahim, Irshaad Osman

    2006-05-01

    Somnambulism or sleepwalking is a viable defence on the basis of automatism. The behaviours that occur during sleepwalking can be highly complex and include sexual behaviour of all types. Somnambulistic sexual behaviour (also called sexsomnia, sleep sex) is considered a variant of sleepwalking disorder as the overwhelming majority of people with Sexsomnia have a history of parasomnia and a family history of sleepwalking. Sexual behaviour during a sleep automatism can vary from explicit sexual vocalisations, to violent masturbation, to complex sexual acts including anal, oral and vaginal penetration. A recent case in England is reported where the defendant was acquitted on 3 charges of rape on the basis of automatism due to somnambulistic sexual behaviour.

  5. Genetics of impulsive behaviour.

    PubMed

    Bevilacqua, Laura; Goldman, David

    2013-01-01

    Impulsivity, defined as the tendency to act without foresight, comprises a multitude of constructs and is associated with a variety of psychiatric disorders. Dissecting different aspects of impulsive behaviour and relating these to specific neurobiological circuits would improve our understanding of the etiology of complex behaviours for which impulsivity is key, and advance genetic studies in this behavioural domain. In this review, we will discuss the heritability of some impulsivity constructs and their possible use as endophenotypes (heritable, disease-associated intermediate phenotypes). Several functional genetic variants associated with impulsive behaviour have been identified by the candidate gene approach and re-sequencing, and whole genome strategies can be implemented for discovery of novel rare and common alleles influencing impulsivity. Via deep sequencing an uncommon HTR2B stop codon, common in one population, was discovered, with implications for understanding impulsive behaviour in both humans and rodents and for future gene discovery.

  6. Genetics of impulsive behaviour

    PubMed Central

    Bevilacqua, Laura; Goldman, David

    2013-01-01

    Impulsivity, defined as the tendency to act without foresight, comprises a multitude of constructs and is associated with a variety of psychiatric disorders. Dissecting different aspects of impulsive behaviour and relating these to specific neurobiological circuits would improve our understanding of the etiology of complex behaviours for which impulsivity is key, and advance genetic studies in this behavioural domain. In this review, we will discuss the heritability of some impulsivity constructs and their possible use as endophenotypes (heritable, disease-associated intermediate phenotypes). Several functional genetic variants associated with impulsive behaviour have been identified by the candidate gene approach and re-sequencing, and whole genome strategies can be implemented for discovery of novel rare and common alleles influencing impulsivity. Via deep sequencing an uncommon HTR2B stop codon, common in one population, was discovered, with implications for understanding impulsive behaviour in both humans and rodents and for future gene discovery. PMID:23440466

  7. Nuclear Quadrupole Coupling Tensors of 2H in the a-Alum RbAl(SO4)2 · 12D2O and the Dynamical Behaviour of the D2O Molecules. An Investigation by NMR and IR

    NASA Astrophysics Data System (ADS)

    Ramakrishna, J.; Weiden, Norbert; Weiss, Alarich

    1990-04-01

    By single crystal NMR the nuclear quadrupole coupling constants eQΦzz h-1 (2H), the asymmetry parameters η(2H) and the direction cosines of the principal axes of the electric field gradient tensors of the 2H atoms of the two kinds of D2O molecules have been determined at 295 K in RbAl(SO4)2 · 12D2O. The results show that the D2O molecules surrounding the ion Al3+ are "static" within the time scale of the 2H nuclear quadrupole interaction while the D2O belonging to the octahedron around the Rb+ undergoes fast reorientations around the twofold molecular axis. For the two kinds of D2O in the alum we found: eQΦzz(1)h-1 (2H) = 186.5 kHz, η(1),(2H) = 0.1234; eQΦzz(2)h-1 (2H) = 169.7 kHz,η (2)(2H) = 0.1297; eQΦzz(3)h-1(2H) = 122.1 kHz, (2H) = 0.8087. eQΦzz(1) and eQΦzz(2) belong to the "static" D2O molecules and an assignment to the two different 2H atoms has been performed. The IR spectra of RbAl(SO4)2 · 12(H1-xDx)2O have been investigated, and for the O - D stretching frequencies values of 2145 cm-1 , 2235 cm-1 , 2470 cm-1 and 2525 cm -1 have been obtained. They agree well with the relations between ṽOD and eQΦzz h-1(2H) given in the literature.

  8. Nonadiabatic Coupling

    NASA Astrophysics Data System (ADS)

    Kryachko, Eugene S.

    The general features of the nonadiabatic coupling and its relation to molecular properties are surveyed. Some consequences of the [`]equation of motion', formally expressing a [`]smoothness' of a given molecular property within the diabatic basis, are demonstrated. A particular emphasis is made on the relation between a [`]smoothness' of the electronic dipole moment and the generalized Mulliken-Hush formula for the diabatic electronic coupling.

  9. Applying One Health to behaviour.

    PubMed

    Bower, Caroline

    2014-11-08

    The British Veterinary Behaviour Association and the Association of Pet Behaviour Counsellors held a meeting last month to highlight the One Health principle with regard to the behaviour of people and animals, particularly pets. Caroline Bower reports. British Veterinary Association.

  10. Sedentary behaviour in youth.

    PubMed

    Pate, Russell R; Mitchell, Jonathan A; Byun, Wonwoo; Dowda, Marsha

    2011-09-01

    The purpose of this review is to describe the amount of time children spend in sedentary behaviour and to determine if there are specific factors that associate with sedentary behaviour in children. The following search terms were used to identify relevant articles: sedentary behaviour, inactivity, television, computer, video games, small screen, sitting, prevalence, patterns, correlates, factors and determinants. The databases used to conduct the search included PubMed, PsycINFO, ERIC (Education Resources Information Center) and Academic Search Premier. The studies reviewed were limited to those that sampled children (2-18 years), were written in English and used a measure of sedentary behaviour as the dependent variable. Several studies reported the time spent watching television or the proportion of children at or above a threshold for television viewing (eg, ≥3 h/day). Among the accelerometer studies included, the National Health and Nutrition Examination Survey is the largest and reported ∼6.1, 7.5 and 8.0 h/day mean sedentary time in children 6-11, 12-15 and 16-19 years old, respectively. Taken together, the existing literature across the world indicates a slightly higher level of sedentary behaviour in older children. Higher levels of sedentary behaviour were also reported in non-white children, children from lower socioeconomic status background and children from households with more access to televisions/computers. Lower levels of sedentary behaviour were reported in children whose parents have rules/limitations on screen time.

  11. Fatigue behaviour of composites

    NASA Astrophysics Data System (ADS)

    Hartwig, G.; Hübner, R.; Knaak, S.; Pannkoke, C.

    An important design parameter for cyclically loaded structures (e.g. transport vessels) is the fatigue endurance limit. The cryogenic fatigue behaviour with different types of fibres and matrices has been investigated. The main emphasis it put on the behaviour of fibre dominated properties. It is surprising that the fatigue strength even of unidirectional fibre composites is strongly influenced by the matrix type. This will be discussed for carbon fibre composites with thermoplastic and duroplastic matrices under tensile and shear loading. For crossplies (with non-woven fabrics) the interaction between laminates controls the fatigue behaviour. The interaction depends on the matrix type and is different for tensile and shear loading.

  12. Cognitive science and behaviourism.

    PubMed

    Skinner, B F

    1985-08-01

    In this paper it is argued that cognitive scientists, claiming the support of brain science and computer simulation, have revived a traditional view that behaviour is initiated by an internal, autonomous mind. In doing so, they have misused the metaphor of storage and retrieval, given neurology a misleading assignment, frequently replaced controlled experimental conditions with mere descriptions of conditions and the assessment of behaviour with statements of expectations and intentions, given feelings and states of mind the status of causes of behaviour rather than the products of the causes, and failed to define many key terms in dimensions acceptable to science.

  13. Boundary Critical Behaviour of Two-Dimensional Layered Ising Models

    NASA Astrophysics Data System (ADS)

    Pelizzola, Alessandro

    Layered models are models in which the coupling constants depend in an arbitrary way on one spatial coordinate, usually the distance from a free surface or boundary. Here the theory of the boundary critical behaviour of two-dimensional layered Ising models, including the Hilhorst-van Leeuwen model and models for aperiodic systems, is reviewed, with a particular attention to exact results for the critical behaviour and the boundary order parameter.

  14. Early ant trajectories: spatial behaviour before behaviourism.

    PubMed

    Wehner, Rüdiger

    2016-04-01

    In the beginning of the twentieth century, when Jacques Loeb's and John Watson's mechanistic view of life started to dominate animal physiology and behavioural biology, several scientists with different academic backgrounds got engaged in studying the wayfinding behaviour of ants. Largely unaffected by the scientific spirit of the time, they worked independently of each other in different countries: in Algeria, Tunisia, Spain, Switzerland and the United States of America. In the current literature on spatial cognition these early ant researchers--Victor Cornetz, Felix Santschi, Charles Turner and Rudolf Brun--are barely mentioned. Moreover, it is virtually unknown that the great neuroanatomist Santiago Ramón y Cajal had also worked on spatial orientation in ants. This general neglect is certainly due to the fact that nearly all these ant researchers were scientific loners, who did their idiosyncratic investigations outside the realm of comparative physiology, neurobiology and the behavioural sciences of the time, and published their results in French, German, and Spanish at rather inaccessible places. Even though one might argue that much of their work resulted in mainly anecdotal evidence, the conceptual approaches of these early ant researchers preempt much of the present-day discussions on spatial representation in animals.

  15. Psychology: Inducing green behaviour

    NASA Astrophysics Data System (ADS)

    Thøgersen, John

    2013-02-01

    Economic arguments, such as saving money, are often used to promote pro-environmental actions -- for example, reducing energy use. However, research shows that people's environmental motives are sometimes better drivers of behavioural change.

  16. Equine learning behaviour.

    PubMed

    Murphy, Jack; Arkins, Sean

    2007-09-01

    Scientists and equestrians continually seek to achieve a clearer understanding of equine learning behaviour and its implications for training. Behavioural and learning processes in the horse are likely to influence not only equine athletic success but also the usefulness of the horse as a domesticated species. However given the status and commercial importance of the animal, equine learning behaviour has received only limited investigation. Indeed most experimental studies on equine cognitive function to date have addressed behaviour, learning and conceptualization processes at a moderately basic cognitive level compared to studies in other species. It is however, likely that the horses with the greatest ability to learn and form/understand concepts are those, which are better equipped to succeed in terms of the human-horse relationship and the contemporary training environment. Within equitation generally, interpretation of the behavioural processes and training of the desired responses in the horse are normally attempted using negative reinforcement strategies. On the other hand, experimental designs to actually induce and/or measure equine learning rely almost exclusively on primary positive reinforcement regimes. Employing two such different approaches may complicate interpretation and lead to difficulties in identifying problematic or undesirable behaviours in the horse. The visual system provides the horse with direct access to immediate environmental stimuli that affect behaviour but vision in the horse is of yet not fully investigated or understood. Further investigations of the equine visual system will benefit our understanding of equine perception, cognitive function and the subsequent link with learning and training. More detailed comparative investigations of feral or free-ranging and domestic horses may provide useful evidence of attention, stress and motivational issues affecting behavioural and learning processes in the horse. The challenge for

  17. Wave behaviour and noncomplementary particle behaviour in the same experiment

    NASA Astrophysics Data System (ADS)

    Rangwala, Sadiq; Roy, S. M.

    1994-07-01

    Grangier, Roger and Aspect have recently performed beautiful experiments, which show that the same single photon source shows wave behaviour or particle behaviour depending on the experimental arrangement. We propose experiments in which quantum mechanics predicts wave behaviour and noncomplementary particle behaviour in the same experiment.

  18. FLEXIBLE COUPLING

    DOEpatents

    Babelay, E.F.

    1962-02-13

    A flexible shaft coupling for operation at speeds in excess of 14,000 rpm is designed which requires no lubrication. A driving sleeve member and a driven sleeve member are placed in concentric spaced relationship. A torque force is transmitted to the driven member from the driving member through a plurality of nylon balls symmetrically disposed between the spaced sleeves. The balls extend into races and recesses within the respective sleeve members. The sleeve members have a suitable clearance therebetween and the balls have a suitable radial clearance during operation of the coupling to provide a relatively loose coupling. These clearances accommodate for both parallel and/or angular misalignments and avoid metal-tometal contact between the sleeve members during operation. Thus, no lubrication is needed, and a minimum of vibrations is transmitted between the sleeve members. (AEC)

  19. Prosthesis coupling

    NASA Technical Reports Server (NTRS)

    Reswick, J. B.; Mooney, V.; Bright, C. W.; Owens, L. J. (Inventor)

    1979-01-01

    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump.

  20. Velocity dependant splash behaviour

    NASA Astrophysics Data System (ADS)

    Hamlett, C. A. E.; Shirtcliffe, N. J.; McHale, G.; Ahn, S.; Doerr, S. H.; Bryant, R.; Newton, M. I.

    2012-04-01

    Extreme soil water repellency can occur in nature via condensation of volatile organic compounds released during wildfires and can lead to increased erosion rate. Such extreme water repellent soil can be classified as superhydrophobic and shares similar chemical and topographical features to specifically designed superhydrophobic surfaces. Previous studies using high speed videography to investigate single droplet impact behaviour on artificial superhydrophobic have revealed three distinct modes of splash behaviour (rebound, pinned and fragmentation) which are dependent on the impact velocity of the droplet. In our studies, using high-speed videography, we show that such splash behaviour can be replicated on fixed 'model' water repellent soils (hydrophobic glass beads/particles). We show that the type of splash behaviour is dependent on both the size and chemical nature of the fixed particles. The particle shape also influences the splash behaviour as shown by drop impact experiments on fixed sand samples. We have also studied soil samples, as collected from the field, which shows that the type of droplet splash behaviour can lead to enhanced soil particle transport.

  1. CO{sub 2} Geologic Storage: Coupled Hydro-Chemo-Thermo-Mechanical Phenomena - From Pore-scale Processes to Macroscale Implications -

    SciTech Connect

    Santamarina, J. Carlos

    2013-05-31

    Global energy consumption will increase in the next decades and it is expected to largely rely on fossil fuels. The use of fossil fuels is intimately related to CO{sub 2} emissions and the potential for global warming. Geological CO{sub 2} storage aims to mitigate the global warming problem by sequestering CO{sub 2} underground. Coupled hydro-chemo-mechanical phenomena determine the successful operation and long term stability of CO{sub 2} geological storage. This research explores coupled phenomena, identifies different zones in the storage reservoir, and investigates their implications in CO{sub 2} geological storage. In particular, the research: Explores spatial patterns in mineral dissolution and precipitation (comprehensive mass balance formulation); experimentally determines the interfacial properties of water, mineral, and CO{sub 2} systems (including CO{sub 2}-water-surfactant mixtures to reduce the CO{sub 2}- water interfacial tension in view of enhanced sweep efficiency); analyzes the interaction between clay particles and CO{sub 2}, and the response of sediment layers to the presence of CO{sub 2} using specially designed experimental setups and complementary analyses; couples advective and diffusive mass transport of species, together with mineral dissolution to explore pore changes during advection of CO{sub 2}-dissolved water along a rock fracture; upscales results to a porous medium using pore network simulations; measures CO{sub 2} breakthrough in highly compacted fine-grained sediments, shale and cement specimens; explores sealing strategies; and experimentally measures CO{sub 2}-CH{sub 4} replacement in hydrate-bearing sediments during. Analytical, experimental and numerical results obtained in this study can be used to identify optimal CO{sub 2} injection and reservoir-healing strategies to maximize the efficiency of CO{sub 2} injection and to attain long-term storage.

  2. The couple as context: Latino gay male couples and HIV.

    PubMed

    Beougher, Sean C; Gomez, Walter; Hoff, Colleen C

    2011-03-01

    HIV-prevention efforts with gay men in relationships frequently omit primary partners. When they are considered, examinations of race/ethnicity are often overlooked despite higher infection rates among gay men of colour. Acknowledging both the need to contextualise the behaviours that may affect HIV risk for gay men of colour and the disproportionate impact of HIV on Latino gay men, the present study utilised semi-structured, qualitative interviews to explore relationship dynamics, sexual agreements and behaviours, safer sex choices and HIV risk among nine Latino gay male couples. All participants were HIV-negative and in concordant negative relationships. Additionally, nearly all reported closed agreements. Analysis revealed participants engaging in four behaviours that may actively reduce their HIV risk: approaching sexual agreements from a practical standpoint, maintaining a high literacy around HIV, having exposure to social support groups for Latino gay men and finding support in their relationship with another Latino gay man. Additional issues are raised where long-term HIV prevention is concerned. Intimate relationships are an important context for understanding both HIV risk and prevention among Latino gay men. Likewise, race/ethnicity provides an indispensable perspective on all research with gay couples. Future prevention efforts with gay men must strive to include both.

  3. The couple as context: Latino gay male couples and HIV

    PubMed Central

    Beougher, Sean C.; Gómez, Walter; Hoff, Colleen C.

    2011-01-01

    HIV prevention efforts with gay men in relationships frequently omit primary partners. When they are considered, examinations of race/ethnicity are often overlooked despite higher infection rates among gay men of colour. Acknowledging both the need to contextualise the behaviours that may affect HIV risk for gay men of colour and the disproportionate impact of HIV on Latino gay men, the present study utilised semi-structured, qualitative interviews to explore relationship dynamics, sexual agreements and behaviours, and safer sex choices and HIV risk among nine Latino gay male couples. All participants were HIV-negative and in concordant negative relationships. Additionally, nearly all reported closed agreements. Analysis revealed participants engaging in four behaviours that may actively reduce their HIV risk: approaching sexual agreements from a practical standpoint, maintaining a high literacy around HIV, having exposure to social support groups for Latino gay men, and finding support in their relationship with another Latino gay man. Additional issues are raised where long-term HIV prevention is concerned. Intimate relationships are an important context for understanding both HIV risk and prevention among Latino gay men. Likewise, race/ethnicity provides an indispensable perspective on all research with gay couples. Future prevention efforts with gay men must strive to include both. PMID:21082463

  4. A Financial Market Model Incorporating Herd Behaviour

    PubMed Central

    2016-01-01

    Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informational cascades in the presence of information thresholds is used to construct a new model of asset price returns that allows for both quiescent and herd-like regimes. Agent interaction is modelled using a stochastic pulse-coupled network, parametrised by information thresholds and a network coupling probability. Agents may possess either one or two information thresholds that, in each case, determine the number of distinct states an agent may occupy before trading takes place. In the case where agents possess two thresholds (labelled as the finite state-space model, corresponding to agents’ accumulating information over a bounded state-space), and where coupling strength is maximal, an asymptotic expression for the cascade-size probability is derived and shown to follow a power law when a critical value of network coupling probability is attained. For a range of model parameters, a mixture of negative binomial distributions is used to approximate the cascade-size distribution. This approximation is subsequently used to express the volatility of model price returns in terms of the model parameter which controls the network coupling probability. In the case where agents possess a single pulse-coupling threshold (labelled as the semi-infinite state-space model corresponding to agents’ accumulating information over an unbounded state-space), numerical evidence is presented that demonstrates volatility clustering and long-memory patterns in the volatility of asset returns. Finally, output from the model is compared to both the distribution of historical stock returns and the

  5. A Financial Market Model Incorporating Herd Behaviour.

    PubMed

    Wray, Christopher M; Bishop, Steven R

    2016-01-01

    Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informational cascades in the presence of information thresholds is used to construct a new model of asset price returns that allows for both quiescent and herd-like regimes. Agent interaction is modelled using a stochastic pulse-coupled network, parametrised by information thresholds and a network coupling probability. Agents may possess either one or two information thresholds that, in each case, determine the number of distinct states an agent may occupy before trading takes place. In the case where agents possess two thresholds (labelled as the finite state-space model, corresponding to agents' accumulating information over a bounded state-space), and where coupling strength is maximal, an asymptotic expression for the cascade-size probability is derived and shown to follow a power law when a critical value of network coupling probability is attained. For a range of model parameters, a mixture of negative binomial distributions is used to approximate the cascade-size distribution. This approximation is subsequently used to express the volatility of model price returns in terms of the model parameter which controls the network coupling probability. In the case where agents possess a single pulse-coupling threshold (labelled as the semi-infinite state-space model corresponding to agents' accumulating information over an unbounded state-space), numerical evidence is presented that demonstrates volatility clustering and long-memory patterns in the volatility of asset returns. Finally, output from the model is compared to both the distribution of historical stock returns and the market

  6. Imitation and utilisation behaviour.

    PubMed Central

    De Renzi, E; Cavalleri, F; Facchini, S

    1996-01-01

    OBJECTIVE: To investigate the incidence, anatomical correlates, and clinical features of imitation and utilisation behaviour, which are thought by Lhermitte and coworkers to represent a reliable and frequent index of frontal lobe disease. METHODS: 78 patients with hemispheric local lesions were tested in two separate sessions, in which their reactions to a series of gestures performed by the examiner and to the presentation of a set of objects were recorded. The patients were stratified into a frontal (n = 52) and a non-frontal group (n = 26) on the basis of their CT data. RESULTS AND CONCLUSIONS: Imitation behaviour was present in 39% of the frontal patients and was mainly associated with medial and lateral lesions, at odds with the claim of Lhermitte et al that it is a constant accompaniment of lower, mediobasal lesions. In the non-frontal group it was found in three patients, all with damage to the deep nuclei region. Utilisation behaviour was a much rarer phenomenon, present in only two patients, both of whom had frontal damage. Neither imitation behaviour nor utilisation behaviour were found in patients with retrorolandic cortical lesions. PMID:8890779

  7. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  8. Restoration of rhythmicity in diffusively coupled dynamical networks.

    PubMed

    Zou, Wei; Senthilkumar, D V; Nagao, Raphael; Kiss, István Z; Tang, Yang; Koseska, Aneta; Duan, Jinqiao; Kurths, Jürgen

    2015-07-15

    Oscillatory behaviour is essential for proper functioning of various physical and biological processes. However, diffusive coupling is capable of suppressing intrinsic oscillations due to the manifestation of the phenomena of amplitude and oscillation deaths. Here we present a scheme to revoke these quenching states in diffusively coupled dynamical networks, and demonstrate the approach in experiments with an oscillatory chemical reaction. By introducing a simple feedback factor in the diffusive coupling, we show that the stable (in)homogeneous steady states can be effectively destabilized to restore dynamic behaviours of coupled systems. Even a feeble deviation from the normal diffusive coupling drastically shrinks the death regions in the parameter space. The generality of our method is corroborated in diverse non-linear systems of diffusively coupled paradigmatic models with various death scenarios. Our study provides a general framework to strengthen the robustness of dynamic activity in diffusively coupled dynamical networks.

  9. Restoration of rhythmicity in diffusively coupled dynamical networks

    PubMed Central

    Zou, Wei; Senthilkumar, D. V.; Nagao, Raphael; Kiss, István Z.; Tang, Yang; Koseska, Aneta; Duan, Jinqiao; Kurths, Jürgen

    2015-01-01

    Oscillatory behaviour is essential for proper functioning of various physical and biological processes. However, diffusive coupling is capable of suppressing intrinsic oscillations due to the manifestation of the phenomena of amplitude and oscillation deaths. Here we present a scheme to revoke these quenching states in diffusively coupled dynamical networks, and demonstrate the approach in experiments with an oscillatory chemical reaction. By introducing a simple feedback factor in the diffusive coupling, we show that the stable (in)homogeneous steady states can be effectively destabilized to restore dynamic behaviours of coupled systems. Even a feeble deviation from the normal diffusive coupling drastically shrinks the death regions in the parameter space. The generality of our method is corroborated in diverse non-linear systems of diffusively coupled paradigmatic models with various death scenarios. Our study provides a general framework to strengthen the robustness of dynamic activity in diffusively coupled dynamical networks. PMID:26173555

  10. Viability of nonminimally coupled f (R) gravity

    NASA Astrophysics Data System (ADS)

    Bertolami, Orfeu; Páramos, Jorge

    2016-03-01

    In this work we explore the viability of nonminimally coupled matter-curvature gravity theories, namely the conditions required for the absence of tachyon instabilities and ghost degrees of freedom. We contrast our finds with recent claims of a pathological behaviour of this class of models, which resorted to, in our view, an incorrect analogy with k-essence.

  11. Rheological behaviour of nanofluids

    NASA Astrophysics Data System (ADS)

    Chen, Haisheng; Ding, Yulong; Tan, Chunqing

    2007-10-01

    This work aims at a more fundamental understanding of the rheological behaviour of nanofluids and the interpretation of the discrepancy in the recent literature. Both experiments and theoretical analyses are carried out with the experimental work on ethylene glycol (EG)-based nanofluids containing 0.5-8.0 wt% spherical TiO2 nanoparticles at 20-60 °C and the theoretical analyses on the high shear viscosity, shear thinning behaviour and temperature dependence. The experimental results show that the EG-based nanofluids are Newtonian under the conditions of this work with the shear viscosity as a strong function of temperature and particle concentration. The relative viscosity of the nanofluids is, however, independent of temperature. The theoretical analyses show that the high shear viscosity of nanofluids can be predicted by the Krieger-Dougherty equation if the effective nanoparticle concentration is used. For spherical nanoparticles, an aggregate size of approximately 3 times the primary nanoparticle size gives the best prediction of experimental data of both this work and those from the literature. The shear thinning behaviour of nanofluids depends on the effective particle concentration, the range of shear rate and viscosity of the base liquid. Such non-Newtonian behaviour can be characterized by a characteristic shear rate, which decreases with increasing volume fraction, increasing base liquid viscosity, or increasing aggregate size. These findings explain the reported controversy of the rheological behaviour of nanofluids in the literature. At temperatures not very far from the ambient temperature, the relative high shear viscosity is independent of temperature due to negligible Brownian diffusion in comparison to convection in high shear flows, in agreement with the experimental results. However, the characteristic shear rate can have strong temperature dependence, thus affecting the shear thinning behaviour. The theoretical analyses also lead to a

  12. Cephalopod consciousness: behavioural evidence.

    PubMed

    Mather, Jennifer A

    2008-03-01

    Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and tactile cues, and may have domain generality and form simple concepts. Third, these animals are aware of their position, both within themselves and in larger space, including having a working memory of foraging areas in the recent past. Thus if using a 'global workspace' which evaluates memory input and focuses attention is the criterion, cephalopods appear to have primary consciousness.

  13. Behaviour Centred Design: towards an applied science of behaviour change.

    PubMed

    Aunger, Robert; Curtis, Valerie

    2016-12-01

    Behaviour change has become a hot topic. We describe a new approach, Behaviour Centred Design (BCD), which encompasses a theory of change, a suite of behavioural determinants and a programme design process. The theory of change is generic, assuming that successful interventions must create a cascade of effects via environments, through brains, to behaviour and hence to the desired impact, such as improved health. Changes in behaviour are viewed as the consequence of a reinforcement learning process involving the targeting of evolved motives and changes to behaviour settings, and are produced by three types of behavioural control mechanism (automatic, motivated and executive). The implications are that interventions must create surprise, revalue behaviour and disrupt performance in target behaviour settings. We then describe a sequence of five steps required to design an intervention to change specific behaviours: Assess, Build, Create, Deliver and Evaluate. The BCD approach has been shown to change hygiene, nutrition and exercise-related behaviours and has the advantages of being applicable to product, service or institutional design, as well as being able to incorporate future developments in behaviour science. We therefore argue that BCD can become the foundation for an applied science of behaviour change.

  14. Behaviour Centred Design: towards an applied science of behaviour change

    PubMed Central

    Aunger, Robert; Curtis, Valerie

    2016-01-01

    ABSTRACT Behaviour change has become a hot topic. We describe a new approach, Behaviour Centred Design (BCD), which encompasses a theory of change, a suite of behavioural determinants and a programme design process. The theory of change is generic, assuming that successful interventions must create a cascade of effects via environments, through brains, to behaviour and hence to the desired impact, such as improved health. Changes in behaviour are viewed as the consequence of a reinforcement learning process involving the targeting of evolved motives and changes to behaviour settings, and are produced by three types of behavioural control mechanism (automatic, motivated and executive). The implications are that interventions must create surprise, revalue behaviour and disrupt performance in target behaviour settings. We then describe a sequence of five steps required to design an intervention to change specific behaviours: Assess, Build, Create, Deliver and Evaluate. The BCD approach has been shown to change hygiene, nutrition and exercise-related behaviours and has the advantages of being applicable to product, service or institutional design, as well as being able to incorporate future developments in behaviour science. We therefore argue that BCD can become the foundation for an applied science of behaviour change. PMID:27535821

  15. Infertility, infertility treatment and behavioural problems in the offspring.

    PubMed

    Zhu, Jin Liang; Obel, Carsten; Basso, Olga; Henriksen, Tine B; Bech, Bodil H; Hvidtjørn, Dorte; Olsen, Jørn

    2011-09-01

    Behavioural patterns in children of infertile couples may be influenced by both the underlying causes of infertility and stress in the couples. Treatment procedures, such as culture media and manipulation of gametes and embryos, may also result in developmental problems. We examined behavioural problems in children as a function of infertility and infertility treatment, using data from three population-based birth cohorts in Denmark (Aalborg-Odense Birth Cohort, Aarhus Birth Cohort and Danish National Birth Cohort). Information on time to pregnancy and infertility treatment was collected during pregnancy. Children aged between 7 and 21 years were assessed using the Strengths and Difficulties Questionnaire (SDQ). The SDQ was completed by mothers in all cohorts and, in addition, by teachers in the Aarhus cohort and by children themselves in the Aalborg-Odense cohort. Children born after a time to pregnancy of >12 months and no infertility treatment had a behavioural pattern similar to children of fertile parents. Teachers reported a higher total difficulties score for children born after infertility treatment, but no significant differences were seen on any subscales of the teachers' report, and neither the mothers nor the children reported any differences on the total difficulties score and the prosocial behaviour score. Our results are thus overall reassuring regarding behavioural problems in children born to infertile couples, regardless of infertility treatment.

  16. Challenging Student Behaviour

    ERIC Educational Resources Information Center

    Jones, Glyn; Philp, Clare

    2011-01-01

    The issue of poor student behaviour within higher education institutions (HEIs) has been well documented in recent years. Although the number of reported cases constitutes a very small percentage of the overall student population in the UK, the impact of student misconduct on the rest of the student body and staff in HEIs can be substantial. For…

  17. Modelling cellular behaviour

    NASA Astrophysics Data System (ADS)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  18. Locomotion and postural behaviour

    NASA Astrophysics Data System (ADS)

    Schmidt, M.

    2010-05-01

    The purpose of this article is to provide a survey of the diversity of primate locomotor behaviour for people who are involved in research using laboratory primates. The main locomotor modes displayed by primates are introduced with reference to some general morphological adaptations. The relationships between locomotor behaviour and body size, habitat structure and behavioural context will be illustrated because these factors are important determinants of the evolutionary diversity of primate locomotor activities. They also induce the high individual plasticity of the locomotor behaviour for which primates are well known. The article also provides a short overview of the preferred locomotor activities in the various primate families. A more detailed description of locomotor preferences for some of the most common laboratory primates is included which also contains information about substrate preferences and daily locomotor activities which might useful for laboratory practice. Finally, practical implications for primate husbandry and cage design are provided emphasizing the positive impact of physical activity on health and psychological well-being of primates in captivity.

  19. Tubular Coupling

    NASA Technical Reports Server (NTRS)

    Rosenbaum, Bernard J. (Inventor)

    2000-01-01

    A system for coupling a vascular overflow graft or cannula to a heart pump. A pump pipe outlet is provided with an external tapered surface which receives the end of a compressible connula. An annular compression ring with a tapered internal bore surface is arranged about the cannula with the tapered internal surface in a facing relationship to the external tapered surface. The angle of inclination of the tapered surfaces is converging such that the spacing between the tapered surfaces decreases from one end of the external tapered surface to the other end thereby providing a clamping action of the tapered surface on a cannula which increases as a function of the length of cannula segment between the tapered surfaces. The annular compression ring is disposed within a tubular locking nut which threadedly couples to the pump and provides a compression force for urging the annular ring onto the cannula between the tapered surfaces. The nut has a threaded connection to the pump body. The threaded coupling to the pump body provides a compression force for the annular ring. The annular ring has an annular enclosure space in which excess cannula material from the compression between the tapered surfaces to "bunch up" in the space and serve as an enlarged annular ring segment to assist holding the cannula in place. The clamped cannula provides a seamless joint connection to the pump pipe outlet where the clamping force is uniformly applied to the cannula because of self alignment of the tapered surfaces. The nut can be easily disconnected to replace the pump if necessary.

  20. Longitudinal Links between Early Coparenting and Infant Behaviour Problems

    ERIC Educational Resources Information Center

    LeRoy, Michelle; Mahoney, Annette; Pargament, Kenneth I.; DeMaris, Alfred

    2013-01-01

    This study of 164 married couples examined longitudinal links between parents' perceptions of coparenting support and undermining by spouse at 6 months postpartum and infant behaviour problems at the age of 12 months after controlling for marital quality, individual parenting, and infant temperament. Multiple methods (i.e. parent reports and…

  1. The evolution of behaviour therapy and cognitive behaviour therapy.

    PubMed

    Rachman, S

    2015-01-01

    The historical background of the development of behaviour therapy is described. It was based on the prevailing behaviourist psychology and constituted a fundamentally different approach to the causes and treatment of psychological disorders. It had a cold reception and the idea of treating the behaviour of neurotic and other patients was regarded as absurd. The opposition of the medical profession and psychoanalysts is explained. Parallel but different forms of behaviour therapy developed in the US and UK. The infusion of cognitive concepts and procedures generated a merger of behaviour therapy and cognitive therapy, cognitive behaviour therapy (CBT). The strengths and limitations of the early and current approaches are evaluated.

  2. Defining and treating challenging behaviour.

    PubMed

    Tarbuck, P; Thompson, T

    Behavioural disorders present extreme problems for clients and careers. In this article, the authors discuss a definition of challenging behaviour. Types of behaviour classified as 'challenging' and possible responses to them, are also considered. Some of the points are illustrated with short case studies.

  3. Dark coupling

    SciTech Connect

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S. E-mail: d.hernandez@uam.es E-mail: omena@ific.uv.es

    2009-07-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed.

  4. Thermoacoustic couple

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-10-04

    An apparatus and method for determining acoustic power density level and its direction in a fluid using a single sensor are disclosed. The preferred embodiment of the apparatus, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  5. The behavioural ecology of irrational behaviours.

    PubMed

    Huneman, Philippe; Martens, Johannes

    2017-08-17

    Natural selection is often envisaged as the ultimate cause of the apparent rationality exhibited by organisms in their specific habitat. Given the equivalence between selection and rationality as maximizing processes, one would indeed expect organisms to implement rational decision-makers. Yet, many violations of the clauses of rationality have been witnessed in various species such as starlings, hummingbirds, amoebas and honeybees. This paper attempts to interpret such discrepancies between economic rationality (defined by the main axioms of rational choice theory) and biological rationality (defined by natural selection). After having distinguished two kinds of rationality we introduce irrationality as a negation of economic rationality by biologically rational decision-makers. Focusing mainly on those instances of irrationalities that can be understood as exhibiting inconsistency in making choices, i.e. as non-conformity of a given behaviour to axioms such as transitivity or independence of irrelevant alternatives, we propose two possible families of Darwinian explanations that may account for these apparent irrationalities. First, we consider cases where natural selection may have been an indirect cause of irrationality. Second, we consider putative cases where violations of rationality axioms may have been directly favored by natural selection. Though the latter cases (prima facie) seem to clearly contradict our intuitive representation of natural selection as a process that maximizes fitness, we argue that they are actually unproblematic; for often, they can be redescribed as cases where no rationality axiom is violated, or as situations where no adaptive solution exists in the first place.

  6. Effects of chemo-mechanical polishing on CdZnTe X-ray and gamma-ray detectors

    DOE PAGES

    Egarievwe, Stephen E.; Hossain, Anwar; Okwechime, Ifechukwude O.; ...

    2015-06-23

    Here, mechanically polishing cadmium zinc telluride (CdZnTe) wafers for x-ray and gamma-ray detectors often is inadequate in removing surface defects caused by cutting them from the ingots. Fabrication-induced defects, such as surface roughness, dangling bonds, and nonstoichiometric surfaces, often are reduced through polishing and etching the surface. In our earlier studies of mechanical polishing with alumina powder, etching with hydrogen bromide in hydrogen peroxide solution, and chemomechanical polishing with bromine–methanol–ethylene glycol solution, we found that the chemomechanical polishing process produced the least surface leakage current. In this research, we focused on using two chemicals to chemomechanically polish CdZnTe wafers aftermore » mechanical polishing, viz. bromine–methanol–ethylene glycol (BME) solution, and hydrogen bromide (HBr) in a hydrogen peroxide and ethylene–glycol solution. We used x-ray photoelectron spectroscopy (XPS), current–voltage (I–V) measurements, and Am-241 spectral response measurements to characterize and compare the effects of each solution. The results show that the HBr-based solution produced lower leakage current than the BME solution. Results from using the same chemomechanical polishing solution on two samples confirmed that the surface treatment affects the measured bulk current (a combination of bulk and surface currents). XPS results indicate that the tellurium oxide to tellurium peak ratios for the mechanical polishing process were reduced significantly by chemomechanical polishing using the BME solution (78.9% for Te 3d5/2O2 and 76.7% for Te 3d3/2O2) compared with the HBr-based solution (27.6% for Te 3d5/2O2 and 35.8% for Te 3d3/2O2). Spectral response measurements showed that the 59.5-keV peak of Am-241 remained under the same channel number for all three CdZnTe samples. While the BME-based solution gave a better performance of 7.15% full-width at half-maximum (FWHM) compared with 7.59% FWHM for the HBr-based solution, the latter showed a smaller variation in performance of 0.39% FWHM over 7 days compared with 0.69% for the BME-based solution.« less

  7. Effects of chemo-mechanical polishing on CdZnTe X-ray and gamma-ray detectors

    SciTech Connect

    Egarievwe, Stephen E.; Hossain, Anwar; Okwechime, Ifechukwude O.; Gul, Rubi; James, Ralph B.

