WorldWideScience

Sample records for motive force-driven uptake

  1. Energizing porters by proton-motive force.

    Science.gov (United States)

    Nelson, N

    1994-11-01

    It is generally accepted that the chemistry of water was the most crucial determinant in shaping life on earth. Among the more important chemical features of water is its dissociation into protons and hydroxyl ions. The presence of relatively high proton concentrations in the ambient solution resulted in the evolution of proton pumps during the dawn of life on earth. These proton pumps maintained neutral pH inside the cells and generated electrochemical gradients of protons (proton-motive force) across their membranes. The existence of proton-motive force enabled the evolution of porters driven by it that are most probably among the more primitive porters in the world. The directionality of the substrate transport by the porters could be to both sides of the membranes because they can serve as proton symporters or antiporters. One of the most important subjects of this meeting is the mechanism by which proton-motive and other ion-motive forces drive the transport processes through porters. Is there a common mechanism of action for all proton-driven porters? Is there some common partial reaction by which we can identify the way that porters are energized by proton-motive force? Is there a common coupling between proton movement and uptake or secretion of certain molecules? Even a partial answer to one of these questions would advance our knowledge... or confusion. As my mentor Efraim Racker used to say: 'If you are not totally confused you do not understand the issue'.

  2. Spin motive force driven by the magnetization dynamics in chiral magnets

    International Nuclear Information System (INIS)

    Ohe, Jun-ichiro; Shimada, Yuhki

    2015-01-01

    The magnetization dynamics induces the spin-dependent force on the conduction electrons via the s-d coupling. We have investigated numerically this force, so called 'spin-motive force', generated in chiral magnets forming the Skyrmion structure. We solve the Landau-Lifshitz-Gilbert equation and obtain the Skyrmion lattice structure (SkX) by introducing the Dzyaloshinskii-Moriya (DM) interaction. The corrective mode of the Skyrmion core is obtained by applying the in-plane AC magnetic field. The spin-motive force is generated perpendicular to the velocity of the Skyrmion core. The total voltage due to the spin-motive force is enhanced by the cascade effect of the voltage for each Skyrmion core. For the isolated magnetic disc system, the corrective mode of the Skyrmion lattice is modulated from that of the bulk system by the influence of the edge structure. The phase-locking motion of each Skyrmion core is obtained only in the lowest frequency mode in which the cascade effect of the spin-motive force still remain. (author)

  3. Regulation of dextransucrase secretion by proton motive force in Leuconostoc mesenteroides

    International Nuclear Information System (INIS)

    Otts, D.R.

    1987-01-01

    The relationship between proton motive force and the secretion of the enzyme dextransucrase in Leuconostoc mesenteroides was investigated. The transmembrane pH gradient was determined by measurement of the uptake of radiolabeled benzoate or methylamine while the membrane potential was determined by measurement of the uptake of radiolabeled tetraphenylphosphonium bromide. Leuconostoc mesenteroides was able to maintain a constant proton motive force of -130 mV when grown in fermenters at constant pH while a value of -140 mV was determined from concentrated cell suspensions. The contribution of the membrane potential and transmembrane pH gradient to the proton motive force varied depending on the cation concentration and pH of the medium. The results of this study strongly indicate that dextransucrase secretion Leuconostoc mesenteroides is dependent on the presence of a proton gradient across the cytoplasmic membrane. The results further suggest that dextransucrase secretion is coupled to proton influx into the cell

  4. Spin motive forces due to magnetic vortices and domain walls

    NARCIS (Netherlands)

    Lucassen, M.E.; Kruis, G.C.F.L.; Lavrijsen, R.; Swagten, H.J.M.; Koopmans, B.; Duine, R.A.

    2011-01-01

    We study spin motive forces, that is, spin-dependent forces and voltages induced by time-dependent magnetization textures, for moving magnetic vortices and domain walls. First, we consider the voltage generated by a one-dimensional field-driven domain wall. Next, we perform detailed calculations on

  5. Lactose uptake driven by galactose efflux in Streptococcus thermophilus: Evidence for a galactose-lactose antiporter

    International Nuclear Information System (INIS)

    Hutkins, R.W.; Ponne, C.

    1991-01-01

    Galactose-nonfermenting (Gal - ) Streptococcus thermophilus TS2 releases galactose into the extracellular medium when grown in medium containing excess lactose. Starved and de-energized Gal - cells, however, could be loaded with galactose to levels approximately equal to the extracellular concentration (0 to 50 mM). When loaded cells were separated from the medium and resuspended in fresh broth containing 5 mM lactose, galactose efflux occurred. De-energized, galactose-loaded cells, resuspended in buffer or medium, accumulated [ 14 C]lactose at a greater rate and to significantly higher intracellular concentrations than unloaded cells. Uptake of lactose by loaded cells was inhibited more than that by unloaded cells in the presence of extracellular galactose, indicating that a galactose gradient was involved in the exchange system. When de-energized, galactose-loaded cells were resuspended in carbohydrate-free medium at pH 6.7, a proton motive force (Δp) of 86 to 90 mV was formed, whereas de-energized, nonloaded cells maintained a Δp of about 56 mV. However, uptake of lactose by loaded cells occurred when the proton motive force was abolished by the addition of an uncoupler or in the presence of a proton-translocating ATPase inhibitor. These results support the hypothesis that galactose efflux in Gal - S. thermophilus is electrogenic and that the exchange reaction (lactose uptake and galactose efflux) probably occurs via an antiporter system

  6. Behavioural Motives of Acquisition of Solar-driven Equipment

    Directory of Open Access Journals (Sweden)

    Shkurupska Iryna O.

    2013-12-01

    Full Text Available The article identifies needs of the target group, namely structure of motives, which justify making a decision to buy, in order to create efficient marketing strategy of an enterprise, which sell solar-driven equipment in Ukraine. There are five segments in the domestic market of helio-systems: individual consumers, recreation industry, agrarian industry, construction and social spheres. The article allocates 15 motives of acquisition of the solar-driven equipment for these segments, the most important of which are price, availability of solar energy, alternative price and energy saving. Besides, the structure of such motives is determined for each segment individually. In order to choose specific marketing instruments in the policy of promotion of solar-driven equipment, the article identifies differences in the form of goals of use and motives of acquisition between the specified consumer segments. The article reveals certain barriers that interfere with acquisition of solar-driven equipment – low level of trust into helio-systems, conservatism of consumers, absence of free applications for consumers – overcoming which is only possible with the help of certain marketing actions.

  7. Encouraging contraceptive uptake by motivating men to communicate about family planning: the Malawi Male Motivator project.

    Science.gov (United States)

    Shattuck, Dominick; Kerner, Brad; Gilles, Kate; Hartmann, Miriam; Ng'ombe, Thokozani; Guest, Greg

    2011-06-01

    We examined the effect of a peer-delivered educational intervention, the Malawi Male Motivator intervention, on couples' contraceptive uptake. We based the intervention design on the information-motivation-behavioral skills (IMB) model. In 2008 we recruited 400 men from Malawi's Mangochi province who reported not using any method of contraception. We randomized them into an intervention arm and a control arm, and administered surveys on contraceptive use at baseline and after the intervention. We also conducted in-depth interviews with a subset of intervention participants. After the intervention, contraceptive use increased significantly within both arms (P communication within couples were the only significant predictors of uptake (P communication skills are essential mechanisms for successfully enabling men to help couples use a contraceptive.

  8. Light-driven photosensitizer uptake increases Candida albicans photodynamic inactivation.

    Science.gov (United States)

    Romano, Renan A; Pratavieira, Sebastião; Silva, Ana P da; Kurachi, Cristina; Guimarães, Francisco E G

    2017-11-01

    Photodynamic Inactivation (PDI) is based on the use of a photosensitizer (PS) and light that results mainly in the production of reactive oxygen species, aiming to produce microorganism cell death. PS incubation time and light dose are key protocol parameters that influence PDI response; the correct choice of them can increase the efficiency of inactivation. The results of this study show that a minor change in the PDI protocol, namely light-driven incubation leads to a higher photosensitizer and more uniform cell uptake inside the irradiated zone. Furthermore, as the uptake increases, the damage caused by PDI also increases. The proposed light-driven incubation prior to the inactivation illumination dose has advantages when compared to the traditional PDI treatments since it can be more selective and effective. Using a violet light as pre-illumination (light-driven incubation) source and a red-light system as PDI source, it was possible to demonstrate that when compared to the traditional protocol of dark incubation, the pre-illuminated cell culture showed an inactivation increase of 7 log units. These in vitro results performed in Candida albicans cells may result in the introduction of a new protocol for PDI. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The nature of motive force

    CERN Document Server

    Pramanick, Achintya Kumar

    2014-01-01

    In this monograph Prof. Pramanick explicates the law of motive force, a fundamental law of nature that can be observed and appreciated as an addition to the existing laws of thermodynamics. This unmistakable and remarkable tendency of nature is equally applicable to all other branches of studies. He first conceptualized the law of motive force in 1989, when he was an undergraduate student. Here he reports various applications of the law in the area of  thermodynamics, heat transfer, fluid mechanics and solid mechanics, and shows how it is possible to solve analytically century-old unsolved problems through its application. This book offers a comprehensive account of the law and its relation to other laws and principles, such as the generalized conservation principle, variational formulation, Fermat’s principle, Bejan’s constructal law, entropy generation minimization, Bejan’s method of intersecting asymptotes and equipartition principle. Furthermore, the author addresses some interrelated fundamental p...

  10. Generation of spin motive force in a soliton lattice

    International Nuclear Information System (INIS)

    Ovchinnikov, A. S.; Sinitsyn, V. E.; Bostrem, I. G.; Kishine, J.

    2013-01-01

    The generation of a spin motive force in a chiral helimagnet due to the action of two crossed magnetic fields is considered. The cases of pulsed and periodic magnetic fields directed along the helical axis under a perpendicular dc field are analyzed. It is shown that, in the case of a pulsed field, the spin motive force is related to dissipation, whereas in a periodic field, there is a reactive component that is not related to damping processes.

  11. Intrinsic and extrinsic motivation is associated with computer-based auditory training uptake, engagement, and adherence for people with hearing loss

    Directory of Open Access Journals (Sweden)

    Helen eHenshaw

    2015-08-01

    Full Text Available Hearing aid intervention typically occurs after significant delay, or not at all, resulting in an unmet need for many people with hearing loss. Computer-based auditory training (CBAT may provide generalized benefits to real-world listening, particularly in adverse listening conditions, and can be conveniently delivered in the home environment. Yet as with any intervention, adherence to CBAT is critical to its success. The main aim of this investigation was to explore motivations for uptake, engagement and adherence with home-delivered CBAT in a randomized controlled trial of adults with mild sensorineural hearing loss (SNHL, with a view to informing future CBAT development. A secondary aim examined perceived benefits of CBAT.Participants (n = 44, 50-74 year olds with mild SNHL who did not have hearing aids completed a four-week program of phoneme discrimination CBAT at home. Participants’ experiences of CBAT were captured using a post-training questionnaire (n = 44 and two focus groups (n = 5 per group. A mixed-methods approach examined participants’ experiences with the intervention, the usability and desirability of the CBAT software, and participants’ motivations for CBAT uptake, engagement and adherence. Self-Determination Theory was used as a theoretical framework for the interpretation of results. Participants found the CBAT intervention easy to use, interesting and enjoyable. Initial participation in the study was associated with extrinsic motivation (e.g. hearing difficulties. Engagement and adherence with CBAT was influenced by intrinsic (e.g. a desire to achieve higher scores, and extrinsic (e.g. to help others with hearing loss motivations. Perceived post-training benefits included better concentration and attention leading to improved listening. CBAT also prompted further help-seeking behaviors for some individuals. We see this as an important first-step for informing future theory-driven development of effective CBAT

  12. Intrinsic and extrinsic motivation is associated with computer-based auditory training uptake, engagement, and adherence for people with hearing loss.

    Science.gov (United States)

    Henshaw, Helen; McCormack, Abby; Ferguson, Melanie A

    2015-01-01

    Hearing aid intervention typically occurs after significant delay, or not at all, resulting in an unmet need for many people with hearing loss. Computer-based auditory training (CBAT) may provide generalized benefits to real-world listening, particularly in adverse listening conditions, and can be conveniently delivered in the home environment. Yet as with any intervention, adherence to CBAT is critical to its success. The main aim of this investigation was to explore motivations for uptake, engagement and adherence with home-delivered CBAT in a randomized controlled trial of adults with mild sensorineural hearing loss (SNHL), with a view to informing future CBAT development. A secondary aim examined perceived benefits of CBAT. Participants (n = 44, 50-74 years olds with mild SNHL who did not have hearing aids) completed a 4-week program of phoneme discrimination CBAT at home. Participants' experiences of CBAT were captured using a post-training questionnaire (n = 44) and two focus groups (n = 5 per group). A mixed-methods approach examined participants' experiences with the intervention, the usability and desirability of the CBAT software, and participants' motivations for CBAT uptake, engagement and adherence. Self-Determination Theory (SDT) was used as a theoretical framework for the interpretation of results. Participants found the CBAT intervention easy to use, interesting and enjoyable. Initial participation in the study was associated with extrinsic motivation (e.g., hearing difficulties). Engagement and adherence with CBAT was influenced by intrinsic (e.g., a desire to achieve higher scores), and extrinsic (e.g., to help others with hearing loss) motivations. Perceived post-training benefits included better concentration and attention leading to improved listening. CBAT also prompted further help-seeking behaviors for some individuals. We see this as an important first-step for informing future theory-driven development of effective CBAT interventions.

  13. Ponderomotive force effects on temperature-gradient-driven instabilities

    International Nuclear Information System (INIS)

    Sundaram, A.K.; Hershkowitz, N.

    1992-01-01

    The modification of temperature-gradient-driven instabilities due to the presence of nonuniform radio-frequency fields near the ion cyclotron frequency is investigated in the linear regime. Employing the fluid theory, it is shown that the induced field line compression caused by ion cyclotron range of frequencies (ICRF) fields makes the net parallel compressibility positive, and thus provides a stabilizing influence on the ion-temperature-gradient-driven mode for an appropriately tailored profile of radio-frequency (rf) pressure. Concomitantly, the radial ponderomotive force generates an additional contribution via coupling between the perturbed fluid motion and the equilibrium ponderomotive force and this effect plays the role of dissipation to enhance or decrease the growth of temperature-gradient-driven modes depending upon the sign of rf pressure gradients. For decreased growth of temperature-gradient-driven instabilities, the plasma density gradients and rf pressure gradients must have opposite signs while enhancement in growth arises when both gradients have the same sign. Finally, the kinetic effects associated with these modes are briefly discussed

  14. Ocean Heat Uptake Slows 21st Century Surface Warming Driven by Extratropical Cloud Feedbacks

    Science.gov (United States)

    Frey, W.; Maroon, E.; Pendergrass, A. G.; Kay, J. E.

    2017-12-01

    Equilibrium climate sensitivity (ECS), the warming in response to instantaneously doubled CO2, has long been used to compare climate models. In many models, ECS is well correlated with warming produced by transient forcing experiments. Modifications to cloud phase at high latitudes in a state-of-the-art climate model, the Community Earth System Model (CESM), produce a large increase in ECS (1.5 K) via extratropical cloud feedbacks. However, only a small surface warming increase occurs in a realistic 21st century simulation including a full-depth dynamic ocean and the "business as usual" RCP8.5 emissions scenario. In fact, the increase in surface warming is only barely above the internal variability-generated range in the CESM Large Ensemble. The small change in 21st century warming is attributed to subpolar ocean heat uptake in both hemispheres. In the Southern Ocean, the mean-state circulation takes up heat while in the North Atlantic a slowdown in circulation acts as a feedback to slow surface warming. These results show the importance of subpolar ocean heat uptake in controlling the pace of warming and demonstrate that ECS cannot be used to reliably infer transient warming when it is driven by extratropical feedbacks.

  15. Motivators of couple HIV counseling and testing (CHCT uptake in a rural setting in Uganda

    Directory of Open Access Journals (Sweden)

    Victoria Nannozi

    2017-01-01

    Full Text Available Abstract Background Couple HIV Counseling and Testing (CHCT is one of the key preventive strategies used to reduce the spread of HIV. In Uganda, HIV prevalence among married/living together is 7.2% among women and 7.6% among men. CHCT can help ease disclosure of HIV-positive status, which in turn may help increase opportunities to get social support and reduce new infections. The uptake of CHCT among attendees of health facilities in rural Uganda is as high as 34%. The purpose of this study was to explore the motivators of CHCT uptake in Mukono district, a rural setting in Uganda. Methods The study was conducted in two sub-counties in a rural district (Mukono district about 28 km east of the capital Kampala, using a descriptive and explorative qualitative research design. Specifically, we conducted focus group discussions and key informant interviews with HIV focal persons, village health team (VHT members, religious leaders and political leaders. We also interviewed persons in couple relationships. Data was analysed using NVivo 8 software. Ethical clearance was received from the Mengo Hospital Research Review Board and from the Uganda National Council of Science and Technology. Results The study was conducted from June 2013 to July 2013 We conducted 4 focus group discussions, 10 key informant interviews and interviewed 53 persons in couple relationships. None of the participants were a couple. The women were 68% (36/53 and 49% (26/53 of them were above 29 years old. The motivators of CHCT uptake were; perceived benefit of HIV testing, sickness of a partner or child in the family and suspicion of infidelity. Other important motivators were men involvement in antenatal care (ANC attendance and preparation for marriage. Conclusion The motivators for CHCT uptake included the perceived benefit of HIV testing, sickness of a partner or child, preparation for marriage, lack of trust among couples and men involvement in antenatal care. Greater

  16. Motivators of couple HIV counseling and testing (CHCT) uptake in a rural setting in Uganda.

    Science.gov (United States)

    Nannozi, Victoria; Wobudeya, Eric; Matsiko, Nicholas; Gahagan, Jacqueline

    2017-01-23

    Couple HIV Counseling and Testing (CHCT) is one of the key preventive strategies used to reduce the spread of HIV. In Uganda, HIV prevalence among married/living together is 7.2% among women and 7.6% among men. CHCT can help ease disclosure of HIV-positive status, which in turn may help increase opportunities to get social support and reduce new infections. The uptake of CHCT among attendees of health facilities in rural Uganda is as high as 34%. The purpose of this study was to explore the motivators of CHCT uptake in Mukono district, a rural setting in Uganda. The study was conducted in two sub-counties in a rural district (Mukono district) about 28 km east of the capital Kampala, using a descriptive and explorative qualitative research design. Specifically, we conducted focus group discussions and key informant interviews with HIV focal persons, village health team (VHT) members, religious leaders and political leaders. We also interviewed persons in couple relationships. Data was analysed using NVivo 8 software. Ethical clearance was received from the Mengo Hospital Research Review Board and from the Uganda National Council of Science and Technology. The study was conducted from June 2013 to July 2013 We conducted 4 focus group discussions, 10 key informant interviews and interviewed 53 persons in couple relationships. None of the participants were a couple. The women were 68% (36/53) and 49% (26/53) of them were above 29 years old. The motivators of CHCT uptake were; perceived benefit of HIV testing, sickness of a partner or child in the family and suspicion of infidelity. Other important motivators were men involvement in antenatal care (ANC) attendance and preparation for marriage. The motivators for CHCT uptake included the perceived benefit of HIV testing, sickness of a partner or child, preparation for marriage, lack of trust among couples and men involvement in antenatal care. Greater attention to enhancers of CHCT programming is needed in trying to

  17. In Search for Anchors The Fundamental Motivational Force in Compensating for Human Vulnerability

    Directory of Open Access Journals (Sweden)

    Bagus Riyono

    2012-09-01

    Full Text Available The purpose of this study is to develop a new integrative theory of motivation drawn from the existing theories and data. The method used is a combination of meta-ethnography and grounded theory. The second phase of the study employed a thought experiment to test the newly developed theoretical propositions of motivational force. The first phase of the study revealed a central phenomenon for the occurrence of motivational force, i.e. “In Search for Anchors,” which is a result of the paradox between freedom to choose and human vulnerability. “Freedom to choose” is the central factor of a motivational model that includes “urge,” “challenge,” “incentive,” and “meaning.” These five factors are motivational sources, which have holistic-dynamic-integrative interaction. Human vulnerability is the other side of the motivational model that comprises risk, uncertainty, and hope that ignite motivational force. The dynamic interaction of risk, uncertainty, and hope is represented in a mathematical formula that produces the strength of the force, (R – H2 x U, which can be potrayed in a “twin-peak” curve. The thought experiment was conducted to test the hypothetical formula. The result shows that the “twin-peak” hypothesis is supported but the shape of the curve is found to be not symmetrical. The data show that hope is the strongest motivational force, therefore the formula is modified into = (R – U2 x H. The implication of the study and the utility of the new theory are discussed.

  18. User-driven Points for Feedback Motivated Electricity savings in Private Households

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Christiansen, Ellen Tove

    This paper reports from a study of design and exploration of feedback for motivated electricity consumption to private households based on user-driven innovation. Traditionally feedback is designed on the basis of technical possibilities and/or theories on consumer behavior. In this study we...

  19. Ratchet effect on a relativistic particle driven by external forces

    Energy Technology Data Exchange (ETDEWEB)

    Quintero, Niurka R [Departamento de Fisica Aplicada I, Escuela Universitaria Politecnica, Universidad de Sevilla, Calle Virgen de Africa 7, E-41011 Sevilla (Spain); Alvarez-Nodarse, Renato [Departamento de Analisis Matematico, Facultad de Matematicas, Universidad de Sevilla, Apdo 1160, E-41080 Sevilla (Spain); Cuesta, Jose A, E-mail: niurka@us.es, E-mail: ran@us.es, E-mail: cuesta@math.uc3m.es [Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matematicas, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911 Leganes, Madrid (Spain)

    2011-10-21

    We study the ratchet effect of a damped relativistic particle driven by both asymmetric temporal bi-harmonic and time-periodic piecewise constant forces. This system can be formally solved for any external force, providing the ratchet velocity as a nonlinear functional of the driving force. This allows us to explicitly illustrate the functional Taylor expansion formalism recently proposed for this kind of systems. The Taylor expansion reveals particularly useful to obtain the shape of the current when the force is periodic, piecewise constant. We also illustrate the somewhat counterintuitive effect that introducing damping may induce a ratchet effect. When the force is symmetric under time-reversal and the system is undamped, under symmetry principles no ratchet effect is possible. In this situation increasing damping generates a ratchet current which, upon increasing the damping coefficient eventually reaches a maximum and decreases toward zero. We argue that this effect is not specific of this example and should appear in any ratchet system with tunable damping driven by a time-reversible external force. (paper)

  20. Ratchet effect on a relativistic particle driven by external forces

    International Nuclear Information System (INIS)

    Quintero, Niurka R; Alvarez-Nodarse, Renato; Cuesta, Jose A

    2011-01-01

    We study the ratchet effect of a damped relativistic particle driven by both asymmetric temporal bi-harmonic and time-periodic piecewise constant forces. This system can be formally solved for any external force, providing the ratchet velocity as a nonlinear functional of the driving force. This allows us to explicitly illustrate the functional Taylor expansion formalism recently proposed for this kind of systems. The Taylor expansion reveals particularly useful to obtain the shape of the current when the force is periodic, piecewise constant. We also illustrate the somewhat counterintuitive effect that introducing damping may induce a ratchet effect. When the force is symmetric under time-reversal and the system is undamped, under symmetry principles no ratchet effect is possible. In this situation increasing damping generates a ratchet current which, upon increasing the damping coefficient eventually reaches a maximum and decreases toward zero. We argue that this effect is not specific of this example and should appear in any ratchet system with tunable damping driven by a time-reversible external force. (paper)

  1. Role of motive forces for the spin torque transfer for nano-structures

    Science.gov (United States)

    Barnes, Stewart

    2009-03-01

    Despite an announced imminent commercial realization of spin transfer random access memory (SPRAM) the current theory evolved from that of Slonczewski [1,2] does not conserve energy. Barnes and Maekawa [3] have shown, in order correct this defect, forces which originate from the spin rather than the charge of an electron must be accounted for, this leading to the concept of spin-motive-forces (smf) which must appear in Faraday's law and which significantly modifies the theory for spin-valves and domain wall devices [4]. A multi-channel theory in which these smf's redirect the spin currents will be described. In nano-structures it is now well known that the Kondo effect is reflected by conductance peaks. In essence, the spin degrees of freedom are used to enhance conduction. In a system with nano-magnets and a Coulomb blockade [5] the similar spin channels can be the only means of effective conduction. This results in a smf which lasts for minutes and an enormous magneto-resistance [5]. This implies the possibility of ``single electron memory'' in which the magnetic state is switched by a single electron. [4pt] [1] J. C. Slonczewski, Current-Driven Excitation of Magnetic Multilayers J. Magn. Magn. Mater. 159, L1 (1996). [0pt] [2] Y. Tserkovnyak, A. Brataas, G. E. W. Bauer, and B. I. Halperin, Nonlocal magnetization dynamics in ferromagnetic heterostructures, Rev. Mod. Phys. 77, 1375 (2005). [0pt] [3] S. E. Barnes and S. Maekawa, Generalization of Faraday's Law to Include Nonconservative Spin Forces Phys. Rev. Lett. 98, 246601 (2007); S. E. Barnes and S. Maekawa, Currents induced by domain wall motion in thin ferromagnetic wires. arXiv:cond-mat/ 0410021v1 (2004). [0pt] [4] S. E., Barnes, Spin motive forces, measurement, and spin-valves. J. Magn. Magn. Mat. 310, 2035-2037 (2007); S. E. Barnes, J. Ieda. J and S. Maekawa, Magnetic memory and current amplification devices using moving domain walls. Appl. Phys. Lett. 89, 122507 (2006). [0pt] [5] Pham-Nam Hai, Byung-Ho Yu

  2. Spin motive forces, 'measurements', and spin-valves

    International Nuclear Information System (INIS)

    Barnes, S.E.

    2007-01-01

    Discussed is the spin motive force (smf) produced by a spin valve, this reflecting its dynamics. Relaxation implies an implicit measurement of the magnetization of the free layer of a valve. It is shown this has implications for the angular dependence of the torque transfer. Some discussion of recent experiments is included

  3. Degenerate four-wave mixing mediated by ponderomotive-force-driven plasma gratings

    International Nuclear Information System (INIS)

    Lee, K.-H.; Lin, M.-W.; Pai, C.-H.; Ha, L.-C.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

    2007-01-01

    Degenerate four-wave mixing mediated by ponderomotive-force-driven plasma gratings is demonstrated in the near-infrared regime. The quadratic dependence of the reflectivity of the probe pulse on plasma density indicates that the mixing is caused by the quasineutral plasma grating driven by the laser ponderomotive force. The experiment verifies that ponderomotive force is an effective means to produce a large-amplitude short-period plasma grating, which has many important applications in ultrahigh-intensity optics. In particular, such a grating is a crucial element for the development of plasma phase-conjugate mirrors that can be used to restore the wave-front distortion that is ubiquitous in nonlinear propagation

  4. Motive, desire, drive: the discourse of force

    Directory of Open Access Journals (Sweden)

    Alan Blum

    2013-12-01

    Full Text Available A review of the original paper on motive by Blum and McHugh (1971 is used as an occasion to make transparent an approach to social theory as it has developed over the years in their work. This method, in treating motive as an illustration, engages it as an example of the status of the signifier as a symptom of interpretive conflict endemic to any situation of action, always inviting an analysis of the symbolic order and imaginative structure that sustains the distinction as a force in social life. In this paper, motive in particular is unpacked to show how it serves as an indication of fundamental ambiguity with respect to a problem-solving situation, revealing in this case constant perplexity in relation to the enigmatic character of what comes to view on any occasion and the recurrent contestation that is released.

  5. A numerical study of microparticle acoustophoresis driven by acoustic radiation forces and streaming-induced drag forces

    DEFF Research Database (Denmark)

    Muller, Peter Barkholt; Barnkob, Rune; Jensen, Mads Jakob Herring

    2012-01-01

    We present a numerical study of the transient acoustophoretic motion of microparticles suspended in a liquid-filled microchannel and driven by the acoustic forces arising from an imposed standing ultrasound wave: the acoustic radiation force from the scattering of sound waves on the particles...

  6. Understanding parental motivators and barriers to uptake of child poison safety strategies: a qualitative study.

    Science.gov (United States)

    Gibbs, L; Waters, E; Sherrard, J; Ozanne-Smith, J; Robinson, J; Young, S; Hutchinson, A

    2005-12-01

    To develop an understanding of factors acting as barriers and motivators to parental uptake of child poison safety strategies. A qualitative study involving semistructured interviews and focus groups. A grounded theory approach was used for the collection and analysis of data. Sixty five parents of children under 5 years of age, some of whom had experienced an unintentional child poisoning incident. A range of knowledge based, environmental, and behavioral barriers to comprehensive parental uptake of poison safety practices were identified. As a result there tended to be only partial implementation of safety initiatives in the home. Selection of safety practices was often guided by the interests and behaviors of the child. This made the child vulnerable to changes in the home environment, inadequate supervision, and/or shifts in their own behavior and developmental ability. Personal or vicarious exposure of a parent to a child poisoning incident was a significant motivator for parental review of safety practices. Environmental measures targeting child resistant containers, warning labels, and lockable poisons cupboards will support parents' efforts to maintain poison safety. Additional education campaigns using stories of actual poisoning incidents may help to increase awareness of risk and encourage increased uptake.

  7. Identification of Motive Forces on the Whole Body System during Walking

    Directory of Open Access Journals (Sweden)

    Raghdan J. AlKhoury

    2010-01-01

    Full Text Available Motive forces by muscles are applied to different parts of the human body in a periodic fashion when walking at a uniform rate. In this study, the whole human body is modeled as a multidegree of freedom (MDOF system with seven degrees of freedom. In view of the changing contact conditions with the ground due to alternating feet movements, the system under study is considered piecewise time invariant for each half-period when one foot is in contact with the ground. Forces transmitted from the body to the ground while walking at a normal pace are experimentally measured and numerically simulated. Fourth-order Runge-Kutta method is employed to numerically simulate the forces acting on different masses of the body. An optimization problem is formulated with the squared difference between the measured and simulated forces transmitted to the ground as the objective function, and the motive forces on the body masses as the design variables to solve.

  8. Older adults' motivated choice for technological innovation: Evidence for benefit-driven selectivity

    NARCIS (Netherlands)

    Melenhorst, Anne-Sophie; Rogers, Wendy A.; Bouwhuis, Don G.

    2006-01-01

    This study examined older adults' motivation to adopt technological innovation. Sixty-eight older e-mail users and nonusers discussed the use of e-mail and of traditional communication methods in 18 focus groups. The results show older adults' benefit-driven approach to new communication technology.

  9. Older adults motivated choice for technological innovation: evidence for benefit-driven selectivity

    NARCIS (Netherlands)

    Melenhorst, A.S.; Rogers, W.A.; Bouwhuis, D.G.

    2006-01-01

    This study examined older adults' motivation to adopt technological innovation. Sixty-eight older e-mail users and nonusers discussed the use of e-mail and of traditional communication methods in 18 focus groups. The results show older adults' benefit-driven approach to new communication technology.

  10. Characterization of the selenite uptake mechanism in the coccolithophore Emiliania huxleyi (Haptophyta).

    Science.gov (United States)

    Araie, Hiroya; Sakamoto, Kou; Suzuki, Iwane; Shiraiwa, Yoshihiro

    2011-07-01

    The marine coccolithophore Emiliania huxleyi (Haptophyta) requires selenium as an essential element for growth, and the active species absorbed is selenite, not selenate. This study characterized the selenite uptake mechanism using ⁷⁵Se as a tracer. Kinetic analysis of selenite uptake showed the involvement of both active and passive transport processes. The active transport was suppressed by 0.5 mM vanadate, a membrane-permeable inhibitor of H⁺-ATPase, at pH 8.3. When the pH was lowered from 8.3 to 5.3, the selenite uptake activity greatly increased, even in the presence of vanadate, suggesting that the H⁺ concentration gradient may be a motive force for selenite transport. [⁷⁵Se]Selenite uptake at selenite-limiting concentrations was hardly affected by selenate, sulfate and sulfite, even at 100 μM. In contrast, 3 μM orthophosphate increased the K(m) 5-fold. These data showed that HSeO₃⁻, a dominant selenite species at acidic pH, is the active species for transport through the plasma membrane and transport is driven by ΔpH energized by H⁺-ATPase. Kinetic analysis showed that the selenite uptake activity was competitively inhibited by orthophosphate. Furthermore, the active selenite transport mechanism was shown to be induced de novo under Se-deficient conditions and induction was suppressed by the addition of either sufficient selenite or cycloheximide, an inhibitor of de novo protein synthesis. These results indicate that E. huxleyi cells developed an active selenite uptake mechanism to overcome the disadvantages of Se limitation in ecosystems, maintaining selenium metabolism and selenoproteins for high viability.

  11. A silicon-nanowire memory driven by optical gradient force induced bistability

    Energy Technology Data Exchange (ETDEWEB)

    Dong, B. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), Singapore 117685 (Singapore); Cai, H., E-mail: caih@ime.a-star.edu.sg; Gu, Y. D.; Kwong, D. L. [Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), Singapore 117685 (Singapore); Chin, L. K.; Ng, G. I.; Ser, W. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Huang, J. G. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), Singapore 117685 (Singapore); School of Mechanical Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Yang, Z. C. [School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Liu, A. Q., E-mail: eaqliu@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

    2015-12-28

    In this paper, a bistable optical-driven silicon-nanowire memory is demonstrated, which employs ring resonator to generate optical gradient force over a doubly clamped silicon-nanowire. Two stable deformation positions of a doubly clamped silicon-nanowire represent two memory states (“0” and “1”) and can be set/reset by modulating the light intensity (<3 mW) based on the optical force induced bistability. The time response of the optical-driven memory is less than 250 ns. It has applications in the fields of all optical communication, quantum computing, and optomechanical circuits.

  12. The effect of ac-driven force on superlubricity in a two-dimensional Frenkel-Kontorova model

    International Nuclear Information System (INIS)

    Lin Maimai

    2010-01-01

    By using the molecular dynamic simulation method with a fourth-order Runge-Kutta algorithm, a two-dimensional dc- and ac-driven Frenkel-Kontorova model with a square symmetry substrate potential for a square lattice layer has been investigated in this paper. For this system, the effects of many different parameters on the static friction force have been studied in detail. It was found that not only the amplitude and frequency of the ac-driven force, but also the direction of dc- and ac-driven forces and the misfit angle between two layers have a strong influence on the static friction force. This indicated that the phenomenon of superlubricity appears easily with larger ac amplitude and smaller ac frequency for some special direction of the external driving force and misfit angle.

  13. Impact Forces from Tsunami-Driven Debris

    Science.gov (United States)

    Ko, H.; Cox, D. T.; Riggs, H.; Naito, C. J.; Kobayashi, M. H.; Piran Aghl, P.

    2012-12-01

    Debris driven by tsunami inundation flow has been known to be a significant threat to structures, yet we lack the constitutive equations necessary to predict debris impact force. The objective of this research project is to improve our understanding of, and predictive capabilities for, tsunami-driven debris impact forces on structures. Of special interest are shipping containers, which are virtually everywhere and which will float even when fully loaded. The forces from such debris hitting structures, for example evacuation shelters and critical port facilities such as fuel storage tanks, are currently not known. This research project focuses on the impact by flexible shipping containers on rigid columns and investigated using large-scale laboratory testing. Full-scale in-air collision experiments were conducted at Lehigh University with 20 ft shipping containers to experimentally quantify the nonlinear behavior of full scale shipping containers as they collide into structural elements. The results from the full scale experiments were used to calibrate computer models and used to design a series of simpler, 1:5 scale wave flume experiments at Oregon State University. Scaled in-air collision tests were conducted using 1:5 scale idealized containers to mimic the container behavior observed in the full scale tests and to provide a direct comparison to the hydraulic model tests. Two specimens were constructed using different materials (aluminum, acrylic) to vary the stiffness. The collision tests showed that at higher speeds, the collision became inelastic as the slope of maximum impact force/velocity decreased with increasing velocity. Hydraulic model tests were conducted using the 1:5 scaled shipping containers to measure the impact load by the containers on a rigid column. The column was instrumented with a load cell to measure impact forces, strain gages to measure the column deflection, and a video camera was used to provide the debris orientation and speed. The

  14. Winds from accretion disks driven by the radiation and magnetocentrifugal force

    OpenAIRE

    Proga, D.

    2000-01-01

    We study the 2-D, time-dependent hydrodynamics of radiation-driven winds from luminous accretion disks threaded by a strong, large-scale, ordered magnetic field. The radiation force is due to spectral lines and is calculated using a generalized multidimensional formulation of the Sobolev approximation. The effects of the magnetic field are approximated by adding a force that emulates a magnetocentrifugal force. Our approach allows us to calculate disk winds when the magnetic field controls th...

  15. The Electromechanical Behavior of a Micro-Ring Driven by Traveling Electrostatic Force

    Science.gov (United States)

    Ye, Xiuqian; Chen, Yibao; Chen, Da-Chih; Huang, Kuo-Yi; Hu, Yuh-Chung

    2012-01-01

    There is no literature mentioning the electromechanical behavior of micro structures driven by traveling electrostatic forces. This article is thus the first to present the dynamics and stabilities of a micro-ring subjected to a traveling electrostatic force. The traveling electrostatic force may be induced by sequentially actuated electrodes which are arranged around the flexible micro-ring. The analysis is based on a linearized distributed model considering the electromechanical coupling effects between electrostatic force and structure. The micro-ring will resonate when the traveling speeds of the electrostatic force approach some critical speeds. The critical speeds are equal to the ratio of the natural frequencies to the wave number of the correlative natural mode of the ring. Apart from resonance, the ring may be unstable at some unstable traveling speeds. The unstable regions appear not only near the critical speeds, but also near some fractions of some critical speeds differences. Furthermore the unstable regions expand with increasing driving voltage. This article may lead to a new research branch on electrostatic-driven micro devices. PMID:22438705

  16. Quality Challenges in Transnational Higher Education under Profit-Driven Motives: The Vietnamese Experience

    Science.gov (United States)

    Nhan, Thi Thuy; Nguyen, Huu Cuong

    2018-01-01

    Among educational practices in the era of globalisation, developing countries are emerging with diverse representations of transnational collaboration. This paper investigates the operation and regulation of joint programs in Vietnam as a case study of higher education under the impact of profit-driven motives. It first reviews the trends,…

  17. Porters and neurotransmitter transporters

    NARCIS (Netherlands)

    Nelson, Nathan; Lill, H

    1994-01-01

    Uptake of neurotransmitters involves multiple transporters acting in different brain locations under different physiological conditions. The vesicular transporters are driven by a proton-motive force generated by a V-ATPase and their substrates are taken up via proton/substrate exchange. The plasma

  18. Stakeholder-Driven Quality Improvement: A Compelling Force for Clinical Practice Guidelines.

    Science.gov (United States)

    Rosenfeld, Richard M; Wyer, Peter C

    2018-01-01

    Clinical practice guideline development should be driven by rigorous methodology, but what is less clear is where quality improvement enters the process: should it be a priority-guiding force, or should it enter only after recommendations are formulated? We argue for a stakeholder-driven approach to guideline development, with an overriding goal of quality improvement based on stakeholder perceptions of needs, uncertainties, and knowledge gaps. In contrast, the widely used topic-driven approach, which often makes recommendations based only on randomized controlled trials, is driven by epidemiologic purity and evidence rigor, with quality improvement a downstream consideration. The advantages of a stakeholder-driven versus a topic-driven approach are highlighted by comparisons of guidelines for otitis media with effusion, thyroid nodules, sepsis, and acute bacterial rhinosinusitis. These comparisons show that stakeholder-driven guidelines are more likely to address the quality improvement needs and pressing concerns of clinicians and patients, including understudied populations and patients with multiple chronic conditions. Conversely, a topic-driven approach often addresses "typical" patients, based on research that may not reflect the needs of high-risk groups excluded from studies because of ethical issues or a desire for purity of research design.

  19. Microcontroller-driven fluid-injection system for atomic force microscopy.

    Science.gov (United States)

    Kasas, S; Alonso, L; Jacquet, P; Adamcik, J; Haeberli, C; Dietler, G

    2010-01-01

    We present a programmable microcontroller-driven injection system for the exchange of imaging medium during atomic force microscopy. Using this low-noise system, high-resolution imaging can be performed during this process of injection without disturbance. This latter circumstance was exemplified by the online imaging of conformational changes in DNA molecules during the injection of anticancer drug into the fluid chamber.

  20. Transport of D-xylose in Lactobacillus pentosus, Lactobacillus casei, and Lactobacillus plantarum: Evidence for a mechanism of facilitated diffusion via the phosphoenolpyruvate:mannose phosphotransferase system

    NARCIS (Netherlands)

    Chaillou, S.; Pouwels, P.H.; Postma, P.W.

    1999-01-01

    We have identified and characterized the D-xylose transport system of Lactobacillus pentosus. Uptake of D-xylose was not driven by the proton motive force generated by malolactic fermentation and required D-xylose metabolism. The kinetics of D-xylose transport were indicative of a low- affinity

  1. Particle force model effects in a shock-driven multiphase instability

    Science.gov (United States)

    Black, W. J.; Denissen, N.; McFarland, J. A.

    2018-05-01

    This work presents simulations on a shock-driven multiphase instability (SDMI) at an initial particle volume fraction of 1% with the addition of a suite of particle force models applicable in dense flows. These models include pressure-gradient, added-mass, and interparticle force terms in an effort to capture the effects neighboring particles have in non-dilute flow regimes. Two studies are presented here: the first seeks to investigate the individual contributions of the force models, while the second study focuses on examining the effect of these force models on the hydrodynamic evolution of a SDMI with various particle relaxation times (particle sizes). In the force study, it was found that the pressure gradient and interparticle forces have little effect on the instability under the conditions examined, while the added-mass force decreases the vorticity deposition and alters the morphology of the instability. The relaxation-time study likewise showed a decrease in metrics associated with the evolution of the SDMI for all sizes when the particle force models were included. The inclusion of these models showed significant morphological differences in both the particle and carrier species fields, which increased as particle relaxation times increased.

  2. Fabrication of high-aspect-ratio microstructures using dielectrophoresis-electrocapillary force-driven UV-imprinting

    International Nuclear Information System (INIS)

    Li, Xiangming; Shao, Jinyou; Tian, Hongmiao; Ding, Yucheng; Li, Xiangmeng

    2011-01-01

    We propose a novel method for fabricating high-aspect-ratio micro-/nano-structures by dielectrophoresis-electrocapillary force (DEP-ECF)-driven UV-imprinting. The force of DEP-ECF, acting on an air–liquid interface and an air–liquid–solid three-phase contact line, is generated by applying voltage between an electrically conductive mold and a substrate, and tends to pull the dielectric liquid (a UV-curable pre-polymer) into the mold micro-cavities. The existence of DEP-ECF is explained theoretically and demonstrated experimentally by the electrically induced reduction of the contact angle. Furthermore, DEP-ECF is proven to play a critical role in forcing the polymer to fill into the mold cavities by the real-time observation of the dynamic filling process. Using the DEP-ECF-driven UV-imprinting process, high-aspect-ratio polymer micro-/nano-structures (more than 10:1) are fabricated with high consistency. This patterning method can overcome the drawbacks of the mechanically induced mold deformation and position shift in conventional imprinting lithography and maximize the pattern uniformity which is usually poor in capillary force lithography

  3. An updated model for nitrate uptake modelling in plants. I. Functional component: cross-combination of flow–force interpretation of nitrate uptake isotherms, and environmental and in planta regulation of nitrate influx

    Science.gov (United States)

    Le Deunff, Erwan; Malagoli, Philippe

    2014-01-01

    Background and Aims In spite of major breakthroughs in the last three decades in the identification of root nitrate uptake transporters in plants and the associated regulation of nitrate transport activities, a simplified and operational modelling approach for nitrate uptake is still lacking. This is due mainly to the difficulty in linking the various regulations of nitrate transport that act at different levels of time and on different spatial scales. Methods A cross-combination of a Flow–Force approach applied to nitrate influx isotherms and experimentally determined environmental and in planta regulation is used to model nitrate in oilseed rape, Brassica napus. In contrast to ‘Enzyme–Substrate’ interpretations, a Flow–Force modelling approach considers the root as a single catalytic structure and does not infer hypothetical cellular processes among nitrate transporter activities across cellular layers in the mature roots. In addition, this approach accounts for the driving force on ion transport based on the gradient of electrochemical potential, which is more appropriate from a thermodynamic viewpoint. Key Results and Conclusions Use of a Flow–Force formalism on nitrate influx isotherms leads to the development of a new conceptual mechanistic basis to model more accurately N uptake by a winter oilseed rape crop under field conditions during the whole growth cycle. This forms the functional component of a proposed new structure–function mechanistic model of N uptake. PMID:24638820

  4. Anisotropic spin motive force in multi-layered Dirac fermion system, α-(BEDT-TTF)2I3

    International Nuclear Information System (INIS)

    Kubo, K; Morinari, T

    2015-01-01

    We investigate the anisotropic spin motive force in α-(BEDT-TTF) 2 I 3 , which is a multi-layered massless Dirac fermion system under pressure. Assuming the interlayer antiferromagnetic interaction and the interlayer anisotropic ferromagnetic interaction, we numerically examine the spin ordered state of the ground state using the steepest descent method. The anisotropic interaction leads to the anisotropic spin ordered state. We calculate the spin motive force produced by the anisotropic spin texture. The result quantitatively agrees with the experiment. (paper)

  5. [The motive force of evolution based on the principle of organismal adjustment evolution.].

    Science.gov (United States)

    Cao, Jia-Shu

    2010-08-01

    From the analysis of the existing problems of the prevalent theories of evolution, this paper discussed the motive force of evolution based on the knowledge of the principle of organismal adjustment evolution to get a new understanding of the evolution mechanism. In the guide of Schrodinger's theory - "life feeds on negative entropy", the author proposed that "negative entropy flow" actually includes material flow, energy flow and information flow, and the "negative entropy flow" is the motive force for living and development. By modifying my own theory of principle of organismal adjustment evolution (not adaptation evolution), a new theory of "regulation system of organismal adjustment evolution involved in DNA, RNA and protein interacting with environment" is proposed. According to the view that phylogenetic development is the "integral" of individual development, the difference of negative entropy flow between organisms and environment is considered to be a motive force for evolution, which is a new understanding of the mechanism of evolution. Based on such understanding, evolution is regarded as "a changing process that one subsystem passes all or part of its genetic information to the next generation in a larger system, and during the adaptation process produces some new elements, stops some old ones, and thereby lasts in the larger system". Some other controversial questions related to evolution are also discussed.

  6. Robust non-local effects of ocean heat uptake on radiative feedback and subtropical cloud cover

    Science.gov (United States)

    Rose, B. E. J.

    2016-02-01

    Much recent work has pointed to the limitations of the global mean planetary energy budget as a useful diagnostic tool for understanding transient climate response, because the climate sensitivity (or radiative feedback) governing the relationships between ocean heat content, surface temperature and top-of-atmosphere energy imbalance depends sensitively on timescale, spatial pattern and nature of the climate forcing. Progress has been made by treating the slowly-evolving (and spatially complex) pattern of ocean heat uptake as a quasi-equilibrium forcing on the "fast" components of the climate system: the atmospheric radiative-dynamical processes that link air-sea heat exchange to the top-of-atmosphere energy budget. Differences between these feedbacks and those on CO2 radiative forcing can be expressed as an "efficacy" of ocean heat uptake. We use idealized slab ocean GCMs forced by prescribed steady energy sinks limited to specific latitude bands (representing heat exchange with the deep ocean) to quantify how (and why) the efficacy depends on the spatial pattern of ocean heat uptake. By repeating the experiment across several independent GCMs we identify robust and non-robust aspects of the response. We find that the efficacy of sub-polar heat uptake is 3 to 4 times larger than the efficacy of tropical heat uptake. Radiative kernel analysis allows an accurate partition into feedbacks due to temperature, water vapor and clouds. We find large and robust differences in clear-sky lapse rate feedbacks, associated with robust differences in large-scale atmospheric circulation and stratification driven by ocean heat uptake. A more novel and surprising result is the robustness across several independent GCMs of the differences in subtropical low cloud feedback (positive under high-latitude uptake, strongly negative under tropical uptake). We trace these robust differences to thermodynamic constraints associated with lower-tropospheric stability and boundary layer

  7. Mammography Screening Uptake among Female Health Care Workers in Primary Health Care Centers in Palestine - Motivators and Barriers.

    Science.gov (United States)

    Nazzal, Zaher; Sholi, Hisham; Sholi, Suha; Sholi, Mohammad; Lahaseh, Rawya

    2016-01-01

    Early detection remains the cornerstone of breast cancer control in terms of outcome and survival. Thus far the only breast cancer screening method proven effective is mammography. The awareness of female health care workers (HCW) about breast cancer prevention is of vital importance, as their beliefs and behavior may have a major impact on other women. This study was designed to assess mammography screening uptake among female healthcare workers at primary healthcare centers, and to identify the primary motivators and barriers that affect uptake results. A cross sectional study design was used to assess mammography screening by 299 female healthcare workers who completed a self-administered questionnaire that assessed demographics, screening uptake, motivators and barriers. The mean age was 46 years (within age of risk). The majority (95.1%) demonstrated adequate knowledge about breast cancer and mammography screening and 50% of the participants reported having at least one mammogram; however only 21% of them had regularly scheduled mammograms. The most frequent reported motivator was the perceived benefit that early detection of breast cancer is important for its management (89.6%), followed by the belief that mammography can detect breast cancer before its symptoms appear (84.4%). On the other hand, the most frequent barrier reported was being busy (46.7%), followed by the lack of perceived susceptibility (41.5%). Mammography screening was found to be sub-optimal in a population of HCW's with 50 % stating that they received a mammogram at least once, and a minority reported regular screening. There is a pressing need for educational programs aimed at removing the barriers that limit compliance with recommendations for mammography screening, and to emphasize the importance of early detection in breast cancer treatment. Ensuring the availability and accessibility of screening services, particularly for healthcare workers within their work settings are other

  8. Predicting influenza vaccination uptake among health care workers: what are the key motivators?

    Science.gov (United States)

    Corace, Kimberly; Prematunge, Chatura; McCarthy, Anne; Nair, Rama C; Roth, Virginia; Hayes, Thomas; Suh, Kathryn N; Balfour, Louise; Garber, Gary

    2013-08-01

    Health care worker (HCW) vaccination was critical to protecting HCW during the H1N1 pandemic. However, vaccine uptake rates fell below recommended targets. This study examined motivators and barriers influencing HCW pH1N1 vaccination to identify modifiable factors that can improve influenza vaccine uptake. A cross-sectional survey was conducted at a large Canadian tertiary care hospital. HCW (N = 3,275) completed measures of demographics, vaccination history, influenza risk factors, and attitudes toward pH1N1 vaccination. Self-reported vaccination was verified with staff vaccination records. Of the total sample, 2,862 (87.4%) HCW received the pH1N1 vaccine. Multiple logistic regression analyses were used to predict HCW vaccination. HCW attitudes toward vaccination significantly predicted vaccination, even after adjusting for demographics, vaccine history, and influenza risk factors. This model correctly predicted 95% (confidence interval [CI]: 0.93-0.96) of HCW vaccination. Key modifiable factors driving HCW vaccination include (1) desire to protect family members and patients, (2) belief that vaccination is important even if one is healthy, (3) confidence in vaccine safety, and (4) supervisor and physician encouragement. This research identified fundamental reasons why HCW get vaccinated and provides direction for future influenza vaccination programs. To enhance vaccine uptake, it is important to target HCW attitudes in influenza vaccine campaigns and create a culture of vaccine promotion in the workplace, including strong messaging from supervisors and physicians. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  9. A Descriptive Model of Patient Readiness, Motivators, and Hepatitis C Treatment Uptake among Australian Prisoners

    Science.gov (United States)

    Yap, Lorraine; Carruthers, Susan; Thompson, Sandra; Cheng, Wendy; Jones, Jocelyn; Simpson, Paul; Richards, Alun; Thein, Hla-Hla; Haber, Paul; Lloyd, Andrew; Butler, Tony

    2014-01-01

    Background Hepatitis C virus infection (HCV) has a significant global health burden with an estimated 2%–3% of the world's population infected, and more than 350,000 dying annually from HCV-related conditions including liver failure and liver cancer. Prisons potentially offer a relatively stable environment in which to commence treatment as they usually provide good access to health care providers, and are organised around routine and structure. Uptake of treatment of HCV, however, remains low in the community and in prisons. In this study, we explored factors affecting treatment uptake inside prisons and hypothesised that prisoners have unique issues influencing HCV treatment uptake as a consequence of their incarceration which are not experienced in other populations. Method and Findings We undertook a qualitative study exploring prisoners' accounts of why they refused, deferred, delayed or discontinued HCV treatment in prison. Between 2010 and 2013, 116 Australian inmates were interviewed from prisons in New South Wales, Queensland, and Western Australia. Prisoners experienced many factors similar to those which influence treatment uptake of those living with HCV infection in the community. Incarceration, however, provides different circumstances of how these factors are experienced which need to be better understood if the number of prisoners receiving treatment is to be increased. We developed a descriptive model of patient readiness and motivators for HCV treatment inside prisons and discussed how we can improve treatment uptake among prisoners. Conclusion This study identified a broad and unique range of challenges to treatment of HCV in prison. Some of these are likely to be diminished by improving treatment options and improved models of health care delivery. Other barriers relate to inmate understanding of their illness and stigmatisation by other inmates and custodial staff and generally appear less amenable to change although there is potential for

  10. A descriptive model of patient readiness, motivators, and hepatitis C treatment uptake among Australian prisoners.

    Directory of Open Access Journals (Sweden)

    Lorraine Yap

    Full Text Available BACKGROUND: Hepatitis C virus infection (HCV has a significant global health burden with an estimated 2%-3% of the world's population infected, and more than 350,000 dying annually from HCV-related conditions including liver failure and liver cancer. Prisons potentially offer a relatively stable environment in which to commence treatment as they usually provide good access to health care providers, and are organised around routine and structure. Uptake of treatment of HCV, however, remains low in the community and in prisons. In this study, we explored factors affecting treatment uptake inside prisons and hypothesised that prisoners have unique issues influencing HCV treatment uptake as a consequence of their incarceration which are not experienced in other populations. METHOD AND FINDINGS: We undertook a qualitative study exploring prisoners' accounts of why they refused, deferred, delayed or discontinued HCV treatment in prison. Between 2010 and 2013, 116 Australian inmates were interviewed from prisons in New South Wales, Queensland, and Western Australia. Prisoners experienced many factors similar to those which influence treatment uptake of those living with HCV infection in the community. Incarceration, however, provides different circumstances of how these factors are experienced which need to be better understood if the number of prisoners receiving treatment is to be increased. We developed a descriptive model of patient readiness and motivators for HCV treatment inside prisons and discussed how we can improve treatment uptake among prisoners. CONCLUSION: This study identified a broad and unique range of challenges to treatment of HCV in prison. Some of these are likely to be diminished by improving treatment options and improved models of health care delivery. Other barriers relate to inmate understanding of their illness and stigmatisation by other inmates and custodial staff and generally appear less amenable to change although there

  11. Citrate and succinate uptake by potato mitochondria

    International Nuclear Information System (INIS)

    Jung, D.W.; Laties, G.G.

    1979-01-01

    Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

  12. The proton motive force generated in Leuconostoc oenos by L-malate fermentation

    NARCIS (Netherlands)

    Salema, Madalena; Lolkema, Juke S.; San Romão, M.V.; Loureiro Dias, Maria C.

    In cells of Leuconostoc oenos, the fermentation of L-malic acid generates both a transmembrane pH gradient, inside alkaline, and an electrical potential gradient, inside negative. In resting cells, the proton motive force ranged from -170 mV to -88 mV between pH 3.1 and 5.6 in the presence of

  13. Kinetics of pyrophosphate-driven proton uptake by acidocalcisomes of Leptomonas wallacei

    International Nuclear Information System (INIS)

    Moraes Moreira, Bernardo Luiz; Soares Medeiros, Lia Carolina A.; Miranda, Kildare; Souza, Wanderley de; Hentschel, Joachim; Plattner, Helmut; Barrabin, Hector

    2005-01-01

    In this work, we show the kinetics of pyrophosphate-driven H + uptake by acidocalcisomes in digitonin-permeabilized promastigotes of Leptomonas wallacei. The vacuolar proton pyrophosphatase activity was optimal in the pH range of 7.5-8.0, was inhibited by imidiodiphosphate, and was completely dependent on K + and PPi. H + was released with the addition of Ca 2+ , suggesting the presence of a Ca 2+ /H + antiport. In addition, X-ray elemental mapping associated with energy-filtering transmission electron microscopy showed that most of the Ca, Na, Mg, P, K, Fe, and Zn were located in acidocalcisomes. L. wallacei immunolabeled with antibodies against Trypanosoma cruzi pyrophosphatase show intense fluorescence in cytoplasmatic organelles of size and distribution similar to the acidocalcisomes. Altogether, the results show that L. wallacei acidocalcisomes possess a H + -pyrophosphatase with characteristics of type I V-H + -PPase. However, we did not find any evidence, either for the presence of H + -ATPases or for Na + /H + exchangers in these acidocalcisomes

  14. Engineering flow states with localized forcing in a thin Marangoni-driven inclined film.

    Science.gov (United States)

    Levy, Rachel; Rosenthal, Stephen; Wong, Jeffrey

    2010-11-01

    Numerical simulations of lubrication models provide clues for experimentalists about the development of wave structures in thin liquid films. We analyze numerical simulations of a lubrication model for an inclined thin liquid film modified by Marangoni forces due to a thermal gradient and additional localized forcing heating the substrate. Numerical results can be explained through connections to theory for hyperbolic conservation laws predicting wave fronts from Marangoni-driven thin films without forcing. We demonstrate how a variety of forcing profiles, such as gaussian, rectangular, and triangular, affect the formation of downstream transient structures, including an N wave not commonly discussed in the context of thin films. Simulations employing a controlled approximation of a compressive-undercompressive wave pair demonstrate possibilities for applications of localized forcing as microfluidic valve. In the simulations, localized forcing provides a control parameter that can be used to determine mass flux and film profiles.

  15. Uncertainties in carbon residence time and NPP-driven carbon uptake in terrestrial ecosystems of the conterminous USA: a Bayesian approach

    Directory of Open Access Journals (Sweden)

    Xuhui Zhou

    2012-10-01

    Full Text Available Carbon (C residence time is one of the key factors that determine the capacity of ecosystem C storage. However, its uncertainties have not been well quantified, especially at regional scales. Assessing uncertainties of C residence time is thus crucial for an improved understanding of terrestrial C sequestration. In this study, the Bayesian inversion and Markov Chain Monte Carlo (MCMC technique were applied to a regional terrestrial ecosystem (TECO-R model to quantify C residence times and net primary productivity (NPP-driven ecosystem C uptake and assess their uncertainties in the conterminous USA. The uncertainty was represented by coefficient of variation (CV. The 13 spatially distributed data sets of C pools and fluxes have been used to constrain TECO-R model for each biome (totally eight biomes. Our results showed that estimated ecosystem C residence times ranged from 16.6±1.8 (cropland to 85.9±15.3 yr (evergreen needleleaf forest with an average of 56.8±8.8 yr in the conterminous USA. The ecosystem C residence times and their CV were spatially heterogeneous and varied with vegetation types and climate conditions. Large uncertainties appeared in the southern and eastern USA. Driven by NPP changes from 1982 to 1998, terrestrial ecosystems in the conterminous USA would absorb 0.20±0.06 Pg C yr−1. Their spatial pattern was closely related to the greenness map in the summer with larger uptake in central and southeast regions. The lack of data or timescale mismatching between the available data and the estimated parameters lead to uncertainties in the estimated C residence times, which together with initial NPP resulted in the uncertainties in the estimated NPP-driven C uptake. The Bayesian approach with MCMC inversion provides an effective tool to estimate spatially distributed C residence time and assess their uncertainties in the conterminous USA.

  16. Motivators and barriers to mammography screening uptake by female health-care workers in primary health-care centres: a cross-sectional study.

