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Sample records for asymmetrically directed behaviors

  1. Hypolocomotion, asymmetrically directed behaviors (licking, lifting, flinching, and shaking and dynamic weight bearing (gait changes are not measures of neuropathic pain in mice

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    Schorscher-Petcu Ara

    2010-06-01

    Full Text Available Abstract Background Spontaneous (non-evoked pain is a major clinical symptom of neuropathic syndromes, one that is understudied in basic pain research for practical reasons and because of a lack of consensus over precisely which behaviors reflect spontaneous pain in laboratory animals. It is commonly asserted that rodents experiencing pain in a hind limb exhibit hypolocomotion and decreased rearing, engage in both reflexive and organized limb directed behaviors, and avoid supporting their body weight on the affected side. Furthermore, it is assumed that the extent of these positive or negative behaviors can be used as a dependent measure of spontaneous chronic pain severity in such animals. In the present study, we tested these assumptions via blinded, systematic observation of digital video of mice with nerve injuries (chronic constriction or spared nerve injury, and automated assessment of locomotor behavior using photocell detection and dynamic weight bearing (i.e., gait using the CatWalk® system. Results We found no deficits in locomotor activity or rearing associated with neuropathic injury. The frequency of asymmetric (ipsilaterally directed behaviors were too rare to be seriously considered as representing spontaneous pain, and in any case did not statistically exceed what was blindly observed on the contralateral hind paw and in control (sham operated and unoperated mice. Changes in dynamic weight bearing, on the other hand, were robust and ipsilateral after spared nerve injury (but not chronic constriction injury. However, we observed timing, pharmacological, and genetic dissociation of mechanical allodynia and gait alterations. Conclusions We conclude that spontaneous neuropathic pain in mice cannot be assessed using any of these measures, and thus caution is warranted in making such assertions.

  2. The Asymmetric Active Coupler: Stable Nonlinear Supermodes and Directed Transport

    CERN Document Server

    Kominis, Yannis; Flach, Sergej

    2016-01-01

    We consider the asymmetric active coupler (AAC) consisting of two coupled dissimilar waveguides with gain and loss. We show that under generic conditions, not restricted by parity-time symmetry, there exist finite-power, constant-intensity nonlinear supermodes (NS), resulting from the balance between gain, loss, nonlinearity, coupling and dissimilarity. The system is shown to possess nonreciprocal dynamics enabling directed power transport and optical isolation functionality.

  3. Direct Catalytic Asymmetric Mannich-Type Reaction of Alkylamides.

    Science.gov (United States)

    Arteaga, Fernando Arteaga; Liu, Zijian; Brewitz, Lennart; Chen, Jianyang; Sun, Bo; Kumagai, Naoya; Shibasaki, Masakatsu

    2016-05-20

    Direct enolate formation coupled with subsequent enantioselective C-C bond formation remains a topic of intense interest in asymmetric catalysis. This methodology is achieved even with low acidic amides without an electron-withdrawing group at the α-position in the context of a Mannich-type reaction. Acetate-, propionate-, and butyrate-type 7-azaindoline amides served as enolate precursors to afford the desired Mannich adducts with high stereoselectivity, and ligand-enabled diastereo-divergency provided access to both anti/syn diastereomers. The facile transformation of the amide moiety ensures the synthetic utility of the Mannich adducts.

  4. Direct asymmetric aldol reactions catalyzed by lipase from porcine pancreas.

    Science.gov (United States)

    Zheng, Jing; Xie, Bang-Hua; Chen, Yan-Li; Cao, Jian-Fei; Yang, Yang; Guan, Zhi; He, Yan-Hong

    2014-01-01

    Porcine pancreas lipase type II (PPL II) exhibited unnatural catalytic activity in direct asymmetric aldol reactions between cyclic ketones and aromatic or heteroaromatic aldehydes in acetonitrile in the presence of phosphate buffer. A wide range of substrates was accepted by the enzyme to afford the corresponding aldol products in low to high yields (10-98%), with moderate to excellent enantioselectivities (53-94% ee, for anti-isomers) and low to moderate diastereoselectivities (48/52-87/13 dr, anti/syn). This methodology expands the application of PPL II, and it might be developed into a potentially valuable method for sustainable organic synthesis.

  5. Impact and Use of the Asymmetric Property in Bi-directional Cooperative Relaying under Asymmetric Traffic Conditions

    Science.gov (United States)

    Saeki, Takaaki; Yamamoto, Koji; Murata, Hidekazu; Yoshida, Susumu

    Cooperative relaying (CR) is a promising technique to provide spatial diversity by combining multiple signals from source and relay stations. In the present paper, the impact and use of the asymmetric property in bi-directional CR under asymmetric traffic conditions are discussed assuming that CR involves one communication pair and one relay station in a time division duplex (TDD) system. The asymmetric property means that the average communication quality differs for each transmission direction because of the difference in signal power between the combined signals for each direction. First, numerical results show the asymmetric property of bi-directional CR. Next, in order to evaluate the impact of the asymmetric property, the optimal relay position and resource allocation are compared to those in simple multi-hop relaying, which does not have the asymmetric property. Numerical results show that, in order to maximize the overall quality of bi-directional communication, the optimal relay position in CR depends on the offered traffic ratio, which is defined as the traffic ratio of each transmission direction, while the offered traffic ratio does not affect the optimal relay position in multi-hop relaying. Finally, the asymmetric property is used to enhance the overall quality. Specifically, a high overall quality can be achieved by, for example, opportunistically switching to the transmission direction with higher quality. Under asymmetric traffic conditions, weighted proportionally fair scheduling (WPFS), which is proposed in the context of downlink scheduling in a cellular network, is applied to transmission direction switching. Numerical results reveal that WPFS provides a high overall quality and that the quality ratio is similar to the offered traffic ratio.

  6. Keep-Left Behavior Induced by Asymmetrically Profiled Walls

    Science.gov (United States)

    Oliveira, C. L. N.; Vieira, A. P.; Helbing, D.; Andrade, J. S.; Herrmann, H. J.

    2016-01-01

    We show, computationally and analytically, that asymmetrically shaped walls can organize the flow of pedestrians driven in opposite directions through a corridor. Precisely, a two-lane ordered state emerges in which people always walk on the left-hand side (or right-hand side), controlled by the system's parameters. This effect depends on features of the channel geometry, such as the asymmetry of the profile and the channel width, as well as on the density and the drift velocity of pedestrians, and the intensity of noise. We investigate in detail the influence of these parameters on the flow and discover a crossover between ordered and disordered states. Our results show that an ordered state only appears within a limited range of drift velocities. Moreover, increasing noise may suppress such flow organization, but the flow is always sustained. This is in contrast with the "freezing by heating" phenomenon according to which pedestrians tend to clog in smooth channels for strong noise [Phys. Rev. Lett. 84, 1240 (2000)]. Therefore, the ratchetlike effect proposed here acts on the system not only to induce a "keep-left" behavior but also to prevent the freezing by heating clogging phenomenon. Besides pedestrian flow, this new phenomenon has other potential applications in microfluidics systems.

  7. The Effect of Labor Supply Shortages on Asymmetric Cost Behavior

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    This study examines the effect of shortages in labor supply on asymmetric cost behavior. Building on the labor demand literature, it is argued that labor supply shortages increase adjustment costs for hiring new employees. Consistent with this explanation, results provide evidence that companies...... facing restrictions in labor supply increase costs (and resources) less than companies operating with sufficient access to additional personnel. This leads to a more symmetrical cost behavior for increasing activity compared to decreasing activity. Additional analyses show that shortages in labor supply...... induce firms to increase selling prices but also to temporarily expect more effort from their current employees. The effect decreases with the length of the labor supply shock and is more pronounced for companies located in less populated regions. Results are robust to alternative explanations...

  8. Directed Orientation of Asymmetric Composite Dumbbells by Electric Field Induced Assembly

    NARCIS (Netherlands)

    Nagao, D.; Sugimoto, M.; Okada, A.; Ishii, H.; Konno, M.; Imhof, A.; van Blaaderen, A.

    2012-01-01

    Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells,

  9. Directed Orientation of Asymmetric Composite Dumbbells by Electric Field Induced Assembly

    NARCIS (Netherlands)

    Nagao, D.; Sugimoto, M.; Okada, A.; Ishii, H.; Konno, M.; Imhof, A.; van Blaaderen, A.

    2012-01-01

    Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells, w

  10. Asymmetric multiscale behavior in PM2.5 time series: Based on asymmetric MS-DFA

    Science.gov (United States)

    Zhang, Chen; Ni, Zhiwei; Ni, Liping

    2016-11-01

    Particulate matter with an aerodynamic diameter of 2.5 mm or less (PM2.5) is one of the most serious air pollution, considered most harmful for people by World Health Organisation. In this paper, we utilized the asymmetric multiscale detrended fluctuation analysis (A-MSDFA) method to explore the existence of asymmetric correlation properties for PM2.5 daily average concentration in two USA cities (Fresno and Los Angeles) and two Chinese cities (Hong Kong and Shanghai), and to assess the properties of these asymmetric correlations. The results show the existences of asymmetric correlations, and the degree of asymmetric for two USA cities is stronger than that of two Chinese cities. Further, most of the local exponent β(n) are smaller than 0.5, which indicates the existence of anti-persistent long-range correlation for PM2.5 time series in four cities. In addition, we reanalyze the asymmetric correlation by the A-MSDFA method with secant rolling windows of different sizes, which can investigate dynamic changes in the multiscale correlation for PM2.5 time series with changing window size. Whatever window sizes, the correlations are asymmetric and display smaller asymmetries at small scales and larger asymmetries at large scales. Moreover, the asymmetries become increasingly weaker with the increase of window sizes.

  11. Direct asymmetric aldol reaction using MBHA resin-supported peptide containing L-proline unit

    Institute of Scientific and Technical Information of China (English)

    Liang Zhang; Wen Bo Ding; Yong Ping Yu; Hong Bin Zou

    2009-01-01

    MBHA resin-supported tripeptide catalyst system containing L-proline unit has been developed for use in the direct asymmetric aldol reaction of acetone and aldehydes,which afford the corresponding products with satisfactory isolated yields and enantiomeric excesses.

  12. Directional Notch trafficking in Sara endosomes during asymmetric cell division in the spinal cord.

    Science.gov (United States)

    Kressmann, Sabine; Campos, Claudia; Castanon, Irinka; Fürthauer, Maximilian; González-Gaitán, Marcos

    2015-03-01

    Asymmetric division of neural precursor cells contributes to the generation of a variety of neuronal types. Asymmetric division is mediated by the asymmetric inheritance of fate determinants by the two daughter cells. In vertebrates, asymmetric fate determinants, such as Par3 and Mib, are only now starting to be identified. Here we show that, during mitosis of neural precursors in zebrafish, directional trafficking of Sara endosomes to one of the daughters can function as such a determinant. In asymmetric lineages, where one daughter cell becomes a neuron (n cell) whereas the other divides again to give rise to two neurons (p cell), we found that the daughter that inherits most of the Sara endosomes acquires the p fate. Sara endosomes carry an endocytosed pool of the Notch ligand DeltaD, which is thereby itself distributed asymmetrically. Sara and Notch are both essential for cell fate assignation within asymmetric lineages. Therefore, the Sara endosome system determines the fate decision between neuronal differentiation and mitosis in asymmetric lineages and thereby contributes to controlling the number of neural precursors and differentiated neurons during neurogenesis in a vertebrate.

  13. Direct Asymmetric Aldol Type Reaction with Ethyl Diazoacetate: Stereoselective Synthesis of α, β-Dihydroxy Esters

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-Yi; YAO Wen-Gang; FENG Hai-Tao; WANG Jian-Bo

    2003-01-01

    @@ Enantioselective aldol condensation under catalytic condition remains a challenging task in modern organic synthesis, and numerous efforts have been directed to this area. In particular, the direct catalytic asymmetric aldol reaction is very attractive considering the requirement of atom efficiency. This has been studied only recently, and several very practical processes have been developed. We have recently initiated a study on the direct asymmetric aldol type reaction with ethyl diazoacetate as nucleophile. Moderate enantioselectivities (65% ~91% ee ) were achieved in the condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr (OBu- t )4. [1

  14. Hybrid Asymmetric Space Vector Modulation for inverter based direct torque control induction motor drive

    Directory of Open Access Journals (Sweden)

    Nandakumar Sundararaju

    2014-05-01

    Full Text Available This paper proposes novel hybrid asymmetric space vector modulation technique for inverter operated direct torque control induction motor drive. The hybridization process is performed by the combination of continuous asymmetric space vector modulation pulse width technique (ASVPWM and fuzzy operated discontinuous ASVPWM technique. Combination process is based on pulse mismatching technique. Pulse mismatching technique helps to reduce the active region of the switch. Finally, optimal pulses are applied to control the inverter. The optimal hybrid pulse condense switching losses of the inverter and also improves the operating performance of the direct torque control (DTC based drive system like smooth dynamic response in speed reversal, minimum torque error, settling time of speed. Simulation results of proposed hybrid asymmetric space vector pulse width modulation technique to direct torque control (HASVPWM-DTC approach has been carried out by using Matlab-Simulink environment.

  15. Unexpected phase behavior of an asymmetric diblock copolymer

    DEFF Research Database (Denmark)

    Papadakis, Christine Maria; Almdal, Kristoffer; Mortensen, Kell

    1999-01-01

    We report on measurements of the transmitted depolarized light intensity and on small-angle neutron scattering (SANS) measurements on a compositionally asymmetric poly(ethylene propylene)-poly(dimethylsiloxane) diblock copolymer studied in the bulk. SANS measurements were made both on isotropic a...

  16. The Behavior Of Asymmetric Frontal Couplings With Permanent Magnets In Magnetic Powder And High Temperature Environments

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    Ion DOBROTA

    2002-12-01

    Full Text Available The main purpose of this paper is the comparative analysis of the behavior of frontal couplings with Nd-Fe-B permanent magnets in difficult environments, specific to metallurgy – such as environments with magnetic powders and high temperature – in two constructive variants: symmetric couplings and asymmetric couplings (with divided poles. The results show the superior performance of asymmetric couplings under the given conditions

  17. Solitary Wave Generation from Constant Continuous Wave in Asymmetric Oppositely Directed Waveguide Coupler

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    Kazantseva E.V.

    2015-01-01

    Full Text Available In a model which describes asymmetric oppositely directed nonlinear coupler it was observed in numerical simulations a phenomenon of solitary wave generation from the input constant continuous wave set at the entrance of a waveguide with negative refraction. The period of solitary wave formation decreases with increase of the continuum wave amplitude.

  18. Zinc-prolinamide complex catalyzed direct asymmetric aldol reactions in the presence of water

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An efficient direct asymmetric aldol reaction with zinc triflate and prolinamides as combined catalysts is reported.A series of chiral prolinamides have been designed and used in the direct aldol reaction resulting in the desired products with excellent yields(up to 94% yield) and high enantioselectivities(up to 96% ee).Water was found to play a significant role in the formation of the aldol products,which suggests a new strategy in the design of new organic catalysts.

  19. Asymmetric Directional Multicast for Capillary Machine-to-Machine Using mmWave Communications.

    Science.gov (United States)

    Kwon, Jung-Hyok; Kim, Eui-Jik

    2016-01-01

    The huge demand for high data rate machine-to-machine (M2M) services has led to the use of millimeter Wave (mmWave) band communications with support for a multi-Gbps data rate through the use of directional antennas. However, unnecessary sector switching in multicast transmissions with directional antennas results in a long delay, and consequently a low throughput. We propose asymmetric directional multicast (ADM) for capillary M2M to address this problem in mmWave communications. ADM provides asymmetric sectorization that is optimized for the irregular deployment pattern of mulicast group members. In ADM, an M2M gateway builds up asymmetric sectors with a beamwidth of a different size to cover all multicast group members with the minimum number of directional transmissions. The performance of ADM under various simulation environments is evaluated through a comparison with legacy mmWave multicast. The results of the simulation indicate that ADM achieves a better performance in terms of the transmission sectors, the transmission time, and the aggregate throughput when compared with the legacy multicast method.

  20. Unihemispheric sleep and asymmetrical sleep: behavioral, neurophysiological, and functional perspectives

    OpenAIRE

    Mascetti GG

    2016-01-01

    Gian Gastone Mascetti Department of General Psychology, University of Padova, Padova, Italy Abstract: Sleep is a behavior characterized by a typical body posture, both eyes' closure, raised sensory threshold, distinctive electrographic signs, and a marked decrease of motor activity. In addition, sleep is a periodically necessary behavior and therefore, in the majority of animals, it involves the whole brain and body. However, certain marine mammals and species of birds show a differe...

  1. Asymmetric Catalysis with CO2 : The Direct α-Allylation of Ketones.

    Science.gov (United States)

    Pupo, Gabriele; Properzi, Roberta; List, Benjamin

    2016-05-10

    Quaternary stereocenters are found in numerous bioactive molecules. The Tsuji-Trost reaction has proven to be a powerful C-C bond forming process, and, at least in principle, should be well suited to access quaternary stereocenters via the α-allylation of ketones. However, while indirect approaches are known, the direct, catalytic asymmetric α-allylation of branched ketones has been elusive until today. By combining "enol catalysis" with the use of CO2 as a formal catalyst for asymmetric catalysis, we have now developed a solution to this problem: we report a direct, highly enantioselective and highly atom-economic Tsuji-Trost allylation of branched ketones with allylic alcohol. Our reaction delivers products bearing quaternary stereocenters with high enantioselectivity and water as the sole by-product. We expect our methodology to be of utility in asymmetric catalysis and inspire the design of other highly atom-economic transformations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Asymmetric counteranion-directed Lewis acid organocatalysis for the scalable cyanosilylation of aldehydes

    Science.gov (United States)

    Zhang, Zhipeng; Bae, Han Yong; Guin, Joyram; Rabalakos, Constantinos; van Gemmeren, Manuel; Leutzsch, Markus; Klussmann, Martin; List, Benjamin

    2016-08-01

    Due to the high versatility of chiral cyanohydrins, the catalytic asymmetric cyanation reaction of carbonyl compounds has attracted widespread interest. However, efficient protocols that function at a preparative scale with low catalyst loading are still rare. Here, asymmetric counteranion-directed Lewis acid organocatalysis proves to be remarkably successful in addressing this problem and enabled a molar-scale cyanosilylation in quantitative yield and with excellent enantioselectivity. Also, the catalyst loading could be lowered to a part-per-million level (50 ppm: 0.005 mol%). A readily accessible chiral disulfonimide was used, which in combination with trimethylsilyl cyanide, turned into the active silylium Lewis acid organocatalyst. The nature of a peculiar phenomenon referred to as a ``dormant period'', which is mainly induced by water, was systematically investigated by means of in situ Fourier transform infrared analysis.

  3. Improving atomic force microscopy imaging by a direct inverse asymmetric PI hysteresis model.

    Science.gov (United States)

    Wang, Dong; Yu, Peng; Wang, Feifei; Chan, Ho-Yin; Zhou, Lei; Dong, Zaili; Liu, Lianqing; Li, Wen Jung

    2015-02-03

    A modified Prandtl-Ishlinskii (PI) model, referred to as a direct inverse asymmetric PI (DIAPI) model in this paper, was implemented to reduce the displacement error between a predicted model and the actual trajectory of a piezoelectric actuator which is commonly found in AFM systems. Due to the nonlinearity of the piezoelectric actuator, the standard symmetric PI model cannot precisely describe the asymmetric motion of the actuator. In order to improve the accuracy of AFM scans, two series of slope parameters were introduced in the PI model to describe both the voltage-increase-loop (trace) and voltage-decrease-loop (retrace). A feedforward controller based on the DIAPI model was implemented to compensate hysteresis. Performance of the DIAPI model and the feedforward controller were validated by scanning micro-lenses and standard silicon grating using a custom-built AFM.

  4. Improving Atomic Force Microscopy Imaging by a Direct Inverse Asymmetric PI Hysteresis Model

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2015-02-01

    Full Text Available A modified Prandtl–Ishlinskii (PI model, referred to as a direct inverse asymmetric PI (DIAPI model in this paper, was implemented to reduce the displacement error between a predicted model and the actual trajectory of a piezoelectric actuator which is commonly found in AFM systems. Due to the nonlinearity of the piezoelectric actuator, the standard symmetric PI model cannot precisely describe the asymmetric motion of the actuator. In order to improve the accuracy of AFM scans, two series of slope parameters were introduced in the PI model to describe both the voltage-increase-loop (trace and voltage-decrease-loop (retrace. A feedforward controller based on the DIAPI model was implemented to compensate hysteresis. Performance of the DIAPI model and the feedforward controller were validated by scanning micro-lenses and standard silicon grating using a custom-built AFM.

  5. Unihemispheric sleep and asymmetrical sleep: behavioral, neurophysiological, and functional perspectives

    Directory of Open Access Journals (Sweden)

    Mascetti GG

    2016-07-01

    Full Text Available Gian Gastone Mascetti Department of General Psychology, University of Padova, Padova, Italy Abstract: Sleep is a behavior characterized by a typical body posture, both eyes' closure, raised sensory threshold, distinctive electrographic signs, and a marked decrease of motor activity. In addition, sleep is a periodically necessary behavior and therefore, in the majority of animals, it involves the whole brain and body. However, certain marine mammals and species of birds show a different sleep behavior, in which one cerebral hemisphere sleeps while the other is awake. In dolphins, eared seals, and manatees, unihemispheric sleep allows them to have the benefits of sleep, breathing, thermoregulation, and vigilance. In birds, antipredation vigilance is the main function of unihemispheric sleep, but in domestic chicks, it is also associated with brain lateralization or dominance in the control of behavior. Compared to bihemispheric sleep, unihemispheric sleep would mean a reduction of the time spent sleeping and of the associated recovery processes. However, the behavior and health of aquatic mammals and birds does not seem at all impaired by the reduction of sleep. The neural mechanisms of unihemispheric sleep are unknown, but assuming that the neural structures involved in sleep in cetaceans, seals, and birds are similar to those of terrestrial mammals, it is suggested that they involve the interaction of structures of the hypothalamus, basal forebrain, and brain stem. The neural mechanisms promoting wakefulness dominate one side of the brain, while those promoting sleep predominates the other side. For cetaceans, unihemispheric sleep is the only way to sleep, while in seals and birds, unihemispheric sleep events are intermingled with bihemispheric and rapid eye movement sleep events. Electroencephalogram hemispheric asymmetries are also reported during bihemispheric sleep, at awakening, and at sleep onset, as well as being associated with a use

  6. Unihemispheric sleep and asymmetrical sleep: behavioral, neurophysiological, and functional perspectives

    Science.gov (United States)

    Mascetti, Gian Gastone

    2016-01-01

    Sleep is a behavior characterized by a typical body posture, both eyes’ closure, raised sensory threshold, distinctive electrographic signs, and a marked decrease of motor activity. In addition, sleep is a periodically necessary behavior and therefore, in the majority of animals, it involves the whole brain and body. However, certain marine mammals and species of birds show a different sleep behavior, in which one cerebral hemisphere sleeps while the other is awake. In dolphins, eared seals, and manatees, unihemispheric sleep allows them to have the benefits of sleep, breathing, thermoregulation, and vigilance. In birds, antipredation vigilance is the main function of unihemispheric sleep, but in domestic chicks, it is also associated with brain lateralization or dominance in the control of behavior. Compared to bihemispheric sleep, unihemispheric sleep would mean a reduction of the time spent sleeping and of the associated recovery processes. However, the behavior and health of aquatic mammals and birds does not seem at all impaired by the reduction of sleep. The neural mechanisms of unihemispheric sleep are unknown, but assuming that the neural structures involved in sleep in cetaceans, seals, and birds are similar to those of terrestrial mammals, it is suggested that they involve the interaction of structures of the hypothalamus, basal forebrain, and brain stem. The neural mechanisms promoting wakefulness dominate one side of the brain, while those promoting sleep predominates the other side. For cetaceans, unihemispheric sleep is the only way to sleep, while in seals and birds, unihemispheric sleep events are intermingled with bihemispheric and rapid eye movement sleep events. Electroencephalogram hemispheric asymmetries are also reported during bihemispheric sleep, at awakening, and at sleep onset, as well as being associated with a use-dependent process (local sleep). PMID:27471418

  7. ESR Studies on the Micellization Behaviors of a Series of Novel Asymmetric Gemini Surfactants

    Institute of Scientific and Technical Information of China (English)

    WU,Yi-Tian(吴一天); WANG,Jin-Ben(王金本); LIU,Ming-Hua(刘鸣华); LIANG,Wen-Ping(梁文平)

    2002-01-01

    The synthesis of a new series of asymmetric cationic gemini surfactant and the investigation of their miccellization behaviors by electronic spin resonance (ESR) as well as the surface tension measurements were reported. 4-Oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (4-oxo-TEMPO) is used as the spin probe. The surfactants studied have the general formula [CnH2n+1 N+(CH3)2C6H12N+(CH3)2Cm H2m,1]Br2- , referred to as dimeric n-6-m surfactants, in which n and m are the numbers of carbon atoms in the asymmetric side alkyl chains. From the experimental data, rotational correlation time τc, surface tension and critical micelle concentration (cac) ,values, the physical properties of these new surfactants have preliminarily been evaluated. It is shown that this new series of asymmetric gmini surfactants has interesting micellization behaviors, and they are very different in aggregating tendency from their asymmetric analogues.

  8. Solitary wave generation from continuum in asymmetric oppositely directed nonlinear waveguide coupler

    Science.gov (United States)

    Kazantseva, E. V.; Maimistov, A. I.

    2016-08-01

    In a model which describes asymmetric oppositely directed nonlinear waveguide coupler it was observed in the numerical simulation a phenomenon of solitary wave formation from the input constant continuous wave set at the entrance of a waveguide with negative index of refraction. Threshold value of the amplitude of the constant continuous wave, which defines the condition of appearance of the first solitary wave, decreases with increasing of the parameter of nonlinearity. The period of solitary wave formation decreases with increasing of the continuum wave amplitude.

  9. Lepton-Flavored Asymmetric Dark Matter and Interference in Direct Detection

    CERN Document Server

    Hamze, Ali; Koeller, Jason; Trendafilova, Cynthia; Yu, Jiang-Hao

    2014-01-01

    In flavored dark matter models, dark matter can scatter off of nuclei through Higgs and photon exchange, both of which can arise from renormalizable interactions and individually lead to strong constraints from direct detection. While these two interaction channels can destructively interfere in the scattering amplitude, for a thermal relic with equal abundances for the dark matter particle and its antiparticle, this produces no effect on the total event rate. Focusing on lepton-flavored dark matter, we show that it is quite natural for dark matter to have become asymmetric during high-scale leptogenesis, and that in this case the direct detection bounds can be significantly weakened due to interference. We quantify this by mapping out and comparing the regions of parameter space that are excluded by direct detection for the symmetric and asymmetric cases of lepton-flavored dark matter. In particular, we show that the entire parameter region is ruled out for symmetric dark matter, while large portions of para...

  10. Asymmetric flexural behavior from bamboo's functionally graded hierarchical structure: underlying mechanisms.

    Science.gov (United States)

    Habibi, Meisam K; Samaei, Arash T; Gheshlaghi, Behnam; Lu, Jian; Lu, Yang

    2015-04-01

    As one of the most renewable resources on Earth, bamboo has recently attracted increasing interest for its promising applications in sustainable structural purposes. Its superior mechanical properties arising from the unique functionally-graded (FG) hierarchical structure also make bamboo an excellent candidate for bio-mimicking purposes in advanced material design. However, despite its well-documented, impressive mechanical characteristics, the intriguing asymmetry in flexural behavior of bamboo, alongside its underlying mechanisms, has not yet been fully understood. Here, we used multi-scale mechanical characterizations assisted with advanced environmental scanning electron microscopy (ESEM) to investigate the asymmetric flexural responses of natural bamboo (Phyllostachys edulis) strips under different loading configurations, during "elastic bending" and "fracture failure" stages, with their respective deformation mechanisms at microstructural level. Results showed that the gradient distribution of the vascular bundles along the thickness direction is mainly responsible for the exhibited asymmetry, whereas the hierarchical fiber/parenchyma cellular structure plays a critical role in alternating the dominant factors for determining the distinctly different failure mechanisms. A numerical model has been likewise adopted to validate the effective flexural moduli of bamboo strips as a function of their FG parameters, while additional experiments on uniaxial loading of bamboo specimens were performed to assess the tension-compression asymmetry, for further understanding of the microstructure evolution of bamboo's outer and innermost layers under different bending states. This work could provide insights to help the processing of novel bamboo-based composites and enable the bio-inspired design of advanced structural materials with desired flexural behavior.

  11. Optical diode behavior of photonic crystal structure with asymmetric Kerr defect

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted field are the same for the forward and backward operations. In the nonlinear case, however, the transmitted intensities are much different for the two operations, which display diode characteristic. Physical origin of the anisotropic transmission lies in the different localizations in the defect layer of the two operations.

  12. Network analysis of rat spatial cognition: behaviorally-established symmetry in a physically asymmetrical environment.

    Directory of Open Access Journals (Sweden)

    Shahaf Weiss

    Full Text Available BACKGROUND: We set out to solve two inherent problems in the study of animal spatial cognition (i What is a "place"?; and (ii whether behaviors that are not revealed as differing by one methodology could be revealed as different when analyzed using a different approach. METHODOLOGY: We applied network analysis to scrutinize spatial behavior of rats tested in either a symmetrical or asymmetrical layout of 4, 8, or 12 objects placed along the perimeter of a round arena. We considered locations as the units of the network (nodes, and passes between locations as the links within the network. PRINCIPAL FINDINGS: While there were only minor activity differences between rats tested in the symmetrical or asymmetrical object layouts, network analysis revealed substantial differences. Viewing 'location' as a cluster of stopping coordinates, the key locations (large clusters of stopping coordinates were at the objects in both layouts with 4 objects. However, in the asymmetrical layout with 4 objects, additional key locations were spaced by the rats between the objects, forming symmetry among the key locations. It was as if the rats had behaviorally imposed symmetry on the physically asymmetrical environment. Based on a previous finding that wayfinding is easier in symmetrical environments, we suggest that when the physical attributes of the environment were not symmetrical, the rats established a symmetric layout of key locations, thereby acquiring a more legible environment despite its complex physical structure. CONCLUSIONS AND SIGNIFICANCE: The present study adds a behavioral definition for "location", a term that so far has been mostly discussed according to its physical attributes or neurobiological correlates (e.g.--place and grid neurons. Moreover, network analysis enabled the assessment of the importance of a location, even when that location did not display any distinctive physical properties.

  13. Network analysis of rat spatial cognition: behaviorally-established symmetry in a physically asymmetrical environment.

    Science.gov (United States)

    Weiss, Shahaf; Yaski, Osnat; Eilam, David; Portugali, Juval; Blumenfeld-Lieberthal, Efrat

    2012-01-01

    We set out to solve two inherent problems in the study of animal spatial cognition (i) What is a "place"?; and (ii) whether behaviors that are not revealed as differing by one methodology could be revealed as different when analyzed using a different approach. We applied network analysis to scrutinize spatial behavior of rats tested in either a symmetrical or asymmetrical layout of 4, 8, or 12 objects placed along the perimeter of a round arena. We considered locations as the units of the network (nodes), and passes between locations as the links within the network. While there were only minor activity differences between rats tested in the symmetrical or asymmetrical object layouts, network analysis revealed substantial differences. Viewing 'location' as a cluster of stopping coordinates, the key locations (large clusters of stopping coordinates) were at the objects in both layouts with 4 objects. However, in the asymmetrical layout with 4 objects, additional key locations were spaced by the rats between the objects, forming symmetry among the key locations. It was as if the rats had behaviorally imposed symmetry on the physically asymmetrical environment. Based on a previous finding that wayfinding is easier in symmetrical environments, we suggest that when the physical attributes of the environment were not symmetrical, the rats established a symmetric layout of key locations, thereby acquiring a more legible environment despite its complex physical structure. The present study adds a behavioral definition for "location", a term that so far has been mostly discussed according to its physical attributes or neurobiological correlates (e.g.--place and grid neurons). Moreover, network analysis enabled the assessment of the importance of a location, even when that location did not display any distinctive physical properties.

  14. INFLUENCE OF NOSE PERTURBATIONS ON BEHAVIORS OF ASYMMETRIC VORTICES OVER SLENDER BODY

    Institute of Scientific and Technical Information of China (English)

    陈学锐; 邓学蓥; 王延奎; 刘沛清; 顾志福

    2002-01-01

    The influence of nose perturbations on the behaviors of asymmetricvortices over a slender body with a three-caliber ogive nose is studied in this paper.The tests of a nose-disturbed slender body with surface pressure measurement wereconducted at a low speed wind tunnel with subcritical Reynolds number of 1×105 atangle of attack α= 50°. The experiment results show that the behaviors and struc-ture of asymmetric vortices over the slender body are mainly controlled by manualperturbation on the nose of body as compared with geometrical minute irregularitieson the test model from the machining tolerances. The effect of the perturbation ax-ial location on asymmetric vortices is the strongest if its location is near the modelapex. There are four sensitive circumferential locations of manual perturbation atwhich bistable vortices over the slender body are switched by the perturbation. Theflowfleld near the reattachment line of lee side is more sensitive to the perturbation,because the saddle point to saddle point topological structure in this reattachmentflowfield is unstable. Various types of perturbation do not change the perturbationeffect on the behaviors of bistable asymmetric vortices.

  15. Asymmetric unwrapping of nucleosomes under tension directed by DNA local flexibility.

    Science.gov (United States)

    Ngo, Thuy T M; Zhang, Qiucen; Zhou, Ruobo; Yodh, Jaya G; Ha, Taekjip

    2015-03-12

    Dynamics of the nucleosome and exposure of nucleosomal DNA play key roles in many nuclear processes, but local dynamics of the nucleosome and its modulation by DNA sequence are poorly understood. Using single-molecule assays, we observed that the nucleosome can unwrap asymmetrically and directionally under force. The relative DNA flexibility of the inner quarters of nucleosomal DNA controls the unwrapping direction such that the nucleosome unwraps from the stiffer side. If the DNA flexibility is similar on two sides, it stochastically unwraps from either side. The two ends of the nucleosome are orchestrated such that the opening of one end helps to stabilize the other end, providing a mechanism to amplify even small differences in flexibility to a large asymmetry in nucleosome stability. Our discovery of DNA flexibility as a critical factor for nucleosome dynamics and mechanical stability suggests a novel mechanism of gene regulation by DNA sequence and modifications.

  16. Impacts of complex behavioral responses on asymmetric interacting spreading dynamics in multiplex networks

    CERN Document Server

    Liu, Quan-Hui; Tang, Ming; Zhang, Hai-Feng

    2015-01-01

    Information diffusion and disease spreading in communication-contact layered network are typically asymmetrically coupled with each other, in which how an individual being aware of disease responds to the disease can significantly affect the disease spreading. Many recent studies have demonstrated that human behavioral adoption is a complex and non-Markovian process, where the probability of adopting one behavior is dependent on the cumulative times of the received information and the social reinforcement effect of these cumulative information. We study the impact of such a non-Markovian vaccination adoption behavior on the epidemic dynamics and the control effects. We find that this complex adoption behavior caused from the communication layer can significantly increase the epidemic threshold and reduce the final infection rate. By defining the social cost as the sum of the cost of vaccination and the cost of treatment, we show that there exists an optimal social reinforcement effect or optimal information t...

  17. Directed orientation of asymmetric composite dumbbells by electric field induced assembly.

    Science.gov (United States)

    Nagao, Daisuke; Sugimoto, Maki; Okada, Ayako; Ishii, Haruyuki; Konno, Mikio; Imhof, Arnout; van Blaaderen, Alfons

    2012-04-24

    Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells, which were composed of a polymethylmethacrylate (PMMA)-coated sphere (core-shell part) and a polystyrene (PSt) lobe, were synthesized with a soap-free emulsion polymerization to prepare PMMA-coated inorganic spheres and another soap-free emulsion polymerization to form a polystyrene (PSt) lobe from the PMMA-coated inorganic spheres. The composite dumbbells dispersed in water were directly observed with optical microscopy. The dumbbells incorporating a silica sphere oriented parallel to an electric field in the whole frequency range and they formed a pearl chain structure at a high frequency of 2 MHz. The titania-incorporated dumbbells formed chain structures, in which they contacted their core-shell parts and oriented perpendicularly to a low-frequency (kHz) field, whereas they oriented parallel to a high-frequency (MHz) field. Since the alignment of dumbbells in the chains depends not only on the interparticle forces but also on the torque that the induced dipoles in the dumbbells experience in the electric field, the orientation of dumbbells perpendicular to the electric field was the case dominated by the interparticle force, whereas the other orientation was the case dominated by the torque. The present experiments show that the incorporation of inorganic dumbbells is an effective way to control the assembled structure and orientation with an electric field.

  18. Structural tailoring effects on the magnetic behavior of symmetric and asymmetric cubane-type Ni complexes.

    Science.gov (United States)

    Ponomaryov, Alexey N; Kim, Namseok; Hwang, Jaewon; Nojiri, Hiroyuki; van Tol, Johan; Ozarowski, Andrew; Park, Jena; Jang, Zeehoon; Suh, Byoungjin; Yoon, Sungho; Choi, Kwang-Yong

    2013-06-01

    Using two kinds of carboxylate ligands with small but significant differences in steric size, symmetric and asymmetric Fe(II) and Ni(II) cubanes have been synthesized in a controlled fashion. Fast sweeping pulsed field measurements showed magnetization hysteresis loops for two cubane-type molecular complexes, [Ni4(μ-OMe)4(O2CAr(4F-Ph))4(HOMe)8] and [Ni4(μ-OMe)4(O2CAr(Tol))4(HOMe)6], thus suggesting single-molecule magnet behavior. To differentiate the magnetic properties between the symmetric and asymmetric cubanes, detailed electron paramagnetic resonance (EPR) measurements were performed. From the EPR data, taken at various frequencies and temperatures, zero-field splitting parameters D, E, and other higher-order parameters for both cubane samples were extracted. Compared to the symmetric Ni-cubane, the asymmetric one shows an increase in the D and E values by about 20%, thereby suggesting structural engineering effects on the magnetic properties. By using the magnetic parameters determined by EPR, a static magnetization curve at 2 K and a temperature dependence of the magnetic susceptibility were simulated. A good agreement between theoretical and experimental data confirms the validity of the values obtained from EPR measurements.

  19. Infant behaviors influence mothers' provision of responsive and directive behaviors.

    Science.gov (United States)

    Lloyd, Carrie A; Masur, Elise Frank

    2014-08-01

    Mother-infant interactions are important to infant development because they are predictive of infants' social, cognitive, and language development (Lamb, Bornstein, & Teti, 2002; Tamis-LeMonda, Bornstein, & Baumwell, 2001). Because maternal responsive and directive behaviors are associated with differential infant outcomes, it is important to investigate influences on mothers' provision of responsive and directive behaviors. Yet, the dyadic interaction literature is predominantly unidirectional from maternal behavior to infant outcomes. Therefore, the current study examined infant initiating behaviors and consequent maternal responses in a sample of 26 13-month-old infants and their mothers, videotaped during 5 min of free-play. Findings revealed that infants produced a variety of initiatives, and that these different infant initiatives prompted differential patterns of maternal responsive versus directive behaviors. Further, results of analyses of divergent types of maternal directive behaviors - Responsive Directives, ReDirectives, and Intrusive Directives - also may help clarify major discrepancies in the current literature regarding the positive and negative effects of maternal directiveness.

  20. Critical behavior near the Mott transition in the half-filled asymmetric Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Anh-Tuan, E-mail: hatuan@iop.vast.ac.vn [Institute of Physics, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Le, Duc-Anh [Faculty of Physics, Hanoi National University of Education, Xuan Thuy 136, Cau Giay, Hanoi 10000 (Viet Nam)

    2016-03-15

    We study the half-filled asymmetric Hubbard model within the two-site dynamical mean field theory. At zero temperature, explicit expressions of the critical interaction U{sub c} for the Mott transition and the local self-energy are analytically derived. Critical behavior of the quasiparticle weights and the double occupancy are obtained analytically as functions of the on-site interaction U and the hopping asymmetry r. Our results are in good agreement with the ones obtained by much more sophisticated theory.

  1. Examining the Cultural Leadership Behaviors of Schoo l Principal s within the Context of Symmetric and Asymmetric School Culture

    Directory of Open Access Journals (Sweden)

    Betül BALKAR

    2015-08-01

    Full Text Available The aim of this study is to determine the opinions of teachers on contributions of school principals’ cultural leadership behaviors to forming symmetric and asymmetric culture. The participants of the study consisted of 27 secondary school teachers working in Gaziantep province. Data of the study were collected through semi - structured interviews and analyzed through content analysis. Contributions of each cultural leader ship behavior to symmetric and asymmetric culture types were determined by taking relations between cultural leadership behaviors and symmetric and asymmetric cultures into consideration in the process of content analysis. According to the findings of the study ; supporting development of teachers and reflecting developments and innovations on schools are among the cultural leadership behaviors contributing to forming asymmetric culture at schools. Interpreting tasks and missions of school and ensuring neces sary environment for keeping social values alive at schools are among the cultural leadership behaviors contributing to forming symmetric culture at schools. Based on the results of the study, it is suggested that school principals should follow developmen ts in educational issues and transfer these developments into school practices. They should place more importance on supporting innovative behaviors of teachers in order to create asymmetric culture at schools.

  2. The asymmetric Goos-H\\"anchen effect

    OpenAIRE

    Araujo, Manoel P.; Carvalho, Silvânia A.; De Leo, Stefano

    2013-01-01

    We show in which conditions optical gaussian beams, propagating throughout an homogeneous dielectric right angle prism, present an asymmetric Goos-H\\"anchen (GH) effect. This asymmetric behavior is seen for incidence at critical angles and happens in the propagation direction of the outgoing beam. The asymmetric GH effect can be also seen as an amplification of the standard GH shift. Due to the fact that it only depends on the ratio between the wavelength and the minimal waist size of the inc...

  3. Dynamical behaviors of an exciton in an asymmetric double coupled quantum dot

    Institute of Scientific and Technical Information of China (English)

    LIU Can-de; LIU Wen; LI Feng-ling; WU Da-peng; SU Xi-yu

    2006-01-01

    Dynamical behaviors of an exciton in an asymmetric double coupled quantum dot and an altematingcurrent (ac) electric field have been analyzed based on the two-level approximation theory,and the conditions under which dynamical localization occurs are obtained.It shows that when the amplitude of the ac electric field is small,the Coulomb interaction plays an important role.The dynamical behaviors of the exciton are mainly confined in the low-level subspace.When the ratio of the field intensity to frequency is the root of Bessel function,electron and hole are localized in one dot,and they can be divided with the increasing amplitude of the ac electric field.

  4. Localized domain wall nucleation dynamics in asymmetric ferromagnetic rings revealed by direct time-resolved magnetic imaging

    Science.gov (United States)

    Richter, Kornel; Krone, Andrea; Mawass, Mohamad-Assaad; Krüger, Benjamin; Weigand, Markus; Stoll, Hermann; Schütz, Gisela; Kläui, Mathias

    2016-07-01

    We report time-resolved observations of field-induced domain wall nucleation in asymmetric ferromagnetic rings using single direction field pulses and rotating fields. We show that the asymmetric geometry of a ring allows for controlling the position of nucleation events, when a domain wall is nucleated by a rotating magnetic field. Direct observation by scanning transmission x-ray microscopy (STXM) reveals that the nucleation of domain walls occurs through the creation of transient ripplelike structures. This magnetization state is found to exhibit a surprisingly high reproducibility even at room temperature and we determine the combinations of field strengths and field directions that allow for reliable nucleation of domain walls and directly quantify the stability of the magnetic states. Our analysis of the processes occurring during field induced domain wall nucleation shows how the effective fields determine the nucleation location reproducibly, which is a key prerequisite toward using domain walls for spintronic devices.

  5. Electrochromic Asymmetric Supercapacitor Windows Enable Direct Determination of Energy Status by the Naked Eye.

    Science.gov (United States)

    Zhong, Ying; Chai, Zhisheng; Liang, Zhimin; Sun, Peng; Xie, Weiguang; Zhao, Chuanxi; Mai, Wenjie

    2017-09-19

    Because of the popularity of smart electronics, multifunctional energy storage devices, especially electrochromic supercapacitors (SCs), have attracted tremendous research interest. Herein, a solid-state electrochromic asymmetric SC (ASC) window is designed and fabricated by introducing WO3 and polyaniline as the negative and positive electrodes, respectively. The two complementary materials contribute to the outstanding electrochemical and electrochromic performances of the fabricated device. With an operating voltage window of 1.4 V and an areal capacitance of 28.3 mF cm(-2), the electrochromic devices show a high energy density of 7.7 × 10(-3) mW h cm(-2). Meanwhile, they exhibit an obvious and reversible color transition between light green (uncharged state) and dark blue (charged state), with an optical transmittance change between 55 and 12% at a wavelength of 633 nm. Hence, the energy storage level of the ASC is directly related to its color and can be determined by the naked eye, which means it can be incorporated with other energy cells to visual display their energy status. Particularly, a self-powered and color-indicated system is achieved by combining the smart windows with commercial solar cell panels. We believe that the novel electrochromic ASC windows will have great potential application for both smart electronics and smart buildings.

  6. Direction- and Salt-Dependent Ionic Current Signatures for DNA Sensing with Asymmetric Nanopores.

    Science.gov (United States)

    Chen, Kaikai; Bell, Nicholas A W; Kong, Jinglin; Tian, Yu; Keyser, Ulrich F

    2017-02-28

    Solid-state nanopores are promising tools for single-molecule detection of both DNA and proteins. In this study, we investigated the patterns of ionic current blockades as DNA translocates into or out of the geometric confinement of conically shaped pores across a wide range of salt conditions. We studied how the geometry of a nanopore affects the detected ionic current signal of a translocating DNA molecule over a wide range of salt concentration. The blockade level in the ionic current depends on the translocation direction at a high salt concentration, and at lower salt concentrations we find a nonintuitive ionic current decrease and increase within each single event for the DNA translocations exiting from confinement. We use a recently developed method for synthesizing DNA molecules with multiple position markers, which provides further experimental characterization by matching the position of the DNA in the pore with the observed ionic current signal. Finally, we employ finite element calculations to explain the shapes of the signals observed at all salt concentrations and show that the unexpected current decrease and increase are due to the competing effects of ion concentration polarization and geometric exclusion of ions. Our analysis shows that over a wide range of geometries, voltages, and salt concentrations, we are able to understand the ionic current signals of DNA in asymmetric nanopores, enabling signal optimization in molecular sensing applications.

  7. Directed flow in asymmetric nucleus-nucleus collisions and the inverse Landau-Pomeranchuk-Migdal effect

    CERN Document Server

    Toneev, V D; Kolomeitsev, E E; Cassing, W

    2016-01-01

    It is proposed to identify a strong electric field - created during relativistic collisions of asymmetric nuclei - via the observation of pseudorapidity and transverse momentum distributions of hadrons with the same mass but opposite charge. The results of detailed calculations within the Parton-Hadron String Dynamics (PHSD) approach for the charge-dependent directed flow $v_1$ are presented for semi-central Cu+Au collision at $\\sqrt{s_{NN}}=200$ GeV incorporating the inverse Landau-Pomeranchuk-Migdal (iLPM) effect, which accounts for a delay in the electromagnetic interaction with the charged degree of freedom. Including the iLPM effect we achieve a reasonable agreement of the PHSD results for the charge splitting in $v_1(p_T)$ in line with the recent measurements of the STAR Collaboration for Cu+Au collisions at $\\sqrt{s_{NN}}=200$ GeV while an instant appearance and coupling of electric charges at the hard collision vertex overestimates the splitting by about a factor of 10. We predict that the iLPM effect...

  8. Influence of Uncertainties on the Dynamic Buckling Loads of Structures Liable to Asymmetric Postbuckling Behavior

    Directory of Open Access Journals (Sweden)

    Paulo B. Gonçalves

    2008-01-01

    Full Text Available Structural systems liable to asymmetric bifurcation usually become unstable at static load levels lower than the linear buckling load of the perfect structure. This is mainly due to the imperfections present in real structures. The imperfection sensitivity of structures under static loading is well studied in literature, but little is know on the sensitivity of these structures under dynamic loads. The aim of the present work is to study the behavior of an archetypal model of a harmonically forced structure, which exhibits, under increasing static load, asymmetric bifurcation. First, the integrity of the system under static load is investigated in terms of the evolution of the safe basin of attraction. Then, the stability boundaries of the harmonically excited structure are obtained, considering different loading processes. The bifurcations connected with these boundaries are identified and their influence on the evolution of safe basins is investigated. Then, a parametric analysis is conducted to investigate the influence of uncertainties in system parameters and random perturbations of the forcing on the dynamic buckling load. Finally, a safe lower bound for the buckling load, obtained by the application of the Melnikov criterion, is proposed which compare well with the scatter of buckling loads obtained numerically.

  9. Impacts of complex behavioral responses on asymmetric interacting spreading dynamics in multiplex networks

    Science.gov (United States)

    Liu, Quan-Hui; Wang, Wei; Tang, Ming; Zhang, Hai-Feng

    2016-05-01

    Information diffusion and disease spreading in communication-contact layered network are typically asymmetrically coupled with each other, in which disease spreading can be significantly affected by the way an individual being aware of disease responds to the disease. Many recent studies have demonstrated that human behavioral adoption is a complex and non-Markovian process, where the probability of behavior adoption is dependent on the cumulative times of information received and the social reinforcement effect of the cumulative information. In this paper, the impacts of such a non-Markovian vaccination adoption behavior on the epidemic dynamics and the control effects are explored. It is found that this complex adoption behavior in the communication layer can significantly enhance the epidemic threshold and reduce the final infection rate. By defining the social cost as the total cost of vaccination and treatment, it can be seen that there exists an optimal social reinforcement effect and optimal information transmission rate allowing the minimal social cost. Moreover, a mean-field theory is developed to verify the correctness of simulation results.

  10. Asymmetric voltage behavior of the tunnel magnetoresistance in double barrier magnetic tunnel junctions

    KAUST Repository

    Useinov, Arthur

    2012-06-01

    In this paper, we study the value of the tunnel magnetoresistance (TMR) as a function of the applied voltage in double barrier magnetic tunnel junctions (DMTJs) with the left and right ferromagnetic (FM) layers being pinned and numerically estimate the possible difference of the TMR curves for negative and positive voltages in the homojunctions (equal barriers and electrodes). DMTJs are modeled as two single barrier junctions connected in series with consecutive tunneling (CST). We investigated the asymmetric voltage behavior of the TMR for the CST in the range of a general theoretical model. Significant asymmetries of the experimental curves, which arise due to different annealing regimes, are mostly explained by different heights of the tunnel barriers and asymmetries of spin polarizations in magnetic layers. © (2012) Trans Tech Publications.

  11. Output voltage calculations in double barrier magnetic tunnel junctions with asymmetric voltage behavior

    KAUST Repository

    Useinov, Arthur

    2011-10-22

    In this paper we study the asymmetric voltage behavior (AVB) of the tunnel magnetoresistance (TMR) for single and double barrier magnetic tunnel junctions (MTJs) in range of a quasi-classical free electron model. Numerical calculations of the TMR-V curves, output voltages and I-V characteristics for negative and positive values of applied voltages were carried out using MTJs with CoFeB/MgO interfaces as an example. Asymmetry of the experimental TMR-V curves is explained by different values of the minority and majority Fermi wave vectors for the left and right sides of the tunnel barrier, which arises due to different annealing regimes. Electron tunneling in DMTJs was simulated in two ways: (i) Coherent tunneling, where the DMTJ is modeled as one tunnel system and (ii) consecutive tunneling, where the DMTJ is modeled by two single barrier junctions connected in series. © 2012 Elsevier B.V. All rights reserved.

  12. The asymmetric Goos-H\\"anchen effect

    CERN Document Server

    Araujo, Manoel P; De Leo, Stefano

    2014-01-01

    We show in which conditions optical gaussian beams, propagating throughout an homogeneous dielectric right angle prism, present an asymmetric Goos-H\\"anchen (GH) effect. This asymmetric behavior is seen for incidence at critical angles and happens in the propagation direction of the outgoing beam. The asymmetric GH effect can be also seen as an amplification of the standard GH shift. Due to the fact that it only depends on the ratio between the wavelength and the minimal waist size of the incoming gaussian beam, it can be also used to determine one of these parameters. Multiple peaks interference is an additional phenomenon seen in the presence of such asymmetric effects.

  13. Unravelling Thiol’s Role in Directing Asymmetric Growth of Au Nanorod–Au Nanoparticle Dimers

    KAUST Repository

    Huang, Jianfeng

    2015-12-15

    Asymmetric nanocrystals have practical significance in nanotechnologies but present fundamental synthetic challenges. Thiol ligands have proven effective in breaking the symmetric growth of metallic nanocrystals but their exact roles in the synthesis remain elusive. Here, we synthesized an unprecedented Au nanorod-Au nanoparticle (AuNR-AuNP) dimer structure with the assistance of a thiol ligand. On the basis of our experimental observations, we unraveled for the first time that the thiol could cause an inhomogeneous distribution of surface strains on the seed crystals as well as a modulated reduction rate of metal precursors, which jointly induced the asymmetric growth of monometallic dimers. © 2015 American Chemical Society.

  14. Chitosan aerogel: a recyclable, heterogeneous organocatalyst for the asymmetric direct aldol reaction in water.

    Science.gov (United States)

    Ricci, Alfredo; Bernardi, Luca; Gioia, Claudio; Vierucci, Simone; Robitzer, Mike; Quignard, Françoise

    2010-09-14

    Aerogel microspheres of chitosan, an abundant biopolymer obtained from marine crustaceans, have been successfully applied to catalyze the asymmetric aldol reaction in water, providing the products in high yields and with good stereoselectivity (up to 93% ee) and recyclability (up to 4 runs). Yields were favourably affected by additives such as DNP and stearic acid.

  15. Laser directed lithography of asymmetric graphene ribbons on a polydimethylsiloxane trench structure.

    Science.gov (United States)

    Tian, He; Yang, Yi; Xie, Dan; Ren, Tian-Ling; Shu, Yi; Sun, Hui; Zhou, Chang-Jian; Liu, Xuan; Tao, Lu-Qi; Ge, Jie; Zhang, Cang-Hai; Zhang, Yuegang

    2013-05-14

    Recently, manipulating heat transport by asymmetric graphene ribbons has received significant attention, in which phonons in the carbon lattice are used to carry energy. In addition to heat control, asymmetric graphene ribbons might also have broad applications in renewable energy engineering, such as thermoelectric energy harvesting. Here, we transfer a single sheet of graphene over a 5 μm trench of polydimethylsiloxane (PDMS) structure. By using a laser (1.77 mW, 1 μm diameter spot size, 517 nm wavelength) focusing on one side of the suspended graphene, a triangular shaped graphene ribbon is obtained. As the graphene has a negative thermal expansion coefficient, local laser heating could make the affected graphene area shrink and eventually break. Theoretical calculation shows that the 1.77 mW laser could create a local hot spot as high as 1462.5 °C, which could induce an asymmetric shape structure. We also find the temperature coefficient (-13.06 cm(-1) mW) of suspended graphene on PDMS trench substrate is ten times higher than that reported on SiO2/Si trench substrate. Collectively, our results raise the exciting prospect that the realization of graphene with asymmetric shape on thermally insulating substrate is technologically feasible, which may open up important applications in thermal circuits and thermal management.