    2015-06-23

    Here, mechanically polishing cadmium zinc telluride (CdZnTe) wafers for x-ray and gamma-ray detectors often is inadequate in removing surface defects caused by cutting them from the ingots. Fabrication-induced defects, such as surface roughness, dangling bonds, and nonstoichiometric surfaces, often are reduced through polishing and etching the surface. In our earlier studies of mechanical polishing with alumina powder, etching with hydrogen bromide in hydrogen peroxide solution, and chemomechanical polishing with bromine–methanol–ethylene glycol solution, we found that the chemomechanical polishing process produced the least surface leakage current. In this research, we focused on using two chemicals to chemomechanically polish CdZnTe wafers after mechanical polishing, viz. bromine–methanol–ethylene glycol (BME) solution, and hydrogen bromide (HBr) in a hydrogen peroxide and ethylene–glycol solution. We used x-ray photoelectron spectroscopy (XPS), current–voltage (I–V) measurements, and Am-241 spectral response measurements to characterize and compare the effects of each solution. The results show that the HBr-based solution produced lower leakage current than the BME solution. Results from using the same chemomechanical polishing solution on two samples confirmed that the surface treatment affects the measured bulk current (a combination of bulk and surface currents). XPS results indicate that the tellurium oxide to tellurium peak ratios for the mechanical polishing process were reduced significantly by chemomechanical polishing using the BME solution (78.9% for Te 3d5/2O2 and 76.7% for Te 3d3/2O2) compared with the HBr-based solution (27.6% for Te 3d5/2O2 and 35.8% for Te 3d3/2O2). Spectral response measurements showed that the 59.5-keV peak of Am-241 remained under the same channel number for all three CdZnTe samples. While the BME-based solution gave a better performance of 7.15% full-width at half-maximum (FWHM) compared with 7.59% FWHM for the HBr-based solution, the latter showed a smaller variation in performance of 0.39% FWHM over 7 days compared with 0.69% for the BME-based solution.

  8. Nano-chemo-mechanical signature of conventional oil-well cement systems: Effects of elevated temperature and curing time

    SciTech Connect

    Krakowiak, Konrad J.; Thomas, Jeffrey J.; Musso, Simone; James, Simon; Akono, Ange-Therese; Ulm, Franz-Josef

    2015-01-15

    With ever more challenging (T,p) environments for cementing applications in oil and gas wells, there is a need to identify the fundamental mechanisms of fracture resistant oil well cements. We report results from a multi-technique investigation of behavior and properties of API class G cement and silica-enriched cement systems subjected to hydrothermal curing from 30 °C to 200 °C; including electron probe microanalysis, X-ray diffraction, thermogravimetry analysis, electron microscopy, neutron scattering (SANS), and fracture scratch testing. The results provide a new insight into the link between system chemistry, micro-texture and micro-fracture toughness. We suggest that the strong correlation found between chemically modulated specific surface and fracture resistance can explain the drop in fracture properties of neat oil-well cements at elevated temperatures; the fracture property enhancement in silica-rich cement systems, between 110° and 175 °C; and the drop in fracture properties of such systems through prolonged curing over 1 year at 200 °C.

  9. Single-molecule chemo-mechanical unfolding reveals multiple transition state barriers in a small single-domain protein

    NASA Astrophysics Data System (ADS)

    Guinn, Emily J.; Jagannathan, Bharat; Marqusee, Susan

    2015-04-01

    A fundamental question in protein folding is whether proteins fold through one or multiple trajectories. While most experiments indicate a single pathway, simulations suggest proteins can fold through many parallel pathways. Here, we use a combination of chemical denaturant, mechanical force and site-directed mutations to demonstrate the presence of multiple unfolding pathways in a simple, two-state folding protein. We show that these multiple pathways have structurally different transition states, and that seemingly small changes in protein sequence and environment can strongly modulate the flux between the pathways. These results suggest that in vivo, the crowded cellular environment could strongly influence the mechanisms of protein folding and unfolding. Our study resolves the apparent dichotomy between experimental and theoretical studies, and highlights the advantage of using a multipronged approach to reveal the complexities of a protein's free-energy landscape.

  10. Neurodevelopmental and behavioural paediatrics.

    PubMed

    McDowell, Michael

    2015-01-01

    One of the notable shifts in Paediatrics across the last 50 years has been towards disorders that are chronic and qualitative in nature. In addition to physical health, these impact on childhood development, behaviour and wellbeing. Understanding and management of these problems extends the traditional biological toolkit of paediatrics into the complexities of uncertainties of psychological and social context. In Australasia, the profession has responded with the development of Community Paediatrics as a recognised sub-specialty, of which Neurodevelopmental and Behavioural Paediatrics is an important component. These developments are reviewed along with consideration of future challenges for this field of health care. © 2015 The Author. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  11. Predicting People's Environmental Behaviour: Theory of Planned Behaviour and Model of Responsible Environmental Behaviour

    ERIC Educational Resources Information Center

    Chao, Yu-Long

    2012-01-01

    Using different measures of self-reported and other-reported environmental behaviour (EB), two important theoretical models explaining EB--Hines, Hungerford and Tomera's model of responsible environmental behaviour (REB) and Ajzen's theory of planned behaviour (TPB)--were compared regarding the fit between model and data, predictive ability,…

  12. Predicting People's Environmental Behaviour: Theory of Planned Behaviour and Model of Responsible Environmental Behaviour

    ERIC Educational Resources Information Center

    Chao, Yu-Long

    2012-01-01

    Using different measures of self-reported and other-reported environmental behaviour (EB), two important theoretical models explaining EB--Hines, Hungerford and Tomera's model of responsible environmental behaviour (REB) and Ajzen's theory of planned behaviour (TPB)--were compared regarding the fit between model and data, predictive ability,…

  13. The effect of oxytocin on human-directed social behaviour in dogs (Canis familiaris).

    PubMed

    Kis, Anna; Ciobica, Alin; Topál, József

    2017-08-01

    The oxytocin system has recently received increasing attention due to its effect on complex human behaviours. In parallel to this, over the past couple of decades, the human-analogue social behaviour of dogs has been intensively studied. Combining these two lines of research (e.g. studying the relationship between dog social behaviour and the oxytocin system) is a promising new research area. The present paper reviews the existing literature on how oxytocin is related to different aspects of human-directed social behaviour in dogs. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Ecological implications of behavioural syndromes.

    PubMed

    Sih, Andrew; Cote, Julien; Evans, Mara; Fogarty, Sean; Pruitt, Jonathan

    2012-03-01

    Interspecific trait variation has long served as a conceptual foundation for our understanding of ecological patterns and dynamics. In particular, ecologists recognise the important role that animal behaviour plays in shaping ecological processes. An emerging area of interest in animal behaviour, the study of behavioural syndromes (animal personalities) considers how limited behavioural plasticity, as well as behavioural correlations affects an individual's fitness in diverse ecological contexts. In this article we explore how insights from the concept and study of behavioural syndromes provide fresh understanding of major issues in population ecology. We identify several general mechanisms for how population ecology phenomena can be influenced by a species or population's average behavioural type, by within-species variation in behavioural type, or by behavioural correlations across time or across ecological contexts. We note, in particular, the importance of behavioural type-dependent dispersal in spatial ecology. We then review recent literature and provide new syntheses for how these general mechanisms produce novel insights on five major issues in population ecology: (1) limits to species' distribution and abundance; (2) species interactions; (3) population dynamics; (4) relative responses to human-induced rapid environmental change; and (5) ecological invasions.

  15. Intergenerational linkages in antisocial behaviour.

    PubMed

    Thornberry, Terence P; Freeman-Gallant, Adrienne; Lovegrove, Peter J

    2009-01-01

    A life-course perspective was used to examine whether a parent's adolescent antisocial behaviour increases the chances of his or her child being involved in antisocial behaviour and, if so, the extent to which different aspects of parenting mediate this relationship. It was hypothesised that there will be significant levels of intergenerational continuity in antisocial behaviour when parents have ongoing contact with the child, and that stress from parenting and ineffective parenting styles will mediate this relationship. Longitudinal data from the Rochester Intergenerational Study were used to test these issues in structural equation models for fathers and for mothers. Parental antisocial behaviour is significantly related to child antisocial behaviour for mothers and for fathers who have frequent contact with the child, but not for fathers with infrequent contact. For mothers, the impact of adolescent antisocial behaviour on the child's antisocial behaviour is primarily mediated through parenting stress and effective parenting. For high-contact fathers there are multiple mediating pathways that help explain the impact of their adolescent antisocial behaviour on their child's behaviour. The roots of antisocial behaviour extend back at least to the parent's adolescence, and parenting interventions need to consider these long-term processes.

  16. Suicide and suicidal behaviour

    PubMed Central

    Turecki, Gustavo; Brent, David A.

    2017-01-01

    Summary Suicide is a complex public health problem of global dimension. Suicidal behaviour (SB) shows marked differences between genders, age groups, geographic regions and socio-political realities, and variably associates with different risk factors, underscoring likely etiological heterogeneity. Although there is no effective algorithm to predict suicide in clinical practice, improved recognition and understanding of clinical, psychological, sociological, and biological factors may facilitate the detection of high-risk individuals and assist in treatment selection. Psychotherapeutic, pharmacological, or neuromodulatory treatments of mental disorders can often prevent SB; additionally, regular follow-up of suicide attempters by mental health services is key to prevent future SB. PMID:26385066

  17. The need for a behavioural analysis of behavioural addictions.

    PubMed

    James, Richard J E; Tunney, Richard J

    2017-03-01

    This review discusses research on behavioural addictions (i.e. associative learning, conditioning), with reference to contemporary models of substance addiction and ongoing controversies in the behavioural addictions literature. The role of behaviour has been well explored in substance addictions and gambling but this focus is often absent in other candidate behavioural addictions. In contrast, the standard approach to behavioural addictions has been to look at individual differences, psychopathologies and biases, often translating from pathological gambling indicators. An associative model presently captures the core elements of behavioural addiction included in the DSM (gambling) and identified for further consideration (internet gaming). Importantly, gambling has a schedule of reinforcement that shows similarities and differences from other addictions. While this is more likely than not applicable to internet gaming, it is less clear whether it is so for a number of candidate behavioural addictions. Adopting an associative perspective, this paper translates from gambling to video gaming, in light of the existing debates on this matter and the nature of the distinction between these behaviours. Finally, a framework for applying an associative model to behavioural addictions is outlined, and it's application toward treatment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Clustering and phase synchronization in populations of coupled phase oscillators

    NASA Astrophysics Data System (ADS)

    Cascallares, Guadalupe; Gleiser, Pablo M.

    2015-10-01

    In many species daily rhythms are endogenously generated by groups of coupled neurons that play the role of a circadian pacemaker. The adaptation of the circadian clock to environmental and seasonal changes has been proposed to be regulated by a dual oscillator system. In order to gain insight into this model, we analyzed the synchronization properties of two fully coupled groups of Kuramoto oscillators. Each group has an internal coupling parameter and the interaction between the two groups can be controlled by two parameters allowing for symmetric or non-symmetric coupling. We show that even for such a simple model counterintuitive behaviours take place, such as a global decrease in synchrony when the coupling between the groups is increased. Through a detailed analysis of the local synchronization processes we explain this behaviour.

  19. Inclusive Education: Teachers' Intentions and Behaviour Analysed from the Viewpoint of the Theory of Planned Behaviour

    ERIC Educational Resources Information Center

    Yan, Zi; Sin, Kuen-fung

    2014-01-01

    The theory of planned behaviour (TPB) claims that behaviour can be predicted by behavioural intention and perceived behavioural control, while behavioural intention is a function of attitude towards the behaviour, subjective norm, and perceived behavioural control. This study aims at providing explanation and prediction of teachers' inclusive…

  20. Inclusive Education: Teachers' Intentions and Behaviour Analysed from the Viewpoint of the Theory of Planned Behaviour

    ERIC Educational Resources Information Center

    Yan, Zi; Sin, Kuen-fung

    2014-01-01

    The theory of planned behaviour (TPB) claims that behaviour can be predicted by behavioural intention and perceived behavioural control, while behavioural intention is a function of attitude towards the behaviour, subjective norm, and perceived behavioural control. This study aims at providing explanation and prediction of teachers' inclusive…

  1. Behavioural plasticity in evolving robots.

    PubMed

    Carvalho, Jônata Tyska; Nolfi, Stefano

    2016-12-01

    In this paper, we show how the development of plastic behaviours, i.e., behaviour displaying a modular organisation characterised by behavioural subunits that are alternated in a context-dependent manner, can enable evolving robots to solve their adaptive task more efficiently also when it does not require the accomplishment of multiple conflicting functions. The comparison of the results obtained in different experimental conditions indicates that the most important prerequisites for the evolution of behavioural plasticity are: the possibility to generate and perceive affordances (i.e., opportunities for behaviour execution), the possibility to rely on flexible regulatory processes that exploit both external and internal cues, and the possibility to realise smooth and effective transitions between behaviours.

  2. [Sedentary behaviour and health].

    PubMed

    Füzéki, E; Vogt, L; Banzer, W

    2015-03-01

    Exercise-related public health recommendations and research for increased fitness and health had long focused on vigorous exercise or the lack thereof. Recently scientific interest in possible effects of sedentary behaviour (SB) (sitting) independent of moderate-vigorous intensity exercise has been growing.We conducted a selective literature search in Pubmed and the Sedentary Research Database with the outcomes SB, risk factors, mortality and morbidity in adults. We included only reviews and systematic reviews.Observational studies suggest an association between SB and all-cause and cardiovascular, but not cancer mortality. SB also seems to be associated with diabetes and overweight/weight gain. Evidence for other diseases, such as cardiovascular diseases, hypertension, cancer, and mental diseases is limited also because of the heterogeneity and poor methodology of the -studies. Intervention studies found inconsistent evidence that SB is associated with detrimental effects on markers of cardiometabolic risk.The evidence on the detrimental effects of sedentary behaviour is decreasingly convincing with the endpoints of mortality, -morbidity, and markers of metabolic risk, in that order. Higher TV and screen time, but not total SB seems to be associated with higher all-cause and cardiovascular, but not cancer mortality. Further intervention studies are needed to establish -dose-response relationships and potentially protective effects of cardiorespiratory fitness and physical activity. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Responding to unprofessional behaviours.

    PubMed

    Worthington, Roger; Hays, Richard

    2012-04-01

    Medical educators sometimes have to respond to inappropriate behaviours from doctors in training that have the potential to endanger their future careers and affect the safety and well-being of their patients. The authors led workshops at international meetings using case-based discussion and plenary wrap-ups to reinforce and share the learning outcomes. This paper summarises key points of difference and common themes about how to manage challenging professional behaviours presented by doctors in training that may be of value to tutors and clinical educators. Although the problems encountered had elements in common, experiences varied between countries, schools and programmes as regards processes, procedures and thresholds for launching an investigation. Whereas variations are not unexpected it is important to consider the context and background against which decisions are made. Appropriate responses must take account of professional, legal and ethical guidelines, where they exist. Major inconsistencies in hearings and investigations may not be in anyone's best interests: fairness is core to most notions of justice, whether from the perspective of a doctor in training, clinical educator or member of the public. Therefore, schools and programmes need to take this into account when reviewing processes and procedures. Although the career of a doctor in training is important, it is not the only consideration. If systems fail the public has a right to be concerned, and striving to ensure that medical students graduate to become safe, professional doctors is something of concern to all clinical educators. © Blackwell Publishing Ltd 2012.

  4. REM sleep Behaviour Disorder.

    PubMed

    Ferini-Strambi, Luigi; Rinaldi, Fabrizio; Giora, Enrico; Marelli, Sara; Galbiati, Andrea

    2016-01-01

    Rapid Eye Movement (REM) sleep Behaviour Disorder (RBD) is a REM sleep parasomnia characterized by loss of the muscle atonia that typically occurs during REM sleep, therefore allowing patients to act out their dreams. RBD manifests itself clinically as a violent behaviour occurring during the night, and is detected at the polysomnography by phasic and/or tonic muscle activity on the electromyography channel. In absence of neurological signs or central nervous system lesions, RBD is defined as idiopathic. Nevertheless, in a large number of cases the development of neurodegenerative diseases in RBD patients has been described, with the duration of the follow-up representing a fundamental aspect. A growing number of clinical, neurophysiologic and neuropsychological studies aimed to detect early markers of neurodegenerative dysfunction in RBD patients. Anyway, the evidence of impaired cortical activity, subtle neurocognitive dysfunction, olfactory and autonomic impairment and neuroimaging brain changes in RBD patients is challenging the concept of an idiopathic form of RBD, supporting the idea of RBD as an early manifestation of a more complex neurodegenerative process.

  5. Driver behaviour at roadworks.

    PubMed

    Walker, Guy; Calvert, Malcolm

    2015-11-01

    There is an incompatibility between how transport engineers think drivers behave in roadworks and how they actually behave. As a result of this incompatibility we are losing approximately a lane's worth of capacity in addition to those closed by the roadworks themselves. The problem would have little significance were it not for the fact a lane of motorway costs approx. £30 m per mile to construct and £43 k a year to maintain, and that many more roadworks are planned as infrastructure constructed 40 or 50 years previously reaches a critical stage in its lifecycle. Given current traffic volumes, and the sensitivity of road networks to congestion, the effects of roadworks need to be accurately assessed. To do this requires a new ergonomic approach. A large-scale observational study of real traffic conditions was used to identify the issues and impacts, which were then mapped to the ergonomic knowledge-base on driver behaviour, and combined to developed practical guidelines to help in modelling future roadworks scenarios with greater behavioural accuracy. Also stemming from the work are novel directions for the future ergonomic design of roadworks themselves.

  6. Alteration of Fractured Rocks Due to Coupled Chemical and Mechanical Processes: High-Resolution Simulations and Experimental Observations

    NASA Astrophysics Data System (ADS)

    Ameli, Pasha

    Engineering activities such as enhanced geothermal energy production and improved oil recovery techniques are heavily dependent on the permeability of the subsurface, while others such as CO2 sequestration and nuclear waste disposal rely on the efficiency of rock formations as transport barriers. In either case fractures provide the main pathways for fluid flow and transport, especially in rocks with lower matrix porosity. Laboratory experiments aimed at quantifying the chemo-mechanical responses of fractures have shown a range of results, some of which contradict simple conceptual models. For example, under conditions favoring mineral dissolution, where one would expect an overall increase in permeability, experiments show that permeability increases under some conditions and decreases under others. Recent experiments have attempted to link these core-scale observations to the relevant small-scale processes occurring within fractures. Results suggest that the loss of mechanical strength in asperities due to chemical alteration may cause non-uniform deformation and alteration of fracture apertures. However, due to the lack of direct micro-scale measurements of the coupled chemical and mechanical processes that lead to alteration of contacting fracture surfaces, our ability to predict the long-term evolution of fractures is still limited. To explore the processes that control permeability evolution, I developed a computational model that uses micro-scale surface roughness and explicitly couples dissolution and elastic deformation to calculate local alterations in fracture aperture under chemical and mechanical stresses. A depth-averaged algorithm of fracture flow is used to model reactive transport and chemical alteration of the fracture surfaces. Then, I deform the resulting altered fracture-surfaces using an algorithm that calculates the elastic deformation. The results of the model are compared with flow-through experiments conducted on fractured limestone. The

  7. Sexual behaviour in young people.

    PubMed

    Gerressu, Makeda; Stephenson, Judith M

    2008-02-01

    The purpose of this review was to synthesize major research findings in relation to young people and sexual behaviour from the period 2006-2007. We found several key reviews that advance knowledge in the field of young people and sexual behaviour, including observational studies, both qualitative and quantitative, and intervention studies designed to reduce sexual transmission of HIV in both developed and developing countries. Other reviews focused on same-sex behaviours, victimization within relationships, HIV infection/sexually transmitted infection in travellers, prevention of HIV/sexually transmitted infection and the determinants of sexual behaviour in young people. Powerful and consistent forces sustain gender differences in sexual behaviour. The design of interventions to reduce sexual risk behaviour should take account of these forces that help explain young people's sexual behaviour. Knowledge about the kind of interventions that reduce risk behaviour and should be implemented has improved, although the impact on health outcomes such as pregnancy and HIV/sexually transmitted infection is often uncertain. Effective school sex education needs to be part of much broader strategies to improve sexual health, and there is an urgent need for better evaluation of interventions, especially community interventions. Further longitudinal studies are needed to provide insight into the development of relationships and sexual behaviour as well as the course of acculturation.

  8. The psychobiology of aggressive behaviour.

    PubMed

    Träskman-Bendz, Lil; Westling, Sofie

    2005-01-01

    Among psychiatric illnesses, genetically determined disorders usually have an early onset and a severe and complicated course. Gene-environmental interaction is of importance for aggressive impulsive behaviour. For example, alcoholism type II has a high family loading, a severe course, and is often associated with antisocial behaviour. In order to gain further understanding of aggressive and impulsive behaviour, genes determining serotonin metabolism, neurosteroids and carbohydrate metabolism should be of interest to investigate. Furthermore, modern brain-imaging studies will reveal the site of action of aggressiveness and impulsivity. Within brain regions of interest, biological studies will promote our knowledge of this deleterious behaviour.

  9. Coupling strength versus coupling impact in nonidentical bidirectionally coupled dynamics

    NASA Astrophysics Data System (ADS)

    Laiou, Petroula; Andrzejak, Ralph G.

    2017-01-01

    The understanding of interacting dynamics is important for the characterization of real-world networks. In general, real-world networks are heterogeneous in the sense that each node of the network is a dynamics with different properties. For coupled nonidentical dynamics symmetric interactions are not straightforwardly defined from the coupling strength values. Thus, a challenging issue is whether we can define a symmetric interaction in this asymmetric setting. To address this problem we introduce the notion of the coupling impact. The coupling impact considers not only the coupling strength but also the energy of the individual dynamics, which is conveyed via the coupling. To illustrate this concept, we follow a data-driven approach by analyzing signals from pairs of coupled model dynamics using two different connectivity measures. We find that the coupling impact, but not the coupling strength, correctly detects a symmetric interaction between pairs of coupled dynamics regardless of their degree of asymmetry. Therefore, this approach allows us to reveal the real impact that one dynamics has on the other and hence to define symmetric interactions in pairs of nonidentical dynamics.

  10. The Association between Bullying Behaviour, Arousal Levels and Behaviour Problems

    ERIC Educational Resources Information Center

    Woods, S.; White, E.

    2005-01-01

    Research into bullying behaviour has identified two main categories of bullying behaviour, direct bullying and relational bullying, within which different profiles are evident, namely 'pure' bullies, 'pure' victims, bully/victims and neutral children. The current study examined the relationship between direct and relational bullying profiles,…

  11. Behavioural and Cognitive-Behavioural Treatments of Parasomnias

    PubMed Central

    Galbiati, Andrea; Rinaldi, Fabrizio; Giora, Enrico; Ferini-Strambi, Luigi; Marelli, Sara

    2015-01-01

    Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development. Nonpharmacological treatments therefore represent valid therapeutic choices. This paper reviews behavioural and cognitive-behavioural managements employed for parasomnias. Referring to the ICSD-3 nosology we consider, respectively, NREM parasomnias, REM parasomnias, and other parasomnias. Although the efficacy of some of these treatments is proved, in other cases their clinical evidence cannot be provided because of the small size of the samples. Due to the rarity of some parasomnias, further multicentric researches are needed in order to offer a more complete account of behavioural and cognitive-behavioural treatments efficacy. PMID:26101458

  12. Behavioural and Cognitive-Behavioural Treatments of Parasomnias.

    PubMed

    Galbiati, Andrea; Rinaldi, Fabrizio; Giora, Enrico; Ferini-Strambi, Luigi; Marelli, Sara

    2015-01-01

    Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development. Nonpharmacological treatments therefore represent valid therapeutic choices. This paper reviews behavioural and cognitive-behavioural managements employed for parasomnias. Referring to the ICSD-3 nosology we consider, respectively, NREM parasomnias, REM parasomnias, and other parasomnias. Although the efficacy of some of these treatments is proved, in other cases their clinical evidence cannot be provided because of the small size of the samples. Due to the rarity of some parasomnias, further multicentric researches are needed in order to offer a more complete account of behavioural and cognitive-behavioural treatments efficacy.

  13. The mechanics of active clays circulated by salts, acids and bases

    NASA Astrophysics Data System (ADS)

    Gajo, Alessandro; Loret, Benjamin

    2007-08-01

    A model that accounts for electro-chemo-mechanical couplings in clays, due to the presence of dissolved salts and acids and bases, is developed and applied to simulate experimental data. Chemically sensitive clays are viewed as two-phase multi-species saturated porous media circulated by an electrolyte. To the authors' best knowledge, no other comprehensive project to embody the effects of pH in the elastic-plastic behavior of geomaterials has been attempted so far. The developments are embedded in the framework of the thermodynamics of multi-phase multi-species porous media. This approach serves to structure the model, and to motivate constitutive equations. The present extension capitalizes upon the earlier developments by Gajo et al. [2002. Electro-chemo-mechanical couplings in saturated porous media: elastic-plastic behaviour of heteroionic expansive clays. Int. J. Solids Struct. 39, 4327-4362] and Gajo and Loret [2004. Transient analysis of ionic replacement in elastic-plastic expansive clays. Int. J. Solids Struct. 41(26), 7493-7531], which were devoted to modeling chemo-mechanical couplings at constant pH. Four transfer mechanisms between the solid and fluid phases are delineated in the model: (1) hydration, (2) ion exchange, (3) acidification, (4) alkalinization. Thus all fundamental exchanges at particle level are fully taken into account. Only mineral dissolution is neglected, since experimental observations indicate a negligible role of mineral dissolution for active clays at room temperature. In particular, the newly considered mechanisms of acidification and alkalinization directly affect the electrical charge of clay particles and thus have a key role in the electro-chemo-mechanical couplings. These four mechanisms are seen as controlling both elastic and elasto-plastic behaviors. Depending on concentrations and ionic affinities to the clay mineral, the transfer mechanisms either compete or cooperate to modify the compressibility and strength of the

  14. Dynamical aspects of coupled Rossler systems: effects of noise

    NASA Astrophysics Data System (ADS)

    Pravitha, R.; Indic, P.; Nampoori, V. P. N.

    2002-02-01

    Nonlinear time series analysis is employed to study the complex behaviour exhibited by a coupled pair of Rossler systems. Dimensional analysis with emphasis on the topological correlation dimension and the Kolmogorov entropy of the system is carried out in the coupling parameter space. The regime of phase synchronization is identified and the extent of synchronization between the systems constituting the coupled system is quantified by the phase synchronization index. The effect of noise on the coupling between the systems is also investigated. An exhaustive study of the topological, dynamical and synchronization properties of the nonlinear system under consideration in its characteristic parameter space is attempted.

  15. The role of son preference in reproductive behaviour in Pakistan.

    PubMed Central

    Hussain, R.; Fikree, F. F.; Berendes, H. W.

    2000-01-01

    The sex of surviving children is an important determinant of reproductive behaviour in South Asia in general and Pakistan in particular. This cohort study evaluates the role of the sex of children on reproductive intentions and subsequent behaviour of women in urban slums of Karachi, Pakistan. The analysis is based on two rounds of surveys conducted in 1990-91 and 1995 of a cohort of married women aged 15-49 years. The results show that pregnancies became increasingly unwanted as the number of surviving sons increased. The sex of surviving children was strongly correlated with subsequent fertility and contraceptive behaviour. However, rather than an exclusive son preference, couples strove for one or more sons and at least one surviving daughter. The policy implications of the link between overt son preference and low status of women are discussed. PMID:10812738

  16. Infant Predictors of Behavioural Inhibition

    ERIC Educational Resources Information Center

    Moehler, Eva; Kagan, Jerome; Oelkers-Ax, Rieke; Brunner, Romuald; Poustka, Luise; Haffner, Johann; Resch, Franz

    2008-01-01

    Behavioural inhibition in the second year of life is a hypothesized predictor for shyness, social anxiety and depression in later childhood, adolescence and even adulthood. To search for the earliest indicators of this fundamental temperamental trait, this study examined whether behavioural characteristics in early infancy can predict behavioural…

  17. Infant Predictors of Behavioural Inhibition

    ERIC Educational Resources Information Center

    Moehler, Eva; Kagan, Jerome; Oelkers-Ax, Rieke; Brunner, Romuald; Poustka, Luise; Haffner, Johann; Resch, Franz

    2008-01-01

    Behavioural inhibition in the second year of life is a hypothesized predictor for shyness, social anxiety and depression in later childhood, adolescence and even adulthood. To search for the earliest indicators of this fundamental temperamental trait, this study examined whether behavioural characteristics in early infancy can predict behavioural…

  18. How coupling determines the entrainment of circadian clocks

    NASA Astrophysics Data System (ADS)

    Bordyugov, G.; Granada, A. E.; Herzel, H.

    2011-08-01

    Autonomous circadian clocks drive daily rhythms in physiology and behaviour. A network of coupled neurons, the suprachiasmatic nucleus (SCN), serves as a robust self-sustained circadian pacemaker. Synchronization of this timer to the environmental light-dark cycle is crucial for an organism's fitness. In a recent theoretical and experimental study it was shown that coupling governs the entrainment range of circadian clocks. We apply the theory of coupled oscillators to analyse how diffusive and mean-field coupling affects the entrainment range of interacting cells. Mean-field coupling leads to amplitude expansion of weak oscillators and, as a result, reduces the entrainment range. We also show that coupling determines the rigidity of the synchronized SCN network, i.e. the relaxation rates upon perturbation. Our simulations and analytical calculations using generic oscillator models help to elucidate how coupling determines the entrainment of the SCN. Our theoretical framework helps to interpret experimental data.

  19. An aetiology of hominin behaviour.

    PubMed

    Bednarik, Robert G

    2012-10-01

    A rough framework for a first attempt to formulate a preliminary aetiology of hominin behaviour is proposed, based on scientific rather than archaeological evidence and reasoning. Distinctive precursors of modernity in human behaviour were present several million years ago, and since then have become gradually more established. By the beginning of the Middle Pleistocene, modern human cognitive processes seem to have been largely established. However, full modernity of behaviour can only have occurred in recent centuries, and there remain great variations in it even among extant conspecifics. This model differs significantly from all narratives offered by mainstream archaeology, which generally place the advent of modern human behaviour 30 or 40 millennia ago. These notions and the hypotheses they are based on appear to be false, however such behaviour is defined. Copyright © 2012 Elsevier GmbH. All rights reserved.

  20. [Forensic psychiatry and behavioural analysis].

    PubMed

    Nitschke, J; Schinke, D; Ottermann, B; Thomas, J; Osterheider, M

    2011-07-01

    A case report shows that a patient could make a progress in his therapy with the help of professional behavioural analysis after a 14-year period of stagnating forensic therapy. The method of behavioural analysis represents a criminalistic tool to reconstruct and to analyse an offence on the basis of objective data. Nowadays this method is also used successfully in individual cases in the field of forensic psychiatry. The article shows and discusses the methodology and the current use of behavioural analysis in forensic psychiatry. professional behavioural analysis of offences of certain forensic patients provides an additional benefit for their therapy and their risk assessment. This kind of approach should be intensified by increasing cooperation with behavioural analysis units and by further training for forensic therapists.

  1. Behavioural biologists don't agree on what constitutes behaviour

    PubMed Central

    Levitis, Daniel A.; Lidicker, William Z.; Freund, Glenn

    2009-01-01

    Behavioural biology is a major discipline within biology, centred on the key concept of `behaviour.' But how is `behaviour' defined, and how should it be defined? We outline what characteristics we believe a scientific definition should have, and why we think it important that a definition have these traits. We then examine the range of available published definitions for the word. Finding no consensus, we present survey responses from 174 members of three behaviour-focused scientific societies as to their understanding of the term. Here again, we find surprisingly widespread disagreement as to what qualifies as behaviour. Respondents contradict themselves, each other, and published definitions, indicating that they are using individually variable intuitive, rather than codified, meanings of `behaviour.' We offer a new definition, based largely on survey responses: “Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.” Finally, we discuss the usage, meanings and limitations of this definition. PMID:20160973

  2. Measuring Thermoforming Behaviour

    NASA Astrophysics Data System (ADS)

    Michaeli, W.; Hopmann, C.; Ederleh, L.; Begemann, M.

    2011-05-01

    Thermoforming is the process of choice for manufacturing thin-gauge or large-area parts for packaging or technical applications. The process allows low-weight parts to be produced rapidly and economically from thermoplastic semi-finished products. A technical and consequently economical problem is the choice of the right material in combination with the thermoformability of the product. The prediction of thermoformability includes the aspired product features and geometry and defined wall thickness distributions, depending on the specific stretchability of the semifinished product. In practice, thermoformability is estimated by empirical tests with the particular semi-finished product using e.g. staged pyramidal moulds or model cars. With this method, it still cannot be ensured that the product can be thermoformed with the intended properties. A promising alternative is the forming simulation using finite element analysis (FEA). For the simulation, it is necessary to describe the material behaviour using defined material models and the appropriate parameters. Therefore, the stress-/strain-behaviour of the semi-finished product under defined conditions is required. There are several, entirely different measurement techniques used in industry and at research facilities. This paper compares a choice of different measurement techniques to provide an objective basis for future work and research. The semi-finished products are examined with the Membrane-Inflation-Rheometer (MIR), an equibiaxial strain rheometer. A flat sample is heated to the desired temperature in silicone oil. During the measurement, a servohydraulic linear drive advances a piston, thus displacing the hot silicone oil and inflating the specimen to form a sphere. Further measurements are carried out with the Karo IV Laboratory Stretching Machine at Brückner Maschinenbau GmbH & Co. KG, Siegsdorf, Germany. The samples are heated using hot air. During the biaxial stretching, the resulting forces at the

  3. Cross-membrane coupling of chemical spatiotemporal patterns

    NASA Astrophysics Data System (ADS)

    Winston, David; Arora, Mukesh; Maselko, Jerzy; Gáspár, Vilmos; Showalter, Kenneth

    1991-05-01

    CHEMICAL systems may communicate by exchange of common species through mass transport, and such coupling may give rise to dynamical complexity beyond that possible in the independent systems1-5. We report here on dynamical behaviour arising from the diffusive coupling of chemical spatiotemporal patterns across a membrane. Chemical waves appear on Nation membranes that are loaded with ferroin catalyst and bathed in a mixture of the reagents of the Belousov-Zhabotinsky oscillatory reaction. The waves on each side of the membrane couple by diffusive transport through the membrane. The coupling initially gives rise to the spontaneous appearance of spiral waves, and subsequent behaviour reveals several distinct phases of evolution, ultimately leading to complete spatiotemporal entrainment.

  4. Quantitative genetic studies of antisocial behaviour.

    PubMed

    Viding, Essi; Larsson, Henrik; Jones, Alice P

    2008-08-12

    This paper will broadly review the currently available twin and adoption data on antisocial behaviour (AB). It is argued that quantitative genetic research can make a significant contribution to further the understanding of how AB develops. Genetically informative study designs are particularly useful for investigating several important questions such as whether: the heritability estimates vary as a function of assessment method or gender; the relative importance of genetic and environmental influences varies for different types of AB; the environmental risk factors are truly environmental; and genetic vulnerability influences susceptibility to environmental risk. While the current data are not yet directly translatable for prevention and treatment programmes, quantitative genetic research has concrete translational potential. Quantitative genetic research can supplement neuroscience research in informing about different subtypes of AB, such as AB coupled with callous-unemotional traits. Quantitative genetic research is also important in advancing the understanding of the mechanisms by which environmental risk operates.

  5. Hormonal mechanisms of cooperative behaviour

    PubMed Central

    Soares, Marta C.; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F.

    2010-01-01

    Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation. PMID:20679116

  6. Developmental constraints on behavioural flexibility

    PubMed Central

    Holekamp, Kay E.; Swanson, Eli M.; Van Meter, Page E.

    2013-01-01

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility. PMID:23569298

  7. Hormonal mechanisms of cooperative behaviour.

    PubMed

    Soares, Marta C; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F

    2010-09-12

    Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation.

  8. Developmental constraints on behavioural flexibility.

    PubMed

    Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

    2013-05-19

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

  9. How can we conceptualize behavioural addiction without pathologizing common behaviours?

    PubMed

    Kardefelt-Winther, Daniel; Heeren, Alexandre; Schimmenti, Adriano; van Rooij, Antonius; Maurage, Pierre; Carras, Michelle; Edman, Johan; Blaszczynski, Alexander; Khazaal, Yasser; Billieux, Joël

    2017-10-01

    Following the recent changes to the diagnostic category for addictive disorders in DSM-5, it is urgent to clarify what constitutes behavioural addiction to have a clear direction for future research and classification. However, in the years following the release of DSM-5, an expanding body of research has increasingly classified engagement in a wide range of common behaviours and leisure activities as possible behavioural addiction. If this expansion does not end, both the relevance and the credibility of the field of addictive disorders might be questioned, which may prompt a dismissive appraisal of the new DSM-5 subcategory for behavioural addiction. We propose an operational definition of behavioural addiction together with a number of exclusion criteria, to avoid pathologizing common behaviours and provide a common ground for further research. The definition and its exclusion criteria are clarified and justified by illustrating how these address a number of theoretical and methodological shortcomings that result from existing conceptualizations. We invite other researchers to extend our definition under an Open Science Foundation framework. © 2017 Society for the Study of Addiction.

  10. Cosmology of bigravity with doubly coupled matter

    SciTech Connect

    Comelli, D.; Crisostomi, M.; Koyama, K.; Pilo, L.; Tasinato, G.

    2015-04-20

    We study cosmology in the bigravity formulation of the dRGT model where matter couples to both metrics. At linear order in perturbation theory two mass scales emerge: an hard one from the dRGT potential, and an environmental dependent one from the coupling of bigravity with matter. At early time, the dynamics is dictated by the second mass scale which is of order of the Hubble scale. The set of gauge invariant perturbations that couples to matter follow closely the same behaviour as in GR. The remaining perturbations show no issue in the scalar sector, while problems arise in the tensor and vector sectors. During radiation domination, a tensor mode grows power-like at super-horizon scales. More dangerously, the only propagating vector mode features an exponential instability on sub-horizon scales. We discuss the consequences of such instabilities and speculate on possible ways to deal with them.

  11. Cosmology of bigravity with doubly coupled matter

    NASA Astrophysics Data System (ADS)

    Comelli, D.; Crisostomi, M.; Koyama, K.; Pilo, L.; Tasinato, G.

    2015-04-01

    We study cosmology in the bigravity formulation of the dRGT model where matter couples to both metrics. At linear order in perturbation theory two mass scales emerge: an hard one from the dRGT potential, and an environmental dependent one from the coupling of bigravity with matter. At early time, the dynamics is dictated by the second mass scale which is of order of the Hubble scale. The set of gauge invariant perturbations that couples to matter follow closely the same behaviour as in GR . The remaining perturbations show no issue in the scalar sector, while problems arise in the tensor and vector sectors. During radiation domination, a tensor mode grows power-like at super-horizon scales. More dangerously, the only propagating vector mode features an exponential instability on sub-horizon scales. We discuss the consequences of such instabilities and speculate on possible ways to deal with them.