    Science.gov (United States)

    Nazzal, Zaher; Sholi, Hisham; Sholi, Suha B; Sholi, Mohammad B; Lahaseh, Rawya

    2018-02-21

    Mammography screening is an effective tool for early detection and management of breast cancer. Female health-care workers' awareness of breast cancer screening is important because their beliefs and behaviours could influence other women. The aim of this study was to assess mammography screening uptake by female health-care workers at primary health-care centres and to identify the primary motivators and barriers that affect uptake. This cross-sectional study included all governmental primary health-care centres in the West Bank. Governorates were grouped into three regions as follows: north West Bank (Nablus, Jenin, Tulkarm, Tubas, Qalqiliya, and Salfit), middle West Bank (Jerusalem, Jericho, and Ramallah), and south West Bank (Hebron, and Bethlehem). The study population included all female health-care workers older than 40 years. Those who performed mammography for a suspected mass or other breast abnormalities were excluded. A self-administered questionnaire was used to collect data on demographic characteristics, knowledge about mammography screening, the extent and regularity of mammography screening, and motivators and barriers influencing their mammography screening uptake. The rate of mammography screening uptake was calculated. χ 2 test and t tests were used to assess screening motivators and barriers. The study was approved by the Institutional Review Board of the An-Najah National University. Participation was voluntary, and written consent was obtained from each participant. 299 female health-care workers completed a self-administered questionnaire. The mean age of the participants was 46 years (SD 4·7). 284 (95%) women had adequate knowledge about breast cancer and mammography screening, and 149 (50%) women reported having had at least one mammogram. 62 (21%) women had had regular scheduled mammograms. The most frequent reported motivators were the perceived benefit that early detection of breast cancer is important for its management (269 [90

  17. Direct uptake of canopy rainwater causes turgor-driven growth spurts in the mangrove Avicennia marina.

    Science.gov (United States)

    Steppe, Kathy; Vandegehuchte, Maurits W; Van de Wal, Bart A E; Hoste, Pieter; Guyot, Adrien; Lovelock, Catherine E; Lockington, David A

    2018-03-17

    Mangrove forests depend on a dense structure of sufficiently large trees to fulfil their essential functions as providers of food and wood for animals and people, CO2 sinks and protection from storms. Growth of these forests is known to be dependent on the salinity of soil water, but the influence of foliar uptake of rainwater as a freshwater source, additional to soil water, has hardly been investigated. Under field conditions in Australia, stem diameter variation, sap flow and stem water potential of the grey mangrove (Avicennia marina (Forssk.) Vierh.) were simultaneously measured during alternating dry and rainy periods. We found that sap flow in A. marina was reversed, from canopy to roots, during and shortly after rainfall events. Simultaneously, stem diameters rapidly increased with growth rates up to 70 μm h-1, which is about 25-75 times the normal growth rate reported in temperate trees. A mechanistic tree model was applied to provide evidence that A. marina trees take up water through their leaves, and that this water contributes to turgor-driven stem growth. Our results indicate that direct uptake of freshwater by the canopy during rainfall supports mangrove tree growth and serve as a call to consider this water uptake pathway if we aspire to correctly assess influences of changing rainfall patterns on mangrove tree growth.

  18. Motivating forces of human actions. Neuroimaging reward and social interaction.

    Science.gov (United States)

    Walter, Henrik; Abler, Birgit; Ciaramidaro, Angela; Erk, Susanne

    2005-11-15

    In neuroeconomics, reward and social interaction are central concepts to understand what motivates human behaviour. Both concepts are investigated in humans using neuroimaging methods. In this paper, we provide an overview about these results and discuss their relevance for economic behaviour. For reward it has been shown that a system exists in humans that is involved in predicting rewards and thus guides behaviour, involving a circuit including the striatum, the orbitofrontal cortex and the amygdala. Recent studies on social interaction revealed a mentalizing system representing the mental states of others. A central part of this system is the medial prefrontal cortex, in particular the anterior paracingulate cortex. The reward as well as the mentalizing system is engaged in economic decision-making. We will discuss implications of this study for neuromarketing as well as general implications of these results that may help to provide deeper insights into the motivating forces of human behaviour.

  19. A repulsive magnetic force driven translation micromirror

    International Nuclear Information System (INIS)

    Xue, Yuan; Zuo, Hui; He, Siyuan

    2017-01-01

    This paper presents a repulsive magnetic force driven micromirror with large displacement and high surface quality which well solves the limitation of the previous design, i.e. large variation in translation starting position and low repeatability, caused by the touching points between the moving film and substrate before and in operation. The new design utilizes a driving mechanism, i.e. permanent magnet ring above and electromagnet underneath the moving film, to lift the moving film from touching the substrate and generate a repulsive magnetic force (instead of attractive force in the previous design) to push the moving film up and away from the substrate for translation. Due to the touching, the previous design has to pre-oscillate for 20–30 min at 1 Hz before usage (after resting for a few hours) to reduce the starting position variation from ∼15 µ m to 3–4 µ m. Even after the pre-oscillation, the repeatability is still low, which is 14.2% because of the touching in operation. In the design presented in this paper, the touching between the moving film and the substrate is completely eliminated before and in operation. As a result, the starting position of the translating mirror is constant each time and the repeatability is  <1%. In addition, this design does not need the residual stress gradient to curve up the moving film. The maximum displacement of 144 µ m can be achieved when 140 mA current is applied on the electromagnet. As an application, the micromirror is used as the movable mirror in a Michelson interferometer to measure the wavelength of a laser beam. The result shows a measurement accuracy of 2.19% for a 532 nm laser beam. (paper)

  20. A repulsive magnetic force driven translation micromirror

    Science.gov (United States)

    Xue, Yuan; Zuo, Hui; He, Siyuan

    2017-10-01

    This paper presents a repulsive magnetic force driven micromirror with large displacement and high surface quality which well solves the limitation of the previous design, i.e. large variation in translation starting position and low repeatability, caused by the touching points between the moving film and substrate before and in operation. The new design utilizes a driving mechanism, i.e. permanent magnet ring above and electromagnet underneath the moving film, to lift the moving film from touching the substrate and generate a repulsive magnetic force (instead of attractive force in the previous design) to push the moving film up and away from the substrate for translation. Due to the touching, the previous design has to pre-oscillate for 20-30 min at 1 Hz before usage (after resting for a few hours) to reduce the starting position variation from ~15 µm to 3-4 µm. Even after the pre-oscillation, the repeatability is still low, which is 14.2% because of the touching in operation. In the design presented in this paper, the touching between the moving film and the substrate is completely eliminated before and in operation. As a result, the starting position of the translating mirror is constant each time and the repeatability is  <1%. In addition, this design does not need the residual stress gradient to curve up the moving film. The maximum displacement of 144 µm can be achieved when 140 mA current is applied on the electromagnet. As an application, the micromirror is used as the movable mirror in a Michelson interferometer to measure the wavelength of a laser beam. The result shows a measurement accuracy of 2.19% for a 532 nm laser beam.

  1. Perspectives on continuum flow models for force-driven nano-channel liquid flows

    Science.gov (United States)

    Beskok, Ali; Ghorbanian, Jafar; Celebi, Alper

    2017-11-01

    A phenomenological continuum model is developed using systematic molecular dynamics (MD) simulations of force-driven liquid argon flows confined in gold nano-channels at a fixed thermodynamic state. Well known density layering near the walls leads to the definition of an effective channel height and a density deficit parameter. While the former defines the slip-plane, the latter parameter relates channel averaged density with the desired thermodynamic state value. Definitions of these new parameters require a single MD simulation performed for a specific liquid-solid pair at the desired thermodynamic state and used for calibration of model parameters. Combined with our observations of constant slip-length and kinematic viscosity, the model accurately predicts the velocity distribution and volumetric and mass flow rates for force-driven liquid flows in different height nano-channels. Model is verified for liquid argon flow at distinct thermodynamic states and using various argon-gold interaction strengths. Further verification is performed for water flow in silica and gold nano-channels, exhibiting slip lengths of 1.2 nm and 15.5 nm, respectively. Excellent agreements between the model and the MD simulations are reported for channel heights as small as 3 nm for various liquid-solid pairs.

  2. Older adults' motivated choice for technological innovation: evidence for benefit-driven selectivity.

    Science.gov (United States)

    Melenhorst, Anne-Sophie; Rogers, Wendy A; Bouwhuis, Don G

    2006-03-01

    This study examined older adults' motivation to adopt technological innovation. Sixty-eight older e-mail users and nonusers discussed the use of e-mail and of traditional communication methods in 18 focus groups. The results show older adults' benefit-driven approach to new communication technology. Regardless of whether their decision about the new technology was positive or negative and irrespective of their e-mail experience, participants focused on benefits rather than costs. For traditional media, both costs and benefits were important. Results contradict the common belief that barriers such as usability problems determine whether older people use new technology and indicate the decisive role of perceived benefits for successful innovation. ((c) 2006 APA, all rights reserved).

  3. Pattern formation, social forces, and diffusion instability in games with success-driven motion

    Science.gov (United States)

    Helbing, Dirk

    2009-02-01

    A local agglomeration of cooperators can support the survival or spreading of cooperation, even when cooperation is predicted to die out according to the replicator equation, which is often used in evolutionary game theory to study the spreading and disappearance of strategies. In this paper, it is shown that success-driven motion can trigger such local agglomeration and may, therefore, be used to supplement other mechanisms supporting cooperation, like reputation or punishment. Success-driven motion is formulated here as a function of the game-theoretical payoffs. It can change the outcome and dynamics of spatial games dramatically, in particular as it causes attractive or repulsive interaction forces. These forces act when the spatial distributions of strategies are inhomogeneous. However, even when starting with homogeneous initial conditions, small perturbations can trigger large inhomogeneities by a pattern-formation instability, when certain conditions are fulfilled. Here, these instability conditions are studied for the prisoner’s dilemma and the snowdrift game. Furthermore, it is demonstrated that asymmetrical diffusion can drive social, economic, and biological systems into the unstable regime, if these would be stable without diffusion.

  4. A data-driven decomposition approach to model aerodynamic forces on flapping airfoils

    Science.gov (United States)

    Raiola, Marco; Discetti, Stefano; Ianiro, Andrea

    2017-11-01

    In this work, we exploit a data-driven decomposition of experimental data from a flapping airfoil experiment with the aim of isolating the main contributions to the aerodynamic force and obtaining a phenomenological model. Experiments are carried out on a NACA 0012 airfoil in forward flight with both heaving and pitching motion. Velocity measurements of the near field are carried out with Planar PIV while force measurements are performed with a load cell. The phase-averaged velocity fields are transformed into the wing-fixed reference frame, allowing for a description of the field in a domain with fixed boundaries. The decomposition of the flow field is performed by means of the POD applied on the velocity fluctuations and then extended to the phase-averaged force data by means of the Extended POD approach. This choice is justified by the simple consideration that aerodynamic forces determine the largest contributions to the energetic balance in the flow field. Only the first 6 modes have a relevant contribution to the force. A clear relationship can be drawn between the force and the flow field modes. Moreover, the force modes are closely related (yet slightly different) to the contributions of the classic potential models in literature, allowing for their correction. This work has been supported by the Spanish MINECO under Grant TRA2013-41103-P.

  5. A Novel Sensorless Control Strategy for Brushless Direct Current Motor Based on the Estimation of Line Back Electro-Motive Force

    Directory of Open Access Journals (Sweden)

    Chengde Tong

    2017-09-01

    Full Text Available In this paper, a novel sensorless control strategy based on the estimation of line back electro-motive force (BEMF is proposed. According to the phase relationship between the ideal commutation points of the brushless direct current motor (BLDCM and the zero-crossing points (ZCPs of the line BEMF, the calculation formula of line BEMF is simplified properly and the commutation rule for different positions of the rotor is presented. The estimation error of line BEMF caused by the freewheeling current of silent phase is analyzed, and the solution is given. With the phase shift of the low-pass filter considered, a compensation method using “60°-α” and “120°-α” is studied in this paper to eliminate the error. Finally, the simulation and experimental results show that the rotor-position-detection error is reduced effectively and the motor driven by the accurate commutation signal can work well at low and high speed.

  6. Depletion of proton motive force by nisin in Listeria monocytogenes cells.

    OpenAIRE

    Bruno, M E; Kaiser, A; Montville, T J

    1992-01-01

    The basal proton motive force (PMF) levels and the influence of the bacteriocin nisin on the PMF were determined in Listeria monocytogenes Scott A. In the absence of nisin, the interconversion of the pH gradient (Z delta pH) and the membrane potential (delta psi) led to the maintenance of a fairly constant PMF at -160 mV over the external pH range 5.5 to 7.0. The addition of nisin at concentrations of greater than or equal to 5 micrograms/ml completely dissipated PMF in cells at external pH v...

  7. Intrinsic non-inductive current driven by ETG turbulence in tokamaks

    Science.gov (United States)

    Singh, Rameswar; Kaw, P. K.; Singh, R.; Gürcan, Ã.-. D.

    2017-10-01

    Motivated by observations and physics understanding of the phenomenon of intrinsic rotation, it is suggested that similar considerations for electron dynamics may result in intrinsic current in tokamaks. We have investigated the possibility of intrinsic non-inductive current in the turbulent plasma of tokamaks. Ohm's law is generalized to include the effect of turbulent fluctuations in the mean field approach. This clearly leads to the identification of sources and the mechanisms of non-inductive current drive by electron temperature gradient turbulence. It is found that a mean parallel electro-motive force and hence a mean parallel current can be generated by (1) the divergence of residual current flux density and (2) a non-flux like turbulent source from the density and parallel electric field correlations. Both residual flux and the non-flux source require parallel wave-number k∥ symmetry breaking for their survival which can be supplied by various means like mean E × B shear, turbulence intensity gradient, etc. Estimates of turbulence driven current are compared with the background bootstrap current in the pedestal region. It is found that turbulence driven current is nearly 10% of the bootstrap current and hence can have a significant influence on the equilibrium current density profiles and current shear driven modes.

  8. Anabolic steroid use and body image psychopathology in men: Delineating between appearance- versus performance-driven motivations.

    Science.gov (United States)

    Murray, Stuart B; Griffiths, Scott; Mond, Jonathan M; Kean, Joseph; Blashill, Aaron J

    2016-08-01

    Anabolic androgenic steroid (AAS) use has been robustly associated with negative body image, and eating- and muscularity-oriented psychopathology. However, with AAS being increasingly utilized for both appearance and athletic performance-related purposes, we investigated whether comorbid body image psychopathology varies as a function of motivation for usage. Self-reported motivation for current and initial AAS use was recorded amongst 122 AAS using males, alongside measures of current disordered eating and muscle dysmorphia psychopathology. Those reporting AAS for appearance purposes reported greater overall eating disorder psychopathology, F(2, 118)=7.45, p=0.001, ηp(2)=0.11, and muscle dysmorphia psychopathology, F(2, 118)=7.22, ppsychopathology amongst users. Men whose AAS use is driven primarily by appearance-related concerns may be a particularly dysfunctional subgroup. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Cell wall-bound silicon optimizes ammonium uptake and metabolism in rice cells.

    Science.gov (United States)

    Sheng, Huachun; Ma, Jie; Pu, Junbao; Wang, Lijun

    2018-05-16

    Turgor-driven plant cell growth depends on cell wall structure and mechanics. Strengthening of cell walls on the basis of an association and interaction with silicon (Si) could lead to improved nutrient uptake and optimized growth and metabolism in rice (Oryza sativa). However, the structural basis and physiological mechanisms of nutrient uptake and metabolism optimization under Si assistance remain obscure. Single-cell level biophysical measurements, including in situ non-invasive micro-testing (NMT) of NH4+ ion fluxes, atomic force microscopy (AFM) of cell walls, and electrolyte leakage and membrane potential, as well as whole-cell proteomics using isobaric tags for relative and absolute quantification (iTRAQ), were performed. The altered cell wall structure increases the uptake rate of the main nutrient NH4+ in Si-accumulating cells, whereas the rate is only half in Si-deprived counterparts. Rigid cell walls enhanced by a wall-bound form of Si as the structural basis stabilize cell membranes. This, in turn, optimizes nutrient uptake of the cells in the same growth phase without any requirement for up-regulation of transmembrane ammonium transporters. Optimization of cellular nutrient acquisition strategies can substantially improve performance in terms of growth, metabolism and stress resistance.

  10. Molecular Dynamics Simulations of a Linear Nanomotor Driven by Thermophoretic Forces

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard L.

    Molecular Dynamics of a Linear Nanomotor Driven by Thermophoresis Harvey A. Zambrano1, Jens H. Walther1,2 and Richard L. Jaffe3 1Department of Mechanical Engineering, Fluid Mechanics, Technical University of Denmark, DK-2800 Lyngby, Denmark; 2Computational Science and Engineering Laboratory, ETH...... future molecular machines a complete understanding of the friction forces involved on the transport process at the molecular level have to be addressed.18 In this work we perform Molecular Dynamics (MD) simulations using the MD package FASTTUBE19 to study a molecular linear motor consisting of coaxial...... the valence forces within the CNT using Morse, harmonic angle and torsion potentials.19We include a nonbonded carbon-carbon Lennard-Jones potential to describe the vdW interaction between the carbon atoms within the double wall portion of the system. We equilibrate the system at 300K for 0.1 ns, by coupling...

  11. Magnetic force driven magnetoelectric effect in bi-cantilever composites

    Science.gov (United States)

    Zhang, Ru; Wu, Gaojian; Zhang, Ning

    2017-12-01

    The magnetic force driven magnetoelectric (ME) effect in bi-cantilever Mn-Zn-Ferrite /PZT composites is presented. Compared with single cantilever, the ME voltage coefficient in bi-cantilever composite is a little lower and the resonance frequency is higher, but the bi-cantilever structure is advantageous for integration. When the magnetic gap is 3 mm, the ME voltage coefficient can achieve 6.2 Vcm-1Oe-1 at resonance under optimum bias field Hm=1030 Oe; when the magnetic gap is 1.5 mm, the ME voltage coefficient can get the value as high as 4.4 Vcm-1Oe-1 under much lower bias field H=340 Oe. The stable ME effect in bi-cantilever composites has important potential application in the design of new type ME device.

  12. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    International Nuclear Information System (INIS)

    Kim, S H; Hashi, S; Ishiyama, K

    2011-01-01

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and 19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  13. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    Science.gov (United States)

    Kim, S. H.; Hashi, S.; Ishiyama, K.

    2011-01-01

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  14. Neuroscientific Model of Motivational Process

    OpenAIRE

    Kim, Sung-il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Rewa...

  15. Nisin depletes ATP and proton motive force in mycobacteria.

    Science.gov (United States)

    Chung, H J; Montville, T J; Chikindas, M L

    2000-12-01

    This study examined the inhibitory effect of nisin and its mode of action against Mycobacterium smegmatis, a non-pathogenic species of mycobacteria, and M. bovis-Bacill Carmette Guerin (BCG), a vaccine strain of pathogenic M. bovis. In agar diffusion assays, 2.5 mg ml(-1) nisin was required to inhibit M. bovis-BCG. Nisin caused a slow, gradual, time- and concentration-dependent decrease in internal ATP levels in M. bovis-BCG, but no ATP efflux was detected. In mycobacteria, nisin decreased both components of proton motive force (membrane potential, Delta Psi and Delta pH) in a time- and concentration-dependent manner. However, mycobacteria maintained their intracellular ATP levels during the initial time period of Delta Psi and Delta pH dissipation. These data suggest that the mechanism of nisin in mycobacteria is similar to that in food-borne pathogens.

  16. Evidence for the role of the Atlantic multidecadal oscillation and the ocean heat uptake in hiatus prediction

    Science.gov (United States)

    Pasini, Antonello; Triacca, Umberto; Attanasio, Alessandro

    2017-08-01

    The recent hiatus in global temperature at the surface has been analysed by several studies, mainly using global climate models. The common accepted picture is that since the late 1990s, the increase in anthropogenic radiative forcings has been counterbalanced by other factors, e.g., a decrease in natural forcings, augmented ocean heat storage and negative phases of ocean-atmosphere-coupled oscillation patterns. Here, simple vector autoregressive models are used for forecasting the temperature hiatus in the period 2001-2014. This gives new insight into the problem of understanding the ocean contribution (in terms of heat uptake and atmosphere-ocean-coupled oscillations) to the appearance of this recent hiatus. In particular, considering data about the ocean heat content until a depth of 700 m and the Atlantic multidecadal oscillation is necessary for correctly forecasting the hiatus, so catching both trend and interannual variability. Our models also show that the ocean heat uptake is substantially driven by the natural component of the total radiative forcing at a decadal time scale, confining the importance of the anthropogenic influences to a longer range warming of the ocean.

  17. Gravity-driven granular flow in a silo: Characterizing local forces and rearrangements

    Directory of Open Access Journals (Sweden)

    Thackray Emma

    2017-01-01

    Full Text Available While the gravity-driven flow of a granular material in a silo geometry can be modeled by the Beverloo equation, the mesoscale-level particle rearrangements and interactions that drive this flow are not wellunderstood. We have constructed a quasi-two-dimensional system of bidisperse, millimeter-scale disks with photoelastic properties that make force networks within the material visible. The system is contained in an acrylic box with an adjustable bottom opening. We can approach the clogging transition by adjusting this opening. By placing the system between cross-polarizers, we can obtain high-speed video of this system during flow, and extract intensity signals that can be used to identify and quantify localized, otherwise indeterminate forces. We can simultaneously track individual particle motions, which can be used to identify shear transformation zones in the system. In this paper, we present our results thus far.

  18. Personalizing Sample Databases with Facebook Information to Increase Intrinsic Motivation

    Science.gov (United States)

    Marzo, Asier; Ardaiz, Oscar; Sanz de Acedo, María Teresa; Sanz de Acedo, María Luisa

    2017-01-01

    Motivation is fundamental for students to achieve successful and complete learning. Motivation can be extrinsic, i.e., driven by external rewards, or intrinsic, i.e., driven by internal factors. Intrinsic motivation is the most effective and must be inspired by the task at hand. Here, a novel strategy is presented to increase intrinsic motivation…

  19. Adapted motivational interviewing to improve the uptake of treatment for glaucoma in Nigeria: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Abdull, Mohammed M; Gilbert, Clare; McCambridge, Jim; Evans, Jennifer

    2014-04-29

    Glaucoma is a chronic eye disease associated with irreversible visual loss. In Africa, glaucoma patients often present late, with very advanced disease. One-off procedures, such as laser or surgery, are recommended in Africa because of lack of or poor adherence to medical treatment. However, acceptance of surgery is usually extremely low. To prevent blindness, adherence to treatment needs to improve, using acceptable, replicable and cost-effective interventions. After reviewing the literature and interviewing patients in Bauchi (Nigeria) motivational interviewing (MI) was selected as the intervention for this trial, with adaptation for glaucoma (MIG). MI is designed to strengthen personal motivation for, and commitment to a specific goal by eliciting and exploring a person's reasons for change within an atmosphere of acceptance and compassion. The aim of this study is to assess whether MIG increases the uptake of laser or surgery amongst glaucoma patients where this is the recommended treatment. The hypothesis is that MIG increases the uptake of treatment. This will be the first trial of MI in Africa. This is a hospital based, single centre, randomized controlled trial of MIG plus an information sheet on glaucoma and its treatment (the latter being "standard care") compared with standard care alone for glaucoma patients where the treatment recommended is surgery or laser.Those eligible for the trial are adults aged 17 years and above who live within 200 km of Bauchi with advanced glaucoma where the examining ophthalmologist recommends surgery or laser. After obtaining written informed consent, participants will be randomly allocated to MIG plus standard care, or standard care alone. Motivational interviewing will be delivered in Hausa or English by one of two MIG trained personnel. One hundred and fifty participants will be recruited to each arm. The primary outcome is the proportion of participants undergoing laser or surgery within two months of the date given

  20. Current quantization and fractal hierarchy in a driven repulsive lattice gas.

    Science.gov (United States)

    Rotondo, Pietro; Sellerio, Alessandro Luigi; Glorioso, Pietro; Caracciolo, Sergio; Cosentino Lagomarsino, Marco; Gherardi, Marco

    2017-11-01

    Driven lattice gases are widely regarded as the paradigm of collective phenomena out of equilibrium. While such models are usually studied with nearest-neighbor interactions, many empirical driven systems are dominated by slowly decaying interactions such as dipole-dipole and Van der Waals forces. Motivated by this gap, we study the nonequilibrium stationary state of a driven lattice gas with slow-decayed repulsive interactions at zero temperature. By numerical and analytical calculations of the particle current as a function of the density and of the driving field, we identify (i) an abrupt breakdown transition between insulating and conducting states, (ii) current quantization into discrete phases where a finite current flows with infinite differential resistivity, and (iii) a fractal hierarchy of excitations, related to the Farey sequences of number theory. We argue that the origin of these effects is the competition between scales, which also causes the counterintuitive phenomenon that crystalline states can melt by increasing the density.

  1. Current quantization and fractal hierarchy in a driven repulsive lattice gas

    Science.gov (United States)

    Rotondo, Pietro; Sellerio, Alessandro Luigi; Glorioso, Pietro; Caracciolo, Sergio; Cosentino Lagomarsino, Marco; Gherardi, Marco

    2017-11-01

    Driven lattice gases are widely regarded as the paradigm of collective phenomena out of equilibrium. While such models are usually studied with nearest-neighbor interactions, many empirical driven systems are dominated by slowly decaying interactions such as dipole-dipole and Van der Waals forces. Motivated by this gap, we study the nonequilibrium stationary state of a driven lattice gas with slow-decayed repulsive interactions at zero temperature. By numerical and analytical calculations of the particle current as a function of the density and of the driving field, we identify (i) an abrupt breakdown transition between insulating and conducting states, (ii) current quantization into discrete phases where a finite current flows with infinite differential resistivity, and (iii) a fractal hierarchy of excitations, related to the Farey sequences of number theory. We argue that the origin of these effects is the competition between scales, which also causes the counterintuitive phenomenon that crystalline states can melt by increasing the density.

  2. Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

    Science.gov (United States)

    Abdallah, Muhammad E (Inventor); Platt, Jr., Robert J. (Inventor); Reiland, Matthew J (Inventor); Hargrave, Brian (Inventor); Diftler, Myron A (Inventor); Strawser, Philip A (Inventor); Ihrke, Chris A. (Inventor)

    2013-01-01

    A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions.

  3. Body-force-driven multiplicity and stability of combined free and forced convection in rotating curved ducts: Coriolis force

    Science.gov (United States)

    Yang, T.; Wang, L.

    A numerical study is made on the fully developed bifurcation structure and stability of forced convection in a rotating curved duct of square cross-section. Solution structure is determined as variation of a parameter that indicates the effect of rotation (Coriolis-force-driven multiplicity). Three solutions for the flows in a stationary curved duct obtained in the work of Yang and Wang [1] are used as initial solutions of continuation calculations to unfold the solution branches. Twenty-one solution branches are found comparing with five obtained by Selmi and Nandakumar [2]. Dynamic responses of the multiple solutions to finite random disturbances are examined by the direct transient computation. Results show that characteristics of physically realizable fully developed flows changes significantly with variation of effect of rotation. Fourteen sub-ranges are identified according to characteristics of physically realizable solutions. As rotation effect changes, possible physically realizable fully-developed flows can be stable steady 2-cell state, stable multi-cell state, temporal periodic oscillation between symmetric/asymmetric 2-cell/4-cell flows, temporal oscillation with intermittency, temporal chaotic oscillation and temporal oscillation with pseudo intermittency. Among these possible physically realizable fully developed flows, stable multi-cell state and stable steady 2-cell state exist as dual stable. And oscillation with pseudo intermittency is a new phenomenon. In addition to the temporal oscillation with intermittency, sudden shift from stationary stable solution to temporal chaotic oscillation is identified to be another way of onset of chaos.

  4. Taking the Test Taker's Perspective: Response Process and Test Motivation in Multidimensional Forced-Choice Versus Rating Scale Instruments.

    Science.gov (United States)

    Sass, Rachelle; Frick, Susanne; Reips, Ulf-Dietrich; Wetzel, Eunike

    2018-03-01

    The multidimensional forced-choice (MFC) format has been proposed as an alternative to the rating scale (RS) response format. However, it is unclear how changing the response format may affect the response process and test motivation of participants. In Study 1, we investigated the MFC response process using the think-aloud technique. In Study 2, we compared test motivation between the RS format and different versions of the MFC format (presenting 2, 3, 4, and 5 items simultaneously). The response process to MFC item blocks was similar to the RS response process but involved an additional step of weighing the items within a block against each other. The RS and MFC response format groups did not differ in their test motivation. Thus, from the test taker's perspective, the MFC format is somewhat more demanding to respond to, but this does not appear to decrease test motivation.

  5. Simulation-Driven Development and Optimization of a High-Performance Six-Dimensional Wrist Force/Torque Sensor

    Directory of Open Access Journals (Sweden)

    Qiaokang LIANG

    2010-05-01

    Full Text Available This paper describes the Simulation-Driven Development and Optimization (SDDO of a six-dimensional force/torque sensor with high performance. By the implementation of the SDDO, the developed sensor possesses high performance such as high sensitivity, linearity, stiffness and repeatability simultaneously, which is hard for tranditional force/torque sensor. Integrated approach provided by software ANSYS was used to streamline and speed up the process chain and thereby to deliver results significantly faster than traditional approaches. The result of calibration experiment possesses some impressive characters, therefore the developed fore/torque sensor can be usefully used in industry and the methods of design can also be used to develop industrial product.

  6. Neuroscientific Model of Motivational Process

    Science.gov (United States)

    Kim, Sung-il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area) in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision-making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area) play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area) and the dorsolateral prefrontal cortex (cognitive control area) are the main neural circuits related to regulation of motivation. These three sub processes interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment. PMID:23459598

  7. Neuroscientific model of motivational process.

    Science.gov (United States)

    Kim, Sung-Il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area) in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision-making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area) play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area) and the dorsolateral prefrontal cortex (cognitive control area) are the main neural circuits related to regulation of motivation. These three sub processes interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment.

  8. Neuroscientific Model of Motivational Process

    Directory of Open Access Journals (Sweden)

    Sung-Il eKim

    2013-03-01

    Full Text Available Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three subprocesses, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous subprocesses, namely reward-driven approach, value-based decision making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area and the dorsolateral prefrontal cortex (cognitive control area are the main neural circuits related to regulation of motivation. These three subprocesses interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment.

  9. Optimal arm posture control and tendon traction forces of a coupled tendon-driven manipulator

    International Nuclear Information System (INIS)

    Ma, Shugen

    1997-01-01

    In this study, the optimum arm posture of a coupled tendon-driven multijoint manipulator arm (or CT Arm) at maximum payload output was derived and the corresponding tendon traction forces were also analyzed, during management of a heavy payload by the manipulator in a gravity environment. The CT Arm is special tendon traction transmission mechanism in which a pair of tendons used to drive a joint is pulled from base actuators via pulleys mounted on the base-side joints. This mechanism enables optimal utilization of the coupled drive function of tendon traction forces and thus enables the lightweight manipulator to exhibit large payload capability. The properties of the CT Arm mechanism are elucidated by the proposed optimal posture control scheme. Computer simulation was also executed to verify the validity of the proposed control scheme. (author)

  10. Direction-dependent force-induced dissociation dynamics of an entropic-driven lock-and-key assembly.

    Science.gov (United States)

    Chen, Yen-Fu; Chen, Hsuan-Yi; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2017-09-01

    The unbinding dynamics of a nanosized sphere-and-cavity assembly under the pulling of constant force and constant loading rate is explored by dissipative particle dynamics simulations. The formation of this matched lock-and-key pair in a polymer solution is driven by the depletion attraction. The two-dimensional free energy landscape U(x,z) associated with this assembly is constructed. Our results indicate that the unbinding pathway along the orientation of the assembly is unfavorable due to the relatively high energy barrier compared to that along the tortuous minimum path whose energy barrier is not high. It is also found that the dissociation rate depends on the direction of the external force (θ) with respect to the assembly orientation. The presence of the force component perpendicular to the assembly orientation can reduce the bond lifetime significantly by driving the key particle to approach the minimum path. Moreover, the dissociation dynamics can be facilitated even by a pushing force compared to the spontaneous dissociation (without forces). To elucidate the effective pathway under pulling, the escaping position is analyzed and its mean direction with respect to the assembly orientation rises generally with increasing θ, revealing that the presence of the force component along the minimum pathway is helpful. The importance of the direction of the external pulling has been demonstrated in our simple system. Therefore, this effect should be considered in more complicated unbinding experiments.

  11. Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

    Science.gov (United States)

    Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

    2018-02-01

    Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

  12. Forcing, feedback and internal variability in global temperature trends.

    Science.gov (United States)

    Marotzke, Jochem; Forster, Piers M

    2015-01-29

    Most present-generation climate models simulate an increase in global-mean surface temperature (GMST) since 1998, whereas observations suggest a warming hiatus. It is unclear to what extent this mismatch is caused by incorrect model forcing, by incorrect model response to forcing or by random factors. Here we analyse simulations and observations of GMST from 1900 to 2012, and show that the distribution of simulated 15-year trends shows no systematic bias against the observations. Using a multiple regression approach that is physically motivated by surface energy balance, we isolate the impact of radiative forcing, climate feedback and ocean heat uptake on GMST--with the regression residual interpreted as internal variability--and assess all possible 15- and 62-year trends. The differences between simulated and observed trends are dominated by random internal variability over the shorter timescale and by variations in the radiative forcings used to drive models over the longer timescale. For either trend length, spread in simulated climate feedback leaves no traceable imprint on GMST trends or, consequently, on the difference between simulations and observations. The claim that climate models systematically overestimate the response to radiative forcing from increasing greenhouse gas concentrations therefore seems to be unfounded.

  13. Urological indications of Hg uptake in adults

    International Nuclear Information System (INIS)

    Jardin, A.

    1976-01-01

    The circumstances motivating the mercury bichloride uptake study of the kidney are specified: choice between excision and conservation surgery; estimation of the benefits of conservation surgical operations on the kidney or its excretion passage; estimation of the degree of compensative kidney hypertrophy in unilateral diseases or after nephrectomy. The urinary disorders for which mercury bichloride uptake is particularly suitable are also listed: acquires and congenital bilateral diseases of the excretion passage; hydronephrosis; complex lithiases [fr

  14. HPV vaccination prevalence, parental barriers and motivators to vaccinating children in Hawai'i.

    Science.gov (United States)

    Dela Cruz, May Rose Isnec; Braun, Kathryn L; Tsark, Jo Ann Umilani; Albright, Cheryl Lynn; Chen, John J

    2018-05-10

    To determine the prevalence and barriers to human papillomavirus (HPV) vaccine uptake among 11-18 year olds in the Hawai'i's four major ethnic groups-Native Hawaiians, Filipinos, Japanese, and Caucasians. A telephone survey assessed parents' knowledge of HPV and the HPV vaccine, status of their child's HPV vaccine uptake, variables operationalizing the Health Belief Model, and barriers and motivators to uptake. Across the groups, 799 parents completed the survey. About 35% of daughters and 19% of sons had received all three shots. Although ethnic differences in vaccine uptake were seen in bivariate analysis (with significantly lower uptake in Filipino youth), in multivariable logistic regression analysis, only Caucasian parents were significantly less likely to start their sons on the HPV vaccine series compared with Japanese parents (reference group). Having heard about the vaccine, believing in its effectiveness, and older age of the child were also associated with vaccine uptake. Motivators for HPV vaccination were physician's recommendation and wanting to protect one's child. The primary barrier to uptake was lack of knowledge about the vaccine. Findings reinforce the fact that a physician's recommendation and receipt of information about the vaccine are strong motivators for parents to vaccinate their children, regardless of ethnicity.

  15. Activating the Forces of Public Service Motivation

    DEFF Research Database (Denmark)

    Pedersen, Mogens Jin

    2015-01-01

    Employees with higher public service motivation (PSM) are likely to perform better in public service jobs. However, research on how practitioners may capitalize on this knowledge is sparse. This article expands the understanding of how to activate employee PSM, which is understood as a human...... resource that is present in the work environment. Using a randomized survey experiment with 528 law students, this article shows how low-intensity treatments may activate PSM and how the effect of PSM activation efforts compares with efforts to activate another, less self-determined type of motivation...

  16. Label-Free Detection of Bacillus anthracis Spore Uptake in Macrophage Cells Using Analytical Optical Force Measurements.

    Science.gov (United States)

    Hebert, Colin G; Hart, Sean; Leski, Tomasz A; Terray, Alex; Lu, Qin

    2017-10-03

    Understanding the interaction between macrophage cells and Bacillus anthracis spores is of significant importance with respect to both anthrax disease progression, spore detection for biodefense, as well as understanding cell clearance in general. While most detection systems rely on specific molecules, such as nucleic acids or proteins and fluorescent labels to identify the target(s) of interest, label-free methods probe changes in intrinsic properties, such as size, refractive index, and morphology, for correlation with a particular biological event. Optical chromatography is a label free technique that uses the balance between optical and fluidic drag forces within a microfluidic channel to determine the optical force on cells or particles. Here we show an increase in the optical force experienced by RAW264.7 macrophage cells upon the uptake of both microparticles and B. anthracis Sterne 34F2 spores. In the case of spores, the exposure was detected in as little as 1 h without the use of antibodies or fluorescent labels of any kind. An increase in the optical force was also seen in macrophage cells treated with cytochalasin D, both with and without a subsequent exposure to spores, indicating that a portion of the increase in the optical force arises independent of phagocytosis. These results demonstrate the capability of optical chromatography to detect subtle biological differences in a rapid and sensitive manner and suggest future potential in a range of applications, including the detection of biological threat agents for biodefense and pathogens for the prevention of sepsis and other diseases.

  17. Proton pump-driven cutaneous chloride uptake in anuran amphibia

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Willumsen, Niels J.; Amstrup, Jan

    2003-01-01

    Krogh introduced the concept of active ion uptake across surface epithelia of freshwater animals, and proved independent transports of Na(+) and Cl(-) in anuran skin and fish gill. He suggested that the fluxes of Na(+) and Cl(-) involve exchanges with ions of similar charge. In the so-called Krog...

  18. Torque control of underactuated tendon-driven fingers

    Directory of Open Access Journals (Sweden)

    M. E. Abdallah

    2011-02-01

    Full Text Available Given an underactuated tendon-driven finger, the finger posture is underdetermined and can move freely ("flop" in a region of slack tendons. This work shows that such an underactuated finger can be operated in tendon force control (rather than position control with effective performance. The force control eliminates the indeterminate slack while commanding a parameterized space of desired torques. The torque will either push the finger to the joint limits or wrap around an external object with variable torque – behavior that is sufficient for primarily gripping fingers. In addition, introducing asymmetric joint radii to the design allows the finger to command an expanded range of joint torques and to scan an expanded set of external surfaces. This study is motivated by the design and control of the secondary fingers of the NASA-GM R2 humanoid hand.

    This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

  19. Beyond Tree Throw: Wind, Water, Rock and the Mechanics of Tree-Driven Bedrock Physical Weathering

    Science.gov (United States)

    Marshall, J. A.; Anderson, R. S.; Dawson, T. E.; Dietrich, W. E.; Minear, J. T.

    2017-12-01

    Tree throw is often invoked as the dominant process in converting bedrock to soil and thus helping to build the Critical Zone (CZ). In addition, observations of tree roots lifting sidewalk slabs, occupying cracks, and prying slabs of rock from cliff faces have led to a general belief in the power of plant growth forces. These common observations have led to conceptual models with trees at the center of the soil genesis process. This is despite the observation that tree throw is rare in many forested settings, and a dearth of field measurements that quantify the magnitude of growth forces. While few trees blow down, every tree grows roots, inserting many tens of percent of its mass below ground. Yet we lack data quantifying the role of trees in both damaging bedrock and detaching it (and thus producing soil). By combing force measurements at the tree-bedrock interface with precipitation, solar radiation, wind speed, and wind-driven tree sway data we quantified the magnitude and frequency of tree-driven soil-production mechanisms from two contrasting climatic and lithologic regimes (Boulder and Eel Creek CZ Observatories). Preliminary data suggests that in settings with relatively thin soils, trees can damage and detach rock due to diurnal fluctuations, wind response and rainfall events. Surprisingly, our data suggests that forces from roots and trunks growing against bedrock are insufficient to pry rock apart or damage bedrock although much more work is needed in this area. The frequency, magnitude and style of wind-driven tree forces at the bedrock interface varies considerably from one to another species. This suggests that tree properties such as mass, elasticity, stiffness and branch structure determine whether trees respond to gusts big or small, move at the same frequency as large wind gusts, or are able to self-dampen near-ground sway response to extended wind forces. Our measurements of precipitation-driven and daily fluctuations in root pressures exerted on

  20. Life-space foam: A medium for motivational and cognitive dynamics

    Science.gov (United States)

    Ivancevic, Vladimir; Aidman, Eugene

    2007-08-01

    General stochastic dynamics, developed in a framework of Feynman path integrals, have been applied to Lewinian field-theoretic psychodynamics [K. Lewin, Field Theory in Social Science, University of Chicago Press, Chicago, 1951; K. Lewin, Resolving Social Conflicts, and, Field Theory in Social Science, American Psychological Association, Washington, 1997; M. Gold, A Kurt Lewin Reader, the Complete Social Scientist, American Psychological Association, Washington, 1999], resulting in the development of a new concept of life-space foam (LSF) as a natural medium for motivational and cognitive psychodynamics. According to LSF formalisms, the classic Lewinian life space can be macroscopically represented as a smooth manifold with steady force fields and behavioral paths, while at the microscopic level it is more realistically represented as a collection of wildly fluctuating force fields, (loco)motion paths and local geometries (and topologies with holes). A set of least-action principles is used to model the smoothness of global, macro-level LSF paths, fields and geometry. To model the corresponding local, micro-level LSF structures, an adaptive path integral is used, defining a multi-phase and multi-path (multi-field and multi-geometry) transition process from intention to goal-driven action. Application examples of this new approach include (but are not limited to) information processing, motivational fatigue, learning, memory and decision making.

  1. Self-Driven Service Learning: Community-Student-Faculty Collaboratives Outside of the Classroom

    Directory of Open Access Journals (Sweden)

    Veronica A. Segarra

    2015-08-01

    Full Text Available Service learning is a community engagement pedagogy often used in the context of the undergraduate classroom to synergize course-learning objectives with community needs.  We find that an effective way to catalyze student engagement in service learning is for student participation to occur outside the context of a graded course, driven by students’ own interests and initiative.  In this paper, we describe the creation and implementation of a self-driven service learning program and discuss its benefits from the community, student, and faculty points of view.  This experience allows students to explore careers in the sciences as well as identify skill strengths and weaknesses in an environment where mentoring is available but where student initiative and self-motivation are the driving forces behind the project’s success.  Self-driven service learning introduces young scientists to the idea that their careers serve a larger community that benefits not only from their discoveries but also from effective communication about how these discoveries are relevant to everyday life.

  2. IDENTIFYING MOTIVATION FACTOR INVOLVEMENT OF SARAWAK MALAY WOMEN ENTREPRENEUR

    Directory of Open Access Journals (Sweden)

    Masyantie Mohamad

    2016-03-01

    Full Text Available Sarawak multilayered cake among Sarawak product signature famous among the local as well as international tourist visiting Sarawak. In fact, Sarawak Malay women entrepreneurs have become very necessary players in the entrepreneurial field specifically in this cottage industries from the early introduction of this business, they have facing various problem in this businesses. Thus, this research aims to build an understanding of motivational factor that encourage Sarawak Malay women entrepreneurial experiences especially in multilayered cake businesses. Using qualitative methods, this research aims to identify the entrepreneurial motivations factors; with regards to start-up motivation by Sarawak Malay women. The finding shows that the motivations that influence Malay women within Kuching, Sarawak areas to start and grow their business are involve self-driven and context driven that motivate them involve in multilayered cakes businesses.

  3. Clustering Teachers' Motivations for Teaching

    Science.gov (United States)

    Visser-Wijnveen, Gerda J.; Stes, Ann; Van Petegem, Peter

    2014-01-01

    The motivation to teach is a powerful, yet neglected, force in teaching at institutes of higher education. A better understanding of academics' motivations for teaching is necessary. The aim of this mixed-method study was to identify groups with distinctively different motivations for teaching. Six clusters were identified: expertise, duty,…

  4. Motivation and Resolve of U.S. Air Force Pilot Candidates

    Science.gov (United States)

    2017-06-15

    demonstrated character and emotional composure (stability), and a consistent desire and proven resolve to become, and remain, a pilot ( motivation ). MFS-N... motivation used at MFS-N. The goals of this research are to better understand what motivates pilot candidates to pursue aviation careers and to establish...baseline motivation and grit scores. These scores can then be utilized, in conjunction with other MFS-N testing information, to understand pre-morbid

  5. Transport of Amino Acids in Lactobacillus casei by Proton-Motive-Force-Dependent and Non-Proton-Motive-Force-Dependent Mechanisms

    NARCIS (Netherlands)

    Strobel, Herbert J.; Russell, James B.; Driessen, Arnold J.M.; Konings, Wilhelmus

    Lactobacilus casei 393 cells which were energized with glucose (pH 6.0) took up glutamine, asparagine, glutamate, aspartate, leucine, and phenylalanine. Little or no uptake of several essential amino acids (valine, isoleucine, arginine, cysteine, tyrosine, and tryptophan) was observed. Inhibition

  6. How winning changes motivation in multiphase competitions.

    Science.gov (United States)

    Huang, Szu-Chi; Etkin, Jordan; Jin, Liyin

    2017-06-01

    What drives motivation in multiphase competitions? Adopting a dynamic approach, this research examines how temporary standing-being ahead of (vs. behind) one's opponent-in a multiphase competition shapes subsequent motivation. Six competitions conducted in the lab and in the field demonstrate that the impact of being ahead on contestants' motivation depends on when (i.e., in which phase of the competition) contestants learn they are in the lead. In the early phase, contestants are concerned about whether they can win; being ahead increases motivation by making winning seem more attainable. In the later phase, however, contestants are instead driven by how much additional effort they believe they need to invest; being ahead decreases motivation by reducing contestants' estimate of the remaining effort needed to win. Temporary standing thus has divergent effects on motivation in multiphase competitions, driven by a shift in contestants' main concern from the early to the later phase and thus the meaning they derive from being ahead of their opponent. By leveraging insights gained from approaching individuals' self-regulation as a dynamic process, this research advances understanding of how motivation evolves in a unique interdependent self-regulatory context. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Tropically driven and externally forced patterns of Antarctic sea ice change: reconciling observed and modeled trends

    Science.gov (United States)

    Schneider, David P.; Deser, Clara

    2017-09-01

    Recent work suggests that natural variability has played a significant role in the increase of Antarctic sea ice extent during 1979-2013. The ice extent has responded strongly to atmospheric circulation changes, including a deepened Amundsen Sea Low (ASL), which in part has been driven by tropical variability. Nonetheless, this increase has occurred in the context of externally forced climate change, and it has been difficult to reconcile observed and modeled Antarctic sea ice trends. To understand observed-model disparities, this work defines the internally driven and radiatively forced patterns of Antarctic sea ice change and exposes potential model biases using results from two sets of historical experiments of a coupled climate model compared with observations. One ensemble is constrained only by external factors such as greenhouse gases and stratospheric ozone, while the other explicitly accounts for the influence of tropical variability by specifying observed SST anomalies in the eastern tropical Pacific. The latter experiment reproduces the deepening of the ASL, which drives an increase in regional ice extent due to enhanced ice motion and sea surface cooling. However, the overall sea ice trend in every ensemble member of both experiments is characterized by ice loss and is dominated by the forced pattern, as given by the ensemble-mean of the first experiment. This pervasive ice loss is associated with a strong warming of the ocean mixed layer, suggesting that the ocean model does not locally store or export anomalous heat efficiently enough to maintain a surface environment conducive to sea ice expansion. The pervasive upper-ocean warming, not seen in observations, likely reflects ocean mean-state biases.

  8. Tropically driven and externally forced patterns of Antarctic sea ice change: reconciling observed and modeled trends

    Science.gov (United States)

    Schneider, David P.; Deser, Clara

    2018-06-01

    Recent work suggests that natural variability has played a significant role in the increase of Antarctic sea ice extent during 1979-2013. The ice extent has responded strongly to atmospheric circulation changes, including a deepened Amundsen Sea Low (ASL), which in part has been driven by tropical variability. Nonetheless, this increase has occurred in the context of externally forced climate change, and it has been difficult to reconcile observed and modeled Antarctic sea ice trends. To understand observed-model disparities, this work defines the internally driven and radiatively forced patterns of Antarctic sea ice change and exposes potential model biases using results from two sets of historical experiments of a coupled climate model compared with observations. One ensemble is constrained only by external factors such as greenhouse gases and stratospheric ozone, while the other explicitly accounts for the influence of tropical variability by specifying observed SST anomalies in the eastern tropical Pacific. The latter experiment reproduces the deepening of the ASL, which drives an increase in regional ice extent due to enhanced ice motion and sea surface cooling. However, the overall sea ice trend in every ensemble member of both experiments is characterized by ice loss and is dominated by the forced pattern, as given by the ensemble-mean of the first experiment. This pervasive ice loss is associated with a strong warming of the ocean mixed layer, suggesting that the ocean model does not locally store or export anomalous heat efficiently enough to maintain a surface environment conducive to sea ice expansion. The pervasive upper-ocean warming, not seen in observations, likely reflects ocean mean-state biases.

  9. Electromagnetic Properties Analysis on Hybrid-driven System of Electromagnetic Motor

    Science.gov (United States)

    Zhao, Jingbo; Han, Bingyuan; Bei, Shaoyi

    2018-01-01

    The hybrid-driven system made of permanent-and electromagnets applied in the electromagnetic motor was analyzed, equivalent magnetic circuit was used to establish the mathematical models of hybrid-driven system, based on the models of hybrid-driven system, the air gap flux, air-gap magnetic flux density, electromagnetic force was proposed. Taking the air-gap magnetic flux density and electromagnetic force as main research object, the hybrid-driven system was researched. Electromagnetic properties of hybrid-driven system with different working current modes is studied preliminary. The results shown that analysis based on hybrid-driven system can improve the air-gap magnetic flux density and electromagnetic force more effectively and can also guarantee the output stability, the effectiveness and feasibility of the hybrid-driven system are verified, which proved theoretical basis for the design of hybrid-driven system.

  10. Participation in Biodiversity Conservation: Motivations and Barriers of Australian Landholders

    Science.gov (United States)

    Moon, Katie; Cocklin, Chris

    2011-01-01

    Biodiversity conservation programs that appeal to landholders' motivations and minimise their barriers to participation may result in both increased uptake rates and improved ecological outcomes. To understand their motivations and barriers to conserve biodiversity, qualitative interviews were conducted with 45 landholders who had participated in…

  11. The role of theory-driven graphic warning labels in motivation to quit: a qualitative study on perceptions from low-income, urban smokers.

    Science.gov (United States)

    Mead, Erin L; Cohen, Joanna E; Kennedy, Caitlin E; Gallo, Joseph; Latkin, Carl A

    2015-02-07

    Use of communication theories in the development of pictorial health warning labels (graphic warning labels) for cigarette packaging might enhance labels' impact on motivation to quit, but research has been limited, particularly among low socioeconomic status (SES) populations in the U.S. This qualitative study explored perceptions of theory-based graphic warning labels and their role in motivation to quit among low-income smokers. A cross-sectional qualitative study was conducted with 25 low-income adult smokers in Baltimore, Maryland, who were purposively sampled from a community-based source population. Semi-structured, in-depth interviews were conducted from January to February 2014. Participants were asked about the motivational impact of 12 labels falling into four content categories: negative depictions of the health effects of smoking to smokers and others, and positive depictions of the benefits of quitting to smokers and others. Data were coded using a combined inductive/deductive approach and analyzed thematically through framework analysis. Labels depicting negative health effects to smokers were identified as most motivational, followed by labels depicting negative health effects to others. Reasons included perceived severity of and susceptibility to the effects, negative emotional reactions (such as fear), and concern for children. Labels about the benefits of quitting were described as motivational because of their hopefulness, characters as role models, and desire to improve family health. Reasons why labels were described as not motivational included lack of impact on perceived severity/susceptibility, low credibility, and fatalistic attitudes regarding the inevitability of disease. Labels designed to increase risk perceptions from smoking might be significant sources of motivation for low SES smokers. Findings suggest innovative theory-driven approaches for the design of labels, such as using former smokers as role models, contrasting healthy and

  12. An Exploration on Motivation of Non-English Majors in Polytechnics

    Institute of Scientific and Technical Information of China (English)

    赵庆伟

    2016-01-01

    This study, undertaken 100 students majoring in electronics in a polytechnic in TianJin, examines the characteristics of learning motivations in students: intrinsic and extrinsic motivation. Analysis of data acquired from a questionnaire suggests that the majority of polytechnic students are driven by extrinsic motivation.

  13. Functional Food Market Development in Serbia: Motivations and Barriers

    Directory of Open Access Journals (Sweden)

    Žaklina Stojanović

    2013-11-01

    Full Text Available The aim of this paper is to present main findings obtained from the empirical analysis of the functional food market in Serbia. The analysis is based on the in-depth interviews with relevant processors and retailers present on the market. The following set of topics are considered: (1 motivations (driving forces and barriers to offer products with nutrition and health (N&H claim and (2 perception of consumer demand toward N&H claimed products. Differences between Serbia and other Western Balkan Countries (WBC are explored by using nonparametric techniques based on the independent samples. Results support overall conclusion that this market segment in Serbia is underdeveloped and rather producer than consumer driven compared to more developed WBC markets.

  14. Motivational Goal Bracketing

    DEFF Research Database (Denmark)

    Nafziger, Julia; Koch, Alexander

    It is a puzzle why people often evaluate consequences of choices separately (narrow bracketing) rather than jointly (broad bracketing). We study the hypothesis that a present-biased individual, who faces two tasks, may bracket his goals narrowly for motivational reasons. Goals motivate because th...... of the tasks. Narrow goals have a stronger motivational force and thus can be optimal. In particular, if one task outcome becomes known before working on the second task, narrow bracketing is always optimal.......It is a puzzle why people often evaluate consequences of choices separately (narrow bracketing) rather than jointly (broad bracketing). We study the hypothesis that a present-biased individual, who faces two tasks, may bracket his goals narrowly for motivational reasons. Goals motivate because...

  15. Hunger-Driven Motivational State Competition.

    Science.gov (United States)

    Burnett, C Joseph; Li, Chia; Webber, Emily; Tsaousidou, Eva; Xue, Stephen Y; Brüning, Jens C; Krashes, Michael J

    2016-10-05

    Behavioral choice is ubiquitous in the animal kingdom and is central to goal-oriented behavior. Hypothalamic Agouti-related peptide (AgRP) neurons are critical regulators of appetite. Hungry animals, bombarded by multiple sensory stimuli, are known to modify their behavior during times of caloric need, rapidly adapting to a consistently changing environment. Utilizing ARC AgRP neurons as an entry point, we analyzed the hierarchical position of hunger related to rival drive states. Employing a battery of behavioral assays, we found that hunger significantly increases its capacity to suppress competing motivational systems, such as thirst, anxiety-related behavior, innate fear, and social interactions, often only when food is accessible. Furthermore, real-time monitoring of ARC AgRP activity revealed time-locked responses to conspecific investigation in addition to food presentation, further establishing that, even at the level of ARC AgRP neurons, choices are remarkably flexible computations, integrating internal state, external factors, and anticipated yield. VIDEO ABSTRACT. Published by Elsevier Inc.

  16. A one-dimensional model of the semiannual oscillation driven by convectively forced gravity waves

    Science.gov (United States)

    Sassi, Fabrizio; Garcia, Rolando R.

    1994-01-01

    A one-dimensional model that solves the time-dependent equations for the zonal mean wind and a wave of specified zonal wavenumber has been used to illustrate the ability of gravity waves forced by time-dependent tropospheric heating to produce a semiannual oscillation (SAO) in the middle atmosphere. When the heating has a strong diurnal cycle, as observed over tropical landmasses, gravity waves with zonal wavelengths of a few thousand kilometers and phase velocities in the range +/- 40-50 m/sec are excited efficiently by the maximum vertical projection criterion (vertical wavelength approximately equals 2 x forcing depth). Calculations show that these waves can account for large zonal mean wind accelerations in the middle atmosphere, resulting in realistic stratopause and mesopause oscillations. Calculations of the temporal evolution of a quasi-conserved tracer indicate strong down-welling in the upper stratosphere near the equinoxes, which is associated with the descent of the SAO westerlies. In the upper mesosphere, there is a semiannual oscillation in tracer mixing ratio driven by seasonal variability in eddy mixing, which increases at the solstices and decreases at the equinoxes.

  17. Separating the Effects of Tropical Atlantic and Pacific SST-driven Climate Variability on Amazon Carbon Exchange

    Science.gov (United States)

    Liptak, J.; Keppel-Aleks, G.

    2016-12-01

    Amazon forests store an estimated 25% percent of global terrestrial carbon per year1, 2, but the responses of Amazon carbon uptake to climate change is highly uncertain. One source of this uncertainty is tropical sea surface temperature variability driven by teleconnections. El Nino-Southern Oscillation (ENSO) is a key driver of year-to-year Amazon carbon exchange, with associated temperature and precipitation changes favoring net carbon storage in La Nina years, and net carbon release during El Nino years3. To determine how Amazon climate and terrestrial carbon fluxes react to ENSO alone and in concert with other SST-driven teleconnections such as the Atlantic Multidecadal Oscillation (AMO), we force the atmosphere (CAM5) and land (CLM4) components of the CESM(BGC) with prescribed monthly SSTs over the period 1950—2014 in a Historical control simulation. We then run an experiment (PAC) with time-varying SSTs applied only to the tropical equatorial Pacific Ocean, and repeating SST seasonal cycle climatologies elsewhere. Limiting SST variability to the equatorial Pacific indicates that other processes enhance ENSO-driven Amazon climate anomalies. Compared to the Historical control simulation, warming, drying and terrestrial carbon loss over the Amazon during El Nino periods are lower in the PAC simulation, especially prior to 1990 during the cool phase of the AMO. Cooling, moistening, and net carbon uptake during La Nina periods are also reduced in the PAC simulation, but differences are greater after 1990 during the warm phase of the AMO. By quantifying the relationships among climate drivers and carbon fluxes in the Historical and PAC simulations, we both assess the sensitivity of these relationships to the magnitude of ENSO forcing and quantify how other teleconnections affect ENSO-driven Amazon climate feedbacks. We expect that these results will help us improve hypotheses for how Atlantic and Pacific climate trends will affect future Amazon carbon carbon

  18. How realistic are air quality hindcasts driven by forcings from climate model simulations?

    Science.gov (United States)

    Lacressonnière, G.; Peuch, V.-H.; Arteta, J.; Josse, B.; Joly, M.; Marécal, V.; Saint Martin, D.; Déqué, M.; Watson, L.

    2012-12-01

    Predicting how European air quality could evolve over the next decades in the context of changing climate requires the use of climate models to produce results that can be averaged in a climatologically and statistically sound manner. This is a very different approach from the one that is generally used for air quality hindcasts for the present period; analysed meteorological fields are used to represent specifically each date and hour. Differences arise both from the fact that a climate model run results in a pure model output, with no influence from observations (which are useful to correct for a range of errors), and that in a "climate" set-up, simulations on a given day, month or even season cannot be related to any specific period of time (but can just be interpreted in a climatological sense). Hence, although an air quality model can be thoroughly validated in a "realistic" set-up using analysed meteorological fields, the question remains of how far its outputs can be interpreted in a "climate" set-up. For this purpose, we focus on Europe and on the current decade using three 5-yr simulations performed with the multiscale chemistry-transport model MOCAGE and use meteorological forcings either from operational meteorological analyses or from climate simulations. We investigate how statistical skill indicators compare in the different simulations, discriminating also the effects of meteorology on atmospheric fields (winds, temperature, humidity, pressure, etc.) and on the dependent emissions and deposition processes (volatile organic compound emissions, deposition velocities, etc.). Our results show in particular how differing boundary layer heights and deposition velocities affect horizontal and vertical distributions of species. When the model is driven by operational analyses, the simulation accurately reproduces the observed values of O3, NOx, SO2 and, with some bias that can be explained by the set-up, PM10. We study how the simulations driven by climate

  19. Nucleus Accumbens Microcircuit Underlying D2-MSN-Driven Increase in Motivation.

    Science.gov (United States)

    Soares-Cunha, Carina; Coimbra, Bárbara; Domingues, Ana Verónica; Vasconcelos, Nivaldo; Sousa, Nuno; Rodrigues, Ana João

    2018-01-01

    The nucleus accumbens (NAc) plays a central role in reinforcement and motivation. Around 95% of the NAc neurons are medium spiny neurons (MSNs), divided into those expressing dopamine receptor D1 (D1R) or dopamine receptor D2 (D2R). Optogenetic activation of D2-MSNs increased motivation, whereas inhibition of these neurons produced the opposite effect. Yet, it is still unclear how activation of D2-MSNs affects other local neurons/interneurons or input terminals and how this contributes for motivation enhancement. To answer this question, in this work we combined optogenetic modulation of D2-MSNs with in loco pharmacological delivery of specific neurotransmitter antagonists in rats. First, we showed that optogenetic activation of D2-MSNs increases motivation in a progressive ratio (PR) task. We demonstrated that this behavioral effect relies on cholinergic-dependent modulation of dopaminergic signalling of ventral tegmental area (VTA) terminals, which requires D1R and D2R signalling in the NAc. D2-MSN optogenetic activation decreased ventral pallidum (VP) activity, reducing the inhibitory tone to VTA, leading to increased dopaminergic activity. Importantly, optogenetic activation of D2-MSN terminals in the VP was sufficient to recapitulate the motivation enhancement. In summary, our data suggests that optogenetic stimulation of NAc D2-MSNs indirectly modulates VTA dopaminergic activity, contributing for increased motivation. Moreover, both types of dopamine receptors signalling in the NAc are required in order to produce the positive behavioral effects.

  20. The Measurement of Motivation with Science Students

    Science.gov (United States)

    Mubeen, Sarwat; Reid, Norman

    2014-01-01

    Motivation is an inner force that activates and provides direction to our thought, feelings and actions. Two main characteristics of motivation are goal directed behavior and persistence. Motivated people persistently work for the goal until it is achieved. This paper explores the nature of motivation in the context of learning and seeks to relate…

  1. Attendance motivations and visitor segments within a university agricultural festival

    Science.gov (United States)

    Carla Barbieri; Yasuharu Katsube; Christine Tew

    2010-01-01

    Festivals attract a variety of visitors driven by a complex set of motivations. The objective of this study was to identify and classify motivations for attending the South Farm Showcase (SFS), a university-based agricultural festival in Missouri. The study further developed a motivation-based segmentation of festival visitors and examined their distinct...