  16. Radio electric asymmetric brain stimulation in the treatment of behavioral and psychiatric symptoms in Alzheimer disease

    Directory of Open Access Journals (Sweden)

    Mannu P

    2011-07-01

    Full Text Available Piero Mannu1, Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna11Rinaldi Fontani Institute, Department of Neuro Psycho Physio Pathology, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, ItalyPurpose: Behavioral and psychiatric symptoms of dementia (BPSD are common in Alzheimer's disease (AD and disrupt the effective management of AD patients. The present study explores the use of radio electric asymmetric brain stimulation (REAC in patients who have had a poor response to pharmacological treatment.Patients and methods: Eight patients (five females and three males; mean [±standard deviation] age at study baseline: 69.9 ± 3.0 years diagnosed with AD according to the DSM-IV-TR criteria (mean onset age of AD: 65.4 ± 3.5 years were cognitively and psychometrically assessed with the Mini-Mental State Examination (MMSE, the Activity of Daily Living (ADL, the Instrumental Activity of Daily Living (IADL, and the Neuropsychiatric Inventory (NPI, prior to and after each of 2 REAC treatment cycles.Results: Scores on the MMSE and all subscales of the NPI (frequency, severity, and distress, the ADL, and the IADL were significantly improved following the initial REAC treatment. There was further significant improvement in all measurements (with a tendency for improvement in the IADL after the second REAC treatment cycle.Conclusion: The improvement of cognitive and behavioral/psychiatric functioning following REAC treatment suggests that this innovative approach may be an effective, safe, and tolerable alternative to pharmacological treatment of AD patients, especially in the area of BPSD. Elderly patients suffering from other types of dementia may also benefit from REAC treatment.Keywords: anxiety, depression, insomnia, behavioral and psychiatric symptoms of dementia (BPSD

  17. Behavioral profiles displayed by rats in an elevated asymmetric plus-maze: effects of diazepam

    Directory of Open Access Journals (Sweden)

    Ruarte M.B.

    1999-01-01

    Full Text Available When rats are exposed to unknown environments where novelty and fear-inducing characteristics are present (conflictive environments, some specific behaviors are induced and exploration is apparently modulated by fear. In our laboratory, a new type of plus-maze was designed as a model of conflictive exploration. The maze is composed of four arms with different geometrical characteristics, differing from each other by the presence or absence of walls. The degree of asymmetry was as follows: NW, no wall arm; SW, a single high wall present; HL, a low and a high wall present, and HH, two high walls present. The four arms were arranged at 90o angles and the apparatus was called the elevated asymmetric plus-maze (APM. The purpose of the present study was to assess the behavioral profile of rats exposed for a single time to the APM with or without treatment with benzodiazepine. Increasing doses of diazepam were injected intraperitoneally in several groups of male, 90-day-old Holtzman rats. Distilled water was injected in control animals. Thirty minutes after treatment all rats were exposed singly to a 5-min test in the APM. Diazepam induced a biphasic modification of exploration in the NW and SW arms. The increase in the exploration score was evident at low doses of diazepam (0.25-1.0 mg/kg body weight and the decrease in exploration was found with the higher doses of diazepam (2.0-3.0 mg/kg body weight. Non-exploratory behaviors (permanency were not affected by benzodiazepine treatment. In the HL arm, exploration was not modified but permanency was increased in a dose-dependent manner. In the HH arm, exploration and permanency were not affected. Results are compatible with the idea that exploration-processing mechanisms in conflictive environments are modulated by fear-processing mechanisms of the brain.

  18. Driver Behavior Modeling: Developments and Future Directions

    Directory of Open Access Journals (Sweden)

    Najah AbuAli

    2016-01-01

    Full Text Available The advances in wireless communication schemes, mobile cloud and fog computing, and context-aware services boost a growing interest in the design, development, and deployment of driver behavior models for emerging applications. Despite the progressive advancements in various aspects of driver behavior modeling (DBM, only limited work can be found that reviews the growing body of literature, which only targets a subset of DBM processes. Thus a more general review of the diverse aspects of DBM, with an emphasis on the most recent developments, is needed. In this paper, we provide an overview of advances of in-vehicle and smartphone sensing capabilities and communication and recent applications and services of DBM and emphasize research challenges and key future directions.

  19. Egf Signaling Directs Neoblast Repopulation by Regulating Asymmetric Cell Division in Planarians.

    Science.gov (United States)

    Lei, Kai; Thi-Kim Vu, Hanh; Mohan, Ryan D; McKinney, Sean A; Seidel, Chris W; Alexander, Richard; Gotting, Kirsten; Workman, Jerry L; Sánchez Alvarado, Alejandro

    2016-08-22

    A large population of proliferative stem cells (neoblasts) is required for physiological tissue homeostasis and post-injury regeneration in planarians. Recent studies indicate that survival of a few neoblasts after sublethal irradiation results in the clonal expansion of the surviving stem cells and the eventual restoration of tissue homeostasis and regenerative capacity. However, the precise mechanisms regulating the population dynamics of neoblasts remain largely unknown. Here, we uncovered a central role for epidermal growth factor (EGF) signaling during in vivo neoblast expansion mediated by Smed-egfr-3 (egfr-3) and its putative ligand Smed-neuregulin-7 (nrg-7). Furthermore, the EGF receptor-3 protein localizes asymmetrically on the cytoplasmic membrane of neoblasts, and the ratio of asymmetric to symmetric cell divisions decreases significantly in egfr-3(RNAi) worms. Our results not only provide the first molecular evidence of asymmetric stem cell divisions in planarians, but also demonstrate that EGF signaling likely functions as an essential regulator of neoblast clonal expansion.

  20. Projection of two-dimensional diffusion in narrow asymmetric channels onto the longitudinal direction

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, Inti; Dagdug, Leonardo [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, 09340 México Distrito Federal (Mexico)

    2014-01-14

    Diffusive transport of particles is a ubiquitous feature of physical, chemical and biological systems. Typical structures like pores, tubes or fibers, are quasi one-dimensional, such that we need to solve 2+1 or 3+1 dimensional differential equations to describe correctly transport along them. The so-called Fick-Jacobs approach dramatically simplifies the problem if one assumes that a solute distribution in any cross-section of the channel is uniform at equilibrium. That study focuses on the mapping of the diffusion equation in a two-dimensional narrow asymmetric channel of varying cross section onto the longitudinal coordinate. We present a generalization to the case of an asymmetric channel using the projection method introduced earlier by Kalinay and Percus. We derive an expansion of the effective diffusion coefficient, which represents corrections to the Fick-Jacobs equation and contains the well-known previous results as special cases. Finally, we study numerically some specific two-dimensional asymmetric channel configurations to test and show the broader applicability of this effective diffusion coefficient formula.

  1. The Par complex and integrins direct asymmetric cell division in adult intestinal stem cells.

    Science.gov (United States)

    Goulas, Spyros; Conder, Ryan; Knoblich, Juergen A

    2012-10-05

    The adult Drosophila midgut is maintained by intestinal stem cells (ISCs) that generate both self-renewing and differentiating daughter cells. How this asymmetry is generated is currently unclear. Here, we demonstrate that asymmetric ISC division is established by a unique combination of extracellular and intracellular polarity mechanisms. We show that Integrin-dependent adhesion to the basement membrane induces cell-intrinsic polarity and results in the asymmetric segregation of the Par proteins Par-3, Par-6, and aPKC into the apical daughter cell. Cell-specific knockdown and overexpression experiments suggest that increased activity of aPKC enhances Delta/Notch signaling in one of the two daughter cells to induce terminal differentiation. Perturbing this mechanism or altering the orientation of ISC division results in the formation of intestinal tumors. Our data indicate that mechanisms for intrinsically asymmetric cell division can be adapted to allow for the flexibility in lineage decisions that is required in adult stem cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Asymmetrical behavioral response towards two boron toxicants depends on the ant species (Hymenoptera: Formicidae).

    Science.gov (United States)

    Sola, Francisco; Falibene, Agustina; Josens, Roxana

    2013-04-01

    Urban ants are a worldwide critical household pests, and efforts to control them usually involve the use of alimentary baits containing slow-acting insecticides. A common toxicant used is boron, either as borax or boric acid. However, the presence of these compounds can affect the consumption of baits by reducing their acceptance and ingestion. Moreover, as feeding motivation varies widely, according not only to food properties but also to colony conditions, bait consumption might be diminished further in certain situations. In this study, we compared the feeding response of ants toward two boron toxic baits (boric acid and borax) in low motivation situations that enhance any possible phago-deterrence the baits may produce. Most studies investigating bait ingestion evaluate whole nests or groups of ants; here, we analyzed the individual ingestion behavior and mortality of the Argentine ant, Linepithema humile (Mayr), and the carpenter ant, Camponotus mus (Roger), for two boron baits, to detect which compound generates a higher rejection in each of these species. Although these two species have similar feeding habits, our results showed that ants under low motivation conditions reduced the acceptance and consumption of the toxic baits asymmetrically. While L. humile mostly rejected the borax, C. mus rejected the boric acid. These results denote the importance of considering the preference of each species when developing a pest management strategy.

  3. A new asymmetric directional microphone algorithm with automatic mode-switching ability for binaural hearing support devices.

    Science.gov (United States)

    Kim, Jinryoul; Nam, Kyoung Won; Yook, Sunhyun; Jang, Dong Pyo; Kim, In Young; Hong, Sung Hwa

    2015-06-01

    For hearing support devices, it is important to minimize the negative effect of ambient noises for speech recognition but also, at the same time, supply natural ambient sounds to the hearing-impaired person. However, conventional fixed bilateral asymmetric directional microphone (DM) algorithms cannot perform in such a way when the DM-mode device and a dominant noise (DN) source are placed on the same lateral hemisphere. In this study, a new binaural asymmetric DM algorithm that can overcome the defects of conventional algorithms is proposed. The proposed algorithm can estimate the position of a specific DN in the 90°-270° range and switch directional- and omnidirectional-mode devices automatically if the DM-mode device and the DN are placed in opposite lateral hemispheres. Computer simulation and KEMAR mannequin recording tests demonstrated that the performance of the conventional algorithm deteriorated when the DM-mode device and the DN were placed in the opposite hemisphere; in contrast, the performance of the proposed algorithm was consistently maintained regardless of directional variations in the DN. Based on these experimental results, the proposed algorithm may be able to improve speech quality and intelligibility for hearing-impaired persons who have similar degrees of hearing impairment in both ears.

  4. Direct asymmetric allylic alkenylation of N-itaconimides with Morita-Baylis-Hillman carbonates

    KAUST Repository

    Yang, Wenguo

    2012-08-03

    The asymmetric allylic alkenylation of Morita-Baylis-Hillman (MBH) carbonates with N-itaconimides as nucleophiles has been developed using a commercially available Cinchona alkaloid catalyst. A variety of multifunctional chiral α-methylene-β-maleimide esters were attained in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 91% ee). The origin of the regio- and stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed regio- and enantioselectivity. © 2012 American Chemical Society.

  5. A robust macroscopic model for normal-shear coupling, asymmetric and anisotropic behaviors of polycrystalline SMAs

    Science.gov (United States)

    Bodaghi, M.; Damanpack, A. R.; Liao, W. H.

    2016-07-01

    The aim of this article is to develop a robust macroscopic bi-axial model to capture self-accommodation, martensitic transformation/orientation/reorientation, normal-shear deformation coupling and asymmetric/anisotropic strain generation in polycrystalline shape memory alloys. By considering the volume fraction of martensite and its preferred direction as scalar and directional internal variables, constitutive relations are derived to describe basic mechanisms of accommodation, transformation and orientation/reorientation of martensite variants. A new definition is introduced for maximum recoverable strain, which allows the model to capture the effects of tension-compression asymmetry and transformation anisotropy. Furthermore, the coupling effects between normal and shear deformation modes are considered by merging inelastic strain components together. By introducing a calibration approach, material and kinetic parameters of the model are recast in terms of common quantities that characterize a uniaxial phase kinetic diagram. The solution algorithm of the model is presented based on an elastic-predictor inelastic-corrector return mapping process. In order to explore and demonstrate capabilities of the proposed model, theoretical predictions are first compared with existing experimental results on uniaxial tension, compression, torsion and combined tension-torsion tests. Afterwards, experimental results of uniaxial tension, compression, pure bending and buckling tests on {{NiTi}} rods and tubes are replicated by implementing a finite element method along with the Newton-Raphson and Riks techniques to trace non-linear equilibrium path. A good qualitative and quantitative correlation is observed between numerical and experimental results, which verifies the accuracy of the model and the solution procedure.

  6. Direct observation of exceptional points in coupled photonic-crystal lasers with asymmetric optical gains

    Science.gov (United States)

    Kim, Kyoung-Ho; Hwang, Min-Soo; Kim, Ha-Reem; Choi, Jae-Hyuck; No, You-Shin; Park, Hong-Gyu

    2016-12-01

    Although counter-intuitive features have been observed in non-Hermitian optical systems based on micrometre-sized cavities, the achievement of a simplified but unambiguous approach to enable the efficient access of exceptional points (EPs) and the phase transition to desired lasing modes remains a challenge, particularly in wavelength-scale coupled cavities. Here, we demonstrate coupled photonic-crystal (PhC) nanolasers with asymmetric optical gains, and observe the phase transition of lasing modes at EPs through tuning of the area of graphene cover on one PhC cavity and systematic scanning photoluminescence measurements. As the gain contrast between the two identical PhC cavities exceeds the intercavity coupling, the phase transition occurs from the bonding/anti-bonding lasing modes to the single-amplifying lasing mode, which is confirmed by the experimental measurement of the mode images and the theoretical modelling of coupled cavities with asymmetric gains. In addition, we demonstrate active tuning of EPs by controlling the optical loss of graphene through electrical gating.

  7. Femtosecond laser inscription of asymmetric directional couplers for in-fiber optical taps and fiber cladding photonics.

    Science.gov (United States)

    Grenier, Jason R; Fernandes, Luís A; Herman, Peter R

    2015-06-29

    Precise alignment of femtosecond laser tracks in standard single mode optical fiber is shown to enable controllable optical tapping of the fiber core waveguide light with fiber cladding photonic circuits. Asymmetric directional couplers are presented with tunable coupling ratios up to 62% and bandwidths up to 300 nm at telecommunication wavelengths. Real-time fiber monitoring during laser writing permitted a means of controlling the coupler length to compensate for micron-scale alignment errors and to facilitate tailored design of coupling ratio, spectral bandwidth and polarization properties. Laser induced waveguide birefringence was harnessed for polarization dependent coupling that led to the formation of in-fiber polarization-selective taps with 32 dB extinction ratio. This technology enables the interconnection of light propagating in pre-existing waveguides with laser-formed devices, thereby opening a new practical direction for the three-dimensional integration of optical devices in the cladding of optical fibers and planar lightwave circuits.

  8. A study of direct solar radiation transmission in asymmetrical multi-span greenhouses using scale models and simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, T.; Morales, M.I.; Castilla, N. [CIFA, Granada (Spain); Montero, J.I.; Anton, A. [IRTA, Barcelona (Spain); Sanchez-Guerrero, M.C.; Medrano, E. [CIFA, Almeria (Spain); Hernandez, J. [University of Almeria (Spain)

    2004-06-01

    Direct solar radiation transmission inside scale models of greenhouses with different roof slopes was measured and the results compared with calculations from a simulation model. Seven different roof slopes were tested, which had symmetrical and asymmetrical roof shapes: 8{sup o}-18{sup o}; 18{sup o}-8{sup o}; 27{sup o}-27{sup o}; 27{sup o}-45{sup o}; 36{sup o}-55{sup o}; 45{sup o}-27{sup o}; 55{sup o}-36{sup o} (8{sup o}-18{sup o} denoting that the south-facing slope was 8' and the north-facing one was 18{sup o}). Radiation transmission in scale models was quantified using linear solarimeters that integrated solar radiation along the cross-section of the span. The correlation between measured and calculated hourly and daily mean transmission values was good. Minor differences were attributed to the accumulation of dust and condensation on the scale models, two conditions that were not taken into account in the simulation model. The results of the study showed that direct solar radiation transmission increased considerably as slope increased, up to a value close to 30{sup o}, especially in the winter months in which radiation was most limited. Asymmetrical greenhouses did not always transmit more than symmetrical ones with similar slopes. In the cases studied, the scale model with 27{sup o}-27{sup o} symmetrical roof had the highest winter transmission. The use of scale models allowed different greenhouse structures to be characterised with respect to direct radiation transmission. This method can produce considerable savings of time and money and provides a realistic simulation of radiation transmission in full-scale greenhouses. (author)

  9. Direct imaging of an asymmetric debris disk in the HD 106906 planetary system

    CERN Document Server

    Kalas, Paul G; Wang, Jason J; Millar-Blanchaer, Maxwell A; Duchene, Gaspard; Chen, Christine; Fitzgerald, Michael P; Dong, Ruobing; Graham, James R; Patience, Jennifer; Macintosh, Bruce; Murray-Clay, Ruth; Matthews, Brenda; Rameau, Julien; Marois, Christian; Chilcote, Jeffrey; De Rosa, Robert J; Doyon, René; Draper, Zachary H; Lawler, Samantha; Ammons, S Mark; Arriaga, Pauline; Bulger, Joanna; Cotten, Tara; Follette, Katherine B; Goodsell, Stephen; Greenbaum, Alexandra; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Konapacky, Quinn; Lafreniere, David; Larkin, James E; Long, Douglas; Maire, Jérôme; Marchis, Franck; Metchev, Stan; Morzinski, Katie M; Nielsen, Eric L; Oppenheimer, Rebecca; Perrin, Marshall D; Pueyo, Laurent; Rantakyrö, Fredrik T; Ruffio, Jean-Baptiste; Saddlemyer, Leslie; Savransky, Dmitry; Schneider, Adam C; Sivaramakrishnan, Anand; Soummer, Rémi; Song, Inseok; Thomas, Sandrine; Vasisht, Gautam; Ward-Duong, Kimberly; Wiktorowicz, Sloane J; Wolff, Schuyler G

    2015-01-01

    We present the first scattered light detections of the HD 106906 debris disk using Gemini/GPI in the infrared and HST/ACS in the optical. HD 106906 is a 13 Myr old F5V star in the Sco-Cen association, with a previously detected planet-mass candidate HD 106906b projected 650 AU from the host star. Our observations reveal a near edge-on debris disk that has a central cleared region with radius $\\sim$50 AU, and an outer extent $>$500 AU. The HST data show the outer regions are highly asymmetric, resembling the ''needle'' morphology seen for the HD 15115 debris disk. The planet candidate is oriented $\\sim$21$\\deg$ away from the position angle of the primary's debris disk, strongly suggesting non-coplanarity with the system. We hypothesize that HD 106906b could be dynamically involved in the perturbation of the primary's disk, and investigate whether or not there is evidence for a circumplanetary dust disk or cloud that is either primordial or captured from the primary. We show that both the existing optical prope...

  10. DIRECT IMAGING OF AN ASYMMETRIC DEBRIS DISK IN THE HD 106906 PLANETARY SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Kalas, Paul G.; Wang, Jason J.; Duchene, Gaspard; Dong, Ruobing; Graham, James R.; Rosa, Robert J. De [Astronomy Department, University of California, Berkeley CA 94720-3411 (United States); Rajan, Abhijith; Patience, Jennifer [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Millar-Blanchaer, Maxwell A.; Chilcote, Jeffrey [Department of Astronomy and Astrophysics, University of Toronto, Toronto ON M5S 3H4 (Canada); Chen, Christine [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Fitzgerald, Michael P. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Macintosh, Bruce [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Murray-Clay, Ruth [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Matthews, Brenda; Marois, Christian; Draper, Zachary H.; Lawler, Samantha [National Research Council of Canada Herzberg, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Rameau, Julien; Doyon, René [Institut de Recherche sur les Exoplanetes, Département de Physique, Université de Montréal, Montréal QC H3C 3J7 (Canada); and others

    2015-11-20

    We present the first scattered light detections of the HD 106906 debris disk using the Gemini/Gemini Planet Imager in the infrared and Hubble Space Telescope (HST)/Advanced Camera for Surveys in the optical. HD 106906 is a 13 Myr old F5V star in the Sco–Cen association, with a previously detected planet-mass candidate HD 106906b projected 650 AU from the host star. Our observations reveal a near edge-on debris disk that has a central cleared region with radius ∼50 AU, and an outer extent >500 AU. The HST data show that the outer regions are highly asymmetric, resembling the “needle” morphology seen for the HD 15115 debris disk. The planet candidate is oriented ∼21° away from the position angle of the primary’s debris disk, strongly suggesting non-coplanarity with the system. We hypothesize that HD 106906b could be dynamically involved in the perturbation of the primary’s disk, and investigate whether or not there is evidence for a circumplanetary dust disk or cloud that is either primordial or captured from the primary. We show that both the existing optical properties and near-infrared colors of HD 106906b are weakly consistent with this possibility, motivating future work to test for the observational signatures of dust surrounding the planet.

  11. Direction selectivity in the larval zebrafish tectum is mediated by asymmetric inhibition

    Directory of Open Access Journals (Sweden)

    Abhinav eGrama

    2012-09-01

    Full Text Available The extraction of the direction of motion is an important computation performed by many sensory systems and in particular, the mechanism by which direction selective ganglion cells (DS-RGCs in the retina acquire their selective properties, has been studied extensively. However, whether DS-RGCs simply relay this information to downstream areas or whether additional and potentially de-novo processing occurs in these recipient structures is a matter of great interest. Neurons in the larval zebrafish tectum, the largest retino-recipent area in this animal, show direction selective responses to moving visual stimuli but how these properties are acquired is still unknown. In order to study this, we first used two-photon calcium imaging to classify the population responses of tectal cells to bars moving at different speeds and in different directions. Subsequently, we performed in-vivo whole cell electrophysiology on these direction selective tectal neurons and we found that their inhibitory inputs were strongly biased towards the null direction of motion, whereas the excitatory inputs showed little selectivity. In addition, we found that excitatory currents evoked by a stimulus moving in the preferred direction occurred before the inhibitory currents whereas a stimulus moving in the null direction evoked currents in the reverse temporal order. The membrane potential modulations resulting from these currents were enhanced by the spike generation mechanism to generate amplified direction selectivity in the spike output. Thus our results implicate a local inhibitory circuit in generating direction selectivity in tectal neurons.

  12. Phase behavior and critical properties of size-asymmetric, primitive-model electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuan; Prausnitz, John M.

    2004-04-01

    The theory of J. Jiang et al. [J. Chem. Phys. 116, 7977 (2002)] for size-symmetric electrolytes is extended to size-asymmetric electrolytes. When compared to molecular-simulation results, this extension gives the correct trend of critical properties with size asymmetry.

  13. Free asymmetric transverse vibration of polar orthotropic annular sector plate with thickness varying parabolically in radial direction

    Indian Academy of Sciences (India)

    R P Singh; S K Jain

    2004-10-01

    In the present paper, free asymmetric transverse vibrations of a nonuniform polar orthotropic annular sector plate, with parabolically varying thickness in the radial direction, have been studied on the basis of classical plate theory. The circular edges of the plate are elastically restrained against translation and rotation while the straight (radial) edges are simply-supported. Fourth-order linear differential equations with variable coefficients governing the motion have been solved by using the collocation interpolation technique with Chebyshev points as the interpolating nodes. Frequency parameters of the plate with flexible boundary conditions at the circular edges for some typical values of the taper parameters, the rigidity ratios and the radii ratio have been presented.

  14. High contrast all-optical diode based on direction-dependent optical bistability within asymmetric ring cavity

    Science.gov (United States)

    Xia, Xiu-Wen; Zhang, Xin-Qin; Xu, Jing-Ping; Yang, Ya-Ping

    2016-08-01

    We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 dB. Furthermore, its application as an all-optical logic AND gate is also discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274242, 11474221, and 11574229), the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. U1330203), and the National Key Basic Research Special Foundation of China (Grant Nos. 2011CB922203 and 2013CB632701).

  15. Asymmetric active nano-particles for directive near-field radiation

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Thorsen, Rasmus O.

    2016-01-01

    In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

  16. Activation of the prefrontal cortex by unilateral transcranial direct current stimulation leads to an asymmetrical effect on risk preference in frames of gain and loss.

    Science.gov (United States)

    Ye, Hang; Huang, Daqiang; Wang, Siqi; Zheng, Haoli; Luo, Jun; Chen, Shu

    2016-10-01

    Previous brain imaging and brain stimulation studies have suggested that the dorsolateral prefrontal cortex may be critical in regulating risk-taking behavior, although its specific causal effect on people's risk preference remains controversial. This paper studied the independent modulation of the activity of the right and left dorsolateral prefrontal cortex using various configurations of transcranial direct current stimulation. We designed a risk-measurement table and adopted a within-subject design to compare the same participant's risk preference before and after unilateral stimulation when presented with different frames of gain and loss. The results confirmed a hemispheric asymmetry and indicated that the right dorsolateral prefrontal cortex has an asymmetric effect on risk preference regarding frames of gain and loss. Enhancing the activity of the right dorsolateral prefrontal cortex significantly decreased the participants' degree of risk aversion in the gain frame, whereas it increased the participants' degree of risk aversion in the loss frame. Our findings provide important information regarding the impact of transcranial direct current stimulation on the risk preference of healthy participants. The effects observed in our experiment compared with those of previous studies provide further evidence of the effects of hemispheric and frame-dependent asymmetry. These findings may be helpful in understanding the neural basis of risk preference in humans, especially when faced with decisions involving possible gain or loss relative to the status quo.

  17. Existence of a directional Stokes drift in asymmetrical three-dimensional travelling gravity waves

    Science.gov (United States)

    Iooss, Gérard; Plotnikov, Pavel

    2009-09-01

    We consider periodic travelling gravity waves at the surface of an infinitely deep perfect fluid. The pattern is non-symmetric with respect to the propagation direction of the waves and we consider a general non-resonant situation. Defining a couple of amplitudes ɛ,ɛ along the basis of wave vectors which satisfy the dispersion relation, following Iooss and Plotnikov (2009), travelling waves exist with an asymptotic expansion in powers of ɛ,ɛ, for nearly all pair of angles made by the basic wave vectors with the critical propagation direction, and for values of the couple (ɛ12,ɛ22) in a subset of the plane, with asymptotic full measure at the origin. We prove the remarkable property that on the free surface, observed in the moving frame, the propagation direction of the waves differs from the asymptotic direction taken by fluid particles, by a small angle which is computed. To cite this article: G. Iooss, P. Plotnikov, C. R. Mecanique 337 (2009).

  18. Behavioral cardiology: current advances and future directions.

    Science.gov (United States)

    Rozanski, Alan

    2014-07-08

    Growing epidemiological evidence identifies key domains relevant to behavioral cardiology, including health behaviors, emotions, mental mindsets, stress management, social connectedness, and a sense of purpose. Each of these domains exists along a continuum, ranging from positive factors that promote health, to negative factors, which are pathophysiological. To date, there has been relatively little translation of this growing knowledge base into cardiology practice. Four initiatives are proposed to meet this challenge: 1) promulgating greater awareness of the potency of psychosocial risks factors; 2) overcoming a current "artificial divide" between conventional and psychosocial risk factors; 3) developing novel cost-effective interventions using Internet and mobile health applications, group-based counseling, and development of tiered-care behavioral management; and 4) in recognition that "one size does not fit all" with respect to behavioral interventions, developing specialists who can counsel patients in multidisciplinary fashion and use evidence-based approaches for promoting patient motivation and execution of health goals. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  19. Use of Direct Behavior Ratings to Collect Functional Assessment Data

    Science.gov (United States)

    Kilgus, Stephen P.; Kazmerski, Jennifer S.; Taylor, Crystal N.; von der Embse, Nathaniel P.

    2017-01-01

    The purpose of this investigation was to evaluate the utility of Direct Behavior Rating Single Item Scale (DBR-SIS) methodology in collecting functional behavior assessment data. Specific questions of interest pertained to the evaluation of the accuracy of brief DBR-SIS ratings of behavioral consequences and determination of the type of training…

  20. INFORMATIONAL CONSTRAINTS-DRIVEN ORGANIZATION IN GOAL-DIRECTED BEHAVIOR

    OpenAIRE

    SANDER G. VAN DIJK; DANIEL POLANI

    2013-01-01

    We study goal-directed behavior in the light of informationally constrained cognition. In a formal information-theoretical model, based on a description of goal-directed behavior as a family of Markov Decision Processes, we study lower bounds of constraints on the information about a goal needed to generate behavior that achieves such a goal at a certain level of optimality. We assume a working memory that operates on this minimally relevant goal information and study the necessary dynamics o...

  1. Plasma and Energetic Particle Behaviors During Asymmetric Magnetic Reconnection at the Magnetopause

    Science.gov (United States)

    Lee, S. H.; Zhang, H.; Zong, Q.-G.; Otto, A.; Sibeck, D. G.; Wang, Y.; Glassmeier, K.-H.; Daly, P.W.; Reme, H.

    2014-01-01

    The factors controlling asymmetric reconnection and the role of the cold plasma population in the reconnection process are two outstanding questions. We present a case study of multipoint Cluster observations demonstrating that the separatrix and flow boundary angles are greater on the magnetosheath than on the magnetospheric side of the magnetopause, probably due to the stronger density than magnetic field asymmetry at this boundary. The motion of cold plasmaspheric ions entering the reconnection region differs from that of warmer magnetosheath and magnetospheric ions. In contrast to the warmer ions, which are probably accelerated by reconnection in the diffusion region near the subsolar magnetopause, the colder ions are simply entrained by ??×?? drifts at high latitudes on the recently reconnected magnetic field lines. This indicates that plasmaspheric ions can sometimes play only a very limited role in asymmetric reconnection, in contrast to previous simulation studies. Three cold ion populations (probably H+, He+, and O+) appear in the energy spectrum, consistent with ion acceleration to a common velocity.

  2. Numerical investigation of polarization insensitive two-mode division (De)multiplexer based on an asymmetric directional coupler

    Science.gov (United States)

    Truong, Cao Dung; Trinh, M. Tuan; Dang, Hoai Bac; Nguyen, Van Tho

    2017-02-01

    We propose a polarization insensitive two-mode division (de)multiplexer based on a silicon-on-insulator platform operating with a broadband, low insertion and scattering loss, and small crosstalk. By using an asymmetric directional coupler, two-mode (de)multiplexing functions for both polarization TE and TM states can be realized by the numerical simulation. Simulated results using a three dimensional beam propagation method (3D-BPM) incorporated with an effective index method (EIM) show high performance of the device with an operation efficiency above 81.2% (i.e., insertion loss is less than 0.9 dB) in the range of ±5 nm around the central wavelength of 1550 nm. Fabrication tolerances also have proved suitability to current manufacture technologies for the planar waveguides. Besides a low scattering loss of the sidewall roughness and a little influence of dispersion, a small footprint can bring the device to applications of high bitrate and compact on-chip silicon photonic integrated circuits.

  3. Effect of n-type doping level on direct band gap electroluminescence intensity for asymmetric metal/Ge/metal diodes

    Science.gov (United States)

    Maekura, T.; Tanaka, K.; Motoyama, C.; Yoneda, R.; Yamamoto, K.; Nakashima, H.; Wang, D.

    2017-10-01

    The direct band gap electroluminescence (EL) intensity was investigated for asymmetric metal/Ge/metal diodes fabricated on n-type Ge with doping levels in the range of 4.0 × 1013-3.1 × 1018 cm-3. Up to a doping level of 1016 cm-3 order, commercially available (100) n-Ge substrates were used. To obtain a doping level higher than 1017 cm-3 order, which is commercially unavailable, n+-Ge/p-Ge structures were fabricated by Sb doping on p-type (100) Ge substrates with an in-diffusion at 600 °C followed by a push-diffusion at 700 °C-850 °C. The EL intensity was increased with increasing doping level up to 1.0 × 1018 cm-3. After that, it was decreased with a further increase in n-type doping level. This EL intensity decrease is explained by the decreased number of holes in the active region. One reason is the difficulty in hole injection through the PtGe/n-Ge contact due to the occurring of tunneling electron current. Another reason is the loss of holes caused by both the small thickness of n+-Ge layer and the existence of n+p junction.

  4. Direct Behavioral Consultation: Effects on Teachers' Praise and Student Disruptive Behavior

    Science.gov (United States)

    Dufrene, Brad A.; Lestremau, Lauren; Zoder-Martell, Kimberly

    2014-01-01

    Direct behavioral consultation is an extension of traditional behavioral consultation and focuses on assessment and training in the classroom during ongoing classroom activities. This study evaluated direct behavioral consultation services in two elementary alternative classrooms referred following a program evaluation in which data suggested…

  5. Transient flickering behavior in fringe-field switching liquid crystal mode analyzed by positional asymmetric flexoelectric dynamics.

    Science.gov (United States)

    Lee, Dong-Jin; Shim, Gyu-Yeop; Choi, Jun-Chan; Park, Ji-Sub; Lee, Joun-Ho; Baek, Ji-Ho; Choi, Hyun Chul; Ha, Yong Min; Ranjkesh, Amid; Kim, Hak-Rin

    2015-12-28

    We analyzed a transient blinking phenomenon in a fringe-field switching liquid crystal (LC) mode that occurred at the moment of frame change even in the optimized DC offset condition for minimum image flicker. Based on the positional dynamic behaviors of LCs by using a high-speed camera, we found that the transient blink is highly related to the asymmetric responses of the splay-bend transitions caused by the flexoelectric (FE) effect. To remove the transient blink, the elastic property adjustment of LCs was an effective solution because the FE switching dynamics between the splay-enhanced and bend-enhanced deformations are highly dependent on the elastic constants of LCs, which is the cause of momentary brightness drop.

  6. A Pavlovian Analysis of Goal-Directed Behavior.

    Science.gov (United States)

    Rescorla, Robert A.

    1987-01-01

    Analyzes associative structures underlying goal-directed behavior using well-developed techniques for studying Pavlovian conditioning. Identifies the roles of the stimulus, response, and reinforcer in instrumental learning. A response and its reinforcer must be associated for acquisition and maintenance of instrumental behavior. (Author/LHW)

  7. Asymmetric behavior in electrowetting of electrolyte solutions on graphene at the nanoscale: A molecular dynamics simulation

    Science.gov (United States)

    Taherian Tabasi, Fereshte; van der Vegt, Nico

    2015-03-01

    Using molecular dynamics simulations, electrowetting of aqueous solutions on graphene are studied. By doping the surface with the positive or negative charges, the counter-ions are adsorbed at the solid-liquid interface, and the co-ions are repelled from the interface, leading to the decrease of the solid-liquid surface tension and therefore the contact angle (known as electrowetting). Our simulation results show that at zero surface charge density, water molecules at the interface (located between the surface and first ionic layer) are mainly oriented parallel to the surface. However due to the smaller size of the hydrogen than the oxygen, there is a slight tendency of the water dipole moment to orient into the surface. On the charged surfaces, the orientation polarization of the interfacial water molecules are shown to be stronger on the negative surfaces than the positive ones. Such asymmetric orientation polarization of water leads to different screening of the graphene surface charge and therefore different contact angles of the solution on surfaces with opposite charges. Simulations results show more spreading of the liquid on the positively charged surfaces than the negative ones.

  8. Stereotypic circling behavior in mice with vestibular dysfunction: asymmetrical effects of intrastriatal microinjection of a dopamine agonist.

    Science.gov (United States)

    Ishiguro, Akio; Inagaki, Masumi; Kaga, Makiko

    2007-07-01

    Bronx Waltzer (bv) mouse, which has been used as a model of hearing and vestibular dysfunction, shows remarkable repetitive circling behavior. This study investigated whether the behavior is caused by the asymmetry of striatal function by observing the behavior of the bv mice following microinjection of dopamine D1 agonist, A68930 into the striatum ipsilaterally and contralaterally to the preferred direction of rotation separately. High dose of the drug induced opposite effects on ipsilateral rotations by the side of injections with statistical significance (p = .0026). These results suggested that the stereotypic circling behavior involves striatum and is based on striatal asymmetry.

  9. Neuroimaging of goal-directed behavior in midlife women.

    Science.gov (United States)

    Bosak, Kelly; Martin, Laura

    2014-01-01

    Motivational interventions to improve health behaviors based on conventional cognitive and behavioral theories have been extensively studied; however, advances in neuroimaging technology make it possible to assess the neurophysiological basis of health behaviors, such as physical activity. The goals of this approach are to support new interventions to achieve optimal outcomes. This study used functional magnetic resonance imaging (fMRI) to assess differences in brain responses in healthy weight to obese midlife women during a goal-directed decision task. Thirty nondiabetic, midlife (age 47-55 years) women with body mass index (BMI) ranging from 18.5 to 40 kg/m were recruited. A descriptive, correlational design was used to assess the relationship between brain activations and weight status. Participants underwent a goal-directed behavior task in the fMRI scanner consisting of a learning and implementation phase. The task was designed to assess both goal-directed and habitual behaviors. One participant was omitted from the analysis because of excessive motion (>4 mm), and six were omitted because of fewer than 50% correct responses on the exit survey. Four participants developed claustrophobia in the scanner and were disqualified from further participation. The remaining 19 participants were included in the final analysis. Brain responses while participants learned goal-directed behavior showed a positive correlation with BMI in the dorsomedial prefrontal cortex (dmPFC) and a negative correlation with BMI in the insula. During the implementation of goal-directed behavior, brain responses in the dorsolateral prefrontal cortex (dlPFC) negatively correlated with BMI. These results indicate that overweight women activate regions associated with cognitive control to a greater degree than healthy weight women during goal-directed learning. The brain regions activated (dmPFC, dlPFC, insula) are associated with cognitive control and self-regulation. On the other hand

  10. Viscoelasticity and nonlinear simple shear flow behavior of an entangled asymmetric exact comb polymer solution

    KAUST Repository

    Snijkers, F.

    2016-03-31

    We report upon the characterization of the steady-state shear stresses and first normal stress differences as a function of shear rate using mechanical rheometry (both with a standard cone and plate and with a cone partitioned plate) and optical rheometry (with a flow-birefringence setup) of an entangled solution of asymmetric exact combs. The combs are polybutadienes (1,4-addition) consisting of an H-skeleton with an additional off-center branch on the backbone. We chose to investigate a solution in order to obtain reliable nonlinear shear data in overlapping dynamic regions with the two different techniques. The transient measurements obtained by cone partitioned plate indicated the appearance of overshoots in both the shear stress and the first normal stress difference during start-up shear flow. Interestingly, the overshoots in the start-up normal stress difference started to occur only at rates above the inverse stretch time of the backbone, when the stretch time of the backbone was estimated in analogy with linear chains including the effects of dynamic dilution of the branches but neglecting the effects of branch point friction, in excellent agreement with the situation for linear polymers. Flow-birefringence measurements were performed in a Couette geometry, and the extracted steady-state shear and first normal stress differences were found to agree well with the mechanical data, but were limited to relatively low rates below the inverse stretch time of the backbone. Finally, the steady-state properties were found to be in good agreement with model predictions based on a nonlinear multimode tube model developed for linear polymers when the branches are treated as solvent.

  11. Behavioral plasticity mediates asymmetric competition between invasive wasps and native ants.

    Science.gov (United States)

    Grangier, Julien; Lester, Philip J

    2012-03-01

    One of the most successful invasive species is the common wasp, Vespula vulgaris. We recently reported how foragers of this species have adopted previously unknown interference behavior when competing for food with native ants. Picking their opponents up in their mandibles, flying backward and dropping them some distance away from the disputed resource, wasps were shown to efficiently deal with a yet aggressive competitor and to modulate this behavior according to circumstances. Here we further discuss the nature and functioning of this unusual strategy. We first highlight the questions this interaction raises regarding the competitive advantages offered by asymmetries in body size and flight ability. Then, we argue that this study system illustrates the important role of behavioral plasticity in biological invasions; not only in the success of invaders but also in the ability of native species to coexist with these invaders.

  12. The effect of inclination angle on the plastic deformation behavior of bicrystalline silver nanowires with Σ3 asymmetric tilt grain boundaries

    Science.gov (United States)

    Yuan, Lin; Jing, Peng; Shan, Debin; Guo, Bin

    2017-01-01

    Atomistic simulations were used to investigate the plastic deformation behavior of bicrystalline silver nanowires with Σ3 asymmetric tilt grain boundaries at 0.1 K. The calculated grain boundary energies of Σ3 asymmetric tilt grain boundaries corresponded well with the energies measured in experiments and predicted by the theoretical description. The Σ3 asymmetric tilt grain boundaries with low inclination angles were composed of a replication of twin boundary segments separated by small ledges. The results demonstrated that the combination effect of Schmid factor and non-Schmid factors could explain dislocations emission into grain 1 only in models with low inclination angles (Ф nanocrystalline materials and provide insights into the synthesis of nanocrystalline materials with superior strength and ductility.

  13. Direct Observation of Teacher and Student Behavior in School Settings: Trends, Issues and Future Directions

    Science.gov (United States)

    Lewis, Timothy J.; Scott, Terrance M.; Wehby, Joseph H.; Wills, Howard P.

    2014-01-01

    Across the modern history of the field of special education and emotional/behavioral disorders (EBD), direct observation of student and educator behavior has been an essential component of the diagnostic process, student progress monitoring, and establishing functional and statistical relationships within research. This article provides an…

  14. Significance of rotating ground motions on nonlinear behavior of symmetric and asymmetric buildings in near fault sites

    Science.gov (United States)

    Kalkan, Erol; ,

    2012-01-01

    Building codes in the U.S. require at least two horizontal ground motion components for three-dimensional (3D) response history analysis (RHA) of structures. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all non-redundant rotation angles. This assumption is examined here using 3D computer models of a single-story structure having symmetric (that is, torsionally-stiff) and asymmetric (that is, torsionally flexible) layouts subjected to an ensemble of bi-directional near-fault strong ground motions with and without apparent velocity pulses. In this parametric study, the elastic vibration period of the structures is varied from 0.2 to 5 seconds, and yield strength reduction factors R is varied from a value that leads to linear-elastic design to 3 and 5. The influence that the rotation angle of the ground motion has on several engineering demand parameters (EDPs) is examined in linear-elastic and nonlinear-inelastic domains to form a benchmark for evaluating the use of the FN/FP directions as well as the maximum-direction (MD) ground motion, a new definition of horizontal ground motions for use in the seismic design of structures according to the 2009 NEHRP Provisions and Commentary.

  15. Adult-Directed and Peer-Directed Respect for Authority: Relationships With Aggressive and Manipulative Behavior.

    Science.gov (United States)

    Clemans, Katherine H; Graber, Julia A; Bettencourt, Amie F

    2012-09-01

    This study investigated whether respect for adult and peer authority are separate attitudes which have distinct relationships with aggressive and manipulative behavior. Items assessing admiration for and obedience toward parents, teachers, popular students, and friend group leaders were administered to 286 middle school students (M age = 12.6 yrs). Factor analysis revealed two primary factors which corresponded to adult-directed and peer-directed respect orientations. Results suggested that adult-directed respect was associated with lower levels of aggression and social manipulation, whereas peer-directed respect was associated with higher levels of these behaviors. The role of peer-directed respect as a risk factor for negative social behavior in adolescence is discussed.

  16. More on contamination: the use of asymmetric molecular behavior to identify authentic ancient human DNA

    DEFF Research Database (Denmark)

    Malmström, Helena; Svensson, Emma M; Gilbert, M Thomas P;

    2007-01-01

    the reliability of one of the proposed criteria, that of appropriate molecular behavior. Using real-time polymerase chain reaction (PCR) and pyrosequencing, we have quantified the relative levels of authentic aDNA and contaminant human DNA sequences recovered from archaeological dog and cattle remains. In doing....... Furthermore, we find that there is a substantial increase in the relative proportions of authentic DNA to contaminant DNA as the PCR target fragment size is decreased. We therefore conclude that the degradation pattern in aDNA provides a quantifiable difference between authentic aDNA and modern contamination...

  17. Use of Direct Behavior Ratings to Collect Functional Assessment Data.

    Science.gov (United States)

    Kilgus, Stephen P; Kazmerski, Jennifer S; Taylor, Crystal N; von der Embse, Nathaniel P

    2016-05-30

    The purpose of this investigation was to evaluate the utility of Direct Behavior Rating Single Item Scale (DBR-SIS) methodology in collecting functional behavior assessment data. Specific questions of interest pertained to the evaluation of the accuracy of brief DBR-SIS ratings of behavioral consequences and determination of the type of training necessary to support such accuracy. Undergraduate student participants (N = 213; 62.0% male; 62.4% White) viewed video clips of students in a classroom setting, and then rated both disruptive behavior and 4 consequences of that behavior (i.e., adult attention, peer attention, escape/avoidance, and access to tangibles/activities). Results indicated training with performance feedback was necessary to support the generation of accurate disruptive behavior and consequence ratings. Participants receiving such support outperformed students in training-only, pretest-posttest, and posttest-only groups for disruptive behavior and all 4 DBR-SIS consequence targets. Future directions for research and implications for practice are discussed, including how teacher ratings may be collected along with other forms of assessment (e.g., progress monitoring) within an efficient Tier 2 assessment model. (PsycINFO Database Record

  18. Scaling behavior of the directed percolation universality class

    Energy Technology Data Exchange (ETDEWEB)

    Luebeck, S. [Theoretische Physik, Universitaet Duisburg-Essen, 47048 Duisburg (Germany)]. E-mail: sven@thp.uni-duisburg.de; Willmann, R.D. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany)]. E-mail: r.willmann@fz-juelich.de

    2005-07-11

    In this work we consider five different lattice models which exhibit continuous phase transitions into absorbing states. By measuring certain universal functions, which characterize the steady state as well as the dynamical scaling behavior, we present clear numerical evidence that all models belong to the universality class of directed percolation. Since the considered models are characterized by different interaction details the obtained universal scaling plots are an impressive manifestation of the universality of directed percolation.

  19. Physical characterization of amorphous In-Ga-Zn-O thin-film transistors with direct-contact asymmetric graphene electrode

    Directory of Open Access Journals (Sweden)

    Jaewook Jeong

    2014-09-01

    Full Text Available High performance a-IGZO thin-film transistors (TFTs are fabricated using an asymmetric graphene drain electrode structure. A-IGZO TFTs (channel length = 3 μm were successfully demonstrated with a saturation field-effect mobility of 6.6 cm2/Vs without additional processes between the graphene and a-IGZO layer. The graphene/a-IGZO junction exhibits Schottky characteristics and the contact property is affected not only by the Schottky barrier but also by the parasitic resistance from the depletion region under the graphene electrode. Therefore, to utilize the graphene layer as S/D electrodes for a-IGZO TFTs, an asymmetric electrode is essential, which can be easily applied to the conventional pixel electrode structure.

  20. Direct and post-synthesis incorporation of chiral metallosalen catalysts into metal-organic frameworks for asymmetric organic transformations.

    Science.gov (United States)

    Xi, Weiqin; Liu, Yan; Xia, Qingchun; Li, Zijian; Cui, Yong

    2015-09-01

    Two chiral porous metal-organic frameworks (MOFs) were constructed from [VO(salen)]-derived dicarboxylate and dipyridine bridging ligands. After oxidation of V(IV) to V(V) , they were found to be highly effective, recyclable, and reusable heterogeneous catalysts for the asymmetric cyanosilylation of aldehydes with up to 95 % ee. Solvent-assisted linker exchange (SALE) treatment of the pillared-layer MOF with [Cr(salen)Cl]- or [Al(salen)Cl]-derived dipyridine ligands led to the formation of mixed-linker metallosalen-based frameworks and incorporation of [Cr(salen)] enabled its use as a heterogeneous catalyst in the asymmetric epoxide ring-opening reaction.

  1. A tailor-made chimeric thiamine diphosphate dependent enzyme for the direct asymmetric synthesis of (S)-benzoins.

    Science.gov (United States)

    Westphal, Robert; Vogel, Constantin; Schmitz, Carlo; Pleiss, Jürgen; Müller, Michael; Pohl, Martina; Rother, Dörte

    2014-08-25

    Thiamine diphosphate dependent enzymes are well known for catalyzing the asymmetric synthesis of chiral α-hydroxy ketones from simple prochiral substrates. The steric and chemical properties of the enzyme active site define the product spectrum. Enzymes catalyzing the carboligation of aromatic aldehydes to (S)-benzoins have not so far been identified. We were able to close this gap by constructing a chimeric enzyme, which catalyzes the synthesis of various (S)-benzoins with excellent enantiomeric excess (>99%) and very good conversion.

  2. Is there a relationship between preferred posture and positioning in early life and the direction of subsequent asymmetrical postural deformity in non ambulant people with cerebral palsy?

    Science.gov (United States)

    Porter, David; Michael, Shona; Kirkwood, Craig

    2008-09-01

    It has been suggested that asymmetrical positioning of an infant with reduced mobility may lead to postural deformity becoming established over time. However, evidence to support or question this line of thinking is lacking. Therefore, the aim of this retrospective cohort study was to test the association between asymmetrical positioning in the first 12 months of life and the subsequent direction of postural deformity in non-ambulant people with cerebral palsy. The direction of scoliosis, pelvic obliquity and windswept hip pattern and also the side of unilateral hip subluxation/dislocation were determined for 246 young people ranging in age from 1 year and 2 months to 19 years (median age 10 years and 3 months). Parents/carers of the participants were interviewed to establish holding and feeding positions and preferred lying posture adopted in early life. Univariate analyses and multivariate logistic regression analyses were carried out. The study provided evidence of an association between asymmetrical lying posture adopted in the first year of life and the direction of the subsequent pattern of postural deformity. If the child's head had been rotated to the right during supine lying, it was more likely that the scoliosis would be convex to the left, pelvic obliquity would be lower on the left, windswept hip pattern would be to the right and hip subluxation/dislocation would occur on the left. The likelihood of the deformities occurring in the same direction was also increased if consistent side lying on the right had been preferred. Clinicians should be aware of positioning for children with severe disabilities particularly those who prefer supine lying with their head rotated to the side and those who prefer consistent side lying.

  3. Owners' direct gazes increase dogs' attention-getting behaviors.

    Science.gov (United States)

    Ohkita, Midori; Nagasawa, Miho; Kazutaka, Mogi; Kikusui, Takefumi

    2016-04-01

    This study examined whether dogs gain information about human's attention via their gazes and whether they change their attention-getting behaviors (i.e., whining and whimpering, looking at their owners' faces, pawing, and approaching their owners) in response to their owners' direct gazes. The results showed that when the owners gazed at their dogs, the durations of whining and whimpering and looking at the owners' faces were longer than when the owners averted their gazes. In contrast, there were no differences in duration of pawing and likelihood of approaching the owners between the direct and averted gaze conditions. Therefore, owners' direct gazes increased the behaviors that acted as distant signals and did not necessarily involve touching the owners. We suggest that dogs are sensitive to human gazes, and this sensitivity may act as attachment signals to humans, and may contribute to close relationships between humans and dogs.

  4. An Environmentally Benign System for Synthesis of β-Hydroxylketones: L-Histidine Asymmetrically Catalyzed Direct Aldol Reactions in Aqueous Micelle and Water-like Media

    Institute of Scientific and Technical Information of China (English)

    PENG Yi-Yuan; PENG Shu-Jun; DING Qiu-Ping; WANG Qi; CHENG Jin-Pei

    2007-01-01

    The first histidine catalyzed direct aldol reactions of ketones with nitrobenzaldehydes in water and in poly(ethylene glycol) (PEG) were reported. It reveals that histidine is a good aldol catalyst for synthesis of β-hydroxylketones in water and in PEG, giving good to excellent yields of the respective products. Better enantioand regioselectivity were achieved using low molecular weight PEG as the media. The results show that histidine and PEG-200 or -300 may constitute a promising environmentally benign system for asymmetric synthesis of β-hydroxylketones.

  5. Does asymmetric correlation affect portfolio optimization?

    Science.gov (United States)

    Fryd, Lukas

    2017-07-01

    The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

  6. Impact of pharmacists' directive guidance behaviors on patient satisfaction.

    Science.gov (United States)

    Singhal, Puneet K; Gupchup, Gireesh V; Raisch, Dennis W; Schommer, Jon C; Holdsworth, Mark T

    2002-01-01

    To determine the impact of directive guidance (DG) behaviors by pharmacists on patient satisfaction with pharmaceutical care services. DG behaviors are social support behaviors and include such activities as supplying information about medications and providing encouragement and feedback regarding drug therapy. Cross-sectional observational study using a self-administered survey. Two university-affiliated ambulatory care clinics, two chain pharmacies, and one independent pharmacy. One hundred sixty patients with a chronic disease (e.g., asthma, hypertension, diabetes). Patient satisfaction with pharmaceutical care services. A total of 160 completed questionnaires were collected from patients at 5 sites. Overall, patients patronizing ambulatory care clinics perceived higher rates of DG behaviors and were more satisfied with pharmaceutical care services, compared with patients in community pharmacies (P < .05). The hierarchical regression model was significant (F(13,112) = 4.9091, P < .001). DG behaviors explained 32.4% (P < .001) of the variance in patient satisfaction with pharmaceutical care services. Higher rates of DG behaviors by pharmacists are associated with greater patient satisfaction with pharmaceutical care services.

  7. Goal-directed, habitual and Pavlovian prosocial behavior.

    Science.gov (United States)

    Gęsiarz, Filip; Crockett, Molly J

    2015-01-01

    Although prosocial behaviors have been widely studied across disciplines, the mechanisms underlying them are not fully understood. Evidence from psychology, biology and economics suggests that prosocial behaviors can be driven by a variety of seemingly opposing factors: altruism or egoism, intuition or deliberation, inborn instincts or learned dispositions, and utility derived from actions or their outcomes. Here we propose a framework inspired by research on reinforcement learning and decision making that links these processes and explains characteristics of prosocial behaviors in different contexts. More specifically, we suggest that prosocial behaviors inherit features of up to three decision-making systems employed to choose between self- and other- regarding acts: a goal-directed system that selects actions based on their predicted consequences, a habitual system that selects actions based on their reinforcement history, and a Pavlovian system that emits reflexive responses based on evolutionarily prescribed priors. This framework, initially described in the field of cognitive neuroscience and machine learning, provides insight into the potential neural circuits and computations shaping prosocial behaviors. Furthermore, it identifies specific conditions in which each of these three systems should dominate and promote other- or self- regarding behavior.

  8. Goal-directed, habitual and Pavlovian prosocial behavior

    Directory of Open Access Journals (Sweden)

    Filip eGęsiarz

    2015-05-01

    Full Text Available Although prosocial behaviors have been widely studied across disciplines, the mechanisms underlying them are not fully understood. Evidence from psychology, biology and economics suggests that prosocial behaviors can be driven by a variety of seemingly opposing factors: altruism or egoism, intuition or deliberation, inborn instincts or learned dispositions, and utility derived from actions or their outcomes. Here we propose a framework inspired by research on reinforcement learning and decision making that links these processes and explains characteristics of prosocial behaviors in different contexts. More specifically, we suggest that prosocial behaviors inherit features of up to three decision-making systems employed to choose between self- and other- regarding acts: a goal-directed system that selects actions based on their predicted consequences, a habitual system that selects actions based on their reinforcement history, and a Pavlovian system that emits reflexive responses based on evolutionarily prescribed priors. This framework, initially described in the field of cognitive neuroscience and machine learning, provides insight into the potential neural circuits and computations shaping prosocial behaviors. Furthermore, it identifies specific conditions in which each of these three systems should dominate and promote other- or self- regarding behavior.