  12. Load-cycling technique for R-curve behaviour: Application to a low cement refractory

    NASA Astrophysics Data System (ADS)

    Palmer, G. B.; Baker, G.

    1993-08-01

    The data presented below for a low cement refractory shows that the material has strong R-curve behaviour for certain specimen sizes. The superposition method proposed by Sakai and Bradt was coupled with the effective crack model developed by Karihaloo and Nallathambi and used to investigate this R-curve behaviour. The technique that was developed involves load cycling on one specimen to evaluate K(sub IC) values with crack extension, and was shown to give favorable results for this material.

  13. Couple-centred testing and counselling for HIV serodiscordant heterosexual couples in sub-Saharan Africa.

    PubMed

    Desgrées-du-Loû, Annabel; Orne-Gliemann, Joanna

    2008-11-01

    In Africa, a large proportion of HIV infections occur within stable relationships, either because of prior infection of one of the partners or because of infidelity. In five African countries at least two-thirds of couples with at least one HIV-positive partner were HIV serodiscordant; in half of them, the woman was the HIV-positive partner. Hence, there is an urgent need to define strategies to prevent HIV transmission within couple relationships. HIV counselling and testing have largely been organised on an individual and sex-specific basis, for pregnant women in programmes for prevention of mother-to-child transmission of HIV and in STI consultations and recently male circumcision for men. A couple-centred approach to HIV counselling and testing would facilitate communication about HIV status and adoption of preventive behaviours within couples. This paper reviews what is known about HIV serodiscordance in heterosexual couples in sub-Saharan Africa and what has been published about couple-centred initiatives for HIV counselling and testing since the early 1990s. Despite positive outcomes, couple-oriented programmes have not been implemented on a large scale. In order to stimulate and strengthen HIV prevention efforts, increased attention is required to promote prevention and testing and counselling for couples in stable relationships.

  14. Understanding individual routing behaviour.

    PubMed

    Lima, Antonio; Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C

    2016-03-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. © 2016 The Author(s).

  15. Understanding individual routing behaviour

    PubMed Central

    Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C.

    2016-01-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779–782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65–100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325–362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin–destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. PMID:26962031

  16. The importance of behavioural bioassays in neuroscience.

    PubMed

    Brown, Richard E; Bolivar, Sarah

    2017-05-26

    The behavioural bioassay is fundamental to research in behavioural neuroscience. A described by Tinbergen, behaviour is measured to answer questions about development, mechanisms, adaptation and evolution. Chemical assays, bioassays, and behavioural bioassays have been developed for detecting and quantifying substances such as neurotransmitters, hormones, and toxins and for measuring behaviour. This paper begins with an overview of these methods and then focuses on how behavioural bioassays are developed. Ethograms and qualitative descriptions of behaviour units are discussed. Sampling and recording rules are then considered, along with quantitative descriptions of the behaviours being observed. The paper concludes with examples of behavioural bioassays used for detecting various internal and external stimuli, along with considerations such as the complexity of the stimuli and the problem of measuring "psychological" states such as anxiety, from behaviour. Suggestions are made for improving the validity and reliability of behavioural bioassays in neuroscience. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Where is behavioural ecology going?

    PubMed

    Owens, Ian P F

    2006-07-01

    Since the 1990s, behavioural ecologists have largely abandoned some traditional areas of interest, such as optimal foraging, but many long-standing challenges remain. Moreover, the core strengths of behavioural ecology, including the use of simple adaptive models to investigate complex biological phenomena, have now been applied to new puzzles outside behaviour. But this strategy comes at a cost. Replication across studies is rare and there have been few tests of the underlying genetic assumptions of adaptive models. Here, I attempt to identify the key outstanding questions in behavioural ecology and suggest that researchers must make greater use of model organisms and evolutionary genetics in order to make substantial progress on these topics.

  18. [Professional behaviour during medical training].

    PubMed

    van Mook, Walther N K A; van Luijk, Scheltus J; van der Vleuten, Cees P M

    2009-01-01

    Assessment of professional behaviour (PB) is increasingly receiving attention in undergraduate and postgraduate medical training. Its aim is to prevent later inappropriate behaviour and to strengthen appropriate behaviour by self-reflection and feedback. Assessment should start early in the curriculum and be repeated frequently, preferably by different assessors in differing educational situations, and with longitudinal follow-up. The consequences of the assessment as well as any agreements reached, must be clearly documented. If remediation of inappropriate behaviour is unsuccessful, a consilium abeundi, i.e. a recommendation to leave the programme, should be discussed with the student. The Dutch Higher Education and Scientific Research Act (WHW) does not provide for denying students access to educational activities and exams after completing the first year. However, the new Higher Education and Research Act (WHOO), which has yet not been implemented, will provide for obligatory cessation of studies.

  19. Collective behaviour across animal species.

    PubMed

    DeLellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M; Porfiri, Maurizio

    2014-01-16

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  20. Collective behaviour across animal species

    NASA Astrophysics Data System (ADS)

    Delellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M.; Porfiri, Maurizio

    2014-01-01

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  1. An investigation of the in-game behaviours of professional, top-level youth soccer coaches.

    PubMed

    Smith, Matt; Cushion, Christopher J

    2006-04-01

    Although research into coaching has increased considerably during the last two decades, an area of neglect has been that of the professional youth coach. The aim of this study was to investigate the working behaviours of six top-level professional soccer coaches. Data were collected using a modified version of the Arizona State University Observation Instrument and semi-structured interviews. The triangulation of the data ensured that both the "what" and the "why" of the coaches' behaviour were considered. Results revealed a conscious and well thought out pattern of behaviour: silently monitoring, interspersed with clips of instruction coupled with praise and encouragement. The interviews revealed three themes underpinning this behaviour: developing game understanding, support and encouragement, and coaches' role and influences. The use of silence was the largest single behaviour, the efficacy of which was considered in light of theories of experiential and discovery learning.

  2. Affecting non-Markovian behaviour by changing bath structures

    NASA Astrophysics Data System (ADS)

    Venkataraman, V.; Plato, A. D. K.; Tufarelli, Tommaso; Kim, M. S.

    2014-01-01

    For many open quantum systems, a master equation approach employing the Markov approximation cannot reliably describe the dynamical behaviour. This is the case, for example, in a number of solid state or biological systems, and it has motivated a line of research aimed at quantifying the amount of non-Markovian behaviour (NMB) in a given model. Within this framework, we investigate the dynamics of a quantum harmonic oscillator linearly coupled to a bosonic bath. We focus on Gaussian states, which are suitably treated using a covariance matrix approach. Concentrating on an entanglement based NMB quantifier (NMBQ) proposed by Rivas et al (2010 Phys. Rev. Lett. 105 050403), we consider the role that near resonant and off-resonant modes play in affecting the NMBQ. By using a large but finite bath of oscillators for both Ohmic and super Ohmic spectral densities we find, by systematically increasing the coupling strength, initially the near resonant modes provide the most significant non-Markovian effects, while after a certain threshold of coupling strength the off-resonant modes play the dominant role. We also consider the NMBQ for two other models where we add a single strongly coupled oscillator to the model in extra bath mode and ‘buffer’ configurations, which affects the modes that determine NMB.

  3. The Problem Behaviour Checklist: short scale to assess challenging behaviours

    PubMed Central

    Nagar, Jessica; Evans, Rosie; Oliver, Patricia; Bassett, Paul; Liedtka, Natalie; Tarabi, Aris

    2016-01-01

    Background Challenging behaviour, especially in intellectual disability, covers a wide range that is in need of further evaluation. Aims To develop a short but comprehensive instrument for all aspects of challenging behaviour. Method In the first part of a two-stage enquiry, a 28-item scale was constructed to examine the components of challenging behaviour. Following a simple factor analysis this was developed further to create a new short scale, the Problem Behaviour Checklist (PBCL). The scale was subsequently used in a randomised controlled trial and tested for interrater reliability. Scores were also compared with a standard scale, the Modified Overt Aggression Scale (MOAS). Results Seven identified factors – personal violence, violence against property, self-harm, sexually inappropriate, contrary, demanding and disappearing behaviour – were scored on a 5-point scale. A subsequent factor analysis with the second population showed demanding, violent and contrary behaviour to account for most of the variance. Interrater reliability using weighted kappa showed good agreement (0.91; 95% CI 0.83–0.99). Good agreement was also shown with scores on the MOAS and a score of 1 on the PBCL showed high sensitivity (97%) and specificity (85%) for a threshold MOASscore of 4. Conclusions The PBCL appears to be a suitable and practical scale for assessing all aspects of challenging behaviour. Declaration of interest None. Copyright and usage © 2016 The Royal College of Psychiatrists. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. PMID:27703753

  4. 4 Hz oscillations synchronize prefrontal-amygdala circuits during fear behaviour

    PubMed Central

    Karalis, Nikolaos; Dejean, Cyril; Chaudun, Fabrice; Khoder, Suzana; Rozeske, Robert R.; Wurtz, Hélène; Bagur, Sophie; Benchenane, Karim; Sirota, Anton; Courtin, Julien; Herry, Cyril

    2016-01-01

    Fear expression relies on the coordinated activity of prefrontal and amygdala circuits, yet the mechanisms allowing long-range network synchronization during fear remain unknown. Using a combination of extracellular recordings, pharmacological, and optogenetic manipulations we report that freezing, a behavioural expression of fear, temporally coincides with the development of sustained, internally generated 4 Hz oscillations within prefrontal-amygdala circuits. 4 Hz oscillations predict freezing onset and offset and synchronize prefrontal-amygdala circuits. Optogenetic induction of prefrontal 4 Hz oscillations coordinates prefrontal-amygdala activity and elicits fear behaviour. These results unravel a novel sustained oscillatory mechanism mediating prefrontal-amygdala coupling during fear behaviour. PMID:26878674

  5. Microseconds, milliseconds and seconds: deconvoluting the dynamic behaviour of planar perovskite solar cells.

    PubMed

    Pockett, Adam; Eperon, Giles E; Sakai, Nobuya; Snaith, Henry J; Peter, Laurence M; Cameron, Petra J

    2017-02-22

    Perovskite solar cells (PSC) are shown to behave as coupled ionic-electronic conductors with strong evidence that the ionic environment moderates both the rate of electron-hole recombination and the band offsets in planar PSC. Numerous models have been presented to explain the behaviour of perovskite solar cells, but to date no single model has emerged that can explain both the frequency and time dependent response of the devices. Here we present a straightforward coupled ionic-electronic model that can be used to explain the large amplitude transient behaviour and the impedance response of PSC.

  6. Perceived social support and parental education as determinants of adolescents' physical activity and eating behaviour: a cross-sectional survey.

    PubMed

    Glozah, Franklin N; Pevalin, David J

    2015-08-01

    To examine the role of perceived social support and parental education on physical activity and eating behaviour of Ghanaian adolescents. Seven hundred and seventy Senior High School students (504 boys and 266 girls) between the ages of 14-21 years participated by completing questionnaires on perceived social support, physical activity and eating behaviour. The highest education attained by either parent or guardian was also obtained. Multivariate analysis of covariance was the main statistical test used to analyse the data. The results showed significant gender differences in physical activity and eating behaviour combined, with boys more likely to engage in physical activity than girls, and girls also more likely to engage in healthy eating behaviour than boys, albeit the effect was not statistically significant. While perceived social support had a significant positive effect on eating behaviour and physical activity, parental education had a significant effect only on eating behaviour but not physical activity. Perceived social support from family coupled with parental education provides more opportunities for adolescents to engage in healthy eating behaviour. Also, parents' educational attainment alone does not necessarily guarantee that adolescents will engage in physical activity; providing the needed social support and conducive home environment is more likely to induce physical activity behaviours. Finally, physical activity and eating behaviour should not be construed as alternative health behaviours as suggested by gender differentials in these health behaviours.

  7. Neural mechanisms underlying the evolvability of behaviour

    PubMed Central

    Katz, Paul S.

    2011-01-01

    The complexity of nervous systems alters the evolvability of behaviour. Complex nervous systems are phylogenetically constrained; nevertheless particular species-specific behaviours have repeatedly evolved, suggesting a predisposition towards those behaviours. Independently evolved behaviours in animals that share a common neural architecture are generally produced by homologous neural structures, homologous neural pathways and even in the case of some invertebrates, homologous identified neurons. Such parallel evolution has been documented in the chromatic sensitivity of visual systems, motor behaviours and complex social behaviours such as pair-bonding. The appearance of homoplasious behaviours produced by homologous neural substrates suggests that there might be features of these nervous systems that favoured the repeated evolution of particular behaviours. Neuromodulation may be one such feature because it allows anatomically defined neural circuitry to be re-purposed. The developmental, genetic and physiological mechanisms that contribute to nervous system complexity may also bias the evolution of behaviour, thereby affecting the evolvability of species-specific behaviour. PMID:21690127

  8. Neural mechanisms underlying the evolvability of behaviour.

    PubMed

    Katz, Paul S

    2011-07-27

    The complexity of nervous systems alters the evolvability of behaviour. Complex nervous systems are phylogenetically constrained; nevertheless particular species-specific behaviours have repeatedly evolved, suggesting a predisposition towards those behaviours. Independently evolved behaviours in animals that share a common neural architecture are generally produced by homologous neural structures, homologous neural pathways and even in the case of some invertebrates, homologous identified neurons. Such parallel evolution has been documented in the chromatic sensitivity of visual systems, motor behaviours and complex social behaviours such as pair-bonding. The appearance of homoplasious behaviours produced by homologous neural substrates suggests that there might be features of these nervous systems that favoured the repeated evolution of particular behaviours. Neuromodulation may be one such feature because it allows anatomically defined neural circuitry to be re-purposed. The developmental, genetic and physiological mechanisms that contribute to nervous system complexity may also bias the evolution of behaviour, thereby affecting the evolvability of species-specific behaviour.

  9. Users of withdrawal method in the Islamic Republic of Iran: are they intending to use oral contraceptives? Applying the theory of planned behaviour.

    PubMed

    Rahnama, P; Hidarnia, A; Shokravi, F A; Kazemnejad, A; Montazeri, A; Najorkolaei, F R; Saburi, A

    2013-09-01

    Many couples in the Islamic Republic of Iran rely on coital withdrawal for contraception. The purpose of this cross-sectional study was to use the theory of planned behaviour to explore factors that influence withdrawal users' intent to switch to oral contraception (OC). Participants were 336 sexually active, married women, who were current users of withdrawal and were recruited from 5 public family planning clinics in Tehran. A questionnair included measures of the theory of planned behaviour: attitude (behavioural beliefs, outcome evaluations), subjective norms (normative beliefs, motivation to comply), perceived behaviour control, past behaviour and behavioural intention. Linear regression analyses showed that past behaviour, perceived behaviour control, attitude and subjective norms accounted for the highest percentage of total variance observed for intention to use OC (36%). Beliefs-based family planning education and counsellingshould to be designed for users of the withdrawal method.

  10. Couple communication in stepfamilies.

    PubMed

    Halford, Kim; Nicholson, Jan; Sanders, Matthew

    2007-12-01

    Effective communication is assumed to help sustain couple relationships and is a key focus of most relationship education programs. We assessed couple problem-solving communication in 65 stepfamily and 52 first-time-marrying couples, with each group stratified into high risk and low risk for relationship problems based on family-of-origin experiences. Relative to partners in first-time couples, partners in stepfamily couples were less positive, less negative, and more likely to withdraw from discussion. Risk was associated with communication in first-time but not stepfamily couples. Stepfamily couples do not exhibit the negative communication evident in high-risk first-time-marrying couples, and available relationship education programs that focus on reducing negative communication are unlikely to meet the needs of stepfamilies.

  11. Media-based behavioural treatments for behavioural problems in children.

    PubMed

    Montgomery, P; Bjornstad, G; Dennis, J

    2006-01-25

    Many approaches are used to address behavioural problems in childhood including medication or, more usually, psychological treatments either directly with the child and/or his/her family. Behavioural and cognitive-behavioural interventions have been shown to be highly effective but access to these treatments is limited due to factors such as time and expense. Presenting the information parents need in order to manage these behaviour problems in booklet or other media-based format would most likely reduce the cost and increase access to these interventions. To review the effects of media-based cognitive-behavioural therapies for any young person with a behavioural disorder (diagnosed using a recognised instrument) compared to standard care and no-treatment controls. The following electronic databases were systematically searched: CENTRAL (The Cochrane Library Issue 3, 2005), MEDLINE (1966 to August 2005), EMBASE (1980 to August 2005), PsycINFO (1887 to August 2005), CINAHL (1982 to August 2005), Biosis (1985 to August 2005) and Sociofile (1974 to August 2005). References in all selected trials were checked for other trials and experts in the field were contacted for additional information. Randomised and quasi-randomised controlled trials (e.g. trials which used sequential randomisation) of media-based behavioural treatments for behaviour problems in children. Abstracts and titles of studies identified from searches of electronic databases were read to determine whether they met the inclusion criteria. Full copies of those possibly meeting these criteria from electronic or other searches were assessed by the reviewers and queries were resolved by discussion. Data were analysed using RevMan 4.2. Eleven studies including 943 participants were included within this review. In general, media-based therapies for behavioural disorders in children had a moderate, if variable, effect when compared with both no-treatment controls with effects sizes ranging from -0.12 (-1

  12. Best behaviour? Ontologies and the formal description of animal behaviour.

    PubMed

    Gkoutos, Georgios V; Hoehndorf, Robert; Tsaprouni, Loukia; Schofield, Paul N

    2015-10-01

    The development of ontologies for describing animal behaviour has proved to be one of the most difficult of all scientific knowledge domains. Ranging from neurological processes to human emotions, the range and scope needed for such ontologies is highly challenging, but if data integration and computational tools such as automated reasoning are to be fully applied in this important area the underlying principles of these ontologies need to be better established and development needs detailed coordination. Whilst the state of scientific knowledge is always paramount in ontology and formal description framework design, this is a particular problem with neurobehavioural ontologies where our understanding of the relationship between behaviour and its underlying biophysical basis is currently in its infancy. In this commentary, we discuss some of the fundamental problems in designing and using behaviour ontologies, and present some of the best developed tools in this domain.

  13. Simulations of Edge Effect in 1D Spin Crossover Compounds by Atom-Phonon Coupling Model

    NASA Astrophysics Data System (ADS)

    Linares, J.; Chiruta, D.; Jureschi, C. M.; Alayli, Y.; Turcu, C. O.; Dahoo, P. R.

    2016-08-01

    We used the atom-phonon coupling model to explain and illustrate the behaviour of a linear nano-chain of molecules. The analysis of the system's behaviour was performed using Free Energy method, and by applying Monte Carlo Metropolis (MCM) method which take into account the phonon contribution. In particular we tested both the MCM algorithm and the dynamic-matrix method and we expose how the thermal behaviour of a 1D spin crossover system varies as a function of different factors. Furthermore we blocked the edge atoms of the chain in its high spin state to study the effect on the system's behaviour.

  14. Time-delayed conjugate coupling in dynamical systems

    NASA Astrophysics Data System (ADS)

    Sharma, Amit; Shrimali, Manish Dev; Prasad, Awadhesh; Ramaswamy, Ram

    2017-06-01

    We study the effect of time-delay when the coupling between nonlinear systems is "conjugate", namely through dissimilar variables. This form of coupling can induce anomalous transitions such as the emergence of oscillatory dynamics between regimes of amplitude death and oscillation death. The specific cases of coupled Landau-Stuart oscillators as well as a predator-prey model system with cross-predation are discussed. The dynamical behaviour is analyzed numerically and the regions corresponding to different asymptotic states are identified in parameter space.

  15. Reward, context, and human behaviour.

    PubMed

    Blaukopf, Clare L; DiGirolamo, Gregory J

    2007-05-29

    Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman) knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.

  16. Habit versus planned behaviour: a field experiment.

    PubMed

    Verplanken, B; Aarts, H; van Knippenberg, A; Moonen, A

    1998-03-01

    A field experiment investigated the prediction and change in repeated behaviour in the domain of travel mode choices. Car use during seven days was predicted from habit strength (measured by self-reported frequency of past behaviour, as well as by a more covert measure based on personal scripts incorporating the behaviour), and antecedents of behaviour as conceptualized in the theory of planned behaviour (attitude, subjective norm, perceived behavioural control and behavioural intention). Both habit measures predicted behaviour in addition to intention and perceived control. Significant habit x intention interactions indicated that intentions were only significantly related to behaviour when habit was weak, whereas no intention-behaviour relation existed when habit was strong. During the seven-day registration of behaviour, half of the respondents were asked to think about the circumstances under which the behaviour was executed. Compared to control participants, the behaviour of experimental participants was more strongly related to their previously expressed intentions. However, the habit-behaviour relation was unaffected. The results demonstrate that, although external incentives may increase the enactment of intentions, habits set boundary conditions for the applicability of the theory of planned behaviour.

  17. The physiological cost of velocity coupling during tennis groundstrokes.

    PubMed

    Cooke, Karl; Davey, Polly R

    2007-05-01

    Velocity coupling denotes a perceptual motor behaviour known to occur during coincidence timing tasks. Individuals have been shown to increase their effector limb speed with increases in stimulus speed during interceptive tasks. However, little is known about the physiological effects of velocity coupling. The aim of this study was to determine the physiological cost of velocity coupling during tennis groundstrokes. Eight male and eight female competitive tennis players volunteered to perform three 4-min bouts of continuous groundstrokes against balls projected from a tennis ball machine at speeds of 18, 22, and 27 m x s(-1) (65, 79, and 97 km x h(-1)) and a frequency of 14 balls per minute, the order of which was counterbalanced. Breath-by-breath pulmonary gas exchange, heart rate, locomotion time, and limb acceleration were measured throughout each of the 4-min bouts. Capillary blood samples (for blood lactate analysis), rating of perceived exertion, and difficulty rating were taken at the end of each bout. Increasing ball speed did not influence the locomotion time between groundstrokes but did result in a bilateral increase in both the mean upper- and lower-limb acceleration (all P < 0.05). Velocity coupling behaviour increased oxygen uptake, blood lactate concentration, heart rate, rating of perceived exertion, and perceived task difficulty (all P < 0.05). It would appear, therefore, that velocity coupling influenced tennis groundstroke behaviour and indirectly modified the concurrent cardiopulmonary and metabolic responses.

  18. Anomalous basal ganglia connectivity and obsessive–compulsive behaviour in patients with Prader Willi syndrome

    PubMed Central

    Pujol, Jesus; Blanco-Hinojo, Laura; Esteba-Castillo, Susanna; Caixàs, Assumpta; Harrison, Ben J.; Bueno, Marta; Deus, Joan; Rigla, Mercedes; Macià, Dídac; Llorente-Onaindia, Jone; Novell-Alsina, Ramón

    2016-01-01

    Background Prader Willi syndrome is a genetic disorder with a behavioural expression characterized by the presence of obsessive–compulsive phenomena ranging from elaborate obsessive eating behaviour to repetitive skin picking. Obsessive–compulsive disorder (OCD) has been recently associated with abnormal functional coupling between the frontal cortex and basal ganglia. We have tested the potential association of functional connectivity anomalies in basal ganglia circuits with obsessive–compulsive behaviour in patients with Prader Willi syndrome. Methods We analyzed resting-state functional MRI in adult patients and healthy controls. Whole-brain functional connectivity maps were generated for the dorsal and ventral aspects of the caudate nucleus and putamen. A selected obsessive–compulsive behaviour assessment included typical OCD compulsions, self picking and obsessive eating behaviour. Results We included 24 adults with Prader Willi syndrome and 29 controls in our study. Patients with Prader Willi syndrome showed abnormal functional connectivity between the prefrontal cortex and basal ganglia and within subcortical structures that correlated with the presence and severity of obsessive–compulsive behaviours. In addition, abnormally heightened functional connectivity was identified in the primary sensorimotor cortex–putamen loop, which was strongly associated with self picking. Finally, obsessive eating behaviour correlated with abnormal functional connectivity both within the basal ganglia loops and between the striatum and the hypothalamus and the amygdala. Limitations Limitations of the study include the difficulty in evaluating the nature of content of obsessions in patients with Prader Willi Syndrome and the risk of excessive head motion artifact on brain imaging. Conclusion Patients with Prader Willi syndrome showed broad functional connectivity anomalies combining prefrontal loop alterations characteristic of OCD with 1) enhanced coupling in the

  19. Moderators of the intention-behaviour and perceived behavioural control-behaviour relationships for leisure-time physical activity

    PubMed Central

    Amireault, Steve; Godin, Gaston; Vohl, Marie-Claude; Pérusse, Louis

    2008-01-01

    Background Intention is a key determinant of action. However, there is a gap between intention and behavioural performance that remains to be explained. Therefore, the aim of this study was to identify moderators of the intention-behaviour and perceived behavioural control (PBC)- behaviour relationships for leisure-time physical activity. Method This was tested in reference to Ajzen's Theory of Planned Behaviour. A sample of 300 volunteers, 192 women and 108 men, aged 18 to 55, participated in the study. At baseline, the participants completed a self-administrated psychosocial questionnaire assessing Ajzen's theory variables (i.e., intention and perceived behavioural control). The behavioural measure was obtained by mail three months later. Results Multiple hierarchical regression analyses indicated that age and annual income moderated the intention-behaviour and PBC-behaviour relationships. However, in the final model predicting behaviour (R2 = .46), only the interaction term of PBC by annual income (β = .24, p = 0.0003) significantly contributed to the prediction of behaviour along with intention (β = .49, p = 0.0009) and past behaviour (β = .44, p < 0.0001). Conclusion Physical activity promotion programs would benefit not only from focusing on increasing the intention of low intenders, but also from targeting factors that moderate the perceived behavioural control-behaviour relationships. PMID:18241339

  20. Adolescent binge drinking and risky health behaviours: findings from northern Russia.

    PubMed

    Stickley, Andrew; Koyanagi, Ai; Koposov, Roman; Razvodovsky, Yury; Ruchkin, Vladislav

    2013-12-15

    Some evidence suggests that in recent years the prevalence of heavy drinking has increased among Russian adolescents. However, as yet, little is known about either heavy alcohol consumption or its relationship with other adolescent health risk behaviours in Russia. The aim of this study therefore was to investigate the association between binge drinking and health risk behaviours among adolescents in Russia. Data were drawn from the Social and Health Assessment (SAHA), a survey carried out in Arkhangelsk, Russia in 2003. Information was obtained from a representative sample of 2868 adolescents aged 13-17 regarding the prevalence and frequency of binge drinking (five or more drinks in a row in a couple of hours) and different forms of substance use, risky sexual behaviour and violent behaviour. Logistic regression analysis was used to examine the association between binge drinking and adolescent involvement in various health risk behaviours. Adolescent binge drinking was associated with the occurrence of every type of health risk behaviour - with the sole exception of non-condom use during last sex. In addition, there was a strong association between the number of days on which binge drinking occurred and the prevalence of many health risk behaviours. Binge drinking is associated with a variety of health risk behaviours among adolescents in Russia. Public health interventions such as reducing the affordability and accessibility of alcohol are now needed to reduce binge drinking and its harmful effects on adolescent well-being. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Flossing behaviour in English adolescents.

    PubMed

    Macgregor, I D; Balding, J W; Regis, D

    1998-04-01

    The aim of this study was to investigate the relation between flossing behaviour and other health, cleanliness and social behaviours in adolescents. Data from a survey of 41142, 12-16-year-old children from 244 secondary schools throughout England were analysed to obtain information about flossing frequency, dental attendance and recalled advice about flossing, and some general cleanliness and social behaviours. Subjects completed a questionnaire, anonymously, in class during normal school hours. Flossing frequency was found to change with age, its use becoming less frequent from age 12 through age 16 years. There was a significant relationship between flossing frequency and the time since the last dental attendance, the more recent attenders flossing more frequently. 6% of subjects recalled receiving advice about flossing at their last dental attendance and higher proportions of those who used floss recalled such advice, compared with non-flossers. Flossing frequency was also found to correlate positively with frequencies of washing hands after visiting the lavatory and bathing, and having a current friend of the opposite gender. There was only a small association between smoking habit and flossing, and only in school years 8 and 10: subjects most committed to smoking used floss slightly more frequently than those who did not smoke. Factor analysis showed evidence of gender differences in perceptions of flossing. Males equated use of floss with health-related behaviours while females associated flossing more with cleanliness behaviours. This finding is consistent with gender differences in toothbrushing behaviour reported in previous studies. The present study provides further insights into the history of dental flossing.

  2. Collective behaviour across animal species

    PubMed Central

    DeLellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M.; Porfiri, Maurizio

    2014-01-01

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment. PMID:24430561

  3. Hygienic food handling behaviours. An application of the Theory of Planned Behaviour.

    PubMed

    Mullan, Barbara A; Wong, Cara L

    2009-06-01

    It is estimated that 5.4 million Australians get sick annually from eating contaminated food and that up to 20% of this illness results from food handling behaviour. A study was undertaken to investigate the efficacy of the Theory of Planned Behaviour (TPB) including past behaviour in predicting safe food handling intention and behaviour. One hundred and nine participants completed questionnaires regarding their attitudes, perceived behavioural control (PBC), subjective norm, intentions and past behaviour. Behaviour was measured 4 weeks later. The TPB predicted a high proportion of variance in both intentions and behaviour, and past behaviour/habit was found to be the strongest predictor of behaviour. The results of the present study suggest interventions aimed at increasing safe food handling intentions should focus on the impact of normative influences and perceptions of control over their food handling environment; whereas interventions to change actual behaviour should attempt to increase hygienic food handling as a habitual behaviour.

  4. Theories of behaviour and behaviour change across the social and behavioural sciences: a scoping review.

    PubMed

    Davis, Rachel; Campbell, Rona; Hildon, Zoe; Hobbs, Lorna; Michie, Susan

    2015-01-01

    Interventions to change health-related behaviours typically have modest effects and may be more effective if grounded in appropriate theory. Most theories applied to public health interventions tend to emphasise individual capabilities and motivation, with limited reference to context and social factors. Intervention effectiveness may be increased by drawing on a wider range of theories incorporating social, cultural and economic factors that influence behaviour. The primary aim of this paper is to identify theories of behaviour and behaviour change of potential relevance to public health interventions across four scientific disciplines: psychology, sociology, anthropology and economics. We report in detail the methodology of our scoping review used to identify these theories including which involved a systematic search of electronic databases, consultation with a multidisciplinary advisory group, web searching, searching of reference lists and hand searching of key behavioural science journals. Of secondary interest we developed a list of agreed criteria for judging the quality of the theories. We identified 82 theories and 9 criteria for assessing theory quality. The potential relevance of this wide-ranging number of theories to public health interventions and the ease and usefulness of evaluating the theories in terms of the quality criteria are however yet to be determined.

  5. Theories of behaviour and behaviour change across the social and behavioural sciences: a scoping review

    PubMed Central

    Davis, Rachel; Campbell, Rona; Hildon, Zoe; Hobbs, Lorna; Michie, Susan

    2015-01-01

    Interventions to change health-related behaviours typically have modest effects and may be more effective if grounded in appropriate theory. Most theories applied to public health interventions tend to emphasise individual capabilities and motivation, with limited reference to context and social factors. Intervention effectiveness may be increased by drawing on a wider range of theories incorporating social, cultural and economic factors that influence behaviour. The primary aim of this paper is to identify theories of behaviour and behaviour change of potential relevance to public health interventions across four scientific disciplines: psychology, sociology, anthropology and economics. We report in detail the methodology of our scoping review used to identify these theories including which involved a systematic search of electronic databases, consultation with a multidisciplinary advisory group, web searching, searching of reference lists and hand searching of key behavioural science journals. Of secondary interest we developed a list of agreed criteria for judging the quality of the theories. We identified 82 theories and 9 criteria for assessing theory quality. The potential relevance of this wide-ranging number of theories to public health interventions and the ease and usefulness of evaluating the theories in terms of the quality criteria are however yet to be determined. PMID:25104107

  6. Behavioural Precursors and HIV Testing Behaviour among African American Women

    ERIC Educational Resources Information Center

    Uhrig, Jennifer D.; Davis, Kevin C.; Rupert, Doug; Fraze, Jami

    2012-01-01

    Objective: To examine whether there is an association between knowledge, attitudes and beliefs, reported intentions to get an HIV test, and reported HIV testing behaviour at a later date among a sample of African American women. Design: Secondary analysis of data collected from October 2007 through March 2008 for a randomized controlled experiment…

  7. Better Behaviour. Building Success through Better Behaviour Series

    ERIC Educational Resources Information Center

    Long, Rob

    2005-01-01

    Many children have all sorts of difficulties in their lives, which set up barriers to learning. This book demonstrates how teachers can help them face personal challenges. It contains: ideas for stress proofing children; guidance on teaching problem-solving skills; and explanations of cognitive behaviour therapy.

  8. Behavioural Precursors and HIV Testing Behaviour among African American Women

    ERIC Educational Resources Information Center

    Uhrig, Jennifer D.; Davis, Kevin C.; Rupert, Doug; Fraze, Jami

    2012-01-01

    Objective: To examine whether there is an association between knowledge, attitudes and beliefs, reported intentions to get an HIV test, and reported HIV testing behaviour at a later date among a sample of African American women. Design: Secondary analysis of data collected from October 2007 through March 2008 for a randomized controlled experiment…

  9. Dissociation between affective experience and motivated behaviour in schizophrenia patients and their unaffected first-degree relatives and schizotypal individuals.

    PubMed

    Xie, Dong-Jie; Lui, Simon S Y; Geng, Fu-Lei; Yang, Zhuo-Ya; Zou, Ying-Min; Li, Ying; Yeung, Hera K H; Cheung, Eric F C; Heerey, Erin A; Chan, Raymond C K

    2017-10-11

    The neuropsychological origins of negative syndrome of schizophrenia remain elusive. Evidence from behavioural studies, which utilised emotion-inducing pictures to elicit motivated behaviour generally reported that that schizophrenia patients experienced similar affective experience as healthy individuals but failed to translate emotional salience to motivated behaviour, a phenomenon called emotion-behaviour decoupling. However, a few studies have examined emotion-behaviour decoupling in non-psychotic high-risk populations, who are relatively unaffected by medication effects. In this study, we examined the nature and extent of emotion-behaviour decoupling in in three independent samples (65 schizophrenia patients v. 63 controls; 40 unaffected relatives v. 45 controls; and 32 individuals with social anhedonia v. 32 controls). We administered an experimental task to examine their affective experience and its coupling with behaviour, using emotion-inducing slides, and allowed participants to alter stimulus exposure using button-pressing to seek pleasure or avoid aversion. Schizophrenia patients reported similar affective experiences as their controls, while their unaffected relatives and individuals with high levels of social anhedonia exhibited attenuated affective experiences, in particular in the arousal aspect. Compared with their respective control groups, all of the three groups showed emotion-behaviour decoupling. Our findings support that both genetically and behaviourally high-risk groups exhibit emotion-behaviour decoupling. The familial association apparently supports its role as a putative trait marker for schizophrenia.

  10. Challenging Behaviours: Prevalence and Topographies

    ERIC Educational Resources Information Center

    Lowe, K.; Allen, D.; Jones, E.; Brophy, S.; Moore, K.; James, W.

    2007-01-01

    Background: Variations in reported prevalence of challenging behaviour indicate the need for further epidemiological research to support accurate planning of future service provision. Methods: All services providing for people with learning disabilities across seven unitary authorities, with a total population of 1.2 million, were screened to…

  11. Confusion and altered behaviour? Cause

    PubMed Central

    Lobo, Ronstan; Pillay, Isweri; Kennedy, Barry; Watts, Michael

    2013-01-01

    We describe the case of a 65-year-old man who presented with confusion and change in behaviour, and describe the investigative steps that were taken before a diagnosis was made. This patient was eventually diagnosed with leptomeningeal carcinomatosis secondary to a previously undiagnosed oesophageal carcinoma. PMID:23341584

  12. Handbook of Emotional & Behavioural Difficulties

    ERIC Educational Resources Information Center

    Clough, Peter; Garner, Philip; Pardeck, John T.; Yuen, Francis K.O.

    2005-01-01

    The behaviour of children in primary/elementary and secondary/high schools has been a consistent source of interest and controversy since the 19th century. As education systems in First World democracies struggle to meet changing social, economic and educational conditions, one group of children has increasingly become the focus of attention.…

  13. Behaviour: Seeing heat saves energy

    NASA Astrophysics Data System (ADS)

    Steg, Linda

    2016-01-01

    Household energy conservation can help to significantly lower energy consumption. Visual cues provided by thermal imaging of heat loss in buildings are now shown to increase energy conserving behaviours and implementations among homeowners more effectively than just performing carbon footprint audits.

  14. Boundaries in Visualizing Mathematical Behaviour

    ERIC Educational Resources Information Center

    Hare, Andrew Francis

    2013-01-01

    It is surprising to students to learn that a natural combination of simple functions, the function sin(1/x), exhibits behaviour that is a great challenge to visualize. When x is large the function is relatively easy to draw; as x gets smaller the function begins to behave in an increasingly wild manner. The sin(1/x) function can serve as one of…

  15. Characterisation of chocolate eating behaviour.

    PubMed

    Carvalho-da-Silva, A M; Van Damme, I; Wolf, B; Hort, J

    2011-10-24

    Knowledge concerning variation in chocolate eating behaviour amongst consumers, and the impact that differences in the physical properties of chocolate could have on such behaviour is limited. The eating behaviour of individuals, consuming two chocolate samples (A and B), of comparable melt viscosity but with different textural attributes, was investigated. Surface electromyography (sEMG) was used to evaluate masticator muscle activity and electroglottography (EGG) was used to record swallowing events. Results showed that observed differences in mouthcoating affected the in-mouth residence time: chocolate A, perceived as more mouthcoating, showed an increased total chewing time and time of last swallow. Key differences across subjects were: time and number of chews, time of last swallow and total number of swallows. Subjects were grouped into three clusters of eating behaviour characterised as, "fast chewers", "thorough chewers" and "suckers". The main differences between clusters were the time chocolate was kept in mouth, chew rate and muscle work. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Handbook of Emotional & Behavioural Difficulties

    ERIC Educational Resources Information Center

    Clough, Peter; Garner, Philip; Pardeck, John T.; Yuen, Francis K.O.