  2. The Adaptation of Academic Motivation Scale to Turkish

    Science.gov (United States)

    Karaguven, M. Hulya Unal

    2012-01-01

    The current study evaluated the psychometric evidence of Turkish form of the Academic Motivation Scale. The scale was based on the tenets of self-determination theory. It was designed to assess an individual's academic motivation if intrinsically or extrinsically driven with 28 questions. University form of the scale was translated into Turkish…

  3. Orientation of Steel Fibers in Magnetically Driven Concrete and Mortar.

    Science.gov (United States)

    Xue, Wen; Chen, Ju; Xie, Fang; Feng, Bing

    2018-01-22

    The orientation of steel fibers in magnetically driven concrete and magnetically driven mortar was experimentally studied in this paper using a magnetic method. In the magnetically driven concrete, a steel slag was used to replace the coarse aggregate. In the magnetically driven mortar, steel slag and iron sand were used to replace the fine aggregate. A device was established to provide the magnetic force. The magnetic force was used to rotate the steel fibers. In addition, the magnetic force was also used to vibrate the concrete and mortar. The effect of magnetic force on the orientation of steel fibers was examined by comparing the direction of fibers before and after vibration. The effect of magnetically driven concrete and mortar on the orientation of steel fibers was also examined by comparing specimens to normal concrete and mortar. It is shown that the fibers could rotate about 90° in magnetically driven concrete. It is also shown that the number of fibers rotated in magnetically driven mortar was much more than in mortar vibrated using a shaking table. A splitting test was performed on concrete specimens to investigate the effect of fiber orientation. In addition, a flexural test was also performed on mortar test specimens. It is shown that the orientation of the steel fibers in magnetically driven concrete and mortar affects the strength of the concrete and mortar specimens.

  4. Video-based Analysis of Motivation and Interaction in Science Classrooms

    DEFF Research Database (Denmark)

    Andersen, Hanne Moeller; Nielsen, Birgitte Lund

    2013-01-01

    in groups. Subsequently, the framework was used for an analysis of students’ motivation in the whole class situation. A cross-case analysis was carried out illustrating characteristics of students’ motivation dependent on the context. This research showed that students’ motivation to learn science...... is stimulated by a range of different factors, with autonomy, relatedness and belonging apparently being the main sources of motivation. The teacher’s combined use of questions, uptake and high level evaluation was very important for students’ learning processes and motivation, especially students’ self......An analytical framework for examining students’ motivation was developed and used for analyses of video excerpts from science classrooms. The framework was developed in an iterative process involving theories on motivation and video excerpts from a ‘motivational event’ where students worked...

  5. Engaging energy saving through motivation-specific social comparison

    OpenAIRE

    Petkov, Petromil;Köbler, Felix;Foth, Marcus;Medland, Richard C.;Krcmar, Helmut

    2014-01-01

    Comparison is widely used in research projects and commercial products whose goal is to motivate energy saving at home. This research builds on fundamental theories from social psychology in an attempt to shed light on how to motivate consumers to conserve energy by providing relevant people for social comparison depending on consumer?s motivation to compare. To support the research process, the mobile application EnergyWiz was developed through a theory-driven design approach. Along with oth...

  6. Function of TiO2 Lattice Defects toward Photocatalytic Processes: View of Electronic Driven Force

    Directory of Open Access Journals (Sweden)

    Huanan Cui

    2013-01-01

    Full Text Available Oxygen vacancies and Ti-related defects (OTDs are the main lattice defects of TiO2, which have great influence on its photocatalytic activity. To understand the relationship between the defects and photocatalytic activities, detailed discussions based on the electronic driven force provided by these defects are carried out during the three commonly accepted processes in photocatalytic reactions. It is found that these defects inevitably (i influence the energy structure of the pristine TiO2 as the isolate acceptor/donor level or hybrid with the original orbital, (ii provide a disordered short-range force that confuses the charge carriers transferring to surface active sites, (iii act not only as the surface active sites for trapping the charge carriers but also as the main chemisorption sites for O2, H2O, and organic species. These effects of the defects make them one of the key factors that determine the efficiency of heterogeneous photocatalysis. Clarifying the role of the defects will further facilitate the exploration and the construction of high-performance photocatalysts for practical applications.

  7. Extrinsic vs Intrinsic Motivations for Tax Compliance. Evidence from a Randomized Field Experiment in Germany

    OpenAIRE

    Dwenger, Nadja; Kleven, Henrik; Rasul, Imran; Rincke, Johannes

    2014-01-01

    Is tax compliance driven only by extrinsic motivations such as deterrence and tax policy or is there also a role for intrinsic motivations such as morals, norms and psychology? Agents may comply based on moral sentiments, social norms, guilt and shame (Andreoni et al. 1998), all of which are non-deterrence driven reasons for compliance. The importance of such intrinsically motivated compliance is hard to study empirically and therefore the least understood. This study uses a unique setting fo...

  8. Characteristics of sugar uptake by immature maize embryos

    International Nuclear Information System (INIS)

    Griffith, S.M.; Jones, R.J.; Brenner, M.L.

    1986-01-01

    Characteristics of sugar uptake by immature maize embryos were determined in vitro utilizing a 14 C-sugar solution incubation method. Hexose uptake rates were greater than those for sucrose, however, all showed biphasic kinetics. Glucose and fructose saturable components were evidence at <50 mM and sucrose at <5 mM. Chemical inhibitors (CCCP, DNP, NaCN, and PCMBS) and low temperature reduced sugar uptake. Sucrose influx was pH dependent while glucose was not. Embryos maintained a high sucrose to hexose ratio throughout development. At 25 days after pollination sucrose levels exceeded 200 mM while hexose levels remained below 5 mM. Glucose was rapidly converted to sucrose upon transport into the embryo. These circumstantial data indicate that sugar uptake by immature maize embryos is metabolically dependent and carrier mediated. Furthermore, sucrose transport appears to occur against its concentration gradient involving a H+/sucrose cotransport mechanism, while glucose influx is driven by its concentration gradient and subsequent metabolism

  9. Current-driven turbulence in plasmas

    International Nuclear Information System (INIS)

    Kluiver, H. de.

    1977-10-01

    Research on plasma heating in linear and toroidal systems using current-driven turbulence is reviewed. The motivation for this research is presented. Relations between parameters describing the turbulent plasma state and macroscopic observables are given. Several linear and toroidal devices used in current-driven turbulence studies are described, followed by a discussion of special diagnostic methods used. Experimental results on the measurement of electron and ion heating, anomalous plasma conductivity and associated turbulent fluctuation spectra are reviewed. Theories on current-driven turbulence are discussed and compared with experiments. It is demonstrated from the experimental results that current-driven turbulence occurs not only for extreme values of the electric field but also for an experimentally much more accessible and wide range of parameters. This forms a basis for a discussion on possible future applications in fusion-oriented plasma research

  10. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    International Nuclear Information System (INIS)

    Lu, Yi-Ching; Chang, Fan-Yu; Tu, Shu-Ju; Chen, Jyh-Ping; Ma, Yunn-Hwa

    2017-01-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNP cell ) appeared to be magnetic field- and concentration-dependent. In H-field, MNP cell reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNP cell , suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNP cell in the L-field may reach as high as 80% of that in H-field during 1–6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNP cell analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo. - Graphical abstract: Averaged MNP uptake by glioma cells in the low and non-uniformed magnetic field reached as high as 80% of that in uniformed magnetic field, which is probably due to both heterogeneous distributions of MNPs in the non-uniformed magnetic field and high capacity of the MNP uptake by these cells. - Highlights: • Enhanced sedimentation

  11. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi-Ching; Chang, Fan-Yu [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Tu, Shu-Ju [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Chen, Jyh-Ping [Department of Chemical and Materials Engineering, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Ma, Yunn-Hwa, E-mail: yhma@mail.cgu.edu.tw [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Department of Neurology, Chang Gung Memorial Hospital, Guishan, Taoyuan City 33305, Taiwan, ROC (China)

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNP{sub cell}) appeared to be magnetic field- and concentration-dependent. In H-field, MNP{sub cell} reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNP{sub cell}, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNP{sub cell} in the L-field may reach as high as 80% of that in H-field during 1–6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNP{sub cell} analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo. - Graphical abstract: Averaged MNP uptake by glioma cells in the low and non-uniformed magnetic field reached as high as 80% of that in uniformed magnetic field, which is probably due to both heterogeneous distributions of MNPs in the non-uniformed magnetic field and high capacity of the MNP uptake by these cells. - Highlights:

  12. Interactions Between Structure and Processing that Control Moisture Uptake in High-Performance Polycyanurates (Briefing Charts)

    Science.gov (United States)

    2015-03-24

    Motivation • SOTA Theories of Moisture Uptake in Thermosetting Networks • New Tools and New Discoveries • Unresolved Issues and Ways to Address Them...Temperature Thermosetting Polymers: Cyanate Esters • Glass transition temperatures at full cure of 200 – 400°C • Uncured resins exist as low-melting solids...Summary: Basic Studies of Moisture Uptake in Cyanate Ester Networks • Many aspects of moisture uptake (and its minimization) in thermosetting polymer

  13. Motivational and Ideological Underpinnings of Welfare Preferences in Eastern and Western Europe

    Science.gov (United States)

    Hadarics, Márton

    2016-01-01

    In our study we investigated the motivational and ideological correlates of the approval of welfare services in postsocialist Central Eastern and Western Europe. In the centre of our inquiry stood how the motivations of selflessness and conventionality, along with distributional justice principles, are related to our welfare preferences beyond our rational self-interest, furthermore, how these associations depend on social-cultural circumstances. We have found that the motivational background of egalitarian economic and welfare attitudes are substantially different in the two regions. While beside of the rationalisation of self-interest, it seems to be related to selflessness-driven solidarity in Western Europe, pro-welfare and egalitarian distributional views are primarily motivated by conventionality-driven norm adherence in postsocialist countries in the form of the mechanism of postsocialist economic system nostalgia. Our results highlight the benefits of a context-specific ’motivated social cognition’ approach to ideological and political attitudes. PMID:27247699

  14. Neural mechanisms underlying motivation of mental versus physical effort.

    Directory of Open Access Journals (Sweden)

    Liane Schmidt

    2012-02-01

    Full Text Available Mental and physical efforts, such as paying attention and lifting weights, have been shown to involve different brain systems. These cognitive and motor systems, respectively, include cortical networks (prefronto-parietal and precentral regions as well as subregions of the dorsal basal ganglia (caudate and putamen. Both systems appeared sensitive to incentive motivation: their activity increases when we work for higher rewards. Another brain system, including the ventral prefrontal cortex and the ventral basal ganglia, has been implicated in encoding expected rewards. How this motivational system drives the cognitive and motor systems remains poorly understood. More specifically, it is unclear whether cognitive and motor systems can be driven by a common motivational center or if they are driven by distinct, dedicated motivational modules. To address this issue, we used functional MRI to scan healthy participants while performing a task in which incentive motivation, cognitive, and motor demands were varied independently. We reasoned that a common motivational node should (1 represent the reward expected from effort exertion, (2 correlate with the performance attained, and (3 switch effective connectivity between cognitive and motor regions depending on task demand. The ventral striatum fulfilled all three criteria and therefore qualified as a common motivational node capable of driving both cognitive and motor regions of the dorsal striatum. Thus, we suggest that the interaction between a common motivational system and the different task-specific systems underpinning behavioral performance might occur within the basal ganglia.

  15. Torque Control of Underactuated Tendon-driven Robotic Fingers

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  16. Depletion of proton motive force by nisin in Listeria monocytogenes cells.

    Science.gov (United States)

    Bruno, M E; Kaiser, A; Montville, T J

    1992-07-01

    The basal proton motive force (PMF) levels and the influence of the bacteriocin nisin on the PMF were determined in Listeria monocytogenes Scott A. In the absence of nisin, the interconversion of the pH gradient (Z delta pH) and the membrane potential (delta psi) led to the maintenance of a fairly constant PMF at -160 mV over the external pH range 5.5 to 7.0. The addition of nisin at concentrations of greater than or equal to 5 micrograms/ml completely dissipated PMF in cells at external pH values of 5.5 and 7.0. With 1 microgram of nisin per ml, delta pH was completely dissipated but delta psi decreased only slightly. The action of nisin on PMF in L. monocytogenes Scott A was both time and concentration dependent. Valinomycin depleted only delta pH, whereas nigericin and carbonyl cyanide m-chlorophenylhydrazone depleted only delta psi, under conditions in which nisin depleted both. Four other L. monocytogenes strains had basal PMF parameters similar to those of strain Scott A. Nisin (2.5 micrograms/ml) also completely dissipated PMF in these strains.

  17. The Effect of Jigsaw Technique on 6th Graders' Learning of Force and Motion Unit and Their Science Attitudes and Motivation

    Science.gov (United States)

    Ural, Evrim; Ercan, Orhan; Gençoglan, Durdu Mehmet

    2017-01-01

    The study aims to investigate the effects of jigsaw technique on 6th graders' learning of "Force and Motion" unit, their science learning motivation and their attitudes towards science classes. The sample of the study consisted of 49 6th grade students from two different classes taking the Science and Technology course at a government…

  18. Mechanisms of DNA uptake by cells

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1977-01-01

    Three categories of cellular uptake of DNA can be distinguished. First, in the highly transformable bacteria, such as Diplococcus pneumoniae, Haemophilus influenzae and Bacillus subtilis, elaborate mechanisms of DNA transport have evolved, presumably for the purpose of genetic exchange. These mechanisms can introduce substantial amounts of DNA into the cell. Second, methods have been devised for the forced introduction of DNA by manipulation of bacterial cells under nonphysiological conditions. By such means small but significant amounts of DNA have been introduced into various bacteria, including Escherichia coli. Third, mammalian cells are able to take up biologically active DNA. This has been most clearly demonstrated with viral DNA, although the mechanism of uptake is not well understood. The intention, here, is to survey current understanding of the various mechanisms of DNA uptake. A review of experience with the bacterial systems may throw some light on the mammalian system and lead to suggestions for enhancing DNA uptake by mammalian cells.

  19. Data Driven, Force Based Interaction for Quadrotors

    Science.gov (United States)

    McKinnon, Christopher D.

    Quadrotors are small and agile, and are becoming more capable for their compact size. They are expected perform a wide variety of tasks including inspection, physical interaction, and formation flight. In all of these tasks, the quadrotors can come into close proximity with infrastructure or other quadrotors, and may experience significant external forces and torques. Reacting properly in each case is essential to completing the task safely and effectively. In this thesis, we develop an algorithm, based on the Unscented Kalman Filter, to estimate such forces and torques without making assumptions about the source of the forces and torques. We then show in experiment how the proposed estimation algorithm can be used in conjunction with controls and machine learning to choose the appropriate actions in a wide variety of tasks including detecting downwash, tracking the wind induced by a fan, and detecting proximity to the wall.

  20. Micromechanical Resonator Driven by Radiation Pressure Force.

    Science.gov (United States)

    Boales, Joseph A; Mateen, Farrukh; Mohanty, Pritiraj

    2017-11-22

    Radiation pressure exerted by light on any surface is the pressure generated by the momentum of impinging photons. The associated force - fundamentally, a quantum mechanical aspect of light - is usually too small to be useful, except in large-scale problems in astronomy and astrodynamics. In atomic and molecular optics, radiation pressure can be used to trap or cool atoms and ions. Use of radiation pressure on larger objects such as micromechanical resonators has been so far limited to its coupling to an acoustic mode, sideband cooling, or levitation of microscopic objects. In this Letter, we demonstrate direct actuation of a radio-frequency micromechanical plate-type resonator by the radiation pressure force generated by a standard laser diode at room temperature. Using two independent methods, the magnitude of the resonator's response to forcing by radiation pressure is found to be proportional to the intensity of the incident light.

  1. Motivation and Adult Education.

    Science.gov (United States)

    Taylor, J. Rodney

    1982-01-01

    The author reviews theories of human motivation: Lewin's force field analysis, Skinner's operant reinforcement theory, and Maslow's hierarchy of needs. He then extracts the implications of these theories for adult learning. SK)

  2. Motivational and Ideological Underpinnings of Welfare Preferences in Eastern and Western Europe

    Directory of Open Access Journals (Sweden)

    Márton Hadarics

    2016-02-01

    Full Text Available In our study we investigated the motivational and ideological correlates of the approval of welfare services in postsocialist Central Eastern and Western Europe. In the centre of our inquiry stood how the motivations of selflessness and conventionality, along with distributional justice principles, are related to our welfare preferences beyond our rational self-interest, furthermore, how these associations depend on social-cultural circumstances. We have found that the motivational background of egalitarian economic and welfare attitudes are substantially different in the two regions. While beside of the rationalisation of self-interest, it seems to be related to selflessness-driven solidarity in Western Europe, pro-welfare and egalitarian distributional views are primarily motivated by conventionality-driven norm adherence in postsocialist countries in the form of the mechanism of postsocialist economic system nostalgia. Our results highlight the benefits of a context-specific ’motivated social cognition’ approach to ideological and political attitudes.

  3. A vigorous Mesoamerican monsoon during the Last Glacial Maximum driven by orbital and oceanic forcing

    Science.gov (United States)

    Lachniet, M. S.; Asmerom, Y.; Bernal, J. P.; Polyak, V.; Vazquez-Selem, L. V.

    2012-12-01

    The external forcings on global monsoon strength include summer orbital insolation and ocean circulation changes, both of which are key control knobs on Earth's climate. However, few records of the North American Monsoon (NAM) are available to test its sensitivity to variations in the precession-dominated insolation signal and Atlantic Meridional Overturning Circulation (AMOC) for the Last Glacial Maximum (LGM; 21 ± 3 cal ka BP) and deglacial periods. In particular, well-dated and high-resolution records from the southern sector of the NAM, referred to informally as the Mesoamerican monsoon to distinguish it from the more northerly 'core' NAM, are needed to better elucidate paleoclimate change in North America. Here, we present a 22 ka (ka = kilo years) rainfall history from absolutely-dated speleothems from tropical southwestern Mexico that documents a vigorous LGM summer monsoon, in contradiction to previous interpretations, and that the monsoon collapsed during the Heinrich stadial 1 and Younger Dryas cold events. We conclude that a strong Mesoamerican monsoon requires both a large ocean-to-land temperature contrast, driven as today by summer insolation, and a proximal latitudinal position of the Intertropical Convergence Zone, forced by active AMOC.

  4. Droplet spreading driven by van der Waals force: a molecular dynamics study

    KAUST Repository

    Wu, Congmin

    2010-07-07

    The dynamics of droplet spreading is investigated by molecular dynamics simulations for two immiscible fluids of equal density and viscosity. All the molecular interactions are modeled by truncated Lennard-Jones potentials and a long-range van der Waals force is introduced to act on the wetting fluid. By gradually increasing the coupling constant in the attractive van der Waals interaction between the wetting fluid and the substrate, we observe a transition in the initial stage of spreading. There exists a critical value of the coupling constant, above which the spreading is pioneered by a precursor film. In particular, the dynamically determined critical value quantitatively agrees with that determined by the energy criterion that the spreading coefficient equals zero. The latter separates partial wetting from complete wetting. In the regime of complete wetting, the radius of the spreading droplet varies with time as R(t) ∼ √t, a behavior also found in molecular dynamics simulations where the wetting dynamics is driven by the short-range Lennard-Jones interaction between liquid and solid. © 2010 IOP Publishing Ltd.

  5. Employee motivation and employee performance in child care : the effects of the introduction of market forces on employees in the Dutch child-care sector

    NARCIS (Netherlands)

    Plantinga, Mirjam

    2006-01-01

    Employee Motivation and Employee Performance in Child Care: The Effects of the Introduction of Market Focus on Employees in the Dutch Child-Care Sector Mirjam Plantinga (RUG) This research describes and explains the effects of the introduction of market forces in the Dutch child-care sector on

  6. Employee Motivation and Employee Performance in Child Care : The effects of the Introduction of Market Forces on Employees in the Dutch Child-Care Sector

    NARCIS (Netherlands)

    Plantinga, Mirjam

    2006-01-01

    This research describes and explains the effects of the introduction of market forces in the Dutch child-care sector on employee governance, motivation and performance. The Dutch child-care sector is transitioning from a welfare sector into a market sector. The transition process in child care is

  7. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    Energy Technology Data Exchange (ETDEWEB)

    Su, Dongxu, E-mail: sudx@iis.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Tokyo 1538505 (Japan); Zheng, Rencheng; Nakano, Kimihiko [Institute of Industrial Science, The University of Tokyo, Tokyo 1538505 (Japan); Cartmell, Matthew P [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2014-11-15

    Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation.

  8. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    International Nuclear Information System (INIS)

    Su, Dongxu; Zheng, Rencheng; Nakano, Kimihiko; Cartmell, Matthew P

    2014-01-01

    Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation

  9. Spin-motive Force Induced by Domain Wall Dynamics in the Antiferromagnetic Spin Valve

    Science.gov (United States)

    Sugano, Ryoko; Ichimura, Masahiko; Takahashi, Saburo; Maekawa, Sadamichi; Crest Collaboration

    2014-03-01

    In spite of no net magnetization in antiferromagnetic (AF) textures, the local magnetic properties (Neel magnetization) can be manipulated in a similar fashion to ferromagnetic (F) ones. It is expected that, even in AF metals, spin transfer torques (STTs) lead to the domain wall (DW) motion and that the DW motion induces spin-motive force (SMF). In order to study the Neel magnetization dynamics and the resultant SMF, we treat the nano-structured F1/AF/F2 junction. The F1 and F2 leads behave as a spin current injector and a detector, respectively. Each F lead is fixed in the different magnetization direction. Torsions (DW in AF) are introduced reflecting the fixed magnetization of two F leads. We simulated the STT-induced Neel magnetization dynamics with the injecting current from F1 to F2 and evaluate induced SMF. Based on the adiabatic electron dynamics in the AF texture, Langevin simulations are performed at finite temperature. This research was supported by JST, CREST, Japan.

  10. ENTREPRENEURIAL MOTIVATIONS: ARE WOMEN DRIVEN BY DIFFERENT MOTIVATORS THAN MEN? (I – THE LITERATURE

    Directory of Open Access Journals (Sweden)

    Alina Badulescu

    2010-07-01

    Full Text Available The present article has the goal to reveal the (eventually differences between entrepreneurial motivations between men and women, in the case of EU and Romania. In the first part, we make a brief research into the literature related to this subject, and in the second part we shall reveal the facts and figures in the EU and Romania.

  11. Why try (not to cry: Intra- and inter-personal motives for crying regulation

    Directory of Open Access Journals (Sweden)

    Gwenda eSimons

    2013-01-01

    Full Text Available This article discusses inter- and intra-personal motives for the regulation of crying, and presents illustrative findings from an online survey (N = 110 exploring why and how people regulate crying in their everyday lives. In line with current theorizing on emotion regulation and crying (e.g., Vingerhoets et al., 2000, we propose that emotional crying is regulated using both antecedent-focused techniques targeting the underlying emotion and response-focused techniques targeting the act of crying itself. Indeed, our survey respondents reported having used both antecedent- and response-focused strategies to either up-regulate or down-regulate their crying. Motives for crying regulation may be both inter- and intra-personal and may serve both immediate, pleasure motives and future, utility motives (Tamir, 2009. Our findings suggest that down-regulation attempts are often driven by inter-personal motives (e.g., protecting the well-being of others; impression management in addition to intra-personal motives such as maintaining subjective well-being, whereas up-regulation attempts are mostly driven by intra-personal motives. Further progress requires methodologies for manipulating or tracking regulation motives and strategies in real-time crying episodes.

  12. The Relationship between Motivation and Job Satisfaction of ...

    African Journals Online (AJOL)

    User

    Our findings revealed that motivation has strong impact on job satisfaction of retail ... high levels of productivity and return on investment. This is the fact .... opportunities of the retail business managers, attenuate their motivational force. Test of ...

  13. Exploring the role of motivational and coping resources in a Special Forces selection process

    Directory of Open Access Journals (Sweden)

    Marié de Beer

    2014-07-01

    Research purpose: The purpose was to compare selected and not-selected candidates in terms of their sense of coherence, hardiness, locus of control and self-efficacy and to explore what they considered important for success in the selection process. Motivation for the study: Because of high attrition rates in Special Forces selection, the evaluation of the role of motivation and coping resources in terms of possible predictive utility could benefit the organisation from a logistical, financial and efficiency point of view. Research design, approach and method: A mixed-method cross-sectional survey design was used to assess an all-male candidate group (N = 73. The selected and not-selected groups were compared with regard to their sense of coherence, hardiness, locus of control and self-efficacy mean scores. Main findings: No statistically significant differences were found between the mean scores of the two groups concerning the quantitative measures used. Practical/managerial implications: The quantitative measures generally showed acceptable coefficient alpha reliabilities. Although no statistically significant mean differences were found between the groups, candidates showed high levels of sense of coherence, high levels of self-efficacy and average levels of hardiness and internal locus of control. The qualitative data confirmed the relevance of the quantitative constructs and pointed to additional aspects already considered in preparation for and during the selection process. Contribution/value-add: The results provide information regarding the constructs and measures used in a military context.

  14. Porters and neurotransmitter transporters.

    Science.gov (United States)

    Nelson, N; Lill, H

    1994-11-01

    Uptake of neurotransmitters involves multiple transporters acting in different brain locations under different physiological conditions. The vesicular transporters are driven by a proton-motive force generated by a V-ATPase and their substrates are taken up via proton/substrate exchange. The plasma membrane transporters are driven by an electrochemical gradient of sodium generated by a Na+/K(+)-ATPase. Two distinct families of transporters were identified in this group. One cotransports sodium with glutamate and other amino acids and requires additionally an outwardly directed potassium gradient. The second cotransports sodium, chloride and a variety of neurotransmitters, including gamma-aminobutyric acid (GABA), glycine and monoamines. Genes and cDNA encoding several members of the latter family have been cloned and studied in detail. The structure and function as well as the evolutionary relationships among these neurotransmitter transporters are discussed.

  15. Influence of orbital forcing and solar activity on water isotopes in precipitation during the mid- and late Holocene

    Directory of Open Access Journals (Sweden)

    S. Dietrich

    2013-01-01

    Full Text Available In this study we investigate the impact of mid- and late Holocene orbital forcing and solar activity on variations of the oxygen isotopic composition in precipitation. The investigation is motivated by a recently published speleothem δ18O record from the well-monitored Bunker Cave in Germany. The record reveals some high variability on multi-centennial to millennial scales that does not linearly correspond to orbital forcing. Our model study is based on a set of novel climate simulations performed with the atmosphere general circulation model ECHAM5-wiso enhanced by explicit water isotope diagnostics. From the performed model experiments, we derive the following major results: (1 the response of both orbital and solar forcing lead to changes in surface temperatures and δ18O in precipitation with similar magnitudes during the mid- and late Holocene. (2 Past δ18O anomalies correspond to changing temperatures in the orbital driven simulations. This does not hold true if an additional solar forcing is added. (3 Two orbital driven mid-Holocene experiments, simulating the mean climate state approximately 5000 and 6000 yr ago, yield very similar results. However, if an identical additional solar activity-induced forcing is added, the simulated changes of surface temperatures as well as δ18O between both periods differ. We conclude from our simulation results that non-linear effects and feedbacks of the orbital and solar activity forcing substantially alter the δ18O in precipitation pattern and its relation to temperature change.

  16. Enhanced cerebral uptake of receptor ligands by modulation of P-glycoprotein function in the blood-brain barrier

    NARCIS (Netherlands)

    Doze, P; Van Waarde, A; Elsinga, P H; Hendrikse, N H; Vaalburg, W

    Low cerebral uptake of some therapeutic drugs can be enhanced by modulation of P-glycoprotein (P-gp), an ATP-driven drug efflux pump at the blood-brain barrier (BBB). We investigated the possibility of increasing cerebral uptake of the beta-adrenergic ligands S-1'-[(18)F]-fluorocarazolol (FCAR) and

  17. Pharmacy Educator Motives to Pursue Pedagogical Knowledge.

    Science.gov (United States)

    Baia, Patricia; Strang, Aimee F

    2016-10-25

    Objective. To investigate motives of pharmacy educators who pursue pedagogical knowledge through professional development programs and to develop a model of motivation to inform future development. Methods. A mixed-methods approach was used to study both qualitative and quantitative data. Written narratives, postmodule quizzes, and survey data were collected during a 5-year period (2010-2014) from pharmacy educators who participated in an online professional development program titled Helping Educators Learn Pedagogy (HELP). Grounded theory was used to create a model of motivation for why pharmacy educators might pursue pedagogical knowledge. Results. Participants reported being driven intrinsically by a passion for their own learning (self-centered motivation) and by the need to improve student learning (student-centered motivation) and extrinsically by program design, funding, and administrator encouragement. Conclusion. A new model of pharmacy educator motivation to pursue pedagogy knowledge, Pedagogical Knowledge Acquisition Theory (PKAT), emerged as a blended intrinsic and extrinsic model, which may have value in developing future professional development programs.

  18. Shiga Toxin—A Model for Glycolipid-Dependent and Lectin-Driven Endocytosis

    Directory of Open Access Journals (Sweden)

    Ludger Johannes

    2017-10-01

    Full Text Available The cellular entry of the bacterial Shiga toxin and the related verotoxins has been scrutinized in quite some detail. This is due to their importance as a threat to human health. At the same time, the study of Shiga toxin has allowed the discovery of novel molecular mechanisms that also apply to the intracellular trafficking of endogenous proteins at the plasma membrane and in the endosomal system. In this review, the individual steps that lead to Shiga toxin uptake into cells will first be presented from a purely mechanistic perspective. Membrane-biological concepts will be highlighted that are often still poorly explored, such as fluctuation force-driven clustering, clathrin-independent membrane curvature generation, friction-driven scission, and retrograde sorting on early endosomes. It will then be explored whether and how these also apply to other pathogens, pathogenic factors, and cellular proteins. The molecular nature of Shiga toxin as a carbohydrate-binding protein and that of its cellular receptor as a glycosylated raft lipid will be an underlying theme in this discussion. It will thereby be illustrated how the study of Shiga toxin has led to the proposal of the GlycoLipid-Lectin (GL-Lect hypothesis on the generation of endocytic pits in processes of clathrin-independent endocytosis.

  19. Public Values and Public Service Motivation

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Beck Jørgensen, Torben; Kjeldsen, Anne Mette

    2013-01-01

    The literatures on public values (PV) and public service motivation (PSM) both address whether public service delivery is driven by something more than self-interest. They have developed separately, although they can benefit from insights developed by the other, and this article discusses...... conceptual and empirical relationships between them. Based on a survey of 501 public managers, we find that PSM and PV are associated empirically, but not in a manner allowing total integration. The conceptual discussion reveals how the two concepts cannot be totally separated, as values can be motivating...

  20. EMGD-FE: an open source graphical user interface for estimating isometric muscle forces in the lower limb using an EMG-driven model.

    Science.gov (United States)

    Menegaldo, Luciano Luporini; de Oliveira, Liliam Fernandes; Minato, Kin K

    2014-04-04

    This paper describes the "EMG Driven Force Estimator (EMGD-FE)", a Matlab® graphical user interface (GUI) application that estimates skeletal muscle forces from electromyography (EMG) signals. Muscle forces are obtained by numerically integrating a system of ordinary differential equations (ODEs) that simulates Hill-type muscle dynamics and that utilises EMG signals as input. In the current version, the GUI can estimate the forces of lower limb muscles executing isometric contractions. Muscles from other parts of the body can be tested as well, although no default values for model parameters are provided. To achieve accurate evaluations, EMG collection is performed simultaneously with torque measurement from a dynamometer. The computer application guides the user, step-by-step, to pre-process the raw EMG signals, create inputs for the muscle model, numerically integrate the ODEs and analyse the results. An example of the application's functions is presented using the quadriceps femoris muscle. Individual muscle force estimations for the four components as well the knee isometric torque are shown. The proposed GUI can estimate individual muscle forces from EMG signals of skeletal muscles. The estimation accuracy depends on several factors, including signal collection and modelling hypothesis issues.

  1. Motivational Interviewing to Promote Long-Acting Reversible Contraception in Postpartum Teenagers.

    Science.gov (United States)

    Tomlin, Kristl; Bambulas, Tammalynn; Sutton, Maureen; Pazdernik, Vanessa; Coonrod, Dean V

    2017-06-01

    To determine if teenage patients receiving prenatal care in an adolescent-focused clinic, emphasizing long-acting reversible contraception (LARC) using motivational interviewing techniques, had higher rates of uptake of postpartum LARC than a control group. Retrospective cohort study comparing young women who received prenatal care in an adolescent-focused setting with those enrolled in standard prenatal care. Adolescents between the ages of 13 and 17 years receiving prenatal care within the Maricopa Integrated Health safety-net system between 2007 and 2014. Motivational interviewing within the context of adolescent-focused prenatal care. Rates of uptake of LARC within 13 postpartum weeks. The adjusted rate of LARC for adolescent-focused prenatal care participants by 13 weeks postpartum was 38% (95% confidence interval [CI], 29%-47%) compared with 18% (95% CI, 11%-28%) for standard care participants, with an adjusted odds ratio of LARC use of 2.8 (95% CI, 1.5-5.2). Among patients who received adolescent-focused prenatal care, most (27% vs 12.7%) were using an intrauterine device as opposed to an implantable contraceptive device. Participation in an adolescent-focused antepartum setting using motivational interviewing to emphasize postpartum LARC resulted in nearly 3 times higher rates of uptake compared with standard prenatal care. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  2. Data-Driven Diffusion Of Innovations: Successes And Challenges In 3 Large-Scale Innovative Delivery Models.

    Science.gov (United States)

    Dorr, David A; Cohen, Deborah J; Adler-Milstein, Julia

    2018-02-01

    Failed diffusion of innovations may be linked to an inability to use and apply data, information, and knowledge to change perceptions of current practice and motivate change. Using qualitative and quantitative data from three large-scale health care delivery innovations-accountable care organizations, advanced primary care practice, and EvidenceNOW-we assessed where data-driven innovation is occurring and where challenges lie. We found that implementation of some technological components of innovation (for example, electronic health records) has occurred among health care organizations, but core functions needed to use data to drive innovation are lacking. Deficits include the inability to extract and aggregate data from the records; gaps in sharing data; and challenges in adopting advanced data functions, particularly those related to timely reporting of performance data. The unexpectedly high costs and burden incurred during implementation of the innovations have limited organizations' ability to address these and other deficits. Solutions that could help speed progress in data-driven innovation include facilitating peer-to-peer technical assistance, providing tailored feedback reports to providers from data aggregators, and using practice facilitators skilled in using data technology for quality improvement to help practices transform. Policy efforts that promote these solutions may enable more rapid uptake of and successful participation in innovative delivery system reforms.

  3. Student Motivation for Involvement in Supervised Agricultural Experiences: An Historical Perspective

    Science.gov (United States)

    Bird, William A.; Martin, Michael J.; Simonsen, Jon C.

    2013-01-01

    The purpose of this study was to examine student motivation for SAEs through the lens of the Self-Determination Theory. Self-Determination Theory proposed that human beings are more genuinely motivated when driven by internal factors as opposed to external factors. We used historical research and general qualitative interpretative methods to…

  4. "FACILS 2014: Microbially-driven facilitation systems in environmental biotechnology" (hereafter "FACILS") presented here by the European Commission (EC)-United States (US) Task Force on Biotechnology Research

    Energy Technology Data Exchange (ETDEWEB)

    Methe, Barbara

    2016-02-03

    As we enter the 21st century, the sustainability of the biosphere is a global challenge that can best be met with a global response. This includes how we train and promote our next generation of research scientists in the emerging arenas of genome-enabled biology and a bio-based economy. It is this fundamental issue that formed the motivation for designing and conducting a shortcourse entitled “FACILIS 2014: Microbially-driven facilitation systems in environmental biotechnology” (hereafter “FACILIS”) presented here by the European Commission (EC)-United States (US) Task Force on Biotechnology Research. This WG was established in 1994 under the umbrella of the US-EC Task Force on Biotechnology Research, a transatlantic collaborative group overseen by the US Office of Science and Technology Policy (OSTP) and the EC. The Environmental Biotechnology Working Group maintains several goals, including establishing research links between scientists in EU countries and the US and fostering the careers of junior scientists from both sides of the Atlantic to the global nature of scientific cooperation. To that end, a shortcourse was held at the University of Milan in Italy on July 12-25 2014 organized around cross-cutting themes of genomic science and designed to attract a stellar group of interdisciplinary early carrier researchers. A total of 22 students, 10 from the US and 12 from the EU participated. The course provided them with hands-on experience with the latest scientific methods in genomics and bioinformatics; using a format that combines lectures, laboratory research and field work with the final goal to enable researchers to finally turn data into knowledge.

  5. Dynamic force microscopy with quartz tuning forks at high oscillation amplitudes

    International Nuclear Information System (INIS)

    Labardi, M

    2007-01-01

    Dynamic force microscopy (DFM) with the self-oscillator (SO) method allows reasonably high scanning rates even with high Q-factors of the resonant force sensor, typical of cantilevers in ultra-high vacuum and of quartz tuning forks. However, due to simpler interpretation of force spectroscopy measurements, small oscillation amplitudes (sub-nm level) are generally preferred. In applications like 'apertureless' scanning near-field optical microscopy (SNOM), oscillation amplitudes of the order of 5-10 nm are needed to increase optical sensitivity and to apply standard optical artefact suppression methods. This motivates the study of the behaviour of tuning forks driven at such high amplitudes, as compared to usual air-operated cantilevers. Both constant-excitation-amplitude (CE) and constant-oscillation-amplitude (CA) modes of SO-DFM are analysed, since the CA mode is more convenient for SNOM applications, denoting remarkable differences. In particular, possible instability effects, previously found in CE mode, are not anticipated for CA mode. It is shown how resonance and approach ('isophase') curves in both modes can be conveniently described in terms of the usual 'normalized frequency shift' γ and of a 'normalized gain' η, defined as a measurement of surface dissipation

  6. Analyzing EFL Teachers’ Initial Job Motivation and Factors Effecting Their Motivation in Fezalar Educational Institutions in Iraq

    Directory of Open Access Journals (Sweden)

    Selcuk Koran

    2015-02-01

    Full Text Available Teacher motivation is one of the primary variables of students’ high performance. It is experienced that students whose teachers are highly motivated are more engaged in the learning process. Therefore, it’s mostly the teacher who determines the level of success or failure in achieving institution’s goal in the educational process. Thus, teachers are expected to demonstrate a high job motivation performance by administrations. However, some teachers seem naturally enthusiastic about teaching while others need to be stimulated, inspired and challenged. There are several factors that provide teachers with necessary motivation driven by which they can work effectively. These factors can be emotional, financial, physical or academic. This study is an attempt to find out what motivates teachers to enter this profession, since the reasons of entering this job has significant influence on their commitment to the job, investigate factors which are responsible for high or low motivation of language teachers in Fezalar Educational Institutions (FEI, which is a Turkish private institution that operates in Iraq, and ascertain the degree to which intrinsic and extrinsic motivational factors impact teachers in their work situation. Based on the review of the recent researches of motivation, in general, and of language teacher motivation, in particular, and relying on the qualitative and quantitative study of the issue, a detailed analysis of some aspects of foreign language teacher motivation is presented in the article. Keywords: teacher motivation, job satisfaction, foreign language teaching, L2 teacher motivation

  7. Short-range fundamental forces

    International Nuclear Information System (INIS)

    Antoniadis, I.; Baessler, S.; Buchner, M.; Fedorov, V.V.; Hoedl, S.; Nesvizhevsky, V.V.; Pignol, G.; Protasov, K.V.; Lambrecht, A.; Reynaud, S.; Sobolev, Y.

    2010-01-01

    We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces; 2) spin-dependent axion-like forces. Different experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experiments. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments

  8. Applications of laser-driven particle acceleration

    CERN Document Server

    Parodi, Katia; Schreiber, Jorg

    2018-01-01

    The first book of its kind to highlight the unique capabilities of laser-driven acceleration and its diverse potential, Applications of Laser-Driven Particle Acceleration presents the basic understanding of acceleration concepts and envisioned prospects for selected applications. As the main focus, this new book explores exciting and diverse application possibilities, with emphasis on those uniquely enabled by the laser driver that can also be meaningful and realistic for potential users. A key aim of the book is to inform multiple, interdisciplinary research communities of the new possibilities available and to inspire them to engage with laser-driven acceleration, further motivating and advancing this developing field. Material is presented in a thorough yet accessible manner, making it a valuable reference text for general scientific and engineering researchers who are not necessarily subject matter experts. Applications of Laser-Driven Particle Acceleration is edited by Professors Paul R. Bolton, Katia ...

  9. Using Self-Determination Theory to Understand Motivation Deficits in Schizophrenia: The ‘Why’ of Motivated Behavior

    Science.gov (United States)

    Gard, David E.; Sanchez, Amy H.; Starr, Jessica; Cooper, Shanna; Fisher, Melissa; Rowlands, Abby; Vinogradov, Sophia

    2014-01-01

    Self-Determination Theory (SDT) provides a model for understanding motivation deficits in schizophrenia, and recent research has focused on problems with intrinsic motivation. However, SDT emphasizes that motivated behavior results from three different factors: intrinsic motivators (facilitated by needs for autonomy, competency, and relatedness), extrinsic motivators (towards reward or away from punishment), or when intrinsic and extrinsic motivators are absent or thwarted a disconnect/disengagement occurs resulting in behavior driven by boredom or ‘passing time’. Using a novel approach to Ecological Momentary Assessment, we assessed the degree to which people with schizophrenia were motivated by these factors relative to healthy control participants. Forty-seven people with and 41 people without schizophrenia were provided with cell phones and were called four times a day for one week. On each call participants were asked about their goals, and about the most important reason motivating each goal. All responses were coded by independent raters (blind to group and hypotheses) on all SDT motivating factors, and ratings were correlated to patient functioning and symptoms. We found that, relative to healthy participants, people with schizophrenia reported goals that were: 1) less motivated by filling autonomy and competency needs, but equivalently motivated by relatedness; 2) less extrinsically rewarding, but equivalently motivated by punishment; 3) more disconnected/disengaged. Higher disconnected/disengaged goals were significantly associated with higher negative symptoms and lower functioning. These findings indicate several important leverage points for behavioral treatments and suggest the need for vigorous psychosocial intervention focusing on autonomy, competence, and reward early in the course of illness. PMID:24853060

  10. Using self-determination theory to understand motivation deficits in schizophrenia: the 'why' of motivated behavior.

    Science.gov (United States)

    Gard, David E; Sanchez, Amy H; Starr, Jessica; Cooper, Shanna; Fisher, Melissa; Rowlands, Abby; Vinogradov, Sophia

    2014-07-01

    Self-determination theory (SDT) provides a model for understanding motivation deficits in schizophrenia, and recent research has focused on problems with intrinsic motivation. However, SDT emphasizes that motivated behavior results from three different factors: intrinsic motivators (facilitated by needs for autonomy, competency, and relatedness), extrinsic motivators (towards reward or away from punishment), or when intrinsic and extrinsic motivators are absent or thwarted a disconnect-disengagement occurs resulting in behavior driven by boredom or 'passing time'. Using a novel approach to Ecological Momentary Assessment, we assessed the degree to which people with schizophrenia were motivated by these factors relative to healthy control participants. Forty-seven people with and 41 people without schizophrenia were provided with cell phones and were called four times a day for one week. On each call participants were asked about their goals, and about the most important reason motivating each goal. All responses were coded by independent raters (blind to group and hypotheses) on all SDT motivating factors, and ratings were correlated to patient functioning and symptoms. We found that, relative to healthy participants, people with schizophrenia reported goals that were: (1) less motivated by filling autonomy and competency needs, but equivalently motivated by relatedness; (2) less extrinsically rewarding, but equivalently motivated by punishment; (3) more disconnected-disengaged. Higher disconnected-disengaged goals were significantly associated with higher negative symptoms and lower functioning. These findings indicate several important leverage points for behavioral treatments and suggest the need for vigorous psychosocial intervention focusing on autonomy, competence, and reward early in the course of illness. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Dissipation and oscillatory solvation forces in confined liquids studied by small amplitude atomic force spectroscopy

    NARCIS (Netherlands)

    de Beer, Sissi; van den Ende, Henricus T.M.; Mugele, Friedrich

    2010-01-01

    We determine conservative and dissipative tip–sample interaction forces from the amplitude and phase response of acoustically driven atomic force microscope (AFM) cantilevers using a non-polar model fluid (octamethylcyclotetrasiloxane, which displays strong molecular layering) and atomically flat

  12. [Health behavior change: motivational interviewing].

    Science.gov (United States)

    Pócs, Dávid; Hamvai, Csaba; Kelemen, Oguz

    2017-08-01

    Public health data show that early mortality in Hungary could be prevented by smoking cessation, reduced alcohol consumption, regular exercise, healthy diet and increased adherence. Doctor-patient encounters often highlight these aspects of health behavior. There is evidence that health behavior change is driven by internal motivation rather than external influence. This finding has led to the concept of motivational interview, which is a person-centered, goal-oriented approach to counselling. The doctor asks targeted questions to elicit the patient's motivations, strengths, internal resources, and to focus the interview around these. The quality and quantity of the patient's change talk is related to better outcomes. In addition, the interview allows the patient to express ambivalent feelings and doubts about the change. The doctor should use various communication strategies to resolve this ambivalence. Furthermore, establishing a good doctor-patient relationship is the cornerstone of the motivational interview. An optimal relationship can evoke change talk and reduce the patient's resistance, which can also result in a better outcome. The goal of the motivational interview is to focus on the 'why' to change health behavior rather than the 'how', and to utilize internal motivation instead of persuasion. This is the reason why motivational interview has become a widely-accepted evidence based approach. Orv Hetil. 2017; 158(34): 1331-1337.

  13. Patterning in systems driven by nonlocal external forces.

    Science.gov (United States)

    Luneville, L; Mallick, K; Pontikis, V; Simeone, D

    2016-11-01

    This work focuses on systems displaying domain patterns resulting from competing external and internal dynamics. To this end, we introduce a Lyapunov functional capable of describing the steady states of systems subject to external forces, by adding nonlocal terms to the Landau Ginzburg free energy of the system. Thereby, we extend the existing methodology treating long-range order interactions, to the case of external nonlocal forces. By studying the quadratic term of this Lyapunov functional, we compute the phase diagram in the temperature versus external field and we determine all possible modulated phases (domain patterns) as a function of the external forces and the temperature. Finally, we investigate patterning in chemical reactive mixtures and binary mixtures under irradiation, and we show that the last case opens the path toward micro-structural engineering of materials.

  14. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: A multi-model linear feedback analysis

    OpenAIRE

    Roy Tilla; Bopp Laurent; Gehlen Marion; Schneider Birgitt; Cadule Patricia; Frölicher Thomas; Segschneider Jochen; Tijputra Jerry; Heinze Christoph; Joos Fortunat

    2011-01-01

    The increase in atmospheric CO2 over this century depends on the evolution of the oceanic air–sea CO2 uptake which will be driven by the combined response to rising atmospheric CO2 itself and climate change. Here the future oceanic CO2 uptake is simulated using an ensemble of coupled climate–carbon cycle models. The models are driven by CO2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high emission scenario. A linear feedback analysis successfully sep...

  15. Vorticity dipoles and a theoretical model of a finite force at the moving contact line singularity

    Science.gov (United States)

    Zhang, Peter; Devoria, Adam; Mohseni, Kamran

    2017-11-01

    In the well known works of Moffatt (1964) and Huh & Scriven (1971), an infinite force was reported at the moving contact line (MCL) and attributed to a non-integrable stress along the fluid-solid boundary. In our recent investigation of the boundary driven wedge, a model of the MCL, we find that the classical solution theoretically predicts a finite force at the contact line if the forces applied by the two boundaries that make up the corner are taken into consideration. Mathematically, this force can be obtained by the complex contour integral of the holomorphic vorticity-pressure function given by G = μω + ip . Alternatively, this force can also be found using a carefully defined real integral that incorporates the two boundaries. Motivated by this discovery, we have found that the rate of change in circulation, viscous energy dissipation, and viscous energy flux is also finite per unit contact line length. The analysis presented demonstrates that despite a singular stress and a relatively simple geometry, the no-slip semi-infinite wedge is capable of capturing some physical quantities of interest. Furthermore, this result provides a foundation for other challenging topics such as dynamic contact angle.

  16. Vaccinations against respiratory infections in Arabian Gulf countries: Barriers and motivators.

    Science.gov (United States)

    Alqahtani, Amani S; Bondagji, Daniah M; Alshehari, Abdullah A; Basyouni, Mada H; Alhawassi, Tariq M; BinDhim, Nasser F; Rashid, Harunor

    2017-06-16

    To study the uptake, barriers and motivators of influenza, pneumococcal, meningococcal and pertussis vaccines among members of public in Arabian Gulf countries. A cross-sectional survey among the Gulf Cooperation Council (GCC) countries' residents. Data collected electronically through a smartphone app. The survey variables aimed to investigate the respondents' awareness about vaccines against influenza, pneumococcal, meningococcal and pertussis infections. Collected data concerning the respondents' socio-demographic characteristics, their perception toward vaccine uptake and the factors that motivate or demotivate them from taking influenza vaccine. The data were analysed statistically using the SPSS v.23.0. Differences in the characteristics of users from different countries were quantified through bivariate analysis. Other important variables and controlling factors were studied using logistic regression. A total of 1812 respondents participated in the study. Their mean age was 27 years, 82% were male and 24% had ≥ 1 chronic diseases. The overall uptake of influenza vaccine was 17% (21% among "at risk" people) and ranged from 15% in Saudi Arabia to 24% in Qatar. Doctor's advice (23%) and a perception of having low body immunity (21%) were the main cited reasons for being vaccinated, whereas unawareness about the vaccine (43%) was the main barrier. The overall uptake of pneumococcal vaccine in the preceding three years was 22% (25% among "at risk" individuals) and ranged from 0% in Bahrain to 79% in Kuwait. The overall uptake of pertussis vaccine was 16% (31% among "vulnerable" people), and ranged from 7% in Saudi Arabia to 75% in Oman. The overall uptake of meningococcal vaccine was 20% (29% among the "at risk" people) and ranged from 3% in Oman to 50% in Bahrain. The vaccination uptake across GCC countries is suboptimal and varies widely across the countries. Further research is needed to unearth the reasons and formulate action plan.

  17. Erythromycin and azithromycin transport into Haemophilus influenzae ATCC 19418 under conditions of depressed proton motive force (delta mu H)

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco, J.O.; Goldman, R.C. (Abbott Laboratories, IL (USA))

    1990-09-01

    The effect of collapsing the electrochemical proton gradient (delta mu H) on ({sup 3}H)erythromycin and ({sup 14}C)azithromycin transport in Haemophilus influenzae ATCC 19418 was studied. The proton gradient and membrane potential were determined from the distribution of (2-{sup 14}C)dimethadione and rubidium-86, respectively. delta mu H was reduced from 124 to 3 mV in EDTA-valinomycin-treated cells at 22{degrees}C with 150 mM KCl and 0.1 mM carbonyl cyanide m-chlorophenylhydrazone. During the collapse of delta mu H, macrolide uptake increased. Erythromycin efflux studies strongly suggested that this increase was not due to an energy-dependent efflux pump but was likely due to increased outer membrane permeability. These data indicated that macrolide entry was not a delta mu H-driven active transport process but rather a passive diffusion process.

  18. A data-driven alternative to the fractional Fokker–Planck equation

    International Nuclear Information System (INIS)

    Pressé, Steve

    2015-01-01

    Anomalous diffusion processes are ubiquitous in biology and arise in the transport of proteins, vesicles and other particles. Such anomalously diffusive behavior is attributed to a number of factors within the cell including heterogeneous environments, active transport processes and local trapping/binding. There are a number of microscopic principles—such as power law jump size and/or waiting time distributions—from which the fractional Fokker–Planck equation (FFPE) can be derived and used to provide mechanistic insight into the origins of anomalous diffusion. On the other hand, it is fair to ask if other microscopic principles could also have given rise to the evolution of an observed density profile that appears to be well fit by an FFPE. Here we discuss another possible mechanistic alternative that can give rise to densities like those generated by FFPEs. Rather than to fit a density (or concentration profile) using a solution to the spatial FFPE, we reconstruct the profile generated by an FFPE using a regular FPE with a spatial and time-dependent force. We focus on the special case of the spatial FFPE for superdiffusive processes. This special case is relevant to, for example, active transport in a biological context. We devise a prescription for extracting such forces on synthetically generated data and provide an interpretation to the forces extracted. In particular, the time-dependence of forces could tell us about ATP depletion or changes in the cell's metabolic activity. Modeling anomalous behavior with normal diffusion driven by these effective forces yields an alternative mechanistic picture that, ultimately, could help motivate future experiments. (paper)

  19. The "Uptake" of a Sport-for-Development Programme in South Africa

    Science.gov (United States)

    Burnett, Cora

    2015-01-01

    This article reports on the "uptake" dynamics and resultant manifestations of a school-based, incentive-driven, sport-for-development programme in the South African context of poverty. The ecological systems theory of Brofenbrenner, the theory of complexity and a neo-liberal framework underpin the social constructions of local meanings…

  20. Reconstruction of driving forces through recurrence plots

    International Nuclear Information System (INIS)

    Tanio, Masaaki; Hirata, Yoshito; Suzuki, Hideyuki

    2009-01-01

    We consider the problem of reconstructing one-dimensional driving forces only from the observations of driven systems. We extend the approach presented in a seminal paper [M.C. Casdagli, Physica D 108 (1997) 12] and propose a method that is robust and has wider applicability. By reinterpreting the work of Thiel et al. [M. Thiel, M.C. Romano, J. Kurths, Phys. Lett. A 330 (2004) 343], we formulate the reconstruction problem as a combinatorial optimization problem and relax conditions by assuming that a driving force is continuous. The method is demonstrated by using a tent map driven by an external force.

  1. The Role of Motivation in Language Learning

    Institute of Scientific and Technical Information of China (English)

    李玉红

    2004-01-01

    The role of motivation in language learning has been studied since the 1960s. It is indeed one of the most important areas of linguistics. This paper suggests strategies of motivating language learners and focuses on the role which motivation can play in language learning. The concept of motivation from different points of view is defined, a number of suggestions on how to motivate language learners are presented and the role of motivation based on various motivational theories are highlighted. With regard to the role of motivation in language learning, it is concluded that motivation plays an increasingly important role in many aspects, such as identifying with the target language society, achieving long-term and short-term goals, improving language learners' internal and external powers and exerting a group force. It also indicates that there should be more research areas to be examined and a long way is probably requlred to go in future theoretical and practical study.

  2. Motivators and barriers to uptake of post-operative voluntary medical male circumcision follow-up in Yala division, Siaya County, Kenya.

    Science.gov (United States)

    Abunah, Bonface; Onkoba, Rueben; Nyagero, Josephat; Muhula, Samuel; Omondi, Edward; Guyah, Bernard; Omondi, Gregory Barnabas

    2016-01-01

    Follow-up visits are recommended to all voluntary medical male circumcision clients (VMMC), however, adherence is variable. High lost-to-follow-up cases limit knowledge about clinical status of clients and adverse events. This study sought to establish Motivators and Barriers to the Uptake of VMMC post-operative follow-up services in Siaya County, Kenya. 277 clients from five VMMC sites in Yala were recruited immediately post-operation to participate in a telephone interview between the 21st and 31st day post-surgery during which a semi-structured questionnaire was administered. Descriptive and inferential statistics was used to analyse quantitative information using SPSS while responses from open ended questions were grouped into themes, sieved out, coded and analyzed. 137(49.5%) of the 277 participants utilized the follow-up services. Health education (31.4%) and emergency reviews/adverse events (24.1%) were the main motivation for returning for follow-up while occupational and other engagements (29.7%) and presumption of healing (24.6%) were the main barriers. Type of facility attended (p=0.0173), satisfaction with the discharge process (p=0.0150) and residency in Yala (p<0.001) were statistically significant to the respondents' return for follow-up. 85(62.0%) of the participants returned on the 7th day, 9(6.6%) returned after 7 days, and 43(31.4%) returned before 7 days. VMMC health education should include and emphasize the benefits of follow-up care to the clients and the providers should address the barriers to accessing follow-up services. Our results will inform the programme on areas identified to improve care for VMMC clients and reduce subsequent lost-to-follow-up cases.

  3. Optimal Design of a 3-DOF Cable-Driven Upper Arm Exoskeleton

    Directory of Open Access Journals (Sweden)

    Zhu-Feng Shao

    2014-04-01

    Full Text Available With outstanding advantages, such as large workspace, flexibility, and lightweight and low inertia, cable-driven parallel manipulator shows great potential for application as the exoskeleton rehabilitation robot. However, the optimal design is still a challenging problem to be solved. In this paper, the optimal design of a 3-DOF (3-degree-of-freedom cable-driven upper arm exoskeleton is accomplished considering the force exerted on the arm. After analysis of the working conditions, two promising configurations of the cable-driven upper arm exoskeleton are put forward and design parameters are simplified. Then, candidate ranges of two angle parameters are determined with the proposed main workspace requirement. Further, global force indices are defined to evaluate the force applied to the arm by the exoskeleton, in order to enhance the system safety and comfort. Finally, the optimal design of each configuration is obtained with proposed force indices. In addition, atlases and charts given in this paper well illustrate trends of workspace and force with different values of design parameters.

  4. How emotion context modulates unconscious goal activation during motor force exertion.

    Science.gov (United States)

    Blakemore, Rebekah L; Neveu, Rémi; Vuilleumier, Patrik

    2017-02-01

    Priming participants with emotional or action-related concepts influences goal formation and motor force output during effort exertion tasks, even without awareness of priming information. However, little is known about neural processes underpinning how emotional cues interact with action (or inaction) goals to motivate (or demotivate) motor behaviour. In a novel functional neuroimaging paradigm, visible emotional images followed by subliminal action or inaction word primes were presented before participants performed a maximal force exertion. In neutral emotional contexts, maximum force was lower following inaction than action primes. However, arousing emotional images had interactive motivational effects on the motor system: Unpleasant images prior to inaction primes increased force output (enhanced effort exertion) relative to control primes, and engaged a motivation-related network involving ventral striatum, extended amygdala, as well as right inferior frontal cortex. Conversely, pleasant images presented before action (versus control) primes decreased force and activated regions of the default-mode network, including inferior parietal lobule and medial prefrontal cortex. These findings show that emotional context can determine how unconscious goal representations influence motivational processes and are transformed into actual motor output, without direct rewarding contingencies. Furthermore, they provide insight into altered motor behaviour in psychopathological disorders with dysfunctional motivational processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Elephant overflows: Multi-annual variability in Weddell Sea Deep Water driven by surface forcing

    Science.gov (United States)

    Meijers, Andrew; Meredith, Michael; Abrahamsen, Povl; Naviera-Garabato, Alberto; Ángel Morales Maqueda, Miguel; Polzin, Kurt

    2015-04-01

    The volume of the deepest and densest water mass in Drake Passage, Lower Weddell Sea Deep Water (LWSDW), is shown to have been decreasing over the last 20 years of observations, with an associated reduction in density driven by freshening. Superimposed on this long term trend is a multi-annual oscillation with a period of 3-5 years. This variability only appears in Drake Passage; observations in the east of the Scotia Sea show a similar long term trend, but with no apparent multi-annual variability. Clues as to the source of this variability may be found on the continental slope at approximately 1000 m immediately north of Elephant Island on the northern tip of the Antarctic Peninsula. Here there is an intermittent westward flowing cold/fresh slope current whose volume and properties are strongly correlated with the LWSDW multi-annual variability, although leading the LWSDW by around one year. As the slope current and LWSDW are separated from each other both geographically and in water mass characteristics, their co-variability implies that they are responding to a common forcing, while the lag between deep LWSDW and shallow slope current provides information on the timescale of this response. A newly available high resolution temperature and salinity multi-year time series from the Elephant Island slope at 1000 m is compared with reanalysis and model derived surface fluxes, sea ice extent and wind stress. We find that there are strong positive relationships between the surface wind stress and heat flux over the shelf at the tip of the Antarctic Peninsula and the properties of the slope current at 1000 m on seasonal to annual timescales. We use tracer release experiments in the Southern Ocean State Estimate (SOSE) model to investigate the lag between the slope current and LWSDW timeseries and hypothesise that the observed multi-annual variability in both water masses is driven by surface forcing over the shelf and the overflow of modified water from the slope in

  6. Motives for offending among violent and psychotic men.

    Science.gov (United States)

    Taylor, P J

    1985-11-01

    Two hundred and three male remanded prisoners were interviewed with respect to their current offence, mental state, and social and psychiatric histories. All but nine of the sub-group of 121 psychotic men showed active symptoms at the time of committing a criminal offence; 20% of the actively ill psychotics were directly driven to offend by their psychotic symptoms, and a further 26% probably so. If some of the indirect consequences of the psychosis were taken into account, 82% of their offences were probably attributable to the illness. Among the normal and neurotic men, none claimed psychotic motives for offending, but motives suggesting high emotional arousal such as panic or retaliation triggered the greatest violence. Within the psychotic group, those driven to offend by their delusions were most likely to have been seriously violent, and psychotic symptoms probably accounted directly for most of the very violent behaviour.