  9. Recrystallizaiton Behavior of Directionally Solidified DZ4 Superalloy

    Institute of Scientific and Technical Information of China (English)

    Li Yun-ju; Zhang Wei-fang; Tao Chun-hu

    2004-01-01

    This article investigated effects of degrees of deformation, heat treatment temperatures and holding times on the recrystallization behavior of directionally solidified DZ4 superalloy. The results showed that, recrystallization of DZ4 superalloy could take place during solution heat treatment after certain degrees of cold work and depths of recrystallization increased with increasing degrees of deformation and heat treatment temperature. At the temperature below γ' solvus,prolonged holding times did not play an important role in improving recrystallization depths. Moreover, prevention measures for recrystallization of directionally solidified blades were given.

  10. Asymmetric behavior of the B$(E2 \\uparrow; 0^+ \\rightarrow 2^+)$ values in $^{104-130}$Sn and Generalized Seniority

    CERN Document Server

    Maheshwari, Bhoomika; Singh, Balraj

    2016-01-01

    We explain the asymmetric behavior of the freshly evaluated B$(E2\\uparrow;0^+\\rightarrow2^+)$ values across the even-even Sn-isotopes by using the concept of generalized seniority. The dip in the B$(E2)$ values near $^{116}$Sn is understood in terms of a change in the dominant orbits before and after the mid shell, which also explains the presence of asymmetric peaks in the B$(E2)$ values. This approach helps in deciding the active valence spaces for a given set of isotopes, and single out the most useful truncation scheme for Large Scale Shell Model (LSSM) calculations. The LSSM calculations so guided by generalized seniority are also able to reproduce the experimental data on B$(E2)\\uparrow$ values quite well.

  11. Chirality imprinting and direct asymmetric reaction screening using a stereodynamic Brønsted/Lewis acid receptor

    Science.gov (United States)

    Bentley, Keith W.; Proano, Daysi; Wolf, Christian

    2016-08-01

    Molecular recognition, activation and dynamic self-assembly with Brønsted and Lewis acids play a central role across the chemical sciences including catalysis, crystal engineering, supramolecular architectures and drug design. Despite this general advance, the utilization of the corresponding binding motifs for fast and robust quantitative chemosensing of chiral compounds in a complicate matrix has remained challenging. Here we show that a stereodynamic probe carrying complementary boronic acid and urea units achieves this goal with hydroxy carboxylic acids. Synergistic dual-site binding and instantaneous chirality imprinting result in characteristic ultraviolet and CD readouts that allow instantaneous determination of the absolute configuration, enantiomeric excess and concentration of the target compound even in complex mixtures. The robustness and practicality of this strategy for high-throughput screening purposes is demonstrated. Comprehensive sensing of only 0.5 mg of a crude reaction mixture of an asymmetric reduction eliminates cumbersome work-up protocols and minimizes analysis time, labour and waste production.

  12. Direct vector controlled six-phase asymmetrical induction motor with power balanced space vector PWM multilevel operation

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Grandi, Gabriele; Ojo, Joseph Olorunfemi

    2016-01-01

    In this paper, a six-phase (asymmetrical) machine is investigated, 300 phase displacement is set between two three-phase stator windings keeping deliberately in open-end configuration. Power supply consists of four classical three-phase voltage inverters (VSIs), each one connected to the open......) approach was adopted for each couple of VSIs to operate as multilevel output voltage generators. The proposed power sharing algorithm is verified for the ac drive system by observing the dynamic behaviours in different set conditions by complete simulation modelling in software (Matlab....../Simulink-PLECS) and the results are provided in this paper. Furthermore, harmonic components are shown in each subspace and analysed with Fourier spectrum to confirm the smooth torque propagation with free of harmonic components. The numerical simulation results provided in this paper are closely matching with theoretical...

  13. Global behavior of dynamical agents in directed network

    Institute of Scientific and Technical Information of China (English)

    Hongwang YU; Yufan ZHENG

    2009-01-01

    This paper investigates the global behavior of controlled dynamical agents in directed networks.The agents are Lyapunov stable,are distributed in a line,and communicate through a directed network.The communication topology of the network is characterized by a directed graph and the control protocol is designed in simple linear decentralized feedback law.We study the different conditions under which agents will achieve aggregation,and critical and divergent trajectories,respectively.Our investigation on the dynamical agent system under network is extended to the time-delay network case.Furthermore,we study the case with two pre-specified virtual leaders in the system.Numerical simulations are given and demonstrate that our theoretical results are effective.

  14. Metal particle's precipitation behavior in direct reading ferrography precipitator tube

    Institute of Scientific and Technical Information of China (English)

    尹凤福; 李谋渭

    2004-01-01

    A new metal particle monitoring instrument was developed by improving the traditional direct reading ferrography. The precipitation behaviors of sub-magnetic particles, magnetic particles, and the mixture of these particles were examined with the instrument. The results show that the precipitation behavior of sub-magnetic metal particles of copper and aluminum is not random as it was believed previously. The sub-magnetic particles show a distribution in the precipitator tube, almost the same as the deposition curves as the magnetic particles have. The deposition amount of particles is increased in the oil which consists of several different kinds of particles. On the base of these experiments, a new index used for the total quantity of wear was redefined.

  15. Combination of Metal Coordination Tetrahedra and Asymmetric Coordination Geometries of Sb(III) in the Organically Directed Chalcogenidometalates: Structural Diversity and Ion-exchange Properties.

    Science.gov (United States)

    Feng, Mei-Ling; Wang, Kai-Yao; Huang, Xiao-Ying

    2016-04-01

    Chalcogenidometalates exhibit rich and diverse structures and properties applicable to ion exchange, thermoelectrics, photocatalysis, nonlinear optics, and so on. This personal account summarizes our recent progress in constructing chalcogenidometalates by combining metal coordination tetrahedra and the asymmetric coordination geometries of Sb(3+) in the presence of organic species (typically organic amines and metal-organic amine complexes), which has been demonstrated as an effective strategy for synthesizing chalcogenidometalates with diversified structures and interesting properties. The linkage modes of asymmetric SbQn (n = 3, 4) geometries and group 13 (or 14) metal coordination tetrahedra are analyzed, and the secondary building units (SBUs), with different compositions and architectures, are clarified. The crucial role and function of organic species in the formation of chalcogenidometalates are explored, with an emphasis on their powerful structure-directing features. In particular, some chalcogenidometalates in this family exhibit excellent ion-exchange properties for Cs(+) and/or Sr(2+) ions; the factors affecting ion-exchange properties are discussed to understand the underlying ion-exchange mechanism.

  16. Direct behavioral evidence for retronasal olfaction in rats.

    Directory of Open Access Journals (Sweden)

    Shree Hari Gautam

    Full Text Available The neuroscience of flavor perception is becoming increasingly important to understand abnormal feeding behaviors and associated chronic diseases such as obesity. Yet, flavor research has mainly depended on human subjects due to the lack of an animal model. A crucial step towards establishing an animal model of flavor research is to determine whether the animal uses the retronasal mode of olfaction, an essential element of flavor perception. We designed a go- no go behavioral task to test the rat's ability to detect and discriminate retronasal odorants. In this paradigm, tasteless aqueous solutions of odorants were licked by water-restricted head-fixed rats from a lick spout. Orthonasal contamination was avoided by employing a combination of a vacuum around the lick-spout and blowing clean air toward the nose. Flow models support the effectiveness of both approaches. The licked odorants were successfully discriminated by rats. Moreover, the tasteless odorant amyl acetate was reliably discriminated against pure distilled water in a concentration-dependent manner. The results from this retronasal odor discrimination task suggest that rats are capable of smelling retronasally. This direct behavioral evidence establishes the rat as a useful animal model for flavor research.

  17. Direct CP Violation in Charmless Hadronic B-Meson Decays at the PEP-II Asymmetric B-Meson Factory

    Energy Technology Data Exchange (ETDEWEB)

    Telnov, Alexandre Valerievich; /UC, Berkeley

    2005-05-06

    The study of the quark transition b {yields} s{bar s}s, which is a pure loop-level (''penguin'') process leading to several B-meson-decay final states, most notably {phi}K, is arguably the hottest topic in B-meson physics today. The reason is the sensitivity of the amplitudes and the CP-violating asymmetries in such processes to physics beyond the Standard Model. By performing these measurements, we improve our understanding of the phenomenon of combined-parity (CP) violation, which is believed to be responsible for the dominance of matter over antimatter in our Universe. Here, we present measurements of branching fractions and charge asymmetries in the decays B{sup +} {yields} {phi}K{sup +} and B{sup 0} {yields} {phi}K{sup 0} in a sample of approximately 89 million B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B-meson Factory at SLAC. We determine {Beta}(B{sup +} {yields} {phi}K{sup +}) = (10.0{sub -0.8}{sup +0.9} {+-} 0.5) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}K{sup 0}) = (8.4{sub -1.3}{sup +1.5} {+-} 0.5) x 10{sup -6}, where the first error is statistical and the second is systematic. Additionally, we measure the CP-violating charge asymmetry {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) = 0.04 {+-} 0.09 {+-} 0.01, with a 90% confidence-level interval of [-0.10, 0.18], and set an upper limit on the CKM- and color-suppressed decay B{sup +} {yields} {phi}{pi}{sup +}, {Beta}(B{sup +} {yields} {phi}{pi}{sup +}) < 0.41 x 10{sup -6} (at the 90% confidence level). Our results are consistent with the Standard Model, which predicts {Alpha}{sub CP}(B{sup {+-}} {yields} {phi}K{sup {+-}}) {approx}< 1% and {Beta}(B {yields} {phi}{tau}) << 10{sup -7}. Since many models of physics beyond the Standard Model introduce additional loop diagrams with new heavy particles and new CP-violating phases that would contribute to these decays, potentially making {Alpha}{sub CP} (B{sup {+-}} {yields} {phi

  18. Investigation of temperature-dependent asymmetric degradation behavior induced by hot carrier effect in oxygen ambiance in In–Ga–Zn-O thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bo-Wei [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Chang, Ting-Chang [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Hung, Yu-Ju [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Hsieh, Tien-Yu [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Tsai, Ming-Yen [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Liao, Po-Yung [Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Tsai, Wu-Wei; Chiang, Wen-Jen; Yan, Jing-Yi [Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Hsinchu, 31040, Taiwan (China)

    2014-12-01

    The effects of oxygen ambiance on electrical characteristic degradation phenomena in a-InGaZnO thin film transistor with different biases and temperatures are investigated. It can be found that oxygen is substantially adsorbed on the backchannel and results in device instabilities during positive gate bias stress. However, visible light irradiation is found to desorb the adsorbed oxygen ions and this verifies that oxygen dominates the degradation behavior. Moreover, comparing with that in vacuum, hot-carrier stress in oxygen ambiance leads to an extra potential barrier height near the drain side due to oxygen adsorption and causes asymmetric degradation. Furthermore, the asymmetric degradation behavior after hot-carrier stress in oxygen ambiance is suppressed at high temperature due to temperature-induced oxygen desorption or heat-induced holes injecting into the gate insulator. - Highlights: • Oxygen adsorbing will occur beneath the active layer under persistent positive gate bias. • Oxygen desorbing under illumination was verified from the recovery of transfer curves. • Additional barrier height is generated after hot-carrier stress because of oxygen adsorption. • The amount of hot-carrier degradation in oxygen ambience will decrease as temperature elevating.

  19. Striatal direct and indirect pathways control decision-making behavior

    Directory of Open Access Journals (Sweden)

    Tom eMacpherson

    2014-11-01

    Full Text Available Despite our ever-changing environment, animals are remarkable adept at selecting courses of action that are predictive of optimal outcomes. While requiring the contribution of a number of brain regions, a vast body of evidence implicates striatal mechanisms of associative learning and action selection to be critical to this ability. While numerous models of striatal-based decision-making have been developed, it is only recently that we have begun to understand the precise contributions of specific subpopulations of striatal neurons. Studies utilizing contemporary cell-type-specific technologies indicate that striatal output pathways play distinct roles in controlling goal-directed and social behaviors. Here we review current models of striatal-based decision-making, discuss recent developments in defining the functional roles of striatal output pathways, and assess how striatal dysfunction may contribute to the etiology of various neuropathologies.

  20. Direct behavioral and neurophysiological evidence for retronasal olfaction in mice.

    Directory of Open Access Journals (Sweden)

    Michelle R Rebello

    Full Text Available The neuroscience of flavor perception is hence becoming increasingly important to understand food flavor perception that guides food selection, ingestion and appreciation. We recently provided evidence that rats can use the retronasal mode of olfaction, an essential element of human flavor perception. We showed that in rats, like humans, odors can acquire a taste. We and others also defined how the input of the olfactory bulb (OB -not functionally imageable in humans- codes retronasal smell in anesthetized rat. The powerful awake transgenic mouse, however, would be a valuable additional model in the study of flavor neuroscience. We used a go/no-go behavioral task to test the mouse's ability to detect and discriminate the retronasal odor amyl acetate. In this paradigm a tasteless aqueous odor solution was licked by water-restricted head-fixed mice from a lick spout. Orthonasal contamination was avoided. The retronasal odor was successfully discriminated by mice against pure distilled water in a concentration-dependent manner. Bulbectomy removed the mice's ability to discriminate the retronasal odor but not tastants. The OB showed robust optical calcium responses to retronasal odorants in these awake mice. These results suggest that mice, like rats, are capable of smelling retronasally. This direct neuro-behavioral evidence establishes the mouse as a useful additional animal model for flavor research.

  1. Direct Behavioral and Neurophysiological Evidence for Retronasal Olfaction in Mice

    Science.gov (United States)

    Rebello, Michelle R.; Kandukuru, Padma; Verhagen, Justus V.

    2015-01-01

    The neuroscience of flavor perception is hence becoming increasingly important to understand food flavor perception that guides food selection, ingestion and appreciation. We recently provided evidence that rats can use the retronasal mode of olfaction, an essential element of human flavor perception. We showed that in rats, like humans, odors can acquire a taste. We and others also defined how the input of the olfactory bulb (OB) -not functionally imageable in humans- codes retronasal smell in anesthetized rat. The powerful awake transgenic mouse, however, would be a valuable additional model in the study of flavor neuroscience. We used a go/no-go behavioral task to test the mouse's ability to detect and discriminate the retronasal odor amyl acetate. In this paradigm a tasteless aqueous odor solution was licked by water-restricted head-fixed mice from a lick spout. Orthonasal contamination was avoided. The retronasal odor was successfully discriminated by mice against pure distilled water in a concentration-dependent manner. Bulbectomy removed the mice's ability to discriminate the retronasal odor but not tastants. The OB showed robust optical calcium responses to retronasal odorants in these awake mice. These results suggest that mice, like rats, are capable of smelling retronasally. This direct neuro-behavioral evidence establishes the mouse as a useful additional animal model for flavor research. PMID:25675095

  2. Pyrrolidinyl-sulfamide derivatives as a new class of bifunctional organocatalysts for direct asymmetric Michael addition of cyclohexanone to nitroalkenes.

    Science.gov (United States)

    Chen, Jia-Rong; Fu, Liang; Zou, You-Quan; Chang, Ning-Jie; Rong, Jian; Xiao, Wen-Jing

    2011-07-21

    A series of chiral pyrrolidinyl-sulfamide derivatives have been identified as efficient bifunctional organocatalysts for the direct Michael addition of cyclohexanone to a wide range of nitroalkenes. The desired Michael adducts were obtained in high chemical yields and excellent stereoselectivities (up to 99/1 dr and 95% ee).

  3. Critical endpoint behavior in an asymmetric Ising model: application of Wang-Landau sampling to calculate the density of states.

    Science.gov (United States)

    Tsai, Shan-Ho; Wang, Fugao; Landau, D P

    2007-06-01

    Using the Wang-Landau sampling method with a two-dimensional random walk we determine the density of states for an asymmetric Ising model with two- and three-body interactions on a triangular lattice, in the presence of an external field. With an accurate density of states we were able to map out the phase diagram accurately and perform quantitative finite-size analyses at, and away from, the critical endpoint. We observe a clear divergence of the curvature of the spectator phase boundary and of the magnetization coexistence diameter derivative at the critical endpoint, and the exponents for both divergences agree well with previous theoretical predictions.

  4. Critical endpoint behavior in an asymmetric Ising model: Application of Wang-Landau sampling to calculate the density of states

    Science.gov (United States)

    Tsai, Shan-Ho; Wang, Fugao; Landau, D. P.

    2007-06-01

    Using the Wang-Landau sampling method with a two-dimensional random walk we determine the density of states for an asymmetric Ising model with two- and three-body interactions on a triangular lattice, in the presence of an external field. With an accurate density of states we were able to map out the phase diagram accurately and perform quantitative finite-size analyses at, and away from, the critical endpoint. We observe a clear divergence of the curvature of the spectator phase boundary and of the magnetization coexistence diameter derivative at the critical endpoint, and the exponents for both divergences agree well with previous theoretical predictions.

  5. A Study on the Behavior of Volatility in Saudi Arabia Stock Market Using Symmetric and Asymmetric GARCH Models

    Directory of Open Access Journals (Sweden)

    Ahmed Shamiri

    2012-01-01

    Full Text Available Problem statement: This study examines several stylized facts (heavy-tailedness, leverage effect and persistence in volatility of stock price returns exploiting symmetric and asymmetric GARCH family models for Saudi Arabia. Approach: This study is carried out using closing stock market prices over 15 years covering the period 1 January 1994 to 31 March 2009. The sample period is divided into three sub-periods according to the local crisis in 2006. Results: The results reveal that asymmetric models with heavy tailed densities improve overall estimation of the conditional variance equation. Moreover, we find that AR (1-GJR GARCH model with Student-t outperform the other models during and before the local crisis in 2006, while AR (1-GARCH model with GED exhibits a better performance after the crisis. Furthermore, the findings reveal the existence of leverage effect at 1 percent significance level. Conclusion/Recommendations: Finally, the volatility persistent in the samples during and after crises decreases in all models under various distribution assumptions.

  6. Imperfect pitchfork bifurcation in asymmetric two-compartment granular gas

    Institute of Scientific and Technical Information of China (English)

    Zhang Yin; Li Yin-Chang; Liu Rui; Cui Fei-Fei; Pierre Evesque; Hou Mei-Ying

    2013-01-01

    The clustering behavior of a mono-disperse granular gas is experimentally studied in an asymmetric two-compartment setup.Unlike the random clustering in either compartment in the case of symmetric configuration when lowering the shaking strength to below a critical value,the directed clustering is observed,which corresponds to an imperfect pitchfork bifurcation.Numerical solutions of the flux equation using a modified simple flux function show qualitative agreements with the experimental results.The potential application of this asymmetric structure is discussed.

  7. Controlled synthesis, asymmetrical transport behavior and luminescence properties of lanthanide doped ZnO mushroom-like 3D hierarchical structures.

    Science.gov (United States)

    Yue, Dan; Lu, Wei; Jin, Lin; Li, Chunyang; Luo, Wen; Wang, Mengnan; Wang, Zhenling; Hao, Jianhua

    2014-11-21

    Lanthanide doped ZnO mushroom-like 3D hierarchical structures have been fabricated by polyol-mediated method and characterized by various microstructural and optical techniques. The results indicate that the as-prepared ZnO:Ln(3+) (Ln = Tb, Eu) samples have a hexagonal phase structure and possess a mushroom-like 3D hierarchical morphology. The length of the whole mushroom from stipe bottom to pileus top is about 1.0 μm, and the diameters of pileus and stipe are about 0.8 μm and 0.4 μm, respectively. It is found that the flow of N2 is the key parameter for the formation of the novel ZnO structure and the addition of (NH4)2HPO4 has a prominent effect on the phase structure and the growth of mushroom-like morphology. The potential mechanism of forming this morphology is proposed. The pileus of the formed mushroom is assembled by several radial ZnO:Ln(3+) nanorods, whereas the stipe is composed of over layered ZnO:Ln(3+) nanosheets. Moreover, asymmetrical I-V characteristic curves of ZnO:Ln(3+) mushrooms indicate that the texture composition of the 3D hierarchical morphology might lead to the asymmetrical transport behavior of electrical conductivity. Lanthanide doped ZnO samples can exhibit red or green emission under the excitation of UV light.

  8. Extracellular matrix components direct porcine muscle stem cell behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, Karlijn J. [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands); Haagsman, Henk P. [Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht (Netherlands); Roelen, Bernard A.J., E-mail: b.a.j.roelen@uu.nl [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands)

    2010-02-01

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  9. Transcranial Direct Current Stimulation and behavioral models of smoking addiction

    Directory of Open Access Journals (Sweden)

    Paige eFraser

    2012-08-01

    Full Text Available While few studies have applied transcranial direct current stimulation (tDCS to smoking addiction, existing work suggests that the intervention holds promise for altering the complex system by which environmental cues interact with cravings to drive behavior. Imaging and repetitive transcranial magnetic stimulation (rTMS studies suggest that increased dorsolateral prefrontal cortex (DLPFC activation and integrity may be associated with increased resistance to smoking cues. Anodal tDCS of the DLPFC, believed to boost activation, reduces cravings in response to these cues. The finding that noninvasive stimulation modifies cue induced cravings has profound implications for understanding the processes underlying addiction and relapse. TDCS can also be applied to probe mechanisms underlying and supporting nicotine addiction, as was done in a pharmacologic study that applied nicotine, tDCS, and TMS paired associative stimulation to find that stopping nicotine after chronic use induces a reduction in plasticity, causing difficulty in breaking free from association between cues and cravings. This mini-review will place studies that apply tDCS to smokers in the context of research involving the neural substrates of nicotine addiction.

  10. Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts.

    Science.gov (United States)

    Wang, Kun; Zhou, Jianfeng; Hamill, Joseph M; Xu, Bingqian

    2014-08-01

    The contact effects of single-molecule break junctions on rectification behaviors were experimentally explored by a systematic control of anchoring groups of 1,4-disubstituted benzene molecular junctions. Single-molecule conductance and I-V characteristic measurements reveal a strong correlation between rectifying effects and the asymmetry in contacts. Analysis using energy band models and I-V calculations suggested that the rectification behavior is mainly caused by asymmetric coupling strengths at the two contact interfaces. Fitting of the rectification ratio by a modified Simmons model we developed suggests asymmetry in potential drop across the asymmetric anchoring groups as the mechanism of rectifying I-V behavior. This study provides direct experimental evidence and sheds light on the mechanisms of rectification behavior induced simply by contact asymmetry, which serves as an aid to interpret future single-molecule electronic behavior involved with asymmetric contact conformation.

  11. Transition behavior of asymmetric polystyrene-b-poly(2-vinylpyridine) films: A stable hexagonally modulated layer structure

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sungmin; Koo, Kyosung; Kim, Kyunginn; Ahn, Hyungju; Lee, Byeongdu; Park, Cheolmin; Ryu, Du Yeol

    2015-03-09

    The phase transitions in the films of an asymmetric polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) were investigated by grazing incidence small-angle X-ray scattering (GISAXS) and transmission electron microscopy (TEM). Compared with the sequential transitions in the bulk, hexagonally perforated layer (HPL) – gyroid (GYR) – disorder (DIS) upon heating, the transitions in film geometry were dramatically changed with decreasing thickness due to the growing preferential interactions from substrate, resulting in a thickness-dependent transition diagram including four different morphologies of hexagonally modulated layer (HML), coexisting (HML and GYR), GYR, and DIS. Particularly in the films ≤10Lo, where Lo is d-spacing at 150 °C, a stable HML structure was identified even above the order-to-disorder transition (ODT) temperature of the bulk, which was attributed to the suppressed compositional fluctuations by the enhanced substrate interactions.

  12. Customer engagement behavior : Theoretical foundations and research directions

    NARCIS (Netherlands)

    van Doorn, J.; Lemon, K.N.; Mittal, V.; Nass, S.; Pick, D.; Pirner, P.; Verhoef, P.C.

    2010-01-01

    This article develops and discusses the concept of customer engagement behaviors (CEB), which we define as the customers' behavioral manifestation toward a brand or firm, beyond purchase, resulting from motivational drivers. CEBs include a vast array of behaviors including word-of-mouth (WOM) activi

  13. Customer engagement behavior : Theoretical foundations and research directions

    NARCIS (Netherlands)

    van Doorn, J.; Lemon, K.N.; Mittal, V.; Nass, S.; Pick, D.; Pirner, P.; Verhoef, P.C.

    2010-01-01

    This article develops and discusses the concept of customer engagement behaviors (CEB), which we define as the customers' behavioral manifestation toward a brand or firm, beyond purchase, resulting from motivational drivers. CEBs include a vast array of behaviors including word-of-mouth (WOM) activi

  14. Customer engagement behavior : Theoretical foundations and research directions

    NARCIS (Netherlands)

    van Doorn, J.; Lemon, K.N.; Mittal, V.; Nass, S.; Pick, D.; Pirner, P.; Verhoef, P.C.

    This article develops and discusses the concept of customer engagement behaviors (CEB), which we define as the customers' behavioral manifestation toward a brand or firm, beyond purchase, resulting from motivational drivers. CEBs include a vast array of behaviors including word-of-mouth (WOM)

  15. The impact of behavior-specific and behavior-nonspecific reinforcement on child compliance to mother directives.

    Science.gov (United States)

    Strand, P S; Wahler, R G; Herring, M

    2001-09-01

    Theories of child socialization differ with regard to the influence they attribute to behavior-specific reinforcement contingencies versus behavior-nonspecific reinforcement contingencies (i.e. social responsiveness). The present research investigated, at a within-individual level, the relationship between both types of reinforcement and child compliance with maternal directives. Behavior-specific reinforcement was defined as the history of reinforcement obtained by children for prior episodes of compliance and noncompliance to mother directives. Behavior-nonspecific reinforcement was defined as the history of reinforcement obtained by children for prosocial and aversive behaviors unrelated to mother directives. It was hypothesized that both reinforcement processes would be related to child responses to subsequent mother directives. The findings support these hypotheses. The discussion addresses caretaker social responsiveness as an intervention target of behavioral family therapy.

  16. Direct catalytic asymmetric addition of allyl cyanide to ketones via soft Lewis acid/hard Brønsted base/hard Lewis base catalysis.

    Science.gov (United States)

    Yazaki, Ryo; Kumagai, Naoya; Shibasaki, Masakatsu

    2010-04-21

    We report that a hard Lewis base substantially affects the reaction efficiency of direct catalytic asymmetric gamma-addition of allyl cyanide (1a) to ketones promoted by a soft Lewis acid/hard Brønsted base catalyst. Mechanistic studies have revealed that Cu/(R,R)-Ph-BPE and Li(OC(6)H(4)-p-OMe) serve as a soft Lewis acid and a hard Brønsted base, respectively, allowing for deprotonative activation of 1a as the rate-determining step. A ternary catalytic system comprising a soft Lewis acid/hard Brønsted base and an additional hard Lewis base, in which the basicity of the hard Brønsted base Li(OC(6)H(4)-p-OMe) was enhanced by phosphine oxide (the hard Lewis base) through a hard-hard interaction, outperformed the previously developed binary soft Lewis acid/hard Brønsted base catalytic system, leading to higher yields and enantioselectivities while using one-tenth the catalyst loading and one-fifth the amount of 1a. This second-generation catalyst allows efficient access to highly enantioenriched tertiary alcohols under nearly ideal atom-economical conditions (0.5-1 mol % catalyst loading and a substrate molar ratio of 1:2).

  17. Complex colony-level organization of the deep-sea siphonophore Bargmannia elongata (Cnidaria, Hydrozoa) is directionally asymmetric and arises by the subdivision of pro-buds.

    Science.gov (United States)

    Dunn, Casey W

    2005-12-01

    Siphonophores are free-swimming colonial hydrozoans (Cnidaria) composed of asexually produced multicellular zooids. These zooids, which are homologous to solitary animals, are functionally specialized and arranged in complex species-specific patterns. The coloniality of siphonophores provides an opportunity to study the major transitions in evolution that give rise to new levels of biological organization, but siphonophores are poorly known because they are fragile and live in the open ocean. The organization and development of the deep-sea siphonophore Bargmannia elongata is described here using specimens collected with a remotely operated underwater vehicle. Each bud gives rise to a precise, directionally asymmetric sequence of zooids through a stereotypical series of subdivisions, rather than to a single zooid as in most other hydrozoans. This initial description of development in a deep-sea siphonophore provides an example of how precise colony-level organization can arise, and illustrates that the morphological complexity of cnidarians is greater than is often assumed. Copyright 2005 Wiley-Liss, Inc.

  18. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Directory of Open Access Journals (Sweden)

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  19. Fostering Sustainable Travel Behavior: Role of Sustainability Labels and Goal-Directed Behavior Regarding Touristic Services

    Directory of Open Access Journals (Sweden)

    Elfriede Penz

    2017-06-01

    Full Text Available Individuals around the globe engage in sustainable consumption in their everyday life, e.g., when it comes to individual transportation. Although tourism behavior contributes to global carbon emissions to a considerable extent, consumers’ awareness of sustainability in the tourism industry is still underresearched. Placing eco-labels next to tourist offers on websites might direct consumer’s perception towards more sustainable offers. By employing eye-tracking techniques and surveys, this research aimed at linking information about sustainable tourist offers, perception of eco-labels and subsequent perception and preferences of tourism services. In Study 1, eight existing hotel offers with sustainability certification (four different labels were selected and their websites presented to 48 participants (four websites each, whose eye movements were tracked. After looking at each website, they rated the overall appearance of the website. Based on the results, in the second study, participants’ (n = 642 awareness of labels, their values and attitudes regarding sustainable behavior were found to influence their preference for certified tour operators. In addition, individuals’ ideas of their perfect holidays were captured to allow a better understanding of their motivation. This research proposes implementing appropriate sustainable labeling in the tourism industry to increase awareness about sustainability among travelers and subsequently increase sustainable travel behavior.

  20. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    that oscillate in certain directions. Reflection or scattering of light favours certain orientations of the electric and magnetic fields over others. This is why polarising sunglasses can filter out the glint of sunlight reflected off a pond. When light scatters through the expanding debris of a supernova, it retains information about the orientation of the scattering layers. If the supernova is spherically symmetric, all orientations will be present equally and will average out, so there will be no net polarisation. If, however, the gas shell is not round, a slight net polarisation will be imprinted on the light. This is what broad-band polarimetry can accomplish. If additional spectral information is available ('spectro-polarimetry'), one can determine whether the asymmetry is in the continuum light or in some spectral lines. In the case of the Type Ia supernovae, the astronomers found that the continuum polarisation is very small so that the overall shape of the explosion is crudely spherical. But the much larger polarization in strongly blue-shifted spectral lines evidences the presence, in the outer regions, of fast moving clumps with peculiar chemical composition. "Our study reveals that explosions of Type Ia supernovae are really three-dimensional phenomena," says Dietrich Baade. "The outer regions of the blast cloud is asymmetric, with different materials found in 'clumps', while the inner regions are smooth." "This study was possible because polarimetry could unfold its full strength thanks to the light-collecting power of the Very Large Telescope and the very precise calibration of the FORS instrument," he adds. The research team first spotted this asymmetry in 2003, as part of the same observational campaign (ESO PR 23/03 and ESO PR Photo 26/05). The new, more extensive results show that the degree of polarisation and, hence, the asphericity, correlates with the intrinsic brightness of the explosion. The brighter the supernova, the smoother, or less clumpy

  1. Providers' response to child eating behaviors: A direct observation study.

    Science.gov (United States)

    Tovar, Alison; Vaughn, Amber E; Fallon, Megan; Hennessy, Erin; Burney, Regan; Østbye, Truls; Ward, Dianne S

    2016-10-01

    Child care providers play an important role in feeding young children, yet little is known about children's influence on providers' feeding practices. This qualitative study examines provider and child (18 months -4 years) feeding interactions. Trained data collectors observed 200 eating occasions in 48 family child care homes and recorded providers' responses to children's meal and snack time behaviors. Child behaviors initiating provider feeding practices were identified and practices were coded according to higher order constructs identified in a recent feeding practices content map. Analysis examined the most common feeding practices providers used to respond to each child behavior. Providers were predominately female (100%), African-American (75%), and obese (77%) and a third of children were overweight/obese (33%). Commonly observed child behaviors were: verbal and non-verbal refusals, verbal and non-verbal acceptance, being "all done", attempts for praise/attention, and asking for seconds. Children's acceptance of food elicited more autonomy supportive practices vs. coercive controlling. Requests for seconds was the most common behavior, resulting in coercive controlling practices (e.g., insisting child eat certain food or clean plate). Future interventions should train providers on responding to children's behaviors and helping children become more aware of internal satiety and hunger cues.

  2. Direct Marketing: Theoretical delimitation and impact on consumer buying behavior

    OpenAIRE

    Carlos Gazquez-Abad, Juan; De Cannière, Marie Hélène

    2008-01-01

    Direct marketing has become one of the most important communication tools for marketers. Direct marketing activities' budget is even higher than that for traditional advertising mass media, such as TV. However, there is not a single definition. On the contrary, several definitions have emerged in the literature. In this work, we establish a theoretical delimitation for direct marketing concept from those different perspectives analysed in marketing literature. In addition, an empirical analys...

  3. Asymmetric coherent transmission for single particle diode and gyroscope

    OpenAIRE

    S. Yang; Song, Z; Sun, C.P.

    2009-01-01

    We study the single particle scattering process in a coherent multi-site system consisting of a tight-binding ring threaded by an Aharonov-Bohm flux and several attaching leads. The asymmetric behavior of scattering matrix is discovered analytically in the framework of both Bethe Ansatz and Green's function formalism. It is found that, under certain conditions, a three-site electronic system can behave analogous to a perfect semiconductor diode where current flows only in one direction. The g...

  4. Aggregation behavior of fullerenes in aqueous solutions: a capillary electrophoresis and asymmetric flow field-flow fractionation study

    NARCIS (Netherlands)

    A. Astefanei; O. Núñez; M.T. Galceran; W.Th. Kok; P.J. Schoenmakers

    2015-01-01

    In this work, the electrophoretic behavior of hydrophobic fullerenes [buckminsterfullerene (C-60), C-70, and N-methyl-fulleropyrrolidine (C-60-pyrr)] and water-soluble fullerenes [fullerol (C-60(OH)(24)); polyhydroxy small gap fullerene, hydrated (C-120(OH)(30)); C-60 pyrrolidine tris acid (C-60-pyr

  5. Aggregation behavior of fullerenes in aqueous solutions: a capillary electrophoresis and asymmetric flow field-flow fractionation study

    NARCIS (Netherlands)

    Astefanei, A.; Núñez, O.; Galceran, M.T.; Kok, W.Th.; Schoenmakers, P.J.

    2015-01-01

    In this work, the electrophoretic behavior of hydrophobic fullerenes [buckminsterfullerene (C-60), C-70, and N-methyl-fulleropyrrolidine (C-60-pyrr)] and water-soluble fullerenes [fullerol (C-60(OH)(24)); polyhydroxy small gap fullerene, hydrated (C-120(OH)(30)); C-60 pyrrolidine tris acid

  6. Shaping embodied neural networks for adaptive goal-directed behavior.

    Directory of Open Access Journals (Sweden)

    Zenas C Chao

    2008-03-01

    Full Text Available The acts of learning and memory are thought to emerge from the modifications of synaptic connections between neurons, as guided by sensory feedback during behavior. However, much is unknown about how such synaptic processes can sculpt and are sculpted by neuronal population dynamics and an interaction with the environment. Here, we embodied a simulated network, inspired by dissociated cortical neuronal cultures, with an artificial animal (an animat through a sensory-motor loop consisting of structured stimuli, detailed activity metrics incorporating spatial information, and an adaptive training algorithm that takes advantage of spike timing dependent plasticity. By using our design, we demonstrated that the network was capable of learning associations between multiple sensory inputs and motor outputs, and the animat was able to adapt to a new sensory mapping to restore its goal behavior: move toward and stay within a user-defined area. We further showed that successful learning required proper selections of stimuli to encode sensory inputs and a variety of training stimuli with adaptive selection contingent on the animat's behavior. We also found that an individual network had the flexibility to achieve different multi-task goals, and the same goal behavior could be exhibited with different sets of network synaptic strengths. While lacking the characteristic layered structure of in vivo cortical tissue, the biologically inspired simulated networks could tune their activity in behaviorally relevant manners, demonstrating that leaky integrate-and-fire neural networks have an innate ability to process information. This closed-loop hybrid system is a useful tool to study the network properties intermediating synaptic plasticity and behavioral adaptation. The training algorithm provides a stepping stone towards designing future control systems, whether with artificial neural networks or biological animats themselves.

  7. How Digital Scaffolds in Games Direct Problem-Solving Behaviors

    Science.gov (United States)

    Sun, Chuen-Tsai; Wang, Dai-Yi; Chan, Hui-Ling

    2011-01-01

    Digital systems offer computational power and instant feedback. Game designers are using these features to create scaffolding tools to reduce player frustration. However, researchers are finding some unexpected effects of scaffolding on strategy development and problem-solving behaviors. We used a digital Sudoku game named "Professor Sudoku" to…

  8. Behavioral health leadership: new directions in occupational mental health.

    Science.gov (United States)

    Adler, Amy B; Saboe, Kristin N; Anderson, James; Sipos, Maurice L; Thomas, Jeffrey L

    2014-10-01

    The impact of stress on mental health in high-risk occupations may be mitigated by organizational factors such as leadership. Studies have documented the impact of general leadership skills on employee performance and mental health. Other researchers have begun examining specific leadership domains that address relevant organizational outcomes, such as safety climate leadership. One emerging approach focuses on domain-specific leadership behaviors that may moderate the impact of combat deployment on mental health. In a recent study, US soldiers deployed to Afghanistan rated leaders on behaviors promoting management of combat operational stress. When soldiers rated their leaders high on these behaviors, soldiers also reported better mental health and feeling more comfortable with the idea of seeking mental health treatment. These associations held even after controlling for overall leadership ratings. Operational stress leader behaviors also moderated the relationship between combat exposure and soldier health. Domain-specific leadership offers an important step in identifying measures to moderate the impact of high-risk occupations on employee health.

  9. The Association of Birth Complications and Externalizing Behavior in Early Adolescents: Direct and Mediating Effects

    Science.gov (United States)

    Liu, Jianghong; Raine, Adrian; Wuerker, Anne; Venables, Peter H.; Mednick, Sarnoff

    2009-01-01

    Prior studies have shown that birth complications interact with psychosocial risk factors in predisposing to increased externalizing behavior in childhood and criminal behavior in adulthood. However, little is known about the direct relationship between birth complications and externalizing behavior. Furthermore, the mechanism by which the birth…

  10. A Human Motor Behavior Model for Direct Pointing at a Distance

    OpenAIRE

    Kopper, Regis; Bowman,Doug A.; Silva, Mara G.

    2008-01-01

    Models of human motor behavior are well known as an aid in the design of user interfaces (UIs). Most current models apply primarily to desktop interaction, but with the development of non-desktop UIs, new types of motor behaviors need to be modeled. Direct Pointing at a Distance is such a motor behavior. A model of direct pointing at a distance would be particularly useful in the comparison of different interaction techniques, because the performance of such techniques is highly dependent on ...

  11. The endocannabinoid system: directing eating behavior and macronutrient metabolism

    OpenAIRE

    Bruce Alan Watkins; Jeffrey eKim

    2015-01-01

    For many years, the brain has been the primary focus for research on eating behavior. More recently, the discovery of the endogenous endocannabinoids (EC) and the endocannabinoid system (ECS), as well as the characterization of its actions on appetite and metabolism, has provided greater insight on the brain and food intake. The purpose of this review is to explain the actions of EC in the brain and other organs as well as their precursor polyunsaturated fatty acids (PUFA) that are converte...

  12. The endocannabinoid system: directing eating behavior and macronutrient metabolism

    OpenAIRE

    Watkins, Bruce A.; Kim, Jeffrey

    2015-01-01

    For many years, the brain has been the primary focus for research on eating behavior. More recently, the discovery of the endocannabinoids (EC) and the endocannabinoid system (ECS), as well as the characterization of its actions on appetite and metabolism, has provided greater insight on the brain and food intake. The purpose of this review is to explain the actions of EC in the brain and other organs as well as their precursor polyunsaturated fatty acids (PUFA) that are converted to these en...

  13. Native mass spectrometry provides direct evidence for DNA mismatch-induced regulation of asymmetric nucleotide binding in mismatch repair protein MutS

    NARCIS (Netherlands)

    M.C. Monti; S.X. Cohen (Serge); A. Fish (Alexander); H.H.K. Winterwerp (Herrie); A. Barendregt (Arjan); P. Friedhoff (Peter); A. Perrakis (Anastassis); A.J.R. Heck (Albert); T.K. Sixma (Titia); R.H.H. van den Heuvel (Robert); J.H.G. Lebbink (Joyce)

    2011-01-01

    textabstractThe DNA mismatch repair protein MutS recognizes mispaired bases in DNA and initiates repair in an ATP-dependent manner. Understanding of the allosteric coupling between DNA mismatch recognition and two asymmetric nucleotide binding sites at opposing sides of the MutS dimer requires ident

  14. Direct Asymmetric Michael Additions of Ketones to Nitroolefins and Chalcones Catalyzed by a Chiral C2-Symmetric Pyrrolidine-based Tetraamine

    Institute of Scientific and Technical Information of China (English)

    马世俊; 吴璐璐; 刘明; 王永梅

    2012-01-01

    C2-Symmetric pyrrolidine-based tetraamine, available from commercially starting materials, showed good cata- lytic activity for asymmetric Michael additions of ketones to nitroalkenes especially to chalcones. The reactions proceeded to give the corresponding products in good yields and in a highly selective manner.

  15. Unpacking Links between Fathers' Antisocial Behaviors and Children's Behavior Problems: Direct, Indirect, and Interactive Effects

    Science.gov (United States)

    Coley, Rebekah Levine; Carrano, Jennifer; Lewin-Bizan, Selva

    2011-01-01

    Building upon previous evidence for the intergenerational transmission of antisocial behaviors, this research assessed and compared three models seeking to explain links between fathers' antisocial behaviors and children's behavior problems. A representative sample of children from low-income families (N = 261) was followed from age 3 through age…

  16. Asymmetric flow networks

    OpenAIRE

    Olaizola Ortega, María Norma; Valenciano Llovera, Federico

    2012-01-01

    This paper provides a new model of network formation that bridges the gap between the two benchmark models by Bala and Goyal, the one-way flow model, and the two-way flow model, and includes both as particular extreme cases. As in both benchmark models, in what we call an "asymmetric flow" network a link can be initiated unilaterally by any player with any other, and the flow through a link towards the player who supports it is perfect. Unlike those models, in the opposite direction there is ...

  17. Electromyographic analysis of goal-directed grasping behavior in the American lobster.

    Science.gov (United States)

    Tomina, Yusuke; Takahata, Masakazu

    2014-10-15

    Animals spontaneously initiate goal-directed behavior including foraging action based on their appetitive motivation. The American lobster Homarus americanus exhibits grasping behavior with its crusher claw as feeding behavior that can be initiated after appropriate operant conditioning. In order to quantitatively characterize the goal-directed grasping behavior with a time resolution fine enough for neurophysiological analysis of its initiation and control mechanisms, we made simultaneous electromyographic (EMG) recording from grasping- and reaching-related muscles of the crusher claw while animals initiated grasping behavior. We developed an in vivo extracellular recording chamber that allowed the animal under a semi-restrained condition to perform operant reward learning of claw grasping. Three muscles in the crusher claw (propodite-dactyl closer/opener and coxal protractor) were found to be closely associated with spontaneous grasping behavior. In spontaneous grasping, the activation of those muscles consistently preceded the grasping onset time and exhibited different activity patterns from the grasp induced by a mechanical stimulus. Furthermore, we found that the timing of coxal protractor activation was closer to the grasp onset and its activity was briefer for goal-directed grasping behavior in trained and hungry animals than for non-goal-directed spontaneous grasping behavior in naive or satiated animals. It is suggested that the goal-directed grasping behavior of lobster is characterized, at least partly, by experience-dependent briefer activity of specific muscles involved in reaching action.

  18. Directions in implementation research methods for behavioral and social science.

    Science.gov (United States)

    Irwin, Molly; Supplee, Lauren H

    2012-10-01

    There is a growing interest, by researchers, policymakers, and practitioners, in evidence-based policy and practice. As a result, more dollars are being invested in program evaluation in order to establish "what works," and in some cases, funding is specifically tied to those programs found to be effective. However, reproducing positive effects found in research requires more than simply adopting an evidence-based program. Implementation research can provide guidance on which components of an intervention matter most for program impacts and how implementation components can best be implemented. However, while the body of rigorous research on effective practices continues to grow, research on implementation lags behind. To address these issues, the Administration for Children and Families and federal partners convened a roundtable meeting entitled, Improving Implementation Research Methods for Behavioral and Social Science, in the fall of 2010. This special section of the Journal of Behavioral Health Services & Research includes papers from the roundtable and highlights the role implementation science can play in shedding light on the difficult task of taking evidence-based practices to scale.

  19. Citizen science: a new direction in canine behavior research.

    Science.gov (United States)

    Hecht, Julie; Spicer Rice, Eleanor

    2015-01-01

    Researchers increasingly rely on members of the public to contribute to scientific projects-from collecting or identifying, to analyzing and disseminating data. The "citizen science" model proves useful to many thematically distinctive fields, like ornithology, astronomy, and phenology. The recent formalization of citizen science projects addresses technical issues related to volunteer participation--like data quality--so that citizen scientists can make longstanding, meaningful contributions to scientific projects. Since the late 1990s, canine science research has relied with greater frequency on the participation of the general public, particularly dog owners. These researchers do not typically consider the methods and technical issues that those conducting citizen science projects embrace and continue to investigate. As more canine science studies rely on public input, an in-depth knowledge of the benefits and challenges of citizen science can help produce relevant, high-quality data while increasing the general public's understanding of canine behavior and cognition as well as the scientific process. We examine the benefits and challenges of current citizen science models in an effort to enhance canine citizen science project preparation, execution, and dissemination. This article is part of a Special Issue entitled: Canine Behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. The endocannabinoid system: directing eating behavior and macronutrient metabolism

    Directory of Open Access Journals (Sweden)

    Bruce Alan Watkins

    2015-01-01

    Full Text Available For many years, the brain has been the primary focus for research on eating behavior. More recently, the discovery of the endogenous endocannabinoids (EC and the endocannabinoid system (ECS, as well as the characterization of its actions on appetite and metabolism, has provided greater insight on the brain and food intake. The purpose of this review is to explain the actions of EC in the brain and other organs as well as their precursor polyunsaturated fatty acids (PUFA that are converted to these endogenous ligands. The binding of the EC to the cannabinoid receptors in the brain stimulates food intake, and the ECS participates in systemic macronutrient metabolism where the gastrointestinal system, liver, muscle, and adipose are involved. The EC are biosynthesized from two distinct families of dietary PUFA, namely the n-6 and n-3. Based on their biochemistry, these PUFA are well known to exert considerable physiological and health-promoting actions. However, little is known about how these different families of PUFA compete as precursor ligands of cannabinoid receptors to stimulate appetite or perhaps down-regulate the ECS to amend food intake and prevent or control obesity. The goal of this review is to assess the current available research on ECS and food intake, suggest research that may improve the complications associated with obesity and diabetes by dietary PUFA intervention, and further reveal mechanisms to elucidate the relationships between substrate for EC synthesis, ligand actions on receptors, and the physiological consequences of the ECS. Dietary PUFA are lifestyle factors that could potentially curb eating behavior, which may translate to changes in macronutrient metabolism, systemically and in muscle, benefiting health overall.

  1. The endocannabinoid system: directing eating behavior and macronutrient metabolism.

    Science.gov (United States)

    Watkins, Bruce A; Kim, Jeffrey

    2014-01-01

    For many years, the brain has been the primary focus for research on eating behavior. More recently, the discovery of the endocannabinoids (EC) and the endocannabinoid system (ECS), as well as the characterization of its actions on appetite and metabolism, has provided greater insight on the brain and food intake. The purpose of this review is to explain the actions of EC in the brain and other organs as well as their precursor polyunsaturated fatty acids (PUFA) that are converted to these endogenous ligands. The binding of the EC to the cannabinoid receptors in the brain stimulates food intake, and the ECS participates in systemic macronutrient metabolism where the gastrointestinal system, liver, muscle, and adipose are involved. The EC are biosynthesized from two distinct families of dietary PUFA, namely the n-6 and n-3. Based on their biochemistry, these PUFA are well known to exert considerable physiological and health-promoting actions. However, little is known about how these different families of PUFA compete as precursor ligands of cannabinoid receptors to stimulate appetite or perhaps down-regulate the ECS to amend food intake and prevent or control obesity. The goal of this review is to assess the current available research on ECS and food intake, suggest research that may improve the complications associated with obesity and diabetes by dietary PUFA intervention, and further reveal mechanisms to elucidate the relationships between substrate for EC synthesis, ligand actions on receptors, and the physiological consequences of the ECS. Dietary PUFA are lifestyle factors that could potentially curb eating behavior, which may translate to changes in macronutrient metabolism, systemically and in muscle, benefiting health overall.

  2. Asymmetric transmission of acoustic waves in a layer thickness distribution gradient structure using metamaterials

    Science.gov (United States)

    Chen, Jung-San; Chang, I.-Ling; Huang, Wan-Ting; Chen, Lien-Wen; Huang, Guan-Hua

    2016-09-01

    This research presents an innovative asymmetric transmission design using alternate layers of water and metamaterial with complex mass density. The directional transmission behavior of acoustic waves is observed numerically inside the composite structure with gradient layer thickness distribution and the rectifying performance of the present design is evaluated. The layer thickness distributions with arithmetic and geometric gradients are considered and the effect of gradient thickness on asymmetric wave propagation is systematically investigated using finite element simulation. The numerical results indicate that the maximum pressure density and transmission through the proposed structure are significantly influenced by the wave propagation direction over a wide range of audible frequencies. Tailoring the thickness of the layered structure enables the manipulation of asymmetric wave propagation within the desired frequency range. In conclusion, the proposed design offers a new possibility for developing directional-dependent acoustic devices.

  3. Direct and contextual effects of individual values on organizational citizenship behavior in teams.

    Science.gov (United States)

    Arthaud-Day, Marne L; Rode, Joseph C; Turnley, William H

    2012-07-01

    The authors use Schwartz's values theory as an integrative framework for testing the relationship between individual values and peer-reported organizational citizenship behavior (OCB) in teams, controlling for sex, satisfaction, and personality traits. Using hierarchical linear modeling in a sample of 582 students distributed across 135 class project teams, the authors find positive, direct effects for achievement on citizenship behaviors directed toward individuals (OCB-I), for benevolence on citizenship behaviors directed toward the group (OCB-O), and for self-direction on both OCB-I and OCB-O. Applying relational demography techniques to test for contextual effects, the authors find that group mean power scores negatively moderate the relationship between individual power and OCB-I, whereas group mean self-direction scores positively moderate the relationship between self-direction and both OCB-I and OCB-O.

  4. Rewards and punishments, goal-directed behavior and consciousness.

    Science.gov (United States)

    Ressler, Newton

    2004-03-01

    A parsimonious account of consciousness is given in which it emerges as a direct consequence of basic neural processes without the necessity of any higher order system. In this model, pleasant or unpleasant conscious feelings of various stimuli in the environment stem from their higher order associations to innate rewards or punishments. When a conditioned stimulus (CS) is associated with a reward, it acquires pleasant feelings due to the temporal correlation of the activations representing its sensory features with those representing innate visceral reward acquisition processes. When the CS is associated with the punishment, it acquires unpleasant feelings due to the correlation of its sensory features with the innate visceral inhibition of punishment acquisition processes. The correlations involve coherent activity between the sensory cortex, the limbic system, the orbital and medial prefrontal cortex, and more lateral prefrontal areas where stimuli can be incorporated into working memory. A conscious act involves responses (or attempts to improve the environment) made on the basis of the feelings of such stimuli. Covert memory scans, in which comparisons are made of the reward and punishment associations of the outcomes of previous responses, are related to the motivations and attention behind the conscious selection of a current response. This model appears to fit together various empirical observations. Its relations to some higher or more abstract mental processes, and some evolutionary implications are discussed.

  5. Indirect and direct perceived behavioral control and the role of intention in the context of birth control behavior.

    Science.gov (United States)

    Hanson, Jessica D; Nothwehr, Faryle; Yang, Jingzhen Ginger; Romitti, Paul

    2015-07-01

    Unintended pregnancies can have negative consequences for both mother and child. The focus of this study was to utilize perceived behavioral control measures (PBC; part of the theory of planned behavior) to identify relevant behavioral determinants of birth control use. This study also tested associations between direct and indirect PBC measures and intention of birth control use and between intention and birth control use. The methods included a randomly selected sample of patients at a health care system in the Upper Midwest who were sent a self-administered survey, with 190 non-pregnant women returning completed surveys. Participants indicated a high level of control over using birth control, and a significant positive correlation was observed between direct and indirect PBC measures. Participants also reported high intentions to use birth control, and a significant positive correlation was observed between intention and PBC. Additionally, both PBC measures and intention were independently and significantly associated with behavior, and PBC remained significantly associated with behavior when intention was added into the model. In conclusion, compared to the previous literature, this study is unique in that it examines indirect PBC measures and also the important role that PBC plays with actual birth control behavior.

  6. Generalizability and Dependability of a Multi-Item Direct Behavior Rating Scale in a Kindergarten Classroom Setting

    Science.gov (United States)

    Wickerd, Garry; Hulac, David

    2017-01-01

    Accurate and rapid identification of students displaying behavioral problems requires instrumentation that is user friendly and reliable. The purpose of the study was to evaluate a multi-item direct behavior rating scale called the Direct Behavior Rating-Multiple Item Scale (DBR-MIS) for disruptive behavior to determine the number of…

  7. Health Behavior Theory and cumulative knowledge regarding health behaviors: are we moving in the right direction?

    Science.gov (United States)

    Noar, Seth M; Zimmerman, Rick S

    2005-06-01

    Although research on Health Behavior Theory (HBT) is being conducted at a rapid pace, the extent to which the field is truly moving forward in understanding health behavior has been questioned. This issue is examined in the current article. First, we discuss the problems within the HBT literature. Second, we discuss the proliferation of HBT and why theory comparison is essential to this area of research. Finally, we reflect on ways that the field might move forward by suggesting a new agenda for HBT research. It is argued that increased recognition of the similarity of health behavior constructs as well as increased empirical comparisons of theories are essential for true scientific progress in this line of inquiry.