    2005-01-01

    The behaviour of children in primary/elementary and secondary/high schools has been a consistent source of interest and controversy since the 19th century. As education systems in First World democracies struggle to meet changing social, economic and educational conditions, one group of children has increasingly become the focus of attention.…

  17. Detecting synchronization in coupled stochastic ecosystem networks

    NASA Astrophysics Data System (ADS)

    Kouvaris, N.; Provata, A.; Kugiumtzis, D.

    2010-01-01

    Instantaneous phase difference, synchronization index and mutual information are considered in order to detect phase transitions, collective behaviours and synchronization phenomena that emerge for different levels of diffusive and reactive activity in stochastic networks. The network under investigation is a spatial 2D lattice which serves as a substrate for Lotka-Volterra dynamics with 3rd order nonlinearities. Kinetic Monte Carlo simulations demonstrate that the system spontaneously organizes into a number of asynchronous local oscillators, when only nearest neighbour interactions are considered. In contrast, the oscillators can be correlated, phase synchronized and completely synchronized when introducing different interactivity rules (diffusive or reactive) for nearby and distant species. The quantitative measures of synchronization show that long distance diffusion coupling induces phase synchronization after a well defined transition point, while long distance reaction coupling induces smeared phase synchronization.

  18. Clustering and correlates of screen-time and eating behaviours among young adolescents.

    PubMed

    Pearson, Natalie; Griffiths, Paula; Biddle, Stuart Jh; Johnston, Julie P; McGeorge, Sonia; Haycraft, Emma

    2017-05-31

    within the home. There is a high prevalence of screen time and unhealthy eating, and screen time is coupled with unhealthy dietary behaviours. Strategies and policies are required that simultaneously address reductions in screen time and changes to habitual dietary patterns, such as TV snacking and snack availability and accessibility. These may require a combination of individual, social and environmental changes alongside conscious and more automatic (nudging) strategies.

  19. Exploring Communication Technology Behaviour of Adolescents with Cerebral Palsy in Singapore

    ERIC Educational Resources Information Center

    rasid, Nadia natasha binte mohamed; Nonis, Karen P.

    2015-01-01

    Communication among adolescents with cerebral palsy can be restricted with traditional Augmentative and Alternative Communication (AAC) device coupled with environmental and social barriers. The advance of communication technology offer solutions to reduce such barriers. Given that there is limited research in communication behaviours of…

  20. Response reactions: equilibrium coupling.

    PubMed

    Hoffmann, Eufrozina A; Nagypal, Istvan

    2006-06-01

    It is pointed out and illustrated in the present paper that if a homogeneous multiple equilibrium system containing k components and q species is composed of the reactants actually taken and their reactions contain only k + 1 species, then we have a unique representation with (q - k) stoichiometrically independent reactions (SIRs). We define these as coupling reactions. All the other possible combinations with k + 1 species are the coupled reactions that are in equilibrium when the (q - k) SIRs are in equilibrium. The response of the equilibrium state for perturbation is determined by the coupling and coupled equilibria. Depending on the circumstances and the actual thermodynamic data, the effect of coupled equilibria may overtake the effect of the coupling ones, leading to phenomena that are in apparent contradiction with Le Chatelier's principle.

  1. Three tooth kinematic coupling

    DOEpatents

    Hale, Layton C.

    2000-01-01

    A three tooth kinematic coupling based on having three theoretical line contacts formed by mating teeth rather than six theoretical point contacts. The geometry requires one coupling half to have curved teeth and the other coupling half to have flat teeth. Each coupling half has a relieved center portion which does not effect the kinematics, but in the limit as the face width approaches zero, three line contacts become six point contacts. As a result of having line contact, a three tooth coupling has greater load capacity and stiffness. The kinematic coupling has application for use in precision fixturing for tools or workpieces, and as a registration device for a work or tool changer or for optics in various products.

  2. Simulating behaviour change interventions based on the theory of planned behaviour: Impacts on intention and action.

    PubMed

    Fife-Schaw, Chris; Sheeran, Paschal; Norman, Paul

    2007-03-01

    The theory of planned behaviour (TPB; Ajzen, 1991) has been used extensively to predict social and health behaviours. However, a critical test of the TPB is whether interventions that increased scores on the theory's predictors would engender behaviour change. The present research deployed a novel technique in order to provide this test. Statistical simulations were conducted on data for 30 behaviours (N=211) that estimated the impact of interventions that generated maximum positive changes in attitudes, subjective norms and perceived behavioural control (PBC) on subsequent intentions and behaviour. Findings indicated that interventions that maximized TPB variables had a substantial impact on behavioural intentions. Although TPB maximization increased the proportion of the sample that performed respective behaviours by 28% compared with baseline, the behaviour of a substantial minority of the sample (26%) did not change. The research also identified several interactions among TPB variables in predicting simulated intention and behaviour scores and investigated the mediating role of intentions in predicting behaviour.

  3. [Sexuality among infertile couples].

    PubMed

    Alvarez-Díaz, Jorge Alberto

    2007-01-01

    A monographic type, bibliographic and hemerographic study on the sexuality in couples with fertility problems is presented. The study is based on the Rubio Aurioles' model of human sexuality, and the four holones (reproductivity, eroticism, affective bonds, gender) in couples with fertility problems are described. A review of clinical studies on the prevailing sexuality in this kind of couples and some theoretical reflections are also presented.

  4. Heightening in couple therapy.

    PubMed

    Owen, Jesse; Quirk, Kelley

    2014-03-01

    Across couple therapeutic modalities, heightening interventions have been proposed as a mechanism of change. The current article describes how behavioral and emotion-focused heightening techniques can be facilitated in couple therapy. We provide actual case examples of psychotherapist interventions aimed at heightening couples' relational or emotional interaction. Ultimately, heightening encourages couples to confront difficult topics together, express vulnerable emotions, and make new meaning of the lived experiences that might be interfering with the quality of their relationship. (c) 2014 APA, all rights reserved.

  5. Future directions in behavioural syndromes research.

    PubMed

    Bell, Alison M

    2007-03-22

    A behavioural syndrome occurs when individuals behave in a consistent way through time or across contexts and is analogous to 'personality' or 'temperament'. Interest is accumulating in behavioural syndromes owing to their important ecological and evolutionary consequences. There are plenty of opportunities in this burgeoning young field to integrate proximate and functional approaches to studying behaviour, but there are few guidelines about where to start or how to design a study on behavioural syndromes. After summarizing what we do and do not know, this brief review aims to act as a general guide for studying behavioural syndromes. Although the array of possible behavioural combinations can seem overwhelming, there are at least four different strategies that can be used to choose which behaviours or contexts to study in a behavioural syndromes view. I describe the strengths and weaknesses of these non-exclusive strategies, and then discuss the methodological and statistical issues raised by such studies.

  6. Behavioural social choice: a status report.

    PubMed

    Regenwetter, Michel; Grofman, Bernard; Popova, Anna; Messner, William; Davis-Stober, Clintin P; Cavagnaro, Daniel R

    2009-03-27

    Behavioural social choice has been proposed as a social choice parallel to seminal developments in other decision sciences, such as behavioural decision theory, behavioural economics, behavioural finance and behavioural game theory. Behavioural paradigms compare how rational actors should make certain types of decisions with how real decision makers behave empirically. We highlight that important theoretical predictions in social choice theory change dramatically under even minute violations of standard assumptions. Empirical data violate those critical assumptions. We argue that the nature of preference distributions in electorates is ultimately an empirical question, which social choice theory has often neglected. We also emphasize important insights for research on decision making by individuals. When researchers aggregate individual choice behaviour in laboratory experiments to report summary statistics, they are implicitly applying social choice rules. Thus, they should be aware of the potential for aggregation paradoxes. We hypothesize that such problems may substantially mar the conclusions of a number of (sometimes seminal) papers in behavioural decision research.

  7. Behavioural social choice: a status report

    PubMed Central

    Regenwetter, Michel; Grofman, Bernard; Popova, Anna; Messner, William; Davis-Stober, Clintin P.; Cavagnaro, Daniel R.

    2008-01-01

    Behavioural social choice has been proposed as a social choice parallel to seminal developments in other decision sciences, such as behavioural decision theory, behavioural economics, behavioural finance and behavioural game theory. Behavioural paradigms compare how rational actors should make certain types of decisions with how real decision makers behave empirically. We highlight that important theoretical predictions in social choice theory change dramatically under even minute violations of standard assumptions. Empirical data violate those critical assumptions. We argue that the nature of preference distributions in electorates is ultimately an empirical question, which social choice theory has often neglected. We also emphasize important insights for research on decision making by individuals. When researchers aggregate individual choice behaviour in laboratory experiments to report summary statistics, they are implicitly applying social choice rules. Thus, they should be aware of the potential for aggregation paradoxes. We hypothesize that such problems may substantially mar the conclusions of a number of (sometimes seminal) papers in behavioural decision research. PMID:19073478

  8. Virtual ethology of aquatic animal heterogeneous behaviours

    NASA Astrophysics Data System (ADS)

    Lim, ChenKim; Tan, KianLam

    2016-08-01

    In the virtual world, the simulation of flocking behaviour has been actively investigated since the 1980 through the boid models. However, ethology is a niche study of animal behaviour from the biological perspective that is rarely instil in the interest of the younger learners nowadays. The keystone of the research is to be able to disseminate the study of animal behaviours through the boid model with the aid of technology. Through the simulation, complex movement of animal behaviours are reproduced based on the extension of basic behaviours of boid algorithm. The techniques here are to (i) Analyse a high-level behavioural framework of motion in the animal behaviours and (ii) Evolves particles to other animal representations to portray more real-time examples of steering behaviours. Although the generality of the results is limited by the number of case study, it also supports the hypothesis that interactive simulation system of virtual ethology can aid the improvement of animal studies.

  9. Rheological behaviour of lahar flow

    NASA Astrophysics Data System (ADS)

    Lafarge, N.; Chambon, G.; Thouret, J. C.; Laigle, D.

    2012-04-01

    Lahars are mixtures of water and debris flowing down the flanks of volcanoes. These flows generally occur after heavy rainfalls and carry sediments deposited by volcanic eruptions. They are among the most destructive volcanic phenomena, and were responsible, in the 20th century, for 40% of the fatalities associated with volcanic eruptions worldwide. However, the mechanical behaviour and the propagation of these particular debris flows still remain poorly understood. In the frame of the research project Laharisk, Mount Semeru in Java (Indonesia) was chosen as a test site to monitor lahar activity and flows properties owing to the frequent occurrence of lahars on its flanks during the monsoon rainy period. Two observation stations, situated 510 m apart, were installed in the Curah Lengkong Valley on the southeast flank of Semeru volcano. The relatively straight and box-shaped channel between the two stations represents a natural flume well suited to study the hydraulics of the flows. Both stations are equipped with video cameras, pore-pressure and load sensors, AFM geophones, and one broad-band seismometer to measure the evolution over time of lahar flow height, speed, and discharge. Bucket samples are also directly taken in the flows at regular time-intervals in order to provide sediment concentration and grain-size distribution. The rheological behaviour of the material is studied through laboratory vane tests at constant imposed shear rate conducted on the fine-sized fraction (< 400 µm) of the samples. The flows generally comprise several distinct pulses or 'packets' that can be traced between the two instrumented stations. Each pulse lasts between 5 and 30 minutes. Typical flow heights, peak velocities, and maximum discharges range between 0.5-2 m, 3-6 m.s-1, and 25-250 m3.s-1, respectively. The rheometrical tests indicate a mechanical behaviour of the frictional type, the shear stress being almost independent of the shear rate. In addition, the friction

  10. Coupled analysis of a backfill hydration test

    NASA Astrophysics Data System (ADS)

    Alonso, E. E.; Lloret, A.; Delahaye, C. H.; Vaunat, J.; Gens, A.; Volckaert, G.

    1998-01-01

    BACCHUS2 in situ isothermal wetting experiment has been analysed by means of a coupled flow-deformation approach. Backfill material, a mixture of Boom clay powder and high density pellets, has been extensively tested in the laboratory in order to determine its hydraulic and mechanical properties. Parameters of constitutive equations were derived from this experimental data base. Two mechanical constitutive models have been used in the simulation of the in situ experiment: a state surface approach and an elastoplastic model. Calculations have shown several features of the hydration process which help to understand the behaviour of expansive clay barriers. Predictions using both models have been compared with each other and with actual measurement records. This has allowed a discussion of the comparative mertis of both approaches and the identification of some critical parameters of backfill behaviour. Overall agreement between calculations and field measurements is encouraging and shows the potential of the methods developed to model the behaviour of engineered clay barriers in the context of nuclear waste disposal.

  11. Tracking Optical and Electronic Behaviour of Quantum Contacts in Sub-Nanometre Plasmonic Cavities

    NASA Astrophysics Data System (ADS)

    Sanders, A.; Bowman, R. W.; Baumberg, J. J.

    2016-09-01

    Plasmonic interactions between two metallic tips are dynamically studied in a supercontinuum dark-field microscope and the transition between coupled and charge-transfer plasmons is directly observed in the sub-nm regime. Simultaneous measurement of the dc current, applied force, and optical scattering as the tips come together is used to determine the effects of conductive pathways within the plasmonic nano-gap. Critical conductances are experimentally identified for the first time, determining the points at which quantum tunnelling and conductive charge transport begin to influence plasmon coupling. These results advance our understanding of the relationship between conduction and plasmonics, and the fundamental quantum mechanical behaviours of plasmonic coupling.

  12. Tracking Optical and Electronic Behaviour of Quantum Contacts in Sub-Nanometre Plasmonic Cavities.

    PubMed

    Sanders, A; Bowman, R W; Baumberg, J J

    2016-09-09

    Plasmonic interactions between two metallic tips are dynamically studied in a supercontinuum dark-field microscope and the transition between coupled and charge-transfer plasmons is directly observed in the sub-nm regime. Simultaneous measurement of the dc current, applied force, and optical scattering as the tips come together is used to determine the effects of conductive pathways within the plasmonic nano-gap. Critical conductances are experimentally identified for the first time, determining the points at which quantum tunnelling and conductive charge transport begin to influence plasmon coupling. These results advance our understanding of the relationship between conduction and plasmonics, and the fundamental quantum mechanical behaviours of plasmonic coupling.

  13. Student Behaviour Self-Monitoring Enabling Inclusion

    ERIC Educational Resources Information Center

    Jull, Stephen K.

    2009-01-01

    Disruptive, antisocial behaviour remains an ongoing issue for all schools, and particularly those identified as inclusive. Children who exhibit elevated levels of antisocial behaviour have an increased risk of numerous negative life consequences, including impaired social relationships, escalating aggressive behaviours, substance abuse, and school…

  14. Student Behaviour Self-Monitoring Enabling Inclusion

    ERIC Educational Resources Information Center

    Jull, Stephen K.

    2009-01-01

    Disruptive, antisocial behaviour remains an ongoing issue for all schools, and particularly those identified as inclusive. Children who exhibit elevated levels of antisocial behaviour have an increased risk of numerous negative life consequences, including impaired social relationships, escalating aggressive behaviours, substance abuse, and school…

  15. Behavioural inventory of the giraffe (Giraffa camelopardalis)

    PubMed Central

    2012-01-01

    Background Numerous factors like continuous habitat reduction or fragmentation for free-ranging giraffes (Giraffa camelopardalis) as well as e.g. suboptimal housing conditions for animals in captivity might lead to behavioural alterations as part of the overall adaptation process to the changing living conditions. In order to facilitate current and future studies on giraffe behaviour, a comprehensive ethogram was compiled based on existing literature, as well as observations on giraffes in the wild (Hwange National Park, Zimbabwe; Entabeni Game Reserve, South Africa), and in captivity (National Zoological Gardens of South Africa, Pretoria). Findings The resulting ethogram lists 65 different behavioural patterns, which were described and grouped into seven categories: General activities, Abnormal repetitive behaviours, General interactions, Bull-Cow behaviour, Bull-Bull behaviour, Cow-Bull behaviour, Maternal behaviours, and Interactions by calves. The behaviours were further described regarding a presumed purpose, particularly with respect to social interactions and sexual behaviour. Contradictory descriptions from previous studies were considered and discussed in comparison with our own observations. Conclusions This ethogram provides a basis for current and future studies by suggesting a terminology which can be used for harmonizing behavioural observations, thus helping to facilitate comparability of future results. Subsequently, a better understanding of the behavioural ecology of giraffes in the wild as well as in captivity could aid future conservation efforts. PMID:23173954

  16. Short Form of the Developmental Behaviour Checklist

    ERIC Educational Resources Information Center

    Taffe, John R.; Gray, Kylie M.; Einfeld, Stewart L.; Dekker, Marielle C.; Koot, Hans M.; Emerson, Eric; Koskentausta, Terhi; Tonge, Bruce J.

    2007-01-01

    A 24-item short form of the 96-item Developmental Behaviour Checklist was developed to provide a brief measure of Total Behaviour Problem Score for research purposes. The short form Developmental Behaviour Checklist (DBC-P24) was chosen for low bias and high precision from among 100 randomly selected item sets. The DBC-P24 was developed from…

  17. Behavioural inventory of the giraffe (Giraffa camelopardalis).

    PubMed

    Seeber, Peter A; Ciofolo, Isabelle; Ganswindt, André

    2012-11-22

    Numerous factors like continuous habitat reduction or fragmentation for free-ranging giraffes (Giraffa camelopardalis) as well as e.g. suboptimal housing conditions for animals in captivity might lead to behavioural alterations as part of the overall adaptation process to the changing living conditions. In order to facilitate current and future studies on giraffe behaviour, a comprehensive ethogram was compiled based on existing literature, as well as observations on giraffes in the wild (Hwange National Park, Zimbabwe; Entabeni Game Reserve, South Africa), and in captivity (National Zoological Gardens of South Africa, Pretoria). The resulting ethogram lists 65 different behavioural patterns, which were described and grouped into seven categories: General activities, Abnormal repetitive behaviours, General interactions, Bull-Cow behaviour, Bull-Bull behaviour, Cow-Bull behaviour, Maternal behaviours, and Interactions by calves. The behaviours were further described regarding a presumed purpose, particularly with respect to social interactions and sexual behaviour. Contradictory descriptions from previous studies were considered and discussed in comparison with our own observations. This ethogram provides a basis for current and future studies by suggesting a terminology which can be used for harmonizing behavioural observations, thus helping to facilitate comparability of future results. Subsequently, a better understanding of the behavioural ecology of giraffes in the wild as well as in captivity could aid future conservation efforts.

  18. Short Form of the Developmental Behaviour Checklist

    ERIC Educational Resources Information Center

    Taffe, John R.; Gray, Kylie M.; Einfeld, Stewart L.; Dekker, Marielle C.; Koot, Hans M.; Emerson, Eric; Koskentausta, Terhi; Tonge, Bruce J.

    2007-01-01

    A 24-item short form of the 96-item Developmental Behaviour Checklist was developed to provide a brief measure of Total Behaviour Problem Score for research purposes. The short form Developmental Behaviour Checklist (DBC-P24) was chosen for low bias and high precision from among 100 randomly selected item sets. The DBC-P24 was developed from…

  19. Heterogeneity in Antisocial Behaviours and Comorbidity with Depressed Mood: A Behavioural Genetic Approach

    ERIC Educational Resources Information Center

    Rowe, Richard; Rijsdijk, Fruhling V.; Maughan, Barbara; Eley, Thalia C.; Hosang, Georgina M.

    2008-01-01

    Background: Antisocial behaviour is often comorbid with depressed mood but is itself a collection of heterogeneous behaviours. Using a genetically informative design, we examine heterogeneity in antisocial behaviour and overlaps between different forms of antisocial behaviour with depressed mood. Methods: Data were drawn from the G1219 large-scale…

  20. A Cognitive Behavioural Group Approach for Adolescents with Disruptive Behaviour in Schools

    ERIC Educational Resources Information Center

    Ruttledge, Richard A.; Petrides, K. V.

    2012-01-01

    Cognitive behavioural approaches emphasize the links between thoughts, feelings and behaviour (Greig, 2007). Previous research has indicated that these approaches are efficacious in reducing disruptive behaviour in adolescents. The aim of the current study was to provide further evaluation of cognitive behavioural group work to reduce disruptive…

  1. Heterogeneity in Antisocial Behaviours and Comorbidity with Depressed Mood: A Behavioural Genetic Approach

    ERIC Educational Resources Information Center

    Rowe, Richard; Rijsdijk, Fruhling V.; Maughan, Barbara; Eley, Thalia C.; Hosang, Georgina M.

    2008-01-01

    Background: Antisocial behaviour is often comorbid with depressed mood but is itself a collection of heterogeneous behaviours. Using a genetically informative design, we examine heterogeneity in antisocial behaviour and overlaps between different forms of antisocial behaviour with depressed mood. Methods: Data were drawn from the G1219 large-scale…

  2. A Cognitive Behavioural Group Approach for Adolescents with Disruptive Behaviour in Schools

    ERIC Educational Resources Information Center

    Ruttledge, Richard A.; Petrides, K. V.

    2012-01-01

    Cognitive behavioural approaches emphasize the links between thoughts, feelings and behaviour (Greig, 2007). Previous research has indicated that these approaches are efficacious in reducing disruptive behaviour in adolescents. The aim of the current study was to provide further evaluation of cognitive behavioural group work to reduce disruptive…

  3. Coupled trivial maps.

    PubMed

    Bunimovich, L. A.; Livi, R.; Martinez-Mekler, G.; Ruffo, S.

    1992-07-01

    The first nontrivial example of coupled map lattices that admits a rigorous analysis in the whole range of the strength of space interactions is considered. This class is generated by one-dimensional maps with a globally attracting superstable periodic trajectory that are coupled by a diffusive nearest-neighbor interaction.

  4. Gear Spline Coupling Program

    SciTech Connect

    Guo, Yi; Errichello, Robert

    2013-08-29

    An analytical model is developed to evaluate the design of a spline coupling. For a given torque and shaft misalignment, the model calculates the number of teeth in contact, tooth loads, stiffnesses, stresses, and safety factors. The analytic model provides essential spline coupling design and modeling information and could be easily integrated into gearbox design and simulation tools.

  5. Translation-coupling systems

    DOEpatents

    Pfleger, Brian; Mendez-Perez, Daniel

    2013-11-05

    Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

  6. Translation-coupling systems

    DOEpatents

    Pfleger, Brian; Mendez-Perez, Daniel

    2015-05-19

    Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

  7. Bibliographic Coupling: A Review

    ERIC Educational Resources Information Center

    Weinberg, Bella Hass

    1974-01-01

    The theory and practical applications of bibliographic coupling are reviewed. The reviewer takes issue with the use of bibliographic coupling for information retrieval and automatic classification on logical grounds, and for reasons relating to uncontrolled citation practices. The usefulness of the procedure for the study of the science of science…

  8. Vasopressin, oxytocin and social behaviour.

    PubMed

    Keverne, Eric B; Curley, James P

    2004-12-01

    Understanding the neurobiology of social behaviour in mammals has been considerably advanced by the findings from two species of vole, one of which is monogamous and pair bonds whereas the other species is promiscuous and fails to form any long-lasting social relationships. The combination of neurobehavioural studies and molecular genetics has determined behavioural differences between the two species linked to the neural distribution of vasopressin 1A receptor in the male brain. More importantly, vasopressin 1A receptor gene transfer including the upstream regulatory sequence has enhanced male social affiliation in a non-monogamous species. Male affiliative bonding depends upon release of both vasopressin and dopamine in the ventral striatum enhancing the reward value of odour cues that signal identity.

  9. Midbrain circuits for defensive behaviour.

    PubMed

    Tovote, Philip; Esposito, Maria Soledad; Botta, Paolo; Chaudun, Fabrice; Fadok, Jonathan P; Markovic, Milica; Wolff, Steffen B E; Ramakrishnan, Charu; Fenno, Lief; Deisseroth, Karl; Herry, Cyril; Arber, Silvia; Lüthi, Andreas

    2016-06-09

    Survival in threatening situations depends on the selection and rapid execution of an appropriate active or passive defensive response, yet the underlying brain circuitry is not understood. Here we use circuit-based optogenetic, in vivo and in vitro electrophysiological, and neuroanatomical tracing methods to define midbrain periaqueductal grey circuits for specific defensive behaviours. We identify an inhibitory pathway from the central nucleus of the amygdala to the ventrolateral periaqueductal grey that produces freezing by disinhibition of ventrolateral periaqueductal grey excitatory outputs to pre-motor targets in the magnocellular nucleus of the medulla. In addition, we provide evidence for anatomical and functional interaction of this freezing pathway with long-range and local circuits mediating flight. Our data define the neuronal circuitry underlying the execution of freezing, an evolutionarily conserved defensive behaviour, which is expressed by many species including fish, rodents and primates. In humans, dysregulation of this 'survival circuit' has been implicated in anxiety-related disorders.

  10. The thermal behaviour of liottite

    NASA Astrophysics Data System (ADS)

    Ballirano, Paolo

    2012-02-01

    Thermal behaviour of liottite, the ABABAC six-layer member of the cancrinite-sodalite supergroup, has been investigated in situ real- time using laboratory parallel-beam X-ray powder diffraction data. Thermal expansion has been analysed from 323 to 1,223 K with temperature steps of 25 K. Dependence of the hexagonal cell parameters from temperature indicates a different behaviour with respect to afghanite, an ABABACAC eight-layer member of the supergroup. Three different regimes were observed, the last coincident with the starting of the conversion of liottite to haüyne (prevailing) and leucite-HT (minor). A smaller thermal expansion as compared to afghanite was observed. Isothermal annealing at 1,173 K led to a more extended conversion to haüyne, an a-parameter contraction, and a c-parameter expansion with respect to the starting RT cell parameters.

  11. Ground energy coupling

    NASA Astrophysics Data System (ADS)

    Metz, P. D.

    The feasibility of ground coupling for various heat pump systems was investigated. Analytical heat flow models were developed to approximate design ground coupling devices for use in solar heat pump space conditioning systems. A digital computer program called GROCS (GRound Coupled Systems) was written to model 3-dimensional underground heat flow in order to simulate the behavior of ground coupling experiments and to provide performance predictions which have been compared to experimental results. GROCS also has been integrated with TRNSYS. Soil thermal property and ground coupling device experiments are described. Buried tanks, serpentine earth coils in various configurations, lengths and depths, and sealed vertical wells are being investigated. An earth coil used to heat a house without use of resistance heating is described.

  12. Coupled nano-plasmons

    NASA Astrophysics Data System (ADS)

    Apostol, M.; Ilie, S.; Petrut, A.; Savu, M.; Toba, S.

    2014-05-01

    A simple model of coupled plasmons arising in two neighbouring nano-particles is presented. The coupled oscillations and the corresponding eigenfrequencies are computed. It is shown that the plasmons may be periodically transferred between the two particles. For larger separation distances between the two particles the retardation is included. The oscillation eigenmodes are the polaritons in this case. There are distances for which the particles do not couple to each other, i.e. the polaritonic coupling gets damped. The van der Waals-London-Casimir force is estimated for the two particles; it is shown that for large distances the force is repulsive. We compute also the polarizabilities of the two coupled nano-particles and their cross-section under the action of an external monochromatic plane wave, which exhibit resonances indicative of light trapping and field enhancement. A resonant force is also identified, acting upon the particles both on behalf of the external field and of each other.

  13. [Genes for extreme violent behaviour?].

    PubMed

    Jordan, Bertrand

    2015-01-01

    A new genetic study focussing on the degree of violence in criminals and using both candidate gene and GWAS approaches finds statistically significant associations of extreme violent behaviour with low activity alleles of monoamine oxydase A (MAOA) and with the CD13 gene. However, the alleles implicated are common in the general population, thus they cannot be causal, and only represent potential indicators of increased risk.

  14. Assistive technology--behaviourally assisted.

    PubMed

    Benton, S; Manning, B

    2006-01-01

    In considering the recurrent problems involved in technology led initiatives within the public sector, this paper seeks to identify change management requirements needed to help avoid these latent pitfalls in the widespread introduction of Assistive Technology. It develops a change process approach based on current clinical psychology techniques used in assessing sources and level of resistance to behavioural change and applies them to managing effective benefits realisation.

  15. Strong Coupling Continuum QCD

    SciTech Connect

    Michael Pennington

    2011-05-01

    The Schwinger-Dyson, Bethe-Salpeter system of equations are the link between coloured quarks and gluons, and colourless hadrons and their properties. This talk reviews some aspects of these studies from the infrared behaviour of ghosts to the prediction of electromagnetic form-factors.

  16. Strong Coupling Continuum QCD

    SciTech Connect

    Pennington, M. R.

    2011-05-23

    The Schwinger-Dyson, Bethe-Salpeter system of equations are the link between coloured quarks and gluons, and colourless hadrons and their properties. This talk reviews some aspects of these studies from the infrared behaviour of ghosts to the prediction of electromagnetic form-factors.

  17. Mood, eating behaviour and attention.

    PubMed

    Williams, J M G; Healy, H; Eade, J; Windle, G; Cowen, P J; Green, M W; Durlach, P

    2002-04-01

    Obesity is a growing health problem, but most people find dieting unsuccessful. Three studies examine possible reasons for the difficulty and the extent to which dieting-related reductions in cognitive function are associated with mood and well-being. In Study One, 49 female dieters were compared with a control group of 31 matched non-dieters on measures of well-being, mood, eating behaviour (Dutch Eating Behaviour Questionnaire), and attention. Study Two examined two measures of restraint to examine why previous studies find high restrainers are prone to react to emotion. Study Three experimentally manipulated mood using music and the standard Velten Induction Procedure to examine attention in restrainers and emotional eaters. Dieting was found to be associated with deficits in sustained attention. This finding was further supported by the demonstration of a significant impairment in performance following a negative mood induction in high emotional eaters whereas high restrainers were relatively unaffected by the mood challenge. We suggest that different aspects of eating behaviour have dissociable effects on cognitive-affective function. Trait tendencies to restrained eating are associated with attentional deficits, but are not further affected by mood disruption. It is the long-term tendency to eat when emotional that combines with current emotional state to trigger cognitive deficits.

  18. Preschoolers’ Dietary Behaviours: Parents’ Perspectives

    PubMed Central

    TUCKER, PATRICIA; IRWIN, JENNIFER D.; HE, MEIZI; BOUCK, L. MICHELLE SANGSTER; POLLETT, GRAHAM

    2016-01-01

    Purpose Preschoolers’ dietary intake behaviours are described from the perspective of their parents. Methods A maximum variation sample of 71 parents of preschoolers participated in this qualitative study. Ten semi-structured focus group interviews were conducted. Two experienced moderators facilitated all focus groups, which were audio-recorded and transcribed verbatim. Strategies to ensure trustworthiness of the data were employed throughout the study. Two team members independently performed inductive content analysis. NVivo software was used to code the emerging themes. Results Parents identified food and food issues as key health-related behaviours among preschoolers. Parents discussed challenges to healthy eating, including time limitations and societal pressures, as well as methods for facilitating healthy food choices, including bribery, education, and being creative with food. Conclusions Dietary intake is on the minds of preschoolers’ parents. Unfortunately, some methods that parents currently use to promote healthy food choices may be more detrimental than beneficial for children in the long term. Parents’ keen interest in their preschoolers’ eating habits may make them particularly receptive to learning about and facilitating healthy choices in more behaviourally appropriate ways. Widespread educational messages about the benefits and detriments of various strategies to facilitate healthy eating among preschoolers therefore seem warranted. PMID:16759432

  19. Surgery to modify nutritional behaviour.

    PubMed

    García-Caballero, M

    2005-01-01

    The main aim of obesity surgery is to change the dietary habits of morbidly obese patients. These are patients whose dietary habits nutritionists and psychologists have not been able to change during previous decades. The history of this surgery can teach us many important lessons. For example, procedures that have focused on effecting a malabsorptive state, but without addressing any behavioural mechanism for weight control, such as jejunoileal bypass, have failed. On the other hand, those that have centered on only addressing behavioural issues, the purely restrictive, are also difficult for patients to comply with and also have a high failure rate. To facilitate a change in the nutritional behaviour of morbidly obese patients which can lead to the loss of an adequate amount of weight, and which could be maintained in the long term is difficult. We need to stimulate changes that can be easily followed by the patient, and at the same time, provoke minimal medium and long term alterations in their nutritional state. To achieve and maintain this aim efficiently, it is necessary that the patients have confidence in and respect the physician, so that they can follow strictly their medical advice.

  20. Differences in sexual behaviour between HIV-infected pregnant women and their husbands in Bangkok, Thailand.

    PubMed

    Bennetts, A; Shaffer, N; Phophong, P; Chaiyakul, P; Mock, P A; Neeyapun, K; Bhadrakom, C; Mastro, T D

    1999-12-01

    In a Bangkok antenatal clinic, we interviewed 102 HIV-infected pregnant women and their husbands, 30% of whom were HIV-negative. We evaluated these data by matched and unmatched analysis, compared men and women in stable couple relationships on a number of sociodemographic and risk factor indicators and investigated further whether there were any differences in sociodemographic or risk factor profiles between HIV-serodiscordant couples and seroconcordant couples. When compared to wives, more of the husbands were working (p = 0.001), earning more money (p = 0.001), had had more than two sex partners (p = 0.001) and had had syphilis (p = 0.001). Serodiscordant couples did not differ greatly from seroconcordant couples except that women married to HIV-negative men were more likely to have been divorced or separated than their husbands which was not the case for women married to HIV-positive men (p = 0.02). There was poor agreement between husband and wife reports of husband risk behaviour and this did not differ between concordant and discordant couples. These findings suggest that assessment of risk and counselling of Thai women is incomplete without information on the HIV status and risk behaviour of her partner. Prevention strategies to decrease heterosexual transmission among couples need to target both the man and the woman.

  1. Phenomenology and treatment of behavioural addictions.

    PubMed

    Grant, Jon E; Schreiber, Liana R N; Odlaug, Brian L

    2013-05-01

    Behavioural addictions are characterized by an inability to resist an urge or drive resulting in actions that are harmful to oneself or others. Behavioural addictions share characteristics with substance and alcohol abuse, and in areas such as natural history, phenomenology, and adverse consequences. Behavioural addictions include pathological gambling, kleptomania, pyromania, compulsive buying, compulsive sexual behaviour, Internet addiction, and binge eating disorder. Few studies have examined the efficacy of pharmacological and psychological treatment for the various behavioural addictions, and therefore, currently, no treatment recommendations can be made.

  2. Genetics and criminal behaviour: recent accomplishments.

    PubMed

    Lagoa, Arlindo; Santos, Agostinho; Pinheiro, M Fátima; Magalhães, Teresa

    2009-10-01

    The past two decades have seen an explosion in research in the fields of violence and behavioural genetics. Advances in human genetics have raised the possibility that genetic mechanisms can explain various aspects of human criminal and aggressive behaviour. However, this new knowledge can pose enormous challenges concerning the moral and legal conceptions of free will and responsibility. This paper reviews the main aspects of behavioural genetics, focusing on criminal and aggressive behaviour and describes the most important genes known to influence this behaviour.

  3. Consistent behavioural traits and behavioural syndromes in pairs of the false clown anemonefish Amphiprion ocellaris.

    PubMed

    Wong, M Y L; Medina, A; Uppaluri, C; Arnold, S; Seymour, J R; Buston, P M

    2013-07-01

    Using the social clown anemonefish Amphiprion ocellaris, whether individuals exhibited consistency in activity levels, boldness and sociability in a paired context, and whether these three behavioural traits were positively correlated within a single behavioural syndrome, was investigated. The results highlight that consistent individual differences in behaviour are expressed in a social fish and suggest that consistent behavioural traits and behavioural syndromes could influence the structure and functioning of their societies.

  4. Chimera and phase-cluster states in populations of coupled chemical oscillators

    NASA Astrophysics Data System (ADS)

    Tinsley, Mark R.; Nkomo, Simbarashe; Showalter, Kenneth

    2012-09-01

    Populations of coupled oscillators may exhibit two coexisting subpopulations, one with synchronized oscillations and the other with unsynchronized oscillations, even though all of the oscillators are coupled to each other in an equivalent manner. This phenomenon, discovered about ten years ago in theoretical studies, was then further characterized and named the chimera state after the Greek mythological creature made up of different animals. The highly counterintuitive coexistence of coherent and incoherent oscillations in populations of identical oscillators, each with an equivalent coupling structure, inspired great interest and a flurry of theoretical activity. Here we report on experimental studies of chimera states and their relation to other synchronization states in populations of coupled chemical oscillators. Our experiments with coupled Belousov-Zhabotinsky oscillators and corresponding simulations reveal chimera behaviour that differs significantly from the behaviour found in theoretical studies of phase-oscillator models.

  5. Designing interventions to change eating behaviours.

    PubMed

    Atkins, Lou; Michie, Susan

    2015-05-01

    Understanding and changing eating behaviours are central to the work of Nutrition Society members working in both research and applied settings. The present paper describes a recently published resource to guide the design of interventions to change behaviour, The Behaviour Change Wheel: A Guide to Designing Interventions (BCW Guide). This is a practical guide to intervention design that brings together recently-developed theory-based tools in behavioural science into a coherent step-by-step design process. It is based on the BCW, a synthesis of nineteen frameworks of behaviour change found in the research literature. The BCW has at its core a model of behaviour known as 'capability', 'opportunity', 'motivation' and 'behaviour'. The model recognises that behaviour is part of an interacting system involving all these components. The BCW identifies different intervention options that can be applied to changing each of the components and policies that can be adopted to deliver those intervention options. The book shows how the BCW links to theory-based frameworks to understand behaviour such as the Theoretical Domains Framework and the recently developed Behaviour Change Technique Taxonomy v1 for specifying intervention content. In essence, it shows how to link what is understood about a given behaviour to types of intervention likely to be effective and then translate this into a locally relevant intervention. In addition, the present paper sets out some principles of intervention design.

  6. Depression: The Differing Narratives of Couples in Couple Therapy

    ERIC Educational Resources Information Center

    Rautiainen, Eija-Liisa; Aaltonen, Jukka

    2010-01-01

    How does the spouse of a person with depression take part in constructing narratives of depression in couple therapy? In this study we examined couples' ways of co-constructing narratives of depression in couple therapy. Three couple therapy processes were chosen for the study, one spouse in each couple having been referred to an outpatient clinic…

  7. Diagnostic instruments for behavioural addiction: an overview

    PubMed Central

    Albrecht, Ulrike; Kirschner, Nina Ellen; Grüsser, Sabine M.