  7. Effects of robotically modulating kinematic variability on motor skill learning and motivation.

    Science.gov (United States)

    Duarte, Jaime E; Reinkensmeyer, David J

    2015-04-01

    It is unclear how the variability of kinematic errors experienced during motor training affects skill retention and motivation. We used force fields produced by a haptic robot to modulate the kinematic errors of 30 healthy adults during a period of practice in a virtual simulation of golf putting. On day 1, participants became relatively skilled at putting to a near and far target by first practicing without force fields. On day 2, they warmed up at the task without force fields, then practiced with force fields that either reduced or augmented their kinematic errors and were finally assessed without the force fields active. On day 3, they returned for a long-term assessment, again without force fields. A control group practiced without force fields. We quantified motor skill as the variability in impact velocity at which participants putted the ball. We quantified motivation using a self-reported, standardized scale. Only individuals who were initially less skilled benefited from training; for these people, practicing with reduced kinematic variability improved skill more than practicing in the control condition. This reduced kinematic variability also improved self-reports of competence and satisfaction. Practice with increased kinematic variability worsened these self-reports as well as enjoyment. These negative motivational effects persisted on day 3 in a way that was uncorrelated with actual skill. In summary, robotically reducing kinematic errors in a golf putting training session improved putting skill more for less skilled putters. Robotically increasing kinematic errors had no performance effect, but decreased motivation in a persistent way. Copyright © 2015 the American Physiological Society.

  8. The Motivational Interviewing Navigation Guide: A Process for Enhancing Teachers' Motivation to Adopt and Implement School-Based Interventions

    Science.gov (United States)

    Frey, Andy J.; Lee, Jon; Small, Jason W.; Seeley, John R.; Walker, Hill M.; Feil, Edward G.

    2013-01-01

    There is a critical need to engage theory-driven research related to the deployment of mental health promotion initiatives and student outcomes. A growing body of research supporting the use of motivational interviewing and engagement strategies in education suggests that this approach may be promising to better understand mechanisms through which…

  9. Role of compressibility on driven magnetic reconnection

    International Nuclear Information System (INIS)

    Sato, T.; Hayashi, T.; Watanabe, K.; Horiuchi, R.; Tanaka, M.; Sawairi, N.; Kusano, K.

    1991-08-01

    Whether it is induced by an ideal (current driven) instability or by an external force, plasma flow causes a change in the magnetic field configuration and often gives rise to a current intensification locally, thereby a fast driven reconnection being driven there. Many dramatic phenomena in magnetically confined plasmas such as magnetospheric substorms, solar flares, MHD self-organization and tokamak sawtooth crash, may be attributed to this fast driven reconnection. Using a fourth order MHD simulation code it is confirmed that compressibility of the plasma plays a crucial role in leading to a fast (MHD time scale) driven reconnection. This indicates that the incompressible representation is not always applicable to the study of a global dynamical behavior of a magnetically confined plasma. (author)

  10. Thermal creep force: analysis and application

    OpenAIRE

    Wolfe, David M.

    2016-01-01

    Approved for public release; distribution is unlimited The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force, in particular, has been subject to differing interpretations of the direction in which it acts and its order of magnitude. A horizontal vane radiometer design is provided, which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kin...

  11. Transmutation of fission products in reactors and accelerator-driven systems

    International Nuclear Information System (INIS)

    Janssen, A.J.

    1994-01-01

    Energy flows and mass flows in several scenarios are considered. Economical and safety aspects of the transmutation scenarios are compared. It is difficult to find a sound motivation for the transmutation of fission products with accelerator-driven systems. If there would be any hesitation in transmuting fission products in nuclear reactors, there would be an even stronger hesitation to use accelerator-driven systems, mainly because of their lower energy efficiency and their poor cost effectiveness. The use of accelerator-driven systems could become a 'meaningful' option only if nuclear energy would be banished completely. (orig./HP)

  12. Evanescent-wave proton postaccelerator driven by intense THz pulse

    OpenAIRE

    L. Pálfalvi; J. A. Fülöp; Gy. Tóth; J. Hebling

    2014-01-01

    Hadron therapy motivates research dealing with the production of particle beams with ∼100  MeV/nucleon energy and relative energy fluctuation on the order of 1%. Laser-driven accelerators produce ion beams with only tens of MeV/nucleon energy and an extremely broad spectra. Here, a novel method is proposed for postacceleration and monochromatization of particles, leaving the laser-driven accelerator, by using intense THz pulses. It is based on further developing the idea of using the evanesce...

  13. M-type thioredoxins are involved in the xanthophyll cycle and proton motive force to alter NPQ under low-light conditions in Arabidopsis.

    Science.gov (United States)

    Da, Qingen; Sun, Ting; Wang, Menglong; Jin, Honglei; Li, Mengshu; Feng, Dongru; Wang, Jinfa; Wang, Hong-Bin; Liu, Bing

    2018-02-01

    M-type thioredoxins are required to regulate zeaxanthin epoxidase activity and to maintain the steady-state level of the proton motive force, thereby influencing NPQ properties under low-light conditions in Arabidopsis. Non-photochemical quenching (NPQ) helps protect photosynthetic organisms from photooxidative damage via the non-radiative dissipation of energy as heat. Energy-dependent quenching (qE) is a major constituent of NPQ. However, the mechanism underlying the regulation of qE is not well understood. In this study, we demonstrate that the m-type thioredoxins TRX-m1, TRX-m2, and TRX-m4 (TRX-ms) interact with the xanthophyll cycle enzyme zeaxanthin epoxidase (ZE) and are required for maintaining the redox-dependent stabilization of ZE by regulating its intermolecular disulfide bridges. Reduced ZE activity and accumulated zeaxanthin levels were observed under TRX-ms deficiency. Furthermore, concurrent deficiency of TRX-ms resulted in a significant increase in proton motive force (pmf) and acidification of the thylakoid lumen under low irradiance, perhaps due to the significantly reduced ATP synthase activity under TRX-ms deficiency. The increased pmf, combined with acidification of the thylakoid lumen and the accumulation of zeaxanthin, ultimately contribute to the elevated stable qE in VIGS-TRX-m2m4/m1 plants under low-light conditions. Taken together, these results indicate that TRX-ms are involved in regulating NPQ-dependent photoprotection in Arabidopsis.

  14. Variation in summer nitrogen and phosphorus uptake among Siberian headwater streams

    Directory of Open Access Journals (Sweden)

    John D. Schade

    2016-06-01

    Full Text Available Arctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N and phosphorus (P uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia's Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher than N, while upland streams had similar values for all N and P uptake metrics. Phosphorus uptake velocity and size of the transient hydrologic storage zone were negatively related across all study streams, indicating strong influence of hydrologic processes on nutrient fluxes. Physical sorption of P was higher in floodplain stream sediments relative to upland stream sediments, suggesting more physically driven uptake in floodplain streams and higher biological activity in upland streams. Overall, these results demonstrate that high-latitude headwater streams actively retain N and P during summer base flows; however, floodplain and upland streams varied substantially in N and P uptake and may respond differently to inorganic nutrient and organic matter inputs. Our results highlight the need for a comprehensive assessment of N and P uptake and retention in Arctic streams in order to fully understand the impact of permafrost-derived materials on ecosystem processes, and their fate in continental drainage networks.

  15. Pressure driven currents near magnetic islands in 3D MHD equilibria: Effects of pressure variation within flux surfaces and of symmetry

    Science.gov (United States)

    Reiman, Allan H.

    2016-07-01

    ∇p are important in this region, and small non-MHD contributions to the parallel force balance equation cannot be neglected there. Two approaches are pursued to solve our equations for the pressure driven currents. First, the equilibrium equations are applied to an analytically tractable magnetic field with an island, obtaining explicit expressions for the rotational transform and magnetic coordinates, and for the pressure-driven current and its limiting behavior near the X-line. The second approach utilizes an expansion about the X-line to provide a more general calculation of the pressure-driven current near an X-line and of the rotational transform near a separatrix. The study presented in this paper is motivated, in part, by tokamak experiments with nonaxisymmetric magnetic perturbations, where significant differences are observed between the behavior of stellarator-symmetric and non-stellarator-symmetric configurations with regard to stabilization of edge localized modes by resonant magnetic perturbations. Implications for the coupling between neoclassical tearing modes, and for magnetic island stability calculations, are also discussed.

  16. The regulation of the chloroplast proton motive force plays a key role for photosynthesis in fluctuating light.

    Science.gov (United States)

    Armbruster, Ute; Correa Galvis, Viviana; Kunz, Hans-Henning; Strand, Deserah D

    2017-06-01

    Plants use sunlight as their primary energy source. During photosynthesis, absorbed light energy generates reducing power by driving electron transfer reactions. These are coupled to the transfer of protons into the thylakoid lumen, generating a proton motive force (pmf) required for ATP synthesis. Sudden alterations in light availability have to be met by regulatory mechanisms to avoid the over-accumulation of reactive intermediates and maximize energy efficiency. Here, the acidification of the lumen, as an intermediate product of photosynthesis, plays an important role by regulating photosynthesis in response to excitation energy levels. Recent findings reveal pmf regulation and the modulation of its composition as key determinants for efficient photosynthesis, plant growth, and survival in fluctuating light environments. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Motivational study for an hybrid demonstrator; Dossier de motivation pour un demonstrateur hybride

    Energy Technology Data Exchange (ETDEWEB)

    Boidron, M.; Fiorini, G.L.; Thomas, J.B. [CEA Cadarache, 13 - Saint Paul lez Durance (France). Direction des Reacteurs Nucleaires; Flocard, H. [Institut National de Physique Nucleaire et de Physique des Particules (CNRS/IN2P3), 75 - Paris (France)

    2001-02-15

    This document recalls first the role of hybrid accelerator driven systems (ADS) in the domain of transmutation of long-lived fission products and minor actinides. It presents the specific contribution of these systems in the management of radioactive wastes and their technical feasibility and safety aspects. Then, follows a motivational analysis for the construction of a demonstration facility with its specifications and R and D needs: feasibility, schedule, links with other ADS-related programs, cost, international cooperation, recommendations. (J.S.)

  18. End-of-Life Preferences: A Theory-Driven Inventory

    Science.gov (United States)

    Bonin-Scaon, Sylvie; Munoz Sastre, Maria Teresa; Chasseigne, Gerard; Sorum, Paul C.; Mullet, Etienne

    2009-01-01

    The study aimed at making a theory-driven inventory of end-of-life preferences. Participants were asked about a variety of preferences representing all eight motivational states described in Apter's Metamotivational Theory (AMT; Apter, 2001). Data from a convenience sample of 965 community participants and a convenience sample of 81 persons…

  19. Clinicians' ability, motivation, and opportunity to acquire and transfer knowledge: An age-driven perspective.

    Science.gov (United States)

    Profili, Silvia; Sammarra, Alessia; Dandi, Roberto; Mascia, Daniele

    2017-11-08

    Many countries are seeing a dramatic increase in the average age of their clinicians. The literature often highlights the challenges of high replacement costs and the need for strategies to retain older personnel. Less discussed are the potential pitfalls of knowledge acquisition and transfer that accompany this aging issue. We propose a conceptual framework for understanding how clinicians' age interact with ability, motivation, and opportunity to predict clinical knowledge transfer and acquisition in health care organizations. This study integrates life-span development perspectives with the ability-motivation-opportunity framework to develop a number of testable propositions on the interaction between age and clinicians' ability, motivation, and opportunity to acquire and transfer clinical knowledge. We posit that the interaction between ability (the knowledge and skills to acquire knowledge), motivation (the willingness to acquire and transfer knowledge), and opportunity (resources required for acquiring and transferring knowledge) is a determinant of successful knowledge management. We also suggest that clinicians' age-and more specifically, the cognitive and motivational changes that accompany aging-moderates these relationships. This study contributes to existing research by offering a set of testable propositions for future research. These propositions will hopefully encourage empirical research into this important topic and lead to guidelines for reducing the risks of organizational knowledge loss due to aging. We suggest several ways that health care organizations can tailor managerial practices in order to help capitalize on the knowledge-based resources held by their younger and older clinicians. Such initiatives may affect employees' ability (e.g., by providing specific training programs), motivation (e.g., by expanding subjective perceptions of future time at work), and opportunities (e.g., by providing mentoring, reverse mentoring, and coaching

  20. The Leadership Effect on Employees Motivation

    Institute of Scientific and Technical Information of China (English)

    Henrique Guilherme Scatolin; Rafael Barranco; Robson Pereira de Torres

    2014-01-01

    This paper discusses the effect that the leadership causes on employees' motivation within the organizations, in order to show the reader that leadership is an external stimulus necessary to awaken the employees' intrinsic feelings, among them, the motivation. The leader faces constant challenges in the organization day by day and he is responsible for understanding his lead team, as well as their several natures and cultural models. In the classical theory, people worked in a mechanistic manner with the motivation, but with the industrial development and the competitiveness incitement, it was observed that to survive on the market, companies need to extract as much as possible of the intellectual capital of its human factor. Therefore, it is necessary to establish conditions under which people feel motivated to work towards the goals outlined by the companies, thus obtaining satisfactory results. This article concludes that motivation is an internal force that is directly affected by external factors in which the manager is responsible for identifying what really motivates each employee in the search for the best results.

  1. How motivation and reward learning modulate selective attention.

    Science.gov (United States)

    Bourgeois, A; Chelazzi, L; Vuilleumier, P

    2016-01-01

    Motivational stimuli such as rewards elicit adaptive responses and influence various cognitive functions. Notably, increasing evidence suggests that stimuli with particular motivational values can strongly shape perception and attention. These effects resemble both selective top-down and stimulus-driven attentional orienting, as they depend on internal states but arise without conscious will, yet they seem to reflect attentional systems that are functionally and anatomically distinct from those classically associated with frontoparietal cortical networks in the brain. Recent research in human and nonhuman primates has begun to reveal how reward can bias attentional selection, and where within the cognitive system the signals providing attentional priority are generated. This review aims at describing the different mechanisms sustaining motivational attention, their impact on different behavioral tasks, and current knowledge concerning the neural networks governing the integration of motivational influences on attentional behavior. © 2016 Elsevier B.V. All rights reserved.

  2. Moods as ups and downs of the motivation pendulum: Revisiting Reinforcement Sensitivity Theory (RST in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Tal eGonen

    2014-11-01

    Full Text Available Motivation is a key neurobehavioral concept underlying adaptive responses to environmental incentives and threats. As such, dysregulation of motivational processes may be critical in the formation of abnormal behavioral patterns/tendencies. According to the long standing model of the Reinforcement Sensitivity Theory (RST, motivation behaviors are driven by three neurobehavioral systems mediating the sensitivity to punishment, reward or goal-conflict. Corresponding to current neurobehavioral theories in psychiatry, this theory links abnormal motivational drives to abnormal behavior; viewing depression and mania as two abnormal extremes of reward driven processes leading to either under or over approach tendencies, respectively. We revisit the RST framework in the context of bipolar disorder (BD and challenge this concept by suggesting that dysregulated interactions of both punishment and reward related processes better account for the psychological and neural abnormalities observed in BD. We further present an integrative model positing that the three parallel motivation systems currently proposed by the RST model, can be viewed as subsystems in a large-scale neurobehavioral network of motivational decision making.

  3. Women's preferences for contralateral prophylactic mastectomy: An investigation using protection motivation theory.

    Science.gov (United States)

    Tesson, Stephanie; Richards, Imogen; Porter, David; Phillips, Kelly-Anne; Rankin, Nicole; Musiello, Toni; Marven, Michelle; Butow, Phyllis

    2016-05-01

    Most women diagnosed with unilateral breast cancer without BRCA1 or BRCA2 mutations are at low risk of contralateral breast cancer. Contralateral Prophylactic Mastectomy (CPM) decreases the relative risk of contralateral breast cancer, but may not increase life expectancy; yet international uptake is increasing. This study applied protection motivation theory (PMT) to determine factors associated with women's intentions to undergo CPM. Three hundred eighty-eight women previously diagnosed with unilateral breast cancer and of negative or unknown BRCA1 or BRCA2 status were recruited from an advocacy group's research database. Participants completed measures of PMT constructs based on a common hypothetical CPM decision-making scenario. PMT constructs explained 16% of variance in intentions to undergo CPM. Response efficacy (CPM's advantages) and response costs (CPM's disadvantages) were unique individual predictors of intentions. Decision-making appears driven by considerations of the psychological, cosmetic and emotional advantages and disadvantages of CPM. Overestimations of threat to life from contralateral breast cancer and survival benefit from CPM also appear influential factors. Patients require balanced and medically accurate information regarding the pros and cons of CPM, survival rates, and recurrence risks to ensure realistic and informed decision-making.

  4. Understanding low uptake of mass treatment for intestinal schistosomiasis among school children

    DEFF Research Database (Denmark)

    Muhumuza, Simon; Olsen, Annette; Nuwaha, Fred

    2015-01-01

    among school children is low and to suggest strategies for improved uptake. This was a cross-sectional qualitative study in which 24 focus group discussions and 15 key informant interviews were conducted 2 months after MDA. The focus group discussions were held with school children in twelve primary...... schools and the key informant interviews were held with school teachers, sub-county health assistants and the District Vector Control Officer. The study shows that the low uptake of praziquantel among school children is a result of a complex interplay between individual, interpersonal, institutional......, yet many parents cannot meet the cost of a daily meal due to the prevailing poverty in the area. It is concluded that strategies to improve uptake of praziquantel among school children need to be multi-pronged addressing not only the preparation and motivation of teachers and health education...

  5. Motivations and barriers to uptake and use of female-initiated, biomedical HIV prevention products in sub-Saharan Africa: an adapted meta-ethnography.

    Science.gov (United States)

    Eakle, Robyn; Bourne, Adam; Jarrett, Caitlin; Stadler, Jonathan; Larson, Heidi

    2017-12-19

    Women bear a disproportionate burden of HIV throughout the world prompting extensive research into HIV prevention products for women which has met with varied success. With an aim of informing future policy and programming, this review examines the barriers and motivations to the uptake and use of female initiated products in sub-Saharan countries. We conducted a systematic review as an adapted meta-ethnography of qualitative data focused on actual use of products. After deduplication, 10,581 and 3861 papers in the first and second round respectively were screened. Following the PRISMA guidance, 22 papers were selected and synthesized using Malpass's definitions of first, second, and third order constructs. First order constructs, consisting of participant data published in the selected papers, were extracted and categorised by second and third order constructs for analysis. A weight of evidence review was conducted to compare and assess quality across the papers. The 22 papers selected span 11 studies in 13 countries. We derived 23 s order constructs that were translated into seven overarching third order constructs: Sexual Satisfaction, Trust, Empowerment and Control, Personal Well-being, Product use in the social-cultural environment, Practical Considerations, Risk Reduction, and Perceptions of Efficacy. Relationships and trust were seen to be as or more important for product use as efficacy. These constructs reveal an inherent inter-relationality where decision making around HIV prevention uptake and use cannot be binary or mono-faceted, but rather conducted on multiple levels. We developed a framework illustrating the central and proximal natures of constructs as they relate to the decision-making process surrounding the use of prevention products. Health systems, structural, and individual level HIV prevention interventions for women should adopt a holistic approach. Interventions should attend to the ways in which HIV prevention products can serve to reduce

  6. Urban IDPs and Poverty: Analysis of the Effect of Mass Forced Displacement on Urban Poverty in Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Nermin Oruc

    2015-06-01

    Full Text Available This paper analyzes the effect of mass forced displacement on urban poverty in Bosnia and Herzegovina. The process of displacement in Bosnia and Herzegovina involved “forced evictions”, implying no choice in displacement decision, meaning that this type of rural-urban migration was not a rational decision driven by economic motives. Consequently, this can possibly lead to a larger incidence of poverty among displaced people. The paper starts with a discussion of the specific features of the process of forced displacement and their possibly different effect on urban poverty compared to voluntary migration, based on qualitative evidence collected through interviews with people who experienced forced displacement during the conflict in the 1990s. Then, the probit model of determinants of poverty, based on the Living Standards Measurement Survey data, was estimated in order to provide empirical evidence of the effect of mass forced displacement on urban poverty, as well as the difference in the poverty incidence among displaced people compared to voluntary migrants. The results suggest that consumption is significantly lower among displaced households, while incidence of poverty is not affected by displacement status. The evidence also contributes to the migration literature by providing specific results about the relationship between mass forced displacement and urban poverty.

  7. BRIDGE21--Exploring the Potential to Foster Intrinsic Student Motivation through a Team-Based, Technology-Mediated Learning Model

    Science.gov (United States)

    Lawlor, John; Marshall, Kevin; Tangney, Brendan

    2016-01-01

    It is generally accepted that intrinsic student motivation is a critical requirement for effective learning but formal learning in school places a huge reliance on extrinsic motivation to focus the learner. This reliance on extrinsic motivation is driven by the pressure on formal schooling to "deliver to the test." The experience of the…

  8. Nuclear Material Detection by One-Short-Pulse-Laser-Driven Neutron Source

    International Nuclear Information System (INIS)

    Favalli, Andrea; Aymond, F.; Bridgewater, Jon S.; Croft, Stephen; Deppert, O.; Devlin, Matthew James; Falk, Katerina; Fernandez, Juan Carlos; Gautier, Donald Cort; Gonzales, Manuel A.; Goodsell, Alison Victoria; Guler, Nevzat; Hamilton, Christopher Eric; Hegelich, Bjorn Manuel; Henzlova, Daniela; Ianakiev, Kiril Dimitrov; Iliev, Metodi; Johnson, Randall Philip; Jung, Daniel; Kleinschmidt, Annika; Koehler, Katrina Elizabeth; Pomerantz, Ishay; Roth, Markus; Santi, Peter Angelo; Shimada, Tsutomu; Swinhoe, Martyn Thomas; Taddeucci, Terry Nicholas; Wurden, Glen Anthony; Palaniyappan, Sasikumar; McCary, E.

    2015-01-01

    Covered in the PowerPoint presentation are the following areas: Motivation and requirements for active interrogation of nuclear material; laser-driven neutron source; neutron diagnostics; active interrogation of nuclear material; and, conclusions, remarks, and future works.

  9. Compressible fluid flows driven by stochastic forcing

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Maslowski, B.; Novotný, A.

    2013-01-01

    Roč. 254, č. 3 (2013), s. 1342-1358 ISSN 0022-0396 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Institutional support: RVO:67985840 Keywords : stochastic Navier-Stokes equations * compressible fluid * random driving force Subject RIV: BA - General Mathematics Impact factor: 1.570, year: 2013 http://www.sciencedirect.com/science/article/pii/S0022039612004135

  10. Organizational Communication: Communication and Motivation in The Workplace

    Directory of Open Access Journals (Sweden)

    Sari Ramadanty

    2016-01-01

    Full Text Available Every human activity was basically driven by the motivation. Work motivation was a condition or an energy that directed employees to achieve organizational goals of the company. Nowadays, the development of organizational communication saw the communication as one of the most dominant and important activity in the organization and it could be able to motivate employees. The purpose of this study was to reveal how the role of the communication that occurs within the organization could give the motivation to employee. The problem of the research was the relationship employee motivation with factors of communication, such as nonverbal communication, interpersonal communication leadership and communication climate. The method used descriptive qualitative method. Methods of data collection of this study were literature study. Research finds that nonverbal communication, interpersonal communication leadership and communication climate have a significant role to form employee motivation. Nonverbal communication has slightly strong role in shaping the positive motivation to employee. The role includes body communication, facial communication and eye communication. Interpersonal communication leader is based on the satisfaction level of information between management and employees. Management and transparency in openness in downward communication under the form of information from superiors are by listening the communication between supervisors and employees are running smoothly. 

  11. Water-driven micromotors.

    Science.gov (United States)

    Gao, Wei; Pei, Allen; Wang, Joseph

    2012-09-25

    We demonstrate the first example of a water-driven bubble-propelled micromotor that eliminates the requirement for the common hydrogen peroxide fuel. The new water-driven Janus micromotor is composed of a partially coated Al-Ga binary alloy microsphere prepared via microcontact mixing of aluminum microparticles and liquid gallium. The ejection of hydrogen bubbles from the exposed Al-Ga alloy hemisphere side, upon its contact with water, provides a powerful directional propulsion thrust. Such spontaneous generation of hydrogen bubbles reflects the rapid reaction between the aluminum alloy and water. The resulting water-driven spherical motors can move at remarkable speeds of 3 mm s(-1) (i.e., 150 body length s(-1)), while exerting large forces exceeding 500 pN. Factors influencing the efficiency of the aluminum-water reaction and the resulting propulsion behavior and motor lifetime, including the ionic strength and environmental pH, are investigated. The resulting water-propelled Al-Ga/Ti motors move efficiently in different biological media (e.g., human serum) and hold considerable promise for diverse biomedical or industrial applications.

  12. ENTREPRENEURIAL MOTIVATIONS: ARE WOMEN DRIVEN BY DIFFERENT MOTIVATORS THAN MEN? (II SOME EVIDENCE FOR EU AND ROMANIA

    Directory of Open Access Journals (Sweden)

    Alina Badulescu

    2010-12-01

    Full Text Available The present article has the goal to reveal the (eventually differences between entrepreneurial motivations between men and women, in the case of EU and Romania. In the first part, we make a brief research into the literature related to this subject, and in the second part we shall reveal the facts and figures in the EU and Romania.

  13. Dynamic signatures of driven vortex motion.

    Energy Technology Data Exchange (ETDEWEB)

    Crabtree, G. W.; Kwok, W. K.; Lopez, D.; Olsson, R. J.; Paulius, L. M.; Petrean, A. M.; Safar, H.

    1999-09-16

    We probe the dynamic nature of driven vortex motion in superconductors with a new type of transport experiment. An inhomogeneous Lorentz driving force is applied to the sample, inducing vortex velocity gradients that distinguish the hydrodynamic motion of the vortex liquid from the elastic and-plastic motion of the vortex solid. We observe elastic depinning of the vortex lattice at the critical current, and shear induced plastic slip of the lattice at high Lorentz force gradients.

  14. Caring Cooperators and Powerful Punishers: Differential Effects of Induced Care and Power Motivation on Different Types of Economic Decision Making.

    Science.gov (United States)

    Chierchia, G; Lesemann, F H Parianen; Snower, D; Vogel, M; Singer, T

    2017-09-11

    Standard economic theory postulates that decisions are driven by stable context-insensitive preferences, while motivation psychology suggests they are driven by distinct context-sensitive motives with distinct evolutionary goals and characteristic psycho-physiological and behavioral patterns. To link these fields and test how distinct motives could differentially predict different types of economic decisions, we experimentally induced participants with either a Care or a Power motive, before having them take part in a suite of classic game theoretical paradigms involving monetary exchange. We show that the Care induction alone raised scores on a latent factor of cooperation-related behaviors, relative to a control condition, while, relative to Care, Power raised scores on a punishment-related factor. These findings argue against context-insensitive stable preferences and theories of strong reciprocity and in favor of a motive-based approach to economic decision making: Care and Power motivation have a dissociable fingerprint in shaping either cooperative or punishment behaviors.

  15. The cyto- and genotoxicity of organotin compounds is dependent on the cellular uptake capability

    International Nuclear Information System (INIS)

    Dopp, E.; Hartmann, L.M.; Recklinghausen, U. von; Florea, A.M.; Rabieh, S.; Shokouhi, B.; Hirner, A.V.; Obe, G.; Rettenmeier, A.W.

    2007-01-01

    Organotin compounds have been widely used as stabilizers and anti-fouling agents with the result that they are ubiquitously distributed in the environment. Organotins accumulate in the food chain and potential effects on human health are disquieting. It is not known as yet whether cell surface adsorption or accumulation within the cell, or indeed both is a prerequisite for the toxicity of organotin compounds. In this study, the alkylated tin derivatives monomethyltin trichloride (MMT), dimethyltin dichloride (DMT), trimethyltin chloride (TMT) and tetramethyltin (TetraMT) were investigated for cyto- and genotoxic effects in CHO-9 cells in relation to the cellular uptake. To identify genotoxic effects, induction of micronuclei (MN), chromosome aberrations (CA) and sister chromatid exchanges (SCE) were analyzed and the nuclear division index (NDI) was calculated. The cellular uptake was assessed using ICP-MS analysis. The toxicity of the tin compounds was also evaluated after forced uptake by electroporation. Our results show that uptake of the organotin compounds was generally low but dose-dependent. Only weak genotoxic effects were observed after exposure of cells to DMT and TMT. MMT and TetraMT were negative in the test systems. After forced uptake by electroporation MMT, DMT and TMT induced significant DNA damage at non-cytotoxic concentrations. The results presented here indicate a considerable toxicological potential of some organotin species but demonstrate clearly that the toxicity is modulated by the cellular uptake capability

  16. Macropinocytosis is responsible for the uptake of pathogenic and non-pathogenic mycobacteria by B lymphocytes (Raji cells

    Directory of Open Access Journals (Sweden)

    García-Pérez Blanca Estela

    2012-10-01

    Full Text Available Abstract Background The classical roles of B cells include the production of antibodies and cytokines and the generation of immunological memory, these being key factors in the adaptive immune response. However, their role in innate immunity is currently being recognised. Traditionally, B cells have been considered non-phagocytic cells; therefore, the uptake of bacteria by B cells is not extensively documented. In this study, we analysed some of the features of non-specific bacterial uptake by B lymphocytes from the Raji cell line. In our model, B cells were infected with Mycobacterium tuberculosis (MTB, Mycobacterium smegmatis (MSM, and Salmonella typhimurium (ST. Results Our observations revealed that the Raji B cells were readily infected by the three bacteria that were studied. All of the infections induced changes in the cellular membrane during bacterial internalisation. M. smegmatis and S. typhimurium were able to induce important membrane changes that were characterised by abundant filopodia and lamellipodia formation. These membrane changes were driven by actin cytoskeletal rearrangements. The intracellular growth of these bacteria was also controlled by B cells. M. tuberculosis infection also induced actin rearrangement-driven membrane changes; however, the B cells were not able to control this infection. The phorbol 12-myristate 13-acetate (PMA treatment of B cells induced filopodia and lamellipodia formation, the production of spacious vacuoles (macropinosomes, and the fluid-phase uptake that is characteristic of macropinocytosis. S. typhimurium infection induced the highest fluid-phase uptake, although both mycobacteria also induced fluid uptake. A macropinocytosis inhibitor such as amiloride was used and abolished the bacterial uptake and the fluid-phase uptake that is triggered during the bacterial infection. Conclusions Raji B cells can internalise S. typhimurium and mycobacteria through an active process, such as

  17. Benefits of an Air Force Contracting Warrant Officer Program

    Science.gov (United States)

    2011-12-01

    M., & Berry, J. W. (2011). The necessity of others is the mother of invention: instrinsic and prosocial motivations , perspective taking, and...Capital, Organizational Behavioral Assessment, Implementation Plan, Air Force 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified...10 3. Motivation

  18. Linear or Rotary Actuator Using Electromagnetic Driven Hammer as Prime Mover

    Science.gov (United States)

    Paine, Jeffrey S. N. (Inventor); Smith, Byron F. (Inventor); Sesler, Joshua J. (Inventor); Paine, Matthew T. (Inventor); McMahan, Bert K. (Inventor); McMahan, Mark C. (Inventor)

    2018-01-01

    We claim a hammer driven actuator that uses the fast-motion, low-force characteristics of an electro-magnetic or similar prime mover to develop kinetic energy that can be transformed via a friction interface to produce a higher-force, lower-speed linear or rotary actuator by using a hammering process to produce a series of individual steps. Such a system can be implemented using a voice-coil, electro-mechanical solenoid or similar prime mover. Where a typical actuator provides limited range of motion or low force, the range of motion of a linear or rotary impact driven motor can be configured to provide large displacements which are not limited by the characteristic dimensions of the prime mover.

  19. Professional Motivation Formation of Future Specialists under the Conditions of Regional Educational Complex

    Science.gov (United States)

    Kargina, Elena Mikhaylovna

    2015-01-01

    Motivation plays the leading role in the organization of the personality structure. It is a driving force of the activity. Motivation accounts for the behavior and activity and has a great impact on professional self-determination and person's satisfaction with the work. The problem of professional motivation formation of a future specialist is…

  20. Stability aspects of plasmas penetrated by neutral gas with respect to velocity driven modes

    International Nuclear Information System (INIS)

    Ohlsson, D.

    1978-08-01

    A study of the stability properties of dense partially ionized plasmas immersed in strong magnetic fields with respect to velocity driven modes are presented. First we consider modes driven by mass motion perpendicular to the lines of force and the unperturbed density and temperature gradients. The presence of a third fluid, neutral gas, gives under certain conditions rise to unstable modes. This type of instability arises independently or whether the applied electric field transverse to the lines of force, driving the mass motion, being parallel or antiparallel to the unperturbed density and temperature gradient. The presence of neutral gas also corresponds to stabilizing effects which, in certain parameter regions, result in a quenching of this instability. It is shown that modes driven by velocity shear perpendicular to the lines of force are effectively stabilized by viscous and resistive effects. These effects are in certain parameter ranges strongly enhanced on account of plasma-neutral gas interaction effects. In collisionless plasmas, modes driven by velocity shear parallel to the lines of force are stabilized by compressibility effects parallel to the magnetic field and by finite Larmor radius effects. (author)

  1. Chaos as an intermittently forced linear system.

    Science.gov (United States)

    Brunton, Steven L; Brunton, Bingni W; Proctor, Joshua L; Kaiser, Eurika; Kutz, J Nathan

    2017-05-30

    Understanding the interplay of order and disorder in chaos is a central challenge in modern quantitative science. Approximate linear representations of nonlinear dynamics have long been sought, driving considerable interest in Koopman theory. We present a universal, data-driven decomposition of chaos as an intermittently forced linear system. This work combines delay embedding and Koopman theory to decompose chaotic dynamics into a linear model in the leading delay coordinates with forcing by low-energy delay coordinates; this is called the Hankel alternative view of Koopman (HAVOK) analysis. This analysis is applied to the Lorenz system and real-world examples including Earth's magnetic field reversal and measles outbreaks. In each case, forcing statistics are non-Gaussian, with long tails corresponding to rare intermittent forcing that precedes switching and bursting phenomena. The forcing activity demarcates coherent phase space regions where the dynamics are approximately linear from those that are strongly nonlinear.The huge amount of data generated in fields like neuroscience or finance calls for effective strategies that mine data to reveal underlying dynamics. Here Brunton et al.develop a data-driven technique to analyze chaotic systems and predict their dynamics in terms of a forced linear model.

  2. Hybrid Force Control Based on ICMAC for an Astronaut Rehabilitative Training Robot

    OpenAIRE

    Lixun Zhang; Yupeng Zou; Lan Wang; Xinping Pei

    2012-01-01

    A novel Astronaut Rehabilitative Training Robot (ART) based on a cable‐driven mechanism is represented in this paper. ART, a typical passive force servo system, can help astronauts to bench press in a microgravity environment. The purpose of this paper is to design controllers to eliminate the surplus force caused by an astronaut’s active movements. Based on the dynamics modelling of the cable‐driven unit, a hybrid force controller based on improved credit assignment CMAC (ICMAC) is presented...

  3. Six axis force feedback input device

    Science.gov (United States)

    Ohm, Timothy (Inventor)

    1998-01-01

    The present invention is a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device's control of the slave robot to be within imaginary predetermined boundaries.

  4. On the application of motivation theory to human factors/ergonomics: motivational design principles for human-technology interaction.

    Science.gov (United States)

    Szalma, James L

    2014-12-01

    Motivation is a driving force in human-technology interaction. This paper represents an effort to (a) describe a theoretical model of motivation in human technology interaction, (b) provide design principles and guidelines based on this theory, and (c) describe a sequence of steps for the. evaluation of motivational factors in human-technology interaction. Motivation theory has been relatively neglected in human factors/ergonomics (HF/E). In both research and practice, the (implicit) assumption has been that the operator is already motivated or that motivation is an organizational concern and beyond the purview of HF/E. However, technology can induce task-related boredom (e.g., automation) that can be stressful and also increase system vulnerability to performance failures. A theoretical model of motivation in human-technology interaction is proposed, based on extension of the self-determination theory of motivation to HF/E. This model provides the basis for both future research and for development of practical recommendations for design. General principles and guidelines for motivational design are described as well as a sequence of steps for the design process. Human motivation is an important concern for HF/E research and practice. Procedures in the design of both simple and complex technologies can, and should, include the evaluation of motivational characteristics of the task, interface, or system. In addition, researchers should investigate these factors in specific human-technology domains. The theory, principles, and guidelines described here can be incorporated into existing techniques for task analysis and for interface and system design.

  5. Molecular dynamics for irradiation driven chemistry

    DEFF Research Database (Denmark)

    Sushko, Gennady B.; Solov'yov, Ilia A.; Solov'yov, Andrey V.

    2016-01-01

    A new molecular dynamics (MD) approach for computer simulations of irradiation driven chemical transformations of complex molecular systems is suggested. The approach is based on the fact that irradiation induced quantum transformations can often be treated as random, fast and local processes...... that describe the classical MD of complex molecular systems under irradiation. The proposed irradiation driven molecular dynamics (IDMD) methodology is designed for the molecular level description of the irradiation driven chemistry. The IDMD approach is implemented into the MBN Explorer software package...... involving small molecules or molecular fragments. We advocate that the quantum transformations, such as molecular bond breaks, creation and annihilation of dangling bonds, electronic charge redistributions, changes in molecular topologies, etc., could be incorporated locally into the molecular force fields...

  6. Mobile phone usage of young adults: The impact of motivational factors.

    CSIR Research Space (South Africa)

    Van Biljon, J

    2008-12-01

    Full Text Available This paper concerns the impact of motivational factors on mobile phone use profiles and the influence thereof on the design of mobile phones. It aims to provide an alternative to the current feature driven design perspectives...

  7. The moderating role of age in the relationship between volunteering motives and well-being.

    Science.gov (United States)

    Ho, Yuen Wan; You, Jin; Fung, Helene H

    2012-12-01

    Driven by socioemotional selectivity theory, this study examined whether age moderated the associations of volunteering motives with physical and psychological well-being in a sample of Hong Kong Chinese volunteers. Volunteering motives were measured by the volunteer functions inventory. Findings revealed that even after controlling for demographic characteristics and volunteering experience, age was related to higher social and value motives but lower career motives, and moderated the associations of social and protective motives with well-being. The associations of social motives with physical well-being were positive among older volunteers, but were negative among younger- and middle-aged volunteers. While protective motives were positively related to psychological well-being among all the volunteers, such effects were stronger among younger- and middle-aged volunteers than among older volunteers. Findings highlight the role of age in determining the relationship between volunteering motives and well-being.

  8. Antireward, compulsivity, and addiction: seminal contributions of Dr. Athina Markou to motivational dysregulation in addiction.

    Science.gov (United States)

    Koob, George F

    2017-05-01

    Addiction is defined as a chronically relapsing disorder characterized by compulsive drug seeking that is hypothesized to derive from multiple sources of motivational dysregulation. Dr. Athina Markou made seminal contributions to our understanding of the neurobiology of addiction with her studies on the dysregulation of reward function using animal models with construct validity. Repeated overstimulation of the reward systems with drugs of abuse decreases reward function, characterized by brain stimulation reward and presumbably reflecting dysphoria-like states. The construct of negative reinforcement, defined as drug taking that alleviates a negative emotional state that is created by drug abstinence, is particularly relevant as a driving force in both the withdrawal/negative affect and preoccupation/anticipation stages of the addiction cycle. The negative emotional state that drives such negative reinforcement is hypothesized to derive from the dysregulation of key neurochemical circuits that drive incentive-salience/reward systems (dopamine, opioid peptides) in the ventral striatum and from the recruitment of brain stress systems (corticotropin-releasing factor, dynorphin) within the extended amygdala. As drug taking becomes compulsive-like, the factors that motivate behavior are hypothesized to shift to drug-seeking behavior that is driven not only by positive reinforcement but also by negative reinforcement. This shift in motivation is hypothesized to reflect the allostatic misregulation of hedonic tone such that drug taking makes the hedonic negative emotional state worse during the process of seeking temporary relief with compulsive drug taking.

  9. Ideology, motivated reasoning, and cognitive reflection

    Directory of Open Access Journals (Sweden)

    Dan M. Kahan

    2013-07-01

    Full Text Available Decision scientists have identified various plausible sources of ideological polarization over climate change, gun violence, national security, and like issues that turn on empirical evidence. This paper describes a study of three of them: the predominance of heuristic-driven information processing by members of the public; ideologically motivated reasoning; and the cognitive-style correlates of political conservativism. The study generated both observational and experimental data inconsistent with the hypothesis that political conservatism is distinctively associated with either unreflective thinking or motivated reasoning. Conservatives did no better or worse than liberals on the Cognitive Reflection Test (Frederick, 2005, an objective measure of information-processing dispositions associated with cognitive biases. In addition, the study found that ideologically motivated reasoning is not a consequence of over-reliance on heuristic or intuitive forms of reasoning generally. On the contrary, subjects who scored highest in cognitive reflection were the most likely to display ideologically motivated cognition. These findings corroborated an alternative hypothesis, which identifies ideologically motivated cognition as a form of information processing that promotes individuals' interests in forming and maintaining beliefs that signify their loyalty to important affinity groups. The paper discusses the practical significance of these findings, including the need to develop science communication strategies that shield policy-relevant facts from the influences that turn them into divisive symbols of political identity.

  10. Nutrient Uptake and Metabolism Along a Large Scale Tropical Physical-Chemical Gradient

    Science.gov (United States)

    Tromboni, F.; Neres-Lima, V.; Saltarelli, W. A.; Miwa, A. C. P.; Cunha, D. G. F.

    2016-12-01

    Nutrient spiraling is a whole-system approach for estimating nutrient uptake that can be used to assess aquatic ecosystems' responses to environmental change and anthropogenic impacts. Historically research on nutrient dynamic uptake in streams has focused on single nutrient dynamics and only rarely the stoichiometric uptake has been considered and linked to carbon metabolism driven by autotrophic and heterotrophic production. We investigated the relationship between uptake of phosphate (PO43-), nitrate (NO3-) ammonium (NH4+) and total dissolve nitrogen (DIN)/ PO43-; and gross primary production (GPP), respiration (R), and net ecosystem productivity (NEP) in six relatively pristine streams with differences regarding canopy cover and physical characteristics, located in a large scale gradient from tropical Atlantic Forest to an Atlantic forest/Cerrado (Brazilian Savanna) transition. We carried out whole stream instantaneous additions of PO43-, NO3- and NH4+ added to each stream in combination, using the TASCC (Tracer Additions for Spiraling Curve Characterization) method. Metabolism measurements were performed in the same streams right after uptake was measured, using one-station open channel method and re-aeration estimations for those sites. We found different background concentrations in the streams located in the Atlantic forest compared with the transition area with Cerrado. In general PO43- and NO3- uptake increased with the decreasing of canopy cover, while a positive relation with background concentration better explained NH4+uptake. DIN/PO43- uptake increased with increasing R and NEP. Little work on functional characteristics of pristine streams has been conducted in this region and this work provides an initial characterization on nitrogen and phosphorus dynamics as well as their stoichiometric uptake in streams.

  11. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine inhibits proton motive force in energized liver mitochondria

    International Nuclear Information System (INIS)

    Singh, Y.; Bhatnagar, R.; Sidhu, G.S.; Batra, J.K.; Krishna, G.

    1989-01-01

    It is known that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which induces Parkinson's-like disease in primates and humans, depletes hepatocytes of ATP and subsequently causes cell death. Incubation of rat liver mitochondria with MPTP and 1-methyl-4-phenyl pyridinium ion (MPP+) significantly inhibited incorporation of 32 Pi into ATP. MPTP and MPP+ inhibited the development of membrane potential and pH gradient in energized rat liver mitochondria, suggesting that reduction of the proton motive force may have reduced ATP synthesis. Since deprenyl, an inhibitor of monoamine oxidase, prevented the formation of MPP+ and inhibited the decrease in membrane potential caused by MPTP, but not that caused by MPP+, these effects of MPTP, as well as cell death, probably were mediated by MPP+. This mechanism may play a role in the specific loss of dopaminergic neurons resulting in MPTP-induced Parkinson's disease

  12. The role of organizational culture in motivating innovative behaviour in construction firms

    NARCIS (Netherlands)

    Hartmann, Andreas

    2006-01-01

    Motivation is the main force through which individuals allocate effort to generate and implement innovative ideas. However, employees are only motivated to go beyond their designated role and get involved in spontaneous and innovative activities if they have a strong identification with the

  13. MOTIVATIONAL AND VALUE-SEMANTIC DETERMINANTS OF INDIVIDUAL ASSERTIVENESS

    Directory of Open Access Journals (Sweden)

    Lebedeva Inga Viktorovna

    2013-04-01

    Full Text Available The paper attempts to reveal the concept of "determinants of assertiveness" of a personality, which are determined by motivational characteristics and life value and meaning orientations of the individual. The immediate driving force of human action is the motive or the system of motives. The system of motives of human behavior in different situations of activities, communication and cognition is determined by the personal world view (set of ideas, interests, and beliefs. The value orientation, influencing the direction of human activity, determines a person's behavior and is a personality determinant in the manifestations of assertive behavior and assertiveness. Therefore, the significant psychological factors that contribute to the development of assertiveness are high motivation to success, positive attitudes, and such values as compassion, tolerance, mutual understanding, sympathy, concern that oppose to violence, domination, suppression and submission. The article also presents the results of an empirical study of motivational and value-semantic characteristics of the individual.

  14. Light-driven robotics for nanoscopy

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    2013-01-01

    The science fiction inspired shrinking of macro-scale robotic manipulation and handling down to the micro- and nanoscale regime opens new doors for exploiting the forces and torques of light for micro- and nanoscopic probing, actuation and control. Advancing light-driven micro-robotics requires...... and matter for robotically probing at the smallest biological length scales....

  15. The relationship between transpiration and nutrient uptake in wheat changes under elevated atmospheric CO2.

    Science.gov (United States)

    Houshmandfar, Alireza; Fitzgerald, Glenn J; O'Leary, Garry; Tausz-Posch, Sabine; Fletcher, Andrew; Tausz, Michael

    2017-12-04

    The impact of elevated [CO 2 ] (e[CO 2 ]) on crops often includes a decrease in their nutrient concentrations where reduced transpiration-driven mass flow of nutrients has been suggested to play a role. We used two independent approaches, a free-air CO 2 enrichment (FACE) experiment in the South Eastern wheat belt of Australia and a simulation study employing the agricultural production systems simulator (APSIM), to show that transpiration (mm) and nutrient uptake (g m -2 ) of nitrogen (N), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg) and manganese (Mn) in wheat are correlated under e[CO 2 ], but that nutrient uptake per unit water transpired is higher under e[CO 2 ] than under ambient [CO 2 ] (a[CO 2 ]). This result suggests that transpiration-driven mass flow of nutrients contributes to decreases in nutrient concentrations under e[CO 2 ], but cannot solely explain the overall decline. © 2017 Scandinavian Plant Physiology Society.

  16. Radiation-driven winds in x-ray binaries

    International Nuclear Information System (INIS)

    Friend, D.B.; Castor, J.I.

    1982-01-01

    We discuss the properties of a radiation-driven stellar wind in an X-ray binary system. The Castor, Abbott, Klein line-driven wind model is used, but the effects of the compact companion (gravity and continuum radiation pressure) and the centrifugal force due to orbital motion are included. These forces destroy the spherical symmetry of the wind and can make the mass loss and accretion strong functions of the size of the primary relative to its critical potential lobe. We in most systems the wind alone could power the X-ray emission. It also appears that, in the evolution of these systems, there would be a continuous transition from wind accretion to critical potential lobe overflow. The model is also used to make a prediction about the nature of a suspected binary system which is not known to be an X-ray emitter

  17. On Motivation and Motivation

    OpenAIRE

    Mircea UDRESCU

    2014-01-01

    Economic motivations were a big influence on consumer behavior motivation. In this context, it is considered that the general motives which give motivation to purchase content can be structured into rational and emotional motives, the motives innate and acquired motives, all gaining an individual or group event. The study of consumer behavior, with general motivations, attention increasingly larger granted special incentives, consisting of assertiveness feeling (emerging desire for a product)...

  18. Dynamic posturography using a new movable multidirectional platform driven by gravity.

    NARCIS (Netherlands)

    Commissaris, D.A.C.M.; Nieuwenhuijzen, P.H.J.A.; Overeem, S.; Vos, A. de; Duysens, J.E.J.; Bloem, B.R.

    2002-01-01

    Human upright balance control can be quantified using movable platforms driven by servo-controlled torque motors (dynamic posturography). We introduce a new movable platform driven by the force of gravity acting upon the platform and the subject standing on it. The platform consists of a 1 m2 metal

  19. Dynamic posturography using a new movable multidirectional platform driven by gravity

    NARCIS (Netherlands)

    Commissaris, D.A.C.M.; Nieuwenhuijzen, P.H.J.A.; Overeem, S.; Vos, A. de; Duysens, J.E.J.; Bloem, B.R.

    2002-01-01

    Human upright balance control can be quantified using movable platforms driven by servo-controlled torque motors (dynamic posturography). We introduce a new movable platform driven by the force of gravity acting upon the platform and the subject standing on it. The platform consists of a 1 m(2)

  20. Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

    International Nuclear Information System (INIS)

    Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

    2005-01-01

    In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. The motivational force for tritium decontamination by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

  1. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: a multi model linear feedback analysis

    International Nuclear Information System (INIS)

    Roy, Tilla; Bopp, Laurent; Gehlen, Marion; Cadule, Patricia; Schneider, Birgit; Frolicher, Thomas L.; Segschneider, Joachim; Tjiputra, Jerry; Heinze, Christoph; Joos, Fortunat

    2011-01-01

    The increase in atmospheric CO 2 over this century depends on the evolution of the oceanic air-sea CO 2 uptake, which will be driven by the combined response to rising atmospheric CO 2 itself and climate change. Here, the future oceanic CO 2 uptake is simulated using an ensemble of coupled climate-carbon cycle models. The models are driven by CO 2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high-emission scenario. A linear feedback analysis successfully separates the regional future (2010-2100) oceanic CO 2 uptake into a CO 2 -induced component, due to rising atmospheric CO 2 concentrations, and a climate-induced component, due to global warming. The models capture the observation based magnitude and distribution of anthropogenic CO 2 uptake. The distributions of the climate-induced component are broadly consistent between the models, with reduced CO 2 uptake in the sub polar Southern Ocean and the equatorial regions, owing to decreased CO 2 solubility; and reduced CO 2 uptake in the mid-latitudes, owing to decreased CO 2 solubility and increased vertical stratification. The magnitude of the climate-induced component is sensitive to local warming in the southern extra-tropics, to large freshwater fluxes in the extra-tropical North Atlantic Ocean, and to small changes in the CO 2 solubility in the equatorial regions. In key anthropogenic CO 2 uptake regions, the climate-induced component offsets the CO 2 - induced component at a constant proportion up until the end of this century. This amounts to approximately 50% in the northern extra-tropics and 25% in the southern extra-tropics and equatorial regions. Consequently, the detection of climate change impacts on anthropogenic CO 2 uptake may be difficult without monitoring additional tracers, such as oxygen. (authors)

  2. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: a multi model linear feedback analysis

    International Nuclear Information System (INIS)

    Roy, Tilla; Bopp, Laurent; Gehlen, Marion; Cadule, Patricia

    2011-01-01

    The increase in atmospheric CO 2 over this century depends on the evolution of the oceanic air-sea CO 2 uptake, which will be driven by the combined response to rising atmospheric CO 2 itself and climate change. Here, the future oceanic CO 2 uptake is simulated using an ensemble of coupled climate-carbon cycle models. The models are driven by CO 2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high-emission scenario. A linear feedback analysis successfully separates the regional future (2010-2100) oceanic CO 2 uptake into a CO 2 -induced component, due to rising atmospheric CO 2 concentrations, and a climate-induced component, due to global warming. The models capture the observation based magnitude and distribution of anthropogenic CO 2 uptake. The distributions of the climate-induced component are broadly consistent between the models, with reduced CO 2 uptake in the sub-polar Southern Ocean and the equatorial regions, owing to decreased CO 2 solubility; and reduced CO 2 uptake in the mid latitudes, owing to decreased CO 2 solubility and increased vertical stratification. The magnitude of the climate-induced component is sensitive to local warming in the southern extra tropics, to large freshwater fluxes in the extra tropical North Atlantic Ocean, and to small changes in the CO 2 solubility in the equatorial regions. In key anthropogenic CO 2 uptake regions, the climate-induced component offsets the CO 2 - induced component at a constant proportion up until the end of this century. This amounts to approximately 50% in the northern extra tropics and 25% in the southern extra tropics and equatorial regions. Consequently, the detection of climate change impacts on anthropogenic CO 2 uptake may be difficult without monitoring additional tracers, such as oxygen. (authors)

  3. Motivations Behind Sustainable Purchasing

    OpenAIRE

    Vörösmarty, Gyöngyi; Dobos, Imre; Tátrai, Tünde

    2011-01-01

    Sustainability issues in purchasing are receiving greater attention. Literature is rapidly growing, with several research programs being initiated to investigate the topic. This study presents the results of a research project which aims to reveal and structure the motivating forces leading companies to make efforts in sustainability purchasing and the means used to attain achievements in some fields of sustainability. Results presented in the literature are scattered in terms of ...

  4. Motivating and demotivating forces in teams: cross-level influences of empowering leadership and relationship conflict.

    Science.gov (United States)

    Chen, Gilad; Sharma, Payal Nangia; Edinger, Suzanne K; Shapiro, Debra L; Farh, Jiing-Lih

    2011-05-01

    Using cross-cultural laboratory and field studies with samples of leaders, employees, and students from the United States and the People's Republic of China, we examined how team-level stimuli, including empowering leadership and relationship conflict, combine to influence individual members' motivational states of psychological empowerment and affective commitment. As predicted, we found that these motivational states are individually and jointly influenced by teams' level of empowering leadership and relationship conflict and that these motivational states mediate the relationships between team stimuli and team members' innovative and teamwork behaviors and turnover intentions. In addition, results held despite controlling for team members' nationality and collectivism. We discuss contributions of our study to the team motivation, conflict, and stress literatures.

  5. Novelty-driven Particle Swarm Optimization

    DEFF Research Database (Denmark)

    Galvao, Diana; Lehman, Joel Anthony; Urbano, Paulo

    2015-01-01

    Particle Swarm Optimization (PSO) is a well-known population-based optimization algorithm. Most often it is applied to optimize objective-based fitness functions that reward progress towards a desired objective or behavior. As a result, search increasingly focuses on higher-fitness areas. However......, in problems with many local optima, such focus often leads to premature convergence that precludes reaching the intended objective. To remedy this problem in certain types of domains, this paper introduces Novelty-driven Particle Swarm Optimization (NdPSO), which is motivated by the novelty search algorithm...

  6. Multi-Model Assessment of Trends and Variability in Terrestrial Carbon Uptake in India

    Science.gov (United States)

    Rao, A. S.; Bala, G.; Ravindranath, N. H.

    2015-12-01

    Indian terrestrial ecosystem exhibits large temporal and spatial variability in carbon sources and sinks due to its monsoon based climate system, diverse land use and land cover distribution and cultural practices. In this study, a multi-model based assessment is made to study the trends and variability in the land carbon uptake for India over the 20th century. Data from nine models which are a part of a recent land surface model intercomparison project called TRENDY is used for the study. These models are driven with common forcing data over the period of 1901-2010. Model output variables assessed include: gross primary production (GPP), heterotrophic respiration (Rh), autotrophic respiration (Ra) and net primary production (NPP). The net ecosystem productivity (NEP) for the Indian region was calculated as a difference of NPP and Rh and it was found that NEP for the region indicates an estimated increase in uptake over the century by -0.6 TgC/year per year. NPP for India also shows an increasing trend of 2.03% per decade from 1901-2010. Seasonal variation in the multimodel mean NPP is maximum during the southwest monsoon period (JJA) followed by the post monsoon period (SON) and is attributed to the maximum in rainfall for the region during the months of JJA. To attribute the changes seen in the land carbon variables, influence of climatic drivers such as precipitation, temperature and remote influences of large scale phenomenon such as ENSO on the land carbon of the region are also estimated in the study. It is found that although changes in precipitation shows a good correlation to the changes seen in NEP, remote drivers like ENSO do not have much effect on them. The Net Ecosystem Exchange is calculated with the inclusion of the land use change flux and fire flux from the models. NEE suggests that the region behaves as a small sink for carbon with an net uptake of 5 GtC over the past hundred years.

  7. Forces on particles in microstreaming flows

    Science.gov (United States)

    Hilgenfeldt, Sascha; Rallabandi, Bhargav; Thameem, Raqeeb

    2015-11-01

    In various microfluidic applications, vortical steady streaming from ultrasonically driven microbubbles is used in concert with a pressure-driven channel flow to manipulate objects. While a quantitative theory of this boundary-induced streaming is available, little work has been devoted to a fundamental understanding of the forces exerted on microparticles in boundary streaming flows, even though the differential action of such forces is central to applications like size-sensitive sorting. Contrary to other microfluidic sorting devices, the forces in bubble microstreaming act over millisecond times and micron length scales, without the need for accumulated deflections over long distances. Accordingly, we develop a theory of hydrodynamic forces on the fast time scale of bubble oscillation using the lubrication approximation, showing for the first time how particle displacements are rectified near moving boundaries over multiple oscillations in parallel with the generation of the steady streaming flow. The dependence of particle migration on particle size and the flow parameters is compared with experimental data. The theory is applicable to boundary streaming phenomena in general and demonstrates how particles can be sorted very quickly and without compromising device throughput. We acknowledge support by the National Science Foundation under grant number CBET-1236141.

  8. Evidence-Based Identification of Key Beliefs Explaining Infant Male Circumcision Motivation Among Expectant Parents in Zimbabwe: Targets for Behavior Change Messaging.

    Science.gov (United States)

    Montaño, Daniel E; Tshimanga, Mufuta; Hamilton, Deven T; Gorn, Gerald; Kasprzyk, Danuta

    2018-02-01

    Slow adult male circumcision uptake is one factor leading some to recommend increased priority for infant male circumcision (IMC) in sub-Saharan African countries. This research, guided by the integrated behavioral model (IBM), was carried out to identify key beliefs that best explain Zimbabwean parents' motivation to have their infant sons circumcised. A quantitative survey, designed from qualitative elicitation study results, was administered to independent representative samples of 800 expectant mothers and 795 expectant fathers in two urban and two rural areas in Zimbabwe. Multiple regression analyses found IMC motivation among fathers was explained by instrumental attitude, descriptive norm and self-efficacy; while motivation among mothers was explained by instrumental attitude, injunctive norm, descriptive norm, self-efficacy, and perceived control. Regression analyses of beliefs underlying IBM constructs found some overlap but many differences in key beliefs explaining IMC motivation among mothers and fathers. We found differences in key beliefs among urban and rural parents. Urban fathers' IMC motivation was explained best by behavioral beliefs, while rural fathers' motivation was explained by both behavioral and efficacy beliefs. Urban mothers' IMC motivation was explained primarily by behavioral and normative beliefs, while rural mothers' motivation was explained mostly by behavioral beliefs. The key beliefs we identified should serve as targets for developing messages to improve demand and maximize parent uptake as IMC programs are rolled out. These targets need to be different among urban and rural expectant mothers and fathers.

  9. Probing the nanoscale interaction forces and elastic properties of organic and inorganic materials using force-distance (F-D) spectroscopy

    Science.gov (United States)

    Vincent, Abhilash

    Due to their therapeutic applications such as radical scavenging, MRI contrast imaging, Photoluminescence imaging, drug delivery, etc., nanoparticles (NPs) have a significant importance in bio-nanotechnology. The reason that prevents the utilizing NPs for drug delivery in medical field is mostly due to their biocompatibility issues (incompatibility can lead to toxicity and cell death). Changes in the surface conditions of NPs often lead to NP cytotoxicity. Investigating the role of NP surface properties (surface charges and surface chemistry) on their interactions with biomolecules (Cells, protein and DNA) could enhance the current understanding of NP cytotoxicity. Hence, it is highly beneficial to the nanotechnology community to bring more attention towards the enhancement of surface properties of NPs to make them more biocompatible and less toxic to biological systems. Surface functionalization of NPs using specific ligand biomolecules have shown to enhance the protein adsorption and cellular uptake through more favorable interaction pathways. Cerium oxide NPs (CNPs also known as nanoceria) are potential antioxidants in cell culture models and understanding the nature of interaction between cerium oxide NPs and biological proteins and cells are important due to their therapeutic application (especially in site specific drug delivery systems). The surface charges and surface chemistry of CNPs play a major role in protein adsorption and cellular uptake. Hence, by tuning the surface charges and by selecting proper functional molecules on the surface, CNPs exhibiting strong adhesion to biological materials can be prepared. By probing the nanoscale interaction forces acting between CNPs and protein molecules using Atomic Force Microscopy (AFM) based force-distance (F-D) spectroscopy, the mechanism of CNP-protein adsorption and CNP cellular uptake can be understood more quantitatively. The work presented in this dissertation is based on the application of AFM in

  10. Beyond-proximity-force-approximation Casimir force between two spheres at finite temperature

    Science.gov (United States)

    Bimonte, Giuseppe

    2018-04-01

    A recent experiment [J. L. Garrett, D. A. T. Somers, and J. N. Munday, Phys. Rev. Lett. 120, 040401 (2018), 10.1103/PhysRevLett.120.040401] measured for the first time the gradient of the Casimir force between two gold spheres at room temperature. The theoretical analysis of the data was carried out using the standard proximity force approximation (PFA). A fit of the data, using a parametrization of the force valid for the sphere-plate geometry, was used by the authors to place a bound on deviations from PFA. Motivated by this work, we compute the Casimir force between two gold spheres at finite temperature. The semianalytic formula for the Casimir force that we construct is valid for all separations, and can be easily used to interpret future experiments in both the sphere-plate and sphere-sphere configurations. We describe the correct parametrization of the corrections to PFA for two spheres that should be used in data analysis.