  8. The neuropeptide PDF acts directly on evening pacemaker neurons to regulate multiple features of circadian behavior.

    Science.gov (United States)

    Lear, Bridget C; Zhang, Luoying; Allada, Ravi

    2009-07-01

    Discrete clusters of circadian clock neurons temporally organize daily behaviors such as sleep and wake. In Drosophila, a network of just 150 neurons drives two peaks of timed activity in the morning and evening. A subset of these neurons expresses the neuropeptide pigment dispersing factor (PDF), which is important for promoting morning behavior as well as maintaining robust free-running rhythmicity in constant conditions. Yet, how PDF acts on downstream circuits to mediate rhythmic behavior is unknown. Using circuit-directed rescue of PDF receptor mutants, we show that PDF targeting of just approximately 30 non-PDF evening circadian neurons is sufficient to drive morning behavior. This function is not accompanied by large changes in core molecular oscillators in light-dark, indicating that PDF RECEPTOR likely regulates the output of these cells under these conditions. We find that PDF also acts on this focused set of non-PDF neurons to regulate both evening activity phase and period length, consistent with modest resetting effects on core oscillators. PDF likely acts on more distributed pacemaker neuron targets, including the PDF neurons themselves, to regulate rhythmic strength. Here we reveal defining features of the circuit-diagram for PDF peptide function in circadian behavior, revealing the direct neuronal targets of PDF as well as its behavioral functions at those sites. These studies define a key direct output circuit sufficient for multiple PDF dependent behaviors.

  9. The Effects of Safety Behavior Directed Towards a Safety Cue on Perceptions of Threat.

    Science.gov (United States)

    Engelhard, Iris M; van Uijen, Sophie L; van Seters, Niels; Velu, Nicolette

    2015-09-01

    Safety behavior involves precautions to prevent or minimize a feared outcome, and is involved in the maintenance of anxiety disorders. Earlier research has shown that safety behavior prevents the extinction of conditioned fear and maintains threat expectations. This study tested whether safety behavior directed towards an objectively safe stimulus increases the perceived threat of that stimulus when it is subsequently experienced in the absence of the safety measure. In a conditioning task, participants first learned that one "danger" cue (A) was followed by shock and two "safety" cues (B, C) were not. Then they learned to apply safety behavior during A trials, which prevented the shock. Next, the experimental group, and not the control group, was given the opportunity to display safety behavior to C trials, which had never been coupled with the shock. In a subsequent test phase, A, B, and C were presented without the opportunity for participants to engage in safety behavior. Results showed that safety behavior increased shock expectancy to C in the test phase and maintained a preexisting shock expectancy in the experimental group, but not in the control group. This is the first study to show that safety behavior can maintain threat appraisal to stimuli that only ever acquired threat indirectly. This may be a possible mechanism for the origin of biased threat beliefs, superstitious behaviors, and irrational fears. It is also practically relevant: safety behavior reduces actual danger, but in relatively safe situations, its potential costs may outweigh the benefits. Copyright © 2015. Published by Elsevier Ltd.

  10. Asymmetric transition disks: Vorticity or eccentricity?

    CERN Document Server

    Zsom, A; Ghanbari, J

    2013-01-01

    Context. Transition disks typically appear in resolved millimeter observations as giant dust rings surrounding their young host stars. More accurate observations with ALMA have shown several of these rings to be in fact asymmetric: they have lopsided shapes. It has been speculated that these rings act as dust traps, which would make them important laboratories for studying planet formation. It has been shown that an elongated giant vortex produced in a disk with a strong viscosity jump strikingly resembles the observed asymmetric rings. Aims. We aim to study a similar behavior for a disk in which a giant planet is embedded. However, a giant planet can induce two kinds of asymmetries: (1) a giant vortex, and (2) an eccentric disk. We studied under which conditions each of these can appear, and how one can observationally distinguish between them. This is important because only a vortex can trap particles both radially and azimuthally, while the eccentric ring can only trap particles in radial direction. Method...

  11. Structural and dielectric behavior of pulsed laser ablated Sr 0.6Ca 0.4TiO 3 thin film and asymmetric multilayer of SrTiO 3 and CaTiO 3

    Science.gov (United States)

    Chakraborty, Pradip; Choudhury, Palash Roy; Krupanidhi, S. B.

    2011-12-01

    Homogeneous thin films of Sr 0.6Ca 0.4TiO 3 (SCT40) and asymmetric multilayer of SrTiO 3 (STO) and CaTiO 3 (CTO) were fabricated on Pt/Ti/SiO 2/Si substrates by using pulsed laser deposition technique. The electrical behavior of films was observed within a temperature range of 153 K-373 K. A feeble dielectric peak of SCT40 thin film at 273 K is justified as paraelectric to antiferroelectric phase transition. Moreover, the Curie-Weiss temperature, determined from the ɛ'( T) data above the transition temperature is found to be negative. Using Landau theory, the negative Curie-Weiss temperature is interpreted in terms of an antiferroelectric transition. The asymmetric multilayer exhibits a broad dielectric peak at 273 K, and is attributed to interdiffusion at several interfaces of multilayer. The average dielectric constants for homogeneous Sr 0.6Ca 0.4TiO 3 films (˜650) and asymmetric multilayered films (˜350) at room temperature are recognized as a consequence of grain size effect. Small frequency dispersion in the real part of the dielectric constants and relatively low dielectric losses for both cases ensure high quality of the films applicable for next generation integrated devices.

  12. Direct Behavior Rating: an evaluation of time-series interpretations as consequential validity.

    Science.gov (United States)

    Christ, Theodore J; Nelson, Peter M; Van Norman, Ethan R; Chafouleas, Sandra M; Riley-Tillman, T Chris

    2014-06-01

    Direct Behavior Rating (DBR) is a repeatable and efficient method of behavior assessment that is used to document teacher perceptions of student behavior in the classroom. Time-series data can be graphically plotted and visually analyzed to evaluate patterns of behavior or intervention effects. This study evaluated the decision accuracy of novice raters who were presented with single-phase graphical plots of DBR data. Three behaviors (i.e., academically engaged, disruptive, and respectful) and three graphical trends (i.e., positive, no trend, and negative) were analyzed by 27 graduate and five undergraduate participants who had minimal visual analysis experience. All graphs were unique, with data points arranged to form one of three "true" trends. Raters correctly classified graphs with positive, no, and negative trends an average of 76, 98, and 67% of instances. The generalized linear mixed model was used to handle significance tests for the categorical data. Results indicate that accuracy was influenced by the trend direction, with the most accurate ratings in the no trend condition. Despite the significant effect for trend direction, the current study provides empirical evidence for accuracy of DBR trends and interpretations. Novice raters and visual analysts yielded accurate decisions regarding the trend of plotted data for student behavior.

  13. Directionality Between Tolerance of Deviance and Deviant Behavior is Age-Moderated in Chronically Stressed Youth.

    Science.gov (United States)

    Ridenour, Ty A; Caldwell, Linda L; Coatsworth, J Douglas; Gold, Melanie A

    2011-03-20

    Problem behavior theory posits that tolerance of deviance is an antecedent to antisocial behavior and substance use. In contrast, cognitive dissonance theory implies that acceptability of a behavior may increase after experiencing the behavior. Using structural equation modeling, this investigation tested whether changes in tolerance of deviance precede changes in conduct disorder criteria or substance use or vice versa, or if they change concomitantly. Two-year longitudinal data from 246 8- to 16-year-olds suggested that tolerance of deviance increases after conduct disorder criteria or substance use in 8-to-10- and 11-to-12-year-olds. These results were consistent with cognitive dissonance theory. In 13-to-16- year-olds, no directionality was suggested, consistent with neither theory. These results were replicated in boys and girls and for different types of conduct disorder criteria aggression (covert behavior), deceitfulness and vandalism (overt behavior), and serious rule-breaking (authority conflict). The age-specific directionality between tolerance of deviance and conduct disorder criteria or substance use is consistent with unique etiologies between early onset versus adolescent-onset subtypes of behavior problems.

  14. Estimating direction in brain-behavior interactions: Proactive and reactive brain states in driving.

    Science.gov (United States)

    Garcia, Javier O; Brooks, Justin; Kerick, Scott; Johnson, Tony; Mullen, Tim R; Vettel, Jean M

    2017-02-22

    Conventional neuroimaging analyses have ascribed function to particular brain regions, exploiting the power of the subtraction technique in fMRI and event-related potential analyses in EEG. Moving beyond this convention, many researchers have begun exploring network-based neurodynamics and coordination between brain regions as a function of behavioral parameters or environmental statistics; however, most approaches average evoked activity across the experimental session to study task-dependent networks. Here, we examined on-going oscillatory activity as measured with EEG and use a methodology to estimate directionality in brain-behavior interactions. After source reconstruction, activity within specific frequency bands (delta: 2-3Hz; theta: 4-7Hz; alpha: 8-12Hz; beta: 13-25Hz) in a priori regions of interest was linked to continuous behavioral measurements, and we used a predictive filtering scheme to estimate the asymmetry between brain-to-behavior and behavior-to-brain prediction using a variant of Granger causality. We applied this approach to a simulated driving task and examined directed relationships between brain activity and continuous driving performance (steering behavior or vehicle heading error). Our results indicated that two neuro-behavioral states may be explored with this methodology: a Proactive brain state that actively plans the response to the sensory information and is characterized by delta-beta activity, and a Reactive brain state that processes incoming information and reacts to environmental statistics primarily within the alpha band.

  15. NCS-1 dependent learning bonus and behavior outputs of self-directed exploration

    Science.gov (United States)

    Mun, Ho-Suk

    Animals explore a new environment and learn about their surroundings. "Exploration" refers to all activities that increase the information obtained from an animal. For this study, I determined a molecule that mediates self-directed exploration, with a particular focus on rearing behavior and vocalization. Rearing can be either self-directed exploration or escape-oriented exploration. Self-directed exploration can be driven by the desire to gather information about environments while escape-oriented exploration can be driven by fear or anxiety. To differentiate between these two concepts, I compared rearing and other behaviors in three different conditions 1) novel dim (safe environment), which induces exploration based rearing; 2) novel bright (fearful environment), which elicits fear driven rearing; and 3) familiar environment as a control. First, I characterized the effects on two distinct types of environment in exploratory behavior and its effect on learning. From this, I determined that self-directed exploration enhances spatial learning while escape-oriented exploration does not produce a learning bonus. Second, I found that NCS-1 is involved in exploration, as well as learning and memory, by testing mice with reduced levels of Ncs-1 by point mutation and also siRNA injection. Finally, I illustrated other behavior outputs and neural substrate activities, which co-occurred during either self-directed or escape-oriented exploration. I found that high-frequency ultrasonic vocalizations occurred during self-directed exploration while low-frequency calls were emitted during escape-oriented exploration. Also, with immediate early gene imaging techniques, I found hippocampus and nucleus accumbens activation in self-directed exploration. This study is the first comprehensive molecular analysis of learning bonus in self-directed exploration. These results may be beneficial for studying underlying mechanisms of neuropsychiatric disease, and also reveal therapeutic

  16. Terahertz metamaterial with asymmetric transmission

    CERN Document Server

    Singh, R; Menzel, C; Rockstuhl, C; Azad, A K; Cheville, R A; Lederer, F; Zhang, W; Zheludev, N I

    2009-01-01

    We show for the first time that a planar metamaterial, an array of coupled metal split-ring resonators with a unit cell lacking mirror symmetry, exhibits asymmetric transmission of terahertz radiation propagating through it in opposite directions. This intriguing effect, that is compatible with Lorentz reciprocity and time-reversal, depends on a directional difference in conversion efficiency of the incident circularly polarized wave into one of opposite handedness, that is only possible in lossy low-symmetry planar chiral metamaterials. We show that asymmetric transmission is linked to excitation of enantiomerically sensitive plasmons, these are induced charge-field excitations that depend on the mutual handedness of incident wave and metamaterial pattern. Various bands of positive, negative and zero phase and group velocities have been identified indicating the opportunity to develop polarization sensitive negative index and slow light media based on such metamaterials.

  17. Effects of Strand Lay Direction and Crossing Angle on Tribological Behavior of Winding Hoist Rope

    Directory of Open Access Journals (Sweden)

    Xiang-dong Chang

    2017-06-01

    Full Text Available Friction and wear behavior exists between hoisting ropes that are wound around the drums of a multi-layer winding hoist. It decreases the service life of ropes and threatens mine safety. In this research, a series of experiments were conducted using a self-made test rig to study the effects of the strand lay direction and crossing angle on the winding rope’s tribological behavior. Results show that the friction coefficient in the steady-state period shows a decreasing tendency with an increase of the crossing angle in both cross directions, but the variation range is different under different cross directions. Using thermal imaging, the high temperature regions always distribute along the strand lay direction in the gap between adjacent strands, as the cross direction is the same with the strand lay direction (right cross contact. Additionally, the temperature rise in the steady-state increases with the increase of the crossing angle in both cross directions. The differences of the wear scar morphology are obvious under different cross directions, especially for the large crossing angle tests. In the case of right cross, the variation range of wear mass loss is larger than that in left cross. The damage that forms on the wear surface is mainly ploughing, pits, plastic deformation, and fatigue fracture. The major wear mechanisms are adhesive wear, and abrasive and fatigue wear.

  18. Effects of Strand Lay Direction and Crossing Angle on Tribological Behavior of Winding Hoist Rope.

    Science.gov (United States)

    Chang, Xiang-Dong; Peng, Yu-Xing; Zhu, Zhen-Cai; Gong, Xian-Sheng; Yu, Zhang-Fa; Mi, Zhen-Tao; Xu, Chun-Ming

    2017-06-09

    Friction and wear behavior exists between hoisting ropes that are wound around the drums of a multi-layer winding hoist. It decreases the service life of ropes and threatens mine safety. In this research, a series of experiments were conducted using a self-made test rig to study the effects of the strand lay direction and crossing angle on the winding rope's tribological behavior. Results show that the friction coefficient in the steady-state period shows a decreasing tendency with an increase of the crossing angle in both cross directions, but the variation range is different under different cross directions. Using thermal imaging, the high temperature regions always distribute along the strand lay direction in the gap between adjacent strands, as the cross direction is the same with the strand lay direction (right cross contact). Additionally, the temperature rise in the steady-state increases with the increase of the crossing angle in both cross directions. The differences of the wear scar morphology are obvious under different cross directions, especially for the large crossing angle tests. In the case of right cross, the variation range of wear mass loss is larger than that in left cross. The damage that forms on the wear surface is mainly ploughing, pits, plastic deformation, and fatigue fracture. The major wear mechanisms are adhesive wear, and abrasive and fatigue wear.

  19. "It does affect me” Disruptive behaviors in preadolescents directly and indirectly abused at home

    NARCIS (Netherlands)

    Baldry, A.C.

    2007-01-01

    Aggressive and delinquent behaviors in preadolescents may be indicators of problems suffered at home from direct child abuse by one or both parents or indirect abuse, such as exposure to domestic violence. A total of 532 Italian preadolescents recruited in their schools took part in this study. They

  20. Using a Combined Approach of Guided Inquiry & Direct Instruction to Explore How Physiology Affects Behavior

    Science.gov (United States)

    Machtinger, Erika T.

    2014-01-01

    Hands-on activities with live organisms allow students to actively explore scientific investigation. Here, I present activities that combine guided inquiry with direct instruction and relate how nutrition affects the physiology and behavior of the common housefly. These experiments encourage student involvement in the formulation of experimental…

  1. Training Blind Children to Employ Appropriate Gaze Direction and Sitting Behavior during Conversation.

    Science.gov (United States)

    Raver, Sharon A.

    1987-01-01

    Five congenitally blind children (ages 5-8) were trained to simultaneously employ appropriate gaze direction and sitting behavior while conversing with an adult. Training consisted of discussion, modeling, physical prompting, feedback, and positive reinforcement. All children reached criterion in 19 to 25 training sessions. (Author/DB)

  2. Internally generated sequences in learning and executing goal-directed behavior

    NARCIS (Netherlands)

    Pezzulo, G.; van der Meer, M.A.A.; Lansink, C.S.; Pennartz, C.M.A.

    2014-01-01

    A network of brain structures including hippocampus (HC), prefrontal cortex, and striatum controls goal-directed behavior and decision making. However, the neural mechanisms underlying these functions are unknown. Here, we review the role of 'internally generated sequences': structured, multi-neuron

  3. A Quasi-Linear Behavioral Model and an Application to Self-Directed Learning

    Science.gov (United States)

    Ponton, Michael K.; Carr, Paul B.

    1999-01-01

    A model is presented that describes the relationship between one's knowledge of the world and the concomitant personal behaviors that serve as a mechanism to obtain desired outcomes. Integrated within this model are the differing roles that outcomes serve as motivators and as modifiers to one's worldview. The model is dichotomized between general and contextual applications. Because learner self-directedness (a personal characteristic) involves cognition and affection while self-directed learning (a pedagogic process) encompasses conation, behavior and introspection, the model can be dichotomized again in another direction. Presented also are the roles that cognitive motivation theories play in moving an individual through this behavioral model and the roles of wishes, self-efficacy, opportunity and self-influence.

  4. A preliminary investigation of opinions and behaviors regarding advance directives for medical care.

    Science.gov (United States)

    Elpern, E H; Yellen, S B; Burton, L A

    1993-03-01

    Advance directives are a means of promoting patient autonomy in end-of-life decisions but are used infrequently. A recent federal law requires healthcare organizations to provide information to patients about advance directives. This study explored attitudes and behaviors related to the use of advance directives in three areas: familiarity with advance directives, reasons for completing or not completing advance directives and preferences for receiving information about advance directives. A questionnaire was administered by personal interview to a nonrandomized convenience sample of 46 inpatients and 50 outpatients at a large, tertiary care, urban academic medical center in the summer of 1991. Most respondents (77%) had heard of either the living will or durable power of attorney for healthcare, but only 52% correctly understood the purpose of these documents. Twenty-nine percent of the sample had executed an advance directive. Those who had advance directives were older and considered themselves less healthy than did those without advance directives. Unfamiliarity with advance directives and procrastination were cited most often as reasons for not having an advance directive. Most subjects (65%) had spoken with someone, usually a family member or close friend, about preferences for treatment during a critical illness. Although they had rarely discussed advance directives, 83% anticipated that they would be comfortable doing so with a physician or a nurse. Advance directives are used infrequently to document treatment preferences. The success of programs to promote greater use of advance directives depends on a clearer understanding of the factors that influence both decision and action to execute an advance directive. Patients claim to be comfortable in discussing the topic and prefer that such discussions occur in the outpatient setting.

  5. On the electron dynamics during island coalescence in asymmetric magnetic reconnection

    CERN Document Server

    Cazzola, Emanuele; Markidis, Stefano; Goldman, Martin V; Newman, David L; Lapenta, Giovanni

    2015-01-01

    We present an analysis of the electron dynamics during rapid island merging in asymmetric magnetic reconnection. We consider a doubly periodic system with two asymmetric transitions. The upper layer is an asymmetric Harris sheet initially perturbed to promote a single reconnection site. The lower layer is a tangential discontinuity that promotes the formation of many X-points, separated by rapidly merging islands. Across both layers the magnetic field and the density have a strong jump, but the pressure is held constant. Our analysis focuses on the consequences of electron energization during island coalescence. We focus first on the parallel and perpendicular components of the electron temperature to establish the presence of possible anisotropies and non-gyrotropies. Thanks to the direct comparison between the two different layers simulated, we can distinguish three main types of behavior characteristic of three different regions of interest. The first type represents the regions where traditional asymmetri...

  6. Participants' Assessment of the Impact of Behavioral Health Self-Direction on Recovery.

    Science.gov (United States)

    Croft, Bevin; Parish, Susan

    2016-10-01

    Self-direction involves managing a flexible budget, selecting and purchasing services and supports to meet individual needs and preferences. An emerging practice in the behavioral health field, self-direction is part of a systemic shift toward person-centered approaches to service provision. To understand the relationship between recovery and self-direction, the authors conducted a content analysis of 30 in-depth interviews with individuals from two self-direction programs in one state. A positive relationship between self-direction and recovery was established. Meeting basic needs for food, clothing, and shelter are important first steps in the recovery process for self-directing participants. Recovery domains were dynamic and interrelated, with gains in independence, self-esteem, and self-confidence facilitating achievement of goals in other domains. To maximize the benefits of self-direction, program administrators may need to develop clearer program implementation standards and address poverty and limited access to appropriate behavioral health services and supports.

  7. Devaluation and sequential decisions: linking goal-directed and model-based behavior.

    Science.gov (United States)

    Friedel, Eva; Koch, Stefan P; Wendt, Jean; Heinz, Andreas; Deserno, Lorenz; Schlagenhauf, Florian

    2014-01-01

    In experimental psychology different experiments have been developed to assess goal-directed as compared to habitual control over instrumental decisions. Similar to animal studies selective devaluation procedures have been used. More recently sequential decision-making tasks have been designed to assess the degree of goal-directed vs. habitual choice behavior in terms of an influential computational theory of model-based compared to model-free behavioral control. As recently suggested, different measurements are thought to reflect the same construct. Yet, there has been no attempt to directly assess the construct validity of these different measurements. In the present study, we used a devaluation paradigm and a sequential decision-making task to address this question of construct validity in a sample of 18 healthy male human participants. Correlational analysis revealed a positive association between model-based choices during sequential decisions and goal-directed behavior after devaluation suggesting a single framework underlying both operationalizations and speaking in favor of construct validity of both measurement approaches. Up to now, this has been merely assumed but never been directly tested in humans.

  8. Behavior of composite rigid frame bridge under bi-directional seismic excitations

    Directory of Open Access Journals (Sweden)

    Xiaogang Liu

    2014-02-01

    Full Text Available Pushover analysis and time history analysis are conducted to explore the bi-directional seismic behavior of composite steel-concrete rigid frame bridge, which is composed of RC piers and steel-concrete composite girders. Both longitudinal and transverse directions excitations are investigated using OpenSees. Firstly, the applicability of pushover analysis based on the fundamental mode is discussed. Secondly, an improved pushover analysis method considering the contribution of higher modes is proposed, and the applicability on composite rigid frame bridges under bi-directional earthquake is verified. Based on this method, an approach to predict the displacement responses of composite rigid frame bridge under random bi-directional seismic excitations by revising the elasto-plastic demand curve is also proposed. It is observed that the developed method yield a good estimate on the responses of composite rigid frame bridges under bi-directional seismic excitations.

  9. Cell-Type-Specific Sensorimotor Processing in Striatal Projection Neurons during Goal-Directed Behavior.

    Science.gov (United States)

    Sippy, Tanya; Lapray, Damien; Crochet, Sylvain; Petersen, Carl C H

    2015-10-21

    Goal-directed sensorimotor transformation drives important aspects of mammalian behavior. The striatum is thought to play a key role in reward-based learning and action selection, receiving glutamatergic sensorimotor signals and dopaminergic reward signals. Here, we obtain whole-cell membrane potential recordings from the dorsolateral striatum of mice trained to lick a reward spout after a whisker deflection. Striatal projection neurons showed strong task-related modulation, with more depolarization and action potential firing on hit trials compared to misses. Direct pathway striatonigral neurons, but not indirect pathway striatopallidal neurons, exhibited a prominent early sensory response. Optogenetic stimulation of direct pathway striatonigral neurons, but not indirect pathway striatopallidal neurons, readily substituted for whisker stimulation evoking a licking response. Our data are consistent with direct pathway striatonigral neurons contributing a "go" signal for goal-directed sensorimotor transformation leading to action initiation. VIDEO ABSTRACT.

  10. Feasibility of asymmetrical flow field-flow fractionation as a method for detecting protective antigen by direct recognition of size-increased target-captured nanoprobes.

    Science.gov (United States)

    Shin, Kayeong; Choi, Jaeyeong; Cho, Jun-Haeng; Yoon, Moon-Young; Lee, Seungho; Chung, Hoeil

    2015-11-27

    Asymmetrical flow field-flow fractionation (AF4) was evaluated as a potential analytical method for detection of a protective antigen (PA), an Anthrax biomarker. The scheme was based on the recognition of altered AF4 retention through the generation of the size-increased Au nanoparticle probes as a result of PA binding, in which a PA-selective peptide was conjugated on the probe surface. In the visible absorption-based AF4 fractograms, the band position shifted to a longer retention time as the PA concentration increased due to the presence of probe bound with PAs. The shift was insignificant when the concentration was relatively low at 84.3pM. To improve sensitivity, two separate probes conjugated with two different peptides able to bind on different PA epitopes were used together. The band shift then became distinguishable even at 84.3pM of PA sample. The formation of larger PA-probe inter-connected species using the dual-probe system was responsible for the enhanced band shift. In parallel, the feasibility of surface-enhanced Raman scattering (SERS) as a potential AF4 detection method was also evaluated. In the off-line SERS fractogram constructed using fractions collected during AF4 separation, a band shift was also observed for the 84.3pM PA sample, and the band intensity was higher when using the dual-probe system. The combination of AF4 and SERS is promising for the detection of PA and will become a potential tool if the reproducibility of SERS measurement is improved.

  11. The agreement between parent-reported and directly measured child language and parenting behaviors

    Directory of Open Access Journals (Sweden)

    Shannon K Bennetts

    2016-11-01

    Full Text Available Parenting behaviors are commonly targeted in early interventions to improve children’s language development. Accurate measurement of both parenting behaviors and children’s language outcomes is thus crucial for sensitive assessment of intervention outcomes. To date, only a small number of studies have compared parent-reported and directly measured behaviors, and these have been hampered by small sample sizes and inaccurate statistical techniques, such as correlations. The Bland-Altman Method and Reduced Major Axis regression represent more reliable alternatives because they allow us to quantify fixed and proportional bias between measures. In this study, we draw on data from two Australian early childhood cohorts (N= 201 parents and slow-to-talk toddlers aged 24 months; and N=218 parents and children aged 6-36 months experiencing social adversity to (1 examine agreement and quantify bias between parent-reported and direct measures, and (2 to determine socio-demographic predictors of the differences between parent-reported and direct measures. Measures of child language and parenting behaviors were collected from parents and their children. Our findings support the utility of the Bland-Altman Method and Reduced Major Axis regression in comparing measurement methods. Results indicated stronger agreement between parent-reported and directly measured child language, and poorer agreement between measures of parenting behaviors. Child age was associated with difference scores for child language; however the direction varied for each cohort. Parents who rated their child’s temperament as more difficult tended to report lower language scores on the parent questionnaire, compared to the directly measured scores. Older parents tended to report lower parenting responsiveness on the parent questionnaire, compared to directly measured scores. Finally, speaking a language other than English was associated with less responsive parenting behaviors on the

  12. The Agreement between Parent-Reported and Directly Measured Child Language and Parenting Behaviors.

    Science.gov (United States)

    Bennetts, Shannon K; Mensah, Fiona K; Westrupp, Elizabeth M; Hackworth, Naomi J; Reilly, Sheena

    2016-01-01

    Parenting behaviors are commonly targeted in early interventions to improve children's language development. Accurate measurement of both parenting behaviors and children's language outcomes is thus crucial for sensitive assessment of intervention outcomes. To date, only a small number of studies have compared parent-reported and directly measured behaviors, and these have been hampered by small sample sizes and inaccurate statistical techniques, such as correlations. The Bland-Altman Method and Reduced Major Axis regression represent more reliable alternatives because they allow us to quantify fixed and proportional bias between measures. In this study, we draw on data from two Australian early childhood cohorts (N = 201 parents and slow-to-talk toddlers aged 24 months; and N = 218 parents and children aged 6-36 months experiencing social adversity) to (1) examine agreement and quantify bias between parent-reported and direct measures, and (2) to determine socio-demographic predictors of the differences between parent-reported and direct measures. Measures of child language and parenting behaviors were collected from parents and their children. Our findings support the utility of the Bland-Altman Method and Reduced Major Axis regression in comparing measurement methods. Results indicated stronger agreement between parent-reported and directly measured child language, and poorer agreement between measures of parenting behaviors. Child age was associated with difference scores for child language; however, the direction varied for each cohort. Parents who rated their child's temperament as more difficult tended to report lower language scores on the parent questionnaire, compared to the directly measured scores. Older parents tended to report lower parenting responsiveness on the parent questionnaire, compared to directly measured scores. Finally, speaking a language other than English was associated with less responsive parenting behaviors on the videotaped

  13. Discrimination of Effects between Directional and Nondirectional Information of Auditory Warning on Driving Behavior

    Directory of Open Access Journals (Sweden)

    Yuting Zhang

    2015-01-01

    Full Text Available This study examines the impacts of directional and nondirectional auditory warning information in a collision warning system (CWS on driving behavior. The data on driving behavior is collected through experiment, with scenarios containing unexpected hazard events that include different warning content. As drivers approached the collision event, either a CWS auditory warning was given or no warning was given for a reference group. Discriminant analysis was used to investigate the relationship between directional auditory warning information and driving behavior. In the experiment, the CWS warnings significantly reduced brake reaction time and prompted drivers to press the brake pedal more heavily, demonstrating the effectiveness of CWS warnings in alerting drivers to avoid red-light running (RLR vehicles when approaching a signalized intersection. Providing a clear warning with directional information about an urgent hazard event could give drivers adequate time to prepare for the potential collision. In terms of deceleration, a directional information warning was shown to greatly help drivers react to critical events at signalized intersections with more moderate braking. From these results, requirements can be derived for the design of effective warning strategies for critical intersections.

  14. Effects of Strand Lay Direction and Crossing Angle on Tribological Behavior of Winding Hoist Rope

    OpenAIRE

    Xiang-dong Chang; Yu-xing Peng; Zhen-cai Zhu; Xian-sheng Gong; Zhang-fa Yu; Zhen-tao Mi; Chun-ming Xu

    2017-01-01

    Friction and wear behavior exists between hoisting ropes that are wound around the drums of a multi-layer winding hoist. It decreases the service life of ropes and threatens mine safety. In this research, a series of experiments were conducted using a self-made test rig to study the effects of the strand lay direction and crossing angle on the winding rope’s tribological behavior. Results show that the friction coefficient in the steady-state period shows a decreasing tendency with an increas...

  15. Influence of Direct Current Electric Field on Corrosion Behavior of Tin Under a Thin Electrolyte Layer

    Science.gov (United States)

    Huang, H. L.; Bu, F. R.; Tian, J.; Liu, D.

    2017-08-01

    The influence of a direct current electric field (DCEF) on corrosion behavior of tin under a thin electrolyte layer was investigated based on an array electrode technology by polarization, electrochemical impedance spectroscopy and surface analysis. The experimental results indicate that the corrosion rate of tin near the positive plate of DCEF increases with increased electric field intensity, which could be attributed to the acceleration of the migration of ions, the removal of corrosion products under DCEF and the damage of tin surface oxide film. Furthermore, tin at different positions in a DCEF exhibits different corrosion behavior, which could be ascribed to the difference of the local corrosion environment caused by the DCEF.

  16. The Role of Blogs in Consumer Behavior – Knowledge and Direction

    DEFF Research Database (Denmark)

    Sørensen, Jeanne

    This paper explores the role of blogs as a form of social media and how blogs might influence consumers’ behavior. Blogs have gained limited attention so far in scholarly research the focus has primarily been directed at blogs as a communication channel for companies and at what motivates bloggers...... to engage in such an activity. Little attention has been paid to the meaning of blogs for consumers as readers and how blogs influence consumer behavior. The consumer perspective is crucial to explore to gain a better understanding of the potential of blogs and how companies can manage this aspect...

  17. Study of Rayleigh-backscattering induced coherence collapse in an asymmetric DFB FL sensor

    Science.gov (United States)

    Liu, Wen; Ma, Lina; Hu, Zhengliang; Feng, Ying; Yang, Huayong

    2016-09-01

    Rayleigh-back scattering induced coherence collapse of an asymmetric distributed feedback fiber laser (DFB FL) sensor is investigated using a composite cavity model. The coherence collapse threshold condition of the asymmetric DFB FL sensor is measured. The DFB FL sensor shows different dynamic behaviors in different pump configurations. According to the asymmetric behavior to the external optical feedback, a novel method to find the actual phase shift position of the asymmetric DFB FL sensor is presented.

  18. Oxytocin receptor gene polymorphisms are associated with human directed social behavior in dogs (Canis familiaris).

    Science.gov (United States)

    Kis, Anna; Bence, Melinda; Lakatos, Gabriella; Pergel, Enikő; Turcsán, Borbála; Pluijmakers, Jolanda; Vas, Judit; Elek, Zsuzsanna; Brúder, Ildikó; Földi, Levente; Sasvári-Székely, Mária; Miklósi, Adám; Rónai, Zsolt; Kubinyi, Enikő

    2014-01-01

    The oxytocin system has a crucial role in human sociality; several results prove that polymorphisms of the oxytocin receptor gene are related to complex social behaviors in humans. Dogs' parallel evolution with humans and their adaptation to the human environment has made them a useful species to model human social interactions. Previous research indicates that dogs are eligible models for behavioral genetic research, as well. Based on these previous findings, our research investigated associations between human directed social behaviors and two newly described (-212AG, 19131AG) and one known (rs8679684) single nucleotide polymorphisms (SNPs) in the regulatory regions (5' and 3' UTR) of the oxytocin receptor gene in German Shepherd (N = 104) and Border Collie (N = 103) dogs. Dogs' behavior traits have been estimated in a newly developed test series consisting of five episodes: Greeting by a stranger, Separation from the owner, Problem solving, Threatening approach, Hiding of the owner. Buccal samples were collected and DNA was isolated using standard protocols. SNPs in the 3' and 5' UTR regions were analyzed by polymerase chain reaction based techniques followed by subsequent electrophoresis analysis. The gene-behavior association analysis suggests that oxytocin receptor gene polymorphisms have an impact in both breeds on (i) proximity seeking towards an unfamiliar person, as well as their owner, and on (ii) how friendly dogs behave towards strangers, although the mediating molecular regulatory mechanisms are yet unknown. Based on these results, we conclude that similarly to humans, the social behavior of dogs towards humans is influenced by the oxytocin system.

  19. [Association between self-directed learning behaviors, socio-demographic and academic variables among medical students].

    Science.gov (United States)

    Fasce H, Eduardo; Ortega B, Javiera; Pérez V, Cristhian; Márquez U, Carolina; Parra P, Paula; Ortiz M, Liliana; Matus, Olga

    2013-09-01

    Medical education must encourage autonomous learning behaviors among students. However the great income profile disparity among university students may influence their capacity to acquire such skills. To assess the association between self-directed learning, socio-demographic and academic variables. The self-directed learning readiness scale was applied to 202 medical students aged between 17 and 25 years (64% males). Simultaneously information about each surveyed participant was obtained from the databases of the medical school. There is an association between socio-demographic and academic variables with the general scale of self-directed learning and the subscales learning planning and willingness to learn. Participants coming from municipal schools have a greater willingness to learn than their counterparts coming from subsidized and private schools. High school grades are related to self-directed learning and the subscales learning planning and self-assessment. Among the surveyed medical students, there is a relationship between self-directed learning behaviors, the type of school where they come from and the grades that they obtained during high school.

  20. Clustering as an EDA Method: The Case of Pedestrian Directional Flow Behavior

    Directory of Open Access Journals (Sweden)

    Ma. Regina E. Estuar

    2010-01-01

    Full Text Available Given the data of pedestrian trajectories in NTXY format, three clustering methods of K Means, Expectation Maximization (EM and Affinity Propagation were utilized as Exploratory Data Analysis to find the pattern of pedestrian directional flow behavior. The analysis begins without a prior notion regarding the structure of the pattern and it consequentially infers the structure of directional flow pattern. Significant similarities in patterns for both individual and instantaneous walking angles based on EDA method are reported and explained in case studies

  1. Lateralization of Eye Use in Cuttlefish: Opposite Direction for Anti-Predatory and Predatory Behaviors

    Science.gov (United States)

    Schnell, Alexandra K.; Hanlon, Roger T.; Benkada, Aïcha; Jozet-Alves, Christelle

    2016-01-01

    Vertebrates with laterally placed eyes typically exhibit preferential eye use for ecological activities such as scanning for predators or prey. Processing visual information predominately through the left or right visual field has been associated with specialized function of the left and right brain. Lateralized vertebrates often share a general pattern of lateralized brain function at the population level, whereby the left hemisphere controls routine behaviors and the right hemisphere controls emergency responses. Recent studies have shown evidence of preferential eye use in some invertebrates, but whether the visual fields are predominately associated with specific ecological activities remains untested. We used the European common cuttlefish, Sepia officinalis, to investigate whether the visual field they use is the same, or different, during anti-predatory, and predatory behavior. To test for lateralization of anti-predatory behavior, individual cuttlefish were placed in a new environment with opaque walls, thereby obliging them to choose which eye to orient away from the opaque wall to scan for potential predators (i.e., vigilant scanning). To test for lateralization of predatory behavior, individual cuttlefish were placed in the apex of an isosceles triangular arena and presented with two shrimp in opposite vertexes, thus requiring the cuttlefish to choose between attacking a prey item to the left or to the right of them. Cuttlefish were significantly more likely to favor the left visual field to scan for potential predators and the right visual field for prey attack. Moreover, individual cuttlefish that were leftward directed for vigilant scanning were predominately rightward directed for prey attack. Lateralized individuals also showed faster decision-making when presented with prey simultaneously. Cuttlefish appear to have opposite directions of lateralization for anti-predatory and predatory behavior, suggesting that there is functional specialization of

  2. Lateralization of eye use in cuttlefish: opposite direction for anti-predatory and predatory behaviors.

    Directory of Open Access Journals (Sweden)

    Alexandra Kerstin Schnell

    2016-12-01

    Full Text Available Vertebrates with laterally placed eyes typically exhibit preferential eye use for ecological activities such as scanning for predators or prey. Processing visual information predominately through the left or right visual field has been associated with specialized function of the left and right brain. Lateralized vertebrates often share a general pattern of lateralized brain function at the population level, whereby the left hemisphere controls routine behaviors and the right hemisphere controls emergency responses. Recent studies have shown evidence of preferential eye use in some invertebrates, but whether the visual fields are predominately associated with specific ecological activities remains untested. We used the European common cuttlefish, Sepia officinalis, to investigate whether the visual field they use is the same, or different, during anti-predatory and predatory behavior. To test for lateralization of anti-predatory behavior, individual cuttlefish were placed in a new environment with opaque walls, thereby obliging them to choose which eye to orient away from the opaque wall to scan for potential predators (i.e. vigilant scanning. To test for lateralization of predatory behavior, individual cuttlefish were placed in the apex of an isosceles triangular arena and presented with two shrimp in opposite vertexes, thus requiring the cuttlefish to choose between attacking a prey item to the left or to the right of them. Cuttlefish were significantly more likely to favor the left visual field to scan for potential predators and the right visual field for prey attack. Moreover, individual cuttlefish that were leftward directed for vigilant scanning were predominately rightward directed for prey attack. Lateralized individuals also showed faster decision-making when presented with prey simultaneously. Cuttlefish appear to have opposite directions of lateralization for anti-predatory and predatory behavior, suggesting that there is functional

  3. Neuroevolution Results in Emergence of Short-Term Memory for Goal-Directed Behavior

    CERN Document Server

    Lakhman, Konstantin

    2012-01-01

    Animals behave adaptively in the environment with multiply competing goals. Understanding of the mechanisms underlying such goal-directed behavior remains a challenge for neuroscience as well for adaptive system research. To address this problem we developed an evolutionary model of adaptive behavior in the multigoal stochastic environment. Proposed neuroevolutionary algorithm is based on neuron's duplication as a basic mechanism of agent's recurrent neural network development. Results of simulation demonstrate that in the course of evolution agents acquire the ability to store the short-term memory and, therefore, use it in behavioral strategies with alternative actions. We found that evolution discovered two mechanisms for short-term memory. The first mechanism is integration of sensory signals and ongoing internal neural activity, resulting in emergence of cell groups specialized on alternative actions. And the second mechanism is slow neurodynamical processes that makes possible to code the previous behav...

  4. Measuring Bystander Behavior in the Context of Sexual Violence Prevention: Lessons Learned and New Directions.

    Science.gov (United States)

    McMahon, Sarah; Palmer, Jane E; Banyard, Victoria; Murphy, Megan; Gidycz, Christine A

    2015-07-05

    Bystander intervention is receiving increased attention as a potential sexual violence prevention strategy, especially to address campus sexual assault. Rather than focusing on potential perpetrators or victims, the bystander approach engages all members of a community to take action. A growing body of evaluative work demonstrates that bystander intervention education programs yield increased positive attitudes and behaviors related to sexual violence and greater willingness to intervene in pro-social ways. Future program outcome studies, however, would benefit from more refined measures of bystander action as it is a key variable that prevention education programs attempt to influence. The purpose of the current article is to present key issues, identified by four different research teams, on the measurement of bystander behavior related to sexual violence in the context of college campuses. Comparisons among the methods are made to suggest both lessons learned and new directions for bystander behavior measurement using self-report surveys in program evaluation. © The Author(s) 2015.

  5. Pathways to adult sexual revictimization: direct and indirect behavioral risk factors across the lifespan.

    Science.gov (United States)

    Fargo, Jamison D

    2009-11-01

    The purpose of this study is to investigate direct and indirect social and behavioral risk factors for adult sexual revictimization. Participants include 147 adult, predominantly African American (88%) women, 59% of whom had a documented history of child sexual abuse. Participants are interviewed in adulthood about adolescent and adult sexual victimization as well as other background and lifestyle characteristics. Structural equation modeling indicates that the relationship between child and adolescent sexual victimization is indirect, mediated by adolescent risk-taking behavior. The relationship between adolescent and adult sexual victimization is also indirect, mediated by risky sexual behavior. The residual effects of early childhood family environment and childhood physical abuse also indirectly predict sexual revictimization. Results provide empirical support for the general supposition that the relationship between child and adult sexual victimization is complex and that many intermediary factors differentially affect risk for a heightened vulnerability to sexual revictimization.

  6. Fold catastrophe model of dynamic pillar failure in asymmetric mining

    Institute of Scientific and Technical Information of China (English)

    PAN Yue; LI Ai-wu; QI Yun-song

    2009-01-01

    A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well as. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This plot contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions.

  7. Emotion and goal-directed behavior: ERP evidence on cognitive and emotional conflict

    OpenAIRE

    Zinchenko, Artyom; Kanske, Philipp; Obermeier, Christian; Schröger, Erich; Kotz, Sonja A.

    2015-01-01

    Cognitive control supports goal-directed behavior by resolving conflict among opposing action tendencies. Emotion can trigger cognitive control processes, thus speeding up conflict processing when the target dimension of stimuli is emotional. However, it is unclear what role emotionality of the target dimension plays in the processing of emotional conflict (e.g. in irony). In two EEG experiments, we compared the influence of emotional valence of the target (emotional, neutral) in cognitive an...

  8. Repeated transcranial direct current stimulation prevents abnormal behaviors associated with abstinence from chronic nicotine consumption.

    Science.gov (United States)

    Pedron, Solène; Monnin, Julie; Haffen, Emmanuel; Sechter, Daniel; Van Waes, Vincent

    2014-03-01

    Successful available treatments to quit smoking remain scarce. Recently, the potential of transcranial direct current stimulation (tDCS) as a tool to reduce craving for nicotine has gained interest. However, there is no documented animal model to assess the neurobiological mechanisms of tDCS on addiction-related behaviors. To address this topic, we have developed a model of repeated tDCS in mice and used it to validate its effectiveness in relieving nicotine addiction. Anodal repeated tDCS was applied over the frontal cortex of Swiss female mice. The stimulation electrode (anode) was fixed directly onto the cranium, and the reference electrode was placed onto the ventral thorax. A 2 × 20 min/day stimulation paradigm for five consecutive days was used (0.2 mA). In the first study, we screened for behaviors altered by the stimulation. Second, we tested whether tDCS could alleviate abnormal behaviors associated with abstinence from nicotine consumption. In naive animals, repeated tDCS had antidepressant-like properties 3 weeks after the last stimulation, improved working memory, and decreased conditioned place preference for nicotine without affecting locomotor activity and anxiety-related behavior. Importantly, abnormal behaviors associated with chronic nicotine exposure (ie, depression-like behavior, increase in nicotine-induced place preference) were normalized by repeated tDCS. Our data show for the first time in an animal model that repeated tDCS is a promising, non-expensive clinical tool that could be used to reduce smoking craving and facilitate smoking cessation. Our animal model will be useful to investigate the mechanisms underlying the effects of tDCS on addiction and other psychiatric disorders.

  9. Neurocognitive abnormalities during comprehension of real-world goal-directed behaviors in schizophrenia.

    Science.gov (United States)

    Sitnikova, Tatiana; Goff, Donald; Kuperberg, Gina R

    2009-05-01

    Origins of impaired adaptive functioning in schizophrenia remain poorly understood. Behavioral disorganization may arise from an abnormal reliance on common combinations between concepts stored in semantic memory. Avolition-apathy may be related to deficits in using goal-related requirements to flexibly plan behavior. The authors recorded event-related potentials (ERPs) in 16 patients with medicated schizophrenia and 16 healthy controls in a novel video paradigm presenting congruous or incongruous objects in real-world activities. All incongruous objects were contextually inappropriate, but the incongruous scenes varied in comprehensibility. Psychopathology was assessed with the Scales for the Assessment of Positive and Negative Symptoms (SAPS/SANS) and the Brief Psychiatric Rating Scale. In patients, an N400 ERP, thought to index activity in semantic memory, was abnormally enhanced to less comprehensible incongruous scenes, and larger N400 priming was associated with disorganization severity. A P600 ERP, which may index flexible object-action integration based on goal-related requirements, was abnormally attenuated in patients, and its smaller magnitude was associated with the SANS rating of impersistence at work or school (goal-directed behavior). Thus, distinct neurocognitive abnormalities may underlie disorganization and goal-directed behavior deficits in schizophrenia.

  10. Latent Toxoplasma gondii infection leads to deficits in goal-directed behavior in healthy elderly.

    Science.gov (United States)

    Beste, Christian; Getzmann, Stephan; Gajewski, Patrick D; Golka, Klaus; Falkenstein, Michael

    2014-05-01

    Goal-directed behavior is well-known to show declines in elderly individuals, possibly because of alterations in dopaminergic neural transmission. The dopaminergic system is modulated by a number of other different factors. One of these factors, which has attracted a considerable amount of interest in neurobiology, but has only rarely been examined with respect to its possible modulatory role for cognitive functions in elderly individuals, is latent Toxoplasma gondii (T. gondii) infection. Latent T. gondii infection may be of relevance to goal-directed behavior as it alters dopaminergic neural transmission. We examine goal-directed behavior in T. gondii IgG positive and negative elderly subjects in auditory distraction paradigm. We apply event-related potentials to examine which cognitive subprocesses are affected by latent T. gondii infection on a neurophysiological level. We show that latent T. gondii infection compromises the management of auditory distraction in elderly by specifically delaying processes of attentional allocation and disengagement. The results show that latent T. gondii infection is neglected but an important neurobiological modulator of cognitive functions in elderly individuals.

  11. Motivational states activate distinct hippocampal representations to guide goal-directed behaviors.

    Science.gov (United States)

    Kennedy, Pamela J; Shapiro, Matthew L

    2009-06-30

    Adaptive behaviors are guided by motivation and memory. Motivational states specify goals, and memory can inform motivated behavior by providing detailed records of past experiences when goals were obtained. These 2 fundamental processes interact to guide animals to biologically relevant targets, but the neuronal mechanisms that integrate them remain unknown. To investigate these mechanisms, we recorded unit activity from the same population of hippocampal neurons as rats performed identical tasks while either food or water deprived. We compared the influence of motivational state (hunger and thirst), memory demand, and spatial behavior in 2 tasks: hippocampus-dependent contextual memory retrieval and hippocampus-independent random foraging. We found that: (i) hippocampal coding was most strongly influenced by motivational state during contextual memory retrieval, when motivational cues were required to select among remembered, goal-directed actions in the same places; (ii) the same neuronal populations were relatively unaffected by motivational state during random foraging, when hunger and thirst were incidental to behavior, and signals derived from deprivation states thus informed, but did not determine, hippocampal coding; and (iii) "prospective coding" in the contextual retrieval task was not influenced by allocentric spatial trajectory, but rather by the animal's deprivation state and the associated, non-spatial target, suggesting that hippocampal coding includes a wide range of predictive associations. The results show that beyond coding spatiotemporal context, hippocampal representations encode the relationships between internal states, the external environment, and action to provide a mechanism by which motivation and memory are coordinated to guide behavior.

  12. Multi-item direct behavior ratings: Dependability of two levels of assessment specificity.

    Science.gov (United States)

    Volpe, Robert J; Briesch, Amy M

    2015-09-01

    Direct Behavior Rating-Multi-Item Scales (DBR-MIS) have been developed as formative measures of behavioral assessment for use in school-based problem-solving models. Initial research has examined the dependability of composite scores generated by summing all items comprising the scales. However, it has been argued that DBR-MIS may offer assessment of 2 levels of behavioral specificity (i.e., item-level, global composite-level). Further, it has been argued that scales can be individualized for each student to improve efficiency without sacrificing technical characteristics. The current study examines the dependability of 5 items comprising a DBR-MIS designed to measure classroom disruptive behavior. A series of generalizability theory and decision studies were conducted to examine the dependability of each item (calls out, noisy, clowns around, talks to classmates and out of seat), as well as a 3-item composite that was individualized for each student. Seven graduate students rated the behavior of 9 middle-school students on each item over 3 occasions. Ratings were based on 10-min video clips of students during mathematics instruction. Separate generalizability and decision studies were conducted for each item and for a 3-item composite that was individualized for each student based on the highest rated items on the first rating occasion. Findings indicate favorable dependability estimates for 3 of the 5 items and exceptional dependability estimates for the individualized composite.

  13. Total Synthesis and Stereochemical Assignment of Delavatine A: Rh-Catalyzed Asymmetric Hydrogenation of Indene-Type Tetrasubstituted Olefins and Kinetic Resolution through Pd-Catalyzed Triflamide-Directed C-H Olefination.

    Science.gov (United States)

    Zhang, Zhongyin; Wang, Jinxin; Li, Jian; Yang, Fan; Liu, Guodu; Tang, Wenjun; He, Weiwei; Fu, Jian-Jun; Shen, Yun-Heng; Li, Ang; Zhang, Wei-Dong

    2017-03-08

    Delavatine A (1) is a structurally unusual isoquinoline alkaloid isolated from Incarvillea delavayi. The first and gram-scale total synthesis of 1 was accomplished in 13 steps (the longest linear sequence) from commercially available starting materials. We exploited an isoquinoline construction strategy and developed two reactions, namely Rh-catalyzed asymmetric hydrogenation of indene-type tetrasubstituted olefins and kinetic resolution of β-alkyl phenylethylamine derivatives through Pd-catalyzed triflamide-directed C-H olefination. The substrate scope of the first reaction covered unfunctionalized olefins and those containing polar functionalities such as sulfonamides. The kinetic resolution provided a collection of enantioenriched indane and tetralin-based triflamides, including those bearing quaternary chiral centers. The selectivity factor (s) exceeded 100 for a number of substrates. These reactions enabled two different yet related approaches to a key intermediate 28 in excellent enantiopurity. In the synthesis, the triflamide served as not only an effective directing group for C-H bond activation but also a versatile functional group for further elaborations. The relative and absolute configurations of delavatine A were unambiguously assigned by the syntheses of the natural product and its three stereoisomers. Their cytotoxicity against a series of cancer cell lines were evaluated.

  14. Verification of extended model of goal directed behavior applied on aggression

    Directory of Open Access Journals (Sweden)

    Katarína Vasková

    2016-01-01

    Full Text Available The study was aimed to verify Model of Goal Directed Behavior (EMGB by Perugini and Bagozzi (2001 applied on aggression by Richetin, Richardson and Boykin (2011. Two different studies were performed. Firstly original form of model was verified. In the second study, modification of EMGB through new conceptualization of scale of perceived behavioral control was executed. The research sample consisted together from 385 students of University of P.J. Šafárik and High school in Košice (182 respondents (78 men, 104 women with average age 20,84 years and standard deviation 1,94, who were involved in first study and 203 students (49 men and 154 women, with average age 19,71 and standard deviation 1,99 participated in second study who were administrated questionnaire by Richetin et al. (2011 and Richardson Conflict Response Questionnaire (Richardson & Green, 2006. Expectancy of comparable relationships between particular factors of EMGB in comparison to its published original version was verified. Data were analyzed by structural equation modeling. In first study was shown insufficient fit of EMGB model. There were hypothesized two main sources of problems. At first, weak relationship between attitudes and behavioral desire was shown. Following statistical procedures confirmed its direct impact on intention, what is in correspondence with another studies (see Leone, Perugini & Ercolani, 2004, Perugini & Bagozzi, 2001, Richetin et al., 2011. Second source of problems was identified in factor named perceived behavioral control. Difficulties from our point of view lied in conceptualization of the term and its subsequent measurement. In the second study was involved new conceptualization of control. It corresponded with Baumeister´s understanding of selfcontrol as asserting control over one´s emotions, thoughts and behavior. After this modification sufficient fit of EMGB was shown. Besides this, factor of self-control was the strongest predictor of

  15. Crowding increases salivary cortisol but not self-directed behavior in captive baboons.

    Science.gov (United States)

    Pearson, Brandon L; Reeder, DeeAnn M; Judge, Peter G

    2015-04-01

    Reduced space can lead to crowding in social animals. Crowding increases the risk of agonistic interactions that, in turn, may require additional physiological defensive coping mechanisms affecting health. To determine the stress induced from increased social density in a group of nineteen baboons living in an indoor/outdoor enclosure, saliva cortisol levels and rates of anxiety-related behavior were analyzed across two unique crowding episodes. Initially, mean salivary cortisol levels when animals were restricted to their indoor quarters were compared to those when they also had access to their larger outdoor enclosure. Then, mean cortisol levels were compared before, during, and after two distinct crowding periods of long and short duration. Crowding resulted in significantly elevated cortisol during crowding periods compared to non-crowded periods. Cortisol levels returned to baseline following two crowding episodes contrasting in their length and ambient climate conditions. These cortisol elevations indicate greater metabolic costs of maintaining homeostasis under social stress resulting from reduced space. Self-directed behavior, conversely, was not reliably elevated during crowding. Results suggest that the potential for negative social interactions, and/or the uncertainty associated with social threat can cause physiological stress responses detected by salivary cortisol. Self-directed behavioral measures of stress may constitute inadequate indicators of social stress in colony-housed monkeys or represent subjective emotional arousal unrelated to hypothalamic-pituitary adrenal axis activation.

  16. Parent-directed cognitive behavioral therapy for young anxious children: a pilot study.

    Science.gov (United States)

    van der Sluis, Cathy M; van der Bruggen, Corine O; Brechman-Toussaint, Margaret L; Thissen, Michèl A P; Bögels, Susan M

    2012-09-01

    Anxiety in children age 8 years and above has been successfully treated with cognitive behavioral therapy (CBT). However, the efficacy of CBT for anxious children ages 4-7 years has not, to date, been fully investigated. This paper piloted a CBT intervention targeting child anxiety that was delivered exclusively to parents of 26 children with anxiety symptoms ages 4-7 years. The intervention consisted of four 2-hour group sessions of four to six parents (couples). These group sessions were followed by four individual telephone sessions, once per week across a 4-week period. The pre- and postintervention assessment involved measures of multiple constructs of child anxiety (anxiety symptoms, children's fears, behavioral inhibition, and internalizing symptoms) from multiple informants (parents, children, and teachers). Parents also reported parenting strategies they were likely to use to manage their children's anxiety pre- and postintervention. Results indicated a significant decrease in child anxiety and behavioral inhibition as reported by parents and teachers. Furthermore, mothers reported significant increases in their use of positive reinforcement, and modeling and reassurance, and a significant decrease in their use of reinforcement of dependency directly after treatment. Taken together, parent-directed CBT appears to be an effective approach for treating children ages 4-7 years with anxiety symptoms. Limitations of the current research are discussed.