    2007-01-01

    In non-substance-related addiction, the so-called behavioural addiction, no external psychotropic substances are consumed. The psychotropic effect consists of the body’s own biochemical processes induced only by excessive activities. Until recently, knowledge was limited with respect to clinically relevant excessive reward-seeking behaviour, such as pathological gambling, excessive shopping and working which meet diagnostic criteria of dependent behaviour. To date, there is no consistent concept for diagnosis and treatment of excessive reward-seeking behaviour, and its classification is uncertain. Therefore, a clear conceptualization of the so-called behavioural addictions is of great importance. The use of adequate diagnostic instruments is necessary for successful therapeutical implications. This article provides an overview of the current popular diagnostic instruments assessing the different forms of behavioural addiction. Especially in certain areas there are only few valid and reliable instruments available to assess excessive rewarding behaviours that fulfill the criteria of addiction. PMID:19742294

  8. Teaching dental undergraduates behaviour change skills.

    PubMed

    McGoldrick, P M; Pine, C M; Mossey, P A

    1998-08-01

    This paper describes an active learning-based education tool which enables dental students to learn preventive techniques relevant to patient dental health behaviour. 2 studies were conducted involving 33, 2nd year (study 1) and 9, 3rd year (study 2) undergraduate dental students. In study 1, snacking behaviour and its antecedents were analysed from detailed 3-day diet diaries completed by the students. Study 2 entailed the students changing one aspect of their sugar/diet behaviour using self-management techniques. It is concluded that dental students can successfully (a) identify antecedents to sugar snacking behaviours on several levels, i.e., cognitive, emotional and situational, (b) set goals and use behaviour change techniques to modify these behaviours, and (c) appreciate that this experience is relevant to similar preventive techniques that they will use in clinical practice. Training in the application of these skills to their own maladaptive behaviours provides a strong educational tool based on psycho-educational theories.

  9. Mouse behavioural analysis in systems biology

    PubMed Central

    van Meer, Peter; Raber, Jacob

    2005-01-01

    Molecular techniques allowing in vivo modulation of gene expression have provided unique opportunities and challenges for behavioural studies aimed at understanding the function of particular genes or biological systems under physiological or pathological conditions. Although various animal models are available, the laboratory mouse (Mus musculus) has unique features and is therefore a preferred animal model. The mouse shares a remarkable genetic resemblance and aspects of behaviour with humans. In this review, first we describe common mouse models for behavioural analyses. As both genetic and environmental factors influence behavioural performance and need to be carefully evaluated in behavioural experiments, considerations for designing and interpretations of these experiments are subsequently discussed. Finally, common behavioural tests used to assess brain function are reviewed, and it is illustrated how behavioural tests are used to increase our understanding of the role of histaminergic neurotransmission in brain function. PMID:16035954

  10. A scanning transmon qubit for strong coupling circuit quantum electrodynamics.

    PubMed

    Shanks, W E; Underwood, D L; Houck, A A

    2013-01-01

    Like a quantum computer designed for a particular class of problems, a quantum simulator enables quantitative modelling of quantum systems that is computationally intractable with a classical computer. Superconducting circuits have recently been investigated as an alternative system in which microwave photons confined to a lattice of coupled resonators act as the particles under study, with qubits coupled to the resonators producing effective photon-photon interactions. Such a system promises insight into the non-equilibrium physics of interacting bosons, but new tools are needed to understand this complex behaviour. Here we demonstrate the operation of a scanning transmon qubit and propose its use as a local probe of photon number within a superconducting resonator lattice. We map the coupling strength of the qubit to a resonator on a separate chip and show that the system reaches the strong coupling regime over a wide scanning area.

  11. Balancing selection shapes density-dependent foraging behaviour.

    PubMed

    Greene, Joshua S; Brown, Maximillian; Dobosiewicz, May; Ishida, Itzel G; Macosko, Evan Z; Zhang, Xinxing; Butcher, Rebecca A; Cline, Devin J; McGrath, Patrick T; Bargmann, Cornelia I

    2016-11-10

    The optimal foraging strategy in a given environment depends on the number of competing individuals and their behavioural strategies. Little is known about the genes and neural circuits that integrate social information into foraging decisions. Here we show that ascaroside pheromones, small glycolipids that signal population density, suppress exploratory foraging in Caenorhabditis elegans, and that heritable variation in this behaviour generates alternative foraging strategies. We find that natural C. elegans isolates differ in their sensitivity to the potent ascaroside icas#9 (IC-asc-C5). A quantitative trait locus (QTL) regulating icas#9 sensitivity includes srx-43, a G-protein-coupled icas#9 receptor that acts in the ASI class of sensory neurons to suppress exploration. Two ancient haplotypes associated with this QTL confer competitive growth advantages that depend on ascaroside secretion, its detection by srx-43 and the distribution of food. These results suggest that balancing selection at the srx-43 locus generates alternative density-dependent behaviours, fulfilling a prediction of foraging game theory.

  12. Contactless Rotary Electrical Couplings

    NASA Technical Reports Server (NTRS)

    Kumagai, Hiroyuki

    2003-01-01

    Rotary electrical couplings based on induction (transformer action) rather than conduction between rotating and stationary circuitry have been invented. These couplings provide an alternative to slip rings and contact brushes. Mechanical imperfections of slip-ring and brush contact surfaces and/or dust particles trapped between these surfaces tend to cause momentary interruptions in electrical contact and thereby give rise to electrical noise. This source of noise can be eliminated in the inductive rotary couplings because no direct contact is necessary for transformer action.

  13. Beyond single behaviour theory: Adding cross-behaviour cognitions to the health action process approach.

    PubMed

    Fleig, Lena; Ngo, Joy; Roman, Blanca; Ntzani, Evangelia; Satta, Paolo; Warner, Lisa M; Schwarzer, Ralf; Brandi, Maria L

    2015-11-01

    Commonly, health behaviour theories have been applied to single behaviours, giving insights into specific behaviours but providing little knowledge on how individuals pursue an overall healthy lifestyle. In the context of diet and physical activity, we investigated the extent to which cross-behaviour cognitions, namely transfer cognitions and compensatory health beliefs, contribute to single behaviour theory. A total of 767 participants from two European regions (i.e., Germany n = 351, southern Europe n = 416) completed online questionnaires on physical activity and healthy dietary behaviour, behaviour-specific cognitions (i.e., self-efficacy, outcome expectancies, risk perception, intention, action planning, action control), as well as cross-behaviour cognitions, namely transfer cognitions and compensatory health beliefs. Nested path models were specified to investigate the importance of cross-behaviour cognitions over and above behaviour-specific predictors of physical activity and healthy nutrition. Across both health behaviours, transfer cognitions were positively associated with intention and self-regulatory strategies. Compensatory health beliefs were negatively associated with intention. Action planning and action control mediated the effect of intentions on behaviour. Cross-behaviour cognitions contribute to single behaviour theory and may explain how individuals regulate more than one health behaviour. Statement of contribution What is already known on this subject? Cross-behaviour cognitions are related to a healthy lifestyle. Compensatory health beliefs hinder the adoption of a healthy lifestyle. Transfer cognitions encourage the engagement in a healthy lifestyle. What does this study add? Transfer cognitions were positively associated with intentions, action planning, and action control over and above behaviour-specific cognitions. Compensatory health beliefs were related to intentions only. Both facilitating and debilitating cross-behaviour cognitions

  14. Perceived criticism: associations with perceiver characteristics and interpersonal behaviour.

    PubMed

    Gerlsma, Coby; van Duijn, Marijtje A J; Hale, William W; van Hout, Wiljo J P J

    2009-12-30

    Perceived Criticism (PC) evolved in the context of Expressed Emotion (EE) research and, like EE, predicts the course of various psychiatric disorders. However, little is known about PC's validity. We examined (in Study 1) to what extent PC reflects the perceiver's current depressive and marital complaints, whether PC measures reciprocal criticism that characterizes dyads rather than individuals, and (in Study 2) whether PC reflects actual interactive behaviour. Both studies compared a single-item with a multi-item measure of PC. In Study 1, general community couples completed self-reports of PC, depressed mood, and marital dissatisfaction, and expressed their feelings in a brief EE interview (Five Minute Speech Samples). Multilevel analyses suggested that PC was associated with both partners' expressions of criticism, and the perceiver's depressive and marital complaints. In Study 2, general community couples completed self-reports of PC and participated in a videotaped problem solving interaction. Interactions were coded with the Kategorien system für partnerschaftliche Interaktion (KPI). PC was related to the partner's verbal and nonverbal expression of criticism and the perceiver's expression of nonverbal negative behaviour. Overall, the pattern of findings fits in well with theoretical formulations regarding EE, and supports the usefulness of PC measures as practical alternatives for the assessment of EE.

  15. Increased anterior cingulate cortex response precedes behavioural adaptation in anorexia nervosa

    PubMed Central

    Geisler, Daniel; Ritschel, Franziska; King, Joseph A.; Bernardoni, Fabio; Seidel, Maria; Boehm, Ilka; Runge, Franziska; Goschke, Thomas; Roessner, Veit; Smolka, Michael N.; Ehrlich, Stefan

    2017-01-01

    Patients with anorexia nervosa (AN) are characterised by increased self-control, cognitive rigidity and impairments in set-shifting, but the underlying neural mechanisms are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to elucidate the neural correlates of behavioural adaptation to changes in reward contingencies in young acutely ill AN patients. Thirty-six adolescent/young adult, non-chronic female AN patients and 36 age-matched healthy females completed a well-established probabilistic reversal learning task during fMRI. We analysed hemodynamic responses in empirically-defined regions of interest during positive feedback and negative feedback not followed/followed by behavioural adaptation and conducted functional connectivity analyses. Although overall task performance was comparable between groups, AN showed increased shifting after receiving negative feedback (lose-shift behaviour) and altered dorsal anterior cingulate cortex (dACC) responses as a function of feedback. Specifically, patients had increased dACC responses (which correlated with perfectionism) and task-related coupling with amygdala preceding behavioural adaption. Given the generally preserved task performance in young AN, elevated dACC responses specifically during behavioural adaption is suggestive of increased monitoring for the need to adjust performance strategies. Higher dACC-amygdala coupling and increased adaptation after negative feedback underlines this interpretation and could be related to intolerance of uncertainty which has been suggested for AN. PMID:28198813

  16. Increased anterior cingulate cortex response precedes behavioural adaptation in anorexia nervosa.

    PubMed

    Geisler, Daniel; Ritschel, Franziska; King, Joseph A; Bernardoni, Fabio; Seidel, Maria; Boehm, Ilka; Runge, Franziska; Goschke, Thomas; Roessner, Veit; Smolka, Michael N; Ehrlich, Stefan

    2017-02-13

    Patients with anorexia nervosa (AN) are characterised by increased self-control, cognitive rigidity and impairments in set-shifting, but the underlying neural mechanisms are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to elucidate the neural correlates of behavioural adaptation to changes in reward contingencies in young acutely ill AN patients. Thirty-six adolescent/young adult, non-chronic female AN patients and 36 age-matched healthy females completed a well-established probabilistic reversal learning task during fMRI. We analysed hemodynamic responses in empirically-defined regions of interest during positive feedback and negative feedback not followed/followed by behavioural adaptation and conducted functional connectivity analyses. Although overall task performance was comparable between groups, AN showed increased shifting after receiving negative feedback (lose-shift behaviour) and altered dorsal anterior cingulate cortex (dACC) responses as a function of feedback. Specifically, patients had increased dACC responses (which correlated with perfectionism) and task-related coupling with amygdala preceding behavioural adaption. Given the generally preserved task performance in young AN, elevated dACC responses specifically during behavioural adaption is suggestive of increased monitoring for the need to adjust performance strategies. Higher dACC-amygdala coupling and increased adaptation after negative feedback underlines this interpretation and could be related to intolerance of uncertainty which has been suggested for AN.

  17. A picture for the coupling of unemployment and inflation

    NASA Astrophysics Data System (ADS)

    Safdari, H.; Hosseiny, A.; Vasheghani Farahani, S.; Jafari, G. R.

    2016-02-01

    The aim of this article is to illustrate the scaling features of two well heard characters in the media; unemployment and inflation. We carry out a scaling analysis on the coupling between unemployment and inflation. This work is based on the wavelet analysis as well as the detrended fluctuation analysis (DFA). Through our analysis we state that while unemployment is time scale invariant, inflation is bi-scale. We show that inflation possess a five year time scale where it experiences different behaviours before and after this scale period. This behaviour of inflation provides basis for the coupling to inherit the stated time interval. Although inflation is bi-scale, it is unemployment that shows a strong multifractality feature. Owing to the cross wavelet analysis we provide a picture that illustrates the dynamics of coupling between unemployment and inflation regarding intensity, direction, and scale. The fact of the matter is that the coupling between inflation and unemployment is not equal in one way compared to the opposite. Regarding the scaling; coupling exhibits different features in various scales. In a sense that although in one scale its correlation behaves in a positive/negative manner, at the same time it can be negative/positive for another scale.

  18. Disformally coupled inflation

    SciTech Connect

    De Bruck, Carsten van; Longden, Chris; Koivisto, Tomi E-mail: timoko@kth.se

    2016-03-01

    A disformal coupling between two scalar fields is considered in the context of cosmological inflation. The coupling introduces novel derivative interactions mixing the kinetic terms of the fields but without introducing superluminal or unstable propagation of the two scalar fluctuation modes. Though the typical effect of the disformal coupling is to inhibit one of the fields from inflating the universe, the energy density of the other field can drive viable near Sitter -inflation in the presence of nontrivial disformal dynamics, in particular when one assumes exponential instead of power-law form for the couplings. The linear perturbation equations are written for the two-field system, its canonical degrees of freedom are quantised, their spectra are derived and the inflationary predictions are reported for numerically solved exponential models. A generic prediction is low tensor-to-scalar ratio.

  19. The coupling of engines

    NASA Technical Reports Server (NTRS)

    Boccaccio, Paul

    1921-01-01

    This report examines the idea of coupling numerous engines together to turn a single propeller, which the author feels would free aircraft design from the problems of multi-engine and propeller design.

  20. Coupling in the Tevatron

    SciTech Connect

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-{beta} quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note.

  1. Connecting behaviour and performance: the evolution of biting behaviour and bite performance in bats.

    PubMed

    Santana, S E; Dumont, E R

    2009-11-01

    Variation in behaviour, performance and ecology are traditionally associated with variation in morphology. A neglected part of this ecomorphological paradigm is the interaction between behaviour and performance, the ability to carry out tasks that impact fitness. Here we investigate the relationship between biting behaviour and performance (bite force) among 20 species of ecologically diverse bats. We studied the patterns of evolution of plasticity in biting behaviour and bite force, and reconstructed ancestral states for behaviour and its plasticity. Both behavioural and performance plasticity exhibited accelerating evolution over time, and periods of rapid evolution coincided with major dietary shifts from insect-feeding to plant-feeding. We found a significant, positive correlation between behavioural plasticity and bite force. Bats modulated their performance by changing their biting behaviour to maximize bite force when feeding on hard foods. The ancestor of phyllostomids was likely a generalist characterized by high behavioural plasticity, a condition that also evolved in specialized frugivores and potentially contributed to their diversification.

  2. The relation of social behaviours and challenging behaviours in infants and toddlers with Autism Spectrum Disorders.

    PubMed

    Matson, Johnny L; Neal, Daniene; Fodstad, Jill C; Hess, Julie A

    2010-01-01

    Challenging behaviours are a commonly co-occuring problem in children with ASD and are often present during the toddler years. The relationship that these challenging behaviours have with core features of ASD, specifically social behaviours, was examined in this study. This study analysed the relationship between socialization and challenging behaviours among 153 toddlers with autism spectrum disorder. Social behaviour was evaluated using the Battelle Developmental Inventory, 2nd Edition and challenging behaviours were assessed using Baby and Infant Screen for Children with aUtIsm Traits, Part 3. Lower levels of adult interaction and peer interaction were associated with higher levels of stereotypic behaviour, aggressive/destructive behaviour and to a lesser extent self-injury. The nature of the relationships between socialization and challenging behaviours likely interact in several ways. A better understanding of these relationships is essential to early identification and treatment of children with ASD.

  3. The developmental relation between aggressive behaviour and prosocial behaviour: A 5-year longitudinal study.

    PubMed

    Obsuth, Ingrid; Eisner, Manuel P; Malti, Tina; Ribeaud, Denis

    2015-01-01

    Past research has shown links between both children's aggressive behaviour and a lack of prosocial behaviour to later maladaptation. Both types of behaviours have also been identified as crucial in children's social and emotional development and later (mal)adaptation. However, little is known about the way they predict each other over time. We utilised a large, ethnically diverse, longitudinal population sample of girls and boys (N = 1,334) to examine the bidirectional cross-lagged links between aggressive and prosocial domains of behaviour from age seven to eleven. Teacher, parent and child self-reports were utilised to assess aggressive behaviour and prosocial behaviour. The results revealed that aggressive behaviour measured one year predicted decreases in prosocial behaviour in the following year. Conversely, prosocial behaviour did not predict changes in aggressive behaviour in the subsequent year. Furthermore, peer difficulties were examined and found to be an important mediator of the link between aggressive and prosocial behaviour. Specifically, peer difficulties mediated the links between aggressive behaviour and prosocial behaviour one year later, particularly during the first three years of school attendance. Implications of the findings for the design of intervention strategies to reduce children's aggressive behaviour are discussed.

  4. Gain Coupling VECSELs (POSTPRINT)

    DTIC Science & Technology

    2013-01-01

    AFRL-RY-WP-TP-2013-0028 GAIN COUPLING VECSELs (POSTPRINT) Robert Bedford Optoelectronic Technology Branch Aerospace Components...COUPLING VECSELs (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62204F 6. AUTHOR(S) Robert Bedford...Clearance Date 28 December 2012. Report contains color. 14. ABSTRACT Vertical external cavity surface emitting lasers ( VECSELs ) provide a flexible

  5. Module coupling and predictability

    NASA Astrophysics Data System (ADS)

    Knopf, B.; Held, H.

    2003-04-01

    Successive coupling of several nonlinear submodules seems to be the implicit master strategy of the current world-wide modelling endeavour. The process of coupling is investigated by using different methods of examining low order coupled atmosphere-ocean systems. As a first step, a coupled atmosphere-ocean system, based on the Lorenz84 atmosphere is considered, operated in a forced versus the truly coupled mode. In [1] it is shown that forcing cannot emulate the fully coupled system, yet quite the contrary, generates time series of intermittently high predictability ("locking"). Standard linear stability analysis is incapable to explain the locking phenomenon. While regions of linear asymptotic stability can be evaluated, it turns out that this criterion is too conservative and does not explain the standard locking situation, as the trajectory periodically leaves the region of stability during a locking phase. We therefore propose that the locking phenomenon needs to be analysed in the framework of non-linear dynamics. Preliminary analysis of the statistic of locking-periods displays a similarity to type III intermittency. Bifurcation diagrams obtained from the continuation software AUTO indicate a rich phase space structure which makes the interpretation of the locking phenomenon intricate. Systematic variation of coupling constants appears to be a promising task as the key effects could be followed into parameter regimes of more transparent phase space structure. begin{thebibliography}{0} bibitem{Wittenberg98}A. T. Wittenberg, J. L. Anderson. Dynamical implications of prescribing part of a coupled system: Results from a low order model. Nonlinear Processes in Geophysics, 5: 167-179, 1998.

  6. Predicting behaviour from perceived behavioural control: tests of the accuracy assumption of the theory of planned behaviour.

    PubMed

    Sheeran, Paschal; Trafimow, David; Armitage, Christopher J

    2003-09-01

    The theory of planned behaviour assumes that the accuracy of perceived behavioural control (PBC) determines the strength of the PBC-behaviour relationship. However, this assumption has never been formally tested. The present research developed and validated a proxy measure of actual control (PMAC) in order to test the assumption. In two studies, participants completed measures of intention and PBC, and subsequently completed measures of behaviour and the PMAC. Validity of the PMAC was established by findings showing; (a). that the PMAC moderated the intention-behaviour relation, and (b). that PMAC scores did not reflect attributions for participants' failure to enact their stated intentions. Accuracy was operationalized as the difference between PBC and PMAC scores. Consistent with theoretical expectations, several analyses indicated that greater accuracy of PBC was associated with improved prediction of behaviour by PBC.

  7. Cognitive behaviour therapy for schizophrenia

    PubMed Central

    Lecomte, Tania

    2012-01-01

    Schizophrenia is one of the major and potentially severe mental illnesses. Even with best practices, there are limitations to the effectiveness of treatments that include medications for this disorder. Relapse rates are high and often those with the illness remain symptomatic and functionally impaired. All the evidence suggests that individuals with schizophrenia do best with a combination of pharmacological and psychosocial intervention. One psychosocial treatment that has received much attention is cognitive behaviour therapy (CBT). This brief review will address what we know about the use and effectiveness of CBT at all phases of schizophrenia and its strengths, weaknesses and its future. PMID:22403587

  8. Social behaviour in mesopelagic jellyfish

    NASA Astrophysics Data System (ADS)

    Kaartvedt, Stein; Ugland, Karl I.; Klevjer, Thor A.; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-06-01

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other.

  9. Social behaviour in mesopelagic jellyfish.

    PubMed

    Kaartvedt, Stein; Ugland, Karl I; Klevjer, Thor A; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-06-11

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other.

  10. Preschool design and child behaviour.

    PubMed

    Neill, S R

    1982-07-01

    Twenty established children were observed in each of three nursery schools and two day nurseries. Two pairs of nursery schools and day nurseries were matched for building design. Twenty newly arrived children were also observed in each nursery school. Child behaviour was analysed in relation to building design; playroom openness appeared the most important building factor. Children in the more open units spent less time on school-oriented activities and received fewer staff contacts, but more time moving around, doing nothing, and in aggression and active play. Social interaction was little related to building design, but was affected by amount of nursery experience. The findings are discussed in relation to staff aims.

  11. Prodrug behaviour of nicotinoylmorphine esters.

    PubMed

    Broekkamp, C L; Oosterloo, S K; Rijk, H W

    1988-06-01

    Morphine and its nicotinoyl esters, dinicotinoylmorphine (nicomorphine), 6-mononicotinoylmorphine (6-MNM) and 3-mononicotinoylmorphine (3-MNM) were tested in mice for central activity to obtain time-effect profiles of these compounds in rats. Two effects, analgesia with the hot plate test and locomotor stimulation in activity cages were measured and nicomorphine, 6-MNM and 3-MNM were found to have a faster onset of action compared with morphine. The effects of 3-MNM and morphine lasted longer than the effect of nicomorphine and 6-MNM. The prodrug behaviour of 3-MNM and nicomorphine for morphine and 6-MNM, respectively, is discussed.

  12. Homosexuality : treatment by behaviour modification.

    PubMed

    Pradhan, P V; Ayyar, K S; Bagadia, V N

    1982-01-01

    We present here the treatment of thirteen homosexuals by behaviour modification techniques. With classical electrical aversion and positive conditioning 8(61%) out of thirteen patients showed a change in orientation lasting on a six-month 1 year follow up. A marriageable age and indirect social pressures were positively correlated with improvement whereas the presence of a steady homosexual partner and habitual passive anal intercourse indicated a poor response. The techniques, the assessments, the onset and course of improvement and complications arc discussed. Our results and techniques are compared with those of other workers.

  13. Social behaviour in mesopelagic jellyfish

    PubMed Central

    Kaartvedt, Stein; Ugland, Karl I.; Klevjer, Thor A.; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-01-01

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other. PMID:26065904

  14. Mirroring and beyond: coupled dynamics as a generalized framework for modelling social interactions.

    PubMed

    Hasson, Uri; Frith, Chris D

    2016-05-05

    When people observe one another, behavioural alignment can be detected at many levels, from the physical to the mental. Likewise, when people process the same highly complex stimulus sequences, such as films and stories, alignment is detected in the elicited brain activity. In early sensory areas, shared neural patterns are coupled to the low-level properties of the stimulus (shape, motion, volume, etc.), while in high-order brain areas, shared neural patterns are coupled to high-levels aspects of the stimulus, such as meaning. Successful social interactions require such alignments (both behavioural and neural), as communication cannot occur without shared understanding. However, we need to go beyond simple, symmetric (mirror) alignment once we start interacting. Interactions are dynamic processes, which involve continuous mutual adaptation, development of complementary behaviour and division of labour such as leader-follower roles. Here, we argue that interacting individuals are dynamically coupled rather than simply aligned. This broader framework for understanding interactions can encompass both processes by which behaviour and brain activity mirror each other (neural alignment), and situations in which behaviour and brain activity in one participant are coupled (but not mirrored) to the dynamics in the other participant. To apply these more sophisticated accounts of social interactions to the study of the underlying neural processes we need to develop new experimental paradigms and novel methods of data analysis.

  15. Mirroring and beyond: coupled dynamics as a generalized framework for modelling social interactions

    PubMed Central

    Hasson, Uri; Frith, Chris D.

    2016-01-01

    When people observe one another, behavioural alignment can be detected at many levels, from the physical to the mental. Likewise, when people process the same highly complex stimulus sequences, such as films and stories, alignment is detected in the elicited brain activity. In early sensory areas, shared neural patterns are coupled to the low-level properties of the stimulus (shape, motion, volume, etc.), while in high-order brain areas, shared neural patterns are coupled to high-levels aspects of the stimulus, such as meaning. Successful social interactions require such alignments (both behavioural and neural), as communication cannot occur without shared understanding. However, we need to go beyond simple, symmetric (mirror) alignment once we start interacting. Interactions are dynamic processes, which involve continuous mutual adaptation, development of complementary behaviour and division of labour such as leader–follower roles. Here, we argue that interacting individuals are dynamically coupled rather than simply aligned. This broader framework for understanding interactions can encompass both processes by which behaviour and brain activity mirror each other (neural alignment), and situations in which behaviour and brain activity in one participant are coupled (but not mirrored) to the dynamics in the other participant. To apply these more sophisticated accounts of social interactions to the study of the underlying neural processes we need to develop new experimental paradigms and novel methods of data analysis PMID:27069044

  16. Neural architecture of choice behaviour in a concurrent interval schedule.

    PubMed

    Kalenscher, Tobias; Diekamp, Bettina; Güntürkün, Onur

    2003-11-01

    Concurrent interval schedules are classic experimental paradigms that are traditionally employed in psychological research on choice behaviour. To analyse the neural basis of choice in a concurrent fixed interval schedule, pigeons were trained to peck on two response keys. Responses were differentially rewarded in key specific short or long time intervals (SI vs. LI). Using tetrodotoxin, we reversibly blocked the neostriatum caudolaterale (NCL, the avian functional equivalent of the prefrontal cortex), avian caudate-putamen and nucleus accumbens to examine their contribution. A detailed analysis of baseline choice behaviour revealed that response distribution and key affinity were determined by cued or time-related expectancy for rewards on the SI key. The pigeons' response frequency increased on the SI key and decreased on the LI key with increasing temporal proximity to the SI reward and pigeons switched to the LI key after reward delivery. Pecking bursts on the LI key were negatively correlated with bursts on the SI key. Neostriatum caudolaterale inactivation did not affect pecking activity per se but interfered with reward-related temporal modulation of pecking frequency, switching pattern and coupling of LI to SI pecks. Blockade of caudate-putamen resulted in a complete behavioural halt, while inactivation of nucleus accumbens diminished operant behaviour without affecting consummatory responses. These data suggest that the NCL is tuned via indirect striato-pallial projections to integrate cued or time-related reward expectancy into a response selection process in order to set, maintain or shift goals. The NCL possibly feeds forward the resulting motor commands to the caudate-putamen for execution.

  17. Sedentary behaviours during pregnancy: a systematic review.

    PubMed

    Fazzi, Caterina; Saunders, David H; Linton, Kathryn; Norman, Jane E; Reynolds, Rebecca M

    2017-03-16

    In the general population, at least 50% of time awake is spent in sedentary behaviours. Sedentary behaviours are activities that expend less energy than 1.5 metabolic equivalents, such as sitting. The amount of time spent in sedentary behaviours is a risk factor for diseases such as type 2 diabetes, cardiovascular disease, and death from all causes. Even individuals meeting physical activity guidelines are at a higher risk of premature death and adverse metabolic outcomes if they sit for extended intervals. The associations between sedentary behaviour with type 2 diabetes and with impaired glucose tolerance are stronger for women than for men. It is not known whether sedentary behaviour in pregnancy influences pregnancy outcomes, but if those negative outcomes observed in general adult population also occur in pregnancy, this could have implications for adverse outcomes for mothers and offspring. We aimed to determine the proportion of time spent in sedentary behaviours among pregnant women, and the association of sedentary behaviour with pregnancy outcomes in mothers and offspring. Two researchers independently performed the literature search using 5 different electronic bibliographic databases. Studies were included if sedentary behaviours were assessed during pregnancy. Two reviewers independently assessed the articles for quality and bias, and extracted the relevant information. We identified 26 studies meeting the inclusion criteria. Pregnant women spent more than 50% of their time in sedentary behaviours. Increased time in sedentary behaviour was significantly associated with higher levels of C Reactive Protein and LDL Cholesterol, and a larger newborn abdominal circumference. Sedentary behaviours were significantly higher among women who delivered macrosomic infants. Discrepancies were found in associations of sedentary behaviour with gestational weight gain, hypertensive disorders, and birth weight. No consistent associations were found between sedentary

  18. Fluctuations in a coupled population model

    NASA Astrophysics Data System (ADS)

    Jakeman, E.; Hopcraft, K. I.; Matthews, J. O.

    2005-07-01

    We investigate a discrete Markov process in which the immigration of individuals into one population is controlled by the fluctuations in another. We examine the effect of coupling back the second population to the first through a similar mechanism and derive exact solutions for the generating functions of the population statistics. We show that a stationary state exists over a certain parameter range and obtain expressions for moments and correlation functions in this regime. When more than two populations are coupled, cyclically transient oscillations and periodic behaviour of correlation functions are predicted. We demonstrate that if the initial distribution of either population is stable, or more generally has a power-law tail that falls off like N-(1+α) (0 < α < 1), then for certain parameter values there exists a stationary state that is also power law but not stable. This stationary state cannot be accessed from a single multiple immigrant population model, but arises solely from the nonlinear interaction of the coupled system.

  19. Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium

    SciTech Connect

    Singh Dharodi, Vikram; Kumar Tiwari, Sanat; Das, Amita

    2014-07-15

    A generalized hydrodynamic model depicting the behaviour of visco-elastic fluids has often been invoked to explore the behaviour of a strongly coupled dusty plasma medium below their crystallization limit. The model has been successful in describing the collective normal modes of the strongly coupled dusty plasma medium observed experimentally. The paper focuses on the study of nonlinear dynamical characteristic features of this model. Specifically, the evolution of coherent vorticity patches is being investigated here within the framework of this model. A comparison with Newtonian fluids and molecular dynamics simulations treating the dust species interacting through the Yukawa potential has also been presented.

  20. The integration of behaviour into comparative physiology.

    PubMed

    Gilmour, K M; Wilson, R W; Sloman, K A

    2005-01-01

    Comparative physiology has traditionally focused on the physiological responses of animals to their physicochemical environment. In recent years, awareness has increased among physiologists of the potential for behavioural factors, such as the social environment of the animal, to affect physiological condition and responses. This recognition has led to an emerging trend within the field toward using multidisciplinary approaches that incorporate both behavioural and physiological techniques. Research areas in which the integrated study of behaviour and physiology has been particularly fruitful include the physiology of the social environment, sensory physiology and behaviour, and physiological constraints on behavioural ecology. The manner in which incorporating behavioural considerations has informed the physiological data collected is discussed for each of these areas using specific examples.

  1. Social behavioural epistemology and the scientific community.

    PubMed

    Watve, Milind

    2017-07-01

    The progress of science is influenced substantially by social behaviour of and social interactions within the scientific community. Similar to innovations in primate groups, the social acceptance of an innovation depends not only upon the relevance of the innovation but also on the social dominance and connectedness of the innovator. There are a number of parallels between many well-known phenomena in behavioural evolution and various behavioural traits observed in the scientific community. It would be useful, therefore, to use principles of behavioural evolution as hypotheses to study the social behaviour of the scientific community. I argue in this paper that a systematic study of social behavioural epistemology is likely to boost the progress of science by addressing several prevalent biases and other problems in scientific communication and by facilitating appropriate acceptance/rejection of novel concepts.

  2. Nurse therapists in behavioural psychotherapy.

    PubMed Central

    Marks, I M; Hallam, R S; Philpott, R; Connolly, J C

    1975-01-01

    Five registered mental nurses (R.M.N.s) were trained over two years to become behavioural psychotherapists for adult neurotic disorders. They achieved results comparable to those obtained with similar patients and methods by psychologists and psychiatrists. Similar results were maintained when over a third year the therapists were seconded to work in four hospitals and a general practice. Patients were satisfied at being treated by nurses. After initial teething difficulties nurse therapists became valuable members of treatment teams during both training and secondment, becoming accepted by most nurses, psychologists, and psychiatrists with whom they came into contact. The training of further nurse therapists would facilitate treatment of many disabled neurotics who would otherwise go without effective treatment. Training nurse therapists takes less time and money than training psychologists and psychiatrists because less of their education is redundant to the skills involved. The pool of R.M.N.s suitable for training is much larger than that of psychiatrists and psychologists. The nurse therapists can be integrated relatively easily into treatment teams. The present nursing structure imposes restrictions on the advancement of clinical nurse specialists and a clinical tree is badly needed parallel with present administrative and teaching hierarchies. An 18-month course in adult behavioural psychotherapy has been recognized by the Joint Board of Clinical Nursing Studies for England and Wales so that nurse therapists seem destined to be a lasting feature of future treatment teams. PMID:1139262

  3. Measuring tactical behaviour in football.

    PubMed

    Sampaio, J; Maçãs, V

    2012-05-01

    The present study explored how football players' dynamic positional data can be used to assess tactical behaviour by measuring movement patterns and inter-player coordination. A pre post-test design was used to assess the effects of a 13-week constructivist and cognitivist training program by measuring behaviour in a 5 × 5 football small-sided game, played on a 60 × 40 m outdoor natural turf pitch. Data was captured at 5 Hz by GPS devices (SPI Pro, GPSports, Canberra, Australia) and analysed with non-linear signal processing methods. Approximate entropy values were lower in post-test situations suggesting that these time series became more regular with increasing expertise in football. Relative phase post-test values showed frequent periods with a clear trend to moving in anti-phase, as measured by players' distance to the centre of the team. These advances may open new research topics under the tactical scope and allow narrowing the gap between sports sciences and sports coaching. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Beliefs and behaviour in disease.

    PubMed

    Lewis, G A

    1977-01-01

    Isolated tribal communities depend on the resources available where they live and on knowledge to use them well, which is passed on by education and training in cultural skills. Anthropological studies have recorded the successful adaptations achieved in some societies. This paper discusses notions akin to those of contagion and infection as they are understood by people in a community in New Guinea. Do they show in these ideas the accurate observation and deduction apparent in their other adaptive achievements? The people have approved patterns for behaviour to maintain health and heal illness. Is the behaviour seen to be effective by them? It may not seem so to the outside medical observer but it is not rejected by the people, who must use it in coping self-reliantly with their circumstances. The question of prognosis is discussed from their point of view so as to show problems which they face in responding to opportunities of modern medical care and in judging the efficacy of treatment.

  5. Viscoelastic behaviour of pumpkin balloons

    NASA Astrophysics Data System (ADS)

    Gerngross, T.; Xu, Y.; Pellegrino, S.

    2008-11-01

    The lobes of the NASA ULDB pumpkin-shaped super-pressure balloons are made of a thin polymeric film that shows considerable time-dependent behaviour. A nonlinear viscoelastic model based on experimental measurements has been recently established for this film. This paper presents a simulation of the viscoelastic behaviour of ULDB balloons with the finite element software ABAQUS. First, the standard viscoelastic modelling capabilities available in ABAQUS are examined, but are found of limited accuracy even for the case of simple uniaxial creep tests on ULDB films. Then, a nonlinear viscoelastic constitutive model is implemented by means of a user-defined subroutine. This approach is verified by means of biaxial creep experiments on pressurized cylinders and is found to be accurate provided that the film anisotropy is also included in the model. A preliminary set of predictions for a single lobe of a ULDB is presented at the end of the paper. It indicates that time-dependent effects in a balloon structure can lead to significant stress redistribution and large increases in the transverse strains in the lobes.

  6. Genetics of human aggressive behaviour.

    PubMed

    Craig, Ian W; Halton, Kelly E

    2009-07-01

    A consideration of the evolutionary, physiological and anthropological aspects of aggression suggests that individual differences in such behaviour will have important genetic as well as environmental underpinning. Surveys of the likely pathways controlling the physiological and neuronal processes involved highlight, as obvious targets to investigate, genes implicated in sexual differentiation, anxiety, stress response and the serotonin neurotransmitter pathway. To date, however, association studies on single candidates have provided little evidence for any such loci with a major effect size. This may be because genes do not operate independently, but function against a background in which other genetic and environmental factors are crucial. Indeed, a series of recent studies, particularly concentrating on the serotonin and norepinephrine metabolising enzyme, monoamine oxidase A, has emphasised the necessity of examining gene by environmental interactions if the contributions of individual loci are to be understood. These findings will have major significance for the interpretation and analysis of data from detailed whole genome association studies. Functional imaging studies of genetic variants affecting serotonin pathways have also provided valuable insights into potential links between genes, brain and aggressive behaviour.

  7. Fracture behaviour of polycrystalline tungsten

    NASA Astrophysics Data System (ADS)

    Gaganidze, Ermile; Rupp, Daniel; Aktaa, Jarir

    2014-03-01

    Fracture behaviour of round blank polycrystalline tungsten was studied by means of three point bending Fracture-Mechanical (FM) tests at temperatures between RT and 1000 °C and under high vacuum. To study the influence of the anisotropic microstructure on the fracture toughness (FT) and ductile-to-brittle transition (DBT) the specimens were extracted in three different, i.e. longitudinal, radial and circumferential orientations. The FM tests yielded distinctive fracture behaviour for each specimen orientation. The crack propagation was predominantly intergranular for longitudinal orientation up to 600 °C, whereas transgranular cleavage was observed at low test temperatures for radial and circumferentially oriented specimens. At intermediate test temperatures the change of the fracture mode took place for radial and circumferential orientations. Above 800 °C all three specimen types showed large ductile deformation without noticeable crack advancement. For longitudinal specimens the influence of the loading rate on the FT and DBT was studied in the loading rate range between 0.06 and 18 MPa m1/2/s. Though an increase of the FT was observed for the lowest loading rate, no resolvable dependence of the DBT on the loading rate was found partly due to loss of FT validity. A Master Curve approach is proposed to describe FT vs. test temperature data on polycrystalline tungsten. Fracture safe design space was identified by analysis compiled FT data.