  11. MOTIVATIONAL AND VALUE-SEMANTIC DETERMINANTS OF INDIVIDUAL ASSERTIVENESS

    Directory of Open Access Journals (Sweden)

    Инга Викторовна Лебедева

    2013-04-01

    Full Text Available The paper attempts to reveal the concept of "determinants of assertiveness" of a personality, which are determined by motivational characteristics and life value and meaning orientations of the individual. The immediate driving force of human action is the motive or the system of motives. The system of motives of human behavior in different situations of activities, communication and cognition is determined by the personal world view (set of ideas, interests, and beliefs. The value orientation, influencing the direction of human activity, determines a person's behavior and is a personality determinant in the manifestations of assertive behavior and assertiveness. Therefore, the significant psychological factors that contribute to the development of assertiveness are high motivation to success, positive attitudes, and such values as compassion, tolerance, mutual understanding, sympathy, concern that oppose to violence, domination, suppression and submission.The article also presents the results of an empirical study of motivational and value-semantic characteristics of the individual.DOI: http://dx.doi.org/10.12731/2218-7405-2013-4-15

  12. Mission possible? The performance of prosocially motivated employees depends on manager trustworthiness.

    Science.gov (United States)

    Grant, Adam M; Sumanth, John J

    2009-07-01

    The authors propose that in mission-driven organizations, prosocially motivated employees are more likely to perform effectively when trust cues enhance their perceptions of task significance. The authors develop and test a model linking prosocial motivation, trust cues, task significance, and performance across 3 studies of fundraisers using 3 different objective performance measures. In Study 1, perceiving managers as trustworthy strengthened the relationship between employees' prosocial motivation and performance, measured in terms of calls made. This moderated relationship was mediated by employees' perceptions of task significance. Study 2 replicated the interaction of manager trustworthiness and prosocial motivation in predicting a new measure of performance: dollars raised. It also revealed 3-way interactions between prosocial motivation, manager trustworthiness, and dispositional trust propensity, such that high trust propensity compensated for low manager trustworthiness to strengthen the association between employees' prosocial motivation and performance. Study 3 replicated all of the previous mediation and moderation findings in predicting initiative taken by professional fundraisers. Implications for work motivation, work design, and trust in organizations are discussed.

  13. Motivational study for an hybrid demonstrator

    International Nuclear Information System (INIS)

    Boidron, M.; Fiorini, G.L.; Thomas, J.B.

    2001-02-01

    This document recalls first the role of hybrid accelerator driven systems (ADS) in the domain of transmutation of long-lived fission products and minor actinides. It presents the specific contribution of these systems in the management of radioactive wastes and their technical feasibility and safety aspects. Then, follows a motivational analysis for the construction of a demonstration facility with its specifications and R and D needs: feasibility, schedule, links with other ADS-related programs, cost, international cooperation, recommendations. (J.S.)

  14. Current-induced forces: a simple derivation

    International Nuclear Information System (INIS)

    Todorov, Tchavdar N; Dundas, Daniel; Lü, Jing-Tao; Brandbyge, Mads; Hedegård, Per

    2014-01-01

    We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that—with the help of background literature—should be accessible to physics undergraduates. The discussion aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current—the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant features at the wire surface, making it a candidate for the nucleation of current-driven structural transformations and failure. Finally we discuss the problem of force noise and the limitations of Ehrenfest dynamics. (paper)

  15. In Search of Motivation for the Business Survey Response Task

    Directory of Open Access Journals (Sweden)

    Torres van Grinsven Vanessa

    2014-12-01

    Full Text Available Increasing reluctance of businesses to participate in surveys often leads to declining or low response rates, poor data quality and burden complaints, and suggests that a driving force, that is, the motivation for participation and accurate and timely response, is insufficient or lacking. Inspiration for ways to remedy this situation has already been sought in the psychological theory of self-determination; previous research has favored enhancement of intrinsic motivation compared to extrinsic motivation. Traditionally however, enhancing extrinsic motivation has been pervasive in business surveys. We therefore review this theory in the context of business surveys using empirical data from the Netherlands and Slovenia, and suggest that extrinsic motivation calls for at least as much attention as intrinsic motivation, that other sources of motivation may be relevant besides those stemming from the three fundamental psychological needs (competence, autonomy and relatedness, and that other approaches may have the potential to better explain some aspects of motivation in business surveys (e.g., implicit motives. We conclude with suggestions that survey organizations can consider when attempting to improve business survey response behavior.

  16. Intelligent networks recent approaches and applications in medical systems

    CERN Document Server

    Ahamed, Syed V

    2013-01-01

    This textbook offers an insightful study of the intelligent Internet-driven revolutionary and fundamental forces at work in society. Readers will have access to tools and techniques to mentor and monitor these forces rather than be driven by changes in Internet technology and flow of money. These submerged social and human forces form a powerful synergistic foursome web of (a) processor technology, (b) evolving wireless networks of the next generation, (c) the intelligent Internet, and (d) the motivation that drives individuals and corporations. In unison, the technological forces can tear

  17. Motivation and placebos: do different mechanisms occur in different contexts?

    Science.gov (United States)

    Hyland, Michael E

    2011-06-27

    This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic-pituitary-adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state.

  18. Motivational Function of Plans and Goals

    Directory of Open Access Journals (Sweden)

    Sabina Alispahić

    2013-10-01

    Full Text Available The academic literature shows that by helping tune out distractions, goals can get individuals' to try harder, work longer, and achieve more. Goals that people set for themselves and that are devoted to attaining mastery are usually healthy. But goals imposed by others—sales targets, quarterly returns, standardized test scores—can sometimes have dangerous side effects (Pink, 2009. Because understanding action demands understanding intention, the idea of motivation is natural and readily expressed in everyday language. Cognitive mental events like goals and expectancies can function as a “spring to action”, a moving force that energizes and directs action in purposive ways (Reeve, 2005. Cognitive studies of motivation are dealing with relationship between cognition and action. Literature is indicating a few cognitive elements that can have motivational significance. The article presents the overview of theory and research about the motivational function of plans and goals, according to Goal setting theory (Locke & Latham, 1990 and Self-determination Theory (Deci & Ryan, 2000. Suggestions for additional research are also indicated.

  19. A line driven Rayleigh-Taylor-type instability in hot stars

    International Nuclear Information System (INIS)

    Nelson, G.D.; Hearn, A.G.

    1978-01-01

    The existence of a Rayleigh-Taylor-type instability in the atmosphere of hot stars, driven by the radiative force associated with impurity ion resonance lines, is demonstrated. In a hot star with an effective temperature of 50 000 K, the instability will grow exponentially with a time scale of approximately 50 s in the layers where the stellar wind velocity is 5% of the thermal velocity of the ion. As a result, radially symmetric stellar winds driven by resonance line radiative forces will break up in small horizontal scale lengths. The energy fed into the instability provides a possible source of mechanical heating in the atmosphere for a chromosphere or corona. (orig.) [de

  20. Parents' food choice motives and their associations with children's food preferences.

    Science.gov (United States)

    Russell, Catherine G; Worsley, Anthony; Liem, Djin G

    2015-04-01

    The objective was to investigate parents' motives for selecting foods for their children and the associations between these motives and children's food preferences. Cross-sectional survey. A modified version of the Food Choice Questionnaire was used to assess parents' food choice motives. Parents also reported children's liking/disliking of 176 food and beverage items on 5-point Likert scales. Patterns of food choice motives were examined with exploratory principal component analysis. Associations between motives and children's food preferences were assessed with linear regression while one-way and two-way ANOVA were used to test for sociodemographic differences. Two Australian cities. Parents (n 371) of 2-5-year-old children. Health, nutrition and taste were key motivators for parents, whereas price, political concerns and advertising were among the motives considered least important. The more parents' food choice for their children was driven by what their children wanted, the less children liked vegetables (β =-0·27, Pfoods (r=0·17, Pmotives (vegetables β=0·17, Pmotives bordered on statistical significance as predictors of children's fruit and vegetable preferences. Although parents appear well intentioned in their motives for selecting children's foods, there are gaps to be addressed in the nature of such motives (e.g. selecting foods in line with the child's desires) or the translation of health motives into healthy food choices.

  1. Force sensing of multiple-DOF cable-driven instruments for minimally invasive robotic surgery.

    Science.gov (United States)

    He, Chao; Wang, Shuxin; Sang, Hongqiang; Li, Jinhua; Zhang, Linan

    2014-09-01

    Force sensing for robotic surgery is limited by the size of the instrument, friction and sterilization requirements. This paper presents a force-sensing instrument to avoid these restrictions. Operating forces were calculated according to cable tension. Mathematical models of the force-sensing system were established. A force-sensing instrument was designed and fabricated. A signal collection and processing system was constructed. The presented approach can avoid the constraints of space limits, sterilization requirements and friction introduced by the transmission parts behind the instrument wrist. Test results showed that the developed instrument has a 0.03 N signal noise, a 0.05 N drift, a 0.04 N resolution and a maximum error of 0.4 N. The validation experiment indicated that the operating and grasping forces can be effectively sensed. The developed force-sensing system can be used in minimally invasive robotic surgery to construct a force-feedback system. Copyright © 2013 John Wiley & Sons, Ltd.

  2. Harmonic Fluxes and Electromagnetic Forces of Concentric Winding Brushless Permanent Magnet Motor

    Science.gov (United States)

    Ishibashi, Fuminori; Takemasa, Ryo; Matsushita, Makoto; Nishizawa, Takashi; Noda, Shinichi

    Brushless permanent magnet motors have been widely used in home applications and industrial fields. These days, high efficiency and low noise motors are demanded from the view point of environment. Electromagnetic noise and iron loss of the motor are produced by the harmonic fluxes and electromagnetic forces. However, order and space pattern of these have not been discussed in detail. In this paper, fluxes, electromagnetic forces and magneto-motive forces of brushless permanent magnet motors with concentric winding were analyzed analytically, experimentally and numerically. Time harmonic fluxes and time electromagnetic forces in the air gap were measured by search coils on the inner surface of the stator teeth and analyzed by FEM. Space pattern of time harmonic fluxes and time electromagnetic forces were worked out with experiments and FEM. Magneto motive forces due to concentric winding were analyzed with equations and checked by FEM.

  3. Measurement of beam driven hydrodynamic turbulence

    International Nuclear Information System (INIS)

    Norem, J.; Black, E.; Bandura, L.; Errede, D.; Cummings, M. A. C.

    2003-01-01

    Cooling intense muon beams in liquid hydrogen absorbers introduces kW of heating to the cold fluid, which will drive turbulent flow. The amount of turbulence may be sufficient to help cool the liquid, but calculations are difficult. We have used a 20 MeV electron beam in a water tank to look at the scale of the beam driven convection and turbulence. The density and flow measurements are made with schlieren and Ronchi systems. We describe the optical systems and the turbulence measured. These data are being used to calibrate hydrodynamic calculations of convection driven and forced flow cooling in muon cooling absorbers

  4. Global ocean carbon uptake: magnitude, variability and trends

    Directory of Open Access Journals (Sweden)

    R. Wanninkhof

    2013-03-01

    Full Text Available The globally integrated sea–air anthropogenic carbon dioxide (CO2 flux from 1990 to 2009 is determined from models and data-based approaches as part of the Regional Carbon Cycle Assessment and Processes (RECCAP project. Numerical methods include ocean inverse models, atmospheric inverse models, and ocean general circulation models with parameterized biogeochemistry (OBGCMs. The median value of different approaches shows good agreement in average uptake. The best estimate of anthropogenic CO2 uptake for the time period based on a compilation of approaches is −2.0 Pg C yr−1. The interannual variability in the sea–air flux is largely driven by large-scale climate re-organizations and is estimated at 0.2 Pg C yr−1 for the two decades with some systematic differences between approaches. The largest differences between approaches are seen in the decadal trends. The trends range from −0.13 (Pg C yr−1 decade−1 to −0.50 (Pg C yr−1 decade−1 for the two decades under investigation. The OBGCMs and the data-based sea–air CO2 flux estimates show appreciably smaller decadal trends than estimates based on changes in carbon inventory suggesting that methods capable of resolving shorter timescales are showing a slowing of the rate of ocean CO2 uptake. RECCAP model outputs for five decades show similar differences in trends between approaches.

  5. The fifth force: A personal history

    Science.gov (United States)

    Fischbach, Ephraim

    2015-12-01

    On January 6, 1986, a paper written by our group appeared in Physical Review Letters entitled "Reanalysis of the Eötvös Experiment". In that Letter we reanalyzed a well-known 1922 paper by Eötvös, Pekár, and Fekete (EPF) which compared the accelerations of samples of different composition to the Earth. Our surprising conclusion was that "Although the Eötvös experiment has been universally interpreted as having given null results, we find in fact that this is not the case". Two days later a front page story appeared in the New York Times under the headline "Hints of 5th Force in Universe Challenge Galileo's Findings", and so was born the concept of a "fifth force". In this personal history I review the pre-history which motivated our paper, and discuss details of our reanalysis of the EPF paper that have not been presented previously. Our work led to illuminating correspondence with Robert Dicke and Richard Feynman which are presented here for the first time. I also discuss an interesting meeting with T.D. Lee, one of whose papers with C.N. Yang provided part of the theoretical motivation for our work. Although there is almost no support from the many experiments motivated by the EPF data for a fifth force with properties similar to those that we hypothesized in our original paper, interest in the EPF experiment continues for reasons I outline in the Epilogue.

  6. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δψ and ΔpH.

    Science.gov (United States)

    Davis, Geoffry A; Rutherford, A William; Kramer, David M

    2017-09-26

    There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching ( q E ), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δ ψ ) induce photosystem II recombination reactions that produce damaging singlet oxygen ( 1 O 2 ). Both q E and FRIP are directly linked to the thylakoid proton motive force ( pmf ), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δ ψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δ ψ and formation of ΔpH. This would result in increased rates for the formation and decay of q E while resulting in a more rapid decline in the amplitudes of Δ ψ -spikes and decreasing 1 O 2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo , while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis

  7. Protein-Ligand Informatics Force Field (PLIff): Toward a Fully Knowledge Driven "Force Field" for Biomolecular Interactions.

    Science.gov (United States)

    Verdonk, Marcel L; Ludlow, R Frederick; Giangreco, Ilenia; Rathi, Prakash Chandra

    2016-07-28

    The Protein Data Bank (PDB) contains a wealth of data on nonbonded biomolecular interactions. If this information could be distilled down to nonbonded interaction potentials, these would have some key advantages over standard force fields. However, there are some important outstanding issues to address in order to do this successfully. This paper introduces the protein-ligand informatics "force field", PLIff, which begins to address these key challenges ( https://bitbucket.org/AstexUK/pli ). As a result of their knowledge-based nature, the next-generation nonbonded potentials that make up PLIff automatically capture a wide range of interaction types, including special interactions that are often poorly described by standard force fields. We illustrate how PLIff may be used in structure-based design applications, including interaction fields, fragment mapping, and protein-ligand docking. PLIff performs at least as well as state-of-the art scoring functions in terms of pose predictions and ranking compounds in a virtual screening context.

  8. Origin of Knudsen forces on heated microbeams

    KAUST Repository

    Zhu, Taishan

    2010-09-09

    The presented work probes the fundamentals of Knudsen forces. Using the direct simulation Monte Carlo (DSMC) method, the flows induced by temperature inhomogeneity within a representative configuration and the Knudsen force acting on a heated microbeam are captured as functions of Knudsen number in the entire flow regime. Both flow strength and Knudsen force peak in the transition regime and negative Knudsen force absent in experimental data is observed. The mechanisms of the thermally induced flows and Knudsen forces are studied. It has been found that thermal edge flow is the main driven source for the formation of the Knudsen force on microbeams and domain configuration plays an important role in the process.

  9. Profiling physical activity motivation based on self-determination theory: a cluster analysis approach.

    Science.gov (United States)

    Friederichs, Stijn Ah; Bolman, Catherine; Oenema, Anke; Lechner, Lilian

    2015-01-01

    In order to promote physical activity uptake and maintenance in individuals who do not comply with physical activity guidelines, it is important to increase our understanding of physical activity motivation among this group. The present study aimed to examine motivational profiles in a large sample of adults who do not comply with physical activity guidelines. The sample for this study consisted of 2473 individuals (31.4% male; age 44.6 ± 12.9). In order to generate motivational profiles based on motivational regulation, a cluster analysis was conducted. One-way analyses of variance were then used to compare the clusters in terms of demographics, physical activity level, motivation to be active and subjective experience while being active. Three motivational clusters were derived based on motivational regulation scores: a low motivation cluster, a controlled motivation cluster and an autonomous motivation cluster. These clusters differed significantly from each other with respect to physical activity behavior, motivation to be active and subjective experience while being active. Overall, the autonomous motivation cluster displayed more favorable characteristics compared to the other two clusters. The results of this study provide additional support for the importance of autonomous motivation in the context of physical activity behavior. The three derived clusters may be relevant in the context of physical activity interventions as individuals within the different clusters might benefit most from different intervention approaches. In addition, this study shows that cluster analysis is a useful method for differentiating between motivational profiles in large groups of individuals who do not comply with physical activity guidelines.

  10. Intrinsic-extrinsic factors in sport motivation.

    Science.gov (United States)

    Pedersen, Darhl M

    2002-10-01

    Participants were 83 students (36 men and 47 women). 10 intrinsic-extrinsic factors involved in sport motivation were obtained. The factors were generated from items obtained from the participants rather than items from the experimenter. This was done to avoid the possible influence of preconceptions on the part of the experimenter regarding what the final dimensions may be. Obtained motivational factors were Social Reinforcement, Fringe Benefits, Fame and Fortune, External Forces, Proving Oneself, Social Benefits, Mental Enrichment, Expression of Self, Sense of Accomplishment, and Self-enhancement. Each factor was referred to an intrinsic-extrinsic dimension to describe its relative position on that dimension. The order of the factors as listed indicates increasing intrinsic motivation. i.e., the first four factors were rated in the extrinsic range, whereas the remaining six were rated to be in the intrinsic range. Next, the participants rated the extent to which each of the various factors was involved in their decision to participate in sport activities. The pattern of use of the motivational factors was the same for both sexes except that men indicated greater use of the Fringe Benefits factor. Overall, the more intrinsic a sport motivation factor was rated, the more likely it was to be rated as a factor in actual sport participation.

  11. Heisenberg equation for a nonrelativistic particle on a hypersurface: From the centripetal force to a curvature induced force

    Directory of Open Access Journals (Sweden)

    D. K. Lian

    2017-12-01

    Full Text Available In classical mechanics, a nonrelativistic particle constrained on an N − 1 curved hypersurface embedded in N flat space experiences the centripetal force only. In quantum mechanics, the situation is totally different for the presence of the geometric potential. We demonstrate that the motion of the quantum particle is ”driven” by not only the centripetal force, but also a curvature induced force proportional to the Laplacian of the mean curvature, which is fundamental in the interface physics, causing curvature driven interface evolution.

  12. Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

    International Nuclear Information System (INIS)

    Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

    2004-01-01

    In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. Tritium decontamination, by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying motivational forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

  13. People trying to lose weight dislike calorie counting apps and want motivational support to help them achieve their goals

    Directory of Open Access Journals (Sweden)

    Linda Solbrig

    2017-03-01

    Conclusion: There is a mismatch between the help provided via public health information campaigns and commercially available weight-loss self-help (lifestyle information, self-monitoring, and the help that individuals actually desire (motivational and autonomous e-support, posing an opportunity to develop more effective electronic, theory-driven, motivational, self-help interventions.

  14. Simulation of a force on force exercise

    International Nuclear Information System (INIS)

    Terhune, R.; Van Slyke, D.; Sheppard, T.; Brandrup, M.

    1988-01-01

    The Security Exercise Evaluation System (SEES) is under development for use in planning Force on Force exercises and as an aid in post-exercise evaluation. This study is part of the development cycle where the simulation results are compared to field data to provide guidance for further development of the model. SEES is an event-driven stochastic computer program simulating individual movement and combat within an urban terrain environment. The simulator models the physics of movement, line of sight, and weapon effects. It relies on the controllers to provide all knowledge of security tactics, which are entered by the controllers during the simulation using interactive color graphic workstations. They are able to develop, modify and implement plans promptly as the simulator maintains real time. This paper reports on how SEES will be used to develop an intrusion plan, test the security response tactics and develop observer logistics. A Force on Force field exercise will then be executed to follow the plan with observations recorded. An analysis is made by first comparing the plan and events of the simulation with the field exercise, modifying the simulation plan to match the actual field exercise, and then running the simulation to develop a distribution of possible outcomes

  15. Effect of Forcing Function on Nonlinear Acoustic Standing Waves

    Science.gov (United States)

    Finkheiner, Joshua R.; Li, Xiao-Fan; Raman, Ganesh; Daniels, Chris; Steinetz, Bruce

    2003-01-01

    Nonlinear acoustic standing waves of high amplitude have been demonstrated by utilizing the effects of resonator shape to prevent the pressure waves from entering saturation. Experimentally, nonlinear acoustic standing waves have been generated by shaking an entire resonating cavity. While this promotes more efficient energy transfer than a piston-driven resonator, it also introduces complicated structural dynamics into the system. Experiments have shown that these dynamics result in resonator forcing functions comprised of a sum of several Fourier modes. However, previous numerical studies of the acoustics generated within the resonator assumed simple sinusoidal waves as the driving force. Using a previously developed numerical code, this paper demonstrates the effects of using a forcing function constructed with a series of harmonic sinusoidal waves on resonating cavities. From these results, a method will be demonstrated which allows the direct numerical analysis of experimentally generated nonlinear acoustic waves in resonators driven by harmonic forcing functions.

  16. Cancer: a profit-driven biosystem?

    Science.gov (United States)

    Deisboeck, Thomas S

    2008-08-01

    The argument is made that solid malignant tumors behave as profit-driven biological systems in that they expand their nutrient-uptaking surface to increase energetic revenue, at a comparably low metabolic cost. Within this conceptual framework, cancer cell migration is a critical mechanism as it maximizes systemic surface expansion while minimizing diffusion distance. Treating these tumor systems with adjuvant anti-proliferative regimen only should increase the energetic net gain of the viable cancer cells left behind, hence would facilitate tumor recurrence. Therapeutic attempts to better control tumor (re)growth should therefore aim primarily at containing its surface expansion, thus reducing its energetic revenue, or increasing its metabolic costs or better yet, both.

  17. Manipulating bubbles with secondary Bjerknes forces

    Energy Technology Data Exchange (ETDEWEB)

    Lanoy, Maxime [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France); Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Derec, Caroline; Leroy, Valentin [Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Tourin, Arnaud [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France)

    2015-11-23

    Gas bubbles in a sound field are submitted to a radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us to investigate in detail this force between two bubbles, as a function of the sonication frequency, as well as the bubbles radii and distance. We report the observation of both attractive and, more interestingly, repulsive Bjerknes force, when the two bubbles are driven in antiphase. Our experiments show the importance of taking multiple scatterings into account, which leads to a strong acoustic coupling of the bubbles when their radii are similar. Our setup demonstrates the accuracy of secondary Bjerknes forces for attracting or repealing a bubble, and could lead to new acoustic tools for noncontact manipulation in microfluidic devices.

  18. Manipulating bubbles with secondary Bjerknes forces

    International Nuclear Information System (INIS)

    Lanoy, Maxime; Derec, Caroline; Leroy, Valentin; Tourin, Arnaud

    2015-01-01

    Gas bubbles in a sound field are submitted to a radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us to investigate in detail this force between two bubbles, as a function of the sonication frequency, as well as the bubbles radii and distance. We report the observation of both attractive and, more interestingly, repulsive Bjerknes force, when the two bubbles are driven in antiphase. Our experiments show the importance of taking multiple scatterings into account, which leads to a strong acoustic coupling of the bubbles when their radii are similar. Our setup demonstrates the accuracy of secondary Bjerknes forces for attracting or repealing a bubble, and could lead to new acoustic tools for noncontact manipulation in microfluidic devices

  19. Wall relaxation and the driving forces for cell expansive growth

    Science.gov (United States)

    Cosgrove, D. J.

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  20. Taking chances in the face of threat: romantic risk regulation and approach motivation.

    Science.gov (United States)

    Cavallo, Justin V; Fitzsimons, Gráinne M; Holmes, John G

    2009-06-01

    Four studies examine the hypothesis that goals adopted by high and low self-esteem people (HSEs and LSEs) to manage risk in romantic relationships may reflect global shifts in approach motivation and subsequently affect risk taking in nonsocial domains. In Studies 1 and 2, threats to participants' romantic relationships heightened HSEs' self-reported general approach motivation while lowering LSEs' approach motivation. In Studies 2 through 4, HSEs exhibited riskier decision making (i.e., a greater tendency to pursue rewards and ignore risks) in nonsocial domains following a relationship threat manipulation whereas LSEs made more conservative decisions. These results suggest that the romantic risk regulation may be inherently linked to a broader approach and avoidance system and that specific risk regulation behaviors may be driven by global motivational shifts to a greater degree than previously theorized.

  1. Hybrid insolation forcing of Pliocene monsoon dynamics in West Africa

    Directory of Open Access Journals (Sweden)

    R. R. Kuechler

    2018-01-01

    Full Text Available The Pliocene is regarded as a potential analogue for future climate with conditions generally warmer-than-today and higher-than-preindustrial atmospheric CO2 levels. Here we present the first orbitally resolved records of continental hydrology and vegetation changes from West Africa for two Pliocene time intervals (5.0–4.6 Ma, 3.6–3.0 Ma, which we compare with records from the last glacial cycle (Kuechler et al., 2013. Our results indicate that changes in local insolation alone are insufficient to explain the full degree of hydrologic variations. Generally two modes of interacting insolation forcings are observed: during eccentricity maxima, when precession was strong, the West African monsoon was driven by summer insolation; during eccentricity minima, when precession-driven variations in local insolation were minimal, obliquity-driven changes in the summer latitudinal insolation gradient became dominant. This hybrid monsoonal forcing concept explains orbitally controlled tropical climate changes, incorporating the forcing mechanism of latitudinal gradients for the Pliocene, which probably increased in importance during subsequent Northern Hemisphere glaciations.

  2. External radioactive markers for PET data-driven respiratory gating in positron emission tomography.

    Science.gov (United States)

    Büther, Florian; Ernst, Iris; Hamill, James; Eich, Hans T; Schober, Otmar; Schäfers, Michael; Schäfers, Klaus P

    2013-04-01

    Respiratory gating is an established approach to overcoming respiration-induced image artefacts in PET. Of special interest in this respect are raw PET data-driven gating methods which do not require additional hardware to acquire respiratory signals during the scan. However, these methods rely heavily on the quality of the acquired PET data (statistical properties, data contrast, etc.). We therefore combined external radioactive markers with data-driven respiratory gating in PET/CT. The feasibility and accuracy of this approach was studied for [(18)F]FDG PET/CT imaging in patients with malignant liver and lung lesions. PET data from 30 patients with abdominal or thoracic [(18)F]FDG-positive lesions (primary tumours or metastases) were included in this prospective study. The patients underwent a 10-min list-mode PET scan with a single bed position following a standard clinical whole-body [(18)F]FDG PET/CT scan. During this scan, one to three radioactive point sources (either (22)Na or (18)F, 50-100 kBq) in a dedicated holder were attached the patient's abdomen. The list mode data acquired were retrospectively analysed for respiratory signals using established data-driven gating approaches and additionally by tracking the motion of the point sources in sinogram space. Gated reconstructions were examined qualitatively, in terms of the amount of respiratory displacement and in respect of changes in local image intensity in the gated images. The presence of the external markers did not affect whole-body PET/CT image quality. Tracking of the markers led to characteristic respiratory curves in all patients. Applying these curves for gated reconstructions resulted in images in which motion was well resolved. Quantitatively, the performance of the external marker-based approach was similar to that of the best intrinsic data-driven methods. Overall, the gain in measured tumour uptake from the nongated to the gated images indicating successful removal of respiratory motion

  3. In Search of Motivation for the Business Survey Response Task

    OpenAIRE

    Torres van Grinsven Vanessa; Bolko Irena; Bavdaž Mojca

    2014-01-01

    Increasing reluctance of businesses to participate in surveys often leads to declining or low response rates, poor data quality and burden complaints, and suggests that a driving force, that is, the motivation for participation and accurate and timely response, is insufficient or lacking. Inspiration for ways to remedy this situation has already been sought in the psychological theory of self-determination; previous research has favored enhancement of intrinsic motivation compared to extrinsi...

  4. Contextualizing educational differences in "vaccination uptake": A thirty nation survey.

    Science.gov (United States)

    Makarovs, Kirils; Achterberg, Peter

    2017-09-01

    This paper addresses the issue of public acceptance of vaccination with specific attention being paid to the role of education in vaccine uptake. Using Flash Eurobarometer 287 (2009) survey data and exploring it through the lens of Beck's reflexive modernization and Roger's protection motivation theories we examined how individual-level factors affect intention to get vaccinated, particularly aimed at examining whether higher education predicts more or less vaccination intention in different societies. The empirical results support an idea that at least for seasonal flu educational differences in vaccination uptake are contextual upon the reflexivity of the society in which respondent happens to live. Educated people living in more reflexive modernized countries tend to oppose vaccination against seasonal flu more that those highly educated living in less advanced societies, indicating that skeptical attitude towards science that is intrinsic to the modern post-industrial nations induces the immunization opposition among most informed and distrustful social group. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Improving the translation of intentions into health actions: The role of motivational coherence.

    Science.gov (United States)

    Sheeran, Paschal; Conner, Mark

    2017-11-01

    This paper introduces a new construct termed motivational coherence , and tests its influence upon the process of translating intentions into health actions. Motivational coherence was defined as the extent to which predictors of intentions (e.g., attitudes, norms, perceived control) cohere or point in the same direction. The prediction tested was that motivational coherence would stabilize intentions and thereby increase intention-behavior consistency. Three studies were conducted that each involved prospective designs. Study 1 (N = 248) concerned breastfeeding among nulliparous, low-income women. Study 2 (N = 651) concerned physical activity, and Study 3 (N = 635) examined uptake of smoking among adolescents. Motivational coherence moderated intention-behavior relations in all 3 studies. Greater motivational coherence was associated with a stronger relationship between intentions and action. This finding also held when other predictors of intention (Studies 1-3) and past behavior (Studies 2-3) were taken into account. Study 3 tested and found support for the idea that temporal stability of intention mediated the moderating effect of motivational coherence. The present studies suggest that future research on predicting health behaviors should consider not only the strength of people's intentions to act but also whether the basis of respective intentions is motivationally coherent. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Surface radiative forcing of forest disturbances over northeastern China

    International Nuclear Information System (INIS)

    Zhang, Yuzhen; Liang, Shunlin

    2014-01-01

    Forests provide important climate forcing through biogeochemical and biogeophysical processes. In this study, we investigated the climatic effects of forest disturbances due to changes in forest biomass and surface albedo in terms of radiative forcing over northeastern China. Four types of forest disturbances were considered: fires, insect damage, logging, and afforestation and reforestation. The mechanisms of the influence of forest disturbances on climate were different. ‘Instantaneous’ net radiative forcings caused by fires, insect damage, logging, and afforestation and reforestation were estimated at 0.53 ± 0.08 W m −2 , 1.09 ± 0.14 W m −2 , 2.23 ± 0.27 W m −2 , and 0.14 ± 0.04 W m −2 , respectively. Trajectories of CO 2 -driven radiative forcing, albedo-driven radiative forcing, and net forcing were different with time for each type of disturbance. Over a decade, the estimated net forcings were 2.24 ± 0.11 W m −2 , 0.20 ± 0.31 W m −2 , 1.06 ± 0.41 W m −2 , and −0.47 ± 0.07 W m −2 , respectively. These estimated radiative forcings from satellite observations provided evidence for the mechanisms of the influences of forest disturbances on climate. (paper)

  7. Classical dynamics with curl forces, and motion driven by time-dependent flux

    International Nuclear Information System (INIS)

    Berry, M V; Shukla, Pragya

    2012-01-01

    For position-dependent forces whose curl is non-zero (‘curl forces’), there is no associated scalar potential and therefore no obvious Hamiltonian or Lagrangean and, except in special cases, no obvious conserved quantities. Nevertheless, the motion is nondissipative (measure-preserving in position and velocity). In a class of planar motions, some of which are exactly solvable, the curl force is directed azimuthally with a magnitude varying with radius, and the orbits are usually spirals. If the curl is concentrated at the origin (for example, the curl force could be an electric field generated by a changing localized magnetic flux, as in the betatron), a Hamiltonian does exist but violates the rotational symmetry of the force. In this case, reminiscent of the Aharonov–Bohm effect, the spiralling is extraordinarily slow. (paper)

  8. Going hybrid: An analysis of consumer purchase motivations

    International Nuclear Information System (INIS)

    Ozaki, Ritsuko; Sevastyanova, Katerina

    2011-01-01

    What makes consumers adopt energy-sustainable innovations? The uptake of such products and technologies is of importance, particularly at a time when climate change, diminishing energy resources and energy security are urgent issues. This paper reports on a case study of consumer adoption of hybrid vehicles, a green innovation that has been in the market since the late 1990s. The study is based on a questionnaire survey, conducted in 2009 in collaboration with Toyota GB, to investigate the dimensions that constitute motivations to purchase the Prius and to examine how policy can encourage hybrid adoption. The survey yielded 1484 responses, 1263 of which were used for the analysis; the results of the exploratory factor analyses provide information on consumer purchase motivations. The financial benefits related to transport policy are an important factor in consumer hybrid purchase motivations, and social norms and consumers' willingness to comply with the norms of their groups influence the purchase decision. We also find that various meanings are attached to hybrid vehicle ownership, and practical, experiential and affective values need to be communicated to consumers in terms of value added.

  9. Optogenetic Inhibition of Ventral Pallidum Neurons Impairs Context-Driven Salt Seeking.

    Science.gov (United States)

    Chang, Stephen E; Smedley, Elizabeth B; Stansfield, Katherine J; Stott, Jeffrey J; Smith, Kyle S

    2017-06-07

    Salt appetite, in which animals can immediately seek out salt when under a novel state of sodium deprivation, is a classic example of how homeostatic systems interface with learned associations to produce an on-the-fly updating of motivated behavior. Neural activity in the ventral pallidum (VP) has been shown to encode changes in the value of salt under such conditions, both the value of salt itself (Tindell et al., 2006) and the motivational value of its predictive cues (Tindell et al., 2009; Robinson and Berridge, 2013). However, it is not known whether the VP is necessary for salt appetite in terms of seeking out salt or consuming salt following sodium depletion. Here, we used a conditioned place-preference procedure to investigate the effects of optogenetically inhibiting the VP on context-driven salt seeking and the consumption of salt following deprivation. Male rats learned to associate one context with sucrose and another context with less-desirable salt. Following sodium depletion, and in the absence of either sucrose or salt, we found that inhibiting the VP selectively reduced the elevation in time spent in the salt-paired context. VP inhibition had minimal effects on the consumption of salt once it was made available. To our knowledge, this is the first evidence that the VP or any brain region is necessary for the ability to use contextual cues to guide salt seeking. These results highlight a dissociation between deficit-driven reward seeking and reward consumption to replenish those deficits, with the former process being particularly sensitive to on-line VP activity. SIGNIFICANCE STATEMENT Salt appetite, in which rats will immediately seek out a once-undesirable concentrated salt solution after being depleted of bodily sodium despite never having tasted salt as a positive reward, is a phenomenon showing how animals can update their motivational goals without any new learning or conditioning. This salt-seeking behavior is also observed when the animal

  10. Remark on the role of the driving force in BWR instability

    International Nuclear Information System (INIS)

    Dykin, V.; Pazsit, I.

    2009-01-01

    Simple models of BWR instability, used e.g. in understanding the role of the various oscillation modes in the overall stability of the plant, assume that each oscillation mode can be described by a second order system (a damped harmonic oscillator) driven by a white noise driving force. Change of the decay ratio (DR) of the observed signal is, as a rule, associated with the changing of the parameters of the damped oscillator, mainly its damping coefficient, and is interpreted in terms of the change of the stability of the system. However, conceptually, one cannot exclude cases when the change of the response of a driven damped oscillator is due to the change of the properties of the driving force. In this work we investigate the effect of a non-white driving force on the behaviour of the system. A question of interest is how changes of the spectrum of the driving force influence the observed autocorrelation function (ACF) of the resulting signal. Hence we calculate the response of a damped harmonic oscillator driven by a non-white driving force, corresponding to the reactivity effect of propagating density fluctuations in two-phase flow. It is shown how in some special cases such a driving force, when interpreting the neutron noise as if induced by a white noise driving source, can lead to an erroneous conclusion regarding the stability of the system. It is also concluded that in the practically interesting cases the effect of the coloured driving force, arising from propagating density fluctuations, is negligible.

  11. Driven motion of vortices in superconductors

    International Nuclear Information System (INIS)

    Crabtree, G.W.; Leaf, G.K.; Kaper, H.G.; Vinokur, V.M.; Koshelev, A.E.; Braun, D.W.; Levine, D.M.

    1995-09-01

    The driven motion of vortices in the solid vortex state is analyzed with the time-dependent Ginzburg-Landau equations. In large-scale numerical simulations, carried out on the IBM Scalable POWERparallel (SP) system at Argonne National Laboratory, many hundreds of vortices are followed as they move under the influence of a Lorentz force induced by a transport current in the presence of a planar defect (similar to a twin boundary in YBa 2 CU 3 O 7 ). Correlations in the positions and velocities of the vortices in plastic and elastic motion are identified and compared. Two types of plastic motion are observed. Organized plastic motion displaying long-range orientational correlation and shorter-range velocity correlation occurs when the driving forces are small compared to the pinning forces in the twin boundary. Disorganized plastic motion displaying no significant correlation in either the velocities or orientation of the vortex system occurs when the driving and pinning forces axe of the same order

  12. Pi-kinks in a parametrically driven sine-Gordon chain

    DEFF Research Database (Denmark)

    Kivshar, Yuri S.; Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1992-01-01

    We consider the sine-Gordon chain driven by a high-frequency parametric force in the presence of loss. Using an analytical approach based on the method of averaging in fast oscillations, we predict that such a parametric force may support propagation of π kinks, which are unstable in the standard...... sine-Gordon model. The steady-state velocity of the π kinks is calculated, and the analytical results are in good agreement with direct numerical simulations....

  13. Typology and Hierarchy of Students’ Motivations to Use Technology in Learning

    Directory of Open Access Journals (Sweden)

    Kenneth J Stevens

    2018-03-01

    Full Text Available Considerable discussion has taken place in practice and academe regarding the need for changes to the educational system to better suit current student’s approaches and preferences for technology use in learning. Much of this discussion involves assumptions about the current students (referred to by some as ‘digital natives’ preference for independent learning and that students are motivated in similar ways to use technology to achieve and support their preferred learning style. This study sought to better understand student’s motivations for technology use in learning and whether assumptions about the homogeneity of motivations are warranted. We sought to identify students’ motivation typology and any groupings within these typologies, and understand the inter-relationship between motivations. Using data collected from 16 Information Systems (IS students via the Repertory Grid Interview technique (RGT, a cluster analysis segmented respondents into two distinct groups: ‘Independent Learners’ and ‘Traditional Learners’. A hierarchical framework of technology use motivations was developed for each group using Interpretive Structural Modelling (ISM and Cross-impact Matrix Multiplication Applied to Classification (MICMAC was used to categorise each group’s motivation factors. Results show that the two groups were driven to achieve the same learning goals by different paths and hence questioning the assumption of homogeneity in technology use motivations among the current student cohort.

  14. Molecular Force Spectroscopy on Cells

    Science.gov (United States)

    Liu, Baoyu; Chen, Wei; Zhu, Cheng

    2015-04-01

    Molecular force spectroscopy has become a powerful tool to study how mechanics regulates biology, especially the mechanical regulation of molecular interactions and its impact on cellular functions. This force-driven methodology has uncovered a wealth of new information of the physical chemistry of molecular bonds for various biological systems. The new concepts, qualitative and quantitative measures describing bond behavior under force, and structural bases underlying these phenomena have substantially advanced our fundamental understanding of the inner workings of biological systems from the nanoscale (molecule) to the microscale (cell), elucidated basic molecular mechanisms of a wide range of important biological processes, and provided opportunities for engineering applications. Here, we review major force spectroscopic assays, conceptual developments of mechanically regulated kinetics of molecular interactions, and their biological relevance. We also present current challenges and highlight future directions.

  15. Mathematical modeling of compression processes in air-driven boosters

    International Nuclear Information System (INIS)

    Li Zeyu; Zhao Yuanyang; Li Liansheng; Shu Pengcheng

    2007-01-01

    The compressed air in normal pressure is used as the source of power of the air-driven booster. The continuous working of air-driven boosters relies on the difference of surface area between driven piston and driving piston, i.e., the different forces acting on the pistons. When the working surface area of the driving piston for providing power is greater than that of the driven piston for compressing gas, the gas in compression chamber will be compressed. On the basis of the first law of thermodynamics, the motion regulation of piston is analyzed and the mathematical model of compression processes is set up. Giving a calculating example, the vary trends of gas pressure and pistons' move in working process of booster have been gotten. The change of parameters at different working conditions is also calculated and compared. And the corresponding results can be referred in the design of air-driven boosters

  16. Student Perceptions of Motivational Behaviors of Instructions in a Military Setting

    National Research Council Canada - National Science Library

    Antoline, Anthony F

    2005-01-01

    .... More superficially, the study assessed the extent to which United States Air Force Air and Space Basic Course instructors exhibit motivational behaviors and whether those behaviors influence student achievement...

  17. Ice-Shelf Flexure and Tidal Forcing of Bindschadler Ice Stream, West Antarctica

    Science.gov (United States)

    Walker, Ryan T.; Parizek, Bryron R.; Alley, Richard B.; Brunt, Kelly M.; Anandakrishnan, Sridhar

    2014-01-01

    Viscoelastic models of ice-shelf flexure and ice-stream velocity perturbations are combined into a single efficient flowline model to study tidal forcing of grounded ice. The magnitude and timing of icestream response to tidally driven changes in hydrostatic pressure and/or basal drag are found to depend significantly on bed rheology, with only a perfectly plastic bed allowing instantaneous velocity response at the grounding line. The model can reasonably reproduce GPS observations near the grounding zone of Bindschadler Ice Stream (formerly Ice Stream D) on semidiurnal time scales; however, other forcings such as tidally driven ice-shelf slope transverse to the flowline and flexurally driven till deformation must also be considered if diurnal motion is to be matched

  18. Entropic transport of active particles driven by a transverse ac force

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian-chun, E-mail: wjchun2010@163.com; Chen, Qun; Ai, Bao-quan, E-mail: aibq@scnu.edu.cn

    2015-12-18

    Transport of active particles is numerically investigated in a two-dimensional period channel. In the presence of a transverse ac force, the directed transport of active particles demonstrates striking behaviors. By adjusting the amplitude and the frequency of the transverse ac force, the average velocity will be influenced significantly and the direction of the transport can be reversed several times. Remarkably, it is also found that the direction of the transport varies with different self-propelled speeds. Therefore, particles with different self-propelled speeds will move to the different directions, which is able to separate particles of different self-propelled speeds. - Highlights: • A transverse ac force strongly influence the transport of active particles. • The direction of the transport can be reversed several times. • Active particles with different self-propelled speeds can be separated.

  19. Emotion, motivation, and cardiovascular response

    OpenAIRE

    Kreibig Sylvia D

    2012-01-01

    Cardiovascular (CV) response consists of changes in CV parameters such as heart rate blood pressure and heart contraction force in reaction to an event or set of events. It is significant for multiple reasons perhaps most notably because research suggests that it affects the development and progression of heart disease. Disease models vary but most assume that characteristically strong and prolonged CV responses confer health risk. Psychologists have long suspected linkages between motivation...

  20. Supervised learning in spiking neural networks with FORCE training.

    Science.gov (United States)

    Nicola, Wilten; Clopath, Claudia

    2017-12-20

    Populations of neurons display an extraordinary diversity in the behaviors they affect and display. Machine learning techniques have recently emerged that allow us to create networks of model neurons that display behaviors of similar complexity. Here we demonstrate the direct applicability of one such technique, the FORCE method, to spiking neural networks. We train these networks to mimic dynamical systems, classify inputs, and store discrete sequences that correspond to the notes of a song. Finally, we use FORCE training to create two biologically motivated model circuits. One is inspired by the zebra finch and successfully reproduces songbird singing. The second network is motivated by the hippocampus and is trained to store and replay a movie scene. FORCE trained networks reproduce behaviors comparable in complexity to their inspired circuits and yield information not easily obtainable with other techniques, such as behavioral responses to pharmacological manipulations and spike timing statistics.

  1. Parent-Driven Campaign Videos: An Analysis of the Motivation and Affect of Videos Created by Parents of Children With Complex Healthcare Needs.

    Science.gov (United States)

    Carter, Bernie; Bray, Lucy; Keating, Paula; Wilkinson, Catherine

    2017-09-15

    Caring for a child with complex health care needs places additional stress and time demands on parents. Parents often turn to their peers to share their experiences, gain support, and lobby for change; increasingly this is done through social media. The WellChild #notanurse_but is a parent-driven campaign that states its aim is to "shine a light" on the care parents, who are not nurses, have to undertake for their child with complex health care needs and to raise decision-makers' awareness of the gaps in service provision and support. This article reports on a study that analyzed the #notanurse_but parent-driven campaign videos. The purpose of the study was to consider the videos in terms of the range, content, context, perspectivity (motivation), and affect (sense of being there) in order to inform the future direction of the campaign. Analysis involved repeated viewing of a subset of 30 purposively selected videos and documenting our analysis on a specifically designed data extraction sheet. Each video was analyzed by a minimum of 2 researchers. All but 2 of the 30 videos were filmed inside the home. A variety of filming techniques were used. Mothers were the main narrators in all but 1 set of videos. The sense of perspectivity was clearly linked to the campaign with the narration pressing home the reality, complexity, and need for vigilance in caring for a child with complex health care needs. Different clinical tasks and routines undertaken as part of the child's care were depicted. Videos also reported on a sense of feeling different than "normal families"; the affect varied among the researchers, ranging from strong to weaker emotional responses.

  2. Is motivation for marathon a protective factor or a risk factor of injury?

    Science.gov (United States)

    Chalabaev, A; Radel, R; Ben Mahmoud, I; Massiera, B; Deroche, T; d'Arripe-Longueville, F

    2017-12-01

    This research investigated whether and how self-determined motivation predicts perceived susceptibility to injury during competition (marathon). Two correlational studies including 378 (Study 1) and 339 (Study 2) marathon runners were conducted. Participants filled out a questionnaire the day before the race measuring self-determined motivation, perceived susceptibilities to marathon-related injury and to keep running through pain, and control variables. Study 1 showed that self-determined motivation was negatively related to perceived susceptibility to marathon-related injury. Study 2 replicated this finding and showed that this relationship was partially mediated by perceived susceptibility to keep running through pain during the race. Moreover, results indicated that the predictive role of self-determination was mostly driven by controlled forms of motivation, and more particularly external regulation. These results suggest that self-determined motivation for sport is a protective factor of injury. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

    NARCIS (Netherlands)

    Kenjeres, S.; Verdoold, J.; Tummers, M.J.; Hanjalic, K.; Kleijn, C.R.

    2009-01-01

    The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is

  4. Motivation for physical activity in children: a moving matter in need for study.

    Science.gov (United States)

    Pannekoek, Linda; Piek, Jan P; Hagger, Martin S

    2013-10-01

    Motivation for physical activity in children below the age of 12 years is a largely underrepresented issue in contemporary research. Although engagement in sufficient physical activity is highly important for children's current and later health, relatively little is known of the factors that motivate children to be physically active. Various theories have been developed in an attempt to explain motivation toward physical activity in adults. Recent developments have focussed on integrating constructs of these theories in order to attain a comprehensive account of motivated behavior. The relationships between different motivational constructs have generally been investigated in healthy adolescents and adults. This manuscript outlines why more theoretically driven research into children's motivation toward physical activity is needed. Constructs stemming from various motivational theories and their interrelationship as evidenced in youth and adults will be summarized. The current state of research on the applicability of these motivational constructs to children, and the generalizability of the interrelationship between the constructs to child samples will be outlined. A deeper insight into the motivational determinants of physical activity participation in children could inform the design of interventions to facilitate the development of physically active lifestyles that persist at older ages. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Beyond good and evil: what motivations underlie children's prosocial behavior?

    Science.gov (United States)

    Martin, Alia; Olson, Kristina R

    2015-03-01

    Researchers have proposed different accounts of the development of prosocial behavior in children. Some have argued that behaviors like helping and sharing must be learned and reinforced; others propose that children have an initially indiscriminate prosocial drive that declines and becomes more selective with age; and yet others contend that even children's earliest prosocial behaviors share some strategic motivations with the prosociality of adults (e.g., reputation enhancement, social affiliation). We review empirical and observational research on children's helping and sharing behaviors in the first 5 years of life, focusing on factors that have been found to influence these behaviors and on what these findings suggest about children's prosocial motivations. We use the adult prosociality literature to highlight parallels and gaps in the literature on the development of prosocial behavior. We address how the evidence reviewed bears on central questions in the developmental psychology literature and propose that children's prosocial behaviors may be driven by multiple motivations not easily captured by the idea of intrinsic or extrinsic motivation and may be selective quite early in life. © The Author(s) 2015.

  6. A qualitative study of uptake of free vitamins in England.

    Science.gov (United States)

    Jessiman, Tricia; Cameron, Ailsa; Wiggins, Meg; Lucas, Patricia J

    2013-08-01

    To identify reasons why eligible families are not accessing free 'Healthy Start' vitamin supplementation (providing vitamins A, C and D) in England. Qualitative study using in-depth interviews. 13 primary care trusts in England. Purposive sample of 15 Healthy Start coordinators, 50 frontline health and children's professionals and 107 parents. Vitamin take-up was low across all research sites, reported as below 10% of eligible beneficiaries for free vitamins. Reasons identified by both parents and professionals included (1) poor accessibility of vitamins, (2) low promotion of the scheme by health professionals, (3) a lack of awareness among eligible families, and (4) low motivation among mothers to take vitamins for themselves during pregnancy or for children under 4 years old. Low uptake rates can be explained by poor accessibility of vitamins and lack of awareness and motivation to take vitamin supplements among eligible families. Universal provision (at least for pregnant women) and better training for health professionals are identified as potential solutions worthy of further research and evaluation.

  7. Perceived medical benefit, peer/partner influence and safety and cost to access the service: client motivators for voluntary seeking of medical male circumcision in Iganga district eastern Uganda, a qualitative study.

    Science.gov (United States)

    Muhamadi, Lubega; Ibrahim, Musenze; Wabwire-Mangen, Fred; Peterson, Stefan; Reynolds, Steven J

    2013-01-01

    Although voluntary medical male circumcision (VMMC) in Iganga district was launched in 2010 as part of the Uganda national strategy to prevent new HIV infections with a target of having 129,896 eligible males circumcised by 2012, only 35,000 (27%) of the anticipated target had been circumcised by mid 2012. There was paucity of information on why uptake of VMMC was low in this setting where HIV awareness is presumably high. This study sought to understand motivators for uptake of VMMC from the perspective of the clients themselves in order to advocate for feasible approaches to expanding uptake of VMMC in Iganga district and similar settings. In Iganga district, we conducted seven key informant interviews with staff who work in the VMMC clinics and twenty in-depth interviews with clients who had accepted and undergone VMMC. Ten focus-group discussions including a total of 112 participants were also conducted with clients who had undergone VMMC. Motivators for uptake of VMMC in the perspective of the circumcised clients and the health care staff included: perceived medical benefit to those circumcised such as protection against acquiring HIV and other sexually transmitted diseases, peer/partner influence, sexual satisfaction and safety and cost to access the service. Since perceived medical benefit was a motivator for seeking VMMC, it can be used to strengthen campaigns for increasing uptake of VMMC. Peer influence could also be used in advocacy campaigns for VMMC expansion, especially using peers who have already undergone VMMC. There is need to ensure that safety and cost to access the service is affordable especially to rural poor as it was mentioned as a motivator for seeking VMMC.

  8. WHAT MOTIVATES CULTURAL TOURISTS? AN ANALYSIS OF BUCHAREST INHABITANTS' MOTIVATION TO VISIT THE CENTRE REGION

    Directory of Open Access Journals (Sweden)

    Ravar Anamaria Sidonia

    2013-07-01

    Full Text Available Cultural tourism is currently one of the main driving forces of the tourist phenomena, accounting for a significant part of the world's tourist flows. Cultural tourism may take many forms, according to the motivation behind tourists' impetus to travel to a certain destination. Cultural heritage and historical sites, dance, music and theatre performances, art galleries, museums and exhibitions, religious and worship sites and ethnic traditions are the main attractions for tourists motivated by knowledge seeking, self-development and the desire to experience other cultures. Although cultural motivations play an important role in the generation of tourist flows towards cultural tourism destinations, a tourism experience is rarely generated as a result of a single motivation. The act of choosing a specific destination and tourism product is influenced by multiple motivations, not only cultural but also connected to relaxation or family. Furthermore, tourism products are rarely homogeneous – a single holiday may include experiences with cultural content as well as leisure time, sports, adventure or entertainment. Thus, culture is not always the main motivation behind cultural tourism and may in fact be less central to the decision to travel than other factors. This is particularly true in the case of destinations which dispose of various cultural assets, but whose natural tourist resources – such as landscape, climate, access to the sea – also makes them attractive for other types of tourism. The aim of this article is to show that in the case of tourist destinations where cultural attractions represent the vast majority of the areas' tourist heritage, cultural motivations remains central to the decision to travel. Furthermore, we will seek to identify the main types of cultural attractions that motivate cultural tourism in Romania by investigating Bucharest inhabitants' perception of the Centre Region, a cultural destination par excellence in

  9. Preliminary Evaluation of the Effectiveness of Air Force Advertising.

    Science.gov (United States)

    Vitola, Bart M.

    The Airman Enlistment Questionnaire was administered to a sample of non prior service enlistees, 1,667 males and 300 females. Analysis of the responses shows (1)educational opportunity is the strongest motivator for enlisting in the Air Force; (2) there is an indication that Air Force advertising should make different appeals to men and women; and…

  10. A systematic review of perceived barriers and motivators to physical activity after stroke.

    Science.gov (United States)

    Nicholson, Sarah; Sniehotta, Falko F; van Wijck, Frederike; Greig, Carolyn A; Johnston, Marie; McMurdo, Marion E T; Dennis, Martin; Mead, Gillian E

    2013-07-01

    Physical fitness is impaired after stroke, may contribute to disability, yet is amenable to improvement through regular physical activity. To facilitate uptake and maintenance of physical activity, it is essential to understand stroke survivors' perceived barriers and motivators. Therefore, we undertook a systematic review of perceived barriers and motivators to physical activity after stroke. Electronic searches of EMBASE, Medline, CINAHL, and PsychInfo were performed. We included peer-reviewed journal articles, in English, between 1 January 1966 and 30 August 2010 reporting stroke survivors' perceived barriers and motivators to physical activity. Searches identified 73,807 citations of which 57 full articles were retrieved. Six articles were included, providing data on 174 stroke survivors (range 10 to 83 per article). Two reported barriers and motivators, two reported only motivators, and two reported only barriers. Five were qualitative articles and one was quantitative. The most commonly reported barriers were lack of motivation, environmental factors (e.g. transport), health concerns, and stroke impairments. The most commonly reported motivators were social support and the need to be able to perform daily tasks. This review has furthered our understanding of the perceived barriers and motivators to physical activity after a stroke. This review will enable the development of tailored interventions to target barriers, while building upon perceived motivators to increase and maintain stroke survivors' physical activity. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

  11. Demotivating incentives and motivation crowding out in charitable giving.

    Science.gov (United States)

    Chao, Matthew

    2017-07-11

    Research has shown that extrinsic incentives can crowd out intrinsic motivation in many contexts. Despite this, many nonprofits offer conditional thank-you gifts, such as mugs or tote bags, in exchange for donations. In collaboration with a nonprofit, this study implements a direct mail field experiment and demonstrates that thank-you gifts reduced donation rates in a fundraising campaign. Attention-based multiattribute choice models suggest that this is because prospective donors shift attention to the salient gift offer, causing them to underweight less salient intrinsic motives. Attention to the gift may also cause individuals to adopt a more cost-benefit mindset, further de-emphasizing intrinsic motives. Consistent with these hypotheses, crowding out was driven by those who donated higher amounts in the previous year (i.e., those who likely had higher intrinsic motivation). In a complementary online experiment, thank-you gifts also reduced donation rates but only when the gift was visually salient. This corroborates the mediating role of attention in crowding out. Taken together, the laboratory and field results demonstrate that this fundraising technique can be demotivating in some contexts and that this may occur through an attention-based mechanism.

  12. Buckling Causes Nonlinear Dynamics of Filamentous Viruses Driven through Nanopores.

    Science.gov (United States)

    McMullen, Angus; de Haan, Hendrick W; Tang, Jay X; Stein, Derek

    2018-02-16

    Measurements and Langevin dynamics simulations of filamentous viruses driven through solid-state nanopores reveal a superlinear rise in the translocation velocity with driving force. The mobility also scales with the length of the virus in a nontrivial way that depends on the force. These dynamics are consequences of the buckling of the leading portion of a virus as it emerges from the nanopore and is put under compressive stress by the viscous forces it encounters. The leading tip of a buckled virus stalls and this reduces the total viscous drag force. We present a scaling theory that connects the solid mechanics to the nonlinear dynamics of polyelectrolytes translocating nanopores.

  13. Implicit and explicit prosocial motivation as antecedents of volunteering : The moderating role of parenthood

    NARCIS (Netherlands)

    Aydinli, A.; Bender, M.; Chasiotis, A.; van de Vijver, F.J.R.; Cemalcilar, Z.

    2015-01-01

    We test a model proposing that having children influences motivational pathways of volunteering in the same way across two different cultures. The model posits that parents’ engagement in volunteering is driven by implicit, whereas non-parents’ engagement in volunteering is related to explicit

  14. Incentivizing around the Globe: Educating for the Challenge of Developing Culturally Considerate Work Motivation Strategies

    Science.gov (United States)

    Mills, Maura J.

    2017-01-01

    Work motivation has long been considered a driving force behind optimal employee management. However, as the workscape continues its path toward increased globalization, today's managers must consider cultural influences on employee motivation to implement the most appropriate human capital management strategies within any given context. The…

  15. Needs Hierarchy, Motivational Factors and Entrepreneurship in Bangladesh

    OpenAIRE

    Mostofa Haque

    2010-01-01

    Every human being is driven by his/her desire to reach his/her needs, whereby the needs evolve to more ambitious needs once the most fundamental needs have been achieved. To reach more ambitious needs, accommodating socio-economic infrastructures and appropriate government support are required. Based on various surveys, this paper examines the needs hierarchy of Bangladeshi people as well as the main hindrances for not reaching higher up needs in Bangladesh. It analyzes the motivational facto...

  16. The influence of extrinsic motivation on competition-based selection.

    Science.gov (United States)

    Sänger, Jessica; Wascher, Edmund

    2011-10-10

    The biased competition approach to visuo-spatial attention proposes that the selection of competing information is effected by the saliency of the stimulus as well as by an intention-based bias of attention towards behavioural goals. Wascher and Beste (2010) [32] showed that the detection of relevant information depends on its relative saliency compared to irrelevant conflicting stimuli. Furthermore the N1pc, N2pc and N2 of the EEG varied with the strength of the conflict. However, this system could also be modulated by rather global mechanisms like attentional effort. The present study investigates such modulations by testing the influence of extrinsic motivation on the selection of competing stimuli. Participants had to detect a luminance change in various conditions among others against an irrelevant orientation change. Half of the participants were motivated to maximize their performance by the announcement of a monetary reward for correct responses. Participants who were motivated had lower error rates than participants who were not motivated. The event-related lateralizations of the EEG showed no motivation-related effect on the N1pc, which reflects the initial saliency driven orientation of attention towards the more salient stimulus. The subsequent N2pc was enhanced in the motivation condition. Extrinsic motivation was also accompanied by enhanced fronto-central negativities. Thus, the data provide evidence that the improvement of selection performance when participants were extrinsically motivated by announcing a reward was not due to changes in the initial saliency based processing of information but was foremost mediated by improved higher-level mechanisms. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Fluorine-labeled Dasatinib Nanoformulations as Targeted Molecular Imaging Probes in a PDGFB-driven Murine Glioblastoma Model

    Directory of Open Access Journals (Sweden)

    Miriam Benezra

    2012-12-01

    Full Text Available Dasatinib, a new-generation Src and platelet-derived growth factor receptor (PDGFR inhibitor, is currently under evaluation in high-grade glioma clinical trials. To achieve optimum physicochemical and/or biologic properties, alternative drug delivery vehicles may be needed. We used a novel fluorinated dasatinib derivative (F-SKI249380, in combination with nanocarrier vehicles and metabolic imaging tools (microPET to evaluate drug delivery and uptake in a platelet-derived growth factor B (PDGFB-driven genetically engineered mouse model (GEMM of high-grade glioma. We assessed dasatinib survival benefit on the basis of measured tumor volumes. Using brain tumor cells derived from PDGFB-driven gliomas, dose-dependent uptake and time-dependent inhibitory effects of F-SKI249380 on biologic activity were investigated and compared with the parent drug. PDGFR receptor status and tumor-specific targeting were non-invasively evaluated in vivo using 18F-SKI249380 and 18F-SKI249380-containing micellar and liposomal nanoformulations. A statistically significant survival benefit was found using dasatinib (95 mg/kg versus saline vehicle (P < .001 in tumor volume-matched GEMM pairs. Competitive binding and treatment assays revealed comparable biologic properties for F-SKI249380 and the parent drug. In vivo, Significantly higher tumor uptake was observed for 18F-SKI249380-containing micelle formulations [4.9 percentage of the injected dose per gram tissue (%ID/g; P = .002] compared to control values (1.6%ID/g. Saturation studies using excess cold dasatinib showed marked reduction of tumor uptake values to levels in normal brain (1.5%ID/g, consistent with in vivo binding specificity. Using 18F-SKI249380-containing micelles as radiotracers to estimate therapeutic dosing requirements, we calculated intratumoral drug concentrations (24–60 nM that were comparable to in vitro 50% inhibitory concentration values. 18F-SKI249380 is a PDGFR-selective tracer, which

  18. Liquid metal actuator driven by electrochemical manipulation of surface tension

    Science.gov (United States)

    Russell, Loren; Wissman, James; Majidi, Carmel

    2017-12-01

    We examine the electrocapillary properties of a fluidic actuator composed of a liquid metal droplet that is submerged in electrolytic solution and attached to an elastic beam. The beam deflection is controlled by electrochemically driven changes in the surface energy of the droplet. The metal is a eutectic gallium-indium alloy that is liquid at room temperature and forms an nm-thin Ga2O3 skin when oxidized. The effective surface tension of the droplet changes dramatically with oxidation and reduction, which are reversibly controlled by applying low voltage to the electrolytic bath. Wetting the droplet to two copper pads allows for a controllable tensile force to be developed between the opposing surfaces. We demonstrate the ability to reliably control force by changing the applied oxidizing voltage. Actuator forces and droplet geometries are also examined by performing a computational fluid mechanics simulation using Surface Evolver. The theoretical predictions are in qualitative agreement with the experimental measurements and provide additional confirmation that actuation is driven by surface tension.