  17. Ethanol seeking by Long Evans rats is not always a goal-directed behavior.

    Directory of Open Access Journals (Sweden)

    Regina A Mangieri

    Full Text Available BACKGROUND: Two parallel and interacting processes are said to underlie animal behavior, whereby learning and performance of a behavior is at first via conscious and deliberate (goal-directed processes, but after initial acquisition, the behavior can become automatic and stimulus-elicited (habitual. With respect to instrumental behaviors, animal learning studies suggest that the duration of training and the action-outcome contingency are two factors involved in the emergence of habitual seeking of "natural" reinforcers (e.g., sweet solutions, food or sucrose pellets. To rigorously test whether behaviors reinforced by abused substances such as ethanol, in particular, similarly become habitual was the primary aim of this study. METHODOLOGY/PRINCIPAL FINDINGS: Male Long Evans rats underwent extended or limited operant lever press training with 10% sucrose/10% ethanol (10S10E reinforcement (variable interval (VI or (VR ratio schedule of reinforcement, or with 10% sucrose (10S reinforcement (VI schedule only. Once training and pretesting were complete, the impact of outcome devaluation on operant behavior was evaluated after lithium chloride injections were paired with the reinforcer, or unpaired 24 hours later. After limited, but not extended instrumental training, lever pressing by groups trained under VR with 10S10E and under VI with 10S was sensitive to outcome devaluation. In contrast, responding by both the extended and limited training 10S10E VI groups was not sensitive to ethanol devaluation during the test for habitual behavior. CONCLUSIONS/SIGNIFICANCE: Operant behavior by rats trained to self-administer an ethanol-sucrose solution showed variable sensitivity to a change in the value of ethanol, with relative insensitivity developing sooner in animals that received time-variable ethanol reinforcement during training sessions. One important implication, with respect to substance abuse in humans, is that initial learning about the

  18. Transcranial direct current stimulation of the frontal-parietal-temporal area attenuates smoking behavior.

    Science.gov (United States)

    Meng, Zhiqiang; Liu, Chang; Yu, Chengyang; Ma, Yuanye

    2014-07-01

    Many brain regions are involved in smoking addiction (e.g. insula, ventral tegmental area, prefrontal cortex and hippocampus), and the manipulation of the activity of these brain regions can show a modification of smoking behavior. Low current transcranial direct current stimulation (tDCS) is a noninvasive way to manipulate cortical excitability, and thus brain function and associated behaviors. In this study, we examined the effects of inhibiting the frontal-parietal-temporal association area (FPT) on attention bias to smoking-related cues and smoking behavior in tobacco users. This inhibition is induced by cathodal tDCS stimulation. We tested three stimulation conditions: 1) bilateral cathodal over both sides of FPT; 2) cathodal over right FPT; and 3) sham-tDCS. Visual attention bias to smoking-related cues was evaluated using an eye tracking system. The measurement for smoking behavior was the number of daily cigarettes consumed before and after tDCS treatment. We found that, after bilateral cathodal stimulation of the FPT area, while the attention to smoking-related cues showed a decreased trend, the effects were not significantly different from sham stimulation. The daily cigarette consumption was reduced to a significant level. These effects were not seen under single cathodal tDCS or sham-tDCS. Our results show that low current tDCS of FPT area attenuates smoking cue-related attention and smoking behavior. This non-invasive brain stimulation technique, targeted at FPT areas, might be a promising method for treating smoking behavior.

  19. Oxytocin receptor gene polymorphisms are associated with human directed social behavior in dogs (Canis familiaris.

    Directory of Open Access Journals (Sweden)

    Anna Kis

    Full Text Available The oxytocin system has a crucial role in human sociality; several results prove that polymorphisms of the oxytocin receptor gene are related to complex social behaviors in humans. Dogs' parallel evolution with humans and their adaptation to the human environment has made them a useful species to model human social interactions. Previous research indicates that dogs are eligible models for behavioral genetic research, as well. Based on these previous findings, our research investigated associations between human directed social behaviors and two newly described (-212AG, 19131AG and one known (rs8679684 single nucleotide polymorphisms (SNPs in the regulatory regions (5' and 3' UTR of the oxytocin receptor gene in German Shepherd (N = 104 and Border Collie (N = 103 dogs. Dogs' behavior traits have been estimated in a newly developed test series consisting of five episodes: Greeting by a stranger, Separation from the owner, Problem solving, Threatening approach, Hiding of the owner. Buccal samples were collected and DNA was isolated using standard protocols. SNPs in the 3' and 5' UTR regions were analyzed by polymerase chain reaction based techniques followed by subsequent electrophoresis analysis. The gene-behavior association analysis suggests that oxytocin receptor gene polymorphisms have an impact in both breeds on (i proximity seeking towards an unfamiliar person, as well as their owner, and on (ii how friendly dogs behave towards strangers, although the mediating molecular regulatory mechanisms are yet unknown. Based on these results, we conclude that similarly to humans, the social behavior of dogs towards humans is influenced by the oxytocin system.

  20. 非对称双向多中继系统机会式网络编码中断概率分析%Outage Probability Analysis of Opportunistic Network Coding on Asymmetrical Bi-directional Multi-Relay System

    Institute of Scientific and Technical Information of China (English)

    梁文文; 田华; 徐友云; 许魁; 陈小杰

    2013-01-01

    A practical asymmetrical bi-directional multi-relay system model is firstly constructed, and then an outage probability expression of the model is given based on opportunistic relay scheme and network coding, which is proved accurate by Monte Carlo simulations. Secondly, it analyzes the system average outage probability with different situations of power allocation coefficient, locations of the relay nodes and the number of relay nodes, indicating the inherent relationship between power allocation coefficient and total system power, as well as the number of relay nodes. Simulation results show that the optimal system outage performance of asymmetrical bi-directional multi-relay system based on opportunistic relay scheme and network coding is attained when power allocation coefficient is chosen at 0. 6 or about 0. 6. It can be known that the location of relay nodes is an important factor for the problem of system outage probability.%建立了一个实际的非对称双向多中继系统模型,并采用机会中继策略,推导出了该模型在译码转发方式下采用网络编码时的中断概率表达式,Monte Carlo仿真和理论值吻合,充分验证了该表达式的正确性.分析了不同中继节点位置、不同中继节点个数和不同功率分配因子等情况下的系统中断性能,揭示了最优功率分配因子与中继节点个数和位置以及系统总功率的内在关系.仿真结果表明,在非对称双向多中继系统中同时采用网络编码和机会中继策略时,功率分配因子取值为0.6时可获得最佳的系统中断性能,并指出在研究系统中断概率问题时,中继节点位置是一个不可忽略的因素.

  1. Explanations for religious influence on adolescent sexual behavior in Brazil: direct and indirect effects

    Directory of Open Access Journals (Sweden)

    Ana Paula de Andrade Verona

    2011-06-01

    Full Text Available Religion is becoming an important and highly present factor in the lives of many adolescents and young adults in Brazil. In addition to creating more space for them to maintain close relationships and participate actively in a religious environment, some religions have promoted the dissemination of clearer standards and objectives, as well as punitive sanctions, with respect to many aspects of their younger followers' lives, including their sexual behavior. This article examines how religion can affect, direct and indirectly, the sexual behavior of Brazilian adolescents. The main objective of this study is to look for a connection between Christian Smith's theoretical framework, which suggests several mechanisms through which religion can influence the lives of American adolescents, and ethnographic studies conducted in Brazil, as well as quantitative works that have brought attention to social and demographic consequences of recent religious transformations. Even though there is limited empirical evidence as to how the mechanisms of religious involvement work in Brazil, this study concludes that each of Smith's pathways can also be used to explain potential effects of religion on sexual behavior of Brazilian adolescents. This research should encourage empirical studies on such effects in Brazil. Besides the importance of examining the impact of the recent transformations in Brazil religious landscape on demographic phenomena, this topic deserves further consideration from Brazilian demographers because religion is a primary socialization agent of adolescents, and sexual activity is a sphere of human behavior of high importance in its religious applicability.

  2. Dissociable effects of anterior and mediodorsal thalamic lesions on spatial goal-directed behavior.

    Science.gov (United States)

    Alcaraz, Fabien; Naneix, Fabien; Desfosses, Emilie; Marchand, Alain R; Wolff, Mathieu; Coutureau, Etienne

    2016-01-01

    Goal-directed behaviors are thought to be supported by a neural circuit encompassing the prefrontal cortex, the dorsomedial striatum, the amygdala, and, as more recently suggested, the limbic thalamus. Since evidence indicates that the various thalamic nuclei contribute to dissociable functions, we directly compared the functional contribution of the mediodorsal thalamus (MD) and of the anterior thalamic nuclei (ATN) in a new task assessing spatial goal-directed behavior in a cross-maze. Rats sustaining lesions of the mediodorsal or the anterior thalamus were trained to associate each of the two goal arms with a distinctive food reward. Unlike control rats, both lesioned groups failed to express a bias for the goal arm corresponding to the non-devalued outcome following devaluation by sensory-specific satiety. In addition, MD rats were slower than the other groups to complete the trials. When tested for spatial working memory using a standard non-matching-to-place procedure in the same apparatus, ATN rats were severely impaired but MD rats performed as well as controls, even when spatial or temporal challenges were introduced. Finally, all groups displayed comparable breaking points in a progressive ratio test, indicating that the slower choice performance of MD rats did not result from motivational factors. Thus, a spatial task requiring the integration of instrumental and Pavlovian contingencies reveals a fundamental deficit of MD rats in adapting their choice according to goal value. By contrast, the deficit associated with anterior thalamic lesions appears to simply reflect the inability to process spatial information.

  3. The Role of Reciprocity and Directionality of Friendship Ties in Promoting Behavioral Change

    CERN Document Server

    Almaatouq, Abdullah; Pentland, Alex; Shmueli, Erez

    2016-01-01

    Friendship is a fundamental characteristic of human beings and usually assumed to be reciprocal in nature. Despite this common expectation, in reality, not all friendships by default are reciprocal nor created equal. Here, we show that reciprocated friendships are more intimate and they are substantially different from those that are not. We examine the role of reciprocal ties in inducing more effective peer pressure in a cooperative arrangements setting and find that the directionality of friendship ties can significantly limit the ability to persuade others to act. Specifically, we observe a higher behavioral change and more effective peer-influence when subjects shared reciprocal ties with their peers compared to sharing unilateral ones. Moreover, through spreading process simulation, we find that although unilateral ties diffuse behaviors across communities, reciprocal ties play more important role at the early stages of the diffusion process.

  4. Strong static magnetic fields elicit swimming behaviors consistent with direct vestibular stimulation in adult zebrafish.

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    Bryan K Ward

    Full Text Available Zebrafish (Danio rerio offer advantages as model animals for studies of inner ear development, genetics and ototoxicity. However, traditional assessment of vestibular function in this species using the vestibulo-ocular reflex requires agar-immobilization of individual fish and specialized video, which are difficult and labor-intensive. We report that using a static magnetic field to directly stimulate the zebrafish labyrinth results in an efficient, quantitative behavioral assay in free-swimming fish. We recently observed that humans have sustained nystagmus in high strength magnetic fields, and we attributed this observation to magnetohydrodynamic forces acting on the labyrinths. Here, fish were individually introduced into the center of a vertical 11.7T magnetic field bore for 2-minute intervals, and their movements were tracked. To assess for heading preference relative to a magnetic field, fish were also placed in a horizontally oriented 4.7T magnet in infrared (IR light. A sub-population was tested again in the magnet after gentamicin bath to ablate lateral line hair cell function. Free-swimming adult zebrafish exhibited markedly altered swimming behavior while in strong static magnetic fields, independent of vision or lateral line function. Two-thirds of fish showed increased swimming velocity or consistent looping/rolling behavior throughout exposure to a strong, vertically oriented magnetic field. Fish also demonstrated altered swimming behavior in a strong horizontally oriented field, demonstrating in most cases preferred swimming direction with respect to the field. These findings could be adapted for 'high-throughput' investigations of the effects of environmental manipulations as well as for changes that occur during development on vestibular function in zebrafish.

  5. A Review of Direct Observation Research within the Past Decade in the Field of Emotional and Behavioral Disorders

    Science.gov (United States)

    Adamson, Reesha M.; Wachsmuth, Sean T.

    2014-01-01

    This study reviewed prominent journals within the field of emotional and behavioral disorders to identify direct observation approaches, reported reliability statistics, and key features of direct observation. Selected journals were systematically reviewed for the past 10 years identifying and quantifying specific direct observation systems and…

  6. Asymmetric transmission: a generic property of lossy periodic interfaces

    CERN Document Server

    Plum, E; Zheludev, N I

    2010-01-01

    Asymmetric transmission of circularly polarized waves is a well-established property of lossy, anisotropic, two-dimensionally chiral patterns. Here we show that asymmetric transmission can be observed for oblique incidence onto any lossy periodically structured plane. Our results greatly expand the range of natural and artificial materials in which directionally asymmetric transmission can be expected making it a cornerstone electromagnetic effect rather than a curiosity of planar chiral metamaterials. Prime candidates for asymmetric transmission at oblique incidence are rectangular arrays of plasmonic spheres or semiconductor quantum dots, lossy double-periodic gratings and planar metamaterial structures.

  7. Effects of recrystallization on the low cycle fatigue behavior of directionally solidified superalloy DZ40M

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yang; WANG Lei; LI Hongyun; YU Teng; LIU Yang

    2008-01-01

    The effects of recrystallization on low cycle fatigue behavior were investigated on directionally solidified Co-base superalloy DZAOM.Optical microscopy and SEM were used to examine the mierostructure and fracture surface of the specimens.The mechanical testing results demonstrated that the low cycle fatigue property of DZ40M significantly decreased with the partial reerystallization.Fatigue cracks initiate near the carbides and the grain boundaries with slip-bands.Both the fatigue crack initiation and propagation can be accelerated with the occurrences of recrystallized grain boundaries.

  8. Impact of direct-to-consumer advertising (DTCA) on patient health-related behaviors and issues.

    Science.gov (United States)

    Polen, Hyla H; Khanfar, Nile M; Clauson, Kevin A

    2009-01-01

    The pharmaceutical industry spends billions of dollars annually on direct-to-consumer advertising (DTCA). Patient perspectives on the impact of televised DTCA on health-related behaviors and issues were assessed by means of a 68-question survey. 58.6% of respondents believed that DTCA allowed consumers to have a more active role in managing their health. However, 27.6% felt DTCA caused confusion, and an alarming 17.8% of respondents stopped taking their medication because of concerns about serious side effects mentioned in DTCA. Overall, participants believed DTCA plays a useful role in health self-management; however, a considerable percentage thought that the cost outweighs the benefits.

  9. Factors Related to Rejection of Care and Behaviors Directed towards Others: A Longitudinal Study in Nursing Home Residents with Dementia

    Directory of Open Access Journals (Sweden)

    Francisca Galindo-Garre

    2015-04-01

    Full Text Available Aims: The aim of this study was to analyze factors related to rejection of care and behaviors directed towards others in nursing home residents with dementia. Methods: The relationship of lack of understanding, depression, psychosis and pain with rejection of care and behaviors directed towards others was explored using four assessments from the Minimum Data Set (MDS within a period of 15 months on 1,101 residents with dementia in Dutch nursing homes. Presence of depressive symptoms was ascertained using a validated MDS scale, and presence of lack of understanding, rejection of care, psychosis and pain through the individual MDS items. A structural equation modeling approach and latent growth models were used to investigate the longitudinal relationship between changes in rejection of care and physical or verbal behaviors directed towards others, and changes in lack of understanding, pain, depression and psychotic symptoms. Results: Changes in lack of understanding predicted changes in rejection of care, and there was also a relationship between changes in depression and rejection of care. Changes of behaviors directed towards others were related to changes in lack of understanding and depression. Pain and behaviors directed towards others were unrelated, and psychosis was rather stable throughout. A mediation model suggested that the relationship of lack of understanding with behaviors directed towards others was mediated by rejection of care. Conclusion: These results indicate that lack of understanding and depression are important factors in development of rejection of care and behaviors directed towards others. The relationship between lack of understanding and behaviors directed towards others is mediated by rejection of care. Improvement in communication between residents and caregivers, and perhaps also effective treatment of depression may prevent or ameliorate these behaviors directed towards others.

  10. Applying the model of Goal-Directed Behavior, including descriptive norms, to physical activity intentions: A contribution to improving the Theory of Planned Behavior

    Science.gov (United States)

    The theory of planned behavior (TPB) has received its fair share of criticism lately, including calls for it to retire. We contributed to improving the theory by testing extensions such as the model of goal-directed behavior (MGDB, which adds desire and anticipated positive and negative emotions) ap...

  11. Asymmetric-Structure Analysis of Carbon and Energy Markets

    Science.gov (United States)

    Xu, Wei; Cao, Guangxi

    2016-02-01

    This study aimed to investigate the asymmetric structure between the carbon and energy markets from two aspects of different trends (up or down) and volatility-transmission direction using asymmetric detrended cross-correlation analysis (DCCA) cross-correlation coefficient test, multifractal asymmetric DCCA (MF-ADCCA) method, asymmetric volatility-constrained correlation metric and time rate of information-flow approach. We sampled 1283 observations from January 2008 to December 2012 among pairs of carbon and energy markets for analysis. Empirical results show that the (1) asymmetric characteristic from the cross-correlation between carbon and returns in the energy markets is significant, (2) asymmetric cross-correlation between carbon and energy market price returns is persistent and multifractral and (3) volatility of the base assets of energy market returns is more influential to the base asset of the carbon market than that of the energy market.

  12. Asymmetric liquid wetting and spreading on surfaces with slanted micro-pillar arrays

    KAUST Repository

    Yang, Xiaoming

    2013-01-01

    Uni-directional liquid spreading on asymmetric silicone-fabricated nanostructured surfaces has recently been reported. In this work, uniformly deflected polydimethylsiloxane (PDMS) micro-pillars covered with silver films were fabricated. Asymmetric liquid wetting and spreading behaviors in a preferential direction were observed on the slanted micro-pillar surfaces and a micro-scale thin liquid film advancing ahead of the bulk liquid droplet was clearly observed by high-speed video imaging. It is found that the slanted micro-pillar array is able to promote or inhibit the propagation of this thin liquid film in different directions by the asymmetric capillary force. The spreading behavior of the bulk liquid was guided and finally controlled by this micro-scale liquid film. Different spreading regimes are defined by the relationship between the liquid intrinsic contact angle and the critical angles, which were determined by the pillar height, pillar deflection angle and inter-pillar spacing. © The Royal Society of Chemistry 2013.

  13. Internally generated sequences in learning and executing goal-directed behavior.

    Science.gov (United States)

    Pezzulo, Giovanni; van der Meer, Matthijs A A; Lansink, Carien S; Pennartz, Cyriel M A

    2014-12-01

    A network of brain structures including hippocampus (HC), prefrontal cortex, and striatum controls goal-directed behavior and decision making. However, the neural mechanisms underlying these functions are unknown. Here, we review the role of 'internally generated sequences': structured, multi-neuron firing patterns in the network that are not confined to signaling the current state or location of an agent, but are generated on the basis of internal brain dynamics. Neurophysiological studies suggest that such sequences fulfill functions in memory consolidation, augmentation of representations, internal simulation, and recombination of acquired information. Using computational modeling, we propose that internally generated sequences may be productively considered a component of goal-directed decision systems, implementing a sampling-based inference engine that optimizes goal acquisition at multiple timescales of on-line choice, action control, and learning.

  14. Uniaxial compressive behavior of micro-pillars of dental enamel characterized in multiple directions.

    Science.gov (United States)

    Yilmaz, Ezgi D; Jelitto, Hans; Schneider, Gerold A

    2015-04-01

    In this work, the compressive elastic modulus and failure strength values of bovine enamel at the first hierarchical level formed by hydroxyapatite (HA) nanofibers and organic matter are identified in longitudinal, transverse and oblique direction with the uniaxial micro-compression method. The elastic modulus values (∼70 GPa) measured here are within the range of results reported in the literature but these values were found surprisingly uniform in all orientations as opposed to the previous nanoindentation findings revealing anisotropic elastic properties in enamel. Failure strengths were recorded up to ∼1.7 GPa and different failure modes (such as shear, microbuckling, fiber fracture) governed by the orientation of the HA nanofibers were visualized. Structural irregularities leading to mineral contacts between the nanofibers are postulated as the main reason for the high compressive strength and direction-independent elastic behavior on enamels first hierarchical level. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Asymmetric Synthesis of (+)-(11 R,12S)-Mefloquine Hydrochloride

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The asymmetric synthesis of (+)-(11R,12S)-mefloquine hydrochloride, an antimalarial drug, was accomplished from commercially available 2-trifluoromethylaniline, ethyl 4,4,4-trifluoroacetoacetate and cyclopentanone in 7 steps with a 14% overall yield. The key steps were proline-catalyzed asymmetric direct aldol reaction and Beck-mann rearrangement. The absolute configuration was assigned by a Mosher's method.

  16. Behavioral deficits and axonal injury persistence after rotational head injury are direction dependent.

    Science.gov (United States)

    Sullivan, Sarah; Friess, Stuart H; Ralston, Jill; Smith, Colin; Propert, Kathleen J; Rapp, Paul E; Margulies, Susan S

    2013-04-01

    Pigs continue to grow in importance as a tool in neuroscience. However, behavioral tests that have been validated in the rodent model do not translate well to pigs because of their very different responses to behavioral stimuli. We refined metrics for assessing porcine open field behavior to detect a wide spectrum of clinically relevant behaviors in the piglet post-traumatic brain injury (TBI). Female neonatal piglets underwent a rapid non-impact head rotation in the sagittal plane (n=8 evaluable) or were instrumented shams (n=7 evaluable). Open field testing was conducted 1 day prior to injury (day -1) in order to establish an individual baseline for analysis, and at days +1 and +4 after injury. Animals were then killed on day +6 after injury for neuropathological assessment of axonal injury. Injured piglets were less interested in interacting with environmental stimuli and had a lower activity level than did shams. These data were compared with previously published data for axial rotational injuries in neonatal piglets. Acute behavioral outcomes post-TBI showed a dependence on the rotational plane of the brain injury, with animals with sagittal injuries demonstrating a greater level of inactivity and less random usage of the open field space than those with axial injuries. The persistence of axonal injury is also dependent on the rotational plane, with sagittal rotations causing more prolonged injuries than axial rotations. These results are consistent with animal studies, finite element models, and studies of concussions in football, which have all demonstrated differences in injury severity depending upon the direction of head impact rotation.

  17. Control of apoptosis by asymmetric cell division.

    Directory of Open Access Journals (Sweden)

    Julia Hatzold

    2008-04-01

    Full Text Available Asymmetric cell division and apoptosis (programmed cell death are two fundamental processes that are important for the development and function of multicellular organisms. We have found that the processes of asymmetric cell division and apoptosis can be functionally linked. Specifically, we show that asymmetric cell division in the nematode Caenorhabditis elegans is mediated by a pathway involving three genes, dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail, that directly control the enzymatic machinery responsible for apoptosis. Interestingly, the MIDA1-like protein GlsA of the alga Volvox carteri, as well as the Snail-related proteins Snail, Escargot, and Worniu of Drosophila melanogaster, have previously been implicated in asymmetric cell division. Therefore, C. elegans dnj-11 MIDA1, ces-2 HLF, and ces-1 Snail may be components of a pathway involved in asymmetric cell division that is conserved throughout the plant and animal kingdoms. Furthermore, based on our results, we propose that this pathway directly controls the apoptotic fate in C. elegans, and possibly other animals as well.

  18. Superplastic behavior of silica nanowires obtained by direct patterning of silsesquioxane-based precursors

    Science.gov (United States)

    Yılmaz, Mustafa; Wollschläger, Nicole; Nasr Esfahani, Mohammad; Österle, Werner; Leblebici, Yusuf; Erdem Alaca, B.

    2017-03-01

    Silica nanowires spanning 10 μm-deep trenches are fabricated from different types of silsesquioxane-based precursors by direct e-beam patterning on silicon followed by release through deep reactive ion etching. Nanowire aspect ratios as large as 150 are achieved with a critical dimension of about 50 nm and nearly rectangular cross-sections. In situ bending tests are carried out inside a scanning electron microscope, where the etch depth of 10 μ {{m}} provides sufficient space for deformation. Silica NWs are indeed observed to exhibit superplastic behavior without fracture with deflections reaching the full etch depth, about two orders of magnitude larger than the nanowire thickness. A large-deformation elastic bending model is utilized for predicting the deviation from the elastic behavior. The results of forty different tests indicate a critical stress level of 0.1–0.4 GPa for the onset of plasticity. The study hints at the possibility of fabricating silica nanowires in a monolithic fashion through direct e-beam patterning of silsesquioxane-based resins. The fabrication technology is compatible with semiconductor manufacturing and provides silica nanowires with a very good structural integrity.

  19. Attitudes towards Social Networking and Sharing Behaviors among Consumers of Direct-to-Consumer Personal Genomics.

    Science.gov (United States)

    Lee, Sandra Soo-Jin; Vernez, Simone L; Ormond, K E; Granovetter, Mark

    2013-10-14

    Little is known about how consumers of direct-to-consumer personal genetic services share personal genetic risk information. In an age of ubiquitous online networking and rapid development of social networking tools, understanding how consumers share personal genetic risk assessments is critical in the development of appropriate and effective policies. This exploratory study investigates how consumers share personal genetic information and attitudes towards social networking behaviors. Adult participants aged 23 to 72 years old who purchased direct-to-consumer genetic testing from a personal genomics company were administered a web-based survey regarding their sharing activities and social networking behaviors related to their personal genetic test results. 80 participants completed the survey; of those, 45% shared results on Facebook and 50.9% reported meeting or reconnecting with more than 10 other individuals through the sharing of their personal genetic information. For help interpreting test results, 70.4% turned to Internet websites and online sources, compared to 22.7% who consulted their healthcare providers. Amongst participants, 51.8% reported that they believe the privacy of their personal genetic information would be breached in the future. Consumers actively utilize online social networking tools to help them share and interpret their personal genetic information. These findings suggest a need for careful consideration of policy recommendations in light of the current ambiguity of regulation and oversight of consumer initiated sharing activities.

  20. Attitudes towards Social Networking and Sharing Behaviors among Consumers of Direct-to-Consumer Personal Genomics

    Directory of Open Access Journals (Sweden)

    Mark Granovetter

    2013-10-01

    Full Text Available Little is known about how consumers of direct-to-consumer personal genetic services share personal genetic risk information. In an age of ubiquitous online networking and rapid development of social networking tools, understanding how consumers share personal genetic risk assessments is critical in the development of appropriate and effective policies. This exploratory study investigates how consumers share personal genetic information and attitudes towards social networking behaviors. Methods: Adult participants aged 23 to 72 years old who purchased direct-to-consumer genetic testing from a personal genomics company were administered a web-based survey regarding their sharing activities and social networking behaviors related to their personal genetic test results. Results: 80 participants completed the survey; of those, 45% shared results on Facebook and 50.9% reported meeting or reconnecting with more than 10 other individuals through the sharing of their personal genetic information. For help interpreting test results, 70.4% turned to Internet websites and online sources, compared to 22.7% who consulted their healthcare providers. Amongst participants, 51.8% reported that they believe the privacy of their personal genetic information would be breached in the future. Conclusion: Consumers actively utilize online social networking tools to help them share and interpret their personal genetic information. These findings suggest a need for careful consideration of policy recommendations in light of the current ambiguity of regulation and oversight of consumer initiated sharing activities.

  1. Interaction of motility, directional sensing, and polarity modules recreates the behaviors of chemotaxing cells.

    Directory of Open Access Journals (Sweden)

    Changji Shi

    Full Text Available Chemotaxis involves the coordinated action of separable but interrelated processes: motility, gradient sensing, and polarization. We have hypothesized that these are mediated by separate modules that account for these processes individually and that, when combined, recreate most of the behaviors of chemotactic cells. Here, we describe a mathematical model where the modules are implemented in terms of reaction-diffusion equations. Migration and the accompanying changes in cellular morphology are demonstrated in simulations using a mechanical model of the cell cortex implemented in the level set framework. The central module is an excitable network that accounts for random migration. The response to combinations of uniform stimuli and gradients is mediated by a local excitation, global inhibition module that biases the direction in which excitability is directed. A polarization module linked to the excitable network through the cytoskeleton allows unstimulated cells to move persistently and, for cells in gradients, to gradually acquire distinct sensitivity between front and back. Finally, by varying the strengths of various feedback loops in the model we obtain cellular behaviors that mirror those of genetically altered cell lines.

  2. Cold asymmetrical fermion superfluids

    Energy Technology Data Exchange (ETDEWEB)

    Caldas, Heron

    2003-12-19

    The recent experimental advances in cold atomic traps have induced a great amount of interest in fields from condensed matter to particle physics, including approaches and prospects from the theoretical point of view. In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Here we extend the analysis and verify that in fact, the mixed phase is the preferred ground state of an asymmetrical superfluid in various situations. We predict that the mixed phase can serve as a way of detecting superfluidity and estimating the magnitude of the gap parameter in asymmetrical fermionic systems.

  3. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  4. A Prefrontal-Hippocampal Comparator for Goal-Directed Behavior: The Intentional Self and Episodic Memory.

    Science.gov (United States)

    Numan, Robert

    2015-01-01

    The hypothesis of this article is that the interactions between the prefrontal cortex and the hippocampus play a critical role in the modulation of goal-directed self-action and the strengthening of episodic memories. We describe various theories that model a comparator function for the hippocampus, and then elaborate the empirical evidence that supports these theories. One theory which describes a prefrontal-hippocampal comparator for voluntary action is emphasized. Action plans are essential for successful goal-directed behavior, and are elaborated by the prefrontal cortex. When an action plan is initiated, the prefrontal cortex transmits an efference copy (or corollary discharge) to the hippocampus where it is stored as a working memory for the action plan (which includes the expected outcomes of the action plan). The hippocampus then serves as a response intention-response outcome working memory comparator. Hippocampal comparator function is enabled by the hippocampal theta rhythm allowing the hippocampus to compare expected action outcomes to actual action outcomes. If the expected and actual outcomes match, the hippocampus transmits a signal to prefrontal cortex which strengthens or consolidates the action plan. If a mismatch occurs, the hippocampus transmits an error signal to the prefrontal cortex which facilitates a reformulation of the action plan, fostering behavioral flexibility and memory updating. The corollary discharge provides the self-referential component to the episodic memory, affording the personal and subjective experience of what behavior was carried out, when it was carried out, and in what context (where) it occurred. Such a perspective can be applied to episodic memory in humans, and episodic-like memory in non-human animal species.

  5. A prefrontal-hippocampal comparator for goal-directed behavior: the intentional self and episodic memory

    Directory of Open Access Journals (Sweden)

    Robert eNuman

    2015-11-01

    Full Text Available AbstractThe hypothesis of this article is that the interactions between the prefrontal cortex and the hippocampus play a critical role in the modulation of goal-directed self-action and the strengthening of episodic memories. We describe various theories that model a comparator function for the hippocampus, and then elaborate the empirical evidence that supports these theories. One theory which describes a prefrontal-hippocampal comparator for voluntary action, is emphasized. Action plans are essential for successful goal-directed behavior, and are elaborated by the prefrontal cortex. When an action plan is initiated, the prefrontal cortex transmits an efference copy (or corollary discharge to the hippocampus where it is stored as a working memory for the action plan (which includes the expected outcomes of the action plan. The hippocampus then serves as a response intention-response outcome working memory comparator. Hippocampal comparator function is enabled by the hippocampal theta rhythm allowing the hippocampus to compare expected action outcomes to actual action outcomes. If the expected and actual outcomes match, the hippocampus transmits a signal to prefrontal cortex which strengthens or consolidates the action plan. If a mismatch occurs, the hippocampus transmits an error signal to the prefrontal cortex which facilitates a reformulation of the action plan, fostering behavioral flexibility. The corollary discharge provides the self-referential component to the episodic memory, affording the personal and subjective experience of what behavior was carried out, when it was carried out, and in what context (where it occurred. Such a perspective can be applied to episodic memory in humans, and episodic-like memory in subhuman animal species.

  6. Immiscible displacement of oil by water in a microchannel: Asymmetric flow behavior and nonlinear stability analysis of core-annular flow

    Science.gov (United States)

    Foroughi, Hooman; Abbasi, Alireza; Das, Kausik S.; Kawaji, Masahiro

    2012-02-01

    The immiscible displacement of oil by water in a circular microchannel was investigated. A fused silica microchannel with an inner diameter of 250 μm and a length of 7 cm was initially filled with a viscous silicone oil. Only water then was injected into the channel. We describe our flow observations based on the two-dimensional images captured in the middle of the channel. The water finger displaced the oil and left an oil film on the channel wall. While the oil was being displaced at the core, the flow resistance decreased, which resulted in increases in water flow rate and inertia. Eventually, the water finger reached the channel exit and formed a core-annular flow pattern. The wavelength of the waves formed at the oil-water interface also increased with the increase in inertia. The initially symmetric interfacial waves became asymmetric with time. Also, the water core shifted from the center of the channel and left a thinner oil film on one side of the microchannel. Under all flow rates tested in this study, as long as the water was continuously injected, the water core was stable and no breakup into droplets was observed. We also discuss the flow stability based on nonlinear and linear stability analyses performed on the core-annular flow. Compared to the linear analysis, which ignores the inertia effects, the nonlinear analysis, which includes the inertia effects, predicts longer interfacial wavelengths by a factor of (1)/(1-(ao)/(2)(Wew+Weo(ao2)/(1-ao2))) where Wew and Weo are the Weber numbers of the water and the oil phases, respectively, and ao is the unperturbed water core radius made dimensionless by the channel radius.

  7. Immiscible displacement of oil by water in a microchannel: asymmetric flow behavior and nonlinear stability analysis of core-annular flow.

    Science.gov (United States)

    Foroughi, Hooman; Abbasi, Alireza; Das, Kausik S; Kawaji, Masahiro

    2012-02-01

    The immiscible displacement of oil by water in a circular microchannel was investigated. A fused silica microchannel with an inner diameter of 250 μm and a length of 7 cm was initially filled with a viscous silicone oil. Only water then was injected into the channel. We describe our flow observations based on the two-dimensional images captured in the middle of the channel. The water finger displaced the oil and left an oil film on the channel wall. While the oil was being displaced at the core, the flow resistance decreased, which resulted in increases in water flow rate and inertia. Eventually, the water finger reached the channel exit and formed a core-annular flow pattern. The wavelength of the waves formed at the oil-water interface also increased with the increase in inertia. The initially symmetric interfacial waves became asymmetric with time. Also, the water core shifted from the center of the channel and left a thinner oil film on one side of the microchannel. Under all flow rates tested in this study, as long as the water was continuously injected, the water core was stable and no breakup into droplets was observed. We also discuss the flow stability based on nonlinear and linear stability analyses performed on the core-annular flow. Compared to the linear analysis, which ignores the inertia effects, the nonlinear analysis, which includes the inertia effects, predicts longer interfacial wavelengths by a factor of 1/sqrt[1-a(o)/2(We(w) + We(o)a(o)(2)/1-a(o)(2))] where We(w) and We(o) are the Weber numbers of the water and the oil phases, respectively, and a(o) is the unperturbed water core radius made dimensionless by the channel radius.

  8. Asymmetric gear rectifies random robot motion

    Science.gov (United States)

    Li, He; Zhang, H. P.

    2013-06-01

    We experimentally study the dynamics of centimetric robots and their interactions with rotary gears through inelastic collisions. Under the impacts of self-propelled robots, a gear with symmetric teeth diffuses with no preferred direction of motion. An asymmetric gear, however, rectifies random motion of nearby robots which, in return, exert a torque on the gear and drive it into unidirectional motion. Rectification efficiency increases with the degree of gear asymmetry. Our work demonstrates that asymmetric environments can be used to rectify and extract energy from random motion of macroscopic self-propelled particles.

  9. Turning pain into cues for goal-directed behavior : Implementation intentions reduce escape-avoidance behavior on a painful task

    NARCIS (Netherlands)

    Karsdorp, P.A.; Geenen, R.; Kroese, F.M.; Vlaeyen, J.W.S.

    2016-01-01

    Pain automatically elicits escape-avoidance behavior to avert bodily harm. In patients with chronic pain, long-term escape-avoidance behavior may increase the risk of chronic disability. The aim of the presents study was to examine whether implementation intentions reduce escape-avoidance behavior d

  10. Direct electrochemistry behavior of Cytochrome c on silicon dioxide nanoparticles-modified electrode

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A newfangled direct electrochemistry behavior of Cytochrome c (Cyt c) was found on glassy carbon (GC) electrode modified with the silicon dioxide (SiO2) nanoparticles by physical adsorption. A pair of stable and well-defined redox peaks of Cyt c′ quasi-reversible electrochemical reaction were obtained with a heterogeneous electron transfer rate constant of 1.66×10-3 cm/s and a formal potential of 0.069 V (vs. Ag/AgCl) (0.263 V versus NHE) in 0.1 mol/L pH 6.8 PBS. Both the size and the amount of SiO2 nanoparticles could influence the electron transfer between Cyt c and the electrode. Electrostatic interaction which is between the negative nanoparticle surface and positively charged amino acid residues on the Cyt c surface is of importance for the stability and reproducibility toward the direct electron transfer of Cyt c. It is suggested that the modification of SiO2 nanoparticles proposes a novel approach to realize the direct electrochemistry of proteins.

  11. Barbed congruence of the asymmetric chi calculus

    Institute of Scientific and Technical Information of China (English)

    DONG Xiao-ju; FU Yu-xi

    2006-01-01

    The chi calculus is a model of mobile processes. It has evolved from the pi-calculus with motivations from simplification and communication-as-cut-elimination. This paper studies the chi calculus in the framework incorporating asymmetric communication. The major feature of the calculus is the identification of two actions:x/x and τ. The investigation on the barbed bisimilarity shows how the property affects the observational theory.Based on the definition of the barbed bisimilarity, the simulation properties of the barbed bisimilarity are studied. It shows that the algebraic properties of the barbed bisimilarity have changed greatly compared with the chi calculus. Although the definition of the barbed bisimilarity is very simple, the property of closeness under contexts makes it difficult to understand the barbed bisimilarity directly. Therefore an open style definition of the barbed bisimilarity is given, which is a context free description of barbed bisimilarity. Its definition is complex,but it is a well-behaved relation for it coincides with the barbed bisimilarity. It also helps to build an axiomatization system for the barbed congruence. Besides the axioms for the strong barbed bisimilarity, the paper proposes a new tau law and four new update laws for the barbed congruence. Both the operational and algebraic properties of the enriched calculus improve the understanding of the bisimulation behaviors of the model.

  12. Asymmetrical international attitudes

    NARCIS (Netherlands)

    Van Oudenhoven, JP; Askevis-Leherpeux, F; Hannover, B; Jaarsma, R; Dardenne, B

    2002-01-01

    In general, attitudes towards nations have a fair amount of reciprocity: nations either like each other are relatively indifferent to each other or dislike each other Sometimes, however international attitudes are asymmetrical. In this study, we use social identity theory in order to explain asymmet

  13. Asymmetric catalysis with helical polymers

    NARCIS (Netherlands)

    Megens, Rik P.; Roelfes, Gerard

    Inspired by nature, the use of helical biopolymer catalysts has emerged over the last years as a new approach to asymmetric catalysis. In this Concept article the various approaches and designs and their application in asymmetric catalysis will be discussed.

  14. Asymmetric catalysis with helical polymers

    NARCIS (Netherlands)

    Megens, Rik P.; Roelfes, Gerard

    2011-01-01

    Inspired by nature, the use of helical biopolymer catalysts has emerged over the last years as a new approach to asymmetric catalysis. In this Concept article the various approaches and designs and their application in asymmetric catalysis will be discussed.

  15. Asymmetric reactions in continuous flow

    Directory of Open Access Journals (Sweden)

    Xiao Yin Mak

    2009-04-01

    Full Text Available An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.

  16. Migration-driven aggregation behaviors in job markets with direct foreign immigration

    Science.gov (United States)

    Sun, Ruoyan

    2014-09-01

    This Letter introduces a new set of rate equations describing migration-driven aggregation behaviors in job markets with direct foreign immigration. We divide the job market into two groups: native and immigrant. A reversible migration of jobs exists in both groups. The interaction between two groups creates a birth and death rate for the native job market. We find out that regardless of initial conditions or the rates, the total number of cities with either job markets decreases. This indicates a more concentrated job markets for both groups in the future. On the other hand, jobs available for immigrants increase over time but the ones for natives are uncertain. The native job markets can either expand or shrink or remain constant due to combined effects of birth and death rates. Finally, we test our analytical results with the population data of all counties in the US from 2000 to 2011.

  17. The hippocampal-striatal axis in learning, prediction and goal-directed behavior.

    Science.gov (United States)

    Pennartz, C M A; Ito, R; Verschure, P F M J; Battaglia, F P; Robbins, T W

    2011-10-01

    The hippocampal formation and striatum subserve declarative and procedural memory, respectively. However, experimental evidence suggests that the ventral striatum, as opposed to the dorsal striatum, does not lend itself to being part of either system. Instead, it may constitute a system integrating inputs from the amygdala, prefrontal cortex and hippocampus to generate motivational, outcome-predicting signals that invigorate goal-directed behaviors. Inspired by reinforcement learning models, we suggest an alternative scheme for computational functions of the striatum. Dorsal and ventral striatum are proposed to compute outcome predictions largely in parallel, using different types of information as input. The nature of the inputs to striatum is furthermore combinatorial, and the specificity of predictions transcends the level of scalar value signals, incorporating episodic information.

  18. DNA Origami: Folded DNA-Nanodevices That Can Direct and Interpret Cell Behavior.

    Science.gov (United States)

    Kearney, Cathal J; Lucas, Christopher R; O'Brien, Fergal J; Castro, Carlos E

    2016-07-01

    DNA origami is a DNA-based nanotechnology that utilizes programmed combinations of short complementary oligonucleotides to fold a large single strand of DNA into precise 2D and 3D shapes. The exquisite nanoscale shape control of this inherently biocompatible material is combined with the potential to spatially address the origami structures with diverse cargoes including drugs, antibodies, nucleic acid sequences, small molecules, and inorganic particles. This programmable flexibility enables the fabrication of precise nanoscale devices that have already shown great potential for biomedical applications such as: drug delivery, biosensing, and synthetic nanopore formation. Here, the advances in the DNA-origami field since its inception several years ago are reviewed with a focus on how these DNA-nanodevices can be designed to interact with cells to direct or probe their behavior.

  19. Differential engagement of the ventromedial prefrontal cortex by goal-directed and habitual behavior toward food pictures in humans

    NARCIS (Netherlands)

    de Wit, S.; Corlett, P.R.; Aitken, M.R.; Dickinson, A.; Fletcher, P.C.

    2009-01-01

    According to dual-system accounts, instrumental learning is supported by both a goal-directed and a habitual system. Although behavioral control by the goal-directed system, through outcome-action associations, dominates with moderate training, stimulus-response associations are thought to form conc

  20. Apathy in Frontotemporal Degeneration: Neuroanatomical Evidence of Impaired Goal-Directed Behavior

    Directory of Open Access Journals (Sweden)

    Lauren eMassimo

    2015-11-01

    Full Text Available Background: Apathy, the major manifestation of impaired goal-directed behavior (GDB, is the most common neuropsychiatric syndrome associated with behavioral variant frontotemporal degeneration (bvFTD. The behavioral and biological mechanisms of apathy, however, are not well understood. We hypothesized that GDB has multiple components – including at least initiation, planning and motivation – and that GDB is supported by a network of multiple frontal brain regions. In this study, we examined this hypothesis by evaluating the selective breakdown of GDB in bvFTD, and relating these deficits to grey matter (GM atrophy and white matter (WM integrity. Methods: Eighteen apathetic bvFTD participants and 17 healthy controls completed the Philadelphia Apathy Computerized Test (PACT. This test quantifies each of three components of GDB hypothesized to contribute to apathy. We then used regression analyses to relate PACT scores to GM atrophy and reduced white matter (WM fractional anisotropy (FA in bvFTD. Results: Compared to controls, bvFTD participants demonstrated significant impairments in each of the three hypothesized components of GDB that contribute to apathy. Regression analyses related each component to disease in specific GM structures and associated WM tracts. Poor initiation thus was related to GM atrophy in anterior cingulate and reduced FA in the cingulum. Planning impairment was related to GM atrophy in dorsolateral prefrontal cortex and reduced FA in superior longitudinal fasciculus. Poor motivation was related to GM atrophy in orbitofrontal cortex and reduced FA in uncinate fasciculus. Conclusions: bvFTD patients have difficulty with initiation, planning and motivation components of GDB. These findings are consistent with the hypotheses that GDB encompasses at least three processes, that these are supported by a large-scale neural network within specific portions of the frontal lobe, and that degradation of any one of these prefrontal

  1. Direct observation of markovian behavior of the mechanical unfolding of individual proteins.

    Science.gov (United States)

    Cao, Yi; Kuske, Rachel; Li, Hongbin

    2008-07-01

    Single-molecule force-clamp spectroscopy is a valuable tool to analyze unfolding kinetics of proteins. Previous force-clamp spectroscopy experiments have demonstrated that the mechanical unfolding of ubiquitin deviates from the generally assumed Markovian behavior and involves the features of glassy dynamics. Here we use single molecule force-clamp spectroscopy to study the unfolding kinetics of a computationally designed fast-folding mutant of the small protein GB1, which shares a similar beta-grasp fold as ubiquitin. By treating the mechanical unfolding of polyproteins as the superposition of multiple identical Poisson processes, we developed a simple stochastic analysis approach to analyze the dwell time distribution of individual unfolding events in polyprotein unfolding trajectories. Our results unambiguously demonstrate that the mechanical unfolding of NuG2 fulfills all criteria of a memoryless Markovian process. This result, in contrast with the complex mechanical unfolding behaviors observed for ubiquitin, serves as a direct experimental demonstration of the Markovian behavior for the mechanical unfolding of a protein and reveals the complexity of the unfolding dynamics among structurally similar proteins. Furthermore, we extended our method into a robust and efficient pseudo-dwell-time analysis method, which allows one to make full use of all the unfolding events obtained in force-clamp experiments without categorizing the unfolding events. This method enabled us to measure the key parameters characterizing the mechanical unfolding energy landscape of NuG2 with improved precision. We anticipate that the methods demonstrated here will find broad applications in single-molecule force-clamp spectroscopy studies for a wide range of proteins.

  2. Migration-driven aggregation behaviors in job markets with direct foreign immigration

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ruoyan

    2014-09-05

    This Letter introduces a new set of rate equations describing migration-driven aggregation behaviors in job markets with direct foreign immigration. We divide the job market into two groups: native and immigrant. A reversible migration of jobs exists in both groups. The interaction between two groups creates a birth and death rate for the native job market. We find out that regardless of initial conditions or the rates, the total number of cities with either job markets decreases. This indicates a more concentrated job markets for both groups in the future. On the other hand, jobs available for immigrants increase over time but the ones for natives are uncertain. The native job markets can either expand or shrink or remain constant due to combined effects of birth and death rates. Finally, we test our analytical results with the population data of all counties in the US from 2000 to 2011. - Highlights: • A rate equation model describing the migration of job market is proposed. • We study the migration-driven aggregation behaviors over the longer term. • An illustrative example is given to check the effectiveness of the model.

  3. Excitons in asymmetric quantum wells

    Science.gov (United States)

    Grigoryev, P. S.; Kurdyubov, A. S.; Kuznetsova, M. S.; Ignatiev, I. V.; Efimov, Yu. P.; Eliseev, S. A.; Petrov, V. V.; Lovtcius, V. A.; Shapochkin, P. Yu.

    2016-09-01

    Resonance dielectric response of excitons is studied for the high-quality InGaAs/GaAs heterostructures with wide asymmetric quantum wells (QWs). To highlight effects of the QW asymmetry, we have grown and studied several heterostructures with nominally square QWs as well as with triangle-like QWs. Several quantum confined exciton states are experimentally observed as narrow exciton resonances. A standard approach for the phenomenological analysis of the profiles is generalized by introducing different phase shifts for the light waves reflected from the QWs at different exciton resonances. Good agreement of the phenomenological fit to the experimentally observed exciton spectra for high-quality structures allowed us to reliably obtain parameters of the exciton resonances: the exciton transition energies, the radiative broadenings, and the phase shifts. A direct numerical solution of the Schrödinger equation for the heavy-hole excitons in asymmetric QWs is used for microscopic modeling of the exciton resonances. Remarkable agreement with the experiment is achieved when the effect of indium segregation is taken into account. The segregation results in a modification of the potential profile, in particular, in an asymmetry of the nominally square QWs.

  4. Modulation of rotational behavior in healthy volunteers by cortisol administration

    NARCIS (Netherlands)

    Tops, M; Wijers, AA; Koch, T; Korf, J

    Asymmetrical turning behavior is an established indicator of asymmetrical dopaminergic activity and thought to be a manifestation of hemispatial neglect. We set out to find converging support for the hypothesis that cortisol modulates frontal dopaminergic asymmetrical activity, and hence

  5. Mapping Dimensionality and Directionality of Electronic Behavior in CeCoIn5: the Normal State

    Science.gov (United States)

    Gyenis, Andras; Feldman, Benjamin E.; Randeria, Mallika T.; Peterson, Gabriel A.; Aynajian, Pegor; Bauer, Eric D.; Yazdani, Ali

    Materials made from alternating layers of different constituents can exhibit dramatic variability in their electronic properties depending on which layer is probed. This is evident in the heavy fermion compound CeCoIn5, where scanning tunneling microscopy (STM) has revealed preferential coupling to either light or heavy electron states depending on the surface termination. Here we report STM measurements of CeCoIn5 cleaved perpendicular to its basal plane that clearly shows the quasi-two-dimensional nature of the electronic behavior on a single (100) surface. We observe atomic scale modulation of tunneling into the light and heavy electron bands in the c-axis direction, with no variation visible along the basal planes in the b-axis direction. In addition, conductance maps reveal preferential scattering along the two-dimensional basal planes. Our measurements highlight the reduced effective dimensionality of electronic states in CeCoIn5, and underscore the potential insight that can be gained by imaging layered materials perpendicular to their c-axis.

  6. Reduction of contact stresses using involute gears with asymmetric teeth

    OpenAIRE

    2015-01-01

    Asymmetrical involute gears have a different value of the operating pressure angle for right and left side of the gear. These teeth are suitable for one direction of rotation. Such teeth enable to change the length of the generating line. They enable to improve the value of reduced radii of curvature. Asymmetrical teeth allow reducing the values of Hertz's pressures, especially on the root of the teeth. Hertz pressures are directly related to the asymmetry.

  7. Effects of Physician-directed Pharmaceutical Promotion on Prescription Behaviors: Longitudinal Evidence.

    Science.gov (United States)

    Datta, Anusua; Dave, Dhaval

    2017-04-01

    Spending on prescription drugs (Rx) represents one of the fastest growing components of US healthcare spending and has coincided with an expansion of pharmaceutical promotional spending. Most (83%) of Rx promotion is directed at physicians in the form of visits by pharmaceutical representatives (known as detailing) and drug samples provided to physicians' offices. Such promotion has come under increased public scrutiny, with critics contending that physician-directed promotion may play a role in raising healthcare costs and may unduly affect physicians' prescribing habits towards more expensive, and possibly less cost-effective, drugs. In this study, we bring longitudinal evidence to bear upon the question of how detailing impacts physicians' prescribing behaviors. Specifically, we examine prescriptions and promotion for a particular drug class based on a nationally representative sample of 150,000 physicians spanning 24 months. The use of longitudinal physician-level data allows us to tackle some of the empirical concerns in the extant literature, virtually all of which have relied on aggregate national data. We estimate fixed-effects specifications that bypass stable unobserved physician-specific heterogeneity and address potential targeting bias. In addition, we also assess differential effects at both the extensive and intensive margins of prescribing behaviors and differential effects across physician-level and market-level characteristics, questions that have not been explored in prior work. The estimates suggest that detailing has a significant and positive effect on the number of new scripts written for the detailed drug, with an elasticity magnitude of 0.06. This effect is substantially smaller than those in the literature based on aggregate information, suggesting that most of the observed relationship between physician-directed promotion and drug sales is driven by selection bias. We find that detailing impacts selective brand-specific demand but does

  8. The time course for kinetic versus kinematic planning of goal-directed human motor behavior.

    Science.gov (United States)

    Vesia, Michael; Vander, Helena; Yan, Xiaogang; Sergio, Lauren E

    2005-01-01

    The present psychophysical study compares motor planning during goal-directed reaching movements and isometric spatial force generation. Our objective is to characterize the extent to which the motor system accounts for the biomechanical details of an impending reach. One issue that the nervous system must take into account when transforming a spatial sensory signal into an intrinsic pattern of joint torques is that of limb dynamics, including intersegmental dynamics and inertial anisotropy of the arm. These will act to displace the hand away from a straight path to an object. In theory, if the nervous system accounts for movement-related limb dynamics prior to its initial motor output, early force direction for a movement will differ from an isometric force to the same spatial target. Alternatively, biomechanical details of motor behavior may be implemented into the motor act following its initiation. Limb position and force output at the wrist were recorded while subjects displaced a cursor to targets viewed on a computer monitor. To generate isometric forces, a magnetic brake held a mechanical linkage supporting the arm in place. Subjects were cued to displace the cursor by using either isometric force or limb movement. On random trials, a movement was cued but an isometric force was unexpectedly required. Results show that there is not a significant directional difference in the initial force trajectory when planning a movement versus planning an isometric force. These findings suggest that the motor system may initially use a coarse approximation of movement-related limb dynamics, allowing for the refinement of the motor plan as the movement unfolds.

  9. Asymmetrical reinforcement and Wolbachia infection in Drosophila.

    Directory of Open Access Journals (Sweden)

    John Jaenike

    2006-10-01

    Full Text Available Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquinaria and males of D. recens result in high levels of offspring mortality, due to interspecific cytoplasmic incompatibility caused by Wolbachia infection of D. recens. Such hybrid inviability is not manifested in matings between D. recens females and D. subquinaria males. Here we ask whether the asymmetrical hybrid inviability is associated with a corresponding asymmetry in the level of reinforcement. The geographic ranges of D. recens and D. subquinaria were found to overlap across a broad belt of boreal forest in central Canada. Females of D. subquinaria from the zone of sympatry exhibit much stronger levels of discrimination against males of D. recens than do females from allopatric populations. In contrast, such reproductive character displacement is not evident in D. recens, consistent with the expected effects of unidirectional cytoplasmic incompatibility. Furthermore, there is substantial behavioral isolation within D. subquinaria, because females from populations sympatric with D. recens discriminate against allopatric conspecific males, whereas females from populations allopatric with D. recens show no discrimination against any conspecific males. Patterns of general genetic differentiation among populations are not consistent with patterns of behavioral discrimination, which suggests that the behavioral isolation within D. subquinaria results from selection against mating with Wolbachia-infected D. recens. Interspecific cytoplasmic incompatibility may contribute not only to post-mating isolation, an effect already widely recognized, but also to

  10. Evaluating Emotional and Biological Sensitivity to Maternal Behavior Among Self-Injuring and Depressed Adolescent Girls Using Nonlinear Dynamics

    DEFF Research Database (Denmark)

    Crowe, Sheila E; Butner, Jonathan E.; Wiltshire, Travis

    2017-01-01

    High sensitivity and reactivity to behaviors of family members characterize several forms of psychopathology, including self-inflicted injury (SII). We examined mother-daughter behavioral and psychophysiological reactivity during a conflict discussion using nonlinear dynamics to assess asymmetrical...... would not evoke mothers’ behavioral or physiological reactivity, and (c) control teens and mothers would be less reactive, with no dynamic associations in either direction. Convergent cross-mapping with dewdrop regression, which identifies directional associations, indicated that mothers’ behaviors...