  8. [Instruments for evaluating behavioural disorders].

    PubMed

    Puerta, I C

    This review considers, from a theoretical clinical point of view, several interview based instruments used in the areas of neuropsychology, psychology and psychiatry that have been designed to evaluate the associated symptoms in several diagnostic categories or types in the different editions of the Diagnostic and statistical manual of mental disorders. The study of psychopathology, especially in children and adolescents, has one prior requisite: a thorough knowledge of how categorical disorders are organised by axes and the reason for the groups of symptoms and their variations located in each criterion. Consequently, in order to perform a diagnosis in child psychopathology, different criteria have to be fulfilled, according to the presence of the different disorders associated with a particular pathology, and the different evaluation tools provide a multiple approach that allows the behavioural problems to be evaluated. We currently have a series of diagnostic instruments available that are recommended for individual clinical study and can be applied both by parents and by teachers. The need then arises to research into whether the symptoms reported by parents and teachers have similar characteristics or whether, to the contrary, there are differences in the behaviour observed in distinct contexts, which would require a further analysis of the contextual particularities the patient moves in.

  9. Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour.

    PubMed

    Vogel, David; Nicolis, Stamatios C; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J T; Dussutour, Audrey

    2015-11-22

    Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: 'slow-regular-social', 'fast-regular-social' and 'fast-irregular-asocial'. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. © 2015 The Author(s).

  10. Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour

    PubMed Central

    Vogel, David; Nicolis, Stamatios C.; Perez-Escudero, Alfonso; Nanjundiah, Vidyanand; Sumpter, David J. T.; Dussutour, Audrey

    2015-01-01

    Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: ‘slow–regular–social’, ‘fast–regular–social’ and ‘fast–irregular–asocial’. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms. PMID:26609088

  11. Female perception of a partner's mate value discrepancy and controlling behaviour in romantic relationships.

    PubMed

    Danel, Dariusz P; Siennicka, Agnieszka; Glińska, Kinga; Fedurek, Piotr; Nowak-Szczepańska, Natalia; Jankowska, Ewa A; Pawłowski, Bogusław; Lewandowski, Zdzisław

    2017-01-01

    Mate value discrepancy (MVD) between heterosexual partners is an important factor influencing relationship satisfaction which, in turn, has an effect on the quality and the stability of the relationship. Therefore, partners' involvement in mate retention behaviours, such as controlling behaviours, can be related to MVD and our study aims to determine whether such an association exists. In order to do so, we analysed female perception of MVD and their opinion regarding the intensity of controlling behaviours performed by themselves as well as their romantic partners. Female perception of the intensity of controlling behaviours performed by both partners was the highest in couples where a woman assesses her own mate value (MV) as higher than her partner's MV and significantly different than in relationships where male MV exceeded those of the female. Our study also indicates that MVD should be taken into account when analysing sex differences in intensities of mate retention behaviours. Finally, we provide evidence supporting the significance of the relationship length for controlling behaviour intensity. Findings are discussed within an evolutionary perspective.

  12. Greater number of group identifications is associated with healthier behaviour: Evidence from a Scottish community sample.

    PubMed

    Sani, Fabio; Madhok, Vishnu; Norbury, Michael; Dugard, Pat; Wakefield, Juliet R H

    2015-09-01

    This paper investigates the interplay between group identification (i.e., the extent to which one has a sense of belonging to a social group, coupled with a sense of commonality with in-group members) and four types of health behaviour, namely physical exercise, smoking, drinking, and diet. Specifically, we propose a positive relationship between one's number of group identifications and healthy behaviour. This study is based on the Scottish portion of the data obtained for Wave 1 of the two-wave cross-national Health in Groups project. Totally 1,824 patients from five Scottish general practitioner (GP) surgeries completed the Wave 1 questionnaire in their homes. Participants completed measures of group identification, group contact, health behaviours, and demographic variables. Results demonstrate that the greater the number of social groups with which one identifies, the healthier one's behaviour on any of the four health dimensions considered. We believe our results are due to the fact that group identification will generally (1) enhance one's sense of meaning in life, thereby leading one to take more care of oneself, (2) increase one's sense of responsibility towards other in-group members, thereby enhancing one's motivation to be healthy in order to fulfil those responsibilities, and (3) increase compliance with healthy group behavioural norms. Taken together, these processes amply overcompensate for the fact that some groups with which people may identify can actually prescribe unhealthy behaviours. © 2014 The British Psychological Society.

  13. Plant adaptive behaviour in hydrological models (Invited)

    NASA Astrophysics Data System (ADS)

    van der Ploeg, M. J.; Teuling, R.

    2013-12-01

    Models that will be able to cope with future precipitation and evaporation regimes need a solid base that describes the essence of the processes involved [1]. Micro-behaviour in the soil-vegetation-atmosphere system may have a large impact on patterns emerging at larger scales. A complicating factor in the micro-behaviour is the constant interaction between vegetation and geology in which water plays a key role. The resilience of the coupled vegetation-soil system critically depends on its sensitivity to environmental changes. As a result of environmental changes vegetation may wither and die, but such environmental changes may also trigger gene adaptation. Constant exposure to environmental stresses, biotic or abiotic, influences plant physiology, gene adaptations, and flexibility in gene adaptation [2-6]. Gene expression as a result of different environmental conditions may profoundly impact drought responses across the same plant species. Differences in response to an environmental stress, has consequences for the way species are currently being treated in models (single plant to global scale). In particular, model parameters that control root water uptake and plant transpiration are generally assumed to be a property of the plant functional type. Assigning plant functional types does not allow for local plant adaptation to be reflected in the model parameters, nor does it allow for correlations that might exist between root parameters and soil type. Models potentially provide a means to link root water uptake and transport to large scale processes (e.g. Rosnay and Polcher 1998, Feddes et al. 2001, Jung 2010), especially when powered with an integrated hydrological, ecological and physiological base. We explore the experimental evidence from natural vegetation to formulate possible alternative modeling concepts. [1] Seibert, J. 2000. Multi-criteria calibration of a conceptual runoff model using a genetic algorithm. Hydrology and Earth System Sciences 4(2): 215

  14. [Parental Monitoring and its Relation to Behaviour Problems and Risk Behaviour in an Adolescent School Sample].

    PubMed

    Trick, Sarah; Jantzer, Vanessa; Haffner, Johann; Parzer, Peter; Resch, Franz

    2016-10-01

    Parental Monitoring and its Relation to Behaviour Problems and Risk Behaviour in an Adolescent School Sample Numerous research studies emphasize parental monitoring as a protective factor for adolescent problem behaviour. The purpose of the study presented was to use Stattin and Kerr's (2000) monitoring subscales for the first time in a German-speaking area and to explore the relations to behaviour problems in an adolescent school sample. The two active monitoring strategies "parental control" and "parental solicitation" as well as "parental knowledge" and "child disclosure" relating to behaviour problems and risk behaviour were examined. A sample of 494 pupils, grades 5, 7 and 9, of German secondary schools and their parents answered questions on "parental knowledge", "control", "solicitation" and "child disclosure". Adolescents also answered the German version of the Strengths and Difficulties Questionnaire (SDQ) and items about risk behaviour like frequency of violence, delinquency, substance abuse, self-injuring behaviour and school absenteeism. Behaviour problems in terms of the SDQ could be predicted sufficiently by "parental knowledge", but for the prediction of risk behaviour, the active parental monitoring strategies were of importance, too. More "parental knowledge", more "control" and less "solicitation" could predict less risk behaviour. Results confirm "parental knowledge" as a general protective factor for problem behaviour. However, they show the importance of "parental control" for adolescent risk behaviour.

  15. The contribution of behavioural science to primary care research: development and evaluation of behaviour change interventions.

    PubMed

    Sutton, Stephen

    2011-10-01

    Behavioural science is concerned with predicting, explaining and changing behaviour. Taking a personal perspective, this article aims to show how behavioural science can contribute to primary care research, specifically in relation to the development and evaluation of interventions to change behaviour. After discussing the definition and measurement of behaviour, the principle of compatibility and theories of behaviour change, the article outlines two examples of behaviour change trials (one on medication adherence and the other on physical activity), which were part of a research programme on prevention of chronic disease and its consequences. The examples demonstrate how, in a multidisciplinary context, behavioural science can contribute to primary care research in several important ways, including posing relevant research questions, defining the target behaviour, understanding the psychological determinants of behaviour, developing behaviour change interventions and selection or development of measures. The article concludes with a number of recommendations: (i) whether the aim is prediction, explanation or change, defining the target behaviour is a crucial first step; (ii) interventions should be explicitly based on theories that specify the factors that need to be changed in order to produce the desired change in behaviour; (iii) intervention developers need to be aware of the differences between different theories and select a theory only after careful consideration of the alternatives assessed against relevant criteria; and (iv) developers need to be aware that interventions can never be entirely theory based.

  16. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories

    PubMed Central

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-01-01

    ABSTRACT Background: Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Methods: Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. Findings: One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. Discussion: There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance. PMID:26854092

  17. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories.

    PubMed

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-09-01

    Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance.

  18. Model development for household waste prevention behaviour

    SciTech Connect

    Bortoleto, Ana Paula; Kurisu, Kiyo H.; Hanaki, Keisuke

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We model waste prevention behaviour using structure equation modelling. Black-Right-Pointing-Pointer We merge attitude-behaviour theories with wider models from environmental psychology. Black-Right-Pointing-Pointer Personal norms and perceived behaviour control are the main behaviour predictors. Black-Right-Pointing-Pointer Environmental concern, moral obligation and inconvenience are the main influence on the behaviour. Black-Right-Pointing-Pointer Waste prevention and recycling are different dimensions of waste management behaviour. - Abstract: Understanding waste prevention behaviour (WPB) could enable local governments and decision makers to design more-effective policies for reducing the amount of waste that is generated. By merging well-known attitude-behaviour theories with elements from wider models from environmental psychology, an extensive cognitive framework that provides new and valuable insights is developed for understanding the involvement of individuals in waste prevention. The results confirm the usefulness of the theory of planned behaviour and of Schwartz's altruistic behaviour model as bases for modelling participation in waste prevention. A more elaborate integrated model of prevention was shown to be necessary for the complete analysis of attitudinal aspects associated with waste prevention. A postal survey of 158 respondents provided empirical support for eight of 12 hypotheses. The proposed structural equation indicates that personal norms and perceived behaviour control are the main predictors and that, unlike the case of recycling, subjective norms have a weak influence on WPB. It also suggests that, since social norms have not presented a direct influence, WPB is likely to be influenced by a concern for the environment and the community as well by perceptions of moral obligation and inconvenience. Results also proved that recycling and waste prevention represent different dimensions of waste

  19. Interpersonal behaviour in relation to burnout.

    PubMed

    Geuens, Nina; Leemans, Annemie; Bogaerts, Annick; Van Bogaert, Peter; Franck, Erik

    2015-12-01

    Organisational and work-related challenges faced by midwives make them vulnerable to burnout, but individual factors, such as interpersonal behaviour, can also contribute. A study in eight hospitals in the Dutch-speaking part of Belgium investigated the prevalence of burnout among Flemish midwives, assessed their interpersonal behaviour, and explored the relationship between interpersonal behaviour, burnout, job satisfaction and intention to leave. This article describes the study and reports the findings.

  20. Pragmatic language impairment and associated behavioural problems.

    PubMed

    Ketelaars, Mieke P; Cuperus, Juliane; Jansonius, Kino; Verhoeven, Ludo

    2010-01-01

    Specific language impairment (SLI) is diagnosed when a child shows isolated structural language problems. The diagnosis of pragmatic language impairment (PLI) is given to children who show difficulties with the use of language in context. Unlike children with SLI, these children tend to show relatively intact structural language skills while they do exhibit clear communicative deficits. There is hardly any research on the relationship between pragmatic competence and behavioural problems. Existing research suggests a strong relationship, but has only been executed on clinical SLI samples. Moreover, it is not known whether pragmatic language problems are related to specific types of behavioural problems. This study aims to clarify the incidence and nature of behavioural problems in children with PLI using a prognostic design in mainstream education. This design should provide valuable insights into the general relationship between PLI and various behavioural problems. Teachers completed the Children's Communication Checklist (CCC) and the Strengths and Difficulties Questionnaire (SDQ) and provided additional data for a sample of 1364 children aged 4 years. Within the community sample, pragmatic competence is highly correlated with behavioural problems. Pragmatic competence is a good predictor of behavioural problems, and once pragmatic competence is accounted for, structural language abilities do not predict behavioural problems. Children with pragmatic language impairment often show behavioural problems, largely of an externalizing nature. The most prominent problems are hyperactivity and the lack of prosocial behaviour, which reach clinical levels for this group. However, all problem levels are elevated compared with normally developing children. Young children with PLI show a wide variety of behavioural problems. Early assessment of pragmatic competence may benefit early detection of children at risk of behavioural problems. Furthermore, due to the relationship

  1. Modelling robot's behaviour using finite automata

    NASA Astrophysics Data System (ADS)

    Janošek, Michal; Žáček, Jaroslav

    2017-07-01

    This paper proposes a model of a robot's behaviour described by finite automata. We split robot's knowledge into several knowledge bases which are used by the inference mechanism of the robot's expert system to make a logic deduction. Each knowledgebase is dedicated to the particular behaviour domain and the finite automaton helps us switching among these knowledge bases with the respect of actual situation. Our goal is to simplify and reduce complexity of one big knowledgebase splitting it into several pieces. The advantage of this model is that we can easily add new behaviour by adding new knowledgebase and add this behaviour into the finite automaton and define necessary states and transitions.

  2. Understanding challenging behaviour in patients with dementia.

    PubMed

    Cunningham, C

    The fifth and final article in the series on patients with dementia in acute care examines challenging behaviour. Hospital admission, combined with unfamiliar surroundings and memory problems, can be frightening and disorientating for those with dementia. This can lead to behaviour which is perceived as 'disruptive' or 'difficult'. Aspects of the hospital environment or care practice can contribute to problems that may be misinterpreted and lead to challenging behaviour. Staff should seek to understand the cause of challenging behaviour, assess the possible causes and use strategies to reinforce familiarity and minimise distress for these patients.

  3. Genetic dissection of mouse exploratory behaviour.

    PubMed

    Crusio, W E

    2001-11-01

    A large variety of apparatus and procedures are being employed to measure mouse exploratory behaviour. Definitions of what constitutes exploration also vary widely. The present article reviews two studies whose results permit a genetic dissection of behaviour displayed in an open-field situation. The results agree that factors representing exploration and stress/fear underlie this type of behaviour. Both factors appear to be linked to neuroanatomical variation in the sizes of the hippocampal intra- and infrapyramidal mossy fibre terminal fields. Multivariate analysis of genetic correlations may render important insights into the structure of behaviour and its relations with neuroanatomical and neurophysiological systems.

  4. Methods of Measurement in epidemiology: Sedentary Behaviour

    PubMed Central

    Atkin, Andrew J; Gorely, Trish; Clemes, Stacy A; Yates, Thomas; Edwardson, Charlotte; Brage, Soren; Salmon, Jo; Marshall, Simon J; Biddle, Stuart JH

    2012-01-01

    Background Research examining sedentary behaviour as a potentially independent risk factor for chronic disease morbidity and mortality has expanded rapidly in recent years. Methods We present a narrative overview of the sedentary behaviour measurement literature. Subjective and objective methods of measuring sedentary behaviour suitable for use in population-based research with children and adults are examined. The validity and reliability of each method is considered, gaps in the literature specific to each method identified and potential future directions discussed. Results To date, subjective approaches to sedentary behaviour measurement, e.g. questionnaires, have focused predominantly on TV viewing or other screen-based behaviours. Typically, such measures demonstrate moderate reliability but slight to moderate validity. Accelerometry is increasingly being used for sedentary behaviour assessments; this approach overcomes some of the limitations of subjective methods, but detection of specific postures and postural changes by this method is somewhat limited. Instruments developed specifically for the assessment of body posture have demonstrated good reliability and validity in the limited research conducted to date. Miniaturization of monitoring devices, interoperability between measurement and communication technologies and advanced analytical approaches are potential avenues for future developments in this field. Conclusions High-quality measurement is essential in all elements of sedentary behaviour epidemiology, from determining associations with health outcomes to the development and evaluation of behaviour change interventions. Sedentary behaviour measurement remains relatively under-developed, although new instruments, both objective and subjective, show considerable promise and warrant further testing. PMID:23045206

  5. Interventions for couples.

    PubMed

    Christensen, A; Heavey, C L

    1999-01-01

    A substantial body of empirical research has documented both the promise and the shortcomings of psychological interventions for preventing or ameliorating marital distress. Couple therapy reduces relationship distress and may affect individual psychopathology, such as depression. However, some couples are unresponsive and others improve but relapse later. Interventions to prevent marital distress usually produce short-term changes in behavior and relationship satisfaction, but little evidence exists demonstrating a longer-term prevention effect. Furthermore, these interventions have yet to be examined on a diverse population of couples or with a diverse set of outcome criteria (e.g. effects on children). Concern about the negative impact of marital discord and divorce will continue to provide the impetus for research on more effective means of intervening with couples. Future research could benefit from a focus on a more diverse population of couples, treatment in natural settings, the development of more powerful interventions, and the examination of those interventions over longer periods of time and with more comprehensive outcome measures.

  6. Projected coupled cluster theory

    NASA Astrophysics Data System (ADS)

    Qiu, Yiheng; Henderson, Thomas M.; Zhao, Jinmo; Scuseria, Gustavo E.

    2017-08-01

    Coupled cluster theory is the method of choice for weakly correlated systems. But in the strongly correlated regime, it faces a symmetry dilemma, where it either completely fails to describe the system or has to artificially break certain symmetries. On the other hand, projected Hartree-Fock theory captures the essential physics of many kinds of strong correlations via symmetry breaking and restoration. In this work, we combine and try to retain the merits of these two methods by applying symmetry projection to broken symmetry coupled cluster wave functions. The non-orthogonal nature of states resulting from the application of symmetry projection operators furnishes particle-hole excitations to all orders, thus creating an obstacle for the exact evaluation of overlaps. Here we provide a solution via a disentanglement framework theory that can be approximated rigorously and systematically. Results of projected coupled cluster theory are presented for molecules and the Hubbard model, showing that spin projection significantly improves unrestricted coupled cluster theory while restoring good quantum numbers. The energy of projected coupled cluster theory reduces to the unprojected one in the thermodynamic limit, albeit at a much slower rate than projected Hartree-Fock.

  7. Coupled adaptive complex networks

    NASA Astrophysics Data System (ADS)

    Shai, S.; Dobson, S.

    2013-04-01

    Adaptive networks, which combine topological evolution of the network with dynamics on the network, are ubiquitous across disciplines. Examples include technical distribution networks such as road networks and the internet, natural and biological networks, and social science networks. These networks often interact with or depend upon other networks, resulting in coupled adaptive networks. In this paper we study susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infected nodes by rewiring their intranetwork connections. However, infected nodes can pass the disease through internetwork connections, which do not change with time: The dependencies between the coupled networks remain constant. We develop an analytical formalism for these systems and validate it using extensive numerical simulation. We find that stability is increased by increasing the number of internetwork links, in the sense that the range of parameters over which both endemic and healthy states coexist (both states are reachable depending on the initial conditions) becomes smaller. Finally, we find a new stable state that does not appear in the case of a single adaptive network but only in the case of weakly coupled networks, in which the infection is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through internetwork links. We speculate on the implications of these findings.

  8. Translating teamwork behaviours from aviation to healthcare: development of behavioural markers for neonatal resuscitation.

    PubMed

    Thomas, E J; Sexton, J B; Helmreich, R L

    2004-10-01

    Improving teamwork in healthcare may help reduce and manage errors. This paper takes a step toward that goal by (1) proposing a set of teamwork behaviours, or behavioural markers, for neonatal resuscitation; (2) presenting a data form for recording observations about these markers; and (3) comparing and contrasting different sets of teamwork behaviours that have been developed for healthcare. Data from focus groups of neonatal providers, surveys, and video recordings of neonatal resuscitations were used to identify some new teamwork behaviours, to translate existing aviation team behaviours to this setting, and to develop a data collection form. This behavioural marker audit form for neonatal resuscitation lists and defines 10 markers that describe specific, observable behaviours seen during the resuscitation of newborn infants. These markers are compared with those developed by other groups. Future research should determine the relations among these behaviours and errors, and test their usefulness in measuring the impact of team training interventions.

  9. Translating teamwork behaviours from aviation to healthcare: development of behavioural markers for neonatal resuscitation

    PubMed Central

    Thomas, E; Sexton, J; Helmreich, R

    2004-01-01

    Improving teamwork in healthcare may help reduce and manage errors. This paper takes a step toward that goal by (1) proposing a set of teamwork behaviours, or behavioural markers, for neonatal resuscitation; (2) presenting a data form for recording observations about these markers; and (3) comparing and contrasting different sets of teamwork behaviours that have been developed for healthcare. Data from focus groups of neonatal providers, surveys, and video recordings of neonatal resuscitations were used to identify some new teamwork behaviours, to translate existing aviation team behaviours to this setting, and to develop a data collection form. This behavioural marker audit form for neonatal resuscitation lists and defines 10 markers that describe specific, observable behaviours seen during the resuscitation of newborn infants. These markers are compared with those developed by other groups. Future research should determine the relations among these behaviours and errors, and test their usefulness in measuring the impact of team training interventions. PMID:15465957

  10. Tube coupling device

    NASA Technical Reports Server (NTRS)

    Myers, William N. (Inventor); Hein, Leopold A. (Inventor)

    1987-01-01

    A first annular ring of a tube coupling device has a keyed opening sized to fit around the nut region of a male coupling, and a second annular ring has a keyed opening sized to fit around the nut of a female coupling. Each ring has mating ratchet teeth and these rings are biased together, thereby engaging these teeth and preventing rotation of these rings. This in turn prevents the rotation of the male nut region with respect to the female nut. For tube-to-bulkhead locking, one facet of one ring is notched, and a pin is pressed into an opening in the bulkhead. This pin is sized to fit within one of the notches in the ring, thereby preventing rotation of this ring with respect to the bulkhead.

  11. Current induced interlayer coupling

    NASA Astrophysics Data System (ADS)

    Levy, Peter M.; Heide, Carsten; Zhang, Shufeng; Fert, Albert

    2001-03-01

    It has recently been shown that a perpendicular current in a magnetically multilayered structures induces an unusual bilinear coupling between the magnetizations of the layers [1]. While this was demonstrated in the ballistic regime, transport is likely to be diffusive in the structures where this may be relevant to the role of currents in switching the magnetization of the layers. We have derived the current induced coupling by using the Boltzmann equation in terms of the parameters used to describe the giant magnetoresistance of magnetically layered structures, and thereby estimate the strength of this coupling. Work supported in part by DARPA and ONR. [1] C.Heide and R.J.Elliott, Europhys. Lett. 50, 271 (2000).

  12. Coupled nonlinear dynamical systems

    NASA Astrophysics Data System (ADS)

    Sun, Hongyan

    In this dissertation, we study coupled nonlinear dynamical systems that exhibit new types of complex behavior. We numerically and analytically examine a variety of dynamical models, ranging from systems of ordinary differential equations (ODE) with novel elements of feedback to systems of partial differential equations (PDE) that model chemical pattern formation. Chaos, dynamical uncertainty, synchronization, and spatiotemporal pattern formation constitute the primary topics of the dissertation. Following the introduction in Chapter 1, we study chaos and dynamical uncertainty in Chapter 2 with coupled Lorenz systems and demonstrate the existence of extreme complexity in high-dimensional ODE systems. In Chapter 3, we demonstrate that chaos synchronization can be achieved by mutual and multiplicative coupling of dynamical systems. Chapter 4 and 5 focus on pattern formation in reaction-diffusion systems, and we investigate segregation and integration behavior of populations in competitive and cooperative environments, respectively.

  13. Integrative Behavioral Couple Therapy.

    PubMed

    Christensen, Andrew; Doss, Brian D

    2017-02-01

    Integrative Behavioral Couple Therapy (IBCT) is based in part on traditional behavioral couple therapy but expands both the conceptualization of couple distress and of intervention. The efficacy of IBCT has been supported in three clinical trials, including one with five year follow-up. Additionally, the effectiveness of IBCT in the real world has been supported through a system-wide dissemination effort in the United States Department of Veteran's Affairs. The reach of IBCT has also been extended through an online program, www.OurRelationship.com, based on IBCT. A nationwide clinical trial with a representative sample of the US population demonstrated the effectiveness of this program on both relationship and individual variables.

  14. Saturation in coupled oscillators

    NASA Astrophysics Data System (ADS)

    Roman, Ahmed; Hanna, James

    2015-03-01

    We consider a weakly nonlinear system consisting of a resonantly forced oscillator coupled to an unforced oscillator. It has long been known that, for quadratic nonlinearities and a 2:1 resonance between the oscillators, a perturbative solution of the dynamics exhibits a phenomenon known as saturation. At low forcing, the forced oscillator responds, while the unforced oscillator is quiescent. Above a critical value of the forcing, the forced oscillator's steady-state amplitude reaches a plateau, while that of the unforced oscillator increases without bound. We show that, contrary to established folklore, saturation is not unique to quadratically nonlinear systems. We present conditions on the form of the nonlinear couplings and resonance that lead to saturation. Our results elucidate a mechanism for localization or diversion of energy in systems of coupled oscillators, and suggest new approaches for the control or suppression of vibrations in engineered systems.

  15. Comparative evaluation of effects of chemo-mechanical and conventional caries removal on dentinal morphology and its bonding characteristics - an SEM study.

    PubMed

    Arora, R; Goswami, M; Chaudhary, S; Chaitra, T R; Kishor, A; Rallan, M

    2012-08-01

    To compare the efficacy of three caries removal techniques namely: Papacarie(®), calcium hydroxide and rotary instruments by SEM analyses of the micro-morphology of residual dentine and resin tags at resin-dentine interface. 45 extracted human permanent molar teeth, with occlusal caries extending up to dentine, were divided into two groups (Group 1 and 2) and each group was subdivided into three subgroups: subgroup A included teeth treated with conventional rotary method, subgroup B and C included those treated with calcium hydroxide and Papacarie(®) respectively. Group 1 samples were prepared for viewing the micro-morphology of residual dentine (2000x and 5000x) and Group 2 samples were filled with composite resin and analysed for resin tag formation (1000x) under SEM. Papacarie(®) showed minimal smear layer and open dentinal tubules. Calcium hydroxide and rotary instruments showed a typical smear layer and occluded dentinal tubules. Resin tags obtained with Papacarie(®) were the longest and significantly superior to those obtained with rotary and calcium hydroxide. Papacarie(®) exhibited better bonding characteristics of residual dentine than calcium hydroxide and rotary method of caries removal. Thus, Papacarie(®) is a suitable alternative to conventional method of caries removal, especially in paediatric patients.

  16. An analysis in vivo of intracanal bacterial load before and after chemo-mechanical preparation: A comparative analysis of two irrigants and two activation techniques

    PubMed Central

    Rico-Romano, Cristina; Zubizarreta-Macho, Álvaro; Baquero-Artigao, María-Rosario

    2016-01-01

    Background The goals of this randomized double-blind trial were to assess the antimicrobial activity in vivo of Sodium hypochlorite (NaOCl) vs. chlorhexidine gluconate (CHX) used in combination either with EndoActivator® or IRRI S® files in patients with apical periodontitis. Material and Methods A total of 120 patients with apical periodontitis (in single or multiple root canals) were randomly assigned to the four irrigation protocols outlined below: Group A: 5.25% sodium hypochlorite (NaOCl) + EndoActivator®; Group B: 5.25% NaOCl + IRRI S® files; Group C: 2% chlorhexidine gluconate (CHX) + EndoActivator®; Group D: 2% CHX + IRRI S® files. Paper points were used to collect microbiological samples before (1A samples) and after (1B samples) irrigation. Viable colony-forming units (CFU) were quantified twice: (1) without speciation, and (2) only for Enterococcus Faecalis(EF). Statistical analysis was performed using SPSS 22.0 for Windows. Results No significant differences were observed between NaOCl and CHX in the reduction of CFU; in fact, reduction was < 93% for the two irrigants. Conversely, statistically significant differences were found between the two activation techniques (sonic and ultrasonic) in the reduction of Enterococcus Faecalis(EF). Thus, the effectiveness of ultrasonic activation was significantly higher (< 93%; p=0.012) as compared to sonic activation. Following the combination of the two irrigants with the two activation techniques (groups A, B, C and D), significant differences were observed between group A and B (p=0.025) in the reduction of EF populations, reaching up to 94%. Conclusions NaClO and CHX are effective in reducing intracanal bacterial load. Ultrasonic activation is the most effective activation technique in reducing EF populations. Key words:Chlorhexidine gluconate, sodium hypochlorite, ultrasonic irrigation, sonic irrigation, apical periodontitis, Enterococcus faecalis. PMID:26855714

  17. Stochastic Coupled Cluster Theory

    NASA Astrophysics Data System (ADS)

    Thom, Alex J. W.

    2010-12-01

    We describe a stochastic coupled cluster theory which represents excitation amplitudes as discrete excitors in the space of excitation amplitudes. Reexpressing the coupled cluster (CC) equations as the dynamics of excitors in this space, we show that a simple set of rules suffices to evolve a distribution of excitors to sample the CC solution and correctly evaluate the CC energy. These rules are not truncation specific and this method can calculate CC solutions to an arbitrary level of truncation. We present results of calculation on the neon atom, and nitrogen and water molecules showing the ability to recover both truncated and full CC results.

  18. Actively coupled optical waveguides

    NASA Astrophysics Data System (ADS)

    Alexeeva, N. V.; Barashenkov, I. V.; Rayanov, K.; Flach, S.

    2014-01-01

    We consider light propagation through a pair of nonlinear optical waveguides with absorption, placed in a medium with power gain. The active medium boosts the in-phase component of the overlapping evanescent fields of the guides, while the nonlinearity of the guides couples it to the damped out-of-phase component creating a feedback loop. As a result, the structure exhibits stable stationary and oscillatory regimes in a wide range of gain-loss ratios. We show that the pair of actively coupled (AC) waveguides can act as a stationary or integrate-and-fire comparator sensitive to tiny differences in their input powers.

  19. Effects of laboratory colonization on Bactrocera dorsalis (Diptera, Tephritidae) mating behaviour: ‘what a difference a year makes’

    PubMed Central

    Schutze, Mark K.; Dammalage, Thilak; Jessup, Andrew; Vreysen, Marc J.B.; Wornoayporn, Viwat; Clarke, Anthony R.

    2015-01-01

    Abstract Laboratory-reared insects are widely known to have significantly reduced genetic diversity in comparison to wild populations; however, subtle behavioural changes between laboratory-adapted and wild or ‘wildish’ (i.e., within one or very few generations of field collected material) populations are less well understood. Quantifying alterations in behaviour, particularly sexual, in laboratory-adapted insects is important for mass-reared insects for use in pest management strategies, especially those that have a sterile insect technique component. We report subtle changes in sexual behaviour between ‘wildish’ Bactrocera dorsalis flies (F1 and F2) from central and southern Thailand and the same colonies 12 months later when at six generations from wild. Mating compatibility tests were undertaken under standardised semi-natural conditions, with number of homo/heterotypic couples and mating location in field cages analysed via compatibility indices. Central and southern populations of Bactrocera dorsalis displayed positive assortative mating in the 2010 trials but mated randomly in the 2011 trials. ‘Wildish’ southern Thailand males mated significantly earlier than central Thailand males in 2010; this difference was considerably reduced in 2011, yet homotypic couples from southern Thailand still formed significantly earlier than all other couple combinations. There was no significant difference in couple location in 2010; however, couple location significantly differed among pair types in 2011 with those involving southern Thailand females occurring significantly more often on the tree relative to those with central Thailand females. Relative participation also changed with time, with more southern Thailand females forming couples relative to central Thailand females in 2010; this difference was considerably decreased by 2011. These results reveal how subtle changes in sexual behaviour, as driven by laboratory rearing conditions, may significantly

  20. Sexual behaviour in context: a global perspective.

    PubMed

    Wellings, Kaye; Collumbien, Martine; Slaymaker, Emma; Singh, Susheela; Hodges, Zoé; Patel, Dhaval; Bajos, Nathalie

    2006-11-11

    Research aimed at investigating sexual behaviour and assessing interventions to improve sexual health has increased in recent decades. The resulting data, despite regional differences in quantity and quality, provide a historically unique opportunity to describe patterns of sexual behaviour and their implications for attempts to protect sexual health at the beginning of the 21st century. In this paper we present original analyses of sexual behaviour data from 59 countries for which they were available. The data show substantial diversity in sexual behaviour by region and sex. No universal trend towards earlier sexual intercourse has occurred, but the shift towards later marriage in most countries has led to an increase in premarital sex, the prevalence of which is generally higher in developed countries than in developing countries, and is higher in men than in women. Monogamy is the dominant pattern everywhere, but having had two or more sexual partners in the past year is more common in men than in women, and reported rates are higher in industrialised than in non-industrialised countries. Condom use has increased in prevalence almost everywhere, but rates remain low in many developing countries. The huge regional variation indicates mainly social and economic determinants of sexual behaviour, which have implications for intervention. Although individual behaviour change is central to improving sexual health, efforts are also needed to address the broader determinants of sexual behaviour, particularly those that relate to the social context. The evidence from behavioural interventions is that no general approach to sexual-health promotion will work everywhere and no single-component intervention will work anywhere. Comprehensive behavioural interventions are needed that take account of the social context in mounting individual-level programmes, attempt to modify social norms to support uptake and maintenance of behaviour change, and tackle the structural factors

  1. The Home and Community Social Behaviour Scales (HCBS): Dimensionality in Social Competence and Antisocial Behaviours

    ERIC Educational Resources Information Center

    Hukkelberg, Silje; Ogden, Terje

    2016-01-01

    The study investigated dimensionality in the Home and Community Social Behaviour Scales (HCSBS) that assess social competence (Peer Relations and Self-Management/Compliance) and antisocial behaviour (Defiant/Disruptive and Antisocial/Aggressive behaviour) in children and adolescents. The four scales comprising 64 items were completed by 551…

  2. Whole School Behaviour Management and Perceptions of Behaviour Problems in Australian Primary Schools

    ERIC Educational Resources Information Center

    De Nobile, John; London, Teola; El Baba, Mariam

    2015-01-01

    Over the past decade and a half, whole school behaviour management systems have been implemented in many Australian schools in efforts to reduce undesirable behaviours and improve outcomes for students with behaviour problems. There is evidence in the literature suggesting that whole school approaches are more effective at managing student…

  3. The Efficacy of Positive Behavioural Support with the Most Challenging Behaviour: The Evidence and Its Implications

    ERIC Educational Resources Information Center

    LaVigna, Gary W.; Willis, Thomas J.

    2012-01-01

    Background: Positive behaviour support (PBS) is behaviour analysis applied in support of people with challenging behaviour. Questions have been raised as to PBS effectiveness, costs, and accessibility. Method: Outcome studies meeting specified criteria for PBS were selected for review. All told, 12 outcome studies encompassing 423 cases were…

  4. Closing the intention-behaviour gap for sunscreen use and sun protection behaviours.

    PubMed

    Allom, Vanessa; Mullan, Barbara; Sebastian, Jamie

    2013-01-01

    Two studies were conducted with the aim of closing the intention-behaviour gap for sunscreen use and sun protection behaviours by examining the influence of self-regulatory capacity on the prediction of sunscreen use (Study 1) and self-regulatory capacity and habit on sun protection behaviours (Study 2). Studies were conducted online. Participants completed questionnaires and cognitive measures and then reported behaviour one week later. Questionnaires measuring intention and cognitive tasks measuring self-regulatory capacity were administered to 209 university students. One week later, participants reported behaviour. In Study 2, questionnaires measuring intentions, and habit and cognitive tasks measuring self-regulatory capacity were administered to 178 university students who reported behaviour one week later. Intention accounted for 7.1% of variance in sunscreen use, no measures of self-regulation accounted for variance in behaviour or moderated the intention-behaviour gap (Study 1). Intention, self-regulatory capacity and habit accounted for 56.1% of variance in sun protection behaviours (Study 2). Intention, self-regulatory ability and habit predicted behaviour, while habit moderated the intention-behaviour gap. Interventions aimed at increasing sun protection behaviours should take into account level of intention, self-regulatory capacity and habit. Individuals may benefit from habit formation strategies and self-regulation training.

  5. The Home and Community Social Behaviour Scales (HCBS): Dimensionality in Social Competence and Antisocial Behaviours

    ERIC Educational Resources Information Center

    Hukkelberg, Silje; Ogden, Terje

    2016-01-01

    The study investigated dimensionality in the Home and Community Social Behaviour Scales (HCSBS) that assess social competence (Peer Relations and Self-Management/Compliance) and antisocial behaviour (Defiant/Disruptive and Antisocial/Aggressive behaviour) in children and adolescents. The four scales comprising 64 items were completed by 551…

  6. Whole School Behaviour Management and Perceptions of Behaviour Problems in Australian Primary Schools

    ERIC Educational Resources Information Center

    De Nobile, John; London, Teola; El Baba, Mariam

    2015-01-01

    Over the past decade and a half, whole school behaviour management systems have been implemented in many Australian schools in efforts to reduce undesirable behaviours and improve outcomes for students with behaviour problems. There is evidence in the literature suggesting that whole school approaches are more effective at managing student…

  7. Testing the bi-dimensional effects of attitudes on behavioural intentions and subsequent behaviour.

    PubMed

    Elliott, Mark A; Brewster, Sarah E; Thomson, James A; Malcolm, Carly; Rasmussen, Susan

    2015-11-01

    Attitudes are typically treated as unidimensional predictors of both behavioural intentions and subsequent behaviour. On the basis of previous research showing that attitudes comprise two independent, positive and negative dimensions, we hypothesized that attitudes would be bi-dimensional predictors of both behavioural intentions and subsequent behaviour. We focused on health-risk behaviours. We therefore also hypothesized that the positive dimension of attitude (evaluations of positive behavioural outcomes) would better predict both behavioural intentions and subsequent behaviour than would the negative dimension, consistent with the positivity bias/offset principle. In Study 1 (cross sectional design), N = 109 university students completed questionnaire measures of their intentions to binge-drink and the positive and negative dimensions of attitude. Consistent with the hypotheses, both attitude dimensions independently predicted behavioural intentions and the positive dimension was a significantly better predictor than was the negative dimension. The same pattern of findings emerged in Study 2 (cross sectional design; N = 186 university students) when we predicted intentions to binge-drink, smoke and consume a high-fat diet. Similarly, in Study 3 (prospective design; N = 1,232 speed limit offenders), both the positive and negative dimensions of attitude predicted subsequent (6-month post-baseline) speeding behaviour on two different road types and the positive dimension was the better predictor. The implications for understanding the motivation of behaviour and the development of behaviour-change interventions are discussed. © 2014 The British Psychological Society.