  19. Radial electromagnetic force calculation of induction motor based on multi-loop theory

    Directory of Open Access Journals (Sweden)

    HE Haibo

    2017-12-01

    Full Text Available [Objectives] In order to study the vibration and noise of induction motors, a method of radial electromagnetic force calculation is established on the basis of the multi-loop model.[Methods] Based on the method of calculating air-gap magneto motive force according to stator and rotor fundamental wave current, the analytic formulas are deduced for calculating the air-gap magneto motive force and radial electromagnetic force generated in accordance with any stator winding and rotor conducting bar current. The multi-loop theory and calculation method for the electromagnetic parameters of a motor are introduced, and a dynamic simulation model of an induction motor built to achieve the current of the stator winding and rotor conducting bars, and obtain the calculation formula of radial electromagnetic force. The radial electromagnetic force and vibration are then estimated.[Results] The experimental results indicate that the vibration acceleration frequency and amplitude of the motor are consistent with the experimental results.[Conclusions] The results and calculation method can support the low noise design of converters.

  20. Simulation and Sensitivity in a Nested Modeling System for South America. Part II: GCM Boundary Forcing.

    Science.gov (United States)

    Rojas, Maisa; Seth, Anji

    2003-08-01

    of this study, the RegCM's ability to simulate circulation and rainfall observed in the two extreme seasons was demonstrated when driven at the lateral boundaries by reanalyzed forcing. Seasonal integrations with the RegCM driven by GCM ensemble-derived lateral boundary forcing demonstrate that the nested model responds well to the SST forcing, by capturing the major features of the circulation and rainfall differences between the two years. The GCM-driven model also improves upon the monthly evolution of rainfall compared with that from the GCM. However, the nested model rainfall simulations for the two seasons are degraded compared with those from the reanalyses-driven RegCM integrations. The poor location of the Atlantic intertropical convergence zone (ITCZ) in the GCM leads to excess rainfall in Nordeste in the nested model.An expanded domain was tested, wherein the RegCM was permitted more internal freedom to respond to SST and regional orographic forcing. Results show that the RegCM is able to improve the location of the ITCZ, and the seasonal evolution of rainfall in Nordeste, the Amazon region, and the southeastern region of Brazil. However, it remains that the limiting factor in the skill of the nested modeling system is the quality of the lateral boundary forcing provided by the global model.

  1. Observation and simulation of an optically driven micromotor

    International Nuclear Information System (INIS)

    Metzger, N K; Mazilu, M; Dholakia, K; Kelemen, L; Ormos, P

    2011-01-01

    In the realm of low Reynolds number flow there is a need to find methods to pump, move and mix minute amounts of analyte. Interestingly, micro-devices performing such actuation can be initiated by means of the light–matter interaction. Light induced forces and torques are exerted on such micro-objects, which are then driven by the optical gradient or scattering force. Here, different driving geometries can be realized to harness the light induced force. For example, the scattering force enables micro-gears to be operated in a tangential setup where the micromotor rotors are in line with an optical waveguide. The operational geometry we investigate has the advantage that it reduces the complexity of the driving of such a device in a microfluidic environment by delivering the actuating light by means of a waveguide or fiber optic. In this paper we explore the case of a micromotor being driven by a fiber optically delivered light beam. We experimentally investigate how the driving light interacts with and diffracts from the motor, utilizing two-photon imaging. The micromotor rotation rate dependence on the light field parameters is explored. Additionally, a theoretical model based on the paraxial approximation is used to simulate the torque and predict the rotation rate of such a device and compare it with experiment. The results presented show that our model can be used to optimize the micromotor performance and some example motor designs are evaluated

  2. Observation and simulation of an optically driven micromotor

    Science.gov (United States)

    Metzger, N. K.; Mazilu, M.; Kelemen, L.; Ormos, P.; Dholakia, K.

    2011-04-01

    In the realm of low Reynolds number flow there is a need to find methods to pump, move and mix minute amounts of analyte. Interestingly, micro-devices performing such actuation can be initiated by means of the light-matter interaction. Light induced forces and torques are exerted on such micro-objects, which are then driven by the optical gradient or scattering force. Here, different driving geometries can be realized to harness the light induced force. For example, the scattering force enables micro-gears to be operated in a tangential setup where the micromotor rotors are in line with an optical waveguide. The operational geometry we investigate has the advantage that it reduces the complexity of the driving of such a device in a microfluidic environment by delivering the actuating light by means of a waveguide or fiber optic. In this paper we explore the case of a micromotor being driven by a fiber optically delivered light beam. We experimentally investigate how the driving light interacts with and diffracts from the motor, utilizing two-photon imaging. The micromotor rotation rate dependence on the light field parameters is explored. Additionally, a theoretical model based on the paraxial approximation is used to simulate the torque and predict the rotation rate of such a device and compare it with experiment. The results presented show that our model can be used to optimize the micromotor performance and some example motor designs are evaluated.

  3. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    Science.gov (United States)

    Lu, Yi-Ching; Chang, Fan-Yu; Tu, Shu-Ju; Chen, Jyh-Ping; Ma, Yunn-Hwa

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNPcell) appeared to be magnetic field- and concentration-dependent. In H-field, MNPcell reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNPcell, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNPcell in the L-field may reach as high as 80% of that in H-field during 1-6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNPcell analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo.

  4. Heterogeneous motives in the Trust Game: a Tale of two Roles

    Directory of Open Access Journals (Sweden)

    Antonio M. Espín

    2016-05-01

    Full Text Available AbstractLevels of trust and trustworthiness have important externalities for the society. But what exactly do these social concepts reflect? Building upon the argument that in typical real-life social exchanges people act simultaneously as both trustors and trustees, we study the impact of individuals’ social motives (or preferences on their choices in a dual-role Trust Game (TG. We employ data from a large-scale representative experiment (N = 774, where all subjects played both roles of a binary TG with real monetary incentives. Subjects’ social motives were inferred using their decisions in a Dictator Game and a dual-role Ultimatum Game. Next to self-interest and strategic motives we consider preferences for altruism, spitefulness, egalitarianism and efficiency. We demonstrate that there exists considerable heterogeneity in motives in the TG. Most importantly, among individuals who choose to trust as trustors, social motives can differ dramatically as there is a non-negligible proportion of them who seem to act out of (strategic self-interest whereas others are driven more by efficiency considerations. Subjects’ elicited trustworthiness, however, can be used to infer such motivations: while the former are not trustworthy as trustees, the latter are. We discuss that research on trust can benefit from adding the second player’s choice in TG designs.

  5. Employee commitment and motivation: a conceptual analysis and integrative model.

    Science.gov (United States)

    Myer, John P; Becker, Thomas E; Vandenberghe, Christian

    2004-12-01

    Theorists and researchers interested in employee commitment and motivation have not made optimal use of each other's work. Commitment researchers seldom address the motivational processes through which commitment affects behavior, and motivation researchers have not recognized important distinctions in the forms, foci, and bases of commitment. To encourage greater cross-fertilization, the authors present an integrative framework in which commitment is presented as one of several energizing forces for motivated behavior. E. A. Locke's (1997) model of the work motivation process and J. P. Meyer and L. Herscovitch's (2001) model of workplace commitments serve as the foundation for the development of this new framework. To facilitate the merger, a new concept, goal regulation, is derived from self-determination theory (E. L. Deci & R. M. Ryan, 1985) and regulatory focus theory (E. I. Higgins, 1997). By including goal regulation, it is acknowledged that motivated behavior can be accompanied by different mindsets that have particularly important implications for the explanation and prediction of discretionary work behavior. 2004 APA, all rights reserved

  6. Thyroid uptake test

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    The uptake of radioiodine by the thyroid gland is altered by the iodine content of diet or drugs. American diet has a high iodine content because each slice of the white bread contains nearly 150μg of iodine due to the bleaching process employed in the production of the bread. This carrier content of iodine reduces the uptake so much, that the normal American uptakes are usually three to four times lower than the uptakes in the developing countries. The other drawback of the thyroid uptake test is that it is affected by the iodine containing drugs. Anti-diarrhoea medications are quire common in the developing countries and many of them contain iodine moiety. Without a reliable drug history, a low thyroid uptake value may lead to a misleading conclusion

  7. Motivations for Food Consumption during Specific Eating Occasions in Turkey.

    Science.gov (United States)

    Chambers, Delores; Phan, Uyen T X; Chanadang, Sirichat; Maughan, Curtis; Sanchez, Karolina; Di Donfrancesco, Brizio; Gomez, David; Higa, Federica; Li, Han; Chambers, Edgar; Esen, Eyyup

    2016-05-24

    Several studies in different countries have been conducted to investigate factors affecting food choices. The objective of this study was to understand the motivations of specific food and beverage choices for different eating occasions in a typical diet of the Turkish people. A convenience sample of 141 respondents from seven different geographical regions in Turkey completed an online survey questionnaire that included questions about demographic information and details about their latest eating occasion. Respondents reported all of their motivations for choosing each food/beverage item reported for that specific eating occasion. Results indicated that different motivations played different roles in food choices of people in Turkey. Liking was a key characteristic for all eating occasions, but key natural concerns were even more important at breakfast, and need and hunger were more important for a mid-afternoon snack. Lunch involved additional motivations such as Sociability, Variety Seeking, and Social Norms. In addition to Liking, choices of different food groups were also driven by other motivations such as Habits, Convenience, Need and Hunger, Natural Concerns, and Health. This study helped better understand the current dietary patterns of Turkish people as well as the motives underlying their choices of foods and beverages for different meals and snacks. These findings could be useful for dietary campaigns that aim to improve eating behaviors in Turkey.

  8. Motivations for Food Consumption during Specific Eating Occasions in Turkey

    Directory of Open Access Journals (Sweden)

    Delores Chambers

    2016-05-01

    Full Text Available Several studies in different countries have been conducted to investigate factors affecting food choices. The objective of this study was to understand the motivations of specific food and beverage choices for different eating occasions in a typical diet of the Turkish people. A convenience sample of 141 respondents from seven different geographical regions in Turkey completed an online survey questionnaire that included questions about demographic information and details about their latest eating occasion. Respondents reported all of their motivations for choosing each food/beverage item reported for that specific eating occasion. Results indicated that different motivations played different roles in food choices of people in Turkey. Liking was a key characteristic for all eating occasions, but key natural concerns were even more important at breakfast, and need and hunger were more important for a mid-afternoon snack. Lunch involved additional motivations such as Sociability, Variety Seeking, and Social Norms. In addition to Liking, choices of different food groups were also driven by other motivations such as Habits, Convenience, Need and Hunger, Natural Concerns, and Health. This study helped better understand the current dietary patterns of Turkish people as well as the motives underlying their choices of foods and beverages for different meals and snacks. These findings could be useful for dietary campaigns that aim to improve eating behaviors in Turkey.

  9. Motivations for Food Consumption during Specific Eating Occasions in Turkey

    Science.gov (United States)

    Chambers, Delores; Phan, Uyen T. X.; Chanadang, Sirichat; Maughan, Curtis; Sanchez, Karolina; Di Donfrancesco, Brizio; Gomez, David; Higa, Federica; Li, Han; Chambers, Edgar; Esen, Eyyup

    2016-01-01

    Several studies in different countries have been conducted to investigate factors affecting food choices. The objective of this study was to understand the motivations of specific food and beverage choices for different eating occasions in a typical diet of the Turkish people. A convenience sample of 141 respondents from seven different geographical regions in Turkey completed an online survey questionnaire that included questions about demographic information and details about their latest eating occasion. Respondents reported all of their motivations for choosing each food/beverage item reported for that specific eating occasion. Results indicated that different motivations played different roles in food choices of people in Turkey. Liking was a key characteristic for all eating occasions, but key natural concerns were even more important at breakfast, and need and hunger were more important for a mid-afternoon snack. Lunch involved additional motivations such as Sociability, Variety Seeking, and Social Norms. In addition to Liking, choices of different food groups were also driven by other motivations such as Habits, Convenience, Need and Hunger, Natural Concerns, and Health. This study helped better understand the current dietary patterns of Turkish people as well as the motives underlying their choices of foods and beverages for different meals and snacks. These findings could be useful for dietary campaigns that aim to improve eating behaviors in Turkey. PMID:28231134

  10. The thermodynamic cycle of an entropy-driven stepper motor walking hand-over-hand

    International Nuclear Information System (INIS)

    Zabicki, Michal; Ebeling, Werner; Gudowska-Nowak, Ewa

    2010-01-01

    Graphical abstract: We develop a new model of an entropy-driven stepper motor walking hand-over-hand, coupled to the energy reservoir of ATP. - Abstract: We develop a model of a kinesin motor based on an entropy-driven spring between the two heads of the stepper. The stepper is coupled to the energy depot which is reservoir of ATP. A Langevin equation for the motion of the two legs in a ratchet potential is analyzed by performing numerical simulations. It is documented that the model motor is able to work against a load force with an efficiency of about 10-30%. At a critical load force the motor stops to operate.

  11. Performance of direct-driven flapping-wing actuator with piezoelectric single-crystal PIN-PMN-PT

    Science.gov (United States)

    Ozaki, Takashi; Hamaguchi, Kanae

    2018-02-01

    We present a prototype flapping-wing actuator with a direct-driven mechanism to generate lift in micro- and nano-aerial vehicles. This mechanism has an advantage of simplicity because it has no transmission system between the actuator and wing. We fabricated the piezoelectric unimorph actuator from single-crystal PIN-PMN-PT, which achieved a lift force up to 1.45 mN, a value about 1.9 times larger than the mass of the actuator itself. This is the first reported demonstration of an insect-scale actuator with a direct-driven mechanism that can generate a lift force greater than its own weight.

  12. Investigation of Current Driven Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Agerkvist, Finn T.; Knott, Arnold

    2015-01-01

    Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage an......” woofer where a copper ring in the pole piece has not been implemented to compensate for eddy currents. However the drive method seems to be irrelevant for a 5” woofer where the compliance, force factor as well as the voice coil inductance has been optimized for linearity.......Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage...

  13. The human small intestinal microbiota is driven by rapid uptake and conversion of simple carbohydrates

    DEFF Research Database (Denmark)

    Zoetendal, Erwin G; Raes, Jeroen; van den Bogert, Bartholomeus

    2012-01-01

    in parallel. Comparative functional analysis with fecal metagenomes identified functions that are overrepresented in the small intestine, including simple carbohydrate transport phosphotransferase systems (PTS), central metabolism and biotin production. Moreover, metatranscriptome analysis supported high...... level in-situ expression of PTS and carbohydrate metabolic genes, especially those belonging to Streptococcus sp. Overall, our findings suggest that rapid uptake and fermentation of available carbohydrates contribute to maintaining the microbiota in the human small intestine....

  14. Awareness and uptake of colorectal, breast, cervical and prostate cancer screening tests in Spain.

    Science.gov (United States)

    Carrasco-Garrido, Pilar; Hernandez-Barrera, Valentın; Lopez de Andres, Ana; Jimenez-Trujillo, Isabel; Gallardo Pino, Carmen; Jimenez-Garcıa, Rodrigo

    2014-04-01

    We aim to describe levels of awareness and uptake of colorectal, breast, cervical and prostate cancer screening tests and to analyze the association to socio-demographic and health-related variables. Population-based cross-sectional study conducted using a home-based personal interview survey on a nationwide representative sample (n = 7938) of population aged ≥18 years (Oncobarometro Survey). Awareness was assessed by asking participants: Now I am going to mention several medical tests for cancer detection, please tell me if you already know about them or if this is the first time you have heard of them? The tests mentioned were faecal occult blood test (FOBT), mammography, Pap smear and prostate-specific antigen (PSA). Cancer screening uptake was assessed by asking participants whether they had received tests within the previous 2 years. Awareness rates of 38.55% for FOBT, 95.03% for mammography, 70.84% for Pap smears and 54.72% for PSA were found. Uptake mammography was 74.46%, Pap smears 65.57%, PSA 35.19% and FOBT 9.40%. Factors such as immigration status, lower educational level or income and not suffering from chronic conditions are negative predictors for uptake. Awareness and uptake results showed acceptable figures for mammography, moderate for Pap smears and unacceptably low for FOBT. Inequalities exist in uptake of cancer screening. It is necessary to develop public health educational programmes, especially for the vulnerable populations, aiming to inform and motivate them to use screening services on a regular basis. Our data suggest that although PSA is not recommended, this opportunistic screening is frequently used in Spain.

  15. Travelling solitons in the parametrically driven nonlinear Schroedinger equation

    International Nuclear Information System (INIS)

    Barashenkov, I.V.; Zemlyanaya, E.V.; Baer, M.

    2000-01-01

    We show that the parametrically driven nonlinear Schroedinger equation has wide classes of travelling soliton solutions, some of which are stable. For small driving strengths stable nonpropagating and moving solitons co-exist while strongly forced solitons can only be stable when moving sufficiently fast

  16. MOTIVATION

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Introduction What is the difference between instrumental and integrative motivation? What kind of motivations do students have? How can our knowledge of motivation help the language learning process? Motivation can be very important in language teaching. Students can do very well when they are motivated. Teachers, with their knowledge of motivation, can make their classes more efficient and successful. Middle school teachers, in addition to learning about the English language itself, and about teaching methods, should also learn more about motivation and how this affects our students. "When we consider language teaching, motivation can be classified as either integrative or instrumental motivation" (Luxon)

  17. Quantifying the carbon uptake by vegetation for Europe on a 1 km2 resolution using a remote sensing driven vegetation model

    Science.gov (United States)

    Wißkirchen, K.; Tum, M.; Günther, K. P.; Niklaus, M.; Eisfelder, C.; Knorr, W.

    2013-04-01

    In this study we compare monthly gross primary productivity (GPP) time series (2000-2007), computed for Europe with the Biosphere Energy Transfer Hydrology (BETHY/DLR) model with monthly data from the eddy covariance measurements network FLUXNET. BETHY/DLR with a spatial resolution of 1 km2 is designed for regional and continental applications (here Europe) and operated at the German Aerospace Center (DLR). It was adapted from the BETHY scheme to be driven by remote sensing data and meteorology. Time series of Leaf Area Index (LAI) are used to control the development of vegetation. These are taken from the CYCLOPES database. Meteorological time series are used to regulate meteorological seasonality. These comprise daily information on temperature, precipitation, wind-speed and radiation. Additionally, static maps such as land cover, elevation, and soil type are used. To validate our model results we used eddy covariance measurements from the FLUXNET network of 74 towers across Europe. For forest sites we found that our model predicts between 20% and 40% higher annual GPP sums. In contrast, for cropland sites BETHY/DLR results show about 18% less GPP than eddy covariance measurements. For grassland sites, between 10% more and 16% less GPP was calculated with BETHY/DLR. A mean total carbon uptake of 2.5 Pg C yr-1 (±0.17 Pg) was found for Europe. In addition, this study states on risks that arise from the comparison of modeled data to FLUXNET measurements and their interpretation width.

  18. Quantification of tension to explain bias dependence of driven polymer translocation dynamics

    Science.gov (United States)

    Suhonen, P. M.; Piili, J.; Linna, R. P.

    2017-12-01

    Motivated by identifying the origin of the bias dependence of tension propagation, we investigate methods for measuring tension propagation quantitatively in computer simulations of driven polymer translocation. Here, the motion of flexible polymer chains through a narrow pore is simulated using Langevin dynamics. We measure tension forces, bead velocities, bead distances, and bond angles along the polymer at all stages of translocation with unprecedented precision. Measurements are done at a standard temperature used in simulations and at zero temperature to pin down the effect of fluctuations. The measured quantities were found to give qualitatively similar characteristics, but the bias dependence could be determined only using tension force. We find that in the scaling relation τ ˜Nβfdα for translocation time τ , the polymer length N , and the bias force fd, the increase of the exponent β with bias is caused by center-of-mass diffusion of the polymer toward the pore on the cis side. We find that this diffusion also causes the exponent α to deviate from the ideal value -1 . The bias dependence of β was found to result from combination of diffusion and pore friction and so be relevant for polymers that are too short to be considered asymptotically long. The effect is relevant in experiments all of which are made using polymers whose lengths are far below the asymptotic limit. Thereby, our results also corroborate the theoretical prediction by Sakaue's theory [Polymers 8, 424 (2016), 10.3390/polym8120424] that there should not be bias dependence of β for asymptotically long polymers. By excluding fluctuations we also show that monomer crowding at the pore exit cannot have a measurable effect on translocation dynamics under realistic conditions.

  19. Changes in calcium uptake rate by rat cardiac mitochondria during postnatal development.

    Science.gov (United States)

    Bassani, R A; Fagian, M M; Bassani, J W; Vercesi, A E

    1998-10-01

    Ca2+ uptake, transmembrane electrical potential (Deltapsim) and oxygen consumption were measured in isolated ventricular mitochondria of rats from 3 days to 5 months of age. Estimated values of ruthenium red-sensitive, succinate-supported maximal rate of Ca2+ uptake (Vmax, expressed as nmol Ca2+/min/mg protein) were higher in neonates and gradually fell during postnatal development (from 435+/-24 at 3-6 days, to 156+/-10 in adults,Palpha-ketoglutarate as substrates) and state 3ADP (alpha-ketoglutarate-supported) respiration rates, as well as Deltapsim values (approximately-150 mV). Respiration-independent Deltapsim and Ca2+ uptake, supported by valinomycin-induced K+ efflux were also investigated at these ages. A transient Deltapsim (approximately -30 mV) was evoked by valinomycin in both neonatal and adult mitochondria. Respiration-independent Ca2+ uptake was also transient, but its initial rate was significantly higher in neonates than in adults (49. 4+/-10.0v 28.0+/-5.7 mmol Ca2+/min/mg protein,P<0.01). These results indicate that Ca2+ uptake capacity of rat cardiac mitochondria is remarkably high just after birth and declines over the first weeks of postnatal life, without change in apparent affinity of the transporter. Increased mitochondrial Ca2+ uptake rate in neonates appears to be related to the uniporter itself, rather than to modification of the driving force of the transport. Copyright 1998 Academic Press

  20. Hope and Anxiety in Physics Class: Exploring Their Motivational Antecedents and Influence on Metacognition and Performance

    Science.gov (United States)

    González, Antonio; Fernández, María-Victoria Carrera; Paoloni, Paola-Verónica

    2017-01-01

    Recent research on achievement in science asserts that motivation, emotion, and metacognition are important driving forces for learning. This study sought to examine the relationships between two physics class emotions (hope and anxiety), their motivational predictors (instrumentality and self-efficacy), and their effects on metacognitive problem…

  1. Pressure-driven ballistic Kelvin's water dropper for energy harvesting

    NARCIS (Netherlands)

    Xie, Yanbo; de Boer, Hans L.; van den Berg, Albert; Sprenkels, A.J.; Eijkel, Jan C.T.

    2014-01-01

    In this paper, we introduce a microfluidic-based self-excited energy conversion system inspired by Kelvin's water dropper but driven by inertia instead of gravity. Two micro water jets are produced by forcing water through two micropores by overpressure. The jets break up into microdroplets which

  2. Stability and instability of axisymmetric droplets in thermocapillary-driven thin films

    Science.gov (United States)

    Nicolaou, Zachary G.

    2018-03-01

    The stability of compactly supported, axisymmetric droplet states is considered for driven thin viscous films evolving on two-dimensional surfaces. Stability is assessed using Lyapunov energy methods afforded by the Cahn-Hilliard variational form of the governing equation. For general driving forces, a criterion on the gradient of profiles at the boundary of their support (their contact slope) is shown to be a necessary condition for stability. Additional necessary and sufficient conditions for stability are established for a specific driving force corresponding to a thermocapillary-driven film. It is found that only droplets of sufficiently short height that satisfy the contact slope criterion are stable. This destabilization of droplets with increasing height is characterized as a saddle-node bifurcation between a branch of tall, unstable droplets and a branch of short, stable droplets.

  3. Hybrid Force Control Based on ICMAC for an Astronaut Rehabilitative Training Robot

    Directory of Open Access Journals (Sweden)

    Lixun Zhang

    2012-08-01

    Full Text Available A novel Astronaut Rehabilitative Training Robot (ART based on a cable-driven mechanism is represented in this paper. ART, a typical passive force servo system, can help astronauts to bench press in a microgravity environment. The purpose of this paper is to design controllers to eliminate the surplus force caused by an astronaut's active movements. Based on the dynamics modelling of the cable-driven unit, a hybrid force controller based on improved credit assignment CMAC (ICMAC is presented. A planning method for the cable tension is proposed so that the dynamic load produced by the ART can realistically simulate the gravity and inertial force of the barbell in a gravity environment. Finally, MATLAB simulation results of the man-machine cooperation system are provided in order to verify the effectiveness of the proposed control strategy. The simulation results show that the hybrid control method based on the structure invariance principle can inhibit the surplus force and that ICMAC can improve the dynamic performance of the passive force servo system. Furthermore, the hybrid force controller based on ICMAC can ensure the stability of the system.

  4. The Stiffness Variation of a Micro-Ring Driven by a Traveling Piecewise-Electrode

    Directory of Open Access Journals (Sweden)

    Yingjie Li

    2014-09-01

    Full Text Available In the practice of electrostatically actuated micro devices; the electrostatic force is implemented by sequentially actuated piecewise-electrodes which result in a traveling distributed electrostatic force. However; such force was modeled as a traveling concentrated electrostatic force in literatures. This article; for the first time; presents an analytical study on the stiffness variation of microstructures driven by a traveling piecewise electrode. The analytical model is based on the theory of shallow shell and uniform electrical field. The traveling electrode not only applies electrostatic force on the circular-ring but also alters its dynamical characteristics via the negative electrostatic stiffness. It is known that; when a structure is subjected to a traveling constant force; its natural mode will be resonated as the traveling speed approaches certain critical speeds; and each natural mode refers to exactly one critical speed. However; for the case of a traveling electrostatic force; the number of critical speeds is more than that of the natural modes. This is due to the fact that the traveling electrostatic force makes the resonant frequencies of the forward and backward traveling waves of the circular-ring different. Furthermore; the resonance and stability can be independently controlled by the length of the traveling electrode; though the driving voltage and traveling speed of the electrostatic force alter the dynamics and stabilities of microstructures. This paper extends the fundamental insights into the electromechanical behavior of microstructures driven by electrostatic forces as well as the future development of MEMS/NEMS devices with electrostatic actuation and sensing.

  5. A photon-driven micromotor can direct nerve fibre growth

    Science.gov (United States)

    Wu, Tao; Nieminen, Timo A.; Mohanty, Samarendra; Miotke, Jill; Meyer, Ronald L.; Rubinsztein-Dunlop, Halina; Berns, Michael W.

    2012-01-01

    Axonal path-finding is important in the development of the nervous system, nerve repair and nerve regeneration. The behaviour of the growth cone at the tip of the growing axon determines the direction of axonal growth and migration. We have developed an optical-based system to control the direction of growth of individual axons (nerve fibres) using laser-driven spinning birefringent spheres. One or two optical traps position birefringent beads adjacent to growth cones of cultured goldfish retinal ganglion cell axons. Circularly polarized light with angular momentum causes the trapped bead to spin. This creates a localized microfluidic flow generating an estimated 0.17 pN shear force against the growth cone that turns in response to the shear. The direction of axonal growth can be precisely manipulated by changing the rotation direction and position of this optically driven micromotor. A physical model estimating the shear force density on the axon is described.

  6. Optimized Free Energies from Bidirectional Single-Molecule Force Spectroscopy

    Science.gov (United States)

    Minh, David D. L.; Adib, Artur B.

    2008-05-01

    An optimized method for estimating path-ensemble averages using data from processes driven in opposite directions is presented. Based on this estimator, bidirectional expressions for reconstructing free energies and potentials of mean force from single-molecule force spectroscopy—valid for biasing potentials of arbitrary stiffness—are developed. Numerical simulations on a model potential indicate that these methods perform better than unidirectional strategies.

  7. Diet-induced obesity: dopamine transporter function, impulsivity and motivation.

    Science.gov (United States)

    Narayanaswami, V; Thompson, A C; Cassis, L A; Bardo, M T; Dwoskin, L P

    2013-08-01

    A rat model of diet-induced obesity (DIO) was used to determine dopamine transporter (DAT) function, impulsivity and motivation as neurobehavioral outcomes and predictors of obesity. To evaluate neurobehavioral alterations following the development of DIO induced by an 8-week high-fat diet (HF) exposure, striatal D2-receptor density, DAT function and expression, extracellular dopamine concentrations, impulsivity, and motivation for high- and low-fat reinforcers were determined. To determine predictors of DIO, neurobehavioral antecedents including impulsivity, motivation for high-fat reinforcers, DAT function and extracellular dopamine were evaluated before the 8-week HF exposure. Striatal D2-receptor density was determined by in vitro kinetic analysis of [(3)H]raclopride binding. DAT function was determined using in vitro kinetic analysis of [(3)H]dopamine uptake, methamphetamine-evoked [(3)H]dopamine overflow and no-net flux in vivo microdialysis. DAT cell-surface expression was determined using biotinylation and western blotting. Impulsivity and food-motivated behavior were determined using a delay discounting task and progressive ratio schedule, respectively. Relative to obesity-resistant (OR) rats, obesity-prone (OP) rats exhibited 18% greater body weight following an 8-week HF-diet exposure, 42% lower striatal D2-receptor density, 30% lower total DAT expression, 40% lower in vitro and in vivo DAT function, 45% greater extracellular dopamine and twofold greater methamphetamine-evoked [(3)H]dopamine overflow. OP rats exhibited higher motivation for food, and surprisingly, were less impulsive relative to OR rats. Impulsivity, in vivo DAT function and extracellular dopamine concentration did not predict DIO. Importantly, motivation for high-fat reinforcers predicted the development of DIO. Human studies are limited by their ability to determine if impulsivity, motivation and DAT function are causes or consequences of DIO. The current animal model shows that

  8. Plant uptake of dual-labeled organic N biased by inorganic C uptake

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Sauheitl, Leopold; Eriksen, Jørgen

    2010-01-01

    glycine or CO2-3 , but found no differences in uptake rates between these C-sources. The uptake of inorganic C to the shoot tissue was higher for maize grown in full light compared to shading, which indicates a passive uptake of inorganic C with water. We conclude that uptake of inorganic C produced...

  9. In Search of Motivation for the Business Survey Response Task

    NARCIS (Netherlands)

    Torres van Grinsven, Vanessa; Bolko, Irena; Bavdaz, Mojca

    2014-01-01

    Increasing reluctance of businesses to participate in surveys often leads to declining or low response rates, poor data quality and burden complaints, and suggests that a driving force, that is, the motivation for participation and accurate and timely response, is insufficient or lacking.

  10. Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil

    Science.gov (United States)

    Murguia-Flores, Fabiola; Arndt, Sandra; Ganesan, Anita L.; Murray-Tortarolo, Guillermo; Hornibrook, Edward R. C.

    2018-06-01

    Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4), a potent greenhouse gas that is responsible for ˜ 20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of factors, including temperature, soil texture, moisture and nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability, remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0) to simulate and quantify the uptake of atmospheric CH4 by soils at the global scale. MeMo builds on previous models by Ridgwell et al. (1999) and Curry (2007) by introducing several advances, including (1) a general analytical solution of the one-dimensional diffusion-reaction equation in porous media, (2) a refined representation of nitrogen inhibition on soil methanotrophy, (3) updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates and (4) the ability to evaluate the impact of autochthonous soil CH4 sources on uptake of atmospheric CH4. We show that the improved structural and parametric representation of key drivers of soil methanotrophy in MeMo results in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990-2009 using MeMo yielded an average annual sink of 33.5 ± 0.6 Tg CH4 yr-1. Warm and semi-arid regions (tropical deciduous forest and open shrubland) had the highest CH4 uptake rates of 602 and 518 mg CH4 m-2 yr-1, respectively. In these regions, favourable annual soil moisture content ( ˜ 20 % saturation) and low seasonal temperature variations (variations < ˜ 6 °C) provided optimal conditions for soil methanotrophy and soil-atmosphere gas exchange. In contrast to previous model analyses, but in agreement with recent observational data

  11. Pedestrian-induced lateral forces on footbridges

    DEFF Research Database (Denmark)

    Ingolfsson, Einar Thor; Georgakis, Christos T.; Jönsson, Jeppe

    2012-01-01

    of the underlying pavement. An extensive experimental analysis has been carried out to determine the lateral forces generated by pedestrians when walking on a laterally moving treadmill. Two different conditions are investigated; initially the treadmill is fixed and then it is laterally driven in a sinusoidal...... motion at varying combinations of frequencies (0.33-1.07 Hz) and amplitudes (4.5-48 mm). The component of the pedestrian-induced force which is caused by the laterally moving surface is herewith quantified through equivalent velocity and acceleration proportional coefficients. It is shown that large...

  12. Pedestrian-induced lateral forces on footbridges

    DEFF Research Database (Denmark)

    Ingólfsson, Einar Thór; Georgakis, Christos T.; Jönsson, Jeppe

    2011-01-01

    of the underlying pavement. An extensive experimental analysis has been carried out to determine the lateral forces generated by pedestrians when walking on a laterally moving treadmill. Two different conditions are investigated; initially the treadmill is fixed and then it is laterally driven in a sinusoidal...... motion at varying combinations of frequencies (0.33-1.07 Hz) and amplitudes (4.5-48 mm). The component of the pedestrian-induced force which is caused by the laterally moving surface is herewith quantified through equivalent velocity and acceleration proportional coefficients. It is shown that large...

  13. From chemolithoautotrophs to electrolithoautotrophs: CO2 fixation by Fe(II)-oxidizing bacteria coupled with direct uptake of electrons from solid electron sources.

    Science.gov (United States)

    Ishii, Takumi; Kawaichi, Satoshi; Nakagawa, Hirotaka; Hashimoto, Kazuhito; Nakamura, Ryuhei

    2015-01-01

    At deep-sea vent systems, hydrothermal emissions rich in reductive chemicals replace solar energy as fuels to support microbial carbon assimilation. Until recently, all the microbial components at vent systems have been assumed to be fostered by the primary production of chemolithoautotrophs; however, both the laboratory and on-site studies demonstrated electrical current generation at vent systems and have suggested that a portion of microbial carbon assimilation is stimulated by the direct uptake of electrons from electrically conductive minerals. Here we show that chemolithoautotrophic Fe(II)-oxidizing bacterium, Acidithiobacillus ferrooxidans, switches the electron source for carbon assimilation from diffusible Fe(2+) ions to an electrode under the condition that electrical current is the only source of energy and electrons. Site-specific marking of a cytochrome aa3 complex (aa3 complex) and a cytochrome bc1 complex (bc1 complex) in viable cells demonstrated that the electrons taken directly from an electrode are used for O2 reduction via a down-hill pathway, which generates proton motive force that is used for pushing the electrons to NAD(+) through a bc1 complex. Activation of carbon dioxide fixation by a direct electron uptake was also confirmed by the clear potential dependency of cell growth. These results reveal a previously unknown bioenergetic versatility of Fe(II)-oxidizing bacteria to use solid electron sources and will help with understanding carbon assimilation of microbial components living in electronically conductive chimney habitats.

  14. Curvature recognition and force generation in phagocytosis

    Directory of Open Access Journals (Sweden)

    Prassler Jana

    2010-12-01

    Full Text Available Abstract Background The uptake of particles by actin-powered invagination of the plasma membrane is common to protozoa and to phagocytes involved in the immune response of higher organisms. The question addressed here is how a phagocyte may use geometric cues to optimize force generation for the uptake of a particle. We survey mechanisms that enable a phagocyte to remodel actin organization in response to particles of complex shape. Results Using particles that consist of two lobes separated by a neck, we found that Dictyostelium cells transmit signals concerning the curvature of a surface to the actin system underlying the plasma membrane. Force applied to a concave region can divide a particle in two, allowing engulfment of the portion first encountered. The phagosome membrane that is bent around the concave region is marked by a protein containing an inverse Bin-Amphiphysin-Rvs (I-BAR domain in combination with an Src homology (SH3 domain, similar to mammalian insulin receptor tyrosine kinase substrate p53. Regulatory proteins enable the phagocyte to switch activities within seconds in response to particle shape. Ras, an inducer of actin polymerization, is activated along the cup surface. Coronin, which limits the lifetime of actin structures, is reversibly recruited to the cup, reflecting a program of actin depolymerization. The various forms of myosin-I are candidate motor proteins for force generation in particle uptake, whereas myosin-II is engaged only in retracting a phagocytic cup after a switch to particle release. Thus, the constriction of a phagocytic cup differs from the contraction of a cleavage furrow in mitosis. Conclusions Phagocytes scan a particle surface for convex and concave regions. By modulating the spatiotemporal pattern of actin organization, they are capable of switching between different modes of interaction with a particle, either arresting at a concave region and applying force in an attempt to sever the particle

  15. Models of misbelief: Integrating motivational and deficit theories of delusions.

    Science.gov (United States)

    McKay, Ryan; Langdon, Robyn; Coltheart, Max

    2007-12-01

    The impact of our desires and preferences upon our ordinary, everyday beliefs is well-documented [Gilovich, T. (1991). How we know what isn't so: The fallibility of human reason in everyday life. New York: The Free Press.]. The influence of such motivational factors on delusions, which are instances of pathological misbelief, has tended however to be neglected by certain prevailing models of delusion formation and maintenance. This paper explores a distinction between two general classes of theoretical explanation for delusions; the motivational and the deficit. Motivational approaches view delusions as extreme instances of self-deception; as defensive attempts to relieve pain and distress. Deficit approaches, in contrast, view delusions as the consequence of defects in the normal functioning of belief mechanisms, underpinned by neuroanatomical or neurophysiological abnormalities. It is argued that although there are good reasons to be sceptical of motivational theories (particularly in their more floridly psychodynamic manifestations), recent experiments confirm that motives are important causal forces where delusions are concerned. It is therefore concluded that the most comprehensive account of delusions will involve a theoretical unification of both motivational and deficit approaches.

  16. Lattice Boltzmann simulations of attenuation-driven acoustic streaming

    International Nuclear Information System (INIS)

    Haydock, David; Yeomans, J M

    2003-01-01

    We show that lattice Boltzmann simulations can be used to model the attenuation-driven acoustic streaming produced by a travelling wave. Comparisons are made to analytical results and to the streaming pattern produced by an imposed body force approximating the Reynolds stresses. We predict the streaming patterns around a porous material in an attenuating acoustic field

  17. Motivation of Czech Employees by the Balanced Scorecard of the Multinational Company – an Empirical Study

    OpenAIRE

    Janasová, Barbora

    2013-01-01

    The aim of this paper is to review if the implemented balanced scorecard is an efficient way to motivate people and increase their work effort. The empirical research had been conducted in one of the big multinational companies. Balanced scorecards for such companies are mainly driven by global, strategic measures. It is questionable, if employees of the Czech local branch are interested and motivated by the global results. Perhaps, it would make more sense to put emphasis on the individual p...

  18. On transition from Alfvén resonance to forced magnetic reconnection

    International Nuclear Information System (INIS)

    Luan, Q.; Wang, X.

    2014-01-01

    We revisit the transition from Alfvén resonance to forced magnetic reconnection with a focus on the property of their singularities. As the driven frequency tends to zero, the logarithmic singularity of Alfvén resonance shifts to the power-law singularity of forced reconnection, due to merging of the two resonance layers. The transition criterion depends on either kinetic effects or dissipations that resolve the singularity. As an example, a small but finite resistivity η is introduced to investigate the transition process. The transition threshold is then obtained as the driven frequency reaches a level of ∼O((η/k) 1/3 )

  19. Rubber friction and force transmission during the shearing process of actively-driven vacuum grippers on rough surfaces

    International Nuclear Information System (INIS)

    Kern, Patrick

    2016-01-01

    Nowadays, vacuum grippers come in many different shapes and sizes. Their stability is guaranteed through specially manufactured metal fittings. These fittings are non-positively and positively connected to the elastic part of the vacuum gripper. The design of the elastic part may vary, though. Elastomer components are used to ensure tightness for the negative pressure in the active cave chamber of the vacuum gripper, as well as for the transfer of shearing forces, which acting parallel to the surface. Some vacuum grippers feature one elastomer for both the sealing function and the transfer of shear forces; other gripper types are equipped with various elastomers for those applications. The vacuum grippers described in this work are equipped with structured rubber friction pads, their tightness being ensured by sealing lips made of a flexible foam rubber. A restraint system consisting of one or several vacuum grippers must be sized prior to its actual practical use. For the transmission of shearing forces, which acting parallel to the surface, it is necessary to take the tribological system, consisting of the suction element's elastomer and the base material, into account since these loads put shearing stress on the vacuum gripper. In practice, however, a standardized value is given for the coefficient of friction μ; i.e. the ratio of transmissible frictional force to the normal force. This does neither include a detailed description of the elastomer used nor of the roughness of the base material. The standardized friction coefficients cannot be applied to the practical design of restraint systems. The present work includes the analysis of the load transmission and the modeling of the friction coefficients μ on rough surfaces during the shearing process of actively-driven vacuum grippers. Based on current theories, the phenomenon of elastomeric friction can be attributed to the two main components of hysteresis and adhesion friction. Both components are presented

  20. Female labor force participation in developing countries

    OpenAIRE

    Verick, Sher

    2014-01-01

    While women’s labor force participation tends to increase with economic development, the relationship is not straightforward or consistent at the country level. There is considerably more variation across developing countries in labor force participation by women than by men. This variation is driven by a wide variety of economic and social factors, which include economic growth, education, and social norms. Looking more broadly at improving women’s access to quality employment, a critica...

  1. Molecular dynamics for irradiation driven chemistry: application to the FEBID process*

    Science.gov (United States)

    Sushko, Gennady B.; Solov'yov, Ilia A.; Solov'yov, Andrey V.

    2016-10-01

    A new molecular dynamics (MD) approach for computer simulations of irradiation driven chemical transformations of complex molecular systems is suggested. The approach is based on the fact that irradiation induced quantum transformations can often be treated as random, fast and local processes involving small molecules or molecular fragments. We advocate that the quantum transformations, such as molecular bond breaks, creation and annihilation of dangling bonds, electronic charge redistributions, changes in molecular topologies, etc., could be incorporated locally into the molecular force fields that describe the classical MD of complex molecular systems under irradiation. The proposed irradiation driven molecular dynamics (IDMD) methodology is designed for the molecular level description of the irradiation driven chemistry. The IDMD approach is implemented into the MBN Explorer software package capable to operate with a large library of classical potentials, many-body force fields and their combinations. IDMD opens a broad range of possibilities for modelling of irradiation driven modifications and chemistry of complex molecular systems ranging from radiotherapy cancer treatments to the modern technologies such as focused electron beam deposition (FEBID). As an example, the new methodology is applied for studying the irradiation driven chemistry caused by FEBID of tungsten hexacarbonyl W(CO)6 precursor molecules on a hydroxylated SiO2 surface. It is demonstrated that knowing the interaction parameters for the fragments of the molecular system arising in the course of irradiation one can reproduce reasonably well experimental observations and make predictions about the morphology and molecular composition of nanostructures that emerge on the surface during the FEBID process.

  2. Charting the Course for a New Air Force Inspection System

    Science.gov (United States)

    2013-01-01

    perfor- mance. With respect to motivation, the Air Force leadership can, in principle , motivate per- formance within a wing by (1) emphasizing some...turnover. 5 These patterns are compatible with the predictions of a microeconomic model of the quality of the governance of one local organizational...parts of the governance struc- ture display all the scale and substitution effects one would expect in a standard, well-behaved microeconomic production

  3. Comparison of driven and simulated "free" stall flutter in a wind tunnel

    Science.gov (United States)

    Culler, Ethan; Farnsworth, John; Fagley, Casey; Seidel, Jurgen

    2016-11-01

    Stall flutter and dynamic stall have received a significant amount of attention over the years. To experimentally study this problem, the body undergoing stall flutter is typically driven at a characteristic, single frequency sinusoid with a prescribed pitching amplitude and mean angle of attack offset. This approach allows for testing with repeatable kinematics, however it effectively decouples the structural motion from the aerodynamic forcing. Recent results suggest that this driven approach could misrepresent the forcing observed in a "free" stall flutter scenario. Specifically, a dynamically pitched rigid NACA 0018 wing section was tested in the wind tunnel under two modes of operation: (1) Cyber-Physical where "free" stall flutter was physically simulated through a custom motor-control system modeling a torsional spring and (2) Direct Motor-Driven Dynamic Pitch at a single frequency sinusoid representative of the cyber-physical motion. The time-resolved pitch angle and moment were directly measured and compared for each case. It was found that small deviations in the pitch angle trajectory between these two operational cases generate significantly different aerodynamic pitching moments on the wing section, with the pitching moments nearly 180o out of phase in some cases. This work is supported by the Air Force Office of Scientific Research through the Flow Interactions and Control Program and by the National Defense Science and Engineering Graduate Fellowship Program.

  4. The effect of partner HIV status on motivation to take antiretroviral and isoniazid preventive therapies: a conjoint analysis.

    Science.gov (United States)

    Kim, Hae-Young; Hanrahan, Colleen F; Dowdy, David W; Martinson, Neil; Golub, Jonathan; Bridges, John F P

    2018-03-29

    Antiretroviral therapy (ART) and isoniazid preventive therapy (IPT) are important to reduce morbidity and mortality among people newly diagnosed of HIV. The successful uptake of ART and IPT requires a comprehensive understanding of patients' motivation to take such therapies. Partners also play an important role in the decision to be initiated and retained in care. We quantified patients' motivation to take preventive therapies (ART and IPT) and compared by partner HIV status among people newly diagnosed of HIV. We enrolled and surveyed adults (≥18 years) with a recent HIV diagnosis (ART and 334 (79%) had a partner or spouse. Keeping themselves healthy for their family was the most important motivator to take preventive therapies (p motivation for ART and IPT initiation and adherence compared to individual health benefits. These messages should be emphasized to provide effective patient-centered care and counseling.

  5. Resonant difference-frequency atomic force ultrasonic microscope

    Science.gov (United States)

    Cantrell, John H. (Inventor); Cantrell, Sean A. (Inventor)

    2010-01-01

    A scanning probe microscope and methodology called resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), employs an ultrasonic wave launched from the bottom of a sample while the cantilever of an atomic force microscope, driven at a frequency differing from the ultrasonic frequency by one of the contact resonance frequencies of the cantilever, engages the sample top surface. The nonlinear mixing of the oscillating cantilever and the ultrasonic wave in the region defined by the cantilever tip-sample surface interaction force generates difference-frequency oscillations at the cantilever contact resonance. The resonance-enhanced difference-frequency signals are used to create images of nanoscale near-surface and subsurface features.

  6. Motivation of medical students: selection by motivation or motivation by selection.

    Science.gov (United States)

    Wouters, Anouk; Croiset, Gerda; Galindo-Garre, Francisca; Kusurkar, Rashmi A

    2016-01-29

    Medical schools try to implement selection procedures that will allow them to select the most motivated students for their programs. Though there is a general feeling that selection stimulates student motivation, conclusive evidence for this is lacking. The current study aims to use the perspective of Self-determination Theory (SDT) of motivation as a lens to examine how medical students' motivation differs in relation to different selection procedures. The hypotheses were that 1) selected students report higher strength and autonomous motivation than non-selected students, and 2) recently selected students report higher strength and autonomous motivation than non-selected students and students who were selected longer ago. First- (Y1) and fourth-year (Y4) medical students in the six-year regular programme and first-year students in the four-year graduate entry programme (GE) completed questionnaires measuring motivation strength and type (autonomous-AM, controlled-CM). Scores were compared between students admitted based on selection, lottery or top pre-university GPA (top GPA) using ANCOVAs. Selected students' answers on open-ended questions were analysed using inductive thematic analysis to identify reasons for changes in motivation. The response rate was 61.4 % (n = 357). Selected students (Y1, Y4 and GE) reported a significantly higher strength of motivation than non-selected students (Y1 and Y4 lottery and top GPA) (p motivation as they felt autonomous, competent and that they belonged to a special group. These reported reasons are in alignment with the basic psychological needs described by Self-Determination Theory as important in enhancing autonomous motivation. A comprehensive selection procedure, compared to less demanding admission procedures, does not seem to yield a student population which stands out in terms of autonomous motivation. The current findings indicate that selection might temporarily enhance students' motivation. The mechanism

  7. Nonlinear dynamics of a parametrically driven sine-Gordon system

    DEFF Research Database (Denmark)

    Grønbech-Jensen, Niels; Kivshar, Yuri S.; Samuelsen, Mogens Rugholm

    1993-01-01

    We consider a sine-Gordon system, driven by an ac parametric force in the presence of loss. It is demonstrated that a breather can be maintained in a steady state at half of the external frequency. In the small-amplitude limit the effect is described by an effective nonlinear Schrodinger equation...

  8. Flexural Behavior of GFRP Tubes Filled with Magnetically Driven Concrete.

    Science.gov (United States)

    Xie, Fang; Chen, Ju; Dong, Xinlong; Feng, Bing

    2018-01-08

    Experimental investigation of GFRP (glass fiber reinforced polymer) tubes that were filled with magnetically driven concrete was carried out to study the flexural behavior of specimens under bending. Specimens having different cross section and lengths were tested. The test specimens were fabricated by filling magnetically driven concrete into the GFRP tubes and the concrete was vibrated using magnetic force. Specimens vibrated using vibrating tube were also tested for comparison. In addition, specimens having steel reinforcing bars and GFRP bars were both tested to study the effect of reinforcing bars on the magnetically driven concrete. The load-displacement curves, load-strain curves, failure mode, and ultimate strengths of test specimens were obtained. Design methods for the flexural stiffness of test specimens were also discussed in this study.

  9. Lactococcins : Mode of action, immunity and secretion

    NARCIS (Netherlands)

    Venema, K; Kok, J; Venema, Gerhardus

    1995-01-01

    Lactococcus lactis subsp. cremoris 9B4 produces three small (around 5kDa), heat-stable, non-lanthionine containing, membrane active bacteriocins. Amino acid uptake experiments and proton motive force measurements have indicated that these peptides most probably form pores in the cytoplasmic membrane

  10. Iodide uptake by negatively charged clay interlayers?

    International Nuclear Information System (INIS)

    Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

    2015-01-01

    Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI (aq) ) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. - Highlights: • Iodide sorption experiments were completed with a diverse array of clay minerals. • Iodide uptake trended with CEC and swamping electrolyte identity and concentration. • Results can be explained by considering the formation of ion pairs in clay interlayers

  11. An international comparison of stakeholder motivation to implement liver cancer control.

    Science.gov (United States)

    Bridges, John F P; Joy, Susan M; Blauvelt, Barri M; Yan, Weili; Marsteller, Jill A

    2015-06-01

    The World Health Organization offers clear guidance on the development of national cancer control programmes based on a country's level of resources, yet the motivation to implement such programmes may be driven by factors other than resources. To compare stakeholder motivation to implement a national liver cancer control programme and assess if variation in motivation was associated with stakeholder characteristics or with national indicators of need and resources. Relevant stakeholders were purposively selected from 13 countries (Australia, China, France, Germany, Italy, Japan, Nigeria, South Korea, Spain, Taiwan, Thailand, Turkey and USA) to participate in a structured survey on liver cancer control. Respondents included 12 individuals working in clinical, 5 in policy and 3 in advocacy roles from each country. Stakeholders' motivation was measured using a scale grounded in expectancy theory and knowledge gained during previous qualitative interviews. Comparisons across countries and respondent characteristics were conducted using hierarchical regression. Country level motivation scores, holding constant individual level covariates, were correlated with indicators of need and resources and tested using Pearson's correlation coefficients. In total, 260 stakeholders, equally drawn from the study countries, completed the survey (45% response rate). At the national level, motivation was highest in Nigeria, Thailand and China (P motivation was observed among stakeholders working at the international level relative to the local level (P = 0.017). Motivation was positively associated with a country's relative burden of liver cancer (P = 0.015) and negatively associated with their level of resources (P = 0.018). This study provides the first empirical evidence on the motivation of stakeholders to implement national cancer control programmes. Furthermore, we demonstrate that motivation is more clearly associated with a country's cancer control needs rather than resources

  12. Current and Future Decadal Trends in the Oceanic Carbon Uptake Are Dominated by Internal Variability

    Science.gov (United States)

    Li, Hongmei; Ilyina, Tatiana

    2018-01-01

    We investigate the internal decadal variability of the ocean carbon uptake using 100 ensemble simulations based on the Max Planck Institute Earth system model (MPI-ESM). We find that on decadal time scales, internal variability (ensemble spread) is as large as the forced temporal variability (ensemble mean), and the largest internal variability is found in major carbon sink regions, that is, the 50-65°S band of the Southern Ocean, the North Pacific, and the North Atlantic. The MPI-ESM ensemble produces both positive and negative 10 year trends in the ocean carbon uptake in agreement with observational estimates. Negative decadal trends are projected to occur in the future under RCP4.5 scenario. Due to the large internal variability, the Southern Ocean and the North Pacific require the most ensemble members (more than 53 and 46, respectively) to reproduce the forced decadal trends. This number increases up to 79 in future decades as CO2 emission trajectory changes.

  13. Heat driven pulse pump

    Science.gov (United States)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  14. Determination of maximum physiologic thyroid uptake and correlation with 24-hour RAI uptake value

    International Nuclear Information System (INIS)

    Duldulao, M.; Obaldo, J.

    2007-01-01

    Full text: In hyperthyroid patients, thyroid uptake values are overestimated, sometimes approaching or exceeding 100%. This is physiologically and mathematically impossible. This study was undertaken to determine the maximum physiologic thyroid uptake value through a proposed simple method using a gamma camera. Methodology: Twenty-two patients (17 females and 5 males), with ages ranging from 19-61 y/o (mean age ± SD; 41 ± 12), with 24-hour uptake value of >50%, clinically hyperthyroid and referred for subsequent radioactive iodine therapy were studied. The computed maximum physiologic thyroid uptake was compared with the 24-hour uptake using the paired Student t-test and evaluated using linear regression analysis. Results: The computed physiologic uptake correlated poorly with the 24-hour uptake value. However, in the male subgroup, there was no statistically significant difference between the two (p=0.77). Linear regression analysis gives the following relationship: physiologic uptake (%) = 77.76 - 0.284 (24-hour RAI uptake value). Conclusion: Provided that proper regions of interest are applied with correct attenuation and background subtraction, determination of physiologic thyroid uptake may be obtained using the proposed method. This simple method may be useful prior to I-131 therapy for hyperthyroidism especially when a single uptake determination is performed. (author)

  15. Relations between OCBs, organizational justice, work motivation and self-efficacy

    Directory of Open Access Journals (Sweden)

    Lior Oren

    2013-06-01

    Full Text Available The importance of organizational citizenship behaviors (OCBs in organizations is well documented, and studies that originate from the interactionist perspective and combine personal and situational factors in predicting OCBs are needed. Toward this end, and based on a recent theoretical model, the current study attempted to predict OCB by organizational justice, work motivation, and self-efficacy. A research questionnaire measuring the three predictors was administered to 151 employees, and a measure of their OCB was provided by their supervisors. Whereas OCBs were found to be positively correlated with the three predictors, a hierarchical regression analysis revealed that only organizational justice and work motivation were significant predictors of OCBs. The study emphasizes the importance of using an interactionist perspective integrating endogenous and exogenous forces in studying the antecedents of OCBs. OCBs may be closely related to task performance and may be predicted by motivation related variables. Organizations may facilitate OCBs by improving organizational justice and raising work motivation among employees.

  16. Investigation of a mutual interaction force at different pressure amplitudes in sulfuric acid

    International Nuclear Information System (INIS)

    Rezaee, Nastaran; Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Ebrahimi, Homa

    2011-01-01

    This paper investigates the secondary Bjerknes force for two oscillating bubbles in various pressure amplitudes in a concentration of 95% sulfuric acid. The equilibrium radii of the bubbles are assumed to be smaller than 10 μm at a frequency of 37 kHz in various strong driving acoustical fields around 2.0 bars (1 bar=10 5 Pa). The secondary Bjerknes force is investigated in uncoupled and coupled states between the bubbles, with regard to the quasi-adiabatic model for the bubble interior. It finds that the value of the secondary Bjerknes force depends on the driven pressure of sulfuric acid and its amount would be increased by liquid pressure amplitude enhancement. The results show that the repulsion area of the interaction force would be increased by increasing the driven pressure because of nonlinear oscillation of bubbles. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  17. Domestic uptake of green energy promoted by opt-out tariffs

    Science.gov (United States)

    Ebeling, Felix; Lotz, Sebastian

    2015-09-01

    Motivating individuals to choose energy from sustainable sources over conventionally produced power constitutes one of the biggest policy challenges for societies. Here we present the results of a randomized controlled trial in Germany that tested the impact of default rules (that is, a type of `nudging’) on voluntary purchases of `green’ energy contracts that entirely stem from renewable resources. Setting the default choice to more expensive `green’ energy (that is, where consumers have to actively opt out if they do not want it) increased purchases of such nearly tenfold. Furthermore, county-level political preference for the green party uniquely predicted behaviour in the absence of the nudge, suggesting that default setting potentially overrules motivational aspects of green energy purchases. In follow-up experiments, we provide further evidence that the effect does not seem to be driven by unawareness. Summarizing, the present research provides an example of using behavioural science for climate change mitigation and shows alternatives to the use of subsidies or other economic incentives.

  18. A simple model of the effect of ocean ventilation on ocean heat uptake

    Science.gov (United States)

    Nadiga, Balu; Urban, Nathan

    2017-11-01

    Transport of water from the surface mixed layer into the ocean interior is achieved, in large part, by the process of ventilation-a process associated with outcropping isopycnals. Starting from such a configuration of outcropping isopycnals, we derive a simple model of the effect of ventilation on ocean uptake of anomalous radiative forcing. This model can be seen as an improvement of the popular anomaly-diffusing class of energy balance models (AD-EBM) that are routinely employed to analyze and emulate the warming response of both observed and simulated Earth system. We demonstrate that neither multi-layer, nor continuous-diffusion AD-EBM variants can properly represent both surface-warming and the vertical distribution of ocean heat uptake. The new model overcomes this deficiency. The simplicity of the models notwithstanding, the analysis presented and the necessity of the modification is indicative of the role played by processes related to the down-welling branch of global ocean circulation in shaping the vertical distribution of ocean heat uptake.

  19. Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape.

    Science.gov (United States)

    Fest, Benedikt; Wardlaw, Tim; Livesley, Stephen J; Duff, Thomas J; Arndt, Stefan K

    2015-11-01

    Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions, mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance, we observed a decrease in soil CH4 uptake. A similar age dependency of potential CH4 oxidation for three soil layers (0.0-0.05, 0.05-0.10, 0.10-0.15 m) could be observed on incubated soils under controlled laboratory conditions. The differences in soil CH4 uptake between forest stands of different age were predominantly driven by differences in soil moisture status, which affected the diffusion of atmospheric CH4 into the soil. The observed soil moisture pattern was likely driven by changes in interception or evapotranspiration with forest age, which have been well described for similar eucalypt forest systems in south-eastern Australia. Our results imply that there is a large amount of variability in CH4 uptake at a landscape scale that can be attributed to stand age and soil moisture differences. An increase in severe WF frequency in response to climate change could potentially increase overall forest soil CH4 sinks. © 2015 John Wiley & Sons Ltd.

  20. External Hand Forces Exerted by Long-Term Care Staff to Push Floor-Based Lifts: Effects of Flooring System and Resident Weight.