  11. Directionality between Tolerance of Deviance and Deviant Behavior Is Age-Moderated in Chronically Stressed Youth

    Science.gov (United States)

    Ridenour, Ty A.; Caldwell, Linda L.; Coatsworth, J. Douglas; Gold, Melanie A.

    2011-01-01

    Problem behavior theory posits that tolerance of deviance is an antecedent to antisocial behavior and substance use. In contrast, cognitive dissonance theory implies that acceptability of a behavior may increase after experiencing the behavior. Using structural equation modeling, this investigation tested whether changes in tolerance of deviance…

  12. Neuronal activity in primate prefrontal cortex related to goal-directed behavior during auditory working memory tasks.

    Science.gov (United States)

    Huang, Ying; Brosch, Michael

    2016-06-01

    Prefrontal cortex (PFC) has been documented to play critical roles in goal-directed behaviors, like representing goal-relevant events and working memory (WM). However, neurophysiological evidence for such roles of PFC has been obtained mainly with visual tasks but rarely with auditory tasks. In the present study, we tested roles of PFC in auditory goal-directed behaviors by recording local field potentials in the auditory region of left ventrolateral PFC while a monkey performed auditory WM tasks. The tasks consisted of multiple events and required the monkey to change its mental states to achieve the reward. The events were auditory and visual stimuli, as well as specific actions. Mental states were engaging in the tasks and holding task-relevant information in auditory WM. We found that, although based on recordings from one hemisphere in one monkey only, PFC represented multiple events that were important for achieving reward, including auditory and visual stimuli like turning on and off an LED, as well as bar touch. The responses to auditory events depended on the tasks and on the context of the tasks. This provides support for the idea that neuronal representations in PFC are flexible and can be related to the behavioral meaning of stimuli. We also found that engaging in the tasks and holding information in auditory WM were associated with persistent changes of slow potentials, both of which are essential for auditory goal-directed behaviors. Our study, on a single hemisphere in a single monkey, reveals roles of PFC in auditory goal-directed behaviors similar to those in visual goal-directed behaviors, suggesting that functions of PFC in goal-directed behaviors are probably common across the auditory and visual modality. This article is part of a Special Issue entitled SI: Auditory working memory.

  13. Asymmetric extractions in orthodontics

    OpenAIRE

    Camilo Aquino Melgaço; Mônica Tirre de Souza Araújo

    2012-01-01

    INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portugue...

  14. Asymmetric information and economics

    Science.gov (United States)

    Frieden, B. Roy; Hawkins, Raymond J.

    2010-01-01

    We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.

  15. Broadband asymmetric acoustic transmission through an acoustic prism

    Science.gov (United States)

    Song, Ailing; Chen, Tianning; Wang, Xiaopeng; Xi, Yanhui

    2017-08-01

    Narrow bandwidth and complex structure are the main shortcomings of the existing asymmetric acoustic transmission devices. In this letter, a simple broadband asymmetric acoustic transmission device is proposed by using an acoustic prism filled with xenon gas. The sound pressure field distributions, the transmission spectra, and the prism angle effect are numerically investigated by using finite element method. The proposed device can always realize asymmetric acoustic transmission for the wave frequency larger than 480 Hz because the wave paths are not influenced by the wave frequencies. The asymmetric acoustic transmission is attributed to normal refraction and total reflection occur at different interfaces. Besides, relatively high transmission efficiency is realized due to the similar impedance between the acoustic prism and background. And the transmitted wave direction can be controlled freely by changing the prism angle. Our design provides a simple method to obtain broadband asymmetric acoustic transmission device and has potentials in many applications, such as noise control and medical ultrasound.

  16. Simulation of Chaos in Asymmetric Nonlinear Chua's Circuit

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-fei; QIAO Shu-tong; JIANG Jian-guo

    2008-01-01

    In order to describe practical chaotic systems exactly, we presented a simple modified Chua's circuit,which contains an asymmetric nonlinear resistive element. Mathematical analysis was made, and simulation study was performed by MATLAB. By varying the value of linear resistor in the circuit, rich variety dynamical behaviors were observed, such as DC equilibrium point, Hopf bifurcation, period-doubling bifurcation,single-scroll strange attractor, periodic windows, and asymmetric double-scroll strange attractor. The extreme sensitivity in the state trajectory with respect to the initial conditions was exhibited; the special characteristic of asymmetric nonlinear Chua's circuit was found also.

  17. Asymmetric coherent transmission for single particle diode and gyroscope

    CERN Document Server

    Yang, S; Sun, C P

    2009-01-01

    We study the single particle scattering process in a coherent multi-site system consisting of a tight-binding ring threaded by an Aharonov-Bohm flux and several attaching leads. The asymmetric behavior of scattering matrix is discovered analytically in the framework of both Bethe Ansatz and Green's function formalism. It is found that, under certain conditions, a three-site electronic system can behave analogous to a perfect semiconductor diode where current flows only in one direction. The general result is also valid for a neutral particle system since the effective magnetic flux may be implemented by a globe rotation. This observation means that the three-site system can serve as an orientation measuring gyroscope due to the approximate linear dependence of the current difference of two output leads on the rotational angular velocity.

  18. Asymmetric Evolutionary Games.

    Directory of Open Access Journals (Sweden)

    Alex McAvoy

    2015-08-01

    Full Text Available Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner's Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games.

  19. Asymmetric extractions in orthodontics

    Directory of Open Access Journals (Sweden)

    Camilo Aquino Melgaço

    2012-04-01

    Full Text Available INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portuguese and the EndNote 9 program was used for data base search in PubMed, Web of Science (WSc and LILACS. The selected articles were case reports, original articles and prospective or retrospective case-control studies concerning asymmetrical extractions of permanent teeth for the treatment of malocclusions. CONCLUSION: According to the literature reviewed asymmetric extractions can make some specific treatment mechanics easier. Cases finished with first permanent molars in Class II or III relationship in one or both sides seem not to cause esthetic or functional problems. However, diagnosis knowledge and mechanics control are essential for treatment success.

  20. Perseveration on a reversal-learning task correlates with rates of self-directed behavior in nonhuman primates.

    Science.gov (United States)

    Judge, Peter G; Evans, David W; Schroepfer, Kara K; Gross, Alyssa C

    2011-09-12

    In humans and several nonhuman animals, repetitive behavior is associated with deficits on executive function tasks involving response inhibition. We tested for this relationship in nonhuman primates by correlating rates of normative behavior to performance on a reversal-learning task in which animals were required to inhibit a previously learned rule. We focused on rates of self-directed behavior (scratch, autogroom, self touch and manipulation) because these responses are known indicators of arousal or anxiety in primates, however, we also examined rates of other categories of behavior (e.g., locomotion). Behavior rates were obtained from 14 animals representing three nonhuman primate species (Macaca silenus, Saimiri sciureus, Cebus apella) living in separate social groups. The same animals were tested on a reversal-learning task in which they were presented with a black and a grey square on a touch screen and were trained to touch the black square. Once animals learned to select the black square, reward contingencies were reversed and animals were rewarded for selecting the grey square. Performance on the reversal-learning task was positively correlated to self-directed behavior in that animals that exhibited higher rates of self-directed behavior required more trials to achieve reversal. Reversal learning was not correlated to rates of any other category of behavior. Results indicate that rates of behavior associated with anxiety and arousal provide an indicator of executive function in nonhuman primates. The relationship suggests continuity between nonhuman primates and humans in the link between executive functioning and repetitive behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Selective theta-synchronization of choice-relevant information subserves goal-directed behavior

    Directory of Open Access Journals (Sweden)

    Thilo eWomelsdorf

    2010-11-01

    Full Text Available Theta activity reflects a state of rhythmic modulation of excitability at the level of single neuron membranes, within local neuronal groups and between distant nodes of a neuronal network. A wealth of evidence has shown that during theta states distant neuronal groups synchronize, forming networks of spatially confined neuronal clusters at specific time periods during task performance. Here, we show that a functional commonality of networks engaging in theta rhythmic states is that they emerge around decision points, reflecting rhythmic synchronization of choice-relevant information. Decision points characterize a point in time shortly before a subject chooses to select one action over another, i.e. when automatic behavior is terminated and the organism reactivates multiple sources of information to evaluate the evidence for available choices. As such, decision processes require the coordinated retrieval of choice-relevant information including (i the retrieval of stimulus evaluations (stim.-reward associations and reward expectancies about future outcomes, (ii the retrieval of past and prospective memories (e.g. stim.-stim. associations, (iii the reactivation of contextual task rule representations (e.g. stim.-response mappings, along with (iv an ongoing assessment of sensory evidence. An increasing number of studies reveal that retrieval of these multiple types of information proceeds within few theta cycles through synchronized spiking activity across limbic, striatal and cortical processing nodes. The outlined evidence suggests that evolving spatially and temporally specific theta synchronization could serve as the critical correlate underlying the selection of a choice during goal-directed behavior.

  2. Goal-Directed Behavior and Instrumental Devaluation: A Neural System-Level Computational Model.

    Science.gov (United States)

    Mannella, Francesco; Mirolli, Marco; Baldassarre, Gianluca

    2016-01-01

    Devaluation is the key experimental paradigm used to demonstrate the presence of instrumental behaviors guided by goals in mammals. We propose a neural system-level computational model to address the question of which brain mechanisms allow the current value of rewards to control instrumental actions. The model pivots on and shows the computational soundness of the hypothesis for which the internal representation of instrumental manipulanda (e.g., levers) activate the representation of rewards (or "action-outcomes", e.g., foods) while attributing to them a value which depends on the current internal state of the animal (e.g., satiation for some but not all foods). The model also proposes an initial hypothesis of the integrated system of key brain components supporting this process and allowing the recalled outcomes to bias action selection: (a) the sub-system formed by the basolateral amygdala and insular cortex acquiring the manipulanda-outcomes associations and attributing the current value to the outcomes; (b) three basal ganglia-cortical loops selecting respectively goals, associative sensory representations, and actions; (c) the cortico-cortical and striato-nigro-striatal neural pathways supporting the selection, and selection learning, of actions based on habits and goals. The model reproduces and explains the results of several devaluation experiments carried out with control rats and rats with pre- and post-training lesions of the basolateral amygdala, the nucleus accumbens core, the prelimbic cortex, and the dorso-medial striatum. The results support the soundness of the hypotheses of the model and show its capacity to integrate, at the system-level, the operations of the key brain structures underlying devaluation. Based on its hypotheses and predictions, the model also represents an operational framework to support the design and analysis of new experiments on the motivational aspects of goal-directed behavior.

  3. Three dimensional force balance of asymmetric droplets

    Science.gov (United States)

    Kim, Yeseul; Lim, Su Jin; Cho, Kun; Weon, Byung Mook

    2016-11-01

    An equilibrium contact angle of a droplet is determined by a horizontal force balance among vapor, liquid, and solid, which is known as Young's law. Conventional wetting law is valid only for axis-symmetric droplets, whereas real droplets are often asymmetric. Here we show that three-dimensional geometry must be considered for a force balance for asymmetric droplets. By visualizing asymmetric droplets placed on a free-standing membrane in air with X-ray microscopy, we are able to identify that force balances in one side and in other side control pinning behaviors during evaporation of droplets. We find that X-ray microscopy is powerful for realizing the three-dimensional force balance, which would be essential in interpretation and manipulation of wetting, spreading, and drying dynamics for asymmetric droplets. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2016R1D1A1B01007133).

  4. Cooperative Mechanism of Supply Chain Under Asymmetric Information

    Institute of Scientific and Technical Information of China (English)

    郭敏; 王红卫; 瞿坦

    2003-01-01

    The cooperative mechanism is one main issue in the decentralized supply chain system, especially in an asymmetric information structure. We analyze the non-cooperative game behavior of a 2-echelon distribution supply chain, compare the results with the system optimal solution, and give the supplier dominated cooperative mechanisms. We also analyze the validity of our contract under the asymmetric retailers' holding cost information and give some useful conclusions.

  5. The oldest anatomically modern humans from far southeast Europe: direct dating, culture and behavior.

    Directory of Open Access Journals (Sweden)

    Sandrine Prat

    Full Text Available BACKGROUND: Anatomically Modern Humans (AMHs are known to have spread across Europe during the period coinciding with the Middle to Upper Paleolithic transition. Whereas their dispersal into Western Europe is relatively well established, evidence of an early settlement of Eastern Europe by modern humans are comparatively scarce. METHODOLOGY/PRINCIPAL FINDING: Based on a multidisciplinary approach for the study of human and faunal remains, we describe here the oldest AMH remains from the extreme southeast Europe, in conjunction with their associated cultural and paleoecological background. We applied taxonomy, paleoecology, and taphonomy combined with geomorphology, stratigraphy, archeology and radiocarbon dating. More than 160 human bone remains have been discovered. They originate from a well documented Upper Paleolithic archeological layer (Gravettian cultural tradition from the site of Buran-Kaya III located in Crimea (Ukraine. The combination of non-metric dental traits and the morphology of the occipital bones allow us to attribute the human remains to Anatomically Modern Humans. A set of human and faunal remains from this layer has been radiocarbon dated by Accelerator Mass Spectrometry. The direct-dating results of human bone establish a secure presence of AMHs at 31,900+240/-220 BP in this region. They are the oldest direct evidence of the presence of AMHs in a well documented archeological context. Based on taphonomical observations (cut marks and distribution of skeletal elements, they represent the oldest Upper Paleolithic modern humans from Eastern Europe, showing post-mortem treatment of the dead as well. CONCLUSION/SIGNIFICANCE: These findings are essential for the debate on the spread of modern humans in Europe during the Upper Paleolithic, as well as their cultural behaviors.

  6. The oldest anatomically modern humans from far southeast Europe: direct dating, culture and behavior.

    Science.gov (United States)

    Prat, Sandrine; Péan, Stéphane C; Crépin, Laurent; Drucker, Dorothée G; Puaud, Simon J; Valladas, Hélène; Lázničková-Galetová, Martina; van der Plicht, Johannes; Yanevich, Alexander

    2011-01-01

    Anatomically Modern Humans (AMHs) are known to have spread across Europe during the period coinciding with the Middle to Upper Paleolithic transition. Whereas their dispersal into Western Europe is relatively well established, evidence of an early settlement of Eastern Europe by modern humans are comparatively scarce. Based on a multidisciplinary approach for the study of human and faunal remains, we describe here the oldest AMH remains from the extreme southeast Europe, in conjunction with their associated cultural and paleoecological background. We applied taxonomy, paleoecology, and taphonomy combined with geomorphology, stratigraphy, archeology and radiocarbon dating. More than 160 human bone remains have been discovered. They originate from a well documented Upper Paleolithic archeological layer (Gravettian cultural tradition) from the site of Buran-Kaya III located in Crimea (Ukraine). The combination of non-metric dental traits and the morphology of the occipital bones allow us to attribute the human remains to Anatomically Modern Humans. A set of human and faunal remains from this layer has been radiocarbon dated by Accelerator Mass Spectrometry. The direct-dating results of human bone establish a secure presence of AMHs at 31,900+240/-220 BP in this region. They are the oldest direct evidence of the presence of AMHs in a well documented archeological context. Based on taphonomical observations (cut marks and distribution of skeletal elements), they represent the oldest Upper Paleolithic modern humans from Eastern Europe, showing post-mortem treatment of the dead as well. These findings are essential for the debate on the spread of modern humans in Europe during the Upper Paleolithic, as well as their cultural behaviors.

  7. Measuring Learning Styles with Questionnaires versus Direct Observation of Preferential Choice Behavior in Authentic Learning Situations: The Visualizer/Verbalizer Behavior Observation Scale (VV-BOS).

    Science.gov (United States)

    Leutner, Detlev; Plass, Jan L.

    1998-01-01

    Describes the development of the VV-BOS (Visualizer/Verbalizer Behavior Observation Scale), a computer-based instrument for direct observation of students' preferences for visual or verbal learning material. Results of a study with second-language learners indicated a high degree of reliability as an alternative to conventional questionnaires.…

  8. Behavioral pattern of a monopolar passive direct methanol fuel cell stack

    Science.gov (United States)

    Kim, Young-Jin; Bae, Byungchan; Scibioh, M. Aulice; Cho, EunAe; Ha, Heung Yong

    A passive, air-breathing, monopolar, liquid feed direct methanol fuel cell (DMFC) stack consisting of six unit cells with no external pump, fan or auxiliary devices to feed the reactants has been designed and fabricated for its possible employment as a portable power source. The configurations of the stack of monopolar passive feed DMFCs are different from those of bipolar active feed DMFCs and therefore its operational characteristics completely vary from the active ones. Our present investigation primarily focuses on understanding the unique behavioral patterns of monopolar stack under the influence of certain operating conditions, such as temperature, methanol concentration and reactants feeding methods. With passive reactants supply, the temperature of the stack and open circuit voltage (OCV) undergo changes over time due to a decrease in concentration of methanol in the reservoir as the reaction proceeds. Variations in performance and temperature of the stack are mainly influenced by the concentration of methanol. Continuous operation of the passive stack is influenced by the supply of methanol rather than air supply or water accumulation at the cathode. The monopolar stack made up of six unit cells exhibits a total power of 1000 mW (37 mW cm -2) with 4 M methanol under ambient conditions.

  9. Transcranial direct current stimulation in Parkinson's disease: Neurophysiological mechanisms and behavioral effects.

    Science.gov (United States)

    Broeder, Sanne; Nackaerts, Evelien; Heremans, Elke; Vervoort, Griet; Meesen, Raf; Verheyden, Geert; Nieuwboer, Alice

    2015-10-01

    Recent research has highlighted the potential of transcranial direct current stimulation (tDCS) to complement rehabilitation effects in the elderly and in patients with neurological diseases, including Parkinson's disease (PD). TDCS can modulate cortical excitability and enhance neurophysiological mechanisms that compensate for impaired learning in PD. The objective of this systematic review is to provide an overview of the effects of tDCS on neurophysiological and behavioral outcome measures in PD patients, both as a stand-alone and as an adjunctive therapy. We systematically reviewed the literature published throughout the last 10 years. Ten studies were included, most of which were sham controlled. Results confirmed that tDCS applied to the motor cortex had significant results on motor function and to a lesser extent on cognitive tests. However, the physiological mechanism underlying the long-term effects of tDCS on cortical excitability in the PD brain are still unclear and need to be clarified in order to apply this technique optimally to a wider population in the different disease stages and with different medication profiles.

  10. Emotion and goal-directed behavior: ERP evidence on cognitive and emotional conflict.

    Science.gov (United States)

    Zinchenko, Artyom; Kanske, Philipp; Obermeier, Christian; Schröger, Erich; Kotz, Sonja A

    2015-11-01

    Cognitive control supports goal-directed behavior by resolving conflict among opposing action tendencies. Emotion can trigger cognitive control processes, thus speeding up conflict processing when the target dimension of stimuli is emotional. However, it is unclear what role emotionality of the target dimension plays in the processing of emotional conflict (e.g. in irony). In two EEG experiments, we compared the influence of emotional valence of the target (emotional, neutral) in cognitive and emotional conflict processing. To maximally approximate real-life communication, we used audiovisual stimuli. Participants either categorized spoken vowels (cognitive conflict) or their emotional valence (emotional conflict), while visual information was congruent or incongruent. Emotional target dimension facilitated both cognitive and emotional conflict processing, as shown in a reduced reaction time conflict effect. In contrast, the N100 in the event-related potentials showed a conflict-specific reversal: the conflict effect was larger for emotional compared with neutral trials in cognitive conflict and smaller in emotional conflict. Additionally, domain-general conflict effects were observed in the P200 and N200 responses. The current findings confirm that emotions have a strong influence on cognitive and emotional conflict processing. They also highlight the complexity and heterogeneity of the interaction of emotion with different types of conflict. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  11. MicroRNA-198 inhibited tumorous behaviors of human osteosarcoma through directly targeting ROCK1.

    Science.gov (United States)

    Zhang, Shilian; Zhao, Yuehua; Wang, Lijie

    2016-04-08

    Osteosarcoma is an aggressive primary sarcoma of bone and occurs mainly in adolescents and young adults. The prognosis of OS remains poor, and most of them will die due to local relapse or metastases. The discovery of microRNAs provides a new possibility for the early diagnosis and treatment of OS. Thus, the aim of this study was to explore the expression and functions of microRNA-198 (miR-198) in osteosarcoma. The expression levels of miR-198 were determined by qRT-PCR in osteosarcoma tissues and cell lines. Cell proliferation assays, migration and invasion assays were adopted to investigate the effects of miR-198 on tumorous behaviors of osteosarcoma cells. The results showed that miR-198 expression levels were lower in osteosarcoma tissues and cell lines. In addition, low miR-198 expression levels were correlated with TNM stage and distant metastasis. After miR-198 mimics transfection, cell proliferation, migration and invasion were significantly suppressed in the osteosarcoma cells. Furthermore, ROCK1 was identified as a novel direct target of miR-198 in osteosarcoma. These findings suggested that miR-198 may act not only as a novel prognostic marker, but also as a potential target for molecular therapy of osteosarcoma.

  12. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  13. MicroRNA-198 inhibited tumorous behaviors of human osteosarcoma through directly targeting ROCK1

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shilian, E-mail: shilian_zhang@126.com; Zhao, Yuehua; Wang, Lijie

    2016-04-08

    Osteosarcoma is an aggressive primary sarcoma of bone and occurs mainly in adolescents and young adults. The prognosis of OS remains poor, and most of them will die due to local relapse or metastases. The discovery of microRNAs provides a new possibility for the early diagnosis and treatment of OS. Thus, the aim of this study was to explore the expression and functions of microRNA-198 (miR-198) in osteosarcoma. The expression levels of miR-198 were determined by qRT-PCR in osteosarcoma tissues and cell lines. Cell proliferation assays, migration and invasion assays were adopted to investigate the effects of miR-198 on tumorous behaviors of osteosarcoma cells. The results showed that miR-198 expression levels were lower in osteosarcoma tissues and cell lines. In addition, low miR-198 expression levels were correlated with TNM stage and distant metastasis. After miR-198 mimics transfection, cell proliferation, migration and invasion were significantly suppressed in the osteosarcoma cells. Furthermore, ROCK1 was identified as a novel direct target of miR-198 in osteosarcoma. These findings suggested that miR-198 may act not only as a novel prognostic marker, but also as a potential target for molecular therapy of osteosarcoma.

  14. Cell-Type-Specific Activity in Prefrontal Cortex during Goal-Directed Behavior.

    Science.gov (United States)

    Pinto, Lucas; Dan, Yang

    2015-07-15

    The prefrontal cortex (PFC) plays a key role in controlling goal-directed behavior. Although a variety of task-related signals have been observed in the PFC, whether they are differentially encoded by various cell types remains unclear. Here we performed cellular-resolution microendoscopic Ca(2+) imaging from genetically defined cell types in the dorsomedial PFC of mice performing a PFC-dependent sensory discrimination task. We found that inhibitory interneurons of the same subtype were similar to each other, but different subtypes preferentially signaled different task-related events: somatostatin-positive neurons primarily signaled motor action (licking), vasoactive intestinal peptide-positive neurons responded strongly to action outcomes, whereas parvalbumin-positive neurons were less selective, responding to sensory cues, motor action, and trial outcomes. Compared to each interneuron subtype, pyramidal neurons showed much greater functional heterogeneity, and their responses varied across cortical layers. Such cell-type and laminar differences in neuronal functional properties may be crucial for local computation within the PFC microcircuit.

  15. Family Violence and Children's Behavior Problems: Independent Contributions of Intimate Partner and Child-Directed Physical Aggression.

    Science.gov (United States)

    Gustafsson, Hanna C; Barnett, Melissa A; Towe-Goodman, Nissa R; Mills-Koonce, W Roger; Cox, Martha J

    2014-10-01

    Using data from a diverse sample of 581 families living in predominantly low-income, rural communities, the current study sought to investigate the longitudinal associations among father-perpetrated intimate partner violence (IPV) and child-directed physical aggression perpetrated by the mother. The unique contributions of each of these types of family violence on children's behavioral problems at school entry were also examined. Results confirm bidirectional associations between father-perpetrated IPV and maternal physical aggression directed toward the child, and indicate that both types of physical aggression contribute to child behavior problems at school entry.

  16. Designing Serious Video Games for Health Behavior Change: Current Status and Future Directions

    OpenAIRE

    Thompson, Debbe

    2012-01-01

    Serious video games for health are designed to entertain while changing a specific health behavior. This article identifies behavioral principles that can guide the development of serious video games focused on changing a variety of health behaviors, including those attempting to decrease risk of obesity and type 2 diabetes. Guidelines discussed include how to develop video games that provide a solid foundation for behavior change by enhancing a player’s knowledge and skill, ways in which per...

  17. Behavioral Deficits and Axonal Injury Persistence after Rotational Head Injury Are Direction Dependent

    OpenAIRE

    Sullivan, Sarah; Friess, Stuart H.; Ralston, Jill; Smith, Colin; Propert, Kathleen J.; Rapp, Paul E.; Margulies, Susan S.

    2013-01-01

    Pigs continue to grow in importance as a tool in neuroscience. However, behavioral tests that have been validated in the rodent model do not translate well to pigs because of their very different responses to behavioral stimuli. We refined metrics for assessing porcine open field behavior to detect a wide spectrum of clinically relevant behaviors in the piglet post-traumatic brain injury (TBI). Female neonatal piglets underwent a rapid non-impact head rotation in the sagittal plane (n=8 evalu...

  18. Evidence for habitual and goal-directed behavior following devaluation of cocaine: a multifaceted interpretation of relapse.

    Directory of Open Access Journals (Sweden)

    David H Root

    Full Text Available BACKGROUND: Cocaine addiction is characterized as a chronically relapsing disorder. It is believed that cues present during self-administration become learned and increase the probability that relapse will occur when they are confronted during abstinence. However, the way in which relapse-inducing cues are interpreted by the user has remained elusive. Recent theories of addiction posit that relapse-inducing cues cause relapse habitually or automatically, bypassing processing information related to the consequences of relapse. Alternatively, other theories hypothesize that relapse-inducing cues produce an expectation of the drug's consequences, designated as goal-directed relapse. Discrete discriminative stimuli signaling the availability of cocaine produce robust cue-induced responding after thirty days of abstinence. However, it is not known whether cue-induced responding is a goal-directed action or habit. METHODOLOGY/PRINCIPAL FINDINGS: We tested whether cue-induced responding is a goal-directed action or habit by explicitly pairing or unpairing cocaine with LiCl-induced sickness (n = 7/group, thereby decreasing or not altering the value of cocaine, respectively. Following thirty days of abstinence, no difference in responding between groups was found when animals were reintroduced to the self-administration environment alone, indicating habitual behavior. However, upon discriminative stimulus presentations, cocaine-sickness paired animals exhibited decreased cue-induced responding relative to unpaired controls, indicating goal-directed behavior. In spite of the difference between groups revealed during abstinent testing, no differences were found between groups when animals were under the influence of cocaine. CONCLUSIONS/SIGNIFICANCE: Unexpectedly, both habitual and goal-directed responding occurred during abstinent testing. Furthermore, habitual or goal-directed responding may have been induced by cues that differed in their correlation

  19. Designing serious video games for health behavior change: Current status and future directions

    Science.gov (United States)

    Serious video games for health are designed to entertain while changing a specific health behavior. This article identifies behavioral principles that can guide the development of serious video games focused on changing a variety of health behaviors, including those attempting to decrease risk of o...

  20. Microstructural evolution and corrosion behavior of directionally solidified FeCoNiCrAl high entropy alloy

    OpenAIRE

    2011-01-01

    The FeCoNiCrAl alloys have many potential applications in the fields of structural materials, but few attempts were made to characterize the directional solidification of high entropy alloys. In the present research, the microstructure and corrosion behavior of FeCoNiCrAl high entropy alloy have been investigated under directional solidification. The results show that with increasing solidification rate, the interface morphology of the alloy evolves from planar to cellular and dendritic. The ...

  1. Asymmetric synthesis v.4

    CERN Document Server

    Morrison, James

    1984-01-01

    Asymmetric Synthesis, Volume 4: The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers describes the practical methods of obtaining chiral fragments. Divided into five chapters, this book specifically examines initial chiral transmission and extension. The opening chapter describes the so-called chiral carbon pool, the readily available chiral carbon fragments used as building blocks in synthesis. This chapter also provides a list of 375 chiral building blocks, along with their commercial sources, approximate prices, and methods of synthesis. Schemes involving

  2. Behavioral Self-Regulation and Weight-Related Behaviors in Inner-City Adolescents: A Model of Direct and Indirect Effects.

    Science.gov (United States)

    Isasi, Carmen R; Wills, Thomas A

    2011-08-01

    BACKGROUND: This study examined the association of two distinct self-regulation constructs, effortful control and dysregulation, with weight-related behaviors in adolescents and tested whether these effects were mediated by self-efficacy variables. METHODS: A school-based survey was conducted with 1771 adolescents from 11 public schools in the Bronx, New York. Self-regulation was assessed by multiple indicators and defined as two latent constructs. Dependent variables included fruit/vegetable intake, intake of snack/junk food, frequency of physical activity, and time spent in sedentary behaviors. Structural equation modeling examined the relation of effortful control and dysregulation to lifestyle behaviors, with self-efficacy variables as possible mediators. RESULTS: Study results showed that effortful control had a positive indirect effect on fruit and vegetable intake, mediated by self-efficacy, as well as a direct effect. Effortful control also had a positive indirect effect on physical activity, mediated by self-efficacy. Dysregulation had direct effects on intake of junk food/snacks and time spent in sedentary behaviors. CONCLUSIONS: These findings indicate that self-regulation characteristics are related to diet and physical activity and that some of these effects are mediated by self-efficacy. Different effects were noted for the two domains of self-regulation. Prevention researchers should consider including self-regulation processes in programs to improve health behaviors in adolescents.

  3. Influence of dominance rank and affiliation relationships on self-directed behavior in female Tibetan macaques (Macaca thibetana).

    Science.gov (United States)

    Zhang, Qi-Xin; Li, Jin-Hua; Xia, Dong-Po; Zhu, Yong; Wang, Xi; Zhang, Dao

    2014-05-01

    Self-directed behavior (SDB) is characterized as an indicator of anxiety, frustration and stress in nonhuman primates. In this study, we collected self-directed behavior data from one group of free-ranging Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China (September 2012-May 2013) using a combination of behavioral sampling methods including focal animal sampling, behavioral sampling, continuous sampling and instantaneous sampling. Our results showed that females engaged in significantly higher rates of self-directed behavior when they were in proximity to dominant individuals compared to subordinate ones. Conflict losers significantly increased their SDB rates after agonistic episodes, indicating that SDB might also serve as an index of anxiety in M. thibetana. We further found that females significantly increased their SDB rates when focal individual was proximity to weakly affiliation relationship higher rank members than to strongly affiliation relationship higher rank members. If conflicts were not reconciled, the postconflict SDB rates of losers were higher when they stayed with strongly affiliation opponents; if conflicts were reconciled, victims of strongly affiliation relationships opponents engaged in more SDB rates before reconciliation than after reconciliation, while victims of moderately affiliation relationships opponents did not engaged in more SDB rates before reconciliation than after reconciliation. We conclude that both of dominance rank and affiliation relationships might both influence the SDB rates of female Tibetan macaques significantly, suggesting that SDB is not only an index of anxiety in Tibetan macaques, but also can provide a new insight into evaluation of social relationships between individuals.

  4. Direct NMR Monitoring of Phase Separation Behavior of Highly Supersaturated Nifedipine Solution Stabilized with Hypromellose Derivatives.

    Science.gov (United States)

    Ueda, Keisuke; Higashi, Kenjirou; Moribe, Kunikazu

    2017-07-03

    We investigated the phase separation behavior and maintenance mechanism of the supersaturated state of poorly water-soluble nifedipine (NIF) in hypromellose (HPMC) derivative solutions. Highly supersaturated NIF formed NIF-rich nanodroplets through phase separation from aqueous solution containing HPMC derivative. Dissolvable NIF concentration in the bulk water phase was limited by the phase separation of NIF from the aqueous solution. HPMC derivatives stabilized the NIF-rich nanodroplets and maintained the NIF supersaturation with phase-separated NIF for several hours. The size of the NIF-rich phase was different depending on the HPMC derivatives dissolved in aqueous solution, although the droplet size had no correlation with the time for which NIF supersaturation was maintained without NIF crystallization. HPMC acetate and HPMC acetate succinate (HPMC-AS) effectively maintained the NIF supersaturation containing phase-separated NIF compared with HPMC. Furthermore, HPMC-AS stabilized NIF supersaturation more effectively in acidic conditions. Solution (1)H NMR measurements of NIF-supersaturated solution revealed that HPMC derivatives distributed into the NIF-rich phase during the phase separation of NIF from the aqueous solution. The hydrophobicity of HPMC derivative strongly affected its distribution into the NIF-rich phase. Moreover, the distribution of HPMC-AS into the NIF-rich phase was promoted at lower pH due to the lower aqueous solubility of HPMC-AS. The distribution of a large amount of HPMC derivatives into NIF-rich phase induced the strong inhibition of NIF crystallization from the NIF-rich phase. Polymer distribution into the drug-rich phase directly monitored by solution NMR technique can be a useful index for the stabilization efficiency of drug-supersaturated solution containing a drug-rich phase.

  5. From manager's emotional intelligence to objective store performance: Through store cohesiveness and sales-directed employee behavior

    NARCIS (Netherlands)

    Wilderom, C.P.M.; Hur, YounHee; Wiersma, Uco J.; Berg, van den Peter T.; Lee, Jaehoon

    2015-01-01

    The relationships among manager's emotional intelligence, store cohesiveness, sales-directed employee behavior, and objective store performance were investigated. Non-managerial sales employees of a large retail electronics chain in South Korea (N = 1611) rated the emotional intelligence of their ow

  6. Experimental determination and modeling of the phase behavior for the direct synthesis of dimethyl carbonate from methanol and carbon dioxide

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Musko, Nikolai E.; Baiker, Alfons

    2013-01-01

    This study focuses on the investigation of the phase behavior of mixtures relevant to the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. The bubble points of corresponding quaternary mixtures of varying composition were experimentally determined. The Cubic-Plus-Associati...

  7. The relationship between parent report of adaptive behavior and direct assessment of reading ability in children with autism spectrum disorder.

    Science.gov (United States)

    Arciuli, Joanne; Stevens, Kirsten; Trembath, David; Simpson, Ian Craig

    2013-12-01

    This study was designed to shed light on the profile of reading ability in children with autism spectrum disorder (ASD). A key aim was to examine the relationship between parent report of adaptive behavior and direct assessment of reading ability in these children. The authors investigated children's reading ability using the Wide Range Achievement Test—Fourth Edition (Wilkinson & Robertson, 2006) and the Neale Analysis of Reading Ability—Third Edition (Neale, 2007). Parent report data was collected using the Vineland Adaptive Behavior Scales—Second Edition (Sparrow, Cicchetti, & Balla, 2005). Participants were 21 children with ASD (6-11 years) and their primary caregivers. Direct assessment of children's reading ability showed that some children with ASD have difficulty learning to read and exhibit particular weaknesses in comprehension. The results revealed positive relationships between Vineland Adaptive Behavior Scales scores in the Adaptive Communication domain and direct assessment of children's reading ability across 3 measures of reading (word-level accuracy, passage-level accuracy, and passage-level comprehension). Although literacy levels vary among children with ASD, some clearly struggle with reading. There is a significant relationship between parent self-report of adaptive behavior and direct assessment of children's reading ability.

  8. From manager's emotional intelligence to objective store performance: Through store cohesiveness and sales-directed employee behavior

    NARCIS (Netherlands)

    Wilderom, Celeste P.M.; Hur, YounHee; Wiersma, Uco J.; van den Berg, Peter T.; Lee, Jaehoon

    2015-01-01

    The relationships among manager's emotional intelligence, store cohesiveness, sales-directed employee behavior, and objective store performance were investigated. Non-managerial sales employees of a large retail electronics chain in South Korea (N = 1611) rated the emotional intelligence of their

  9. From manager’s emotional intelligence to objective store performance : Through store cohesiveness and sales-directed employee behavior

    NARCIS (Netherlands)

    Wilderom, C.P.M.; Hur, Y.; Wiersma, U.J.; van den Berg, Petrus; Lee, J.

    2015-01-01

    The relationships among manager's emotional intelligence, store cohesiveness, sales-directed employee behavior, and objective store performance were investigated. Non-managerial sales employees of a large retail electronics chain in South Korea (N = 1611) rated the emotional intelligence of their

  10. Asymmetric ion transport through ion-channel-mimetic solid-state nanopores.

    Science.gov (United States)

    Guo, Wei; Tian, Ye; Jiang, Lei

    2013-12-17

    Both scientists and engineers are interested in the design and fabrication of synthetic nanofluidic architectures that mimic the gating functions of biological ion channels. The effort to build such structures requires interdisciplinary efforts at the intersection of chemistry, materials science, and nanotechnology. Biological ion channels and synthetic nanofluidic devices have some structural and chemical similarities, and therefore, they share some common features in regulating the traverse ionic flow. In the past decade, researchers have identified two asymmetric ion transport phenomena in synthetic nanofluidic structures, the rectified ionic current and the net diffusion current. The rectified ionic current is a diode-like current-voltage response that occurs when switching the voltage bias. This phenomenon indicates a preferential direction of transport in the nanofluidic system. The net diffusion current occurs as a direct product of charge selectivity and is generated from the asymmetric diffusion through charged nanofluidic channels. These new ion transport phenomena and the elaborate structures that occur in biology have inspired us to build functional nanofluidic devices for both fundamental research and practical applications. In this Account, we review our recent progress in the design and fabrication of biomimetic solid-state nanofluidic devices with asymmetric ion transport behavior. We demonstrate the origin of the rectified ionic current and the net diffusion current. We also identify several influential factors and discuss how to build these asymmetric features into nanofluidic systems by controlling (1) nanopore geometry, (2) surface charge distribution, (3) chemical composition, (4) channel wall wettability, (5) environmental pH, (6) electrolyte concentration gradient, and (7) ion mobility. In the case of the first four features, we build these asymmetric features directly into the nanofluidic structures. With the final three, we construct

  11. Direct observation of mother-child communication in pediatric cancer: assessment of verbal and non-verbal behavior and emotion.

    Science.gov (United States)

    Dunn, Madeleine J; Rodriguez, Erin M; Miller, Kimberly S; Gerhardt, Cynthia A; Vannatta, Kathryn; Saylor, Megan; Scheule, C Melanie; Compas, Bruce E

    2011-06-01

    To examine the acceptability and feasibility of coding observed verbal and nonverbal behavioral and emotional components of mother-child communication among families of children with cancer. Mother-child dyads (N=33, children ages 5-17 years) were asked to engage in a videotaped 15-min conversation about the child's cancer. Coding was done using the Iowa Family Interaction Rating Scale (IFIRS). Acceptability and feasibility of direct observation in this population were partially supported: 58% consented and 81% of those (47% of all eligible dyads) completed the task; trained raters achieved 78% agreement in ratings across codes. The construct validity of the IFIRS was demonstrated by expected associations within and between positive and negative behavioral/emotional code ratings and between mothers' and children's corresponding code ratings. Direct observation of mother-child communication about childhood cancer has the potential to be an acceptable and feasible method of assessing verbal and nonverbal behavior and emotion in this population.

  12. Research on the Design and Modification of Asymmetric Spur Gear

    OpenAIRE

    Xiaohe Deng; Lin Hua; Xinghui Han

    2015-01-01

    A design method for the geometric shape and modification of asymmetric spur gear was proposed, in which the geometric shape and modification of the gear can be obtained directly according to the rack-cutter profile. In the geometric design process of the gear, a rack-cutter with different pressure angles and fillet radius in the driving side and coast side was selected, and the generated asymmetric spur gear profiles also had different pressure angles and fillets accordingly. In the modificat...

  13. The development of behavioral and endocrine abnormalities in rats after repeated exposure to direct and indirect stress.

    Science.gov (United States)

    Daniels, Willie Mark Uren; de Klerk Uys, Joachim; van Vuuren, Petra; Stein, Daniel Joseph

    2008-04-01

    The present study compared the effects of direct and indirect stress on the behavior and hypothalamic-pituitary-adrenal axis of rats. Animals were placed in a two compartment box. In one compartment the direct stressed rat was subjected to electric foot shocks randomly applied for 10 minutes (0.5 mA of 1 s duration). In the adjacent compartment, the indirect stressed rats witnessed the application of these electric foot shocks. Our data showed substantial behavioral changes in the open field test, but limited effects in the elevated plus maze. The findings suggested that single and repeated stress exposure may have different consequences, that the effects of stress exposure may develop over time and persist for an extended period, and that both direct and indirect stressed rats displayed a hyposensitive HPA axis following acute restraint stress. Overall our observations moderately indicate direct exposure to elicit behavioral changes, and both direct and indirect exposure to stress to result in aberrations within the neuroendocrine system. With additional development our stress models may be considered for studying the complex interrelationship between an external stressor, and the experience of the organism.

  14. Thermally Induced Asymmetric Buckling of Circular Monolayer Graphene

    Directory of Open Access Journals (Sweden)

    Haw-Long Lee

    2013-01-01

    Full Text Available The asymmetric buckling behaviors of circular monolayer graphene with clamped boundary condition subjected to temperature change are analytically studied based on the nonlocal elasticity theory, including the small length effect. The axisymmetrical and asymmetric critical buckling temperatures and mode shape of different order modes are obtained. According to the analysis, the asymmetric critical buckling temperature of monolayer graphene is larger than the axisymmetric one. The axisymmetrical and asymmetric critical buckling temperatures decrease with increasing nonlocal parameter. In addition, nodal diametrical lines and nodal circles can be found from the modal shapes. In order to avoid destruction of the sensors due to buckling of the structure, they can be placed at the nodal diametrical lines or nodal circles.

  15. ASYMMETRIC VORTICES FLOW OVER SLENDER BODY AND ITS ACTIVE CONTROL AT HIGH ANGLE OF ATTACK

    Institute of Scientific and Technical Information of China (English)

    DENG Xueying; WANG Yankui

    2004-01-01

    The studies of asymmetric vortices flow over slender body and its active control at high angles of attack have significant importance for both academic field and engineering area. This paper attempts to provide an update state of art to the investigations on the fields of forebody asymmetric vortices. This review emphasizes the correlation between micro-perturbation on the model nose and its response and evolution behaviors of the asymmetric vortices. The critical issues are discussed,which include the formation and evolution mechanism of asymmetric multi-vortices; main behaviors of asymmetric vortices flow including its deterministic feature and vortices flow structure; the evolution and development of asymmetric vortices under the perturbation on the model nose; forebody vortex active control especially discussed micro-perturbation active control concept and technique in more detail. However present understanding in this area is still very limited and this paper tries to identify the key unknown problems in the concluding remarks.

  16. an asymmetrically heated rectangular minichannel

    Directory of Open Access Journals (Sweden)

    Strąk Kinga

    2017-01-01

    Full Text Available This paper discusses test results concerning flow boiling heat transfer in a minichannel 1.7 mm in depth, 16 mm in width and 180 mm in length. The essential part of the experimental stand was a vertically oriented rectangular minichannel, which was heated asymmetrically with a plate made of Haynes-230 alloy. Distilled water was used as the cooling fluid. Changes in the temperature on the outer side of the heated plate in the central, axially symmetric part of the channel were measured using infrared thermography. Simultaneously, the other side of the heated plate in contact with the fluid was observed through a glass pane to identify the two-phase flow patterns. The one-dimensional model used for the heat transfer analysis took into account the heat flow direction, which was perpendicular to the direction of the fluid flow in the minichannel. The study involved determining local values of the heat transfer coefficient and generating boiling curves. The data for water were compared with the findings reported for the FC-72 fluid.

  17. Development of snake-directed antipredator behavior by wild white-faced capuchin monkeys: I. Snake-species discrimination.

    Science.gov (United States)

    Meno, Whitney; Coss, Richard G; Perry, Susan

    2013-03-01

    Young animals are known to direct alarm calls at a wider range of species than adults. Our field study examined age-related differences in the snake-directed antipredator behavior of infant, juvenile, and adult white-faced capuchin monkeys (Cebus capucinus) in terms of alarm calling, looking behavior, and aggressive behavior. In the first experiment, we exposed infant and juvenile white-faced capuchins to realistic-looking inflatable models of their two snake predators, the boa constrictior (Boa constrictor) and neotropical rattlesnake (Crotalus durissus) and a white airplane as a novel control. In the second experiment, infants, juveniles, and adults were presented photographic models of a coiled boa constrictor, rattlesnake, indigo snake (Drymarchon corais), a noncapuchin predator, and a white snake-like model. We found that antipredator behavior changed during the immature stage. Infants as young as 4 months old were able to recognize snakes and display antipredator behavior, but engaged in less snake-model discrimination than juveniles. All age classes exhibited a lower response to the white snake-like model, indicating that the absence of color and snake-scale patterns affected snake recognition. Infants also showed a higher level of vigilance after snake-model detection as exhibited by a higher proportion of time spent looking and head cocking at the models. Aggressive antipredator behavior was found in all age classes, but was more prevalent in juveniles and adults than infants. This study adds to the knowledge of development of antipredator behavior in primates by showing that, although alarm calling behavior and predator recognition appear at a very young age in capuchins, snake-species discrimination does not become apparent until the juvenile stage.

  18. Functional Analysis and Treatment of Human-Directed Undesirable Behavior Exhibited by a Captive Chimpanzee

    Science.gov (United States)

    Martin, Allison L.; Bloomsmith, Mollie A.; Kelley, Michael E.; Marr, M. Jackson; Maple, Terry L.

    2011-01-01

    A functional analysis identified the reinforcer maintaining feces throwing and spitting exhibited by a captive adult chimpanzee ("Pan troglodytes"). The implementation of a function-based treatment combining extinction with differential reinforcement of an alternate behavior decreased levels of inappropriate behavior. These findings further…

  19. Direct Measures in Environmental Education Evaluation: Behavioral Intentions versus Observable Actions

    Science.gov (United States)

    Camargo, Camilo; Shavelson, Richard

    2009-01-01

    The objective of many environmental education programs is to promote pro-environmental attitudes and behaviors in students. However, evaluation of these programs has focused on asking participants what they think (attitudes) and what they do (behaviors) regarding the environment problems through self-report questionnaires and interviews. These…

  20. The Effects of Safety Behavior Directed Towards a Safety Cue on Perceptions of Threat

    NARCIS (Netherlands)

    Engelhard, Iris M.; van Uijen, Sophie L.; van Seters, Niels; Velu, Nicolette

    2015-01-01

    Safety behavior involves precautions to prevent or minimize a feared outcome, and is involved in the maintenance of anxiety disorders. Earlier research has shown that safety behavior prevents the extinction of conditioned fear and maintains threat expectations. This study tested whether safety

  1. Direct Behavioral Consultation in Head Start to Increase Teacher Use of Praise and Effective Instruction Delivery

    Science.gov (United States)

    Dufrene, Brad A.; Parker, Kizzy; Menousek, Kathryn; Zhou, Qi; Harpole, Lauren Lestremau; Olmi, D. Joe

    2012-01-01

    Chronic disruptive behaviors during early childhood are associated with many poor developmental outcomes including, but not limited to, school dropout and conduct disorder during adolescence. Much is known regarding effective intervention procedures for disruptive classroom behaviors by preschool children. Unfortunately, evidence-based…

  2. Recent Research on Emergent Verbal Behavior: Clinical Applications and Future Directions

    Science.gov (United States)

    Grow, Laura L.; Kodak, Tiffany

    2010-01-01

    Previous research on the acquisition of verbal behavior in children with developmental disabilities has focused on teaching four primary verbal operants: (1) "mand"; (2) "tact"; (3) "echoic"; and (4) "intraverbal". In Skinner's (1957) analysis of verbal behavior, he stated that each verbal operant is maintained by unique antecedent and consequence…

  3. Direct assessment of tensile stress-crack opening behavior of Strain Hardening Cementitious Composites (SHCC)

    DEFF Research Database (Denmark)

    Pereira, Eduardo B.; Fischer, Gregor; Barros, Joaquim A.O.

    2012-01-01

    at the level of a single crack. The derived tensile stress-crack opening behavior is utilized to analyze and compare the influence of various composite parameters on the resulting tensile behavior. The deformations occurring during tensile loading are furthermore examined using a digital image...

  4. Additive Effects on Asymmetric Catalysis.

    Science.gov (United States)

    Hong, Liang; Sun, Wangsheng; Yang, Dongxu; Li, Guofeng; Wang, Rui

    2016-03-23

    This review highlights a number of additives that can be used to make asymmetric reactions perfect. Without changing other reaction conditions, simply adding additives can lead to improved asymmetric catalysis, such as reduced reaction time, improved yield, or/and increased selectivity.

  5. Effects of a psycho-educational intervention on direct care workers' communicative behaviors with residents with dementia.

    Science.gov (United States)

    Barbosa, Ana; Marques, Alda; Sousa, Liliana; Nolan, Mike; Figueiredo, Daniela

    2016-01-01

    This study assessed the effects of a person-centered care-based psycho-educational intervention on direct care workers' communicative behaviors with people with dementia living in aged-care facilities. An experimental study with a pretest-posttest control-group design was conducted in four aged-care facilities. Two experimental facilities received an 8-week psycho-educational intervention aiming to develop workers' knowledge about dementia, person-centered care competences, and tools for stress management. Control facilities received education only, with no support to deal with stress. In total, 332 morning care sessions, involving 56 direct care workers (female, mean age 44.72 ± 9.02 years), were video-recorded before and 2 weeks after the intervention. The frequency and duration of a list of verbal and nonverbal communicative behaviors were analyzed. Within the experimental group there was a positive change from pre- to posttest on the frequency of all workers' communicative behaviors. Significant treatment effects in favor of the experimental group were obtained for the frequency of inform (p educational intervention can positively affect direct care workers' communicative behaviors with residents with dementia. Further research is required to determine the extent of the benefits of this approach.

  6. Microstructural evolution and corrosion behavior of directionally solidified FeCoNiCrAl high entropy alloy

    Directory of Open Access Journals (Sweden)

    Cui Hongbao

    2011-08-01

    Full Text Available The FeCoNiCrAl alloys have many potential applications in the fields of structural materials, but few attempts were made to characterize the directional solidification of high entropy alloys. In the present research, the microstructure and corrosion behavior of FeCoNiCrAl high entropy alloy have been investigated under directional solidification. The results show that with increasing solidification rate, the interface morphology of the alloy evolves from planar to cellular and dendritic. The electrochemical experiment results demonstrate that the corrosion products of both non-directionally and directionally solidified FeCoNiCrAl alloys appear as rectangular blocks in phases which Cr and Fe are enriched, while Al and Ni are depleted, suggesting that Al and Ni are dissolved into the NaCl solution. Comparison of the potentiodynamic polarization behaviors between the two differently solidified FeCoNiCrAl high entropy alloys in a 3.5%NaCl solution shows that the corrosion resistance of directionally solidified FeCoNiCrAl alloy is superior to that of the non-directionally solidified FeCoNiCrAl alloy.

  7. Simulation-based Estimation of Thermal Behavior of Direct Feed Drive Mechanism with Updated Finite Element Model

    Institute of Scientific and Technical Information of China (English)

    LIN Xiankun; LI Yanjun; LI Haolin

    2014-01-01

    Linear motors generate high heat and cause significant deformation in high speed direct feed drive mechanisms. It is relevant to estimate their deformation behavior to improve their application in precision machine tools. This paper describes a method to estimate its thermal deformation based on updated finite element(FE) model methods. Firstly, a FE model is established for a linear motor drive test rig that includes the correlation between temperature rise and its resulting deformation. The relationship between the input and output variables of the FE model is identified with a modified multivariate input/output least square support vector regression machine. Additionally, the temperature rise and displacements at some critical points on the mechanism are obtained experimentally by a system of thermocouples and an interferometer. The FE model is updated through intelligent comparison between the experimentally measured values and the results from the regression machine. The experiments for testing thermal behavior along with the updated FE model simulations is conducted on the test rig in reciprocating cycle drive conditions. The results show that the intelligently updated FE model can be implemented to analyze the temperature variation distribution of the mechanism and to estimate its thermal behavior. The accuracy of the thermal behavior estimation with the optimally updated method can be more than double that of the initial theoretical FE model. This paper provides a simulation method that is effective to estimate the thermal behavior of the direct feed drive mechanism with high accuracy.

  8. Asymmetric black dyonic holes

    Directory of Open Access Journals (Sweden)

    I. Cabrera-Munguia

    2015-04-01

    Full Text Available A 6-parametric asymptotically flat exact solution, describing a two-body system of asymmetric black dyons, is studied. The system consists of two unequal counterrotating Kerr–Newman black holes, endowed with electric and magnetic charges which are equal but opposite in sign, separated by a massless strut. The Smarr formula is generalized in order to take into account their contribution to the mass. The expressions for the horizon half-length parameters σ1 and σ2, as functions of the Komar parameters and of the coordinate distance, are displayed, and the thermodynamic properties of the two-body system are studied. Furthermore, the seven physical parameters satisfy a simple algebraic relation which can be understood as a dynamical scenario, in which the physical properties of one body are affected by the ones of the other body.

  9. The asymmetric sandwich theorem

    CERN Document Server

    Simons, Stephen

    2011-01-01

    We discuss the asymmetric sandwich theorem, a generalization of the Hahn-Banach theorem. As applications, we derive various results on the existence of linear functionals that include bivariate, trivariate and quadrivariate generalizations of the Fenchel duality theorem. Most of the results are about affine functions defined on convex subsets of vector spaces, rather than linear functions defined on vector spaces. We consider both results that use a simple boundedness hypothesis (as in Rockafellar's version of the Fenchel duality theorem) and also results that use Baire's theorem (as in the Robinson-Attouch-Brezis version of the Fenchel duality theorem). This paper also contains some new results about metrizable topological vector spaces that are not necessarily locally convex.

  10. Asymmetric Dark Matter Models in SO(10)

    CERN Document Server

    Nagata, Natsumi; Zheng, Jiaming

    2016-01-01

    We systematically study the possibilities for asymmetric dark matter in the context of non-supersymmetric SO(10) models of grand unification. Dark matter stability in SO(10) is guaranteed by a remnant $\\mathbb{Z}_2$ symmetry which is preserved when the intermediate scale gauge subgroup of SO(10) is broken by a ${\\bf 126}$ dimensional representation. The asymmetry in the dark matter states is directly generated through the out-of-equilibrium decay of particles around the intermediate scale, or transferred from the baryon/lepton asymmetry generated in the Standard Model sector by leptogenesis. We systematically classify possible asymmetric dark matter candidates in terms of their quantum numbers, and derive the conditions for each case that the observed dark matter density is (mostly) explained by the asymmetry of dark matter particles.