  8. On contextuality in behavioural data.

    PubMed

    Dzhafarov, Ehtibar N; Kujala, Janne V; Cervantes, Víctor H; Zhang, Ru; Jones, Matt

    2016-05-28

    Dzhafarovet al.(Dzhafarovet al.2016Phil. Trans. R. Soc. A374, 20150099. (doi:10.1098/rsta.2015.0099)) reviewed several behavioural datasets imitating the formal design of the quantum-mechanical contextuality experiments. The conclusion was that none of these datasets exhibited contextuality if understood in the generalized sense proposed by Dzhafarovet al.(2015Found. Phys.7, 762-782. (doi:10.1007/s10701-015-9882-9)), while the traditional definition of contextuality does not apply to these data because they violate the condition of consistent connectedness (also known as marginal selectivity, no-signalling condition, no-disturbance principle, etc.). In this paper, we clarify the relationship between (in)consistent connectedness and (non)contextuality, as well as between the traditional and extended definitions of (non)contextuality, using as an example the Clauser-Horn-Shimony-Holt inequalities originally designed for detecting contextuality in entangled particles. © 2016 The Author(s).

  9. Coordinated Behaviour in Pigeon Flocks

    PubMed Central

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Vásárhelyi, Gábor; Nagy, Máté

    2015-01-01

    We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns. PMID:26485662

  10. Tribological Behaviour of Kfre Composite

    NASA Astrophysics Data System (ADS)

    Chin, C. W.; Yousif, B. F.

    This paper presents an attempt to use kenaf fibres as reinforcement for tribo-polymeric composite. Kenaf fibres reinforced epoxy (KFRE) composite was fabricated using a closed mould technique associated with vacuum system. Adhesive wear and frictional behaviour of the composite and neat epoxy (NE) were studied against polished stainless steel counterface using a newly developed block-on-disc (BOD) machine at 50N applied load, sliding distances (0-4.2 km) and sliding velocities of 2.8 m/s. The morphology of the worn surfaces of the composite and NE was studied using a scanning electron microscope (SEM). The result revealed that the longer the sliding distance is, the higher the weight loss. Up to 70% reduction in the weight loss was achieved when the epoxy was reinforced with the kenaf fibres. The wear mechanism was predominated by plastic deformation, in the resinous regions and debonding of fibres.

  11. Information sharing promotes prosocial behaviour

    NASA Astrophysics Data System (ADS)

    Szolnoki, Attila; Perc, Matjaž

    2013-05-01

    More often than not, bad decisions are bad regardless of where and when they are made. Information sharing might thus be utilized to mitigate them. Here we show that sharing information about strategy choice between players residing on two different networks reinforces the evolution of cooperation. In evolutionary games, the strategy reflects the action of each individual that warrants the highest utility in a competitive setting. We therefore assume that identical strategies on the two networks reinforce themselves by lessening their propensity to change. Besides network reciprocity working in favour of cooperation on each individual network, we observe the spontaneous emergence of correlated behaviour between the two networks, which further deters defection. If information is shared not just between individuals but also between groups, the positive effect is even stronger, and this despite the fact that information sharing is implemented without any assumptions with regard to content.

  12. Coordinated Behaviour in Pigeon Flocks.

    PubMed

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Vásárhelyi, Gábor; Nagy, Máté

    2015-01-01

    We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns.

  13. Restrictive dermopathy and fetal behaviour.

    PubMed

    Mulder, E J; Beemer, F A; Stoutenbeek, P

    2001-07-01

    We report three siblings from consecutive pregnancies affected with restrictive dermopathy (RD). During the second pregnancy, fetal behavioural development and growth were studied extensively using ultrasound at 1-4 week intervals. Dramatic and sudden changes occurred in fetal body movements and growth but not until the end of the second trimester of pregnancy. Prominent at that time were prolonged periods of fetal quiescence and very low heart rate variability, together with abnormally executed body movements of short duration. Retarded femoral development and jerky abrupt fetal body movements (abnormal movement quality) were already present in the early second trimester of pregnancy. Facial anomalies emerged despite the presence of fetal mouth movements. The clinical features of RD were only partly explained by present knowledge of skin development and the fetal akinesia deformation sequence hypothesis. Quantitative assessment of fetal movements proved to be a poor early marker for antenatal diagnosis of this disorder.

  14. The coupled nonlinear dynamics of a lift system

    SciTech Connect

    Crespo, Rafael Sánchez E-mail: stefan.kaczmarczyk@northampton.ac.uk E-mail: huijuan.su@northampton.ac.uk; Kaczmarczyk, Stefan E-mail: stefan.kaczmarczyk@northampton.ac.uk E-mail: huijuan.su@northampton.ac.uk; Picton, Phil E-mail: stefan.kaczmarczyk@northampton.ac.uk E-mail: huijuan.su@northampton.ac.uk; Su, Huijuan E-mail: stefan.kaczmarczyk@northampton.ac.uk E-mail: huijuan.su@northampton.ac.uk

    2014-12-10

    Coupled lateral and longitudinal vibrations of suspension and compensating ropes in a high-rise lift system are often induced by the building motions due to wind or seismic excitations. When the frequencies of the building become near the natural frequencies of the ropes, large resonance motions of the system may result. This leads to adverse coupled dynamic phenomena involving nonplanar motions of the ropes, impact loads between the ropes and the shaft walls, as well as vertical vibrations of the car, counterweight and compensating sheave. Such an adverse dynamic behaviour of the system endangers the safety of the installation. This paper presents two mathematical models describing the nonlinear responses of a suspension/ compensating rope system coupled with the elevator car / compensating sheave motions. The models accommodate the nonlinear couplings between the lateral and longitudinal modes, with and without longitudinal inertia of the ropes. The partial differential nonlinear equations of motion are derived using Hamilton Principle. Then, the Galerkin method is used to discretise the equations of motion and to develop a nonlinear ordinary differential equation model. Approximate numerical solutions are determined and the behaviour of the system is analysed.

  15. Antiferromagnetic coupling in soft amorphous ferromagnet/semiconductor multilayers

    NASA Astrophysics Data System (ADS)

    Velez, Maria

    2005-03-01

    Antiferromagnetic coupling between ferromagnetic layers separated by nonmagnetic metallic interlayers has been intensively studied due to the fundamental and technological interest in such behaviour. In this work, the presence of antiferromagnetic (AF) coupling has been investigated in multilayers where the nonmagnetic interlayers are not metallic but semiconducting. The analyzed samples are amorphous (CoxSi1-x)5 nm /(Si)d multilayers obtained by co-sputtering on Si substrates, and the Si layer thickness has been varied in the range 1 nm < d < 15 nm. X-ray diffraction analysis has shown that the multilayered structure is well defined. The individual (CoxSi1-x)5 nm ferromagnetic layer presents an uniaxial anisotropy and a soft magnetic behaviour (with coercivity smaller than 1 Oe for fields applied along its easy axis), being suitable to detect the possible AF coupling in the multilayer. Magneto-optical kerr effect and alternating gradient magnetometry measurements have revealed that these multilayers do present AF coupling at room temperature for d < 8 nm. Moreover, the magnetic field required to switch between antiparallel and parallel configurations is as low as 3 Oe and varies slightly with the Si layer thickness [1]. [1] C. Quiros et al., Phys. Rev. B (in press)

  16. Is Stratosphere-Troposphere Coupling Linear?

    NASA Astrophysics Data System (ADS)

    Hitchcock, Peter; Haynes, Peter

    2013-04-01

    On first glance, the 'dripping paint' figure of Baldwin and Dunkerton suggests that the influence of Arctic stratospheric variability on the tropospheric jets is linear: weak vortex events tend to drive the jets equatorwards while strong vortex events drive them polewards. If one views stratospheric dynamics as a competition between radiative cooling and dynamical heating--processes with a large time-scale separation--this apparent linearity is surprising. On the other hand, if one views the influence of the stratosphere as an `external forcing' on the tropospheric jets, the linearity might be expected. In addition to being of fundamental dynamical interest, this issue has an important bearing on the interpretation of commonly applied diagnostic tools. The linearity of the coupling will be discussed in detail, and evidence for threshold-type behaviour will be presented.

  17. On a strong coupling property of QCD

    NASA Astrophysics Data System (ADS)

    Grandou, T.

    2017-03-01

    The fermionic Green's functions of QCD exhibit an unexpected property of effective locality, which appears to be exact, involving no approximation. In the limit of strong coupling, and at eikonal and quenching approximations (where this property was first discovered), effective locality implies a dependence of non-perturbative fermionic Green's functions on the full algebraic content of the rank 2-SUc(3) color algebra. At variance with Perturbation Theory and a variety of non-perturbative approaches also, C3-dependences show up, where C3 stands for the second, trilinear Casimir invariant of SUc(3). These dependences are sub-leading in magnitude and seem to comply with the maximally allowed departures from the pure C2 behaviours advocated by lattice numerical estimates.

  18. Distressed Couples and Marriage Education

    ERIC Educational Resources Information Center

    DeMaria, Rita M.

    2005-01-01

    Professionals generally believe that couples who choose to attend marriage education programs are not as distressed as are clinical couples and that distressed couples are not good candidates for marriage education. We examined these assumptions in 129 married couples who enrolled in a PAIRS, Practical Application of Intimate Relationship Skills…

  19. Inverse analysis and robustness evaluation for biological structure behaviour in FE simulation: application to the liver.

    PubMed

    Conte, Cécile; Masson, Catherine; Arnoux, Pierre-Jean

    2012-01-01

    To prevent traumas to abdominal organs, the selection of efficient safety devices should be based on a detailed knowledge of injury mechanisms and related injury criteria. In this sense, finite element (FE) simulation coupled with experiment could be a valuable tool to provide a better understanding of the behaviour of internal organs under crash conditions. This work proposes a methodology based on inverse analysis which combines exploration process optimisation and robustness study to obtain mechanical behaviour of the complex structure of the liver through FE simulation. The liver characterisation was based on Mooney-Rivlin hyperelastic behaviour law considering whole liver structure under uniform quasi-static compression. With the global method used, the model fits experimental data. The variability induced by modelling parameters is quantified within a reasonable time.

  20. Feeding behaviour of Black Sea bottom fishes: Did it change over time?

    NASA Astrophysics Data System (ADS)

    Bănaru, Daniela; Harmelin-Vivien, Mireille

    2009-11-01

    This study was designed to improve knowledge in feeding behaviour of the round goby ( Apollonia melanostomus (Pallas, 1814)), the red mullet ( Mullus barbatus ponticus Essipov, 1927), the whiting ( Merlangius merlangus (Linnaeus, 1758)), the flounder ( Platichthys flesus (Linnaeus, 1758)), the sole ( Solea solea (Linnaeus, 1758)), the turbot ( Psetta maeotica (Pallas, 1814)) and the starry sturgeon ( Acipenser stellatus Pallas, 1771) from the north-western Black Sea. Gut content coupled with stable isotope analysis allowed describing food web variations according to species, in two seasons and at two areas located seawards the Danube River. Present results showed that most fishes have likely changed their feeding behaviour compared to past studies from the same area. Trophic niches were reduced and dietary overlap was common, as different fish species consumed the same dominant prey types. Fishes probably adapted their feeding behaviour to the increasingly low biodiversity of the Black Sea communities.

  1. Modelling Viscoelastic Behaviour of Polymer by A Mixed Velocity, Displacement Formulation - Numerical and Experimental Results

    SciTech Connect

    Pham, VT.; Silva, L.; Digonnet, H.; Combeaud, C.; Billon, N.; Coupez, T.

    2011-05-04

    The objective of this work is to model the viscoelastic behaviour of polymer from the solid state to the liquid state. With this objective, we perform experimental tensile tests and compare with simulation results. The chosen polymer is a PMMA whose behaviour depends on its temperature. The computation simulation is based on Navier-Stokes equations where we propose a mixed finite element method with an interpolation P1+/P1 using displacement (or velocity) and pressure as principal variables. The implemented technique uses a mesh composed of triangles (2D) or tetrahedra (3D). The goal of this approach is to model the viscoelastic behaviour of polymers through a fluid-structure coupling technique with a multiphase approach.

  2. Parental Communication and Youth Sexual Behaviour

    ERIC Educational Resources Information Center

    Aspy, Cheryl B.; Vesely, Sara K.; Oman, Roy F.; Rodine, Sharon; Marshall, LaDonna; McLeroy, Ken

    2007-01-01

    The role of parental communication and instruction concerning sexual behaviour were studied in a community-based sample of 1083 youth aged 13-17 (mean age of 15 years; 51% girls, 49% White). The Youth Asset Survey was administered along with items measuring demographics and youth risk behaviours. After controlling for demographic factors,…

  3. Behaviour and school performance after brain injury.

    PubMed

    Hawley, Carol A

    2004-07-01

    To examine the relationship between behavioural problems and school performance following traumatic brain injury (TBI). 67 school-age children with TBI (35 mild, 13 moderate, 19 severe) and 14 uninjured matched controls. Parents and children were interviewed at a mean of 2 years post-TBI. Teachers reported on academic performance and educational needs. Children were assessed using the Vineland Adaptive Behaviour Scales (VABS) and the Weschler Intelligence Scale for Children (WISC-III). Two-thirds of children with TBI exhibited significant behavioural problems, significantly more than controls (p = 0.02). Children with behavioural problems had a mean IQ aproximately 15 points lower than those without (p = 0.001, 95% CI: 7-26.7). At school, 76%(19) of children with behavioural problems also had difficulties with schoolwork. Behavioural problems were associated with social deprivation and parental marital status (p < or = 0.01). Children with TBI are at risk of developing behavioural problems which may affect school performance. Children with TBI should be screened to identify significant behavioural problems before they return to school.

  4. When population and evolutionary genetics met behaviour.

    PubMed

    Costa, Rodolfo; Stanewsky, Ralf

    2013-01-01

    In this review, we analyse the impact of a population and evolutionary genetics approach on the study of insect behaviour. Our attention is focused on the model organism Drosophila melanogaster and several other insect species. In particular, we explore the relationship between rhythmic behaviours and the molecular evolution of clock and ion channel genes.

  5. Behavioural activation: history, evidence and promise.

    PubMed

    Kanter, Jonathan W; Puspitasari, Ajeng J; Santos, Maria M; Nagy, Gabriela A

    2012-05-01

    Behavioural activation holds promise to reduce the global burden of depression as a treatment approach that is effective, easy to teach, scalable and acceptable to providers and patients across settings and cultures. This editorial reviews the history of behavioural activation, what it is, current evidence for its use and future directions.

  6. Identifying Successful Learners from Interaction Behaviour

    ERIC Educational Resources Information Center

    McCuaig, Judi; Baldwin, Julia

    2012-01-01

    The interaction behaviours of successful, high-achieving learners when using a Learning Management System (LMS) are different than the behaviours of learners who are having more difficulty mastering the course material. This paper explores the idea that conventional Learning Management Systems can exploit data mining techniques to predict the…

  7. Identifying Russian and Finnish Adolescents' Problem Behaviours

    ERIC Educational Resources Information Center

    Kemppainen, Ulla; Tossavainen, Kerttu; Vartiainen, Erkki; Puska, Pekka; Jokela, Veikko; Pantelejev, Vladimir; Uhanov, Mihail

    2007-01-01

    Purpose: The purpose of the paper is to show that a syndrome of problem behaviours, i.e. early substance abuse, school and family problems and sexual promiscuity impairs normal development in adolescence. This comparative study looked for differences in the problem behaviour profiles of 15-year-old adolescents in the Pitkaranta district in Russia…

  8. The Behavioural Phenotype of Angelman Syndrome

    ERIC Educational Resources Information Center

    Horsler, K.; Oliver, C.

    2006-01-01

    Background: The purpose of this review is to examine the notion of a behavioural phenotype for Angelman syndrome and identify methodological and conceptual influences on the accepted presentation. Methods: Studies examining the behavioural characteristics associated with Angelman syndrome are reviewed and methodology is described. Results:…

  9. Students' Behavioural Intentions towards Peers with Disability

    ERIC Educational Resources Information Center

    Brown, Hilary K.; Ouellette-Kuntz, Helene; Lysaght, Rosemary; Burge, Philip

    2011-01-01

    Background: The objectives of this study were: (i) to compare the behavioural intentions of high school students towards individuals with intellectual disabilities and individuals with physical disabilities and (ii) to explore reasons for these behavioural intentions. Materials and methods: A sample of 319 Grade 9 and Grade 12 students in Ontario,…

  10. Behavioural Approaches to Understanding Student Choice

    ERIC Educational Resources Information Center

    Diamond, Abigail; Vorley, Tim; Roberts, Jennifer; Jones, Stephen

    2012-01-01

    The Higher Education Academy (HEA), in partnership with the National Union of Students (NUS), commissioned CFE and The University of Sheffield to undertake research to explore behavioural approaches to understanding student choice. Within the research, the authors' applied insights from behavioural economics to help aid understanding of student…

  11. Effective Intervention for School Refusal Behaviour

    ERIC Educational Resources Information Center

    Nuttall, Clare; Woods, Kevin

    2013-01-01

    Evaluation of successful professional intervention for two case studies of female adolescents' school refusal behaviour is presented. Data gathered from the young person, professionals, and parents in each case are synthesised to propose a multi-level, ecologically situated model of intervention for school refusal behaviour. The proposed model…

  12. Information Searching Behaviour of Young Slovenian Researchers

    ERIC Educational Resources Information Center

    Vilar, Polona; Zumer, Maja

    2011-01-01

    Purpose: The purpose of this paper is to present the findings of an empirical study of information behaviour of young Slovenian researchers. Design/methodology/approach: Built on some well-known models of scholarly information behaviour the study complements a previously conducted study of the same population, which focused on the aspects of user…

  13. The Behavioural Phenotype of Angelman Syndrome

    ERIC Educational Resources Information Center

    Horsler, K.; Oliver, C.

    2006-01-01

    Background: The purpose of this review is to examine the notion of a behavioural phenotype for Angelman syndrome and identify methodological and conceptual influences on the accepted presentation. Methods: Studies examining the behavioural characteristics associated with Angelman syndrome are reviewed and methodology is described. Results:…

  14. Evolutionary accounts of human behavioural diversity

    PubMed Central

    Brown, Gillian R.; Dickins, Thomas E.; Sear, Rebecca; Laland, Kevin N.

    2011-01-01

    Human beings persist in an extraordinary range of ecological settings, in the process exhibiting enormous behavioural diversity, both within and between populations. People vary in their social, mating and parental behaviour and have diverse and elaborate beliefs, traditions, norms and institutions. The aim of this theme issue is to ask whether, and how, evolutionary theory can help us to understand this diversity. In this introductory article, we provide a background to the debate surrounding how best to understand behavioural diversity using evolutionary models of human behaviour. In particular, we examine how diversity has been viewed by the main subdisciplines within the human evolutionary behavioural sciences, focusing in particular on the human behavioural ecology, evolutionary psychology and cultural evolution approaches. In addition to differences in focus and methodology, these subdisciplines have traditionally varied in the emphasis placed on human universals, ecological factors and socially learned behaviour, and on how they have addressed the issue of genetic variation. We reaffirm that evolutionary theory provides an essential framework for understanding behavioural diversity within and between human populations, but argue that greater integration between the subfields is critical to developing a satisfactory understanding of diversity. PMID:21199836

  15. Parental Communication and Youth Sexual Behaviour

    ERIC Educational Resources Information Center

    Aspy, Cheryl B.; Vesely, Sara K.; Oman, Roy F.; Rodine, Sharon; Marshall, LaDonna; McLeroy, Ken

    2007-01-01

    The role of parental communication and instruction concerning sexual behaviour were studied in a community-based sample of 1083 youth aged 13-17 (mean age of 15 years; 51% girls, 49% White). The Youth Asset Survey was administered along with items measuring demographics and youth risk behaviours. After controlling for demographic factors,…

  16. Identifying Russian and Finnish Adolescents' Problem Behaviours

    ERIC Educational Resources Information Center

    Kemppainen, Ulla; Tossavainen, Kerttu; Vartiainen, Erkki; Puska, Pekka; Jokela, Veikko; Pantelejev, Vladimir; Uhanov, Mihail

    2007-01-01

    Purpose: The purpose of the paper is to show that a syndrome of problem behaviours, i.e. early substance abuse, school and family problems and sexual promiscuity impairs normal development in adolescence. This comparative study looked for differences in the problem behaviour profiles of 15-year-old adolescents in the Pitkaranta district in Russia…

  17. Evidence-Based Classroom Behaviour Management Strategies

    ERIC Educational Resources Information Center

    Parsonson, Barry S.

    2012-01-01

    This paper reviews a range of evidence-based strategies for application by teachers to reduce disruptive and challenging behaviours in their classrooms. These include a number of antecedent strategies intended to help minimise the emergence of problematic behaviours and a range of those which provide positive consequences for appropriate student…

  18. The Construction of Emotional and Behavioural Difficulties

    ERIC Educational Resources Information Center

    Jones, Raya A.

    2003-01-01

    This paper presents a critique of the educational model of emotional and behavioural difficulties in British education. In the wake of strong criticisms of the so-called medical model of maladjustment (pre-1980s), educational policies have defined the "disturbing" pupil as having emotional and behavioural difficulties, and have more…

  19. Mobbing Behaviour: Victims and the Affected

    ERIC Educational Resources Information Center

    Erturk, Abbas

    2013-01-01

    The purpose of this research was to identify the level of mobbing behaviour faced by teachers and managers working in primary schools, their responses to such behaviour and the difference in these responses according to the gender variable. The sample of the research consists of a total of 1,316 teachers and managers including 691 men and 625…

  20. Health-Promoting Behaviours in Conservatoire Students

    ERIC Educational Resources Information Center

    Kreutz, Gunter; Ginsborg, Jane; Williamon, Aaron

    2009-01-01

    This study focuses on health-promoting behaviours in students from two conservatoires, the Royal Northern College of Music (RNCM, Manchester, UK; n =199) and the Royal College of Music (RCM, London, UK; n = 74). The research questions concern (a) the levels and types of health-promoting behaviours among performance students and (b) the association…

  1. Effective Intervention for School Refusal Behaviour

    ERIC Educational Resources Information Center

    Nuttall, Clare; Woods, Kevin

    2013-01-01

    Evaluation of successful professional intervention for two case studies of female adolescents' school refusal behaviour is presented. Data gathered from the young person, professionals, and parents in each case are synthesised to propose a multi-level, ecologically situated model of intervention for school refusal behaviour. The proposed model…

  2. [Language Competence and Behavioural Problems in Preschool].

    PubMed

    Rißling, J K; Melzer, J; Menke, B; Petermann, F; Daseking, M

    2015-10-01

    Children with language disorders are at increased risk of developing behavioural and emotional problems. The analysis focused on the question whether behavioural problems differ depending on the type of language deficit. The present study examines the behaviour of preschool children with different language impairments. The results of N=540 children aged between 4;0 and 5;11 years were analyzed. Language impairments were classified into phonetics/phonology (n=44), vocabulary (n=44), grammar (n=58), pragmatics (n=26) and multiple language impairments (n=171). In addition, a distinction was made between deficits in language production and comprehension. The children were compared with an unimpaired control group (n=197). The extent of emotional and behavioural problems were analyzed. The results indicate that emotional and behavioural problems differ depending on the type of language deficit already in preschoolers. Especially deficits in language comprehension, pragmatic impairments and multiple language impairments increase the risk of behavioural and emotional problems and hyperactivity. The relationship between language skills and emotional and behavioural problems should be emphasized in the developmental observation and documentation in preschool. In particular, the distinction between deficits in pragmatics and behavioural problems requires a differentiated examination to ensure an optimal intervention. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Interpersonal Teacher Behaviour and Student Outcomes

    ERIC Educational Resources Information Center

    den Brok, Perry; Brekelmans, Mieke; Wubbels, Theo

    2004-01-01

    In this study, the effectiveness of secondary education teachers' interpersonal behaviour is investigated by analysing data from 2 samples: a study on 45 Physics teachers and their 3rd-year classes and a study on 32 English as a Foreign Language (EFL) teachers and their 3rd-year classes. Teacher interpersonal behaviour was studied by means of…

  4. Health-Promoting Behaviours in Conservatoire Students

    ERIC Educational Resources Information Center

    Kreutz, Gunter; Ginsborg, Jane; Williamon, Aaron

    2009-01-01

    This study focuses on health-promoting behaviours in students from two conservatoires, the Royal Northern College of Music (RNCM, Manchester, UK; n =199) and the Royal College of Music (RCM, London, UK; n = 74). The research questions concern (a) the levels and types of health-promoting behaviours among performance students and (b) the association…

  5. Integrated Programs and Pro-Environmental Behaviour

    ERIC Educational Resources Information Center

    Smith, Tiffany

    2008-01-01

    Research suggested that "nature experience as an education method played a role in developing environmental value and attitudes, and was influential in pro-environmental behaviour." Few of these studies however, assessed the long-term influences of outdoor education experiences on participants' pro-environmental behaviour. The Outward…

  6. Binge eating behaviours in bipolar disorders.

    PubMed

    Boulanger, Hortense; Tebeka, Sarah; Girod, Chloé; Lloret-Linares, Célia; Meheust, Julie; Scott, Jan; Guillaume, Sébastien; Courtet, Philippe; Bellivier, Frank; Delavest, Marine

    2017-08-30

    Recent research, especially from the USA, suggests that comorbid binge eating (BE) behaviour and BE disorder are frequent in individuals with Bipolar Disorder (BD). Although basic clinical associations between BD and BE have been investigated, less is known about psychological or temperamental dimensions and qualitative aspects of eating habits. In a French cohort of patients with BD, we investigated the prevalence of BE behaviour and any associations with illness characteristics, anxiety, impulsivity, emotional regulation and eating habits. 145 outpatients with BD (I and II) were assessed for the presence of BE behaviour using the Binge Eating Scale (BES). Characteristics identified in univariate analyses as differentiating BD cases with and without BE behaviour were then included in a backward stepwise logistic regression (BSLR) model. In this sample, 18.6% of BD patients met criteria for BE behaviour. Multivariate analysis (BSLR) indicated that shorter duration of BD, and higher levels of anxiety and emotional reactivity were observed in BD with compared to BD without BE behaviour. Relatively small sample referred to specialist BD clinics and cross-sectional evaluation meant that it was not possible to differentiate between state and trait levels of impulsivity, emotional instability and disinhibition. These dimensions may also overlap with mood symptoms. BE behaviour is common in females and males with BD. Emotional dysregulation and anxiety may represent important shared vulnerability factors for worse outcome of BD and increased likelihood of BE behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Managing Disruptive Behaviour in the Classroom

    ERIC Educational Resources Information Center

    Deering, Catherine

    2011-01-01

    Both faculty and students at many colleges and universities report numerous incidents of disruptive and uncivil behaviour. However, studies show that faculty are often reluctant to confront these situations, or they feel ill-equipped to intervene. If the behaviour escalates, a disproportionate amount of time and effort can be spent trying to…

  8. Human behaviour: sex ratio and the city.

    PubMed

    Székely, Áron; Székely, Tamás

    2012-09-11

    The ratio of males to females in a population is known to influence the behaviour, life histories and demography of animals. A recent experimental study finds that sex ratio also affects human economic behaviour, and in a manner consistent with evolutionary theory.

  9. Generic flux coupling analysis.

    PubMed

    Reimers, Arne C; Goldstein, Yaron; Bockmayr, Alexander

    2015-04-01

    Flux coupling analysis (FCA) has become a useful tool for aiding metabolic reconstructions and guiding genetic manipulations. Originally, it was introduced for constraint-based models of metabolic networks that are based on the steady-state assumption. Recently, we have shown that the steady-state assumption can be replaced by a weaker lattice-theoretic property related to the supports of metabolic fluxes. In this paper, we further extend our approach and develop an efficient algorithm for generic flux coupling analysis that works with any kind of qualitative pathway model. We illustrate our method by thermodynamic flux coupling analysis (tFCA), which allows studying steady-state metabolic models with loop-law thermodynamic constraints. These models do not satisfy the lattice-theoretic properties required in our previous work. For a selection of genome-scale metabolic network reconstructions, we discuss both theoretically and practically, how thermodynamic constraints strengthen the coupling results that can be obtained with classical FCA. A prototype implementation of tFCA is available at http://hoverboard.io/L4FC. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Too Many Couples

    ERIC Educational Resources Information Center

    Kay, Joseph

    2007-01-01

    In this article, the author offers his ad hoc reflections on the question of just how many academic couples a department could comfortably accommodate from the point of view of good governance, in the hope of getting an honest dialogue started and seeing some reasonable guidelines eventually created by one organization or another as a result. He…

  11. IBEX magnetic coupling experiments

    SciTech Connect

    Frost, C.A.; Kiekel, P.D.; Miller, R.B.; Ekdahl, C.A.; Wagner, J.; Ramirez, J.J.

    1985-01-01

    The magnetic coupling of one pulse to another is a key issue for some modes of high-current beam propagation. Experiments are in progress on Sandia's IBEX accelerator to address issues relevant to magnetic coupling. The IBEX experiments differ from previous experiments in that the B/sub theta/ field acting on the second pulse is the result of residual plasma current from the first pulse rather than current applied by an external means. This new feature makes the propagation sensitive to beam and plasma current profiles that are key to the physics of the magnetic coupling problem. These experiments do not attempt to study the air chemistry issues, as this would require much higher current densities than are available from IBEX. We are using the IBEX accelerator with a mismatched magnetized diode to produce two high-current pulses separated by approx.130 nsec. A pulse pair has been propagated over a 1.5-m path in low pressure air. Extraction of two pulses, each having different parameters, complicates the experiment but also provides new insight into the magnetic coupling proplem. 7 figs.

  12. Coupled Oscillators with Chemotaxis

    NASA Astrophysics Data System (ADS)

    Sawai, Satoshi; Aizawa, Yoji

    1998-08-01

    A simple coupled oscillator system with chemotaxis is introducedto study morphogenesis of cellular slime molds. The modelsuccessfuly explains the migration of pseudoplasmodium which hasbeen experimentally predicted to be lead by cells with higherintrinsic frequencies. Results obtained predict that its velocityattains its maximum value in the interface region between totallocking and partial locking and also suggest possible rolesplayed by partial synchrony during multicellular development.

  13. Coupling Gammasphere and ORRUBA

    SciTech Connect

    Ratkiewicz, A.; Cizewski, J. A.; Manning, B.; Pain, S. D.; Bardayan, D. W.; Blackmon, J. C.; Matos, M.; Chipps, K. A.; Hardy, S.; Shand, C.; Jones, K. L.; Kozub, R. L.; Lister, C. J.; Peters, W. A.; Seweryniak, D.

    2013-04-19

    The coincident detection of particles and gamma rays allows the study of the structure of exotic nuclei via inverse kinematics reactions using radioactive ion beams and thick targets. We report on the status of the project to couple the highresolution charged-particle detector ORRUBA to Gammasphere, a high-efficiency, high-resolution gamma ray detector.

  14. Gravitationally coupled electroweak monopole

    NASA Astrophysics Data System (ADS)

    Cho, Y. M.; Kimm, Kyoungtae; Yoon, J. H.

    2016-10-01

    We present a family of gravitationally coupled electroweak monopole solutions in Einstein-Weinberg-Salam theory. Our result confirms the existence of globally regular gravitating electroweak monopole which changes to the magnetically charged black hole as the Higgs vacuum value approaches to the Planck scale. Moreover, our solutions could provide a more accurate description of the monopole stars and magnetically charged black holes.

  15. The Power of Behavioural Approaches--We Need a Revival

    ERIC Educational Resources Information Center

    Buckley, Sue

    2008-01-01

    Behavioural approaches can be used effectively to teach new skills and to change behaviours that are challenging and not socially adaptive. The behaviour modification approach--now called applied behaviour analysis--is based on the assumption that all behaviours are learned, both the useful ones (new skills) and the ones that are not so useful…

  16. Inhibited attachment behaviour and disinhibited social engagement behaviour as relevant concepts in referred home reared children.

    PubMed

    Scheper, F Y; Abrahamse, M E; Jonkman, C S; Schuengel, C; Lindauer, R J L; de Vries, A L C; Doreleijers, T A H; Jansen, L M C

    2016-07-01

    Disorders of attachment and social engagement have mainly been studied in children, reared in institutions and foster care. There are few studies amongst home reared children living with biological parents. The aim of this study was to test the clinical significance of inhibited attachment behaviour and disinhibited social engagement behaviour in young home reared children, referred for treatment of emotional and behavioural problems, compared with young children in treatment foster care. The Disturbances of Attachment Interview, Maltreatment Classification System, the Child Behaviour Checklist and Parenting Stress Index were used in 141 referred home reared children and 59 referred foster children, aged 2.0-7.9 years (M = 4.7, SE = 1.3), 71% boys. Inhibited attachment behaviour was less prevalent in the referred home reared group (9%) than in the foster care group (27%). Disinhibited social engagement behaviour was found in 42% of the home reared group, similar to the foster care group. Inhibited attachment behaviour and disinhibited social engagement behaviour were not associated with child maltreatment. More inhibited attachment behaviour was associated with clinical levels of child internalizing and externalizing behaviour in the home reared group, not in the foster care group. In both groups, more disinhibited social engagement behaviour was associated with clinical levels of externalizing behaviour and with more parenting stress. Even without evident links to maltreatment, results of this study suggest clinical significance of inhibited attachment behaviour and disinhibited social engagement behaviour in young home reared children referred for treatment of emotional and behavioural problems. © 2016 John Wiley & Sons Ltd.

  17. Relationship factors in skin self-examination among couples.

    PubMed

    Manne, Sharon L; Coups, Elliot J; Kashy, Deborah A

    2016-09-01

    Individuals may be more motivated to adopt health-promoting practices if they consider the benefits of these behaviours for their close relationships. The goal of this study was to use the interdependence theory to evaluate the role of relationship factors in skin self-examination (SSE). The study adopted a cross-sectional survey design. One hundred and eighty-four married couples aged 50 years and older completed measures of skin cancer worry, SSE benefits, SSE barriers, relationship-centred motivations for SSE, discussions about SSE, and SSE practices in the past year. Couples who discussed SSE with one another were more likely to engage in it. Couples who adopted a relationship-centred motivation for SSE were more likely to discuss SSE, and, ultimately, engage in SSE. One partner's beliefs were associated with the other partner's SSE. Women who adopted a relationship-centred motivation for SSE had husbands who discussed SSE more and also had husbands who were more likely to conduct SSE. Men who adopted a relationship-centred motivation for SSE did not have wives who reported that they discussed SSE more with their husbands and/or wives who were more likely to conduct SSE. These findings suggest that wives' relationship beliefs and discussions with their husbands may have a stronger association with their husbands' SSE practices than the associations between husbands' relationship beliefs and discussions with their wives' SSE practices. Behavioural interventions may benefit from encouraging couples to discuss SSE and consider the benefits of SSE for their relationship and for their spouse's health. Statement of contribution What is already known on this subject? Previous studies have shown that people are more motivated to adopt health-promoting behaviours if they consider the benefits of such behaviours for their close relationships. However, little is known about the role of the marital relationship in the engagement in skin self-examination (SSE) practices

  18. Coupled resonator vertical cavity laser

    SciTech Connect

    Choquette, K.D.; Chow, W.W.; Hou, H.Q.; Geib, K.M.; Hammons, B.E.

    1998-01-01

    The monolithic integration of coupled resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the interaction between the cavities. The authors report the first electrically injected coupled resonator vertical-cavity laser diode and demonstrate novel characteristics arising from the cavity coupling, including methods for external modulation of the laser. A coupled mode theory is used model the output modulation of the coupled resonator vertical cavity laser.

  19. Scaling behaviour and superconducting instability in anisotropic non-Fermi liquids

    NASA Astrophysics Data System (ADS)

    Mandal, Ipsita

    2017-01-01

    We study the scaling behaviour of the optical conductivity (σ) , free energy density (F) and shear viscosity of the quantum critical point associated with spin density wave phase transition for a two-dimensional metallic system with C2 symmetry. A non-Fermi liquid behaviour emerges at two pairs of isolated points on the Fermi surface due to the coupling of a bosonic order parameter to fermionic excitations at those so-called "hot-spots". We find that near the hot-spots, σ and F obey the scalings expected for such an anisotropic system, and the direction-dependent viscosity to entropy density ratio is not a universal number due to the anisotropy. Lastly, we also estimate the effect of the fermion-boson coupling at the hot-spots on superconducting instabilities.

  20. GABAA receptor subtype involvement in addictive behaviour.

    PubMed

    Stephens, D N; King, S L; Lambert, J J; Belelli, D; Duka, T

    2017-01-01

    GABAA receptors form the major class of inhibitory neurotransmitter receptors in the mammalian brain. This review sets out to summarize the evidence that variations in genes encoding GABAA receptor isoforms are associated with aspects of addictive behaviour in humans, while animal models of addictive behaviour also implicate certain subtypes of GABAA receptor. In addition to outlining the evidence for the involvement of specific subtypes in addiction, we summarize the particular contributions of these isoforms in control over the functioning of brain circuits, especially the mesolimbic system, and make a first attempt to bring together evidence from several fields to understanding potential involvement of GABAA receptor subtypes in addictive behaviour. While the weight of the published literature is on alcohol dependency, the underlying principles outlined are relevant across a number of different aspects of addictive behaviour. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  1. [Orthorectic eating behaviour - nosology and prevalence rates].