    Science.gov (United States)

    Lachance, Chantelle C; Korall, Alexandra M B; Russell, Colin M; Feldman, Fabio; Robinovitch, Stephen N; Mackey, Dawn C

    2016-09-01

    The aim of this study was to investigate the effects of flooring type and resident weight on external hand forces required to push floor-based lifts in long-term care (LTC). Novel compliant flooring is designed to reduce fall-related injuries among LTC residents but may increase forces required for staff to perform pushing tasks. A motorized lift may offset the effect of flooring on push forces. Fourteen female LTC staff performed straight-line pushes with two floor-based lifts (conventional, motor driven) loaded with passengers of average and 90th-percentile resident weights over four flooring systems (concrete+vinyl, compliant+vinyl, concrete+carpet, compliant+carpet). Initial and sustained push forces were measured by a handlebar-mounted triaxial load cell and compared to participant-specific tolerance limits. Participants rated pushing difficulty. Novel compliant flooring increased initial and sustained push forces and subjective ratings compared to concrete flooring. Compared to the conventional lift, the motor-driven lift substantially reduced initial and sustained push forces and perceived difficulty of pushing for all four floors and both resident weights. Participants exerted forces above published tolerance limits only when using the conventional lift on the carpet conditions (concrete+carpet, compliant+carpet). With the motor-driven lift only, resident weight did not affect push forces. Novel compliant flooring increased linear push forces generated by LTC staff using floor-based lifts, but forces did not exceed tolerance limits when pushing over compliant+vinyl. The motor-driven lift substantially reduced push forces compared to the conventional lift. Results may help to address risk of work-related musculoskeletal injury, especially in locations with novel compliant flooring. © 2016, Human Factors and Ergonomics Society.

  1. Large-scale neural networks and the lateralization of motivation and emotion.

    Science.gov (United States)

    Tops, Mattie; Quirin, Markus; Boksem, Maarten A S; Koole, Sander L

    2017-09-01

    Several lines of research in animals and humans converge on the distinction between two basic large-scale brain networks of self-regulation, giving rise to predictive and reactive control systems (PARCS). Predictive (internally-driven) and reactive (externally-guided) control are supported by dorsal versus ventral corticolimbic systems, respectively. Based on extant empirical evidence, we demonstrate how the PARCS produce frontal laterality effects in emotion and motivation. In addition, we explain how this framework gives rise to individual differences in appraising and coping with challenges. PARCS theory integrates separate fields of research, such as research on the motivational correlates of affect, EEG frontal alpha power asymmetry and implicit affective priming effects on cardiovascular indicators of effort during cognitive task performance. Across these different paradigms, converging evidence points to a qualitative motivational division between, on the one hand, angry and happy emotions, and, on the other hand, sad and fearful emotions. PARCS suggests that those two pairs of emotions are associated with predictive and reactive control, respectively. PARCS theory may thus generate important new insights on the motivational and emotional dynamics that drive autonomic and homeostatic control processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Small tourism accommodation business owners in Ghana: a factor analysis of motivations and challenges

    Directory of Open Access Journals (Sweden)

    J Mensah-Ansah

    2014-01-01

    Full Text Available Five hundred and five small tourism accommodation business owners in Ghana were surveyed to determine their motivation for owning/operating a small tourism business and the challenges they encounter. Tourism accommodation business owners indicated factors such as maintaining lifestyle, being their own bosses, capitalising on a business opportunity, generation of retirement income influence the decision to own/operate a small tourism accommodation businesses. These variables can be categorized as non-economic and economic factors. It was found that though the owners were motivated by commercial enterprise goals, these are subordinated to the pursuit of socially driven lifestyle motivation factors. Small tourism accommodation business owners in Ghana perceive the non-availability of skilled hospitality personnel and limited access to structured hospitality training programmes as the greatest challenge facing their industry.

  3. Carbonate-sensitive phytotransferrin controls high-affinity iron uptake in diatoms

    Science.gov (United States)

    McQuaid, Jeffrey B.; Kustka, Adam B.; Oborník, Miroslav; Horák, Aleš; McCrow, John P.; Karas, Bogumil J.; Zheng, Hong; Kindeberg, Theodor; Andersson, Andreas J.; Barbeau, Katherine A.; Allen, Andrew E.

    2018-03-01

    In vast areas of the ocean, the scarcity of iron controls the growth and productivity of phytoplankton. Although most dissolved iron in the marine environment is complexed with organic molecules, picomolar amounts of labile inorganic iron species (labile iron) are maintained within the euphotic zone and serve as an important source of iron for eukaryotic phytoplankton and particularly for diatoms. Genome-enabled studies of labile iron utilization by diatoms have previously revealed novel iron-responsive transcripts, including the ferric iron-concentrating protein ISIP2A, but the mechanism behind the acquisition of picomolar labile iron remains unknown. Here we show that ISIP2A is a phytotransferrin that independently and convergently evolved carbonate ion-coordinated ferric iron binding. Deletion of ISIP2A disrupts high-affinity iron uptake in the diatom Phaeodactylum tricornutum, and uptake is restored by complementation with human transferrin. ISIP2A is internalized by endocytosis, and manipulation of the seawater carbonic acid system reveals a second-order dependence on the concentrations of labile iron and carbonate ions. In P. tricornutum, the synergistic interaction of labile iron and carbonate ions occurs at environmentally relevant concentrations, revealing that carbonate availability co-limits iron uptake. Phytotransferrin sequences have a broad taxonomic distribution and are abundant in marine environmental genomic datasets, suggesting that acidification-driven declines in the concentration of seawater carbonate ions will have a negative effect on this globally important eukaryotic iron acquisition mechanism.

  4. Partial purification of the ATP-driven calcium pump of Streptococcus sanguis

    International Nuclear Information System (INIS)

    Lynn, A.R.; Rosen, B.P.

    1986-01-01

    ATP-dependent transport of calcium has been observed in several species of streptococci as uptake of 45 Ca 2+ into everted membrane vesicles. Membranes from Streptococcus sanguis and Streptococcus faecalis were solubilized with octyl-β-D-glucoside or Triton X-100, and the extracts reconstituted into proteoliposomes containing Escherichia coli or soybean phospholipid. Calcium transport in reconstituted proteoliposomes was insensitive to the ionophores nigericin and valinomycin and was unaffected by the F 0 F 1 inhibitor N,N'-dicyclohexylcarbodiimide. Uptake was inhibited by ortho-vanadate with a K/sub i/ in the micromolar range. These results demonstrate that the reconstituted transport activities are not the result of ATP-driven proton pumping via the F 0 F 1 coupled to a calcium/proton antiporter and suggest that existence of a calcium translocating ATPase. Partial purification of the transport activity from Streptococcus sanguis has been achieved using density gradient centrifugation and FPLC

  5. Measuring motivation in schizophrenia: Is a general state of motivation necessary for task-specific motivation?

    Science.gov (United States)

    Choi, Jimmy; Choi, Kee-Hong; Reddy, Felice; Fiszdon, Joanna M.

    2014-01-01

    Despite the important role of motivation in rehabilitation and functional outcomes in schizophrenia, to date, there has been little emphasis on how motivation is assessed. This is important, since different measures may tap potentially discrete motivational constructs, which in turn may have very different associations to important outcomes. In the current study, we used baseline data from 71 schizophrenia spectrum outpatients enrolled in a rehabilitation program to examine the relationship between task-specific motivation, as measured by the Intrinsic Motivation Inventory (IMI), and a more general state of volition/initiation, as measured by the three item Quality of Life (QLS) motivation index. We also examined the relationship of these motivation measures to demographic, clinical and functional variables relevant to rehabilitation outcomes. The two motivation measures were not correlated, and participants with low general state motivation exhibited a full range of task-specific motivation. Only the QLS motivation index correlated with variables relevant to rehabilitation outcomes. The lack of associations between QLS motivation index and IMI subscales suggests that constructs tapped by these measures may be divergent in schizophrenia, and specifically that task-specific intrinsic motivation is not contingent on a general state of motivation. That is, even in individuals with a general low motivational state (i.e. amotivation), interventions aimed at increasing task-specific motivation may still be effective. Moreover, the pattern of interrelationships between the QLS motivation index and variables relevant to psychosocial rehabilitation supports its use in treatment outcome studies. PMID:24529609

  6. Field Tests to Investigate the Penetration Rate of Piles Driven by Vibratory Installation

    Directory of Open Access Journals (Sweden)

    Zhaohui Qin

    2017-01-01

    Full Text Available Factors directly affecting the penetration rate of piles installed by vibratory driving technique are summarized and classified into seven aspects which are driving force, resistance, vibratory amplitude, energy consumption, speeding up at the beginning, pile plumbness keeping, and slowing down at the end, from the mechanism and engineering practice of the vibratory pile driving. In order to find out how these factors affect the penetration rate of the pile in three major actors of vibratory pile driving: (i the pile to be driven, (ii the selected driving system, and (iii the imposed soil conditions, field tests on steel sheet piles driven by vibratory driving technique in different soil conditions are conducted. The penetration rates of three different sheet pile types having up to four different lengths installed using two different vibratory driving systems are documented. Piles with different lengths and types driven with or without clutch have different penetration rates. The working parameters of vibratory hammer, such as driving force and vibratory amplitude, have great influences on the penetration rate of the pile, especially at the later stages of the sinking process. Penetration rate of piles driven in different soil conditions is uniform because of the different penetration resistance including shaft friction and toe resistance.

  7. Phase transformations and systems driven far from equilibrium

    International Nuclear Information System (INIS)

    Ma, E.; Atzmon, M.; Bellon, P.; Trivedi, R.

    1998-01-01

    This volume compiles invited and contributed papers that were presented at Symposium B of the 1997 Materials Research Society Fall Meeting, Phase Transformations and Systems Driven Far From Equilibrium, which was held December 1--5, in Boston, Massachusetts. While this symposium followed the tradition of previous MRS symposia on the fundamental topic of phase transformations, this year the emphasis was on materials systems driven far from equilibrium. The central theme of the majority of the work presented is the understanding of the thermodynamics and kinetics of phase transformations, with significant coverage of metastable materials and externally forced transformations driven, for example, by energy beams or mechanical deformation. The papers are arranged in seven sections: solidification theory and experiments; nucleation; solid state transformations and microstructural evolution; beam-induced transformations; amorphous solids; interfacial and thin film transformations; and nanophases and mechanical alloying. One hundred three papers have been processed separately for inclusion on the data base

  8. Utilization of a Model for Uptake of Cadmium by Plants as a Phytoremediation Assessment Tool

    Science.gov (United States)

    Takahashi, M.; Furbish, D. J.; Clarke, J.

    2008-12-01

    Some traditional methods of environmental remediation, such as removal and disposal of contaminated soil, are loosing economic favor and public acceptance, while others, such as in situ phytoremediation, are being carefully examined because of their attractiveness as environmentally friendly, low-cost solutions to site clean-up. The success of phytoremediation strategies, however, hinges on the ability of selected plants, or plant communities, to effectively uptake, accumulate and tolerate targeted contaminants. Heavy metals, specifically cadmium (Cd), are not essential nutrients to plants. However, chemically similar zinc (Zn) is a micronutrient and is actively taken up by hyperaccumulators. For this reason, the mechanisms involved in uptake of Cd parallel those of Zn. Ideally, Cd would be allocated to the stem, leaf, and/or flower, where it becomes harvestable. Our modeling work simulates the uptake and the storage of Cd in a growing hyperaccumulator. After uptake, Cd is partitioned between adsorption to plant tissue and upward movement to leaves driven by transpiration. Uptake, adsorption and transport are also regulated by phytotoxicity. Simulations suggest that a young plant with small biomass can quickly reach phytotoxicity, which shuts down the normal operation of the plant. Conversely, mature plants on a mildly contaminated site, if harvested before the plants die due to phytotoxicity or natural cause, not only survive but may occasionally thrive. The immediate aim is to estimate the effectiveness and limitations of Cd uptake by hyperaccumulators. The eventual goal of this study is to expand the model in spatial and temporal scales, from individual plants to the community scale, and from one harvest interval to several generations. Understanding the interface between physical and biological processes, specifically the uptake and release of contaminants, provides scientists and engineers tools to assess whether phytoremediation is a reasonable strategy for a

  9. Microgravity Investigation of Capillary Driven Imbibition

    Science.gov (United States)

    Dushin, V. R.; Nikitin, V. F.; Smirnov, N. N.; Skryleva, E. I.; Tyurenkova, V. V.

    2018-05-01

    The goal of the present paper is to investigate the capillary driven filtration in porous media under microgravity conditions. New mathematical model that allows taking into account the blurring of the front due to the instability of the displacement that is developing at the front is proposed. The constants in the mathematical model were selected on the basis of the experimental data on imbibition into unsaturated porous media under microgravity conditions. The flow under the action of a combination of capillary forces and a constant pressure drop or a constant flux is considered. The effect of capillary forces and the type of wettability of the medium on the displacement process is studied. A criterion in which case the capillary effects are insignificant and can be neglected is established.

  10. Motivated prediction of future feelings: effects of negative mood and mood orientation on affective forecasts.

    Science.gov (United States)

    Buehler, Roger; McFarland, Cathy; Spyropoulos, Vassili; Lam, Kent C H

    2007-09-01

    This article examines the role of motivational factors in affective forecasting. The primary hypothesis was that people predict positive emotional reactions to future events when they are motivated to enhance their current feelings. Three experiments manipulated participants' moods (negative vs. neutral) and orientation toward their moods (reflective vs. ruminative) and then assessed the positivity of their affective predictions for future events. As hypothesized, when participants adopted a reflective orientation, and thus should have been motivated to engage in mood-regulation processes, they predicted more positive feelings in the negative than in the neutral mood condition. This pattern of mood-incongruent affective prediction was not exhibited when participants adopted a ruminative orientation. Additionally, within the negative mood condition, generating affective forecasts had a more positive emotional impact on reflectors than on ruminators. The findings suggest that affective predictions are sometimes driven by mood-regulatory motives.

  11. Supercritical CO2 uptake by nonswelling phyllosilicates.

    Science.gov (United States)

    Wan, Jiamin; Tokunaga, Tetsu K; Ashby, Paul D; Kim, Yongman; Voltolini, Marco; Gilbert, Benjamin; DePaolo, Donald J

    2018-01-30

    Interactions between supercritical (sc) CO 2 and minerals are important when CO 2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO 2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO 2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubation with scCO 2 ), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO 2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO 2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO 2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO 2 , can increase CO 2 storage capacity by up to ∼30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO 2 uptake constitutes a previously unrecognized potential trapping mechanism. Copyright © 2018 the Author(s). Published by PNAS.

  12. Driven Quantum Dynamics: Will It Blend?

    Directory of Open Access Journals (Sweden)

    Leonardo Banchi

    2017-10-01

    Full Text Available Randomness is an essential tool in many disciplines of modern sciences, such as cryptography, black hole physics, random matrix theory, and Monte Carlo sampling. In quantum systems, random operations can be obtained via random circuits thanks to so-called q-designs and play a central role in condensed-matter physics and in the fast scrambling conjecture for black holes. Here, we consider a more physically motivated way of generating random evolutions by exploiting the many-body dynamics of a quantum system driven with stochastic external pulses. We combine techniques from quantum control, open quantum systems, and exactly solvable models (via the Bethe ansatz to generate Haar-uniform random operations in driven many-body systems. We show that any fully controllable system converges to a unitary q-design in the long-time limit. Moreover, we study the convergence time of a driven spin chain by mapping its random evolution into a semigroup with an integrable Liouvillian and finding its gap. Remarkably, we find via Bethe-ansatz techniques that the gap is independent of q. We use mean-field techniques to argue that this property may be typical for other controllable systems, although we explicitly construct counterexamples via symmetry-breaking arguments to show that this is not always the case. Our findings open up new physical methods to transform classical randomness into quantum randomness, via a combination of quantum many-body dynamics and random driving.

  13. Community-based evaluation of PMTCT uptake in Nyanza Province, Kenya.

    Directory of Open Access Journals (Sweden)

    Pamela K Kohler

    Full Text Available Facility-based assessments of prevention of mother-to-child HIV transmission (PMTCT programs may overestimate population coverage. There are few community-based studies that evaluate PMTCT coverage and uptake.During 2011, a cross-sectional community survey among women who gave birth in the prior year was performed using the KEMRI-CDC Health and Demographic Surveillance System in Western Kenya. A random sample (n = 405 and a sample of women known to be HIV-positive through previous home-based testing (n = 247 were enrolled. Rates and correlates of uptake of antenatal care (ANC, HIV-testing, and antiretrovirals (ARVs were determined.Among 405 women in the random sample, 379 (94% reported accessing ANC, most of whom (87% were HIV tested. Uptake of HIV testing was associated with employment, higher socioeconomic status, and partner HIV testing. Among 247 known HIV-positive women, 173 (70% self-disclosed their HIV status. Among 216 self-reported HIV-positive women (including 43 from the random sample, 82% took PMTCT ARVs, with 54% completing the full antenatal, peripartum, and postpartum course. Maternal ARV use was associated with more ANC visits and having an HIV tested partner. ARV use during delivery was lowest (62% and associated with facility delivery. Eighty percent of HIV infected women reported having their infant HIV tested, 11% of whom reported their child was HIV infected, 76% uninfected, 6% declined to say, 7% did not recall; 79% of infected children were reportedly receiving HIV care and treatment.Community-based assessments provide data that complements clinic-based PMTCT evaluations. In this survey, antenatal HIV test uptake was high; most HIV infected women received ARVs, though many women did not self-disclose HIV status to field team. Community-driven strategies that encourage early ANC, partner involvement, and skilled delivery, and provide PMTCT education, may facilitate further reductions in vertical transmission.

  14. Understanding the link between older volunteers’ resources and motivation to volunteer

    NARCIS (Netherlands)

    Principi, Andrea; Schippers, Joop; Naegele, Gerd; Di Rosa, Mirko; Lamura, Giovanni

    2016-01-01

    The purpose of this study was to investigate the impact of older volunteers’ available human, social, and cultural capital on their motivational forces to volunteer, measured through the Volunteer Function Inventory. A large European database of 955 older volunteers (i.e., aged 50+) was employed,

  15. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

    Science.gov (United States)

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

    2013-01-01

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

  16. Motivation.

    Science.gov (United States)

    Chambers, David W

    2007-01-01

    Motivation is short-term focused energy. The oldest theories of motivation explain motivated activity as effort to overcome primary deficiencies, such as hunger or boredom. Such theories are difficult to apply because individuals learn idiosyncratic secondary motives as alternative ways of responding to these needs. Three prominent needs theories are discussed: Herzberg's theory of hygiene and motivational factors; McClelland's needs for achievement, power, and affiliation; and Maslow's hierarchy and theory of self-actualization. A second approach to motivation holds that individuals may be thought of as engaging in rational processes to maximize their self-interests. The presented examples of this approach include Vroom's expectancy theory, Adam's theory of inequality, and the Porter-Lawler model that addresses the question of whether satisfaction leads to high performance or vice versa. Finally, several theories of motivation as life orientation are developed.

  17. Limited effects of exogenous glucose during severe hypoxia and a lack of hypoxia-stimulated glucose uptake in isolated rainbow trout cardiac muscle

    Science.gov (United States)

    Becker, Tracy A.; DellaValle, Brian; Gesser, Hans; Rodnick, Kenneth J.

    2013-01-01

    SUMMARY We examined whether exogenous glucose affects contractile performance of electrically paced ventricle strips from rainbow trout under conditions known to alter cardiomyocyte performance, ion regulation and energy demands. Physiological levels of d-glucose did not influence twitch force development for aerobic preparations (1) paced at 0.5 or 1.1 Hz, (2) at 15 or 23°C, (3) receiving adrenergic stimulation or (4) during reoxygenation with or without adrenaline after severe hypoxia. Contractile responses to ryanodine, an inhibitor of Ca2+ release from the sarcoplasmic reticulum, were also not affected by exogenous glucose. However, glucose did attenuate the fall in twitch force during severe hypoxia. Glucose uptake was assayed in non-contracting ventricle strips using 2-[3H] deoxy-d-glucose (2-DG) under aerobic and hypoxic conditions, at different incubation temperatures and with different inhibitors. Based upon a lack of saturation of 2-DG uptake and incomplete inhibition of uptake by cytochalasin B and d-glucose, 2-DG uptake was mediated by a combination of facilitated transport and simple diffusion. Hypoxia stimulated lactate efflux sixfold to sevenfold with glucose present, but did not increase 2-DG uptake or reduce lactate efflux in the presence of cytochalasin B. Increasing temperature (14 to 24°C) also did not increase 2-DG uptake, but decreasing temperature (14 to 4°C) reduced 2-DG uptake by 45%. In conclusion, exogenous glucose improves mechanical performance under hypoxia but not under any of the aerobic conditions applied. The extracellular concentration of glucose and cold temperature appear to determine and limit cardiomyocyte glucose uptake, respectively, and together may help define a metabolic strategy that relies predominantly on intracellular energy stores. PMID:23685969

  18. Motives of enterprises’ expansion abroad during the global financial and economic crisis

    Directory of Open Access Journals (Sweden)

    Joanna Bednarz

    2010-12-01

    Full Text Available The need for facing up the competitors and the wish to build the competitive advantage on the market contribute to enterprises’ expansion on foreign markets. Motives lying behind the enterprise management decision when starting expansion abroad vary and they depend on an individual market situation of the enterprise. They can also evolve in time. The decision about enterprise expansion may be dictated by the will to make advantage of chances which appear on the market. Nevertheless, it also happens that adverse conditions of the enterprise external environment force its internationalization. Motives of foreign expansion can be classified in many ways. This article describes four main groups of motives: market, costs-related, supplies and strategic ones. The second part of this paper analyses changes in enterprises’ motives of expansion during the global financial and economic crisis.

  19. Combined photothermal therapy and magneto-motive ultrasound imaging using multifunctional nanoparticles

    Science.gov (United States)

    Mehrmohammadi, Mohammad; Ma, Li L.; Chen, Yun-Sheng; Qu, Min; Joshi, Pratixa; Chen, Raeanna M.; Johnston, Keith P.; Emelianov, Stanislav

    2010-02-01

    Photothermal therapy is a laser-based non-invasive technique for cancer treatment. Photothermal therapy can be enhanced by employing metal nanoparticles that absorb the radiant energy from the laser leading to localized thermal damages. Targeting of nanoparticles leads to more efficient uptake and localization of photoabsorbers thus increasing the effectiveness of the treatment. Moreover, efficient targeting can reduce the required dosage of photoabsorbers; thereby reducing the side effects associated with general systematic administration of nanoparticles. Magnetic nanoparticles, due to their small size and response to an external magnetic field gradient have been proposed for targeted drug delivery. In this study, we investigate the applicability of multifunctional nanoparticles (e.g., magneto-plasmonic nanoparticles) and magneto-motive ultrasound imaging for image-guided photothermal therapy. Magneto-motive ultrasound imaging is an ultrasound based imaging technique capable of detecting magnetic nanoparticles indirectly by utilizing a high strength magnetic field to induce motion within the magnetically labeled tissue. The ultrasound imaging is used to detect the internal tissue motion. Due to presence of the magnetic component, the proposed multifunctional nanoparticles along with magneto-motive ultrasound imaging can be used to detect the presence of the photo absorbers. Clearly the higher concentration of magnetic carriers leads to a monotonic increase in magneto-motive ultrasound signal. Thus, magnetomotive ultrasound can determine the presence of the hybrid agents and provide information about their location and concentration. Furthermore, the magneto-motive ultrasound signal can indicate the change in tissue elasticity - a parameter that is expected to change significantly during the photothermal therapy. Therefore, a comprehensive guidance and assessment of the photothermal therapy may be feasible through magneto-motive ultrasound imaging and

  20. Electric current-driven migration of electrically neutral particles in liquids

    International Nuclear Information System (INIS)

    Zhang, Xinfang; Qin, Rongshan

    2014-01-01

    We design and experimentally demonstrate a migration of electrically neutral particles in liquids driven by electric current according to the discrepancies of their electrical conductivities. A force from electric current to electrically neutral particles has been identified to drive the particles toward the lateral surface from the centre of suspension via three distinguishable zones, namely, pushing, trapping, and expelling zones. The driving force can overtake gravity in practical cases. The property of the force is found neither similar to that of the force in electromagnetophoresis nor similar to that of the electromigration force in terms of direction and magnitude. An expression for the force at the pushing zone has been developed based on the numerical calculation of the thermodynamics of suspension fluids. The excellent agreement between numerical calculations and experimental data demonstrates that our calculation provides fundamental and predictive insight into particles separation from the liquids. Therefore, it is possible to use the force in many engineering applications such as separation of particles according to the differences of their electrical conductivities

  1. Soil Methanotrophy Model (MeMo v1.0: a process-based model to quantify global uptake of atmospheric methane by soil

    Directory of Open Access Journals (Sweden)

    F. Murguia-Flores

    2018-06-01

    Full Text Available Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4, a potent greenhouse gas that is responsible for  ∼  20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of factors, including temperature, soil texture, moisture and nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability, remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0 to simulate and quantify the uptake of atmospheric CH4 by soils at the global scale. MeMo builds on previous models by Ridgwell et al. (1999 and Curry (2007 by introducing several advances, including (1 a general analytical solution of the one-dimensional diffusion–reaction equation in porous media, (2 a refined representation of nitrogen inhibition on soil methanotrophy, (3 updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates and (4 the ability to evaluate the impact of autochthonous soil CH4 sources on uptake of atmospheric CH4. We show that the improved structural and parametric representation of key drivers of soil methanotrophy in MeMo results in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990–2009 using MeMo yielded an average annual sink of 33.5 ± 0.6 Tg CH4 yr−1. Warm and semi-arid regions (tropical deciduous forest and open shrubland had the highest CH4 uptake rates of 602 and 518 mg CH4 m−2 yr−1, respectively. In these regions, favourable annual soil moisture content ( ∼  20 % saturation and low seasonal temperature variations (variations  <   ∼  6 °C provided optimal conditions for soil methanotrophy and soil–atmosphere gas exchange

  2. Occuptional Health and Safety and Employer Motivation

    DEFF Research Database (Denmark)

    Jensen, Per Langå

    2004-01-01

    It is often argued and supported by a number of case studies that investment in human factors and occupational health and safety can pay. But any employer has a number of possible in-vestments, and many of these may have a larger marginal utility than health and safety. In addition it is often...... difficult to calculate the exact pay off for human factors and health and safety – how to calculate higher motivation for instance. The economic benefit as a possible driving force for improvement of occupational health and safety is likely to exist but it must be considered a relatively weak force. Another...... important driving force for improvements in health and safety. No employer likes to be ‘branded’ as immoral, manifested in fines by the labour inspectors or media attention to an unsafe conduct. Strategies to im-prove health and safety therefore need to focus on the legitimacy as the probably strongest...

  3. Occupational Health and Safety and Employer Motivation

    DEFF Research Database (Denmark)

    Hasle, Peter; Jensen, Per Langå

    2004-01-01

    It is often argued and supported by a number of case studies that investment in human factors and occupational health and safety can pay. But any employer has a number of possible in-vestments, and many of these may have a larger marginal utility than health and safety. In addition it is often...... difficult to calculate the exact pay off for human factors and health and safety – how to calculate higher motivation for instance. The economic benefit as a possible driving force for improvement of occupational health and safety is likely to exist but it must be considered a relatively weak force. Another...... important driving force for improvements in health and safety. No employer likes to be ‘branded’ as immoral, manifested in fines by the labour inspectors or media attention to an unsafe conduct. Strategies to im-prove health and safety therefore need to focus on the legitimacy as the probably strongest...

  4. Treatment motivation of men with ED: what motivates men with ED to seek professional help and how can women support their partners?

    Science.gov (United States)

    Gerster, S; Günzler, C; Roesler, C; Leiber, C; Berner, M M

    2013-01-01

    Although ED can impair sexual satisfaction as well as the quality of partnership and life, men affected often avoid seeking treatment. There is growing evidence that women have an influence on their partner's help-seeking behavior. This qualitative study examined men with ED and their female partners in order to detect motivational factors for men to seek treatment and motivational actions of the women to support their partners. Twelve couples took part in a semi-structured telephone interview, which was performed separately in men and women. Analysis was on the basis of the Grounded Theory. The identified motivational factors could be divided into extrinsic (for example, media, female partner) and intrinsic (for example, desire to clarify the cause of the ED, hope for improvement) factors. Women can support their partners in treatment-seeking through various motivational actions such as talking with each other, showing interest and dealing actively with the problem, appealing to the male self-esteem, supporting the doctor's visit, forcing the treatment, active cooperation and participation in the treatment or initiating sexual intercourse. On the basis of these findings, recommendations for women were developed to support their partners and increase the probability of help-seeking behavior.

  5. Emergence of nonwhite noise in Langevin dynamics with magnetic Lorentz force

    Science.gov (United States)

    Chun, Hyun-Myung; Durang, Xavier; Noh, Jae Dong

    2018-03-01

    We investigate the low mass limit of Langevin dynamics for a charged Brownian particle driven by a magnetic Lorentz force. In the low mass limit, velocity variables relaxing quickly are coarse-grained out to yield effective dynamics for position variables. Without the Lorentz force, the low mass limit is equivalent to the high friction limit. Both cases share the same Langevin equation that is obtained by setting the mass to zero. The equivalence breaks down in the presence of the Lorentz force. The low mass limit cannot be achieved by setting the mass to zero. The limit is also distinct from the large friction limit. We derive the effective equations of motion in the low mass limit. The resulting stochastic differential equation involves a nonwhite noise whose correlation matrix has antisymmetric components. We demonstrate the importance of the nonwhite noise by investigating the heat dissipation by a driven Brownian particle, where the emergent nonwhite noise has a physically measurable effect.

  6. Effects of β₂-agonists on force during and following anoxia in rat extensor digitorum longus muscle

    DEFF Research Database (Denmark)

    Fredsted, A; Gissel, H; Ortenblad, N

    2012-01-01

    of salbutamol on force recovery were prevented by blocking the Na(+),K(+)- pumps with ouabain or by blocking glycolysis with 2-deoxyglucose. Dibutyryl cAMP (1 mM) or theophylline (1 mM) also improved force recovery remarkably. In anoxic muscles, salbutamol decreased intracellular Na(+), increased (86)Rb uptake...

  7. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later. Often, two separate uptake ...

  8. Influence of compression forces on tablets disintegration by AC Biosusceptometry.

    Science.gov (United States)

    Corá, Luciana A; Fonseca, Paulo R; Américo, Madileine F; Oliveira, Ricardo B; Baffa, Oswaldo; Miranda, José Ricardo A

    2008-05-01

    Analysis of physical phenomena that occurs during tablet disintegration has been studied by several experimental approaches; however none of them satisfactorily describe this process. The aim of this study was to investigate the influence of compression force on the tablets by associating the AC Biosusceptometry with consolidated methods in order to validate the biomagnetic technique as a tool for quality control in pharmaceutical processes. Tablets obtained at five compression levels were submitted to mechanical properties tests. For uncoated tablets, water uptake and disintegration force measurements were performed in order to compare with magnetic data. For coated tablets, magnetic measurements were carried out to establish a relationship between physical parameters of the disintegration process. According to the results, differences between the compression levels were found for water uptake, force development and magnetic area variation measurements. ACB method was able to estimate the disintegration properties as well as the kinetics of disintegration process for uncoated and coated tablets. This study provided a new approach for in vitro investigation and validated this biomagnetic technique as a tool for quality control for pharmaceutical industry. Moreover, using ACB will also be possible to test these parameters in humans allowing to establish an in vitro/in vivo correlation (IVIVC).

  9. Towards Ontology-Driven Information Systems: Guidelines to the Creation of New Methodologies to Build Ontologies

    Science.gov (United States)

    Soares, Andrey

    2009-01-01

    This research targeted the area of Ontology-Driven Information Systems, where ontology plays a central role both at development time and at run time of Information Systems (IS). In particular, the research focused on the process of building domain ontologies for IS modeling. The motivation behind the research was the fact that researchers have…

  10. AN EMPIRICAL SURVEY ON BASIC MILITARY TRAINING IN SLOVENIAN ARMED FORCES

    Directory of Open Access Journals (Sweden)

    Maja GARB

    2014-04-01

    Full Text Available Before employment in the Slovenian Armed Forces, all candidates have to finish basic military training. The empirical survey, done in 2011 on a group of military candidates in a Slovenian Training Center, checked the motivation, level of skills and education, attitudes of leaders, military identity, prestige and social support of these candidates. The results confirmed the skills’ and fighters’ orientation of Slovenian soldiers, but surprised with the paleomodern motivators for military job.

  11. Coulomb-Driven Relativistic Electron Beam Compression.

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Xiang, Dao; Zhang, Jie

    2018-01-26

    Coulomb interaction between charged particles is a well-known phenomenon in many areas of research. In general, the Coulomb repulsion force broadens the pulse width of an electron bunch and limits the temporal resolution of many scientific facilities such as ultrafast electron diffraction and x-ray free-electron lasers. Here we demonstrate a scheme that actually makes use of the Coulomb force to compress a relativistic electron beam. Furthermore, we show that the Coulomb-driven bunch compression process does not introduce additional timing jitter, which is in sharp contrast to the conventional radio-frequency buncher technique. Our work not only leads to enhanced temporal resolution in electron-beam-based ultrafast instruments that may provide new opportunities in probing material systems far from equilibrium, but also opens a promising direction for advanced beam manipulation through self-field interactions.

  12. Coulomb-Driven Relativistic Electron Beam Compression

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Xiang, Dao; Zhang, Jie

    2018-01-01

    Coulomb interaction between charged particles is a well-known phenomenon in many areas of research. In general, the Coulomb repulsion force broadens the pulse width of an electron bunch and limits the temporal resolution of many scientific facilities such as ultrafast electron diffraction and x-ray free-electron lasers. Here we demonstrate a scheme that actually makes use of the Coulomb force to compress a relativistic electron beam. Furthermore, we show that the Coulomb-driven bunch compression process does not introduce additional timing jitter, which is in sharp contrast to the conventional radio-frequency buncher technique. Our work not only leads to enhanced temporal resolution in electron-beam-based ultrafast instruments that may provide new opportunities in probing material systems far from equilibrium, but also opens a promising direction for advanced beam manipulation through self-field interactions.

  13. The Development of a Bi-Lingual Assessment Instrument to Measure Agentic and Communal Consumer Motives in English and French.

    Science.gov (United States)

    Friedman, Mike; Bartier, Anne-Laure; Lown, Josh; Hopwood, Christopher J

    2016-01-01

    Consumer behavior is driven, in part, by the degree to which goods and services appeal to underlying motives for agency and communion. The purpose of this research was to develop a brief individual differences measure of these motivations for use in behavioral research and theoretical and applied consumer psychology and marketing studies. We employed a bi-lingual scale development procedure to create the 10-item Agentic and Communal Consumer Motivation Inventory (ACCMI) in English and French. Two studies show that the ACCMI is language invariant, demonstrates convergent and discriminant validity with consumer, motivational, and interpersonal constructs, and predicts evaluations of products described in agentic and communal terms, respectively, in both languages. The general conclusion of this research is that agency and communion provide a useful framework for understanding and studying consumer buying motivations. Discussion focuses on the relevance of motivational factors for studying human behavior and the applied utility of the ACCMI.

  14. The development of a bi-lingual assessment instrument to measure agentic and communal consumer motives in English and French

    Directory of Open Access Journals (Sweden)

    Mike Friedman

    2016-08-01

    Full Text Available Consumer behavior is driven, in part, by the degree to which goods and services appeal to underlying motives for agency and communion. The purpose of this research was to develop a brief individual differences measure of these motivations for use in behavioral research and theoretical and applied consumer psychology and marketing studies. We employed a bi-lingual scale development procedure to create the 10-item Agentic and Communal Consumer Motivation Inventory (ACCMI in English and French. Two studies show that the ACCMI is language invariant, demonstrates convergent and discriminant validity with consumer, motivational, and interpersonal constructs, and predicts evaluations of products described in agentic and communal terms, respectively, in both languages. The general conclusion of this research is that agency and communion provide a useful framework for understanding and studying consumer buying motivations. Discussion focuses on the relevance of motivational factors for studying human behavior and the applied utility of the ACCMI.

  15. The Development of a Bi-Lingual Assessment Instrument to Measure Agentic and Communal Consumer Motives in English and French

    Science.gov (United States)

    Friedman, Mike; Bartier, Anne-Laure; Lown, Josh; Hopwood, Christopher J.

    2016-01-01

    Consumer behavior is driven, in part, by the degree to which goods and services appeal to underlying motives for agency and communion. The purpose of this research was to develop a brief individual differences measure of these motivations for use in behavioral research and theoretical and applied consumer psychology and marketing studies. We employed a bi-lingual scale development procedure to create the 10-item Agentic and Communal Consumer Motivation Inventory (ACCMI) in English and French. Two studies show that the ACCMI is language invariant, demonstrates convergent and discriminant validity with consumer, motivational, and interpersonal constructs, and predicts evaluations of products described in agentic and communal terms, respectively, in both languages. The general conclusion of this research is that agency and communion provide a useful framework for understanding and studying consumer buying motivations. Discussion focuses on the relevance of motivational factors for studying human behavior and the applied utility of the ACCMI. PMID:27563295

  16. Stochastically-forced Decadal Variability in Australian Rainfall

    Science.gov (United States)

    Taschetto, A.

    2015-12-01

    Iconic Australian dry and wet periods were driven by anomalous conditions in the tropical oceans, such as the worst short-term drought in the southeast in 1982 associated with the strong El Niño and the widespread "Big Wet" in 1974 linked with a La Niña event. The association with oceanic conditions makes droughts predictable to some extent. However, prediction can be difficult when there is no clear external forcing such as El Niños. Can dry spells be triggered and maintained with no ocean memory? In this study, we investigate the potential role of internal multi-century atmospheric variability in controlling the frequency, duration and intensity of long-term dry and wet spells over Australia. Two multi-century-scale simulations were performed with the NCAR CESM: (1) a fully-coupled simulation (CPLD) and (2) an atmospheric simulation forced by a seasonal SST climatology derived from the coupled experiment (ACGM). Results reveal that droughts and wet spells can indeed be generated by internal variability of the atmosphere. Those internally generated events are less severe than those forced by oceanic variability, however the duration of dry and wet spells longer than 3 years is comparable with and without the ocean memory. Large-scale ocean modes of variability seem to play an important role in producing continental-scale rainfall impacts over Australia. While the Pacific Decadal Oscillation plays an important role in generating droughts in the fully coupled model, perturbations of monsoonal winds seem to be the main trigger of dry spells in the AGCM case. Droughts in the mid-latitude regions such as Tasmania can be driven by perturbations in the Southern Annular Mode, not necessarily linked to oceanic conditions even in the fully-coupled model. The mechanisms behind internally-driven mega-droughts and mega-wets will be discussed.

  17. Axion forces, gravity experiments and T violation

    International Nuclear Information System (INIS)

    Moody, J.E.

    1984-01-01

    A variety of light, weakly-coupled bosons have recently been suggested. Among them is the axion. This thesis considers the possibility of detecting axions or other light bosons via the macroscopic forces they mediate. The motivation for the axion is reviewed along with a detailed calculation of its mass and couplings. The microphysical basis of macroscopic forces is described and the three distinct axion force laws are thereby obtained. Of particular interest is the unique P and T violating monopole-dipole force. The magnitudes and ranges of axion forces are compared with the existing experimental limits. The possibilities for searching for (monopole) 2 , spin-spin and monopole-dipole forces are evaluated. Monopole-dipole experiments seem promising because the sensitive high-Q techniques of gravity wave research are applicable. Ultimate sensitivity, as limited by thermal noise, is evaluated for crystal oscillators and levitated systems. The very interesting problem of quantum uncertainty in weak force measurement is considered along with a way of getting around it called back action evasion. This is followed by a presentation of signal to noise analysis which folds together amplifier noise, quantum uncertainty, and Langevin noise

  18. Job satisfaction and motivation: how do we inspire employees?

    Science.gov (United States)

    Alshallah, Sahar

    2004-01-01

    Productivity is defined as the efficient and effective use of resources with minimum waste and effort to achieve outcome. We live in a world that has limited resources. The health care industry faces this limitation more than any other industry. With these challenges facing health care administrators, the concept of productivity, job satisfaction and motivation become very important. Employee satisfaction and retention have always been an important issue for physicians, medical centers and businesses in general. Conventional human resources theories, developed some 50 years ago by Maslow and Herzberg, suggest that satisfied employees tend to be more productive, creative and committed to their employers. People are essential to productivity. The success of productivity improvement strategy is dependent on employee commitment, job satisfaction, skills, and motivation. Maslow's theory consists of a 5-level pyramid: physiologic or basic survival; physical and mental safety; sense of belonging; accomplishment, creativity, and growth; and self-actualization. Herzberg's theory suggests there are 2 groups of factors: hygiene (which satisfy) and motivation. The terms "job satisfaction" and "motivation" have, in my experience, become used interchangeably. There is a difference. Job satisfaction is an individual's emotional response to his or her current job condition, while motivation is the driving force to pursue and satisfy one's needs. Maslow and Herzberg's theories can be easily applied to the workplace. Managers can help employees achieve overall job satisfaction, which, with the employee's internal motivation drive, increase performance on the job.

  19. Arginine promotes Proteus mirabilis motility and fitness by contributing to conservation of the proton gradient and proton motive force.

    Science.gov (United States)

    Armbruster, Chelsie E; Hodges, Steven A; Smith, Sara N; Alteri, Christopher J; Mobley, Harry L T

    2014-10-01

    Swarming contributes to Proteus mirabilis pathogenicity by facilitating access to the catheterized urinary tract. We previously demonstrated that 0.1-20 mmol/L arginine promotes swarming on normally nonpermissive media and that putrescine biosynthesis is required for arginine-induced swarming. We also previously determined that arginine-induced swarming is pH dependent, indicating that the external proton concentration is critical for arginine-dependent effects on swarming. In this study, we utilized survival at pH 5 and motility as surrogates for measuring changes in the proton gradient (ΔpH) and proton motive force (μH(+) ) in response to arginine. We determined that arginine primarily contributes to ΔpH (and therefore μH(+) ) through the action of arginine decarboxylase (speA), independent of the role of this enzyme in putrescine biosynthesis. In addition to being required for motility, speA also contributed to fitness during infection. In conclusion, consumption of intracellular protons via arginine decarboxylase is one mechanism used by P. mirabilis to conserve ΔpH and μH(+) for motility. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  20. Assessment of plant-driven uptake and translocation of clofibric acid by Scirpus validus.

    Science.gov (United States)

    Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Ng, Wun Jern; Tan, Soon Keat

    2013-07-01

    Pharmaceutical compounds are now considered as emerging contaminants of environmental concern. The overall objective of this study was to evaluate the uptake and translocation of clofibric acid (CA) by the macrophyte Scirpus validus growing hydroponically. A set of the three replicates was established for each exposure time and for each CA concentration. Plants were grown in 4 L vessels (four plants per vessel corresponding to the three exposure period studies, i.e., 7, 14, 18, and 21 days) which contained an aerated modified Hoagland nutrient solution that was spiked with CA at concentrations of 0.5, 1.0, and 2.0 mg L(-1). At each exposure period, CA concentration was measured in the nutrient solutions. A sea sand disruption method was employed for the extraction of CA from plant tissues. The determination of the pharmaceutical concentration was carried out using solid phase extraction (SPE) followed by chromatographic analysis. The quantification of CA concentrations in both nutrient solutions (after SPE) and plant tissues (after extraction) was conducted by chromatographic analysis. CA concentrations of 5.4-26.8 μg g(-1) (fresh weight) were detected in the roots and 7.2-34.6 μg g(-1) (fresh weight) in the shoots after 21 days. Mass balance calculations showed that S. validus uptake alone accounted for a significant contribution (6-13% for the roots and 22-49% for the shoots) of the total loss of CA. The bioaccumulation factors (BAFs) based on fresh weight for the roots ranged from 6.6 to 23.2, while values for the shoots ranged from 9.5 to 32.1. All the BAFs for the shoots were greater than those in the roots, implying that CA has greater tendency to be translocated to the shoots, rather than the roots of S. validus. All the shoot-to-root concentration ratios were more than 1, denoting that the shoots of S. validus do preferentially accumulate CA. We demonstrated that CA can be actively taken up, subsequently translocated and accumulated by aboveground

  1. Motivational and Emotional Influences on Cognitive Control in Depression: A Pupillometry Study

    Science.gov (United States)

    Jones, Neil P.; Siegle, Greg J.; Mandell, Darcy

    2014-01-01

    Depressed people perform poorly on cognitive tasks, however under certain conditions they show intact cognitive performance with physiological reactivity consistent with needing to recruit additional cognitive control. We hypothesize that this apparent compensation is driven by the presence of affective processes (e.g., state anxiety) which in turn are moderated by the depressed individual’s motivational state. Clarifying these processes may help researchers identify targets for treatment that if addressed may improve depressed patients’ cognitive functioning. To test this hypothesis, 36 participants with unipolar depression and 36 never-depressed controls completed a problem-solving task modified to elicit anxiety. Participants completed measures of motivation, anxiety, sadness, and rumination, while pupillary responses were continuously measured during problem-solving as an index of cognitive control. Anxiety increased throughout the task for all participants, while both sadness and rumination were decreased during the task. In addition, anxiety more strongly affected planning accuracy in depressed participants relative to controls, regardless of participants’ levels of motivation. In contrast, differential effects of anxiety on pupillary responses were observed as a function of depressed participants’ levels of motivation. Consistent with behavioral results, less-motivated and anxious depressed participants demonstrated smaller pupillary responses, whereas more highly-motivated and anxious depressed participants demonstrated larger pupillary responses than controls. Strong effects of sadness and rumination on cognitive control in depression were not observed. Thus, we conclude that anxiety inhibits the recruitment of cognitive control in depression and that a depressed individual’s motivational state determines, in part, whether they are able to compensate by recruiting additional cognitive control. PMID:25280561

  2. Motivating employees through incentives: productive or a counterproductive strategy.

    Science.gov (United States)

    Qayum, Mehran; Sawal, Shefa Haider; Khan, Hassan Mehmood

    2014-05-01

    The disparity between human resource in health and provision of health services is a growing concern worldwide. Many developing countries are facing this crisis and therefore human resource in health is considered a high priority on their agenda.This imbalance between supplies of human resource is exacerbated by migration of health workers in many countries. Understanding the motivational factor is an important aspect to retain the migrating health workforce. This paper analyses the role of financial and non financial incentives in motivating the health work force. A review of available literature was conducted to understand the role of motivational factor in retaining health workforce. A review of current literature found that an incentive plays a key role in motivating a health worker. Financial incentives are useful in improving the compliance to standard policies and procedures. Comprehensive integrated incentive system approach should be established to develop a sustainable health workforce with required skill. Likewise monetary incentives should be linked to adherence to provincial and national guidelines and procedures. Sustainability could be ensured by commitment of government, political will and involvement of key stakeholders and decision makers.

  3. Sources of motivation for abstinence: a replication analysis of the reasons for quitting questionnaire.

    Science.gov (United States)

    Downey, L; Rosengren, D B; Donovan, D M

    2001-01-01

    The Reasons for Quitting Questionnaire (RFQ) as modified by McBride and colleagues (C. M. McBride et al., 1994) for use with substance users other than tobacco smokers, was administered to individuals approved for public-sector addiction treatment. Four motivation dimensions, similar to those found by McBride et al., were identified: self-concept issues, health concerns, legal issues, and social influence. A forced two-component solution yielded dimensions interpretable as intrinsic and extrinsic motivation. Self-concept issues provided the highest levels of motivation for abstinence in this sample, with moderate levels provided by health concerns, and the lowest levels provided by legal and social influence components. Intrinsic motivation was higher than extrinsic motivation. Logistic regression models, with adjustment for total motivation, tested the association of successful abstinence during a follow-up period with baseline extrinsic and intrinsic motivation, and with the difference between intrinsic and extrinsic levels. All three associations were significant: intrinsic motivation (positive association), extrinsic motivation (negative association), and the difference score (positive association). The results suggest the usefulness of the 20-item modified RFQ in evaluating motivation for abstinence among treatment seekers exhibiting severe negative consequences of addiction. Testing with samples varying in severity of addiction consequences is recommended.

  4. Uptake, translocation, and toxicity of gold nanorods in maize

    Science.gov (United States)

    Moradi Shahmansouri, Nastaran

    Nanomaterials are widely used in many different products, such as electronics, cosmetics, industrial goods, biomedical uses, and other material applications. The heavy emission of nanomaterials into the environment has motived increasing concern regarding the effects on ecosystems, food chains, and, human health. Plants can tolerate a certain amount of natural nanomaterials, but large amounts of ENMs released from a variety of industries could be toxic to plants and possibly threaten the ecosystem. Employing phytoremediation as a contamination treatment method may show promise. However a pre-requisite to successful treatment is a better understanding of the behavior and effects of nanomaterials within plant systems. This study is designed to investigate the uptake, translocation, bioavailability, and toxicity of gold nanorods in maize plants. Maize is an important food and feed crop that can be used to understand the potential hazardous effects of nanoparticle uptake and distribution in the food chain. The findings could be an important contribution to the fields of phytoremediation, agri-nanotechnology, and nanoparticle toxicity on plants. In the first experiment, hydroponically grown maize seedlings were exposed to similar doses of commercial non-coated gold nanorods in three sizes, 10x34 nm, 20x75 nm, and 40x96 nm. The three nanorod species were suspended in solutions at concentrations of 350 mg/l, 5.8 mg/l, and 14 mg/l, respectively. Maize plants were exposed to all three solutions resulting in considerably lower transpiration and wet biomass than control plants. Likewise, dry biomass was reduced, but the effect is less pronounced than that of transpiration and wet biomass. The reduced transpiration and water content, which eventually proved fatal to exposed plants, were most likely a result of toxic effect of gold nanorod, which appeared to physically hinder the root system. TEM images proved that maize plants can uptake gold particles and accumulate them in

  5. The suprachiasmatic nucleus drives day-night variations in postprandial triglyceride uptake into skeletal muscle and brown adipose tissue.

    Science.gov (United States)

    Moran-Ramos, Sofía; Guerrero-Vargas, Natali N; Mendez-Hernandez, Rebeca; Basualdo, Maria Del Carmen; Escobar, Carolina; Buijs, Ruud M

    2017-12-01

    What is the central question of this study? What are the factors influencing day-night variations in postprandial triglycerides? What is the main finding and its importance? Rats show low postprandial plasma triglyceride concentrations early in the active period that are attributable to a higher uptake by skeletal muscle and brown adipose tissue. We show that these day-night variations in uptake are driven by the suprachiasmatic nucleus, probably via a Rev-erbα-mediated mechanism and independent of locomotor activity. These findings highlight that the suprachiasmatic nucleus has a major role in day-night variations in plasma triglycerides and that disturbances in our biological clock might be an important risk factor contributing to development of postprandial hyperlipidaemia. Energy metabolism follows a diurnal pattern, mainly driven by the suprachiasmatic nucleus (SCN), and disruption of circadian regulation has been linked to metabolic abnormalities. Indeed, epidemiological evidence shows that night work is a risk factor for cardiovascular disease, and postprandial hyperlipidaemia is an important contributor. Therefore, the aim of this work was to investigate the factors that drive day-night variations in postprandial triglycerides (TGs). Intact and SCN-lesioned male Wistar rats were subjected to an oral fat challenge during the beginning of the rest phase (day) or the beginning of the active phase (night). The plasma TG profile was evaluated and tissue TG uptake assayed. After the fat challenge, intact rats showed lower postprandial plasma TG concentrations early in the night when compared with the day. However, no differences were observed in the rate of intestinal TG secretion between day and night. Instead, there was a higher uptake of TG by skeletal muscle and brown adipose tissue early in the active phase (night) when compared with the rest phase (day), and these variations were abolished in rats bearing bilateral SCN lesions. Rev-erbα gene expression

  6. Simulation of barotropic wind-driven circulation in tbe Bay of Bengal and Andaman Sea during premonsoon and postmonsoon seasons

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Bahulayan, N.

    Two-dimensional vertically integrated model has been used to simulate depth-mean wind-driven circulation during premonsoon and postmonsoon seasons in the upper layers of the Bay of Bengal and Andaman Sea. The model is integrated for 365 d, forcEd...

  7. Uptake of nuclides by plants

    International Nuclear Information System (INIS)

    Greger, Maria

    2004-04-01

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate

  8. Uptake of nuclides by plants

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2004-04-01

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

  9. Gait Planning Research for an Electrically Driven Large-Load-Ratio Six-Legged Robot

    Directory of Open Access Journals (Sweden)

    Hong-Chao Zhuang

    2017-03-01

    Full Text Available Gait planning is an important basis for the walking of a legged robot. To improve the walking stability of multi-legged robots and to reduce the impact force between the foot and the ground, gait planning strategies are presented for an electrically driven large-load-ratio six-legged robot. First, the configuration and walking gait of the electrically driven large-load-ratio six-legged robot are designed. The higher-stable swing sequences of legs and typical walking modes are respectively obtained. Based on the Denavit–Hartenberg (D–H method, the analyses of the forward and inverse kinematics are implemented. The mathematical models of the articulated rotation angles are respectively established. In view of the buffer device installed at the end of shin to decrease the impact force between the foot and the ground, an initial lift height of the leg is brought into gait planning when the support phase changes into the transfer phase. The mathematical models of foot trajectories are established. Finally, a prototype of the electrically driven large-load-ratio six-legged robot is developed. The experiments of the prototype are carried out regarding the aspects of the walking speed and surmounting obstacle. Then, the reasonableness of gait planning is verified based on the experimental results. The proposed strategies of gait planning lay the foundation for effectively reducing the foot–ground impact force and can provide a reference for other large-load-ratio multi-legged robots.

  10. Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation

    Directory of Open Access Journals (Sweden)

    Feng Xin

    2007-03-01

    Full Text Available Abstract Background There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated. Methods Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy, and a steering wheel platform (TheraDrive were tested separately with the UniTherapy software. Stroke subjects with hemiparesis and able-bodied subjects completed tracking activities with the devices in different positions. We quantify motor performance across subject groups and across device platforms and muscle activation across devices at two positions in the arm workspace. Results Trends in the assessment metrics were consistent across devices with able-bodied and high functioning strokes subjects being significantly more accurate and quicker in their motor performance than low functioning subjects. Muscle activation patterns were different for shoulder and elbow across different devices and locations. Conclusion The Robot/CAMR suite has potential for stroke rehabilitation. By manipulating hardware and software variables, we can create personalized therapy environments that engage patients, address their therapy need, and track their progress. A larger longitudinal study is still needed to evaluate these systems in under-supervised environments such as the home.

  11. Harnessing motivational forces in the promotion of physical activity: the Community Health Advice by Telephone (CHAT) project.

    Science.gov (United States)

    King, Abby C; Friedman, Robert; Marcus, Bess; Castro, Cynthia; Forsyth, LeighAnn; Napolitano, Melissa; Pinto, Bernardine

    2002-10-01

    Physical inactivity among middle- and older-aged adults is pervasive, and is linked with numerous chronic conditions that diminish health and functioning. Counselor-directed physical activity programs may enhance extrinsic motivation (reflected in social influence theories, such as self-presentation theory) and, in turn, physical activity adherence, while the counselor is in charge of program delivery. However, external influences can undermine intrinsic motivation, making it more difficult to maintain physical activity once counselor-initiated contact ends. In contrast, programs that diminish the socially evaluative and controlling aspects of the counseling interchange may promote intrinsic motivation (described in cognitive evaluation theory), and, thus, physical activity maintenance, even when counselor-initiated contact ceases. The objective of the Community Health Advice by Telephone (CHAT) project is to compare these two theories by conducting a randomized controlled trial evaluating the effects of a telephone-administered counseling program delivered by a person (social influence enhancement) or computer (cognitive evaluation enhancement) on physical activity adoption and maintenance over 18 months. Healthy, sedentary adults (n = 225) aged 55 years and older are randomized to one of these programs or to a control arm. This study will contribute to advancing motivational theory as well as provide information on the sustained effectiveness of interventions with substantial public health applicability.

  12. Internally driven inertial waves in geodynamo simulations

    Science.gov (United States)

    Ranjan, A.; Davidson, P. A.; Christensen, U. R.; Wicht, J.

    2018-05-01

    Inertial waves are oscillations in a rotating fluid, such as the Earth's outer core, which result from the restoring action of the Coriolis force. In an earlier work, it was argued by Davidson that inertial waves launched near the equatorial regions could be important for the α2 dynamo mechanism, as they can maintain a helicity distribution which is negative (positive) in the north (south). Here, we identify such internally driven inertial waves, triggered by buoyant anomalies in the equatorial regions in a strongly forced geodynamo simulation. Using the time derivative of vertical velocity, ∂uz/∂t, as a diagnostic for traveling wave fronts, we find that the horizontal movement in the buoyancy field near the equator is well correlated with a corresponding movement of the fluid far from the equator. Moreover, the azimuthally averaged spectrum of ∂uz/∂t lies in the inertial wave frequency range. We also test the dispersion properties of the waves by computing the spectral energy as a function of frequency, ϖ, and the dispersion angle, θ. Our results suggest that the columnar flow in the rotation-dominated core, which is an important ingredient for the maintenance of a dipolar magnetic field, is maintained despite the chaotic evolution of the buoyancy field on a fast timescale by internally driven inertial waves.

  13. Nonlinear response and bistability of driven ion acoustic waves

    Science.gov (United States)

    Akbari-Moghanjoughi, M.

    2017-08-01

    The hydrodynamic model is used to obtain a generalized pseudoforce equation through which the nonlinear response of periodically driven ion acoustic waves is studied in an electron-ion plasma with isothermal and adiabatic ion fluids. The pseudotime series, corresponding to different driving frequencies, indicates that nonlinearity effects appear more strongly for smaller frequency values. The existence of extra harmonic resonances in the nonlinear amplitude spectrum is a clear indication of the interaction of an external force with harmonic components of the nonlinear ion acoustic waves. It is shown that many plasma parameters significantly and differently affect the nonlinear resonance spectrum of ion acoustic excitations. A heuristic but accurate model for the foldover effect is used which quite satisfactorily predicts the bistability of driven plasma oscillations. It is remarked that the characteristic resonance peak of isothermal ion plasma oscillations appears at lower frequencies but is stronger compared to that of adiabatic ions. Comparison of the exact numerical results for fully nonlinear and approximate (weakly nonlinear) models indicates that a weakly nonlinear model exaggerates the hysteresis and jump phenomenon for higher values of the external force amplitude.

  14. The creating force of minority dissent : A motivated information processing perspective

    NARCIS (Netherlands)

    De Dreu, Carsten K. W.; Nijstad, Bernard A.; Baas, Matthijs; Bechtoldt, Myriam N.

    2008-01-01

    Sometimes social influence processes are the driving force behind the creation of new products, services, and modes of conduct. In this paper we argue that minority dissent and its ensuing influence provides an example par excellence, and we reviewed and interpret findings on minority influence and

  15. Motivating crowding theory - opening the black box of intrinsic motivation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2010-01-01

    Public employees work for many other reasons than because they are paid for it. In other words, intrinsic motivation is an important determinant for their performance. Nonetheless, public sector organizations increasingly rely on extrinsic motivation factors such as monetary incentives to motivate...... employees. Motivation crowding theory claims that this may be at the expense of intrinsic motivation, if the extrinsic motivation factor is perceived to be controlling. On the other hand, intrinsic motivation will be enhanced (crowded in), if the extrinsic motivation factor is perceived to be supportive......, monetary incentives are found to cause different crowding effects for these different types of intrinsic motivation. The results call for more theoretical work on the drivers of motivation crowding effects and for practitioners to pay more attention to what type of intrinsic motivation is at stake, when...

  16. Discussion on stochastic braking for a single-rail rope-driven lifter

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

    This paper discusses the braking and control of a A-2/73 clip type friction brake system made in FRG - a clamp type brake system made in USSR and an eccentric wheel type brake system made in Poland. Then it analyses a ZGZ auto increasing force type braking system of a single-rail rope driven lifter. The braking principle of the ZGZ system is that the braking blocks insert along the brake base and contact with the ribs of the single-rail. Then the braking would be realized as a function of increasing frictional force.

  17. Achievement Motivation of the High School Students: A Case Study among Different Communities of Goalpara District of Assam

    Science.gov (United States)

    Sarangi, C.

    2015-01-01

    Achievement motivation is a consistent striving force of an individual to achieve success to a certain standard of excellence in competing situation. In this study an attempt was made to study the effect of achievement motivation on the academic achievement of the high school students of tribal and non tribal communities in relation to their sex…

  18. Speech-driven environmental control systems--a qualitative analysis of users' perceptions.

    Science.gov (United States)

    Judge, Simon; Robertson, Zoë; Hawley, Mark; Enderby, Pam

    2009-05-01

    To explore users' experiences and perceptions of speech-driven environmental control systems (SPECS) as part of a larger project aiming to develop a new SPECS. The motivation for this part of the project was to add to the evidence base for the use of SPECS and to determine the key design specifications for a new speech-driven system from a user's perspective. Semi-structured interviews were conducted with 12 users of SPECS from around the United Kingdom. These interviews were transcribed and analysed using a qualitative method based on framework analysis. Reliability is the main influence on the use of SPECS. All the participants gave examples of occasions when their speech-driven system was unreliable; in some instances, this unreliability was reported as not being a problem (e.g., for changing television channels); however, it was perceived as a problem for more safety critical functions (e.g., opening a door). Reliability was cited by participants as the reason for using a switch-operated system as back up. Benefits of speech-driven systems focused on speech operation enabling access when other methods were not possible; quicker operation and better aesthetic considerations. Overall, there was a perception of increased independence from the use of speech-driven environmental control. In general, speech was considered a useful method of operating environmental controls by the participants interviewed; however, their perceptions regarding reliability often influenced their decision to have backup or alternative systems for certain functions.

  19. The β3 -adrenoceptor agonist mirabegron increases human atrial force through β1 -adrenoceptors: an indirect mechanism?