  11. Asymmetric dark matter models in SO(10)

    Science.gov (United States)

    Nagata, Natsumi; Olive, Keith A.; Zheng, Jiaming

    2017-02-01

    We systematically study the possibilities for asymmetric dark matter in the context of non-supersymmetric SO(10) models of grand unification. Dark matter stability in SO(10) is guaranteed by a remnant Z2 symmetry which is preserved when the intermediate scale gauge subgroup of SO(10) is broken by a {126} dimensional representation. The asymmetry in the dark matter states is directly generated through the out-of-equilibrium decay of particles around the intermediate scale, or transferred from the baryon/lepton asymmetry generated in the Standard Model sector by leptogenesis. We systematically classify possible asymmetric dark matter candidates in terms of their quantum numbers, and derive the conditions for each case that the observed dark matter density is (mostly) explained by the asymmetry of dark matter particles.

  12. Direct Electrochemical Evidence of the Dissociation and Adsorption Behavior of Acetonitrile at Gold Electrodes by Ultrafast Voltammetry

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Ultrafast cyclic voltammetry was used to study the redox behavior of a gold electrode in acetonitrile. The direct electrochemical evidence of the dissociation and adsorption behavior of acetonitrile at gold electrodes was found. It could be stated that two consecutive redox paths are involved, each with a special adsorption state acting as the reaction intermediate. The mean value,obtained of the electron-transfer rate constant of the second path, was 1.3 × 105 s-1 with a standard deviation of 0.24 × 105 s-1.

  13. Designing serious video games for health behavior change: current status and future directions.

    Science.gov (United States)

    Thompson, Debbe

    2012-07-01

    Serious video games for health are designed to entertain while changing a specific health behavior. This article identifies behavioral principles that can guide the development of serious video games focused on changing a variety of health behaviors, including those attempting to decrease risk of obesity and type 2 diabetes. Guidelines discussed include how to develop video games that provide a solid foundation for behavior change by enhancing a player's knowledge and skill, ways in which personal mastery experiences can be incorporated into a video game environment, using game characters and avatars to promote observational learning, creating personalized experiences through tailoring, and the importance of achieving a balance between "fun-ness" and "seriousness." The article concludes with suggestions for future research needed to inform this rapidly growing field. © 2012 Diabetes Technology Society.

  14. Value-directed human behavior analysis from video using partially observable Markov decision processes.

    Science.gov (United States)

    Hoey, Jesse; Little, James J

    2007-07-01

    This paper presents a method for learning decision theoretic models of human behaviors from video data. Our system learns relationships between the movements of a person, the context in which they are acting, and a utility function. This learning makes explicit that the meaning of a behavior to an observer is contained in its relationship to actions and outcomes. An agent wishing to capitalize on these relationships must learn to distinguish the behaviors according to how they help the agent to maximize utility. The model we use is a partially observable Markov decision process, or POMDP. The video observations are integrated into the POMDP using a dynamic Bayesian network that creates spatial and temporal abstractions amenable to decision making at the high level. The parameters of the model are learned from training data using an a posteriori constrained optimization technique based on the expectation-maximization algorithm. The system automatically discovers classes of behaviors and determines which are important for choosing actions that optimize over the utility of possible outcomes. This type of learning obviates the need for labeled data from expert knowledge about which behaviors are significant and removes bias about what behaviors may be useful to recognize in a particular situation. We show results in three interactions: a single player imitation game, a gestural robotic control problem, and a card game played by two people.

  15. Dynamic behavior and sound transmission analysis of a fluid structure coupled system using the direct-BEM/FEM

    Science.gov (United States)

    Tong, Z.; Zhang, Y.; Zhang, Z.; Hua, H.

    2007-01-01

    A direct-BEM/Fem method was proposed to analyze the vibration and acoustic radiation characteristics of a submerged structure. Model parameters of the structure and the fluid-structure interaction due to surrounding water were analyzed by using FEM and direct BEM. Vibration velocity of the outer hull surface and underwater sound pressure were computed through modal superposition technique. The direct-BEM/FEM method was first validated by analyzing a submerged cylindrical shell, then was used to analyze the vibro-acoustic behavior of a submarine stern structure. The results have demonstrated the direct-BEM/FEM method is more effective than FEM in computing the underwater sound radiation of the stern structure.

  16. Polarization dependent switching of asymmetric nanorings with a circular field

    Directory of Open Access Journals (Sweden)

    Nihar R. Pradhan

    2016-01-01

    Full Text Available We experimentally investigated the switching from onion to vortex states in asymmetric cobalt nanorings by an applied circular field. An in-plane field is applied along the symmetric or asymmetric axis of the ring to establish domain walls (DWs with symmetric or asymmetric polarization. A circular field is then applied to switch from the onion state to the vortex state, moving the DWs in the process. The asymmetry of the ring leads to different switching fields depending on the location of the DWs and direction of applied field. For polarization along the asymmetric axis, the field required to move the DWs to the narrow side of the ring is smaller than the field required to move the DWs to the larger side of the ring. For polarization along the symmetric axis, establishing one DW in the narrow side and one on the wide side, the field required to switch to the vortex state is an intermediate value.

  17. Asymmetric wave transmission in a diatomic acoustic/elastic metamaterial

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bing; Tan, K. T., E-mail: ktan@uakron.edu [Department of Mechanical Engineering, The University of Akron, Akron, Ohio 44325-3903 (United States)

    2016-08-21

    Asymmetric acoustic/elastic wave transmission has recently been realized using nonlinearity, wave diffraction, or bias effects, but always at the cost of frequency distortion, direction shift, large volumes, or external energy. Based on the self-coupling of dual resonators, we propose a linear diatomic metamaterial, consisting of several small-sized unit cells, to realize large asymmetric wave transmission in low frequency domain (below 1 kHz). The asymmetric transmission mechanism is theoretically investigated, and numerically verified by both mass-spring and continuum models. This passive system does not require any frequency conversion or external energy, and the asymmetric transmission band can be theoretically predicted and mathematically controlled, which extends the design concept of unidirectional transmission devices.

  18. Cost Behavior

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    The objective of this dissertation is to investigate determinants and consequences of asymmetric cost behavior. Asymmetric cost behavior arises if the change in costs is different for increases in activity compared to equivalent decreases in activity. In this case, costs are termed “sticky......” if the change is less when activity falls than when activity rises, whereas costs are termed “anti-sticky” if the change is more when activity falls than when activity rises. Understanding such cost behavior is especially relevant for decision-makers and financial analysts that rely on accurate cost information...

  19. Cost Behavior

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    The objective of this dissertation is to investigate determinants and consequences of asymmetric cost behavior. Asymmetric cost behavior arises if the change in costs is different for increases in activity compared to equivalent decreases in activity. In this case, costs are termed “sticky......” if the change is less when activity falls than when activity rises, whereas costs are termed “anti-sticky” if the change is more when activity falls than when activity rises. Understanding such cost behavior is especially relevant for decision-makers and financial analysts that rely on accurate cost information...

  20. Signage as a tool for behavioral change: Direct and indirect routes to understanding the meaning of a sign.

    Science.gov (United States)

    Meis, Julia; Kashima, Yoshihisa

    2017-01-01

    Signs, prompts, and symbols are a common means to change behavior in our society. Understanding the psychological mechanisms by which signage influences behavior is a critical first step to achieve the desired outcome. In the current research, we propose a theoretical model of sign-to-behavior process. The model suggests that when one encounters a sign, it is encoded to construct an action representation (comprehension process), which is then acted on unless its enactment is inhibited (decision process). We test the implications of the model in two studies. In support of our hypothesis, for unfamiliar signs, clarity of purpose predicts perceived effectiveness of a sign; however, for familiar signs, clarity of purpose does not matter. Insights gained from the studies will help to design effective signs. Practical implications of the model are discussed, and future research directions are outlined.

  1. Parenting Styles and Practices in Children's Obesogenic Behaviors: Scientific Gaps and Future Research Directions

    Science.gov (United States)

    Hennessy, Erin; McSpadden, Kate; Oh, April

    2013-01-01

    Abstract Given the emerging global childhood obesity epidemic and the specter of a generation of children who will have a shorter life expectancy than that of their parents, recent research has focused on factors that influence children's weight status and obesogenic behaviors (i.e., eating, physical activity, and screen media use). Parents act as primary socializing agents for children, and thus growing evidence supports the role of parenting styles and practices in children's obesity-related behaviors and weight. Studying these processes in children and adolescents is important for several reasons. First, diet and physical activity behaviors and weight status track from childhood and adolescence into adulthood. Furthermore, diet and physical activity behaviors and weight status confer significant risk for cancer, diabetes, cardiovascular disease, and other chronic diseases. The purpose of this article is to describe the scientific gaps that need to be addressed to develop a more informed literature on parenting styles and practices in the domains of weight status and obesogenic behaviors, as identified by an expert panel assembled by the National Cancer Institute. PMID:23944926

  2. Parenting styles and practices in children's obesogenic behaviors: scientific gaps and future research directions.

    Science.gov (United States)

    Patrick, Heather; Hennessy, Erin; McSpadden, Kate; Oh, April

    2013-08-01

    Given the emerging global childhood obesity epidemic and the specter of a generation of children who will have a shorter life expectancy than that of their parents, recent research has focused on factors that influence children's weight status and obesogenic behaviors (i.e., eating, physical activity, and screen media use). Parents act as primary socializing agents for children, and thus growing evidence supports the role of parenting styles and practices in children's obesity-related behaviors and weight. Studying these processes in children and adolescents is important for several reasons. First, diet and physical activity behaviors and weight status track from childhood and adolescence into adulthood. Furthermore, diet and physical activity behaviors and weight status confer significant risk for cancer, diabetes, cardiovascular disease, and other chronic diseases. The purpose of this article is to describe the scientific gaps that need to be addressed to develop a more informed literature on parenting styles and practices in the domains of weight status and obesogenic behaviors, as identified by an expert panel assembled by the National Cancer Institute.

  3. Photoresponse of silicon with asymmetric area contacts

    Science.gov (United States)

    Rabbani, M. Golam; Sundararajan, Jency P.; Verma, Amit; Nekovei, Reza; Khader, Mahmoud M.; Darling, R. B.; Patil, Sunil R.

    2017-01-01

    We report on high performance metal-semiconductor-metal (MSM) photosensors based on asymmetric metal pad areas. The reported devices require a single-step metal deposition, and exhibit large photo response even under zero-bias. Moreover the devices offer fast and stable light switching behavior. Device fabrication and electrical characterization results are presented that are further analyzed with TCAD modeling and simulation. Device simulations show that contact asymmetry along with surface recombination and barrier lowering plays an important role in the MSM I-V characteristics.

  4. Nanotribology of Symmetric and Asymmetric Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Shinji Yamada

    2010-03-01

    Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.

  5. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  6. Association between victimization by bullying and direct self injurious behavior among adolescence in Europe: a ten-country study.

    Science.gov (United States)

    Brunstein Klomek, Anat; Snir, Avigal; Apter, Alan; Carli, Vladimir; Wasserman, Camilla; Hadlaczky, Gergö; Hoven, Christina W; Sarchiapone, Marco; Balazs, Judit; Bobes, Julio; Brunner, Romuald; Corcoran, Paul; Cosman, Doina; Haring, Christian; Kahn, Jean-Pierre; Kaess, Michael; Postuvan, Vita; Sisask, Merike; Tubiana, Alexandra; Varnik, Airi; Žiberna, Janina; Wasserman, Danuta

    2016-11-01

    Previous studies have examined the association between victimization by bullying and both suicide ideation and suicide attempts. The current study examined the association between victimization by bullying and direct-self-injurious behavior (D-SIB) among a large representative sample of male and female adolescents in Europe. This study is part of the Saving and Empowering Young Lives in Europe (SEYLE) study and includes 168 schools, with 11,110 students (mean age = 14.9, SD = 0.89). Students were administered a self-report survey within the classroom, in which they were asked about three types of victimization by bullying (physical, verbal and relational) as well as direct self-injurious behavior (D-SIB). Additional risk factors (symptoms of depression and anxiety, suicide ideation, suicide attempts, loneliness, alcohol consumption, drug consumption), and protective factors (parent support, peer support, pro-social behavior) were included. The three types of victimization examined were associated with D-SIB. Examination of gender as moderator of the association between victimization (relational, verbal, and physical) and D-SIB yielded no significant results. As for the risk factors, depression, but not anxiety, partially mediated the effect of relational victimization and verbal victimization on D-SIB. As for the protective factors, students with parent and peer support and those with pro-social behaviors were at significantly lower risk of engaging in D-SIB after being victimized compared to students without support/pro-social behaviors. This large-scale study has clearly demonstrated the cross-sectional association between specific types of victimization with self-injurious behavior among adolescents and what may be part of the risk and protective factors in this complex association.

  7. Computational design of microscopic swimmers and capsules: From directed motion to collective behavior

    Energy Technology Data Exchange (ETDEWEB)

    Nikolov, Svetoslav V.; Shum, Henry; Balazs, Anna C.; Alexeev, Alexander

    2016-02-01

    Systems of motile microscopic particles can exhibit behaviors that resemble those of living microorganisms, including cooperative motion, self-organization, and adaptability to changing environments. Using mesoscale computational modeling, we design synthetic microswimmers and microcapsules that undergo controllable, self-propelled motion in solution. Stimuli-responsive hydrogels are used to actuate the microswimmers and to enable their navigation and chemotaxing behavior. The self-propelled motion of microcapsules on solid surfaces is achieved by the release of encapsulated solutes that alter the surface adhesiveness. These signaling solutes also enable interactions among multiple microcapsules that lead to complex, cooperative behavior. Our findings provide guidelines for creating microscopic devices and machines able to autonomously move and mimic the communication and chemotaxis of biological microorganisms.

  8. Automaticity of social behavior: direct effects of trait construct and stereotype-activation on action.

    Science.gov (United States)

    Bargh, J A; Chen, M; Burrows, L

    1996-08-01

    Previous research has shown that trait concepts and stereotype become active automatically in the presence of relevant behavior or stereotyped-group features. Through the use of the same priming procedures as in previous impression formation research, Experiment 1 showed that participants whose concept of rudeness was printed interrupted the experimenter more quickly and frequently than did participants primed with polite-related stimuli. In Experiment 2, participants for whom an elderly stereotype was primed walked more slowly down the hallway when leaving the experiment than did control participants, consistent with the content of that stereotype. In Experiment 3, participants for whom the African American stereotype was primed subliminally reacted with more hostility to a vexatious request of the experimenter. Implications of this automatic behavior priming effect for self-fulfilling prophecies are discussed, as is whether social behavior is necessarily mediated by conscious choice processes.

  9. Impairments in goal-directed actions predict treatment response to cognitive-behavioral therapy in social anxiety disorder.

    Directory of Open Access Journals (Sweden)

    Gail A Alvares

    Full Text Available Social anxiety disorder is characterized by excessive fear and habitual avoidance of social situations. Decision-making models suggest that patients with anxiety disorders may fail to exhibit goal-directed control over actions. We therefore investigated whether such biases may also be associated with social anxiety and to examine the relationship between such behavior with outcomes from cognitive-behavioral therapy. Patients diagnosed with social anxiety and controls completed an instrumental learning task in which two actions were performed to earn food outcomes. After outcome devaluation, where one outcome was consumed to satiety, participants were re-tested in extinction. Results indicated that, as expected, controls were goal-directed, selectively reducing responding on the action that previously delivered the devalued outcome. Patients with social anxiety, however, exhibited no difference in responding on either action. This loss of a devaluation effect was associated with greater symptom severity and poorer response to therapy. These findings indicate that variations in goal-directed control in social anxiety may represent both a behavioral endophenotype and may be used to predict individuals who will respond to learning-based therapies.

  10. Direct and Indirect Effects of Behavioral Parent Training on Infant Language Production.

    Science.gov (United States)

    Bagner, Daniel M; Garcia, Dainelys; Hill, Ryan

    2016-03-01

    Given the strong association between early behavior problems and language impairment, we examined the effect of a brief home-based adaptation of Parent-child Interaction Therapy on infant language production. Sixty infants (55% male; mean age 13.47±1.31 months) were recruited at a large urban primary care clinic and were included if their scores exceeded the 75th percentile on a brief screener of early behavior problems. Families were randomly assigned to receive the home-based parenting intervention or standard pediatric primary care. The observed number of infant total (i.e., token) and different (i.e., type) utterances spoken during an observation of an infant-led play and a parent-report measure of infant externalizing behavior problems were examined at pre- and post-intervention and at 3- and 6-month follow-ups. Infants receiving the intervention demonstrated a significantly higher number of observed different and total utterances at the 6-month follow-up compared to infants in standard care. Furthermore, there was an indirect effect of the intervention on infant language production, such that the intervention led to decreases in infant externalizing behavior problems from pre- to post-intervention, which, in turn, led to increases in infant different utterances at the 3- and 6-month follow-ups and total utterances at the 6-month follow-up. Results provide initial evidence for the effect of this brief and home-based intervention on infant language production, including the indirect effect of the intervention on infant language through improvements in infant behavior, highlighting the importance of targeting behavior problems in early intervention.

  11. Computer-assisted direct observation of behavioral agitation, engagement, and affect in long-term care residents.

    Science.gov (United States)

    Casey, Anne-Nicole; Low, Lee-Fay; Goodenough, Belinda; Fletcher, Jennifer; Brodaty, Henry

    2014-07-01

    The objectives of the current research were (1) to test and evaluate the investigator-designed Behavior, Engagement, and Affect Measure (BEAM) touchpad direct observational data collection tool, and (2) to implement this tool to investigate residents' patterns of behavioral agitation, engagement, affect, behaviors associated with positive mood, general time-activity use, and social interactions within long-term care. Raters collected cross-sectional observational data and conducted semistructured interviews with participants of the Sydney Multisite Intervention of LaughterBosses and ElderClowns (SMILE) Study. Researchers tested the BEAM's reliability and validity and evaluated the instrument's discriminate validity for sampling resident behaviors. Data were collected in 36 long-term care homes. The sample included low-care hostels, high-care nursing homes, and residential facilities offering aging-in-place. Participants were 406 residents aged 52 to 105 years, with and without dementia. Researchers collected direct observational data using the BEAM and operationalized behavioral domains based largely on concepts from Kitwood's model of person-centered care. Care staff reported on resident behavior using standardized measures of agitation, depression, quality of life, and social engagement. The BEAM showed moderate-to-substantial interrater reliability and slight-to-moderate correlations with staff-report data gathered through standardized questionnaire measures. Observations showed that residents spent the greatest amount of time stationary and expressing little emotion, although actively engaged with their environment. Residents were observed to be coping adequately and experiencing a positive social and/or positive care interaction in approximately half of observations; however, close to a third of ratings identified "ill-being." Residents showed more positive behavior, appeared happier and less anxious, and exhibited higher "well-being" during structured

  12. Effect of asymmetric gravity jitter excited slosh waves at liquid-vapor interface under microgravity

    Science.gov (United States)

    Hung, R. J.; Pan, H. L.; Lee, C. C.; Leslie, F. W.

    1992-01-01

    The dynamical behavior of fluids affected by the asymmetric gravity jitter oscillations, in particular the effect of surface tension on partially-filled rotating fluids (cryogenic liquid helium and helium vapor) in a sub-scale Gravity Probe-B Spacecraft propellant dewar tank imposed by time-dependent various directions of background gravity environment have been investigated. Results show that lower frequency gravity jitter imposed on the time-dependent variations of the direction of background gravity induced a greater amplitude of oscillations and a stronger degree of asymmetry in liquid-vapor interface geometry than that made by the higher frequency gravity jitter. Furthermore, the greater the components of background gravity in radial and circumferential directions will provide a greater contribution in driving more to the increasing amplitude and degrees of symmetry of liquid-vapor interface profiles which, in turn, modify the disturbance of moment of inertia and angular momentum of spacecraft.

  13. Experimental Study on Leakage Flow in Labyrinth Seals with Asymmetric Geometries

    Science.gov (United States)

    Nishii, Kazufumi; Furukawa, Akinori; Watanabe, Satoshi; Miyake, Kunihiro

    2010-06-01

    The labyrinth seal is one of non-contact seals, which is used as a seal device of rotary machines from reasons of the lubrication free and small losses. So far, many researchers have investigated the characteristics and suitable geometries of labyrinth seals, though only one directional flow of the seal has been focused up to now. As flow direction in the seal becomes changeable depending on the gas-purge system and the inner pressure variation of machines for recent applications, a guideline of designing labyrinth seal with changeable flow directions is required. In the present report, effects of seal characteristics and internal flow behaviors on various shapes of asymmetric convexity in labyrinth seals are experimentally investigated and relations between pressure loss and convexity geometries are discussed for designing a suitable seal.

  14. The opening and reading behavior of business-to-business direct mail

    NARCIS (Netherlands)

    De Wulf, K; Hoekstra, JC; Commandeur, HR

    2000-01-01

    Companies who are able to optimize their target audience's opening and reading behavior of commercial business-to-business mailings realize two objectives at the same time: increase response rates of these mailings and lift the level of exposure of their company, its products, and/or services. Howev

  15. Proactive Motivation and Engagement in Career Behaviors: Investigating Direct, Mediated, and Moderated Effects

    Science.gov (United States)

    Hirschi, Andreas; Lee, Bora; Porfeli, Erik J.; Vondracek, Fred W.

    2013-01-01

    Proactive career behaviors become increasingly important in today's career environment, but little is known about how and when motivational patterns affect individual differences. In a six-month longitudinal study among German university students (Study 1; N = 289) it was demonstrated that motivation in terms of "can do" (self-efficacy…

  16. Goal Statements and Goal-Directed Behavior: A Relational Frame Account of Goal Setting in Organizations

    Science.gov (United States)

    O'Hora, Denis; Maglieri, Kristen A.

    2006-01-01

    Goal setting has consistently been shown to increase performance under specific conditions. These goal setting effects have previously been explored from both a cognitive perspective and in terms of traditional behavioral concepts. We highlight limitations of these approaches and propose a novel account based on Relational Frame Theory. This…

  17. Parent-directed cognitive behavioral therapy for young anxious children: a pilot study

    NARCIS (Netherlands)

    van der Sluis, C.M.; van der Bruggen, C.O.; Brechman-Toussaint, M.L.; Thissen, M.A.P.; Bögels, S.M.

    2012-01-01

    Anxiety in children age 8 years and above has been successfully treated with cognitive behavioral therapy (CBT). However, the efficacy of CBT for anxious children ages 4-7 years has not, to date, been fully investigated. This paper piloted a CBT intervention targeting child anxiety that was delivere

  18. Family Communication Patterns and Relational Maintenance Behavior: Direct and Mediated Associations with Friendship Closeness

    Science.gov (United States)

    Ledbetter, Andrew M.

    2009-01-01

    In this study, both face-to-face and online relational maintenance behaviors were tested as mediators of family communication patterns and closeness with a same-sex friend. Participants included 417 young adults recruited from communication courses at a large university in the Midwestern United States. The obtained structural model demonstrated…

  19. Pattern Separation and Goal-Directed Behavior in the Aged Canine

    Science.gov (United States)

    Snigdha, Shikha; Yassa, Michael A.; deRivera, Christina; Milgram, Norton W.; Cotman, Carl W.

    2017-01-01

    The pattern separation task has recently emerged as a behavioral model of hippocampus function and has been used in several pharmaceutical trials. The canine is a useful model to evaluate a multitude of hippocampal-dependent cognitive tasks that parallel those in humans. Thus, this study was designed to evaluate the suitability of pattern…

  20. Asymmetric Bessel modes.

    Science.gov (United States)

    Kotlyar, V V; Kovalev, A A; Soifer, V A

    2014-04-15

    We propose a new, three-parameter family of diffraction-free asymmetric elegant Bessel modes (aB-modes) with an integer and fractional orbital angular momentum (OAM). The aB-modes are described by the nth-order Bessel function of the first kind with complex argument. The asymmetry degree of the nonparaxial aB-mode is shown to depend on a real parameter c≥0: when c=0, the aB-mode is identical to a conventional radially symmetric Bessel mode; with increasing c, the aB-mode starts to acquire a crescent form, getting stretched along the vertical axis and shifted along the horizontal axis for c≫1. On the horizontal axis, the aB-modes have a denumerable number of isolated intensity zeros that generate optical vortices with a unit topological charge of opposite sign on opposite sides of 0. At different values of the parameter c, the intensity zeros change their location on the horizontal axis, thus changing the beam's OAM. An isolated intensity zero on the optical axis generates an optical vortex with topological charge n. The OAM per photon of an aB-mode depends near-linearly on c, being equal to ℏ(n+cI1(2c)/I0(2c)), where ℏ is the Planck constant and In(x) is a modified Bessel function.

  1. Asymmetric Gepner Models (Revisited)

    CERN Document Server

    Gato-Rivera, B

    2010-01-01

    We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as th...

  2. Differences in directional sound source behavior and perception between assorted computer room models

    DEFF Research Database (Denmark)

    Vigeant, M. C.; Wang, L. M.; Rindel, Jens Holger

    2004-01-01

    Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels....... The effect of changing the room's material properties was studied in relation to turning the source around 180 deg and on the range of acoustic parameters from the four- and 13 beams. As the room becomes increasingly diffuse, the importance of the modeled directivity decreases when considering reverberation...... time. However, for the three other parameters evaluated (sound-pressure level, clarity index, and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity when using computer...

  3. Asymmetric Heat Conduction in One-Dimensional Hard-Point Model with Mass Gradient

    Institute of Scientific and Technical Information of China (English)

    LI Hai-Bin; NIE Qing-Miao; XIN Xiao-Tian

    2009-01-01

    The heat conduction in a one-dimensional (1D) hard-point model with mass gradient is studied. Using numerical simulation, we find an asymmetric heat conduction in this model with greater heat current in the direction of mass increase. The increase of temperature gradient, mass gradient and system size are found to enhance the asymmetric heat conduction. Based on the collision dynamic of a hard-point particle, we give a qualitative explanation for the underlying mechanism of asymmetric effect.

  4. Magnetically Modified Asymmetric Supercapacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle life....

  5. Founder effects and the evolution of asymmetrical sexual isolation in a rapidly-speciating clade

    Institute of Scientific and Technical Information of China (English)

    Kevin P.OH; Gina L.CONTE; Kerry L.SHAW

    2013-01-01

    Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages.When present,asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits.In particular,Kaneshiro's hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ‘derived’ founding populations are subject to severe population bottlenecks,accompanied by a relaxation of sexual selection relative to ‘ancestral’ source populations.In the present study,we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets,representing ‘ancestral’ (L.makaio) and ‘derived’ (L.nigra)taxa.While crickets in this genus are notable for rapid divergence of male courtship songs,these species share similar song types,thus suggesting that pattems of sexual isolation are likely due to other mating cues.Analysis of behavioral responses in conspecific and heterospecific ‘no-choice’ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kaneshiro's hypothesis,wherein we observed a significant reduction in mating success for crosses involving ‘derived’ males paired with ‘ancestral’ females,compared to the reciprocal heterospecific and both conspecific pairings.Further dissection of courtship behaviors suggested this difference did not reflect male mate choice,but rather,marked reduced spermatophore acceptance rates by ‘ancestral’ females paired with ‘derived’ males.The results are discussed with respect to founder effect models of speciation and the potential role of chemosensory signals in mate choice in these species.

  6. Effect of Re Addition and Withdrawal Rate on the Solidification Behavior of Directionally Solidified Superalloy AM3

    Institute of Scientific and Technical Information of China (English)

    F.Long; Y.S.Yoo; S.M.Seo; T.Jin; Z.Q.Hu; C.Y.Jo

    2011-01-01

    The influence of Re addition and withdrawal rate on the solidification behavior of the first generation single crystal superalloy AM3 was investigated by directional solidification and quenching experiments. The primary dendrite arm spacing and eutectic volume fraction were measured from directionally solidified superalloy AM3 with different Re contents. It is found that the primary dendrite arm spacing is determined by the withdrawal rate, and Re does not influence on the value. The eutectic fraction increases with increasing Re addition. Partition coefficients of alloying elements were investigated with energy-dispersive X-ray spectrometry (EDS) analysis. The data was submitted to a statistical treatment to establish the solidification path, and the partition coefficients were measured by fitting the curve with a modified Scheil formula. It is shown that the addition of Re results in bigger microsegregation of alloying elements in directionally solidified AM3 superalloy.

  7. Bound states in open coupled asymmetrical waveguides and quantum wires

    CERN Document Server

    Amore, Paolo; Terrero-Escalante, Cesar A

    2011-01-01

    The behavior of bound states in asymmetric cross, T and L shaped configurations is considered. Because of the symmetries of the wavefunctions, the analysis can be reduced to the case of an electron localized at the intersection of two orthogonal crossed wires of different width. Numerical calculations show that the fundamental mode of this system remains bound for the widths that we have been able to study directly; moreover, the extrapolation of the results obtained for finite widths suggests that this state remains bound even when the width of one arm becomes infinitesimal. We provide a qualitative argument which explains this behavior and that can be generalized to the lowest energy states in each symmetry class. In the case of odd-odd states of the cross we find that the lowest mode is bounded when the width of the two arms is the same and stays bound up to a critical value of the ratio between the widths; in the case of the even-odd states we find that the lowest mode is unbound up to a critical value of...

  8. On Asymmetric Quantum MDS Codes

    CERN Document Server

    Ezerman, Martianus Frederic; Ling, San

    2010-01-01

    Assuming the validity of the MDS Conjecture, the weight distribution of all MDS codes is known. Using a recently-established characterization of asymmetric quantum error-correcting codes, linear MDS codes can be used to construct asymmetric quantum MDS codes with $d_{z} \\geq d_{x}\\geq 2$ for all possible values of length $n$ for which linear MDS codes over $\\F_{q}$ are known to exist.

  9. Multicatalyst system in asymmetric catalysis

    CERN Document Server

    Zhou, Jian

    2014-01-01

    This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis.  Helps organic chemists perform more efficient catalysis with step-by-step methods  Overviews new concepts and progress for greener and economic catalytic reactions  Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions   Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance

  10. Asymmetric cation-binding catalysis

    DEFF Research Database (Denmark)

    Oliveira, Maria Teresa; Lee, Jiwoong

    2017-01-01

    and KCN, are selectively bound to the catalyst, providing exceptionally high enantioselectivities for kinetic resolutions, elimination reactions (fluoride base), and Strecker synthesis (cyanide nucleophile). Asymmetric cation-binding catalysis was recently expanded to silicon-based reagents, enabling...... solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...

  11. Phase diagram of highly asymmetric binary hardsphere mixtures

    NARCIS (Netherlands)

    Dijkstra, M.|info:eu-repo/dai/nl/123538807; van Roij, R.H.H.G.|info:eu-repo/dai/nl/152978984; Evans, R.

    We study the phase behavior and structure of highly asymmetric binary hard-sphere mixtures. By first integrating out the degrees of freedom of the small spheres in the partition function we derive a formal expression for the effective Hamiltonian of the large spheres. Then using an explicit pairwise

  12. Future directions in communication research: individual health behaviors and the influence of family communication.

    Science.gov (United States)

    Baiocchi-Wagner, Elizabeth A

    2015-01-01

    Although numerous fields continue to advance research toward various areas of health prevention, communication researchers have yet to examine fully the link between communication and health improvement. This is particularly true of those studying the intersections of family and health communication--unfortunate, given that family members serve as primary socialization agents in health attitudes and behaviors. Using the example of obesity-related health behaviors, the following essay advances the argument that continued research aimed at understanding the intersection of health and families' communicative influence may help to illuminate the nature, causes, and redress to health issues that are correlated with individual health practices. This is accomplished by (a) reviewing contributions and limitations of pioneering studies in (family) health literature and (b) offering three key research areas for health communication exploration that will move scholars toward communication-based solutions (e.g., family-level communication health interventions).

  13. Asymmetric Capacitance Behavior Based on the Relationship between Ion Dimension and Pore Size%基于离子尺寸与孔径关系的不对称电容行为

    Institute of Scientific and Technical Information of China (English)

    孙刚伟; 宋文华; 刘小军; 乔文明; 凌立成

    2011-01-01

    采用具有不同孔径分布的活性炭作为电极材料,研究了离子尺寸与孔结构对电容性能的影响.结果表明,正负极表现出不对称的电容行为,正负极的质量比电容分别为113和7 F·g-1.在负极电位区间,循环伏安曲线的响应电流明显减小.材料表面最大电荷存储量的理论计算与实验结果有着很好的一致性,这些结果表明用于阳离子电荷存储的电极孔隙空间不够发达,导致电容器在充电过程中负极材料表面达到电荷饱和状态,进而表现出较差的电容行为,然而,四氟硼酸根阴离子可以进入到正极电极材料大多数孔道中,电极未发生电荷饱和效应,表现出优异的电容行为,负极较低的比电容将会影响电容器的整体性能,因此,正负极应当根据离子尺寸与电极材料孔结构的构效关系进行匹配,以使电容器的比电容最大化.%We reported on the capacitive behaviors regarding to the relationship between ion size and pore architecture,using activated carbons with an adjusted pore structure as electrode materials.The results revealed that an asymmetric capacitance response occurred in both electrodes.The gravimetric capacitances for the positive and negative electrodes were 113 and 7 F.g-1,respectively.A significant current decay was presented in the negative region of cyclic voltammetry curve.Experimental and calculated maximum storage charges had a good agreement.This results suggested that the insufficiently developed pore architecture for cation accommodation led to a saturation effect on the active surface,consequently,a deteriorated capacitive performance in the negative electrode.Contrarily,when pore size was larger than tetrafluoroborate dimension,the saturation effect was not found.However,this was at the expense of the lower specific area capacitance in the positive electrode.The poor capacitive behavior of the negative electrode would limit the usable voltage of the cell system and

  14. Seasonality directs contrasting food collection behavior and nutrient regulation strategies in ants.

    Directory of Open Access Journals (Sweden)

    Steven C Cook

    Full Text Available Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p to carbohydrate (c ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer, and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant.

  15. The Role of Pheromonal Responses in Rodent Behavior: Future Directions for the Development of Laboratory Protocols

    Science.gov (United States)

    Bind, Rebecca H; Minney, Sarah M; Rosenfeld, SaraJane; Hallock, Robert M

    2013-01-01

    Pheromones—chemical signals that can elicit responses in a conspecific—are important in intraspecies communication. Information conveyed by pheromones includes the location of an animal, the presence of food or a threat, sexual attraction, courtship, and dam–pup interactions. These chemical messages remain intact and volatile even when animals, such as rodents, are housed in laboratories rather than their natural environment. Laboratory protocols, such as the cage cleaning and sanitation processes, as well as general housing conditions can alter a rodent's normal production of pheromones in both amount and type and thus may affect behavior. In addition, some procedures induce the release of alarm pheromones that subsequently alter the behavior of other rodents. To prevent pheromonal interference and stress-induced pheromonal release in their research subjects, experimenters should assess current laboratory protocols regarding cage cleaning processes, housing designs, and behavioral assays. Here we discuss how the most commonly used laboratory procedures can alter pheromonal signaling and cause confounding effects. PMID:23562094

  16. Differences in directional sound source behavior and perception between assorted computer room models

    DEFF Research Database (Denmark)

    Vigeant, Michelle C.; Wang, Lily M.; Rindel, Jens Holger

    2004-01-01

    Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels...... pursued. The effect of changing the room’s material properties was studied in relation to turning the source around 180 degrees and on the range of acoustic parameters from the four and thirteen beams. As the room becomes increasingly diffuse, the importance of the modeled directivity decreases when...... when using computer modeling. [Work supported by the National Science Foundation.]...

  17. A role of phase-resetting in coordinating large scale neural oscillations during attention and goal-directed behavior

    Directory of Open Access Journals (Sweden)

    Benjamin eVoloh

    2016-03-01

    Full Text Available Short periods of oscillatory activation are ubiquitous signatures of neural circuits. A broad range of studies documents not only their circuit origins, but also a fundamental role for oscillatory activity in coordinating information transfer during goal directed behavior. Recent studies suggest that resetting the phase of ongoing oscillatory activity to endogenous or exogenous cues facilitates coordinated information transfer within circuits and between distributed brain areas. Here, we review evidence that pinpoints phase resetting as a critical marker of dynamic state changes of functional networks. Phase resets (1 set a neural context in terms of narrow band frequencies that uniquely characterizes the activated circuits, (2 impose coherent low frequency phases to which high frequency activations can synchronize, identifiable as cross-frequency correlations across large anatomical distances, (3 are critical for neural coding models that depend on phase, increasing the informational content of neural representations, and (4 likely originate from the dynamics of canonical E-I circuits that are anatomically ubiquitous. These multiple signatures of phase resets are directly linked to enhanced information transfer and behavioral success. We survey how phase resets re-organize oscillations in diverse task contexts, including sensory perception, attentional stimulus selection, cross-modal integration, Pavlovian conditioning, and spatial navigation. The evidence we consider suggests that phase-resets can drive changes in neural excitability, ensemble organization, functional networks, and ultimately, overt behavior.

  18. Neuronal Alignment On Asymmetric Textured Surfaces

    CERN Document Server

    Beighley, Ross; Sekeroglu, Koray; Atherton, Timothy; Demirel, Melik C; Staii, Cristian

    2013-01-01

    Axonal growth and the formation of synaptic connections are key steps in the development of the nervous system. Here we present experimental and theoretical results on axonal growth and interconnectivity in order to elucidate some of the basic rules that neuronal cells use for functional connections with one another. We demonstrate that a unidirectional nanotextured surface can bias axonal growth. We perform a systematic investigation of neuronal processes on asymmetric surfaces and quantify the role that biomechanical surface cues play in neuronal growth. These results represent an important step towards engineering directed axonal growth for neuro-regeneration studies.

  19. Co-Development of Internalizing and Externalizing Problem Behaviors: Causal Direction and Common Vulnerability

    Science.gov (United States)

    Lee, Eunju J.; Bukowski, William M.

    2012-01-01

    Latent growth curve modeling was used to study the co-development of internalizing and externalizing problems in a sample of 2844 Korean fourth graders followed over four years. The project integrated two major theoretical viewpoints positing developmental mechanism: directional model and common vulnerability model. Findings suggest that (a) boys…

  20. Direct Labeling, Tester Expectancy and Delay Maintenance Behavior in Scottish Preschool Children.

    Science.gov (United States)

    Ritchie, Fiona K.; Toner, Ignatius J.

    1984-01-01

    Investigates the influence on Scottish preschool children's self-control of labels regarding patience given directly to the children themselves, and of the expectations regarding the children's patience provided to adult testers. Childrens self-control was assessed in a task in which each child's possession of accumulating candy rewards was made…

  1. Co-Development of Internalizing and Externalizing Problem Behaviors: Causal Direction and Common Vulnerability

    Science.gov (United States)

    Lee, Eunju J.; Bukowski, William M.

    2012-01-01

    Latent growth curve modeling was used to study the co-development of internalizing and externalizing problems in a sample of 2844 Korean fourth graders followed over four years. The project integrated two major theoretical viewpoints positing developmental mechanism: directional model and common vulnerability model. Findings suggest that (a) boys…

  2. Mapping Dimensionality and Directionality of Electronic Behavior in CeCoIn5: the Superconducting State

    Science.gov (United States)

    Feldman, Benjamin E.; Gyenis, Andras; Randeria, Mallika T.; Peterson, Gabriel A.; Aynajian, Pegor; Bauer, Eric D.; Yazdani, Ali

    Unconventional superconductors often exhibit anisotropic physical properties that arise from the directional dependence of their order parameters. A prime example is CeCoIn5, a heavy fermion d-wave superconductor with a rich low-temperature phase diagram consisting of competing and coexisting magnetic and superconducting orders. Here we present dilution refrigerator scanning tunneling microscopy of CeCoIn5 cleaved perpendicular to its basal plane. We study superconductivity on the (100) surface, whose normal vector points along the antinode of the superconducting energy gap. The gap magnitude is similar to that observed in the basal plane, with a key difference: it does not exhibit any suppression near step edges. Application of a magnetic field along the [100] direction leads to the formation of anisotropic vortices, and the vortex lattice undergoes a transition at high field before the superconducting state gives way to a pseudogap phase. Our measurements illustrate the directional dependence of the superconducting properties in CeCoIn5, and more generally, demonstrate the utility of imaging d-wave superconductors along their nodal and antinodal directions.

  3. Behavioral Synthesis of Asynchronous Circuits Using Syntax Directed Translation as Backend

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2009-01-01

    of syntax directed translation, and which allows the designer to perform automatic design space exploration guided by area or speed constraints. The paper presents an asynchronous implementation template consisting of a data-path and a control unit and its implementation using the asynchronous hardware...

  4. Towards behavioral synthesis of asynchronous circuits - an implementation template targeting syntax directed compilation

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard; Sparsø, Jens; Madsen, Jan

    2004-01-01

    domain by introducing a computation model, which resembles the synchronous datapath and control architecture, but which is completely asynchronous. The datapath and control architecture is then expressed in the Balsa-language, and using syntax directed compilation a corresponding handshake circuit...

  5. Direct and indirect predictors of social anxiety: The role of anxiety sensitivity, behavioral inhibition, experiential avoidance and self-consciousness.

    Science.gov (United States)

    Panayiotou, Georgia; Karekla, Maria; Panayiotou, Margarita

    2014-11-01

    Using mediated and moderated regression, this study examined the hypothesis that anxiety sensitivity, the tendency to be concerned about anxiety symptoms, and behavioral inhibition, the tendency to withdraw from novel and potentially dangerous stimuli, predict social anxiety indirectly through experiential avoidance as measured by the Acceptance and Action Questionnaire-II and self-consciousness, as measured by the Self-Consciousness Scale. Behavioral inhibition and anxiety sensitivity are operationalized as temperamental traits, while experiential avoidance and self-consciousness are seen as learned emotion regulation strategies. Study 1 included college student groups from Cyprus scoring high and low on social anxiety (N=64 and N=63) as measured by the Social Phobia and Anxiety Inventory. Study 2 examined a random community sample aged 18-65 (N=324) treating variables as continuous and using the Psychiatric Disorders Screening Questionnaire to screen for social anxiety. Results suggest that experiential avoidance, but not self-consciousness mediates the effects of anxiety sensitivity on predicting social anxiety status, but that behavioral inhibition predicts social anxiety directly and not through the proposed mediators. Moderation effects were not supported. Overall, the study finds that social anxiety symptomatology is predicted not only by behavioral inhibition, but also anxiety sensitivity, when individuals take actions to avoid anxious experiences. Modifying such avoidant coping approaches may be more beneficial for psychological treatments than attempts to change long-standing, temperamental personality traits.

  6. Cognitive-behavioral treatment of depression in men: tailoring treatment and directions for future research.

    Science.gov (United States)

    Spendelow, Jason S

    2015-03-01

    Depression is a significant public health issue and many researchers have suggested that modifications to conventional cognitive-behavioral therapy (CBT) are required to address infrequent help-seeking in men and counter negative effects of traditional masculinity on therapeutic engagement. This narrative review summarizes recommended alterations to CBT in the areas of therapeutic setting, process, and content. Key themes from this literature include a focus on behavioural interventions, and harmful cognitions that orginate from the traditional male gender stereotype. This literature is marked by limited empirical support for many of the recommended treatment modifications, and several options for future research are outlined. © The Author(s) 2014.

  7. Strongly directional and differential swimming behavior of an adult female white shark, Carcharodon carcharias (Chondrichthyes: Lamnidae from Guadalupe Island, Mexico

    Directory of Open Access Journals (Sweden)

    Ramón Bonfil

    2015-03-01

    Full Text Available We report on an adult female white shark tracked for 288 days and 7,100 km in the NE Pacific Ocean. The shark, tagged with a real-time satellite tag off Guadalupe Island, Mexico in October 2006, remained around the island for 3.5 months but left in early February 2007 for a ca. 3,900 km westward migration. Heading and swimming speed data showed that: a the arc-like route followed by this shark during oceanic travel involved strongly directional rapid movement, and b once the shark arrived to a specific (ca. 680 km wide area located 790 km north-northeast of the Hawaiian Islands, it switched into a distinct roaming behavior. The shark remained in this roaming area from late March to at least late July 2007. We show that real-time satellite tags can provide unique and valuable information about the migratory behavior of white sharks.

  8. HIGH-TEMPERATURE TENSILE FRACTURE BEHAVIOR OF DIRECTIONALLY SOLIDIFIED Ni,Cr,Al-TaC EUTECTIC SUPERALLOY

    Institute of Scientific and Technical Information of China (English)

    J.Zhang; J.J.Yu; H.Z.Fu

    2004-01-01

    The high-temperature tensile fracture behavior of the Ni, Cr, Al-TaC eutectic superalloy directionally solidified under high temperature gradient is investigated. The hightemperature tensile fracture of this in situ composite has ductile character with lots of ductile nests whose diameters decrease with the increasing solidification rates. The maximum σb and δ are respectively 668.5MPa and 19.6%. There is a TaC whisker in the center of each nest, and the deformation of γ' and TaC is uneven. The hightemperature tensile behavior cannot be explained by the rule of mixtures but is decided by the formation of the plastic deforrmation band. The crack extension model is given.

  9. Asymmetric interpersonal coupling in a cyclic sports-related movement task

    NARCIS (Netherlands)

    Meerhoff, Rens; De Poel, Harjo J.

    2014-01-01

    In interactive sports, teammates and/or opponents mutually tune their behavior. Expert performance thus implies certain interactive abilities, which critically depend on perceptual coupling. To illustrate this assertion, we examined the coordination dynamics with asymmetric interaction of dyads perf

  10. The actin regulators Enabled and Diaphanous direct distinct protrusive behaviors in different tissues during Drosophila development.

    Science.gov (United States)

    Nowotarski, Stephanie H; McKeon, Natalie; Moser, Rachel J; Peifer, Mark

    2014-10-15

    Actin-based protrusions are important for signaling and migration during development and homeostasis. Defining how different tissues in vivo craft diverse protrusive behaviors using the same genomic toolkit of actin regulators is a current challenge. The actin elongation factors Diaphanous and Enabled both promote barbed-end actin polymerization and can stimulate filopodia in cultured cells. However, redundancy in mammals and Diaphanous' role in cytokinesis limited analysis of whether and how they regulate protrusions during development. We used two tissues driving Drosophila dorsal closure--migratory leading-edge (LE) and nonmigratory amnioserosal (AS) cells--as models to define how cells shape distinct protrusions during morphogenesis. We found that nonmigratory AS cells produce filopodia that are morphologically and dynamically distinct from those of LE cells. We hypothesized that differing Enabled and/or Diaphanous activity drives these differences. Combining gain- and loss-of-function with quantitative approaches revealed that Diaphanous and Enabled each regulate filopodial behavior in vivo and defined a quantitative "fingerprint"--the protrusive profile--which our data suggest is characteristic of each actin regulator. Our data suggest that LE protrusiveness is primarily Enabled driven, whereas Diaphanous plays the primary role in the AS, and reveal each has roles in dorsal closure, but its robustness ensures timely completion in their absence.

  11. Single neurons in M1 and premotor cortex directly reflect behavioral interference.

    Directory of Open Access Journals (Sweden)

    Neta Zach

    Full Text Available Some motor tasks, if learned together, interfere with each other's consolidation and subsequent retention, whereas other tasks do not. Interfering tasks are said to employ the same internal model whereas noninterfering tasks use different models. The division of function among internal models, as well as their possible neural substrates, are not well understood. To investigate these questions, we compared responses of single cells in the primary motor cortex and premotor cortex of primates to interfering and noninterfering tasks. The interfering tasks were visuomotor rotation followed by opposing visuomotor rotation. The noninterfering tasks were visuomotor rotation followed by an arbitrary association task. Learning two noninterfering tasks led to the simultaneous formation of neural activity typical of both tasks, at the level of single neurons. In contrast, and in accordance with behavioral results, after learning two interfering tasks, only the second task was successfully reflected in motor cortical single cell activity. These results support the hypothesis that the representational capacity of motor cortical cells is the basis of behavioral interference and division between internal models.

  12. Direct ventral hippocampal-prefrontal input is required for anxiety-related neural activity and behavior

    Science.gov (United States)

    Padilla-Coreano, Nancy; Bolkan, Scott S.; Pierce, Georgia M.; Blackman, Dakota R.; Hardin, William D.; Garcia-Garcia, Alvaro L.; Spellman, Timothy J.; Gordon, Joshua A.

    2016-01-01

    The ventral hippocampus (vHPC), medial prefrontal cortex (mPFC), and basolateral amygdala (BLA) are each required for the expression of anxiety-like behavior. Yet the role of each individual element of the circuit is unclear. The projection from the vHPC to the mPFC has been implicated in anxiety-related neural synchrony and spatial representations of aversion. The role of this projection was examined using multi-site neural recordings combined with optogenetic terminal inhibition. Inhibition of vHPC input to the mPFC disrupted anxiety and mPFC representations of aversion, and reduced theta synchrony in a pathway-, frequency- and task-specific manner. Moreover, bilateral, but not unilateral inhibition altered physiological correlates of anxiety in the BLA, mimicking a safety-like state. These results reveal a specific role for the vHPC-mPFC projection in anxiety-related behavior and the spatial representation of aversive information within the mPFC. PMID:26853301

  13. Awareness, attitudes and behavior of hospital healthcare workers towards a mandatory vaccination directive: two years on.

    Science.gov (United States)

    Seale, Holly; Leask, Julie; Macintyre, C Raina

    2011-05-12

    In 2007, the state of New South Wales, Australia instituted a policy directive with compulsory provisions for health care workers to be vaccinated. This study sought to identify staff awareness and attitudes two years after it was implemented. It involved a self administered paper-based questionnaire of HCWs in two tertiary-referral teaching hospitals in Sydney, Australia in 2009. In the early phase, general awareness of the policy was incomplete and detailed knowledge was poor. However, support levels were high. Two years later, while the respondents indicated that they were aware that there was a policy in place, very few of the respondents were able to accurately describe its requirements. Regardless of the level of knowledge, support for the policy was still high (83% vs. 91%, respectively). Despite the high levels of general support for the vaccine policy directive in NSW, this study indicates that including influenza vaccination into the policy could be challenging.

  14. A Prefrontal-Hippocampal Comparator for Goal-Directed Behavior: The Intentional Self and Episodic Memory

    OpenAIRE

    Robert eNuman

    2015-01-01

    The hypothesis of this article is that the interactions between the prefrontal cortex and the hippocampus play a critical role in the modulation of goal-directed self-action and the strengthening of episodic memories. We describe various theories that model a comparator function for the hippocampus, and then elaborate the empirical evidence that supports these theories. One theory which describes a prefrontal-hippocampal comparator for voluntary action is emphasized. Action plans are essentia...

  15. A selective androgen receptor modulator enhances male-directed sexual preference, proceptive behavior, and lordosis behavior in sexually experienced, but not sexually naive, female rats.

    Science.gov (United States)

    Kudwa, A E; López, F J; McGivern, R F; Handa, R J

    2010-06-01

    Androgens influence many aspects of reproductive behavior, including sexual preference of females for males. In oophorectomized women with sexual desire disorder, testosterone patches improve libido, but their use is limited because of adverse side effects. Selective androgen receptor modulators offer an improved safety profile for both sexes: enhancing libido and muscle and bone growth in a manner similar to steroidal androgens but with fewer adverse effects, such as hirsutism, acne, and prostate growth. The current study investigated the action of a novel selective androgen receptor modulator (LGD-3303 [9-chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoroethyl)-3H-pyrrolo-[3,2-f]quinolin-7(6H)-one]) on male-directed sexual preference, proceptivity, and lordosis behavior of female rats. LGD-3303 is a nonsteroidal, nonaromatizable, highly selective ligand for the androgen receptor and effectively crosses the blood-brain barrier. Gonadectomized female rats were treated with LGD-3303 (3-30 mg/kg) or vehicle by daily oral gavage. Results showed that LGD-3303 treatment enhanced sexual preference of females for males but only if females had previous sexual experience. This occurred after 1 or 7 d of treatment. In contrast, preference for males was inhibited by LGD-3303 treatments of sexually naive females. The LGD-3303 increase in male preference was blocked by pretreatment with the androgen receptor antagonist flutamide. LGD-3303 treatment increased lordosis and proceptivity behaviors in ovariectomized females primed with suboptimal doses of estradiol benzoate plus progesterone. These data support the concept that LGD-3303 can stimulate aspects of female sexual behavior and may serve as a potential therapeutic for women with sexual desire disorders.

  16. Does non-monotonic behavior of directed flow signal the onset of deconfinement?

    CERN Document Server

    Nara, Yasushi

    2015-01-01

    We investigate the effects of nuclear mean-field as well as the formation and decay of nuclear clusters on the directed flow $v_1$ in high energy nucleus-nucleus collisions from $\\sqrt{s_{NN}}=7.7$ GeV to 27 GeV incident energies within a transport model. Specifically, we use the JAM transport model in which potentials are implemented based on the framework of the relativistic quantum molecular dynamics. Our approach reproduces the rapidity dependence of directed flow data up to $\\sqrt{s_{NN}}\\approx 8$ GeV showing the significant importance of mean-field. However, the slopes of $dv_1/dy$ at mid-rapidity are calculated to be positive at $\\sqrt{s_{NN}}=11.7$ and 19.6 GeV, and becomes negative above 27 GeV. Thus the result from the JAM hadronic transport model with nuclear mean-field approach is incompatible with the data. Therefore within our approach, we conclude that the excitation function of the directed flow cannot be explained by the hadronic degree of freedom alone.

  17. Does non-monotonic behavior of directed flow signal the onset of deconfinement?

    Science.gov (United States)

    Nara, Yasushi; Ohnishi, Akira

    2016-12-01

    We investigate the effects of nuclear mean-field as well as the formation and decay of nuclear clusters on the directed flow v1 in high energy nucleus-nucleus collisions from √{sNN} = 7.7 GeV to 27 GeV incident energies within a transport model. Specifically, we use the JAM transport model in which potentials are implemented based on the framework of the relativistic quantum molecular dynamics. Our approach reproduces the rapidity dependence of directed flow data up to √{sNN} ≈ 8 GeV showing the significant importance of mean-field. However, the slopes of dv1 / dy at mid-rapidity are calculated to be positive at √{sNN} 11.7 and 19.6 GeV, and become negative above 27 GeV. Thus the result from the JAM hadronic transport model with nuclear mean-field approach is incompatible with the data. Therefore within our approach, we conclude that the excitation function of the directed flow cannot be explained by the hadronic degree of freedom alone.

  18. Directional biases reveal utilization of arm's biomechanical properties for optimization of motor behavior.

    Science.gov (United States)

    Goble, Jacob A; Zhang, Yanxin; Shimansky, Yury; Sharma, Siddharth; Dounskaia, Natalia V

    2007-09-01

    Strategies used by the CNS to optimize arm movements in terms of speed, accuracy, and resistance to fatigue remain largely unknown. A hypothesis is studied that the CNS exploits biomechanical properties of multijoint limbs to increase efficiency of movement control. To test this notion, a novel free-stroke drawing task was used that instructs subjects to make straight strokes in as many different directions as possible in the horizontal plane through rotations of the elbow and shoulder joints. Despite explicit instructions to distribute strokes uniformly, subjects showed biases to move in specific directions. These biases were associated with a tendency to perform movements that included active motion at one joint and largely passive motion at the other joint, revealing a tendency to minimize intervention of muscle torque for regulation of the effect of interaction torque. Other biomechanical factors, such as inertial resistance and kinematic manipulability, were unable to adequately account for these significant biases. Also, minimizations of jerk, muscle torque change, and sum of squared muscle torque were analyzed; however, these cost functions failed to explain the observed directional biases. Collectively, these results suggest that knowledge of biomechanical cost functions regarding interaction torque (IT) regulation is available to the control system. This knowledge may be used to evaluate potential movements and to select movement of "low cost." The preference to reduce active regulation of interaction torque suggests that, in addition to muscle energy, the criterion for movement cost may include neural activity required for movement control.