    PubMed

    Barthels, Friederike; Pietrowsky, Reinhard

    2012-12-01

    Orthorectic eating behaviour is characterised by a fixation on a healthy diet and rigidity regarding self-imposed nutrition standards. Besides malnutrition, subjective distress and social isolation might be consequences of clinical relevance. So far there are few reliable data about nosology and prevalence rates, so that it is not yet possible to evaluate the clinical significance of orthorectic eating behaviour. This article discusses nosological classifications of orthorexia and presents prevalence rates of extremely healthy eating behaviour in general population as well as in several specific subgroups. To summarise, orthorectic eating behaviour seems to be most likely an eating disorder with healthy dieting as an overvalued idea. Data on prevelance of orthorectic eating behaviour, assessed with the recently developed Düsseldorfer Orthorexie Skala, suggest a rate of 1 to 2% in general population. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Type A behaviour pattern: a concept revisited.

    PubMed Central

    Rose, M I

    1987-01-01

    It is generally accepted that the type A behaviour pattern is a risk factor in the development of coronary artery disease (CAD). Type A people have been characterized as hard-driving, competitive, aggressive and hurried. A number of investigators have attempted to correlate these facets of type A behaviour with increased risks of CAD. However, there have been conflicting results, primarily owing to differences in methods and CAD outcomes and inconsistencies associated with measuring the type A behaviour pattern. As a result, researchers have begun to focus on subcomponents of the type A behaviour pattern, particularly hostility and anger, that appear to be more reliable predictors of CAD outcome. A reconceptualization of the type A behaviour pattern is required. PMID:3815195

  3. Electron-phonon coupling in quasi-free-standing graphene

    NASA Astrophysics Data System (ADS)

    Johannsen, Jens Christian; Ulstrup, Søren; Bianchi, Marco; Hatch, Richard; Guan, Dandan; Mazzola, Federico; Hornekær, Liv; Fromm, Felix; Raidel, Christian; Seyller, Thomas; Hofmann, Philip

    2013-03-01

    Quasi-free-standing monolayer graphene can be produced by intercalating species like oxygen or hydrogen between epitaxial graphene and the substrate crystal. If the graphene was indeed decoupled from the substrate, one would expect the observation of a similar electronic dispersion and many-body effects, irrespective of the substrate and the material used to achieve the decoupling. Here we investigate the electron-phonon coupling in two different types of quasi-free-standing monolayer graphene: decoupled from SiC via hydrogen intercalation and decoupled from Ir via oxygen intercalation. The two systems show similar overall behaviours of the self-energy and a weak renormalization of the bands near the Fermi energy. The electron-phonon coupling is found to be so weak that it renders the precise determination of the coupling constant λ through renormalization difficult. The estimated value of λ is 0.05(3) for both systems.

  4. Host behaviour-parasite feedback: an essential link between animal behaviour and disease ecology.

    PubMed

    Ezenwa, Vanessa O; Archie, Elizabeth A; Craft, Meggan E; Hawley, Dana M; Martin, Lynn B; Moore, Janice; White, Lauren

    2016-04-13

    Animal behaviour and the ecology and evolution of parasites are inextricably linked. For this reason, animal behaviourists and disease ecologists have been interested in the intersection of their respective fields for decades. Despite this interest, most research at the behaviour-disease interface focuses either on how host behaviour affects parasites or how parasites affect behaviour, with little overlap between the two. Yet, the majority of interactions between hosts and parasites are probably reciprocal, such that host behaviour feeds back on parasites and vice versa. Explicitly considering these feedbacks is essential for understanding the complex connections between animal behaviour and parasite ecology and evolution. To illustrate this point, we discuss how host behaviour-parasite feedbacks might operate and explore the consequences of feedback for studies of animal behaviour and parasites. For example, ignoring the feedback of host social structure on parasite dynamics can limit the accuracy of predictions about parasite spread. Likewise, considering feedback in studies of parasites and animal personalities may provide unique insight about the maintenance of variation in personality types. Finally, applying the feedback concept to links between host behaviour and beneficial, rather than pathogenic, microbes may shed new light on transitions between mutualism and parasitism. More generally, accounting for host behaviour-parasite feedbacks can help identify critical gaps in our understanding of how key host behaviours and parasite traits evolve and are maintained.

  5. Coupled grain boundary motion in aluminium: the effect of structural multiplicity

    PubMed Central

    Cheng, Kuiyu; Zhang, Liang; Lu, Cheng; Tieu, Kiet

    2016-01-01

    The shear-induced coupled grain boundary motion plays an important role in the deformation of nanocrystalline (NC) materials. It has been known that the atomic structure of the grain boundary (GB) is not necessarily unique for a given set of misorientation and inclination of the boundary plane. However, the effect of the structural multiplicity of the GB on its coupled motion has not been reported. In the present study we investigated the structural multiplicity of the symmetric tilt Σ5(310) boundary in aluminium and its influence on the GB behaviour at a temperature range of 300 K–600 K using molecular dynamic simulations. Two starting atomic configurations were adopted in the simulations which resulted in three different GB structures at different temperatures. Under the applied shear deformation each GB structure exhibited its unique GB behaviour. A dual GB behaviour, namely the transformation of one GB behaviour to another during deformation, was observed for the second starting configuration at a temperature of 500 K. The atomistic mechanisms responsible for these behaviour were analysed in detail. The result of this study implicates a strong relationship between GB structures and their behaviour, and provides a further information of the grain boundary mediated plasticity in nanocrystalline materials. PMID:27140343

  6. Growth-coupled overproduction is feasible for almost all metabolites in five major production organisms

    NASA Astrophysics Data System (ADS)

    von Kamp, Axel; Klamt, Steffen

    2017-06-01

    Computational modelling of metabolic networks has become an established procedure in the metabolic engineering of production strains. One key principle that is frequently used to guide the rational design of microbial cell factories is the stoichiometric coupling of growth and product synthesis, which makes production of the desired compound obligatory for growth. Here we show that the coupling of growth and production is feasible under appropriate conditions for almost all metabolites in genome-scale metabolic models of five major production organisms. These organisms comprise eukaryotes and prokaryotes as well as heterotrophic and photoautotrophic organisms, which shows that growth coupling as a strain design principle has a wide applicability. The feasibility of coupling is proven by calculating appropriate reaction knockouts, which enforce the coupling behaviour. The study presented here is the most comprehensive computational investigation of growth-coupled production so far and its results are of fundamental importance for rational metabolic engineering.

  7. Distribution behaviour of acaricide cyflumetofen in tomato during home canning.

    PubMed

    Liu, Na; Dong, Fengshou; Chen, Zenglong; Xu, Jun; Liu, Xingang; Duan, Lifang; Li, Minmin; Zheng, Yongquan

    2016-05-01

    The distribution behaviour of cyflumetofen in tomatoes during home canning was studied. The targeted compound cyflumetofen was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each process step, which included washing, peeling, homogenisation, simmering and sterilisation. Results indicated that more cyflumetofen was removed by washing with detergent solution compared with tap water, 2% NaCl solution and 2% CH3COOH solution. Peeling resulted in 90.2% loss of cyflumetofen and was the most effective step at removing pesticide residues from tomatoes. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PF of the peeling process for cyflumetofen was 0.28.

  8. Couple Reports of the Perceived Influences of a College Human Sexuality Course: An Exploratory Study

    ERIC Educational Resources Information Center

    Henry, Dayna S.

    2013-01-01

    Research on the effects of college sexuality education has been largely quantitative in nature and has focused on changes in individual attitudes, behaviours and knowledge. This study sought to explore, qualitatively, the influences of enrolment in a human sexuality course on relationships. Eight couples from an undergraduate human sexuality…

  9. Couple Reports of the Perceived Influences of a College Human Sexuality Course: An Exploratory Study

    ERIC Educational Resources Information Center

    Henry, Dayna S.

    2013-01-01

    Research on the effects of college sexuality education has been largely quantitative in nature and has focused on changes in individual attitudes, behaviours and knowledge. This study sought to explore, qualitatively, the influences of enrolment in a human sexuality course on relationships. Eight couples from an undergraduate human sexuality…

  10. Matrix Solution of Coupled Differential Equations and Looped Car Following Models

    ERIC Educational Resources Information Center

    McCartney, Mark

    2008-01-01

    A simple mathematical model for the behaviour of how vehicles follow each other along a looped stretch of road is described. The resulting coupled first order differential equations are solved using appropriate matrix techniques and the physical significance of the model is discussed. A number possible classroom exercises are suggested to help…

  11. Matrix Solution of Coupled Differential Equations and Looped Car Following Models

    ERIC Educational Resources Information Center

    McCartney, Mark

    2008-01-01

    A simple mathematical model for the behaviour of how vehicles follow each other along a looped stretch of road is described. The resulting coupled first order differential equations are solved using appropriate matrix techniques and the physical significance of the model is discussed. A number possible classroom exercises are suggested to help…

  12. Thermomechanical analysis of Natural Rubber behaviour stressed at room temperature.

    NASA Astrophysics Data System (ADS)

    Caborgan, R.; Muracciole, J. M.; Wattrisse, B.; Chrysochoos, A.

    2010-06-01

    Owing to their high molecular mobility, stressed rubber chains can easily change their conformations and get orientated. This phenomena leads to so high reversible draw ratio that this behaviour is called rubber elasticity [1-3]. The analogy with ideal gases leads to an internal energy independent of elongation, the stress being attributed to a so-called configuration entropy. However, this analysis cannot take thermal expansion into account and moreover prohibits predicting standard thermo-elastic effect noticed at small elongations and the thermoelastic inversion effects [4]. This paper aims at : observing and quantifying dissipative and coupling effects associated with deformation energy, generated when Natural Rubber is stretched. re-examine the thermomechanical behaviour model of rubberlike materials, under the generalised standard material concept. From an experimental viewpoint, energy balance is created using infrared and quantitative imaging techniques. Digital Image Correlation (DIC) provides in-the-plane displacement fields and, after derivation, strain and strain-rate fields. We have used those techniques to evidence the thermoelastic inversion effect as shown on Figure 1 where different weights have been fixed to warmed specimen and we monitored the sample deformation while it recovers room temperature. But we have also used those techniques to perform energy balance : analysis of the mechanical equilibrium allows estimates of the stress pattern and computation of deformation energy rates under a plane stress hypothesis [5]. Infrared Thermography (IRT) gives the surface temperature of the sample. To estimate the distribution of heat sources, image processing with a local heat equation and a minimal set of approximation functions (image filtering) was used. The time courses of deformation energy and heat associated with cyclic process are plotted in

  13. Magnetic coupling device

    DOEpatents

    Nance, Thomas A [Aiken, SC

    2009-08-18

    A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.

  14. COAXIAL TUBE COUPLING

    DOEpatents

    Niemoth, H.R.

    1963-02-26

    BS>This patent shows a device for quickly coupling coaxial tubes in metal-to-metal fashion, so as to be suitable for use in a nuclear reactor. A threaded coliar urges a tapered metal extension on the outer coaxial tube into a tapered seat in the device and simultaneously exerts pressure through a coaxial helical spring so that a similar extension on the inner tube seats in a similar seat near the other end. (AEC)

  15. Thermal coupling measurement method

    NASA Technical Reports Server (NTRS)

    Rosenthal, L. A.; Menichelli, V. J.

    1974-01-01

    Heat flow from an embedded heated wire responds to a change in the ambient environment. The wire is part of a self-balancing bridge system, and heat flow is measured directly in watts. Steady-state and transient thermal coupling can be measured directly and is an indication of the thermal resistance and diffusivity for the system under study. The method is applied to an aerospace electroexplosive component.

  16. Thermal coupling measurement method

    NASA Technical Reports Server (NTRS)

    Rosenthal, L. A.; Menichelli, V. J.

    1974-01-01

    Heat flow from an embedded heated wire responds to a change in the ambient environment. The wire is part of a self-balancing bridge system, and heat flow is measured directly in watts. Steady-state and transient thermal coupling can be measured directly and is an indication of the thermal resistance and diffusivity for the system under study. The method is applied to an aerospace electroexplosive component.

  17. Quick connect coupling

    NASA Technical Reports Server (NTRS)

    Lomax, Curtis (Inventor); Webbon, Bruce (Inventor)

    1995-01-01

    A cooling apparatus includes a container filled with a quantity of coolant fluid initially cooled to a solid phase, a cooling loop disposed between a heat load and the container, a pump for circulating a quantity of the same type of coolant fluid in a liquid phase through the cooling loop, and a pair of couplings for communicating the liquid phase coolant fluid into the container in a direct interface with the solid phase coolant fluid.

  18. Using robots to understand social behaviour.

    PubMed

    Mitri, Sara; Wischmann, Steffen; Floreano, Dario; Keller, Laurent

    2013-02-01

    A major challenge in studying social behaviour stems from the need to disentangle the behaviour of each individual from the resulting collective. One way to overcome this problem is to construct a model of the behaviour of an individual, and observe whether combining many such individuals leads to the predicted outcome. This can be achieved by using robots. In this review we discuss the strengths and weaknesses of such an approach for studies of social behaviour. We find that robots-whether studied in groups of simulated or physical robots, or used to infiltrate and manipulate groups of living organisms-have important advantages over conventional individual-based models and have contributed greatly to the study of social behaviour. In particular, robots have increased our understanding of self-organization and the evolution of cooperative behaviour and communication. However, the resulting findings have not had the desired impact on the biological community. We suggest reasons for why this may be the case, and how the benefits of using robots can be maximized in future research on social behaviour. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

  19. Risk behaviour and noise exposure among adolescents.

    PubMed

    Bohlin, Margareta C; Erlandsson, Soly I

    2007-01-01

    Adolescents in Western society often expose themselves to high levels of sound in gyms, rock concerts, discotheques etc. As these behaviours are as threatening to young people's health as more traditional risk behaviours are, our aim in the present study was to analyze the relationship between self-exposure to noise, risk behaviours and risk judgements among 310 Swedish adolescents aged 15-20 (167 men; 143 women). Adolescents' behaviour in different traditional risk situations correlated with behaviour in noisy environments, while judgements about traditional risks correlated with judgements regarding noise exposure. It is an interesting finding that although young women judge risk situations as generally more dangerous than young men do, they nevertheless behave in the same way. We suggest that this difference is a social and cultural phenomenon which underscores the importance of adopting a gender perspective in the analysis of risk factors. Adolescents reporting permanent tinnitus judged loud music as more risky than adolescents with no symptoms and they did not listen to loud music as often as those with occasional tinnitus. Research on hearing prevention for young people needs to acknowledge and make use of theories on risk behaviour, especially due to the existence of a relationship between adolescents' risk-taking in noisy environments and other types of risk-taking. Similarly, theories on risk behaviour should acknowledge noise as a risk factor.

  20. Viscoelastic behaviour of cold recycled asphalt mixes

    NASA Astrophysics Data System (ADS)

    Cizkova, Zuzana; Suda, Jan

    2017-09-01

    Behaviour of cold recycled mixes depends strongly on both the bituminous binder content (bituminous emulsion or foamed bitumen) and the hydraulic binder content (usually cement). In the case of cold recycled mixes rich in bitumen and with low hydraulic binder content, behaviour is close to the viscoelastic behaviour of traditional hot mix asphalt. With decreasing bituminous binder content together with increasing hydraulic binder content, mixes are characteristic with brittle behaviour, typical for concrete pavements or hydraulically bound layers. The behaviour of cold recycled mixes with low content of both types of binders is similar to behaviour of unbound materials. This paper is dedicated to analysing of the viscoelastic behaviour of the cold recycled mixes. Therefore, the tested mixes contained higher amount of the bituminous binder (both foamed bitumen and bituminous emulsion). The best way to characterize any viscoelastic material in a wide range of temperatures and frequencies is through the master curves. This paper includes interesting findings concerning the dependency of both parts of the complex modulus (elastic and viscous) on the testing frequency (which simulates the speed of heavy traffic passing) and on the testing temperature (which simulates the changing climate conditions a real pavement is subjected to).

  1. Stress and eating behaviour: implications for obesity.

    PubMed

    Scott, Clare; Johnstone, Alexandra M

    2012-01-01

    This report outlines our strategy to examine the influence of workplace stress on eating behaviour, discussing the current literature which explores the relationship between stress and eating behaviour. This research aims to add to and develop the current understanding of the links between stress and eating behaviour. Specifically the aims are to examine the effect of workplace stress in both day workers and shift workers and their subsequent eating behaviour. The effect of healthy working environment initiatives on stress and eating behaviour will also be examined by comparing a workplace with such an initiative to one with no such initiative. The role of personality on both eating behaviour and stress susceptibility will be examined. In order to achieve this, 450 individuals from 3 public sector workplaces will be recruited. Anthropometric measurements (waist-hip ratio, BMI, visceral fat percentage) will be assessed, as well as personality, eating behaviour profiles, food intake (7-day weighed intake food diary) and both individual daily stressors as well as workplace stress assessed using the demand/control model of job strain will be assessed. Implications for policy and future research are also discussed. Copyright © 2012 S. Karger AG, Basel.

  2. Foraging currencies, metabolism and behavioural routines.

    PubMed

    Houston, Alasdair I; McNamara, John M

    2014-01-01

    A fundamental issue in foraging theory is whether it is possible to find a simple currency that characterizes foraging behaviour. If such a currency exists, then it is tempting to argue that the selective forces that have shaped the evolution of foraging behaviour have been understood. We review previous work on currencies for the foraging behaviour of an animal that maximizes total energy gained. In many circumstances, it is optimal to maximize a suitably modified form of efficiency. We show how energy gain, predation and damage can be combined in a single currency based on reproductive value. We draw attention to the idea that hard work may have an adverse effect on an animal's condition. We develop a model of optimal foraging over a day when a forager's state consists of its energy reserves and its condition. Optimal foraging behaviour in our model depends on energy reserves, condition and time of day. The pattern of optimal behaviour depends strongly on assumptions about the probability that the forager is killed by a predator. If condition is important, no simple currency characterizes foraging behaviour, but behaviour can be understood in terms of the maximization of reproductive value. It may be optimal to adopt a foraging option that results in a rate of energy expenditure that is less than the rate associated with maximizing efficiency.

  3. Conservation of gene function in behaviour

    PubMed Central

    Reaume, Christopher J.; Sokolowski, Marla B.

    2011-01-01

    Behaviour genetic research has shown that a given gene or gene pathway can influence categorically similar behaviours in different species. Questions about the conservation of gene function in behaviour are increasingly tractable. This is owing to the surge of DNA and 'omics data, bioinformatic tools, as well as advances in technologies for behavioural phenotyping. Here, we discuss how gene function, as a hierarchical biological phenomenon, can be used to examine behavioural homology across species. The question can be addressed independently using different levels of investigation including the DNA sequence, the gene's position in a genetic pathway, spatial–temporal tissue expression and neural circuitry. Selected examples from the literature are used to illustrate this point. We will also discuss how qualitative and quantitative comparisons of the behavioural phenotype, its function and the importance of environmental and social context should be used in cross-species comparisons. We conclude that (i) there are homologous behaviours, (ii) they are hard to define and (iii) neurogenetics and genomics investigations should help in this endeavour. PMID:21690128

  4. Phase behaviour of transkarbam 12.

    PubMed

    Zbytovská, Jarmila; Raudenkolb, Steve; Wartewig, Siegfried; Hübner, Wigand; Rettig, Willi; Pissis, Polycarpos; Hrabálek, Alexandr; Dolezal, Pavel; Neubert, Reinhard H H

    2004-04-01

    Transkarbam 12 (T12), the carbamic acid salt of omega-aminocaproic acid dodecyl ester, is a recently synthesized substance, whose high permeation enhancing activity through the human skin was found for certain drugs. In this work, the thermotropic phase behaviour of T12 has been studied by means of various techniques, namely, DSC, FTIR and FT-Raman spectroscopy, X-ray powder diffraction, and DRS. The temperature development of the X-ray reflections as well as of the conformationally sensitive Raman bands and the IR bands have been observed. At room temperature, the hydrocarbon chains of T12 exhibit a highly ordered structure, arranged in an orthorhombic perpendicular subcell. On heating, two transitions occur at 54 and at 66 degrees C. The first transition is related to the disruption of the carbamate structure and changes in the polar head group. The other transition represents the melting of hydrocarbon chains and the subsequent release of carbon dioxide. The time required for the rebinding of carbon dioxide and the reformation of the carbamate structure is dependent upon numerous factors and it was not possible to precisely determine the length of this process.

  5. Internal charge behaviour of nanocomposites

    NASA Astrophysics Data System (ADS)

    Nelson, J. Keith; Fothergill, John C.

    2004-05-01

    The incorporation of 23 nm titanium dioxide nanoparticles into an epoxy matrix to form a nanocomposite structure is described. It is shown that the use of nanometric particles results in a substantial change in the behaviour of the composite, which can be traced to the mitigation of internal charge when a comparison is made with conventional TiO2 fillers. A variety of diagnostic techniques (including dielectric spectroscopy, electroluminescence, thermally stimulated current and photoluminescence) have been used to augment pulsed electro-acoustic space charge measurement to provide a basis for understanding the underlying physics of the phenomenon. It would appear that, when the size of the inclusions becomes small enough, they act cooperatively with the host structure and cease to exhibit interfacial properties, leading to Maxwell-Wagner polarization. It is postulated that the particles are surrounded by high charge concentrations in the Gouy-Chapman-Stern layer. Since nanoparticles have very high specific areas, these regions allow limited charge percolation through nano-filled dielectrics. The practical consequences of this have also been explored in terms of the electric strength exhibited. It would appear that there was a window in which real advantages accrue from the nano-formulated material. An optimum loading of about 10% (by weight) is indicated.

  6. Photochemical behaviour of phenylurea herbicides.

    PubMed

    Amine-Khodja, Amina; Boulkamh, Abdelaziz; Boule, Pierre

    2004-02-01

    The photochemical behaviour of phenylurea herbicides in aqueous solution is highly dependent on the nature and position of substituents on the ring. Most of these herbicides are methylated on the urea moiety, the other substituents are usually halogens or methoxy groups. The main reaction involving the aromatic ring of unhalogenated phenylureas excited at wavelengths shorter than 300 nm is an intramolecular rearrangement, similar to photo-Fries rearrangement, whereas with halogenated derivatives, photohydrolysis is the main transformation pathway. In the particular case of para-halogenated phenylureas, the intermediate formation of a carbene is observed. When the urea moiety is substituted with a methoxyl group, demethoxylation is a competitive reaction. N-Demethylation or oxidation of methyl groups is also observed, but with a lower yield. Photooxidation of phenylureas can also be induced by photocatalysis, iron salts or humic substances. In the absence of water, the main route for phototransformation of diuron is the oxidation or elimination of methyl groups. It is entirely possible that a photochemical intermediate could turn out to be more toxic than the initial herbicide.

  7. Driver irritation and aggressive behaviour.

    PubMed

    Björklund, Gunilla M

    2008-05-01

    A sample of 98 drivers responded to a Swedish version of the UK Driving Anger Scale [UK DAS; [Lajunen, T., Parker, D., Stradling, S.G., 1998. Dimensions of driver anger, aggressive and highway code violations and their mediation by safety orientation in UK drivers. Transport. Res. Part F 1, 107-121]. The results indicated that the Swedish version, like the British original, measures three sources of driver irritation: "progress impeded", "reckless driving", and "direct hostility". Structural equation modelling was used to investigate the relationships between the three sources of self-reported driver irritation, aggressive actions, speed, sex, age, and annual mileage. The models suggested a positive relationship between the amount of driver irritation and frequency of aggressive actions for all three sources of irritation. Female drivers tended to become more irritated than male drivers, while the male drivers tended to act aggressively more often. Surprisingly, drivers who reported that they enjoy fast speeds did not become more irritated than slower drivers when obstructed. The important conclusions are that experienced irritation often leads to openly aggressively actions, and that expression of aggressive behaviours may be a cause of other drivers' feeling of irritation.

  8. Leaching behaviour of synthetic aggregates.

    PubMed

    van der Sloot, H A; Hoede, D; Cresswell, D J; Barton, J R

    2001-01-01

    In the framework of EU project "Utilising innovative kiln technology to recycle waste into synthetic aggregate" (BRST-CT98-5234), the leaching behaviour of synthetic aggregates has been studied to assess its environmental compatibility in the various stages of its use. Since the conditions are very different for the different uses, the assessment calls for a variety of different leaching conditions. The pH dependence test is used to cover important differences in pH environment to which the materials are exposed to as well as for an assessment of the buffering capacity of the material. Synthetic aggregate features a low buffer capacity, which makes it sensitive to externally imposed pH conditions. Utilisation and storage exposed to acidic conditions needs to be avoided. The results of the pH dependence test and column leaching test are mutually consistent. The CEN TC 154 method appears to provide systematically low values due to the arbitrary selection of test conditions. Synthetic aggregate studied to date will not adversely affect the concrete in its service life. The main issue for aggregate use is the recycling and the "end of life" condition, when the material becomes construction debris. Not metals, but oxyanions, such as Cr VI and Mo are most relevant under these conditions. A concise test has been applied to assess crucial aspects of leaching for different production mixes.

  9. Nanospring behaviour of ankyrin repeats.

    PubMed

    Lee, Gwangrog; Abdi, Khadar; Jiang, Yong; Michaely, Peter; Bennett, Vann; Marszalek, Piotr E

    2006-03-09

    Ankyrin repeats are an amino-acid motif believed to function in protein recognition; they are present in tandem copies in diverse proteins in nearly all phyla. Ankyrin repeats contain antiparallel alpha-helices that can stack to form a superhelical spiral. Visual inspection of the extrapolated structure of 24 ankyrin-R repeats indicates the possibility of spring-like behaviour of the putative superhelix. Moreover, stacks of 17-29 ankyrin repeats in the cytoplasmic domains of transient receptor potential (TRP) channels have been identified as candidates for a spring that gates mechanoreceptors in hair cells as well as in Drosophila bristles. Here we report that tandem ankyrin repeats exhibit tertiary-structure-based elasticity and behave as a linear and fully reversible spring in single-molecule measurements by atomic force microscopy. We also observe an unexpected ability of unfolded repeats to generate force during refolding, and report the first direct measurement of the refolding force of a protein domain. Thus, we show that one of the most common amino-acid motifs has spring properties that could be important in mechanotransduction and in the design of nanodevices.

  10. Dynamic Behaviour of Ventilated Hydrofoils.

    NASA Astrophysics Data System (ADS)

    Kjeldsen, Morten; Arndt, Roger; Wosnik, Martin

    2006-11-01

    In certain types of pumping applications oscillations are induced by operation with liquids containing a free gas load. In order to understand the physics of this process, a series of tests with a ventilated A 2D NACA 0015 hydrofoil were performed in the water tunnel at the St. Anthony Falls Laboratory of the University of Minnesota. The special bubble removal feature of the water tunnel allowed continuous ventilation without experiencing visible bubbles upstream the hydrofoil. These studies build on previous work on cavitation-induced oscillations. Gas injection studies were made over a range of gas flow rates and test section pressure. The results clearly show that lift oscillations increase in intensity when the gas load is increased. The point of maximum unsteadiness is also associated the rapid decline of the foil performance as measured as average lift. Further increase of the gas injection load gives a steady behaviour with almost no lift. These experiments are compared with traditional cavitation experiments. The similarities between gas injection- and cavitation induced unsteadiness on the hydrofoil are many, but the amplitude of lift oscillations found on the foil with gas injection corresponds to about 50% of that found for cavitating hydrofoils. The fact that the oscillations are periodic leads to the consideration of both passive and active control.

  11. Epigenetics, brain evolution and behaviour.

    PubMed

    Keverne, Eric B; Curley, James P

    2008-06-01

    Molecular modifications to the structure of histone proteins and DNA (chromatin) play a significant role in regulating the transcription of genes without altering their nucleotide sequence. Certain epigenetic modifications to DNA are heritable in the form of genomic imprinting, whereby subsets of genes are silenced according to parent-of-origin. This form of gene regulation is primarily under matrilineal control and has evolved partly to co-ordinate in-utero development with maternal resource availability. Changes to epigenetic mechanisms in post-mitotic neurons may also be activated during development in response to environmental stimuli such as maternal care and social interactions. This results in long-lasting stable, or short-term dynamic, changes to the neuronal phenotype producing long-term behavioural consequences. Use of evolutionary conserved mechanisms have thus been adapted to modify the control of gene expression and embryonic growth of the brain as well as allowing for plastic changes in the post-natal brain in response to external environmental and social cues.

  12. Quick torque coupling

    DOEpatents

    Luft, Peter A [El Cerrito, CA

    2009-05-12

    A coupling for mechanically connecting modular tubular struts of a positioning apparatus or space frame, comprising a pair of toothed rings (10, 12) attached to separate strut members (16), the teeth (18, 20) of the primary rings (10, 12) mechanically interlocking in both an axial and circumferential manner, and a third part comprising a sliding, toothed collar (14) the teeth (22) of which interlock the teeth (18, 20) of the primary rings (10, 12), preventing them from disengaging, and completely locking the assembly together. A secondary mechanism provides a nesting force for the collar, and/or retains it. The coupling is self-contained and requires no external tools for installation, and can be assembled with gloved hands in demanding environments. No gauging or measured torque is required for assembly. The assembly can easily be visually inspected to determine a "go" or "no-go" status. The coupling is compact and relatively light-weight. Because of it's triply interlocking teeth, the connection is rigid. The connection does not primarily rely on clamps, springs or friction based fasteners, and is therefore reliable in fail-safe applications.

  13. Mechanochemical Coupling in Flagella

    PubMed Central

    Brokaw, C. J.; Benedict, B.

    1968-01-01

    The relation between oxygen consumption and motility of Ciona spermatozoa has been measured by using pH stats to measure the acid production of spermatozoa swimming in dilute suspensions where their motility can be analyzed accurately, and calibrating the acid production by measuring it simultaneously with measurements of oxygen consumption, using more concentrated sperm suspensions. When the motility of the spermatozoa is inhibited by thiourea or by increased viscosity, their oxygen consumption decreases in proportion to the decrease in beat frequency. 80–85 % of their oxygen consumption appears to be tightly coupled to motility. The amount of movement-coupled oxidative metabolism per beat remains nearly constant, even when there are significant changes in the energy required per beat for movement against the viscous resistance of the medium. This implies that under these conditions, where the radius of curvature of flagellar bending remains constant, the amount of ATP used is determined by a stoichiometric relation to bending rather than by the energy requirement. The movement-coupled oxidative metabolism appears to be sufficient to generate approximately two molecules of ATP per beat for each molecule of the flagellar ATPase, dynein. PMID:4234210

  14. Dynamic coupling of plasmonic resonators

    PubMed Central

    Lee, Suyeon; Park, Q-Han

    2016-01-01

    We clarify the nature of dynamic coupling in plasmonic resonators and determine the dynamic coupling coefficient using a simple analytic model. We show that plasmonic resonators, such as subwavelength holes in a metal film which can be treated as bound charge oscillators, couple to each other through the retarded interaction of oscillating screened charges. Our dynamic coupling model offers, for the first time, a quantitative analytic description of the fundamental symmetric and anti-symmetric modes of coupled resonators which agrees with experimental results. Our model also reveals that plasmonic electromagnetically induced transparency arises in any coupled resonators of slightly unequal lengths, as confirmed by a rigorous numerical calculation and experiments. PMID:26911786

  15. Sociodemographic and Behavioural Determinants of a Healthy Diet in Switzerland.

    PubMed

    Marques-Vidal, Pedro; Waeber, Gérard; Vollenweider, Peter; Bochud, Murielle; Stringhini, Silvia; Guessous, Idris

    2015-01-01

    The determinants of a healthy diet have not been studied in Switzerland. This study aimed at assessing the individual and behavioural factors associated with a healthy diet in a Swiss city. Cross-sectional, population-based study conducted between 2009 and 2013 (n = 4,439, 2,383 women, mean age 57.5 ± 10.3 years) in Lausanne. Food consumption was assessed using a validated food frequency questionnaire. Two Mediterranean diet scores (classic score and specific for Switzerland) and the Harvard School of Public Health alternate healthy eating index were computed. For all three dietary scores considered, living in couple or having a high education were associated with a healthier diet. An unhealthy lifestyle (smoking, sedentary behaviour) or a high body mass index were associated with an unhealthier diet. Participants born in Italy, Portugal and Spain had healthier diets than participants born in France or Switzerland. Women and elderly participants had healthier diets than men and young participants according to 2 scores, while no differences were found for the Swiss-specific Mediterranean score. In Switzerland, healthy eating is associated with high education, a healthy lifestyle, marital status and country of origin. The associations with gender and age depend on the dietary score considered. © 2015 S. Karger AG, Basel.

  16. Precise Specification of Design Pattern Structure and Behaviour

    NASA Astrophysics Data System (ADS)

    Sterritt, Ashley; Clarke, Siobhán; Cahill, Vinny

    Applying design patterns while developing a software system can improve its non-functional properties, such as extensibility and loose coupling. Precise specification of structure and behaviour communicates the invariants imposed by a pattern on a conforming implementation and enables formal software verification. Many existing design-pattern specification languages (DPSLs) focus on class structure alone, while those that do address behaviour suffer from a lack of expressiveness and/or imprecise semantics. In particular, in a review of existing work, three invariant categories were found to be inexpressible in state-of-the-art DPSLs: dependency, object state and data-structure. This paper presents Alas: a precise specification language that supports design-pattern descriptions including these invariant categories. The language is based on UML Class and Sequence diagrams with modified syntax and semantics. In this paper, the meaning of the presented invariants is formalized and relevant ambiguities in the UML Standard are clarified. We have evaluated Alas by specifying the widely-used Gang of Four pattern catalog and identified patterns that benefitted from the added expressiveness and semantics of Alas.

  17. Male behaviours towards unplanned pregnancy: experiences of Brazilian low-income women.

    PubMed

    Hoga, L A K; Manganiello, A

    2007-12-01

    Lone women are responsible for a quarter of Brazilian families. The unplanned pregnancy, a strong reality for many young poor women in this country, provokes a strong impact on physical, emotional, socio-economic and family dimensions. Do personal characteristics determine the behaviours of males towards unplanned pregnancy? Do the associations between the couple's bond and male behaviours influence attitudes towards unplanned pregnancy? This descriptive study was carried out in a low-income community in the City of São Paulo, Brazil. A structured form was composed to obtain data from 100 women who have lived out the unplanned pregnancy experience. Personal characteristics do not appear to determine male behaviours towards unplanned pregnancy. There was a statistically significant difference among men in different types of bonding relationship (married, cohabiting, dating, without bonding) with regard to the following behaviours: attention given during pregnancy; changes to the type of bond between partners; civil registration of the child by the father; financial support provided by the father and contact with the child. Bonding and correlated topics are essential in sexual and reproductive healthcare education and promotion. Population sampling was statistically calculated based on community demographic data and the conclusions refer to the estimated parameters of men's behaviours according to women's experiences.

  18. High-risk behaviour in hypomanic states.

    PubMed

    Fletcher, Kathryn; Parker, Gordon; Paterson, Amelia; Synnott, Howe

    2013-08-15

    Risk-taking behaviours during hypomanic states are recognised, however the high-risk nature of some behaviours-including the potential for harm to both the individual and others-has not been detailed in the research literature. The current study examines risk-taking behaviours and their consequences (including their potential for impairment) in those with a bipolar II condition. Participants were recruited from the Sydney-based Black Dog Institute Depression Clinic. Diagnostic assignment of bipolar II disorder was based on clinician judgement and formal DSM-IV criteria. Participants completed a series of detailed questions assessing previous risk-taking behaviours during hypomanic states. The sample comprised a total of 93 participants. Risk-taking behaviours during hypomania included spending significant amounts of money, excessive alcohol or drug use, dangerous driving and endangering sexual activities. Key consequences included interpersonal conflict, substantial financial burden and feelings of guilt, shame and remorse. Despite recognition of the risks and consequences associated with hypomanic behaviours, less than one-fifth of participants agreed that hypomania should be treated because of the associated risks. Study limitations included a cross-sectional design, reliance on self-report information, lack of controlling for current mood state, and comprised a tertiary referral sample that may be weighted to more severe cases. Findings may therefore not be generalisable and require replication. Risk-taking behaviours during hypomania are common, and often linked with serious consequences. Whilst hypomania is often enjoyed and romanticised by patients-leading to ambivalence around treatment of such states-careful consideration of the impact of risk-taking behaviour is necessary, while the study raises the question as to what is 'impairment' in hypomania. Findings should advance clinical management by identifying those high-risk behaviours that would benefit from

  19. Behavioural responses of larval container mosquitoes to a size-selective predator.

    PubMed

    Kesavaraju, Banugopan; Alto, Barry W; Lounibos, L Philip; Juliano, Steven A

    2007-06-01

    The hypothesis that size-selective predation and species-specific prey behaviours facilitate the coexistence between larvae of invasive Aedes albopictus (Skuse) and U.S.A.-native Ochlerotatus triseriatus (Say) was tested experimentally with the predator Corethrella appendiculata (Grabham).Larval behaviours associated with a higher risk of predation were identified, and prey behavioural responses were tested in either the physical presence of predators or in water containing predation cues. Larvae that thrashed on container bottoms had a higher risk of being captured by fourth instar C. appendiculata than did larvae resting on the water surface. Ochlerotatus triseriatus, but not A. albopictus, adopted low-risk behaviours in response to water-borne cues to predation. Both prey species reduced risky behaviours in the physical presence of the predator, but O. triseriatus showed a stronger response.The vulnerability of 2nd and 3rd instar prey to predation was compared, and behavioural responses were correlated with prey vulnerability. Second instars of both species were more vulnerable to predation by C. appendiculata than were 3rd instars, and the 3rd instar A. albopictus was more vulnerable than O. triseriatus of the same stage. All instars of O. triseriatus showed a similar reduction of risky behaviours in response to the presence of C. appendiculata despite 4th instar prey being relatively invulnerable to size-selective predation.Weaker predator avoidance, coupled with superior competitive ability, of invasive A. albopictus is likely to contribute to its coexistence with O. triseriatus in containers of the south-eastern U.S.A., where C. appendiculata can be abundant.

  20. Irradiation behaviour of uranium silicide compounds

    NASA Astrophysics Data System (ADS)

    Finlay, M. R.; Hofman, G. L.; Snelgrove, J. L.

    2004-02-01

    A study of the irradiation behaviour of uranium silicide and other related inter-metallic uranium compounds is presented. This study was motivated by the recent discovery that U 3Si 2 undergoes a crystalline to amorphous transformation during irradiation. Such information renders a previously developed fuel swelling model based on the crystalline state of U 3Si 2 invalid. This is of particular significance since low enriched U 3Si 2 dispersion fuels are widely used in research reactors. While such a finding does not alter the well established, stable and benign behaviour of U 3Si 2 during irradiation, it does indicate that a different interpretation of that behaviour is required.