    Science.gov (United States)

    Mo, Weilan; Michel, Martin C; Lee, Xiang Wen; Kaumann, Alberto J; Molenaar, Peter

    2017-08-01

    Mirabegron has been classified as a β 3 -adrenoceptor agonist approved for overactive bladder syndrome. We investigated possible cardiac effects of mirabegron in the absence or presence of β-adrenoceptor subtype antagonists. In view of its phenylethanolamine structure, we investigated whether mirabegron has indirect sympathomimetic activity by using neuronal uptake blockers. Right atrial trabeculae, from non-failing hearts, were paced and contractile force measured at 37°C. Single concentrations of mirabegron were added in the absence or presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), β 3 (L-748,337), β 1 (CGP 20712A), β 2 (ICI 118,551) -adrenoceptor antagonists, neuronal uptake inhibitors desipramine or phenoxybenzamine. Mirabegron significantly increased contractile force in human right atrium (1 μM, 7.6 ± 2.6%, n = 7; 10 μM, 10.2 ± 1.5%, n = 22 compared with (-)-isoprenaline P < 0.05). In the presence of IBMX, mirabegron (10 μM) caused a greater contraction. L-748,337 (100 nM) had no effect on the increase in contractile force caused by mirabegron (10 μM). In contrast, mirabegron (10 μM) reduced contractile force in the presence of CGP 20712A, which was not affected by L-748,337 (100 nM) or ICI 118,551 (50 nM). Mirabegron (10 μM) also reduced contractile force in the presence of desipramine or phenoxybenzamine. Mirabegron increases human atrial force through β 1 - but not β 3 -adrenoceptors. Desipramine and phenoxybenzamine block neuronal uptake and conceivably prevent mirabegron from releasing noradrenaline. A non-specific cardiodepressant effect is not mediated through β 3 (or β 2 )-adrenoceptors, consistent with lack of β 3 -adrenoceptor function on human atrial contractility. © 2017 The British Pharmacological Society.

  20. Transient many-body instability in driven Dirac materials

    Science.gov (United States)

    Pertsova, Anna; Triola, Christopher; Balatsky, Alexander

    The defining feature of a Dirac material (DM) is the presence of nodes in the low-energy excitation spectrum leading to a strong energy dependence of the density of states (DOS). The vanishing of the DOS at the nodal point implies a very low effective coupling constant which leads to stability of the node against electron-electron interactions. Non-equilibrium or driven DM, in which the DOS and hence the effective coupling can be controlled by external drive, offer a new platform for investigating collective instabilities. In this work, we discuss the possibility of realizing transient collective states in driven DMs. Motivated by recent pump-probe experiments which demonstrate the existence of long-lived photo-excited states in DMs, we consider an example of a transient excitonic instability in an optically-pumped DM. We identify experimental signatures of the transient excitonic condensate and provide estimates of the critical temperatures and lifetimes of these states for few important examples of DMs, such as single-layer graphene and topological-insulator surfaces.

  1. Diselenolane-mediated cellular uptake.

    Science.gov (United States)

    Chuard, Nicolas; Poblador-Bahamonde, Amalia I; Zong, Lili; Bartolami, Eline; Hildebrandt, Jana; Weigand, Wolfgang; Sakai, Naomi; Matile, Stefan

    2018-02-21

    The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-β-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

  2. Detecting chameleons through Casimir force measurements

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine; Shaw, Douglas; Mota, David F.

    2007-01-01

    The best laboratory constraints on strongly coupled chameleon fields come not from tests of gravity per se but from precision measurements of the Casimir force. The chameleonic force between two nearby bodies is more akin to a Casimir-like force than a gravitational one: The chameleon force behaves as an inverse power of the distance of separation between the surfaces of two bodies, just as the Casimir force does. Additionally, experimental tests of gravity often employ a thin metallic sheet to shield electrostatic forces; however, this sheet masks any detectable signal due to the presence of a strongly coupled chameleon field. As a result of this shielding, experiments that are designed to specifically test the behavior of gravity are often unable to place any constraint on chameleon fields with a strong coupling to matter. Casimir force measurements do not employ a physical electrostatic shield and as such are able to put tighter constraints on the properties of chameleons fields with a strong matter coupling than tests of gravity. Motivated by this, we perform a full investigation on the possibility of testing chameleon models with both present and future Casimir experiments. We find that present-day measurements are not able to detect the chameleon. However, future experiments have a strong possibility of detecting or rule out a whole class of chameleon models

  3. The Airborne Transmission of Infection Between Flats in High-rise Residential Buildings

    DEFF Research Database (Denmark)

    Gao, N. P.; Niu, J. L.; Perino, M.

    2009-01-01

    Several case clusters occurred in high-rise residential buildings in Hong Kong in the 2003 SARS (the severe acute respiratory syndrome) epidemic, which motivated a series of engineering investigations into the possible airborne transport routes. It is suspected that, driven by buoyancy force...

  4. Key Mechanisms for Employee-Driven Innovation in Governmental Client Organisations

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Wandahl, Søren; Faber, Lene

    2018-01-01

    the mechanisms of organisational trust, innovation safety, organisational practices, cultural settings and the recognition and rewards structure to motivate employees. The decision-making procedures should be transparent especially to the idea-owner and the employees involved, and the implementation and putting......In order to ensure that knowledge and ideas are transformed into innovative contributions, a systematic approach is important. The aim of this research was to identify the specific mechanisms that are key to implementing an innovation process model when conducting Employee-driven Innovation...... into practice should be fast progressed phases in the innovation process....

  5. Motivation in Beyond Budgeting: A Motivational Paradox?

    DEFF Research Database (Denmark)

    Sandalgaard, Niels; Bukh, Per Nikolaj

    In this paper we discuss the role of motivation in relation to budgeting and we analyse how the Beyond Budgeting model functions compared with traditional budgeting. In the paper we focus on budget related motivation (and motivation in general) and conclude that the Beyond Budgeting model...

  6. Influence of multidrug resistance on 18F-FCH cellular uptake in a glioblastoma model

    International Nuclear Information System (INIS)

    Vanpouille, Claire; Jeune, Nathalie le; Clotagatide, Anthony; Dubois, Francis; Kryza, David; Janier, Marc; Perek, Nathalie

    2009-01-01

    Multidrug resistance, aggressiveness and accelerated choline metabolism are hallmarks of malignancy and have motivated the development of new PET tracers like 18 F-FCH, an analogue of choline. Our aim was to study the relationship of multidrug resistance of cultured glioma cell lines and 18 F-FCH tracer uptake. We used an in vitro multidrug-resistant (MDR) glioma model composed of sensitive parental U87MG and derived resistant cells U87MG-CIS and U87MG-DOX. Aggressiveness, choline metabolism and transport were studied, particularly the expression of choline kinase (CK) and high-affinity choline transporter (CHT1). FCH transport studies were assessed in our glioblastoma model. As expected, the resistant cell lines express P-glycoprotein (Pgp), multidrug resistance-associated protein isoform 1 (MRP1) and elevated glutathione (GSH) content and are also more mobile and more invasive than the sensitive U87MG cells. Our results show an overexpression of CK and CHT1 in the resistant cell lines compared to the sensitive cell lines. We found an increased uptake of FCH (in % of uptake per 200,000 cells) in the resistant cells compared to the sensitive ones (U87MG: 0.89±0.14; U87MG-CIS: 1.27±0.18; U87MG-DOX: 1.33±0.13) in line with accelerated choline metabolism and aggressive phenotype. FCH uptake is not influenced by the two ATP-dependant efflux pumps: Pgp and MRP1. FCH would be an interesting probe for glioma imaging which would not be effluxed from the resistant cells by the classic MDR ABC transporters. Our results clearly show that FCH uptake reflects accelerated choline metabolism and is related to tumour aggressiveness and drug resistance. (orig.)

  7. Challenges and complexities of multifrequency atomic force microscopy in liquid environments

    Directory of Open Access Journals (Sweden)

    Santiago D. Solares

    2014-03-01

    Full Text Available This paper illustrates through numerical simulation the complexities encountered in high-damping AFM imaging, as in liquid enviroments, within the specific context of multifrequency atomic force microscopy (AFM. The focus is primarily on (i the amplitude and phase relaxation of driven higher eigenmodes between successive tip–sample impacts, (ii the momentary excitation of non-driven higher eigenmodes and (iii base excitation artifacts. The results and discussion are mostly applicable to the cases where higher eigenmodes are driven in open loop and frequency modulation within bimodal schemes, but some concepts are also applicable to other types of multifrequency operations and to single-eigenmode amplitude and frequency modulation methods.

  8. Challenges and complexities of multifrequency atomic force microscopy in liquid environments.

    Science.gov (United States)

    Solares, Santiago D

    2014-01-01

    This paper illustrates through numerical simulation the complexities encountered in high-damping AFM imaging, as in liquid enviroments, within the specific context of multifrequency atomic force microscopy (AFM). The focus is primarily on (i) the amplitude and phase relaxation of driven higher eigenmodes between successive tip-sample impacts, (ii) the momentary excitation of non-driven higher eigenmodes and (iii) base excitation artifacts. The results and discussion are mostly applicable to the cases where higher eigenmodes are driven in open loop and frequency modulation within bimodal schemes, but some concepts are also applicable to other types of multifrequency operations and to single-eigenmode amplitude and frequency modulation methods.

  9. The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation

    OpenAIRE

    Albrecht, Konstanze; Abeler, Johannes; Weber, Bernd; Falk, Armin

    2014-01-01

    Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards ar...

  10. THE BRAIN CORRELATES OF THE EFFECTS OF MONETARY AND VERBAL REWARDS ON INTRINSIC MOTIVATION

    OpenAIRE

    Konstanze eAlbrecht; Johannes eAbeler; Bernd eWeber; Bernd eWeber; Armin eFalk; Armin eFalk

    2014-01-01

    Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: We do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: While performance-based monetary rewards ar...

  11. Prioritizing Motivational and Satisfactorily Factors of Volunteer Medical and Health Personnel in Natural Disasters

    Directory of Open Access Journals (Sweden)

    Mohsen Aminizadeh

    2016-01-01

    Full Text Available Background: Currently, volunteer forces are among the main members of the healthcare services, particularly in the treatment sector, and play a key role in healthcare and treatment services. Since efficient human resources are the greatest and most important assets of all organizations, they constantly work to train, retain, and get the best of these valuable assets. The main objective of this work was to prioritize the motivational factors and satisfaction of the volunteer forces participating in treatment and health programs in the case of emergencies. Materials and Methods: The study population of this research was all volunteers (N=600 in treatment and health programs of Kerman Province. Using the Morgan Table, 360 subjects were selected. The data-gathering instrument was Andam’s questionnaire of motivational factors with reliability of 0.94, and Galindo-Kuhn and Guzley (2001 questionnaire of satisfaction with reliability of 0.92. To determine research data distribution, Kolmogorov-Smirnov test was applied. Moreover, for data analysis inferential statistics tests of Friedman, Mann–Whitney U, and Kruskal–Wallis were used at significance level of P<0.05. Results: The present research revealed that the most and least important motivational factors in volunteers of treatment and health units were purposeful motivation and financial motivation with average rankings of 5.45 and 1.99, respectively. In addition, among the satisfaction factors, the volunteers reported communication with volunteers and organizational communication as the most and least important satisfaction factors, respectively. The results of this research indicated that the female volunteers participated in volunteer activities with greater occupational, support, progress, and social motivations. In addition, single participants had greater occupational, social, and financial motivations towards participation in these activities as compared to married participants

  12. Physiological and tumoral uptake of 68Ga-DOTATATE. Standardized uptake values and challenges in interpretation

    International Nuclear Information System (INIS)

    Kuyumcu, Serkan; Oezkan, Zeynep Goezde; Sanli, Yasemin; Yilmaz, Ebru; Mudun, Ayse; Adalet, Isik; Unal, Seher

    2013-01-01

    The objective of this study is to determine the range of standardized uptake value (SUV) max of 68Ga-DOTA-tyr3-octreotate (DOTATATE) in normal organs and tumoral lesions and establish uptake unrelated to neuroendocrine tumors (NET). One hundred and twenty patients (57 men, 63 women), who underwent 68 Ga-DOTATATE positron emission tomography (PET)/CT imaging in our institution were analyzed. Patients were indicated for 68 Ga-DOTATATE PET/CT imaging to detect primary tumor or metastasis of suspected or previously known NET, to determine somatostatin receptor (SSTR) positivity and to detect occult source of ectopic Cushing syndrome. Normal range of uptake was calculated for the organs that were proven to have no pathology by either conventional radiological imaging or clinical follow-up, using SUV max as a semiquantitative measure. Uptake and tumor to background (T/B) ratios of tumoral lesions in liver, pancreas, bone, brain and lymph nodes were calculated. Uptakes due to lesions unrelated to NET were also documented. Significant uptake was found in spleen, kidneys, adrenal glands, liver and pituitary gland with mean SUV max of 24.67, 14.30, 13.73, 9.12 and 9.74 respectively. Uptake was measured separately for the pancreatic head and body separately, however, besides a slightly heterogeneous uptake; the difference was not statistically significant. Uptake in the tumoral lesions had high (T/B) ratios with mean SUV max of 28.72, 25.21, 18.28, 34.73 and 12.59 for liver, pancreas, bone, brain and lymph nodes, respectively. Incidental benign tumoral lesions were detected in 3 patients (2.5%) which were meningioma and fibrous dysplasia demonstrating significant and breast fibroadenoma demonstrating mild 68 Ga-DOTATATE uptake. Non-neoplastic processes were detected in 4 patients (14.1%), including postsurgical inflammation, reactive lymph nodes, arthritis and demonstrated faint to mild 68 Ga-DOTATATE uptake, with the exception of significant uptake in accessory spleen. 68 Ga

  13. The Open Access Movement in Latin America. A continuation of the historic clashes between the capitalistic-driven forces against the socializing forces of information and knowledge sharing = El Movimiento Acceso Abierto (Open Access) en Latinoamérica. Una continuación de los históricos ataques de las fuerzas capitalistas contra las de la socialización del compartimento de información y conocimiento. Una opinión personal

    OpenAIRE

    Muela-Meza, Zapopan Martín

    2005-01-01

    This presentation intends to give a Latin America-wide account of the development of the Web-based Open Access movement. It provides a historical account of the class struggles between the capitalistic-driven appropriators of information-knowledge and the socializing and commonalizing forces, and it employs that as a framework to analyse the overall OA movement. It argues the capitalistic-driven pay-per-access publishing system is an irrational framework which should be put aside. It calls fo...

  14. Understanding motivators and barriers of hospital-based obstetric and pediatric health care worker influenza vaccination programs in Australia.

    Science.gov (United States)

    Tuckerman, Jane L; Shrestha, Lexa; Collins, Joanne E; Marshall, Helen S

    2016-07-02

    Understanding motivators and barriers of health care worker (HCW) vaccination programs is important for determining strategies to improve uptake. The aim of this study was to explore key drivers and HCW decision making related to recommended vaccines and seasonal influenza vaccination programs. We used a qualitative approach with semi-structured one-to-one interviews with 22 HCWs working at a tertiary pediatric and obstetric hospital in South Australia. A thematic analysis and coding were used to examine data. Key motivators that emerged included: sense of responsibility, convenience and ease of access, rotating trolleys, the influenza vaccine being free, basic knowledge about influenza and influenza vaccination, peer pressure, personal values and family culture, as well as the culture of support for the program. Personal decisions were the major barrier to HCWs receiving the influenza vaccine which were predominantly self-protection related or due to previous experience or fear of adverse reactions. Other barriers that emerged were misconceptions about the influenza vaccine, needle phobia and privacy concerns. This study identified both attitudinal and structural barriers that could be addressed to improve uptake of the seasonal influenza vaccine.

  15. Phase-locking of driven vortex lattices with transverse ac force and periodic pinning

    International Nuclear Information System (INIS)

    Reichhardt, Charles; Kolton, Alejandro B.; Dominguez, Daniel; Gronbech-Jensen, Niels

    2001-01-01

    For a vortex lattice moving in a periodic array we show analytically and numerically that a new type of phase locking occurs in the presence of a longitudinal dc driving force and a transverse ac driving force. This phase locking is distinct from the Shapiro step phase locking found with longitudinal ac drives. We show that an increase in critical current and a fundamental phase-locked step width scale with the square of the driving ac amplitude. Our results should carry over to other systems such as vortex motion in Josephson-junction arrays

  16. Motives of consumers following a vegan diet and their attitudes towards animal agriculture.

    Science.gov (United States)

    Janssen, Meike; Busch, Claudia; Rödiger, Manika; Hamm, Ulrich

    2016-10-01

    The number of consumers following a vegan diet has notably increased in many industrialised countries and it is likely that their influence on the food sector will continue to grow. The aim of the present study was to identify different segments of consumers according to their motivation for following a vegan diet. Another objective was to analyse the attitudes of these consumers towards animal agriculture. The main focus was to determine whether all consumers following a vegan diet oppose animal agriculture in general or if some of these consumers accept certain forms of animal agriculture. The 2014 study, conducted at seven vegan supermarkets in Germany, was based on face-to-face interviews with 329 consumers following a vegan diet. The open question on consumer motivations for adopting a vegan diet revealed three main motives: Animal-related motives (mentioned by 89.7% of the respondents), motives related to personal well-being and/or health (69.3%), and environment-related motives (46.8%). The two-step cluster analysis identified five consumer segments with different motivations for following a vegan diet. The vast majority of respondents (81.8%) mentioned more than one motive. We conclude that making a dichotomous segmentation into ethical versus self-oriented consumers, as previous authors have done, disregards the fact that many consumers following a vegan diet are driven by more than one motive. The consumer segments had significantly different attitudes towards animal agriculture. We identified consumers following a vegan diet (about one third of the sample) who might be open to forms of animal agriculture guaranteeing animal welfare standards going beyond current practices. The present study has interesting implications for the food sector and the agricultural sector. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Exhaustion Experiences in Junior Athletes: The Importance of Motivation and Self-Control Competencies.

    Science.gov (United States)

    Jordalen, Gro; Lemyre, Pierre-Nicolas; Durand-Bush, Natalie

    2016-01-01

    Quality of motivation, self-control competencies, as well as past performance experience influence sport participation outcomes in developing athletes. Studies have shown that junior athletes high in self-determined motivation are less prone to experience burnout, while self-control competencies help developing athletes to be conscious and deliberate in their self-regulatory efforts toward elite sport performances and avoid negative sport participation outcomes. Combining the self-determination theory framework and psychosocial theories of self-regulation, the aim of this cross-sectional study was to examine how various types of motivation and self-control competencies together are associated with the development of burnout symptoms in junior athletes. High-level Norwegian winter-sport athletes from elite sport academies ( N = 199; female n = 72; 16-20 years of age) consented to participate. Associations between six types of motivational regulation, self-control, and indices of exhaustion were investigated. We hypothesized that athletes' self-control competencies are important to operate successfully, and influenced by different types of motivation, they are expected to help athletes avoid negative sport participation outcomes such as emotional and physical exhaustion. Structural equation modeling analyses were conducted to analyze these relationships, and results revealed some multifaceted associations. When identifying antecedents of sport participation exhaustion and burnout, there is a need to go beyond the unique framework of motivation theories, and explore what cognitive competencies ensure fulfillment of motivation desires. In the current study, differences in junior athletes' quality of motivation influenced self-control competencies when predicting exhaustion. Interestingly, young athletes driven by self-determined (intrinsic, integrated, and identified), and controlled (introjected and amotivation) regulations in association with self-control offered the

  18. Exhaustion Experiences in Junior Athletes:The Importance of Motivation and Self - Control Competencies

    Directory of Open Access Journals (Sweden)

    Gro Jordalen

    2016-11-01

    Full Text Available Quality of motivation, self-control competencies, as well as past performance experience influence sport participation outcomes in developing athletes. Studies have shown that junior athletes high in self-determined motivation are less prone to experience burnout, while self-control competencies help developing athletes to be conscious and deliberate in their self-regulatory efforts toward elite sport performances and avoid negative sport participation outcomes. Combining the self-determination theory (SDT framework and psychosocial theories of self-regulation, the aim of this cross-sectional study was to examine how various types of motivation and self-control competencies together are associated with the development of burnout symptoms in junior athletes. High-level Norwegian winter-sport athletes from elite sport academies (N = 199; female n = 72; 16 to 20 years of age consented to participate. Associations between six types of motivational regulation, self-control, and indices of exhaustion were investigated. We hypothesized that athletes’ self-control competencies are important to operate successfully, and influenced by different types of motivation, they are expected to help athletes avoid negative sport participation outcomes such as emotional and physical exhaustion. Structural equation modeling analyses were conducted to analyze these relationships, and results revealed some multifaceted associations. When identifying antecedents of sport participation exhaustion and burnout, there is a need to go beyond the unique framework of motivation theories, and explore what cognitive competencies ensure fulfillment of motivation desires. In the current study, differences in junior athletes’ quality of motivation influenced self-control competencies when predicting exhaustion. Interestingly, young athletes driven by self-determined (intrinsic, integrated, and identified, and controlled (introjected and amotivation regulations in association

  19. motivation and physical performance in elite and non-elite trained men

    Directory of Open Access Journals (Sweden)

    BT Crewther

    2016-08-01

    Full Text Available To advance our understanding of the hormonal contribution to athletic performance, we examined the temporal associations between individual changes in testosterone (T and/or cortisol (C concentrations, training motivation and physical performance in elite and non-elite trained men. Two male cohorts classified as elites (n = 12 and non-elites (n = 12 completed five testing sessions over a six-week period. The athletes were tested for salivary T, C, T/C ratio, self-perceived training motivation, countermovement jump (CMJ height and isometric mid-thigh pull peak force (IMTP PF, after which an actual training workout was performed. The elite men reported higher motivation to train and they produced greater CMJ height overall, whereas the non-elites had higher pooled T levels (p < 0.05. No significant group differences in C concentrations, T/C ratio or IMTP PF were found. The individual changes in T levels were positively associated with training motivation in the elite men only (p = 0.033, but the hormonal and motivation measures did not predict CMJ height or IMTP PF in either group. The monitoring of elite and non-elite men across a short training block revealed differences in T levels, motivation and lower-body power, which may reflect training and competitive factors in each group. Despite having lower T levels, the elite athletes showed better linkage between pre-training T fluctuations and subsequent motivation to train. The nature of the performance tests (i.e. single repetition trials could partly explain the lack of an association with the hormonal and motivational measures.

  20. {sup 18}F-FDG uptake at the surgical margin after hepatic resection: Patterns of uptake and differential diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Peungjesada, Silanath [University New Mexico, Department of Radiology, Albuquerque, NM (United States); Aloia, Thomas A. [University of Texas MD Anderson Cancer Center, Department of Surgical Oncology, Unit 444, Houston, TX (United States); Fox, Patricia [University of Texas MD Anderson Cancer Center, Department of Biostatistics, Unit 1411, Houston, TX (United States); Chasen, Beth [University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Unit 1483, Houston, TX (United States); Shin, Sooyoung; Loyer, Evelyne M. [University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Unit 1473, Houston, TX (United States); Baiomy, Ali [Cairo University, National Cancer Center, Cairo (Egypt)

    2015-08-15

    To evaluate the patterns of {sup 18}F-FDG uptake at the surgical margin after hepatectomy to identify features that may differentiate benign and malignant uptake. Patients who had undergone a PET/CT after hepatectomy were identified. Delay between resection and PET/CT, presence of uptake at the surgical margin, pattern of uptake, and maximal standardized value were recorded. The PET/CT findings were correlated with contrast-enhanced CT or MRI. There were 26 patients with increased 18F-FDG uptake; uptake was diffuse in seven and focal in 19. Diffuse uptake was due to inflammation in all cases. Focal uptake was due to recurrence in 12 and inflammation in seven cases. Defining a focal pattern only as a positive for malignancy yielded 100 % sensitivity, 87 % specificity, 37 % false positive rate. As expected, SUV{sub max} was significantly higher for recurrence than inflammation, but did overlap. Contrast-enhanced CT allowed differentiation between malignant and benign uptake in all cases. F-FDG uptake after hepatectomy does not equate to recurrence and yields a high false positive rate. Diffuse uptake did not require additional evaluation in our sample. Focal uptake, however, may be due to recurrence; differentiating benign and malignant nodular uptake relies on optimal contrast-enhanced CT or MRI. (orig.)

  1. Uptake, translocation, and debromination of polybrominated diphenyl ethers in maize

    Institute of Scientific and Technical Information of China (English)

    Moming Zhao; Shuzhen Zhang; Sen Wang; Honglin Huang

    2012-01-01

    Uptake,translocation and debromination of three polybrominated diphenyl ethers(PBDEs),BDE-28,-47 and-99,in maize were studied in a hydroponic experiment.Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability.PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants.Furthermore,PBDE concentrations decreased from roots to stems and then to leaves,and a very clear decreasing gradient was found in segments upwards along the stem.These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize.More highly brominated PBDEs were translocated with more difficulty.Radial translocation of PBDEs from nodes to sheath inside maize was also observed.Both acropetal and radial translocations were enhanced at higher transpiration rates,suggesting that PBDE transport was probably driven by the transpiration stream.Debromination of PBDEs occurred in all parts of the maize,and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences.This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants,elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.

  2. Nanoparticle movement: Plasmonic forces and physical constraints

    International Nuclear Information System (INIS)

    Batson, P.E.; Reyes-Coronado, A.; Barrera, R.G.; Rivacoba, A.; Echenique, P.M.; Aizpurua, J.

    2012-01-01

    Nanoparticle structures observed in aberration-corrected electron microscopes exhibit many types of behavior, some of which are dominated by intrinsic conditions, unrelated to the microscope environment. Some behaviors are clearly driven by the electron beam, however, and the question arises as to whether these are similar to intrinsic mechanisms, useful for understanding nanoscale behavior, or whether they should be regarded as unwanted modification of as-built specimens. We have studied a particular kind of beam–specimen interaction – plasmon dielectric forces caused by the electric fields imposed by a passing swift electron – identifying four types of forced motion, including both attractive and repulsive forces on single nanoparticles, and coalescent and non-coalescent forces in groups of two or more nanoparticles. We suggest that these forces might be useful for deliberate electron beam guided movement of nanoparticles. -- Highlights: ► We investigate the interaction of metal nanoparticles with a high energy electron beam. ► We find forces ranging from 0.1 to 50 pN forces between the metal particles and the beam. ► At moderate distances, dielectric forces are usually small and attractive. ► At sub-Nm distances the forces become repulsive, pushing nanoparticles away from the electron beam. ► While the repulsive behavior is predicted by electromagnetic theory, the detailed origin of the behavior is not yet understood.

  3. Iodide uptake by negatively charged clay interlayers?

    Science.gov (United States)

    Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

    2015-09-01

    Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Ukrainians in German Armed Forces During the Second World War

    OpenAIRE

    Khromeychuk, Olesya

    2015-01-01

    During the Second World War large numbers of inhabitants of central, eastern and southern Europe joined the German Armed Forces. Among them were around 250,000 soldiers who identified themselves as Ukrainian. They served in the Wehrmacht, as well as the Waffen SS; a considerable number of them also served in the auxiliary police. They were motivated to join the German Armed Forces by a combination of different factors. This paper aims to shed some light on the broad range of circumstances tha...

  5. The self-regulation of motivation: Motivational strategies as mediator between motivational beliefs and engagement for learning.

    NARCIS (Netherlands)

    Smit, Karin; De Brabander, Cornelis; Boekaerts, Monique; Martens, Rob

    2017-01-01

    In this research we studied students´ motivational self-regulation as mediator between motivational beliefs and motivational outcomes. Dutch students in pre-vocational secondary education (N=3602, mean age 14) completed a questionnaire on five motivational strategies (Environmental Control,

  6. The Effectiveness of Motivation Training for Increasing Students’ Motivation

    Directory of Open Access Journals (Sweden)

    Fatwa Tentama

    2014-09-01

    Full Text Available Students’ low level of motivation becomes a matter of concern to be addressed immediately. Students' motivation needs to be improved as it is a factor that will affect their lives in the future. This study aims to observe or examine the effectiveness of motivation training in increasing students' motivation.The research method used was the pre-experiment with one group pre-test post-test design. The subjects of this study were 15 boy and girl students of Grade X of SMK who had a low level of motivation. The measuring instruments were the motivation scales given during the pre-test and post-test. The quantitative data were statistically analyzed using the Wilcoxon test with non-parametric measurements to determine the significance of difference in the motivation level before and after the training. The data were tested using SPSS 17.0 for Windows.The result of Wilcoxon analysis to test the hypothesis whether there is a difference between the pre-test and post-test of students' motivation showed that the p = 0.025 (p < 0.05. This means that there was a significant difference between the motivation before the treatment (pre-test and after the treatment (post-test, which indicated that the students' motivation increased after a treatment in the form of motivation training.

  7. Universal Linear Motor Driven Leg Press Dynamometer and Concept of Serial Stretch Loading.

    Science.gov (United States)

    Hamar, Dušan

    2015-08-24

    Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase) or acceleration (in eccentric phase). Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients.

  8. The Effect of Motivational Practices on Volunteer Motivation to ...

    African Journals Online (AJOL)

    The study assesses whether organizations' motivational practices affect volunteer motivation and levels of performance. This study was guided by the following two research questions: first, what motivation practices exist in Volunteer Involving Organizations and whether such affect volunteers' motivation to volunteer again?

  9. Rationalization of dye uptake on titania slides for dye-sensitized solar cells by a combined chemometric and structural approach.

    Science.gov (United States)

    Gianotti, Valentina; Favaro, Giada; Bonandini, Luca; Palin, Luca; Croce, Gianluca; Boccaleri, Enrico; Artuso, Emma; van Beek, Wouter; Barolo, Claudia; Milanesio, Marco

    2014-11-01

    A model photosensitizer (D5) for application in dye-sensitized solar cells has been studied by a combination of XRD, theoretical calculations, and spectroscopic/chemometric methods. The conformational stability and flexibility of D5 and molecular interactions between adjacent molecules were characterized to obtain the driving forces that govern D5 uptake and grafting and to infer the most likely arrangement of the molecules on the surface of TiO2. A spectroscopic/chemometric approach was then used to yield information about the correlations between three variables that govern the uptake itself: D5 concentration, dispersant (chenodeoxycholic acid; CDCA) concentration, and contact time. The obtained regression model shows that large uptakes can be obtained at high D5 concentrations in the presence of CDCA with a long contact time, or in absence of CDCA if the contact time is short, which suggests how dye uptake and photovoltaic device preparation can be optimized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Forces on wheels and fuel consumption in cars

    Science.gov (United States)

    Güémez, J.; Fiolhais, M.

    2013-07-01

    Motivated by real classroom discussions, we analyze the forces acting on moving vehicles, specifically friction on their wheels. In typical front-wheel-drive cars when the car accelerates these forces are in the forward direction in the front wheels, but they are in the opposite direction in the rear wheels. The situation may be intriguing for students, but it may also be helpful and stimulating to clarify the role of friction forces on rolling objects. In this paper we also study the thermodynamical aspects of an accelerating car, relating the distance traveled to the amount of fuel consumed. The fuel consumption is explicitly shown to be Galilean invariant and we identify the Gibbs free energy as the relevant quantity that enters into the thermodynamical description of the accelerating car. The more realistic case of the car's motion with the dragging forces taken into account is also discussed.

  11. Forces on wheels and fuel consumption in cars

    International Nuclear Information System (INIS)

    Güémez, J; Fiolhais, M

    2013-01-01

    Motivated by real classroom discussions, we analyze the forces acting on moving vehicles, specifically friction on their wheels. In typical front-wheel-drive cars when the car accelerates these forces are in the forward direction in the front wheels, but they are in the opposite direction in the rear wheels. The situation may be intriguing for students, but it may also be helpful and stimulating to clarify the role of friction forces on rolling objects. In this paper we also study the thermodynamical aspects of an accelerating car, relating the distance traveled to the amount of fuel consumed. The fuel consumption is explicitly shown to be Galilean invariant and we identify the Gibbs free energy as the relevant quantity that enters into the thermodynamical description of the accelerating car. The more realistic case of the car's motion with the dragging forces taken into account is also discussed. (paper)

  12. Are new medical students' specialty preferences gendered? Related motivational factors at a Dutch medical school.

    Science.gov (United States)

    van Tongeren-Alers, Margret; van Esch, Maartje; Verdonk, Petra; Johansson, Eva; Hamberg, Katarina; Lagro-Janssen, Toine

    2011-01-01

    Female students currently outnumber male students in most medical schools. Some medical specialties are highly gender segregated. Therefore, it is interesting to know whether medical students have early specialization preferences based on their gender. Consequently, we like to know importance stipulated to motivational factors. Our study investigates new medical students' early specialization preferences and motivational factors. New students at a Dutch medical school (n = 657) filled in a questionnaire about specialty preferences (response rate = 94%; 69.5% female, 30.5% male). The students chose out of internal medicine, psychiatry, neurology, pediatrics, surgery, gynecology and family medicine, "other" or "I don't know." Finally, they valued ten motivational factors. Forty percent of the medical students reported no specialty preference yet. Taken together, female medical students preferred pediatrics and wished to combine work and care, whereas male students opted for surgery and valued career opportunities. Gender-driven professional preferences in new medical students should be noticed in order to use competencies. Changes in specialty preferences and motivational factors in pre- and post graduates should further assess the role of medical education.

  13. Impressions of Milgram's obedient teachers: situational cues inform inferences about motives and traits.

    Science.gov (United States)

    Reeder, Glenn D; Monroe, Andrew E; Pryor, John B

    2008-07-01

    The research investigated impressions formed of a "teacher" who obeyed an experimenter by delivering painful electric shocks to an innocent person (S. Milgram, 1963, 1974). Three findings emerged across different methodologies and different levels of experimenter-induced coercion. First, contrary to conventional wisdom, perceivers both recognized and appreciated situational forces, such as the experimenter's orders that prompted the aggression. Second, perceivers' explanations of the teacher's behavior focused on the motive of obedience (i.e., wanting to appease the experimenter) rather than on hurtful (or evil) motivation. Despite this overall pattern, perceptions of hurtful versus helpful motivation varied as a function of information regarding the level of coercion applied by the experimenter. Finally, theoretically important relationships were revealed among perceptions of situations, motives, and traits. In particular, situational cues (such as aspects of the experimenter's behavior) signaled the nature of the teacher's motives, which in turn informed inferences of the teacher's traits. Overall, the findings pose problems for the lay dispositionism perspective but fit well with multiple inference models of dispositional inference.

  14. Artificial cognitive memory—changing from density driven to functionality driven

    Science.gov (United States)

    Shi, L. P.; Yi, K. J.; Ramanathan, K.; Zhao, R.; Ning, N.; Ding, D.; Chong, T. C.

    2011-03-01

    Increasing density based on bit size reduction is currently a main driving force for the development of data storage technologies. However, it is expected that all of the current available storage technologies might approach their physical limits in around 15 to 20 years due to miniaturization. To further advance the storage technologies, it is required to explore a new development trend that is different from density driven. One possible direction is to derive insights from biological counterparts. Unlike physical memories that have a single function of data storage, human memory is versatile. It contributes to functions of data storage, information processing, and most importantly, cognitive functions such as adaptation, learning, perception, knowledge generation, etc. In this paper, a brief review of current data storage technologies are presented, followed by discussions of future storage technology development trend. We expect that the driving force will evolve from density to functionality, and new memory modules associated with additional functions other than only data storage will appear. As an initial step toward building a future generation memory technology, we propose Artificial Cognitive Memory (ACM), a memory based intelligent system. We also present the characteristics of ACM, new technologies that can be used to develop ACM components such as bioinspired element cells (silicon, memristor, phase change, etc.), and possible methodologies to construct a biologically inspired hierarchical system.

  15. On the Anisotropic Nature of MRI-driven Turbulence in Astrophysical Disks

    DEFF Research Database (Denmark)

    Murphy, Gareth; Pessah, Martin E.

    2015-01-01

    -periodic way on timescales comparable to ∼10 inverse angular frequencies, motivating the temporal analysis of its anisotropy. We introduce a 3D tensor invariant analysis to quantify and classify the evolution of the anisotropy of the turbulent flow. This analysis shows a continuous high level of anisotropy......, with brief sporadic transitions toward two- and three-component isotropic turbulent flow. This temporal-dependent anisotropy renders standard shell averaging especially when used simultaneously with long temporal averages, inadequate for characterizing MRI-driven turbulence. We propose an alternative way...

  16. Nonequilibrium Thermodynamics of Driven Disordered Materials

    Science.gov (United States)

    Bouchbinder, Eran

    2011-03-01

    We present a nonequilibrium thermodynamic framework for describing the dynamics of driven disordered solids (noncrystalline solids near and below their glass temperature, soft glassy materials such as colloidal suspensions and heavily dislocated polycrystalline solids). A central idea in our approach is that the set of mechanically stable configurations, i.e. the part of the system that is described by inherent structures, evolves slowly as compared to thermal vibrations and is characterized by an effective disorder temperature. Our thermodynamics-motivated equations of motion for the flow of energy and entropy are supplemented by coarse-grained internal variables that carry information about the relevant microscopic physics. Applications of this framework to amorphous visco-plasticity (Shear-Transformation-Zone theory), glassy memory effects (the Kovacs effect) and dislocation-mediated polycrystalline plasticity will be briefly discussed.

  17. Public Service Motivation and Monetary Incentives: Substitutes or Motivation Crowding?

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2011-01-01

    Motivation is probably one of the most important determinants for organizational performance, because it stimulates effort and effective behaviors among people in the organization. But what type of motivation should public managers rely on? The PSM literature has argued that public service...... motivation is the most important type of motivation in the delivery of public service, because it substitutes for egoistic motivation. Organizations whose members have high levels of PSM are therefore expected to be less dependent on utilitarian motivators such as monetary incentives. Motivation crowding...... theory, on the other hand, argues that the relationship is opposite, so it is the degree of incentives that affects motivation. Both arguments lead to expectations of an association between public service motivation and monetary incentives, but so far this complex relationship has not been entangled...

  18. Effectiveness of User- and Expert-Driven Web-based Hypertension Programs: an RCT.

    Science.gov (United States)

    Liu, Sam; Brooks, Dina; Thomas, Scott G; Eysenbach, Gunther; Nolan, Robert P

    2018-04-01

    advisable to incorporate an expert-driven e-counseling protocol in order to accommodate participants with greater motivation to change their lifestyle behaviors, but more studies are needed. This study is registered at www.clinicaltrials.gov NCT03111836. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  19. Laser-Driven Mini-Thrusters

    International Nuclear Information System (INIS)

    Sterling, Enrique; Lin Jun; Sinko, John; Kodgis, Lisa; Porter, Simon; Pakhomov, Andrew V.; Larson, C. William; Mead, Franklin B. Jr.

    2006-01-01

    Laser-driven mini-thrusters were studied using Delrin registered and PVC (Delrin registered is a registered trademark of DuPont) as propellants. TEA CO2 laser (λ = 10.6 μm) was used as a driving laser. Coupling coefficients were deduced from two independent techniques: force-time curves measured with a piezoelectric sensor and ballistic pendulum. Time-resolved ICCD images of the expanding plasma and combustion products were analyzed in order to determine the main process that generates the thrust. The measurements were also performed in a nitrogen atmosphere in order to test the combustion effects on thrust. A pinhole transmission experiment was performed for the study of the cut-off time when the ablation/air breakdown plasma becomes opaque to the incoming laser pulse

  20. Laser-Driven Mini-Thrusters

    Science.gov (United States)

    Sterling, Enrique; Lin, Jun; Sinko, John; Kodgis, Lisa; Porter, Simon; Pakhomov, Andrew V.; Larson, C. William; Mead, Franklin B.

    2006-05-01

    Laser-driven mini-thrusters were studied using Delrin® and PVC (Delrin® is a registered trademark of DuPont) as propellants. TEA CO2 laser (λ = 10.6 μm) was used as a driving laser. Coupling coefficients were deduced from two independent techniques: force-time curves measured with a piezoelectric sensor and ballistic pendulum. Time-resolved ICCD images of the expanding plasma and combustion products were analyzed in order to determine the main process that generates the thrust. The measurements were also performed in a nitrogen atmosphere in order to test the combustion effects on thrust. A pinhole transmission experiment was performed for the study of the cut-off time when the ablation/air breakdown plasma becomes opaque to the incoming laser pulse.

  1. Low uptake of influenza vaccine among university students: evaluating predictors beyond cost and safety concerns.

    Science.gov (United States)

    Bednarczyk, Robert A; Chu, Samantha L; Sickler, Heather; Shaw, Jana; Nadeau, Jessica A; McNutt, Louise-Anne

    2015-03-30

    Annual influenza vaccine coverage for young adults (including college students) remains low, despite a 2011 US recommendation for annual immunization of all people 6 months and older. College students are at high risk for influenza morbidity given close living and social spaces and extended travel during semester breaks when influenza circulation typically increases. We evaluated influenza vaccine uptake following an on-campus vaccine campaign at a large, public New York State university. Consecutive students visiting the University Health Center were recruited for a self-administered, anonymous, written survey. Students were asked about recent influenza vaccination, barriers to influenza vaccination, and willingness to get vaccinated to protect other vulnerable individuals they may encounter. Frequencies and proportions were evaluated. Of 653 students approached, 600 completed surveys (92% response proportion); respondents were primarily female (61%) and non-Hispanic white (59%). Influenza vaccine coverage was low (28%). Compared to coverage among non-Hispanic white students (30%), coverage was similar among Hispanic (30%) and other race/ethnicity students (28%) and lowest among non-Hispanic black students (17%). Among the unvaccinated, the most commonly selected vaccination barriers were "Too lazy to get the vaccine" (32%) and "Don't need the vaccine because I'm healthy" (29%); 6% of unvaccinated students cited cost as a barrier. After being informed that influenza vaccination of young, healthy people can protect other vulnerable individuals (e.g., infants, elderly), 71% of unvaccinated students indicated this would increase their willingness to get vaccinated. Influenza vaccine uptake among college students is very low. While making vaccine easily obtained may increase vaccine uptake, college students need to be motivated to get vaccinated. Typically healthy students may not perceive a need for influenza vaccine. Education about vaccinating healthy individuals

  2. Iranian Women’s Motivations for Seeking Health Information: A Qualitative Study

    Directory of Open Access Journals (Sweden)

    Nikbakht Nasrabadi

    2015-10-01

    Full Text Available Background Today empowerment of women by health literacy has become a necessity. Researchers have shown that women are active seekers of health information and seeking behaviors are driven by various motivational factors. Paying attention to women’s motivations for seeking health information could facilitate evidence-based policy making in promotion of public health literacy. As health information seeking develops within personal-social interactions and also the health system context, it seems that a qualitative paradigm is appropriate for studies in this field. Objectives The aim of this study was to explore Iranian women’s motivations for seeking heath information. Patients and Methods In this qualitative content analysis study, data collection was conducted considering the inclusion criteria, through purposive sampling and by semi-structured interviews with 17 women, using documentation and field notes, until data saturation. Qualitative data analysis was done constantly and simultaneous with data collection. Results Five central themes emerged to explain the women’s motivation for health information seeking including: a dealing with fear and uncertainly b understanding the nature of disease and diagnostic/therapeutic procedures c performing parental duties d promoting a healthy life style e receiving safer health care. Conclusions It seemed that respecting client’s concerns, providing comprehensive health information, as well as risk management and promoting safer health care is necessary.

  3. New Solutions to Line-Driven Winds of Hot Massive Stars

    Science.gov (United States)

    Gormaz-Matamala, Alex C.; Curé, Michel; Cidale, Lydia; Venero, Roberto

    2017-11-01

    In the frame of radiation driven wind theory (Castor et al.1975), we present self-consistent hydrodynamical solutions to the line-force parameters (k, α, δ) under LTE conditions. Hydrodynamic models are provided by HydWind (Curé 2004). We evaluate these results with those ones previously found in literature, focusing in different regions of the optical depth to be used to perform the calculations. The values for mass-loss rate and terminal velocity obtained from our calculations are also presented. We also examine the line-force parameters for the case when large changes in ionization throughout the wind occurs (δ-slow solutions, Curé et al.2011).

  4. Speed of the bacterial flagellar motor near zero load depends on the number of stator units.

    Science.gov (United States)

    Nord, Ashley L; Sowa, Yoshiyuki; Steel, Bradley C; Lo, Chien-Jung; Berry, Richard M

    2017-10-31

    The bacterial flagellar motor (BFM) rotates hundreds of times per second to propel bacteria driven by an electrochemical ion gradient. The motor consists of a rotor 50 nm in diameter surrounded by up to 11 ion-conducting stator units, which exchange between motors and a membrane-bound pool. Measurements of the torque-speed relationship guide the development of models of the motor mechanism. In contrast to previous reports that speed near zero torque is independent of the number of stator units, we observe multiple speeds that we attribute to different numbers of units near zero torque in both Na + - and H + -driven motors. We measure the full torque-speed relationship of one and two H + units in Escherichia coli by selecting the number of H + units and controlling the number of Na + units in hybrid motors. These experiments confirm that speed near zero torque in H + -driven motors increases with the stator number. We also measured 75 torque-speed curves for Na + -driven chimeric motors at different ion-motive force and stator number. Torque and speed were proportional to ion-motive force and number of stator units at all loads, allowing all 77 measured torque-speed curves to be collapsed onto a single curve by simple rescaling. Published under the PNAS license.

  5. Zero curvature-surface driven small objects

    Science.gov (United States)

    Dou, Xiaoxiao; Li, Shanpeng; Liu, Jianlin

    2017-08-01

    In this study, we investigate the spontaneous migration of small objects driven by surface tension on a catenoid, formed by a layer of soap constrained by two rings. Although the average curvature of the catenoid is zero at each point, the small objects always migrate to the position near the ring. The force and energy analyses have been performed to uncover the mechanism, and it is found that the small objects distort the local shape of the liquid film, thus making the whole system energetically favorable. These findings provide some inspiration to design microfluidics, aquatic robotics, and miniature boats.

  6. Optimal Orientation Planning and Control Deviation Estimation on FAST Cable-Driven Parallel Robot

    Directory of Open Access Journals (Sweden)

    Hui Li

    2014-03-01

    Full Text Available The paper is devoted theoretically to the optimal orientation planning and control deviation estimation of FAST cable-driven parallel robot. Regarding the robot characteristics, the solutions are obtained from two constrained optimizations, both of which are based on the equilibrium of the cabin and the attention on force allocation among 6 cable tensions. A kind of control algorithm is proposed based on the position and force feedbacks. The analysis proves that the orientation control depends on force feedback and the optimal tension solution corresponding to the planned orientation. Finally, the estimation of orientation deviation is given under the limit range of tension errors.

  7. Convectively driven decadal zonal accelerations in Earth's fluid core

    Science.gov (United States)

    More, Colin; Dumberry, Mathieu

    2018-04-01

    Azimuthal accelerations of cylindrical surfaces co-axial with the rotation axis have been inferred to exist in Earth's fluid core on the basis of magnetic field observations and changes in the length-of-day. These accelerations have a typical timescale of decades. However, the physical mechanism causing the accelerations is not well understood. Scaling arguments suggest that the leading order torque averaged over cylindrical surfaces should arise from the Lorentz force. Decadal fluctuations in the magnetic field inside the core, driven by convective flows, could then force decadal changes in the Lorentz torque and generate zonal accelerations. We test this hypothesis by constructing a quasi-geostrophic model of magnetoconvection, with thermally driven flows perturbing a steady, imposed background magnetic field. We show that when the Alfvén number in our model is similar to that in Earth's fluid core, temporal fluctuations in the torque balance are dominated by the Lorentz torque, with the latter generating mean zonal accelerations. Our model reproduces both fast, free Alfvén waves and slow, forced accelerations, with ratios of relative strength and relative timescale similar to those inferred for the Earth's core. The temporal changes in the magnetic field which drive the time-varying Lorentz torque are produced by the underlying convective flows, shearing and advecting the magnetic field on a timescale associated with convective eddies. Our results support the hypothesis that temporal changes in the magnetic field deep inside Earth's fluid core drive the observed decadal zonal accelerations of cylindrical surfaces through the Lorentz torque.

  8. Anxiety and Threat-Related Attention: Cognitive-Motivational Framework and Treatment.

    Science.gov (United States)

    Mogg, Karin; Bradley, Brendan P

    2018-03-01

    Research in experimental psychopathology and cognitive theories of anxiety highlight threat-related attention biases (ABs) and underpin the development of a computer-delivered treatment for anxiety disorders: attention-bias modification (ABM) training. Variable effects of ABM training on anxiety and ABs generate conflicting research recommendations, novel ABM training procedures, and theoretical controversy. This article summarises an updated cognitive-motivational framework, integrating proposals from cognitive models of anxiety and attention, as well as evidence of ABs. Interactions between motivational salience-driven and goal-directed influences on multiple cognitive processes (e.g., stimulus evaluation, inhibition, switching, orienting) underlie anxiety and the variable manifestations of ABs (orienting towards and away from threat; threat-distractor interference). This theoretical analysis also considers ABM training as cognitive skill training, describes a conceptual framework for evaluating/developing novel ABM training procedures, and complements network-based research on reciprocal anxiety-cognition relationships. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Evaluating motives: Two simple tests to identify and avoid entanglement in legally dubious urine drug testing schemes.

    Science.gov (United States)

    Barnes, Michael C; Worthy, Stacey L

    2015-01-01

    This article educates healthcare practitioners on the legal framework prohibiting abusive practices in urine drug testing (UDT) in medical settings, discusses several profit-driven UDT schemes that have resulted in enforcement actions, and provides recommendations for best practices in UDT to comply with state and federal fraud and anti-kickback statutes. The authors carefully reviewed and analyzed statutes, regulations, adivsory opinions, case law, court documents, articles from legal journals, and news articles. Certain facts-driven UDT arrangements tend to violate federal and state healthcare laws and regulations, including Stark law, the anti-kickback statute, the criminal health care fraud statute, and the False Claims Act. Healthcare practitioners who use UDT can help ensure that they are in compliance with applicable federal and state laws by evaluating whether their actions are motivated by providing proper care to their patients rather than by profits. They must avoid schemes that violate the spirit of the law while appearing to comply with the letter of the law. Such a simple self-evaluation of motive can reduce a practitioner's likelihood of civil fines and criminal liability.

  10. An accurate tangential force-displacement model for granular-flow simulations: Contacting spheres with plastic deformation, force-driven formulation

    International Nuclear Information System (INIS)

    Vu-Quoc, L.; Lesburg, L.; Zhang, X.

    2004-01-01

    An elasto-plastic frictional tangential force-displacement (TFD) model for spheres in contact for accurate and efficient granular-flow simulations is presented in this paper; the present TFD is consistent with the elasto-plastic normal force-displacement (NFD) model presented in [ASME Journal of Applied Mechanics 67 (2) (2000) 363; Proceedings of the Royal Society of London, Series A 455 (1991) (1999) 4013]. The proposed elasto-plastic frictional TFD model is accurate, and is validated against non-linear finite-element analyses involving plastic flows under both loading and unloading conditions. The novelty of the present TFD model lies in (i) the additive decomposition of the elasto-plastic contact area radius into an elastic part and a plastic part, (ii) the correction of the particles' radii at the contact point, and (iii) the correction of the particles' elastic moduli. The correction of the contact-area radius represents an effect of plastic deformation in colliding particles; the correction of the radius of curvature represents a permanent indentation after impact; the correction of the elastic moduli represents a softening of the material due to plastic flow. The construction of both the present elasto-plastic frictional TFD model and its consistent companion, the elasto-plastic NFD model, parallels the formalism of the continuum theory of elasto-plasticity. Both NFD and TFD models form a coherent set of force-displacement (FD) models not available hitherto for granular-flow simulations, and are consistent with the Hertz, Cattaneo, Mindlin, Deresiewicz contact mechanics theory. Together, these FD models will allow for efficient simulations of granular flows (or granular gases) involving a large number of particles

  11. Radiation reaction effect on laser driven auto-resonant particle acceleration

    International Nuclear Information System (INIS)

    Sagar, Vikram; Sengupta, Sudip; Kaw, P. K.

    2015-01-01

    The effects of radiation reaction force on laser driven auto-resonant particle acceleration scheme are studied using Landau-Lifshitz equation of motion. These studies are carried out for both linear and circularly polarized laser fields in the presence of static axial magnetic field. From the parametric study, a radiation reaction dominated region has been identified in which the particle dynamics is greatly effected by this force. In the radiation reaction dominated region, the two significant effects on particle dynamics are seen, viz., (1) saturation in energy gain by the initially resonant particle and (2) net energy gain by an initially non-resonant particle which is caused due to resonance broadening. It has been further shown that with the relaxation of resonance condition and with optimum choice of parameters, this scheme may become competitive with the other present-day laser driven particle acceleration schemes. The quantum corrections to the Landau-Lifshitz equation of motion have also been taken into account. The difference in the energy gain estimates of the particle by the quantum corrected and classical Landau-Lifshitz equation is found to be insignificant for the present day as well as upcoming laser facilities

  12. A Preliminary Study of Classroom Motivators and De-Motivators from a Motivation-Hygiene Perspective

    Science.gov (United States)

    Katt, James A.; Condly, Steven J.

    2009-01-01

    This study seeks to begin answering two simple questions: "What motivates our students?" and its corollary, "What prevents our students from being motivated?" The motivation-hygiene theory (F. Herzberg, "Work and the nature of man," World Publishing, Cleveland, OH, 1966), a well-tested theory from organizational…

  13. Motivated Explanation

    Directory of Open Access Journals (Sweden)

    Richard ePatterson

    2015-10-01

    Full Text Available Although motivation is a well-established field of study in its own right, and has been fruitfully studied in connection with attribution theory and belief formation under the heading of motivated thinking, its powerful and pervasive influence on explanatory processes is less well explored. Where one has a strong motivation to understand some event correctly, one is thereby motivated to adhere as best one can to normative or epistemic criteria for correct or accurate explanation, even if one does not consciously formulate or apply such criteria. By contrast, many of our motivations to explain introduce bias into the processes involved in generating, evaluating, or giving of explanations. Non-epistemic explanatory motivations, or (following Kunda’s usage, directional motivations, include self-justification, resolution of cognitive dissonance, deliberate deception, teaching, and many more. Some of these motivations lead to the relaxation or violation of epistemic norms, combined with an effort to preserve the appearance of accuracy; others enhance epistemic motivation, so that one engages in more careful and thorough generational and evaluative processes. In short, real life explanatory processes are often constrained by multiple goals, epistemic and directional, where these goals may mutually reinforce one another or may conflict, and where our explanations emerge as a matter of weighing and satisfying those goals. Our proposals are largely programmatic, although we do review a good deal of relevant behavioral and neurological evidence. Specifically, we recognize five generative processes, some of which cover further sub-processes, and six evaluative processes. All of these are potential points of entry for the influence of motivation. We then suggest in some detail how specific sorts of explanatory motivation interact with specific explanatory processes.

  14. Cellular blebs: pressure-driven, axisymmetric, membrane protrusions

    KAUST Repository

    Woolley, Thomas E.

    2013-07-16

    Blebs are cellular protrusions that are used by cells for multiple purposes including locomotion. A mechanical model for the problem of pressure-driven blebs based on force and moment balances of an axisymmetric shell model is proposed. The formation of a bleb is initiated by weakening the shell over a small region, and the deformation of the cellular membrane from the cortex is obtained during inflation. However, simply weakening the shell leads to an area increase of more than 4 %, which is physically unrealistic. Thus, the model is extended to include a reconfiguration process that allows large blebs to form with small increases in area. It is observed that both geometric and biomechanical constraints are important in this process. In particular, it is shown that although blebs are driven by a pressure difference across the cellular membrane, it is not the limiting factor in determining bleb size. © 2013 Springer-Verlag Berlin Heidelberg.

  15. [Team motivation and motivational strategies adopted by nurses].

    Science.gov (United States)

    Bezerra, Felipa Daiana; Andrade, Marta Francisca da Conceição; Andrade, Joseilze Santos de; Vieira, Maria Jésia; Pimentel, Deborah

    2010-01-01

    Qualitative study held in an emergency hospital in Aracaju-SE, which aimed to know the perception of nurses about what is a motivated nursing team, to identify possible motivational policies used by them and if they are consistent with the policies proposed by Frederick Herzberg in his theory. Of the 20 nurses participants, the most understood the motivation as a set of techniques possible to shape the behavior of the individual at work, linking it to extrinsic factors and 60% did not consider his team motivated. The types of motivational policies that usually apply realized that these correspond to intrinsic factors aimed at self recovery and self realization of individuals in the tasks running.

  16. First Numerical Simulations of Turbulent Dynamos Driven by Libration, Precession and Tides in Triaxial Ellipsoids - An Alternative Route for Planetary Magnetism

    Science.gov (United States)

    Le Bars, M.; Kanuganti, S. R.; Favier, B.

    2017-12-01

    Most of the time, planetary dynamos are - tacitly or not - associated with thermo-solutal convection. The convective dynamo model has indeed proven successful to explain the current Earth's magnetic field. However, its results are sometimes difficult to reconcile with observational data and its validity can be questioned for several celestial bodies. For instance, the small size of the Moon and Ganymede makes it difficult to maintain a sufficient temperature gradient to sustain convection and to explain their past and present magnetic fields, respectively. The same caveat applies to the growing number of planetesimals shown to have generated magnetic fields in their early history. Finally, the energy budget of the early Earth is difficult to reconcile with a convective dynamo before the onset of inner core growth. Significant effort has thus been put into finding new routes for planetary dynamo. In particular, the rotational dynamics of planets, moons and small bodies, where their average spinning motion is periodically perturbed by the small mechanical forcings of libration, precession and/or tides, is now widely accepted as an efficient source of core turbulence. The underlying mechanism relies on a parametric instability where the inertial waves of the rotating fluid core are resonantly excited by the small forcing, leading to exponential growth and bulk filling intense motions, pumping their energy from the orbital dynamics. Dynamos driven by mechanical forcing have been suggested for the Moon, Mars, Io, the early Earth, etc. However, the real dynamo capacity of the corresponding flows has up-to-now been studied only in very limited cases, with simplified spherical/spheroidal geometries and/or overly viscous fluids. We will present here the first numerical simulations of dynamos driven by libration, precession and tides, in the triaxial ellipsoidal geometry and in the turbulent regime relevant for planetary cores. We will describe the numerical techniques

  17. Asymptotic work distributions in driven bistable systems

    International Nuclear Information System (INIS)

    Nickelsen, D; Engel, A

    2012-01-01

    The asymptotic tails of the probability distributions of thermodynamic quantities convey important information about the physics of nanoscopic systems driven out of equilibrium. We apply a recently proposed method to analytically determine the asymptotics of work distributions in Langevin systems to an one-dimensional model of single-molecule force spectroscopy. The results are in excellent agreement with numerical simulations, even in the centre of the distributions. We compare our findings with a recent proposal for an universal form of the asymptotics of work distributions in single-molecule experiments.

  18. Motivational Climate, Staff and Members' Behaviors, and Members' Psychological Well-Being at a National Fitness Franchise

    Science.gov (United States)

    Brown, Theresa C.; Fry, Mary D.

    2014-01-01

    Purpose: The purpose of this study was to examine the association between members' perceptions of staff's behaviors, motivational climate, their own behaviors, commitment to future exercise, and life satisfaction in a group-fitness setting. The theory-driven hypothesized mediating role of perceptions of the climate was also tested.…

  19. Report on results of R and D of coal liquefaction technology under Sunshine Project in fiscal 1981 (development of motive force recovery system by hydrohoist); 1981 nendo sekitan ekika gijutsu no kenkyu kaihatsu, chokusetsu suiten ekika plant no kaihatsu seika hokokusho. Hydrohoist ni yoru doryoku kaishu system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-03-01

    This paper explains the results of development of a hydrohoist system in a direct hydro-liquefaction plant under the Sunshine Project in fiscal 1981. Coal liquefaction deals with three phases of gas, liquid and solid at high pressures of 100-300 kg/cm{sup 2}. Slurry consisting of coal, catalyst and solvent is once fed into a supply chamber by a low pressure slurry pump. A high pressure slurry formed in a liquefaction reactor, after the separation of gaseous object, is boosted by a booster pump and force-fitted into the supply chamber from the above, discharging the slurry in the chamber to the high pressure reactor side. Since the high pressure product is used as the driving liquid, a force-feeding motive force can be greatly curtailed. It is a motive force recovery type hydrohoist. The product slurry in the supply chamber is discharged from a valve in the upper part; with the inner pressure going down quickly, the discharge valve wears very little. The basic experimental equipment was manufactured in fiscal 1980, with a test research conducted using the improved main equipment in fiscal 1981, and with the conceptual design of the hydrohoist also implemented on the assumption that it was applied to a pilot plant. (NEDO)

  20. The justice motive: where social psychologists found it, how they lost it, and why they may not find it again.

    Science.gov (United States)

    Lerner, Melvin J

    2003-01-01

    Beginning shortly after the 2nd World War, 3 lines of research associated with relative deprivation, equity theory, and just world contributed to the description of the influence of the justice motive in people's lives. By the late 1960s, these converging lines of research had documented the importance of people's desire for justice; nevertheless, contemporary social psychologists typically portray this justice-driven motivation as simply a manifestation of self-interest. The explanation for this failure to recognize a distinct and important justice motive points to the widespread reliance on research methods that elicit the participant's thoughtfully constructed narratives or role-playing responses. According to recent theoretical advances, these methods generate responses that reflect normative expectations of rational self-interest, and fail to capture the important effects of the emotionally generated imperatives of the justice motive.