  19. Contexts Paired with Junk Food Impair Goal-Directed Behavior in Rats: Implications for Decision Making in Obesogenic Environments.

    Science.gov (United States)

    Kendig, Michael D; Cheung, Ambrose M K; Raymond, Joel S; Corbit, Laura H

    2016-01-01

    The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behavior. In Experiment 1, adult male rats received exposures to one context containing three "junk" foods (JFs context) and another containing chow (Chow context). Next, rats were food-deprived and trained to perform instrumental responses (lever-press) for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behavior were then assessed by outcome devaluation tests held in the JF, chow and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behavior when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation) when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behavior, but that this deficit was improved by

  20. Contexts Paired with Junk Food Impair Goal-Directed Behavior in Rats: Implications for Decision Making in Obesogenic Environments

    Science.gov (United States)

    Kendig, Michael D.; Cheung, Ambrose M. K.; Raymond, Joel S.; Corbit, Laura H.

    2016-01-01

    The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behavior. In Experiment 1, adult male rats received exposures to one context containing three “junk” foods (JFs context) and another containing chow (Chow context). Next, rats were food-deprived and trained to perform instrumental responses (lever-press) for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behavior were then assessed by outcome devaluation tests held in the JF, chow and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behavior when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation) when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behavior, but that this deficit was improved

  1. Dynamic behavior of a direct expansion evaporator under frosting condition. Part II. Field investigation on a shipping container

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore 634798 (Singapore). School of Mechanical and Aerospace Engineering

    2006-06-15

    A field investigation is performed on the frost formation at an evaporator of a commercial full-scale refrigerated container that uses R-12 as the working refrigerant. Results when compared with those from a numerical model presented earlier show that the model is capable of predicting the dynamic behavior of a direct expansion evaporator under both non-frosting and frosting conditions. The air outlet and energy transferred compare well between experiment and model, and within 20% for the air pressure drop. The frost occurrence and propagation agree well generally, with the frost formation first occurring at the first row where the refrigerant enters the evaporator. (author)

  2. Correspondence behavior of classical and quantum dissipative directed transport via thermal noise

    Science.gov (United States)

    Carlo, Gabriel G.; Ermann, Leonardo; Rivas, Alejandro M. F.; Spina, María E.

    2016-04-01

    We systematically study several classical-quantum correspondence properties of the dissipative modified kicked rotator, a paradigmatic ratchet model. We explore the behavior of the asymptotic currents for finite ℏeff values in a wide range of the parameter space. We find that the correspondence between the classical currents with thermal noise providing fluctuations of size ℏeff and the quantum ones without it is very good in general with the exception of specific regions. We systematically consider the spectra of the corresponding classical Perron-Frobenius operators and quantum superoperators. By means of an average distance between the classical and quantum sets of eigenvalues we find that the correspondence is unexpectedly quite uniform. This apparent contradiction is solved with the help of the Weyl-Wigner distributions of the equilibrium eigenvectors, which reveal the key role of quantum effects by showing surviving coherences in the asymptotic states.

  3. Dynamic behavior of a direct expansion evaporator under frosting condition. Part I. Distributed model

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore 634798 (Singapore). School of Mechanical and Aerospace Engineering

    2006-06-15

    A general distributed model with two-phase flow for refrigerant coupled with a frost model is developed for studying the dynamic behavior of an evaporator. The equations are derived in non-steady-state manner for the refrigerant and a quasi-steady state model with permeation for the frost. The complex flow and geometry of the finned tube evaporator lead to uneven wall and air temperature distributions, which in turn affect the rate of frost growth and densification along the coil depth. Results include frost accumulation and its effect on energy transfer, air off-coil temperature, refrigerant liquid dry-out position and propagation of frost formation along the coil. (author)

  4. Asymmetric nanoparticle may go "active" at room temperature

    Science.gov (United States)

    Sheng, Nan; Tu, YuSong; Guo, Pan; Wan, RongZheng; Wang, ZuoWei; Fang, HaiPing

    2017-04-01

    Using molecular dynamics simulations, we show that an asymmetrically shaped nanoparticle in dilute solution possesses a spontaneously curved trajectory within a finite time interval, instead of the generally expected random walk. This unexpected dynamic behavior has a similarity to that of active matters, such as swimming bacteria, cells, or even fish, but is of a different physical origin. The key to the curved trajectory lies in the non-zero resultant force originated from the imbalance of the collision forces acted by surrounding solvent molecules on the asymmetrically shaped nanoparticle during its orientation regulation. Theoretical formulae based on microscopic observations have been derived to describe this non-zero force and the resulting motion of the asymmetrically shaped nanoparticle.

  5. Asymmetric gravity jitter excited slosh waves at a liquid-vapor-solid interface in microgravity

    Science.gov (United States)

    Hung, R. J.; Pan, H. L.; Leslie, F. W.

    1992-01-01

    The dynamical behavior of fluids affected by the asymmetric gravity jitter oscillations is investigated focusing on the surface tension effect on partially filled rotating fluids in a sub-scale gravity probe-B spacecraft propellant dewar tank. Data obtained revealed that the lower frequency gravity jitter imposed on the time-dependent variations of the background gravity direction induced a greater amplitude of oscillations and a stronger degree of asymmetry in liquid-vapor interface geometry than that caused by the higher frequency gravity jitter. It is also found that the greater the components of background gravity in radial and circumferential directions the greater the contribution to driving more toward increasing amplitude and degrees of asymmetry of the liquid-vapor interface profiles, which in turn modify the disturbance of moment of inertia and angular momentum of spacecraft.

  6. Antiepileptic drugs prescription utilization behavior and direct costs of treatment in a national hospital of India

    Directory of Open Access Journals (Sweden)

    Ahsan Haroon

    2012-01-01

    Full Text Available Background and Objectives: The present study evaluated the direct costs of active epilepsy and looked at the pattern of drug prescription and utilization in epileptic patients visiting the neuroscience centre of a national hospital of India. Materials and Methods: A total of 134 epileptic patients were studied over a period of 4 months. Patients demography, commonly prescribed antiepileptic drugs (AEDs, socioeconomic status, direct costs, response ratio (RR for newer drugs, and quality of life (QOLIE-10 was evaluated. Results and Discussion: We found a higher percentage of male patients (67.9% as compared with females. Most of the patients were in the age group 11-30 years and majority of them (39.6% belonged to lower middle group. A higher percentage (68.7 of drugs was prescribed as polytherapy. Higher monthly cost was observed for some of the newer AEDs including the lamotrigine, levetiracetam, and lacosamide as compared with older drugs. Among the newer drugs, clobazam had the lowest cost. RR was calculated for 12 patients out of which 8 had a RR < −0.50. The QOL domains, following conventional or newer drugs, were not much affected. Conclusion: The study indicates an increasing trend toward clinical usage of newer AEDs, increasing trend of poly-therapy with significant escalations in the cost of therapy.

  7. Asymptotic Behavior of an Artificial Neural Network Defined on Multipartite Directed Graph

    Directory of Open Access Journals (Sweden)

    N. C. Majee

    2010-01-01

    Full Text Available Problem statement: Artificial Neural Network (ANN are simple models to mimic some essential features of the complex central nervous system. ANN models are realistic due to their inherent stochastic nature of neural computation and strong synchronicity. Different ANN models are associated with directed and signed graphs. The present study proceeded by relaxing certain simplifying assumptions in the ANN model. Approach: It was assumed that the connected graph associated with the ANN is a multipartite directed graph whose connection comprising of four blocks and two blocks are either both symmetric or both anti symmetric. The convergence of such network was studied in the present research with the help of Lyapunov functional. Results: Attractors (fixed points of such ANN and also limit cycles of different orders are investigated. Bounds of transient length of the neural network were also calculated. Numerical simulation in support of the results was also depicted. Conclusion: It was shown that under synchronous updating rule such networks converge to a fixed point or to a limit cycle of period 2 or 4. The bound of transient length was discussed. Conclusions were drawn from the simulation studies carried out in support of the results.

  8. Analyzing and modeling the dynamic thermal behaviors of direct contact condensers packed with PCM spheres

    Science.gov (United States)

    Wang, Kai; Hu, Tao; Hassabou, Abdel H.; Spinnler, Markus; Polifke, Wolfgang

    2013-01-01

    Condensers serve as important components for humidification-dehumidification (HDH) desalination plants. Based on the interpenetration continua approach with volume averaging technique, a mathematical dynamic model for analyzing the heat and mass transfer within direct contact condensers with co-current or countercurrent flow arrangement was developed. It was validated against the experimental data from a small scale HDH desalination system. Comparisons including the productivities and the temperature profiles of gas, liquid, and solid phases show good agreement with the measurements. Phase change material (PCM) melting processes have little effect on water production rate for co-current flow arrangement, but the condenser packed with PCM capsules have higher water production rates than that packed with air capsules packed under given conditions. The relative humidity profile of the bulk gas shows contrary trend with the gas temperature profile. The direct contact condenser with countercurrent flow arrangement can provide much better heat and mass transfer between gas and water and produce about 16.3% more fresh water than the same condenser with co-current flow arrangement in 4 h under given conditions.

  9. Asymmetric distances for binary embeddings.

    Science.gov (United States)

    Gordo, Albert; Perronnin, Florent; Gong, Yunchao; Lazebnik, Svetlana

    2014-01-01

    In large-scale query-by-example retrieval, embedding image signatures in a binary space offers two benefits: data compression and search efficiency. While most embedding algorithms binarize both query and database signatures, it has been noted that this is not strictly a requirement. Indeed, asymmetric schemes that binarize the database signatures but not the query still enjoy the same two benefits but may provide superior accuracy. In this work, we propose two general asymmetric distances that are applicable to a wide variety of embedding techniques including locality sensitive hashing (LSH), locality sensitive binary codes (LSBC), spectral hashing (SH), PCA embedding (PCAE), PCAE with random rotations (PCAE-RR), and PCAE with iterative quantization (PCAE-ITQ). We experiment on four public benchmarks containing up to 1M images and show that the proposed asymmetric distances consistently lead to large improvements over the symmetric Hamming distance for all binary embedding techniques.

  10. Nonlinear effects in asymmetric catalysis.

    Science.gov (United States)

    Satyanarayana, Tummanapalli; Abraham, Susan; Kagan, Henri B

    2009-01-01

    There is a need for the preparation of enantiomerically pure compounds for various applications. An efficient approach to achieve this goal is asymmetric catalysis. The chiral catalyst is usually prepared from a chiral auxiliary, which itself is derived from a natural product or by resolution of a racemic precursor. The use of non-enantiopure chiral auxiliaries in asymmetric catalysis seems unattractive to preparative chemists, since the anticipated enantiomeric excess (ee) of the reaction product should be proportional to the ee value of the chiral auxiliary (linearity). In fact, some deviation from linearity may arise. Such nonlinear effects can be rich in mechanistic information and can be synthetically useful (asymmetric amplification). This Review documents the advances made during the last decade in the use of nonlinear effects in the area of organometallic and organic catalysis.

  11. Constitutive Cyclic Deformation Behavior in Single-crystal and Directionally Solidified SSME High-pressure Fuel Turbopump Airfoil Materials

    Science.gov (United States)

    Milligan, W. W.; Huron, E. S.; Antolovich, S. D.

    1985-01-01

    The major goal of the project is to correlate mechanical properties with microstructural deformation behavior and to develop models for constitutive response under a variety of monotonic and cyclic loading cycles, temperatures, strain levels, strain rates, and environments. Two alloys are being studied as candidate SSME turbine blade materials. The first is PWA 1480, which is a single-crystal alloy whose nominal composition is reported. The second alloy being studied is D.S. Mar-M 246 + Hf. This is a directionally solidified material, and its nominal composition is also reported. The major areas of interest for the two materials will be slightly different. The single-crystal alloy lends itself well to fundamental deformation studies, since resolved shear stresses on slip planes are all known and only one grain is present. The D.S. material presents an excellent opportunity to study the effects of slightly misaligned grains on deformation behavior. The two materials will be studied by using approximately the same test matrix, so a good degree of direct comparison will also be possible.

  12. Optical recoil of asymmetric nano-optical antenna.

    Science.gov (United States)

    Song, Jung-Hwan; Shin, Jonghwa; Lim, Hee-Jin; Lee, Yong-Hee

    2011-08-01

    We propose nano-optical antennas with asymmetric radiation patterns as light-driven mechanical recoil force generators. Directional antennas are found to generate recoil force efficiently when driven in the spectral proximity of their resonances. It is also shown that the recoil force is equivalent to the Poynting vector integrated over a closed sphere containing the antenna structures.

  13. Adoption subsidy versus technology standards under asymmetric information

    NARCIS (Netherlands)

    I.V. Ossokina (Ioulia); O.H. Swank (Otto)

    2008-01-01

    textabstractMarket-based instruments are believed to create more efficient incentives for firms to adopt new technologies than command-and-control policies. We compare the effects of a direct technology regulation and of an adoption subsidy under asymmetric information about the costs of technologic

  14. Asymmetric Wave Transmission During Electron-Cyclotron Resonant Heating

    NARCIS (Netherlands)

    Peeters, A.G.; Smits, F. M. A.; Giruzzi, G.; Oomens, A. A. M.; Westerhof, E.

    1995-01-01

    In low density plasmas in the RTP tokamak the single-pass absorption of O-mode waves at the fundamental electron cyclotron resonance is observed to be toroidally asymmetric. The absorption is highest for waves travelling in the direction opposite to the toroidal plasma current. Fokker-Planck

  15. Direct visualization of the thermomagnetic behavior of pseudo–single-domain magnetite particles

    Science.gov (United States)

    Almeida, Trevor P.; Muxworthy, Adrian R.; Kovács, András; Williams, Wyn; Brown, Paul D.; Dunin-Borkowski, Rafal E.

    2016-01-01

    The study of the paleomagnetic signal recorded by rocks allows scientists to understand Earth’s past magnetic field and the formation of the geodynamo. The magnetic recording fidelity of this signal is dependent on the magnetic domain state it adopts. The most prevalent example found in nature is the pseudo–single-domain (PSD) structure, yet its recording fidelity is poorly understood. Here, the thermoremanent behavior of PSD magnetite (Fe3O4) particles, which dominate the magnetic signatures of many rock lithologies, is investigated using electron holography. This study provides spatially resolved magnetic information from individual Fe3O4 grains as a function of temperature, which has been previously inaccessible. A small exemplar Fe3O4 grain (~150 nm) exhibits dynamic movement of its magnetic vortex structure above 400°C, recovering its original state upon cooling, whereas a larger exemplar Fe3O4 grain (~250 nm) is shown to retain its vortex state on heating to 550°C, close to the Curie temperature of 580°C. Hence, we demonstrate that Fe3O4 grains containing vortex structures are indeed reliable recorders of paleodirectional and paleointensity information, and the presence of PSD magnetic signals does not preclude the successful recovery of paleomagnetic signals. PMID:27152353

  16. Direct visualization of the thermomagnetic behavior of pseudo-single-domain magnetite particles.

    Science.gov (United States)

    Almeida, Trevor P; Muxworthy, Adrian R; Kovács, András; Williams, Wyn; Brown, Paul D; Dunin-Borkowski, Rafal E

    2016-04-01

    The study of the paleomagnetic signal recorded by rocks allows scientists to understand Earth's past magnetic field and the formation of the geodynamo. The magnetic recording fidelity of this signal is dependent on the magnetic domain state it adopts. The most prevalent example found in nature is the pseudo-single-domain (PSD) structure, yet its recording fidelity is poorly understood. Here, the thermoremanent behavior of PSD magnetite (Fe3O4) particles, which dominate the magnetic signatures of many rock lithologies, is investigated using electron holography. This study provides spatially resolved magnetic information from individual Fe3O4 grains as a function of temperature, which has been previously inaccessible. A small exemplar Fe3O4 grain (~150 nm) exhibits dynamic movement of its magnetic vortex structure above 400°C, recovering its original state upon cooling, whereas a larger exemplar Fe3O4 grain (~250 nm) is shown to retain its vortex state on heating to 550°C, close to the Curie temperature of 580°C. Hence, we demonstrate that Fe3O4 grains containing vortex structures are indeed reliable recorders of paleodirectional and paleointensity information, and the presence of PSD magnetic signals does not preclude the successful recovery of paleomagnetic signals.

  17. Microstructure, Fatigue Behavior, and Failure Mechanisms of Direct Laser-Deposited Inconel 718

    Science.gov (United States)

    Johnson, Alex S.; Shao, Shuai; Shamsaei, Nima; Thompson, Scott M.; Bian, Linkan

    2017-03-01

    Inconel 718 is considered to be a superalloy with a series of superior properties such as high strength, creep resistance, and corrosion resistance at room and elevated temperatures. Additive manufacturing (AM) is particularly appealing to Inconel 718 because of its near-net-shape production capability for circumventing the poor machinability of this superalloy. Nevertheless, AM parts are prone to porosity, which is detrimental to their fatigue resistance. Thus, further understanding of their fatigue behavior is required before their widespread use in load-bearing applications. In this work, the microstructure and fatigue properties of AM Inconel 718, produced in a Laser Engineered Net Shaping (LENS™) system and heat treated with a standard heat treatment schedule, are evaluated at room temperature. Fully reversed strain controlled fatigue tests were performed on cylindrical specimens with straight gage sections at strain amplitudes ranging from 0.001 mm/mm to 0.01 mm/mm. The fracture surfaces of fatigue specimens were inspected with a scanning electron microscope. The results indicate that the employed heat treatment allowed the large, elongated grains and dendritic structure of the as-built material to break down into smaller, equiaxed grains, with some dendritic structures remaining between layers. The AM specimens were found to possess lower fatigue resistance than wrought Inconel 718, and this is primarily attributed to the presence of brittle metal-carbide/oxide inclusions or pores near their surface.

  18. Young driver distraction: state of the evidence and directions for behavior change programs.

    Science.gov (United States)

    Buckley, Lisa; Chapman, Rebekah L; Sheehan, Mary

    2014-05-01

    Adolescent drivers are overrepresented in distraction-related motor vehicle crashes. A number of potential reasons for such an elevated risk include driving inexperience, high adoption of communication technology, increased peer involvement, and tendency to take risks, which render young drivers particularly vulnerable. Major legislative efforts in Graduated Licensing Systems that include passenger restrictions have shown positive effects. Restrictions on cell phone use are also being introduced; however, it is challenging to enforce such regulations. This article argues that such contextual, legislative interventions are an essential prevention strategy, but there is an unfilled need to introduce behavior change programs that may target adolescents, parents, and friends. A theoretical framework is applied in which risk and protective factors are identified from research within the contexts of community and jurisdiction. In the literature on distraction, social context and normative influences are key elements used to inform program design for adolescent drivers, with parental monitoring informing interventions targeting parents. Following from this assessment of the message content assessment, the design of strategies to deliver the messages is reviewed. In the current literature, school-based programs, simulations, and Web-delivered programs have been evaluated with supplementary strategies delivered by physicians and parents. Such developments are still at an early stage of development, and ultimately will need controlled implementation and evaluation studies. Of course, there is no likely single approach to prevent adolescent driver distraction. Complementary approaches such as the further development of technological interventions to manage phone use are needed.

  19. Microstructure, Fatigue Behavior, and Failure Mechanisms of Direct Laser-Deposited Inconel 718

    Science.gov (United States)

    Johnson, Alex S.; Shao, Shuai; Shamsaei, Nima; Thompson, Scott M.; Bian, Linkan

    2016-12-01

    Inconel 718 is considered to be a superalloy with a series of superior properties such as high strength, creep resistance, and corrosion resistance at room and elevated temperatures. Additive manufacturing (AM) is particularly appealing to Inconel 718 because of its near-net-shape production capability for circumventing the poor machinability of this superalloy. Nevertheless, AM parts are prone to porosity, which is detrimental to their fatigue resistance. Thus, further understanding of their fatigue behavior is required before their widespread use in load-bearing applications. In this work, the microstructure and fatigue properties of AM Inconel 718, produced in a Laser Engineered Net Shaping (LENS™) system and heat treated with a standard heat treatment schedule, are evaluated at room temperature. Fully reversed strain controlled fatigue tests were performed on cylindrical specimens with straight gage sections at strain amplitudes ranging from 0.001 mm/mm to 0.01 mm/mm. The fracture surfaces of fatigue specimens were inspected with a scanning electron microscope. The results indicate that the employed heat treatment allowed the large, elongated grains and dendritic structure of the as-built material to break down into smaller, equiaxed grains, with some dendritic structures remaining between layers. The AM specimens were found to possess lower fatigue resistance than wrought Inconel 718, and this is primarily attributed to the presence of brittle metal-carbide/oxide inclusions or pores near their surface.

  20. Shared values and organizational citizenship behavior of generational cohorts: A review and future directions

    Directory of Open Access Journals (Sweden)

    I. Yogamalar

    2016-12-01

    Full Text Available The literature implies that in the contemporary workforce, one of the interesting and challenging tasks of the management is to effectively handle different generations who possess various value systems. Hence, the foremost aspiration of the current study is to present the empirical evidence on the diverse characteristics and values of generational cohorts; the interests of HR specialists, managers and researchers in dealing with multigenerational workforce and their impact on work-related outcomes, the responsibility of management; the influence of values on behavior (especially, in-role and extra-role behaviours and various positive outcomes to employees and organizations. This article also reviewed the previous studies related to shared values or P-O fit, OCB and highlighted that very little research was conducted in academic institutions. This study shows the generational categories from the Western context and the Indian context. It also intends to identify the gaps in the generational research and pave the way for further investigation. Finally, based on the research gaps identified, this article suggests and discusses the importance of generational difference on shared values and OCB in academic field in the Indian context as well as reframes the list of shared values from academic perspective for further investigation. Moreover, academic field is one of the predominant workplaces where intergenerational communication is at a high rate. Thus, the more attention needs to be given to the behaviours of generational cohorts in order to attain the goal of the institution.

  1. The origin of EL2 family evidenced by STM direct observations of individual photoquenching behaviors

    Science.gov (United States)

    Hida, Akira; Mera, Yutaka; Maeda, Koji

    2003-12-01

    Abundant point defects in low-temperature grown (LT-) GaAs, presumably As antisite defects, exhibit a photo-induced transformation at low temperatures with an excitation spectrum very close to that obtained for the macroscopic photoquenching effect of EL2 centers. Some of the defects do not exhibit the photo-induced transformation, disfavoring the hypothesis of variants of EL2-like centers differing in the atomic structures. The unquenchable EL2 centers are commonly located near the interface between the LT-GaAs epi-layer and the n-GaAs substrate. Separate macroscopic photoluminescence experiments showed that the photoquenching efficiency is strongly decreased by external compressive stress, which suggests that the absence of the phototransformation behavior in some centers was due to a local stress field induced by the lattice mismatch between the epi-layer and the substrate. This is shown by STM-electric field modulation spectroscopy that the epi-layer was locally strained to a different degree depending on the position from the interface. Therefore, we conclude that the EL2 variants are the result of the spatial variation of the internal stress environment that is felt by the EL2 centers in an identical atomic structure.

  2. The origin of EL2 family evidenced by STM direct observations of individual photoquenching behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Hida, Akira; Mera, Yutaka; Maeda, Koji

    2003-12-31

    Abundant point defects in low-temperature grown (LT-) GaAs, presumably As antisite defects, exhibit a photo-induced transformation at low temperatures with an excitation spectrum very close to that obtained for the macroscopic photoquenching effect of EL2 centers. Some of the defects do not exhibit the photo-induced transformation, disfavoring the hypothesis of variants of EL2-like centers differing in the atomic structures. The unquenchable EL2 centers are commonly located near the interface between the LT-GaAs epi-layer and the n-GaAs substrate. Separate macroscopic photoluminescence experiments showed that the photoquenching efficiency is strongly decreased by external compressive stress, which suggests that the absence of the phototransformation behavior in some centers was due to a local stress field induced by the lattice mismatch between the epi-layer and the substrate. This is shown by STM-electric field modulation spectroscopy that the epi-layer was locally strained to a different degree depending on the position from the interface. Therefore, we conclude that the EL2 variants are the result of the spatial variation of the internal stress environment that is felt by the EL2 centers in an identical atomic structure.

  3. Space Charge Behavior in Paper Insulation Induced by Copper Sulfide in High-Voltage Direct Current Power Transformers

    Directory of Open Access Journals (Sweden)

    Ruijin Liao

    2015-08-01

    Full Text Available The main insulation system in high-voltage direct current (HVDC transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper presents the space charge behavior in insulation paper induced by copper sulfide generated by corrosive sulfur in insulation oil. Thermal aging tests of paper-wrapped copper strip called the pigtail model were conducted at 130 °C in laboratory. Scanning electron microscopy (SEM was used to observe the surface of copper and paper. Pulse electroacoustic (PEA and thermally stimulated current (TSC methods were used to obtain the space charge behavior in paper. Results showed that both maximum and total amount of space charge increased for the insulation paper contaminated by semi-conductor chemical substance copper sulfide. The space charge decay rate of contaminated paper was significantly enhanced after the polarization voltage was removed. The TSC results revealed that copper sulfide increased the trap density and lowered the shallow trap energy levels. These results contributed to charge transportation by de-trapping and trapping processes. This improved charge transportation could be the main reason for the decreased breakdown voltage of paper insulation material.

  4. Individual Differences in Participations of a Brand Community: A Validation of the Goal-Directed Behavior Model

    Directory of Open Access Journals (Sweden)

    Badri Munir Sukoco

    2011-10-01

    Full Text Available Previous studies have been neglected the behavior of the owners who are non-members when discussing brand community (BC, even though they are substantially larger. This study purposely discuss what are the differences between the two by using model of goal directed behavior (MGB and uses the findings as a way to recruit non-members in BC activities. This study also proposes some refinements to the original concept of MGB. This survey-based study, conducted with 201 active members and 226 non-members of a motor club in Indonesia, employs structural equation modeling methodology which supports the proposed model. The findings suggest that non-members have a stronger effect of positive anticipated emotions on attitude and desire to participate, which could be the starting point for marketers to recruit them. While for non-members, the perceived behavioral control and attitude toward BC activities have greater effects. The findings and discussion lead to some managerial and research implications.

  5. Factors influencing consumers' attitudinal and behavioral responses to direct-to-consumer and over-the-counter drug advertising.

    Science.gov (United States)

    Lee, Mina; Whitehill King, Karen; Reid, Leonard N

    2015-04-01

    Using a model developed from the research literature, the authors compared consumers' attitudinal and behavioral responses to direct-to-consumer prescription drug advertising (DCTA) and over-the-counter nonprescription drug advertising (OTCA) of drugs. Adults 18 years of age and older who had taken any prescription drugs in the past 6 months completed online survey questionnaires. Variables measured included demographics (age, gender, race, education, and income), health-related characteristics (health status, prescription and over-the-counter drug use, health consciousness, and involvement with prescription or over-the-counter drugs), perceived amount of attention and exposure to DTCA and OTCA, attitudinal outcomes (skepticism toward DTCA/OTCA and attitude toward DTCA/OTCA), and behavioral outcomes triggered by DTCA and OTCA. The findings indicate that exposure to drug advertising is one of the most significant predictors of attitudinal and behavioral outcomes. Some audience factors such as health status, involvement with drugs, health consciousness, drug use, income, and age also were differentially associated with consumer responses to drug advertising.

  6. Experimental and theoretical study on spray behaviors of modified bio-ethanol fuel employing direct injection system

    Directory of Open Access Journals (Sweden)

    Ghahremani Amirreza

    2017-01-01

    Full Text Available One of the key solutions to improve engine performance and reduce exhaust emissions of internal combustion engines is direct injection of bio-fuels. A new modified bio-ethanol is produced to be substituted by fossil fuels in gasoline direct injection engines. The key advantages of modified bio-ethanol fuel as an alternative fuel are higher octane number and oxygen content, a long-chain hydro-carbon fuel, and lower emissions compared to fossil fuels. In the present study spray properties of a modified bio-ethanol and its atomization behaviors have been studied experimentally and theoretically. Based on atomization physics of droplets dimensional analysis has been performed to develop a new non-dimensional number namely atomization index. This number determines the atomization level of the spray. Applying quasi-steady jet theory, air entrainment and fuel-air mixing studies have been performed. The spray atomization behaviors such as atomization index number, Ohnesorge number, and Sauter mean diameter have been investigated employing atomization model. The influences of injection and ambient conditions on spray properties of different blends of modified bio-ethanol and gasoline fuels have been investigated performing high-speed visualization technique. Results indicate that decreasing the difference of injection and ambient pressures increases spray cone angle and projected area, and decreases spray tip penetration length. As expected, increasing injection pressure improves atomization behaviors of the spray. Increasing percentage of modified bio-ethanol in the blend, increases spray tip penetration and decreases the projected area as well.

  7. Asymmetric Synthesis via Chiral Aziridines

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Harden, Adrian; Wyatt, Paul

    1996-01-01

    A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the b......A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines...

  8. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  9. Applying the Model of Goal-Directed Behavior, Including Descriptive Norms, to Physical Activity Intentions: A Contribution to Improving the Theory of Planned Behavior.

    Science.gov (United States)

    Esposito, Gabriele; van Bavel, René; Baranowski, Tom; Duch-Brown, Néstor

    2016-08-01

    The theory of planned behavior (TPB) has received its fair share of criticism lately, including calls for it to retire. We contribute to improving the theory by testing extensions such as the model of goal-directed behavior (MGDB, which adds desire and anticipated positive and negative emotions) applied to physical activity (PA) intention. We also test the inclusion of a descriptive norms construct as an addition to the subjective norms construct, also applied to PA, resulting in two additional models: TPB including descriptive norms (TPB + DN) and MGDB including descriptive norms (MGDB + DN). The study is based on an online survey of 400 young adult Internet users, previously enrolled in a subject pool. Confirmatory factor analysis (CFA) showed that TPB and TPB + DN were not fit for purpose, while MGDB and MGDB + DN were. Structural equation modelling (SEM) conducted on MGDB and MGDB + DN showed that the inclusion of descriptive norms took over the significance of injunctive norms, and increased the model's account of total variance in intention to be physically active.

  10. An investigation of the generalizability and dependability of direct behavior rating single item scales (DBR-SIS) to measure academic engagement and disruptive behavior of middle school students.

    Science.gov (United States)

    Chafouleas, Sandra M; Briesch, Amy M; Riley-Tillman, T Chris; Christ, Theodore J; Black, Anne C; Kilgus, Stephen P

    2010-06-01

    A total of 4 raters, including 2 teachers and 2 research assistants, used Direct Behavior Rating Single Item Scales (DBR-SIS) to measure the academic engagement and disruptive behavior of 7 middle school students across multiple occasions. Generalizability study results for the full model revealed modest to large magnitudes of variance associated with persons (students), occasions of measurement (day), and associated interactions. However, an unexpectedly low proportion of the variance in DBR data was attributable to the facet of rater, as well as a negligible variance component for the facet of rating occasion nested within day (10-min interval within a class period). Results of a reduced model and subsequent decision studies specific to individual rater and rater type (research assistant and teacher) suggested degree of reliability-like estimates differed substantially depending on rater. Overall, findings supported previous recommendations that in the absence of estimates of rater reliability and firm recommendations regarding rater training, ratings obtained from DBR-SIS, and subsequent analyses, be conducted within rater. Additionally, results suggested that when selecting a teacher rater, the person most likely to substantially interact with target students during the specified observation period may be the best choice.

  11. Asymmetric chemical reactions by polarized quantum beams

    Science.gov (United States)

    Takahashi, Jun-Ichi; Kobayashi, Kensei

    One of the most attractive hypothesis for the origin of homochirality in terrestrial bio-organic compounds (L-amino acid and D-sugar dominant) is nominated as "Cosmic Scenario"; a chiral impulse from asymmetric excitation sources in space triggered asymmetric reactions on the surfaces of such space materials as meteorites or interstellar dusts prior to the existence of terrestrial life. 1) Effective asymmetric excitation sources in space are proposed as polarized quantum beams, such as circularly polarized light and spin polarized electrons. Circularly polarized light is emitted as synchrotron radiation from tightly captured electrons by intense magnetic field around neutron stars. In this case, either left-or right-handed polarized light can be observed depending on the direction of observation. On the other hand, spin polarized electrons is emitted as beta-ray in beta decay from radioactive nuclei or neutron fireballs in supernova explosion. 2) The spin of beta-ray electrons is longitudinally polarized due to parity non-conservation in the weak interaction. The helicity (the the projection of the spin onto the direction of kinetic momentum) of beta-ray electrons is universally negative (left-handed). For the purpose of verifying the asymmetric structure emergence in bio-organic compounds by polarized quantum beams, we are now carrying out laboratory simulations using circularly polarized light from synchrotron radiation facility or spin polarized electron beam from beta-ray radiation source. 3,4) The target samples are solid film or aqueous solution of racemic amino acids. 1) K.Kobayashi, K.Kaneko, J.Takahashi, Y.Takano, in Astrobiology: from simple molecules to primitive life; Ed. V.Basiuk; American Scientific Publisher: Valencia, 2008. 2) G.A.Gusev, T.Saito, V.A.Tsarev, A.V.Uryson, Origins Life Evol. Biosphere. 37, 259 (2007). 3) J.Takahashi, H.Shinojima, M.Seyama, Y.Ueno, T.Kaneko, K.Kobayashi, H.Mita, M.Adachi, M.Hosaka, M.Katoh, Int. J. Mol. Sci. 10, 3044

  12. Direct relationship between osmotic and ionic conforming behavior and tissue water regulatory capacity in echinoids.

    Science.gov (United States)

    Santos, Ivonete A; Castellano, Giovanna C; Freire, Carolina A

    2013-03-01

    Echinoderms are considered marine osmoconforming invertebrates. However, many are intertidal or live next to estuaries, tolerating salinity changes and showing extracellular gradients to dilute seawater. Three species of echinoids - Lytechinus variegatus, which can occur next to estuarine areas, the rocky intertidal Echinometra lucunter, and the mostly subtidal Arbacia lixula - were submitted to a protocol of stepwise (rate of 2-3 psu/h) dilution, down to 15 psu, or concentration, up to 45 psu, of control seawater (35 psu). Coelomic fluid samples were obtained every hour. The seawater dilution experiment lasted 8h, while the seawater concentration experiment lasted 6h. Significant gradients (40-90% above value in 15 psu seawater) for osmolality, sodium, magnesium, and potassium were shown by L. variegatus and E. lucunter. A. lixula showed the smallest gradients, displaying the strongest conforming behavior. The esophagus of the three species was challenged in vitro with 20 and 50% osmotic shocks (hypo- and hyperosmotic). A. lixula, the most "conforming" species, showed the highest capacity to avoid swelling of its tissues upon the -50% hyposmotic shock, and was also the species less affected by salinity changes concerning the observation of spines and ambulacral feet movement in the whole-animal experiments. Thus, the most conforming species (A. lixula) displayed the highest capacity to regulate tissue water/volume, and was also the most euryhaline among the three studied species. In addition, tissues from all three species swelled much more than they shrank under osmotic shocks of same magnitude. This distinct trend to gain water, despite the capacity to hold some gradients upon seawater dilution, helps to explain why echinoderms cannot be fully estuarine, or ever enter fresh water.

  13. Application of chiral thiazolidine ligands to asymmetric hydrosilation

    Institute of Scientific and Technical Information of China (English)

    李弘; 姚金水; 何炳林

    1997-01-01

    Seven chiral thiazolidines bound rhodium complexes were synthesized and their catalytic asymmetric hydrosilation properties were investigated It was found through investigation that the configuration of newly formed chiral centre C2 of substituted chiral thiazolidines prepared from L-cysteine or its esters has no effect on the final results of catalytic asymmetric hydrosilation.The direct reason for causing this phenomenon is reported by the present quantitative results for the first time:the rapid racemation of chiral center C2 of chiral thiazolidine ligands takes place under the catalysis of rhodium(Ⅰ) complex [Rh(COD)CI]2

  14. Climate agreements under limited participation, asymmetric information and market imperfections

    Energy Technology Data Exchange (ETDEWEB)

    Hagem, Cathrine

    1996-12-31

    This thesis relates to climate agreements and cost efficiency by analysing the formation of a system of quota leading to distributed discharge of emissions between countries. Main fields concerned are the greenhouse effect, the political process, efficient and cost-effective climate agreements, and climate agreements under limited participation, asymmetric information and market imperfections covering fields like limited participation in climate agreements, limited participation and indirect impact on non-participating countries` emissions, limited participation and direct impact on non-participating countries` emissions under asymmetric information, and non-competitive market for tradeable quotas. 166 refs., 7 tabs.

  15. A novel asymmetric 3D in-vitro assay for the study of tumor cell invasion

    Directory of Open Access Journals (Sweden)

    Neufeld Gera

    2009-11-01

    Full Text Available Abstract Background The induction of tumor cell invasion is an important step in tumor progression. Due to the cost and slowness of in-vivo invasion assays, there is need for quantitative in-vitro invasion assays that mimic as closely as possible the tumor environment and in which conditions can be rigorously controlled. Methods We have established a novel asymmetric 3D in-vitro invasion assay by embedding a monolayer of tumor cells between two layers of collagen. The cells were then allowed to invade the upper and lower layers of collagen. To visualize invading cells the gels were sectioned perpendicular to the monolayer so that after seeding the monolayer appears as a thin line precisely defining the origin of invasion. The number of invading tumor cells, their proliferation rate, the distance they traverse and the direction of invasion could then be determined quantitatively. Results The assay was used to compare the invasive properties of several tumor cell types and the results compare well with those obtained by previously described assays. Lysyl-oxidase like protein-2 (Loxl2 is a potent inducer of invasiveness. Using our assay we show for the first time that inhibition of endogenous Loxl2 expression in several types of tumor cells strongly inhibits their invasiveness. We also took advantage of the asymmetric nature of the assay in order to show that fibronectin enhances the invasiveness of breast cancer cells more potently than laminin. The asymmetric properties of the assay were also used to demonstrate that soluble factors derived from fibroblasts can preferentially attract invading breast cancer cells. Conclusion Our assay displays several advantages over previous invasion assays as it is allows the quantitative analysis of directional invasive behavior of tumor cells in a 3D environment mimicking the tumor microenvironment. It should be particularly useful for the study of the effects of components of the tumor microenvironment on

  16. Effects of direct current on the wetting behavior and interfacial morphology between molten Sn and Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yan; Shen, Ping, E-mail: shenping@jlu.edu.cn; Yang, Nan-Nan; Cao, Kang-Zhan

    2014-02-15

    Highlights: • Applying DC has a noticeable effect on the wetting of oxidized Cu by molten Sn. • Current polarity does not have a strong effect on wettability but on microstructure. • The IMC layer greatly thickens with increasing current intensity. • An unusual morphology was formed at the interface under a larger current intensity. -- Abstract: The effect of applying a direct electric current on the wetting behavior of molten Sn on Cu substrates at a nominal temperature of 510 K was investigated using a sessile drop method. The final stable contact angles were 37 ± 5° without employing a direct current (DC) while they decreased from 29 ± 3° to 16 ± 2° when the current increased from 2.5 A to 7.5 A. The current polarity does not have a noticeable effect on the wetting behavior but on interfacial morphology. Cross-sectional microstructure observations revealed that applying a current promoted the dissolution of the Cu substrate in molten Sn and the effect was enhanced with increasing current intensity. An unusual morphology with Cu{sub 3}Sn being the principal phase and Cu{sub 6}Sn{sub 5} being the secondary phase was observed under a relatively large current intensity, particularly for the case of electrons flowing from the Cu substrate to the molten Sn side. Joule heat-induced Marangoni convection in the liquid droplet and electromigration are likely to play significant roles in determining the wettability and interfacial microstructure under the application of a direct electric current.

  17. Exploring the neural bases of goal-directed motor behavior using fully resolved simulations

    Science.gov (United States)

    Patel, Namu; Patankar, Neelesh A.

    2016-11-01

    Undulatory swimming is an ideal problem for understanding the neural architecture for motor control and movement; a vertebrate's robust morphology and adaptive locomotive gait allows the swimmer to navigate complex environments. Simple mathematical models for neurally activated muscle contractions have been incorporated into a swimmer immersed in fluid. Muscle contractions produce bending moments which determine the swimming kinematics. The neurobiology of goal-directed locomotion is explored using fast, efficient, and fully resolved constraint-based immersed boundary simulations. Hierarchical control systems tune the strength, frequency, and duty cycle for neural activation waves to produce multifarious swimming gaits or synergies. Simulation results are used to investigate why the basal ganglia and other control systems may command a particular neural pattern to accomplish a task. Using simple neural models, the effect of proprioceptive feedback on refining the body motion is demonstrated. Lastly, the ability for a learned swimmer to successfully navigate a complex environment is tested. This work is supported by NSF CBET 1066575 and NSF CMMI 0941674.

  18. Direct and accurate measurement of size dependent wetting behaviors for sessile water droplets

    Science.gov (United States)

    Park, Jimin; Han, Hyung-Seop; Kim, Yu-Chan; Ahn, Jae-Pyeong; Ok, Myoung-Ryul; Lee, Kyung Eun; Lee, Jee-Wook; Cha, Pil-Ryung; Seok, Hyun-Kwang; Jeon, Hojeong

    2015-12-01

    The size-dependent wettability of sessile water droplets is an important matter in wetting science. Although extensive studies have explored this problem, it has been difficult to obtain empirical data for microscale sessile droplets at a wide range of diameters because of the flaws resulting from evaporation and insufficient imaging resolution. Herein, we present the size-dependent quantitative change of wettability by directly visualizing the three phase interfaces of droplets using a cryogenic-focused ion beam milling and SEM-imaging technique. With the fundamental understanding of the formation pathway, evaporation, freezing, and contact angle hysteresis for sessile droplets, microdroplets with diameters spanning more than three orders of magnitude on various metal substrates were examined. Wetting nature can gradually change from hydrophobic at the hundreds-of-microns scale to super-hydrophobic at the sub-μm scale, and a nonlinear relationship between the cosine of the contact angle and contact line curvature in microscale water droplets was demonstrated. We also showed that the wettability could be further tuned in a size-dependent manner by introducing regular heterogeneities to the substrate.

  19. Behaviorism

    National Research Council Canada - National Science Library

    Moore, J

    2011-01-01

    .... Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the observational methods common to all sciences...

  20. Disordered contact process with asymmetric spreading.

    Science.gov (United States)

    Juhász, Róbert

    2013-02-01

    An asymmetric variant of the contact process where the activity spreads with different and independent random rates to the left and to the right is introduced. A real space renormalization scheme is formulated for the model by means of which it is shown that the local asymmetry of spreading is irrelevant on large scales if the model is globally (statistically) symmetric. Otherwise, in the presence of a global bias in either direction, the renormalization method predicts two distinct phase transitions, which are related to the spreading of activity in and against the direction of the bias. The latter is found to be described by an infinite randomness fixed point while the former is not.

  1. The Stochastic Engine Initiative: Improving Prediction of Behavior in Geologic Environments We Cannot Directly Observe

    Energy Technology Data Exchange (ETDEWEB)

    Aines, R; Nitao, J; Newmark, R; Carle, S; Ramirez, A; Harris, D; Johnson, J; Johnson, V; Ermak, D; Sugiyama, G; Hanley, W; Sengupta, S; Daily, W; Glaser, R; Dyer, K; Fogg, G; Zhang, Y; Yu, Z; Levine, R

    2002-05-09

    The stochastic engine uses modern computational capabilities to combine simulations with observations. We integrate the general knowledge represented by models with specific knowledge represented by data, using Bayesian inferencing and a highly efficient staged Metropolis-type search algorithm. From this, we obtain a probability distribution characterizing the likely configurations of the system consistent with existing data. The primary use will be optimizing knowledge about the configuration of a system for which sufficient direct observations cannot be made. Programmatic applications include underground systems ranging from environmental contamination to military bunkers, optimization of complex nonlinear systems, and timely decision-making for complex, hostile environments such as battlefields or the detection of secret facilities. We create a stochastic ''base representation'' of system configurations (states) from which the values of measurable parameters can be calculated using forward simulators. Comparison of these predictions to actual measurements drives embedded Bayesian inferencing, updating the distributions of states in the base representation using the Metropolis method. Unlike inversion methods that generate a single bestcase deterministic solution, this method produces all the likely solutions, weighted by their likelihoods. This flexible method is best applied to highly non-linear, multi-dimensional problems. Staging of the Metropolis searches permits us to run the simplest model systems, such as lithology estimators, at the lower stages. The majority of possible configurations are thus eliminated from further consideration by more complex simulators, such as flow and transport models. Because the method is fully automated, large data sets of a variety of types can be used to refine the system configurations. The most important prerequisites for optimal use of this method are well-characterized forward simulators, realistic

  2. Comprehension and Data-Sharing Behavior of Direct-To-Consumer Genetic Test Customers.

    Science.gov (United States)

    McGrath, Scott P; Coleman, Jason; Najjar, Lotfollah; Fruhling, Ann; Bastola, Dhundy R

    2016-01-01

    The aim of this study was to evaluate current direct-to-consumer (DTC) genetic customers' ability to interpret and comprehend test results and to determine if honest brokers are needed. One hundred and twenty-two customers of the DTC genetic testing company 23andMe were polled in an online survey. The subjects were asked about their personal test results and to interpret the results of two mock test cases (type 2 diabetes and multiple sclerosis), where results were translated into disease probability for an individual compared to the public. When asked to evaluate the risk, 72.1% correctly assessed the first case and 77% were correct on the second case. Only 23.8% of those surveyed were able to interpret both cases correctly. x03C7;2 and logistic regression were used to interpret the results. Participants who took the time to read the DTC test-provided supplemental material were 3.93 times (p = 0.040) more likely to correctly interpret the test results than those who did not. The odds for correctly interpreting the test cases were 3.289 times (p = 0.011) higher for those who made more than USD 50,000 than those who made less. Survey results were compared to the Health Information National Trends Survey (HINTS) phase 4 cycle 3 data to evaluate national trends. Most of the subjects were able to correctly interpret the test cases, yet a majority did not share their results with a health-care professional. As the market for DTC genetic testing grows, test comprehension will become more critical. Involving more health professionals in this process may be necessary to ensure proper interpretations. © 2016 S. Karger AG, Basel.

  3. Switching direction affects switching costs: Behavioral, ERP and time-frequency analyses of intra-sentential codeswitching.

    Science.gov (United States)

    Litcofsky, Kaitlyn A; Van Hell, Janet G

    2017-02-03

    Bilinguals have the unique ability to produce utterances that switch between languages. Most language switching research has focused on isolated, unrelated items, which emphasizes separation of the languages. Fewer studies examined the cognitive and neural mechanisms of switching languages in natural discourse. The present study examined the effect of codeswitching direction on the comprehension of intra-sentential codeswitching in Spanish-English bilinguals, using self-paced reading behavioral measurements (Experiment 1) and electroencephalography (EEG) measurements (Experiment 2), analyzed via both event-related potentials (ERPs) and time-frequency analysis (TFR). Reading times showed a significant switching cost for codeswitched sentences in both codeswitching directions, though switching costs were somewhat higher into the dominant language than into the weaker language. ERPs showed that codeswitched as compared to non-switched words elicited a late positivity, but only when switching from the dominant into the weaker language, not in the reverse direction. TFRs showed complementary and converging results: switches into the weaker language resulted in a power decrease in lower beta band while switches into the dominant language resulted in a power increase in theta band. These multi-method findings provide novel insights into neurocognitive resources engaged in the comprehension of intra-sentential codeswitches related to sentence-level restructuring processes to activate and access the weaker language.

  4. Phase-transfer-catalysed asymmetric synthesis of tetrasubstituted allenes

    Science.gov (United States)

    Hashimoto, Takuya; Sakata, Kazuki; Tamakuni, Fumiko; Dutton, Mark J.; Maruoka, Keiji

    2013-03-01

    Allenes are molecules based on three carbons connected by two cumulated carbon-carbon double bonds. Given their axially chiral nature and unique reactivity, substituted allenes have a variety of applications in organic chemistry as key synthetic intermediates and directly as part of biologically active compounds. Although the demands for these motivated many endeavours to make axially chiral, substituted allenes by exercising asymmetric catalysis, the catalytic asymmetric synthesis of fully substituted ones (tetrasubstituted allenes) remained largely an unsolved issue. The fundamental obstacle to solving this conundrum is the lack of a simple synthetic transformation that provides tetrasubstituted allenes in the action of catalysis. We report herein a strategy to overcome this issue by the use of a phase-transfer-catalysed asymmetric functionalization of 1-alkylallene-1,3-dicarboxylates with N-arylsulfonyl imines and benzylic and allylic bromides.

  5. New Asymmetric Fuzzy PID Control for Pneumatic Position Control System

    Institute of Scientific and Technical Information of China (English)

    薛阳; 彭光正; 范萌; 伍清河

    2004-01-01

    A fuzzy control algorithm of asymmetric fuzzy strategy is introduced for a servo-pneumatic position system. It can effectively solve the difficult problems of single rod low friction cylinders, which are mainly caused by asymmetric structures and different friction characteristics in two directions. On the basis of this algorithm, a traditional PID control is used to improve dynamic performance. Furthermore, a new asymmetric fuzzy PID control with α factor is advanced to improve the self-adaptability and robustness of the system. Both the theoretical analyses and experimental results prove that, with this control strategy, the dynamic performance of the system can be greatly improved. The system using this control algorithm has strong robustness and it obtains desired overshoot and repeatability in both transient and steady-state responses.

  6. [Behavior of the hypothalamo-hypophyseal axis in a patient with asymmetric mixed gonadal dysgenesis (chromosome pattern 45,XO/46,XY) before and after gonad excision after with arginine, GRH and TRH stimulation].

    Science.gov (United States)

    Rudolf, K; Kunkel, S; Büttner, H H; Pelz, L; Meissner, J

    1982-07-01

    In a 12 years old patient with asymmetric mixed gonadal dysgenesis (karyotype 45, XO/46,XY) a stimulation test with arginine, gonadotropin-releasing hormone (GRH) and thyreotropin-releasing hormone (TRH) was performed before and after exstirpation of the gonads as well as after application of sex steroids. FSH, LH, PRL, HGH, TSH, testosterone and oestradiol were determined by radioimmunoassay. The results show an intact hypothalamo-pituitary axis which reacts with a normal negative feedback with respect to the secretion of gonadotropins after application of sex steroids.

  7. Synthesis of Asymmetric Propanetriol Analogues

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as chiral synthons of lysophosphatidic acid and other compounds with asymmetric propanetriol backbone.

  8. Catalytic Asymmetric Bromocyclization of Polyenes.

    Science.gov (United States)

    Samanta, Ramesh C; Yamamoto, Hisashi

    2017-02-01

    The first catalytic asymmetric bromonium ion-induced polyene cyclization has been achieved by using a chiral BINOL-derived thiophosphoramide catalyst and 1,3-dibromo-5,5-dimethylhydantoin as an electrophilic bromine source. Bromocyclization products are obtained in high yields, with good enantiomeric ratios and high diastereoselectivity, and are abundantly found as scaffolds in natural products.

  9. Aspects of Collisionless Magnetic Reconnection in Asymmetric Systems

    Science.gov (United States)

    Hesse, Michael; Aunai, Nicolas; Zeitani, Seiji; Kuznetsova, Masha; Birn, Joachim

    2013-01-01

    Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with non-vanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.

  10. Selfhealing of asymmetric Bessel-like modes

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten

    2014-01-01

    We numerically investigate asymmetric Bessel-like modes in an aircladding fiber. The selfhealing ability of asymmetric Bessel-like modes is demonstrated and quantified including the angular dependency of this ability.......We numerically investigate asymmetric Bessel-like modes in an aircladding fiber. The selfhealing ability of asymmetric Bessel-like modes is demonstrated and quantified including the angular dependency of this ability....

  11. Phase diagram of highly asymmetric binary hard-sphere mixtures.

    Science.gov (United States)

    Dijkstra, M; van Roij, R; Evans, R

    1999-05-01

    We study the phase behavior and structure of highly asymmetric binary hard-sphere mixtures. By first integrating out the degrees of freedom of the small spheres in the partition function we derive a formal expression for the effective Hamiltonian of the large spheres. Then using an explicit pairwise (depletion) potential approximation to this effective Hamiltonian in computer simulations, we determine fluid-solid coexistence for size ratios q=0.033, 0.05, 0.1, 0.2, and 1.0. The resulting two-phase region becomes very broad in packing fractions of the large spheres as q becomes very small. We find a stable, isostructural solid-solid transition for q0 the phase diagram mimics that of the sticky-sphere system. As expected, the radial distribution function g(r) and the structure factor S(k) of the effective one-component system show no sharp signature of the onset of the freezing transition and we find that at most points on the fluid-solid boundary the value of S(k) at its first peak is much lower than the value given by the Hansen-Verlet freezing criterion. Direct simulations of the true binary mixture of hard spheres were performed for q > or =0.05 in order to test the predictions from the effective Hamiltonian. For those packing fractions of the small spheres where direct simulations are possible, we find remarkably good agreement between the phase boundaries calculated from the two approaches-even up to the symmetric limit q=1 and for very high packings of the large spheres, where the solid-solid transition occurs. In both limits one might expect that an approximation which neglects higher-body terms should fail, but our results support the notion that the main features of the phase equilibria of asymmetric binary hard-sphere mixtures are accounted for by the effective pairwise depletion potential description. We also compare our results with those of other theoretical treatments and experiments on colloidal hard-sphere mixtures.

  12. Asymmetric multifractal detrending moving average analysis in time series of PM2.5 concentration

    Science.gov (United States)

    Zhang, Chen; Ni, Zhiwei; Ni, Liping; Li, Jingming; Zhou, Longfei

    2016-09-01

    In this paper, we propose the asymmetric multifractal detrending moving average analysis (A-MFDMA) method to explore the asymmetric correlation in non-stationary time series. The proposed method is applied to explore the asymmetric correlation of PM2.5 daily average concentration with uptrends or downtrends in China. In addition, shuffling and phase randomization procedures are applied to detect the sources of multifractality. The results show that existences of asymmetric correlations, and the asymmetric correlations are multifractal. Further, the multifractal scaling behavior in the Chinese PM2.5 is caused not only by long-range correlation but also by fat-tailed distribution, but the major source of multifractality is fat-tailed distribution.

  13. Direct observation of anodic dissolution and filament growth behavior in polyethylene-oxide-based atomic switch structures

    Science.gov (United States)

    Krishnan, Karthik; Tsuruoka, Tohru; Aono, Masakazu

    2016-06-01

    We directly observed anodic dissolution and subsequent filament growth behavior in a planar atomic switch structure with Ag salt incorporated polyethylene oxide (Ag-PEO) film using in situ optical microscopy and ex situ scanning electron microscopy. The high ionic conductivities of Ag-PEO films enable the investigation of filament formation under voltage bias, even in micrometer-scaled devices. It was found that the filament formation changes from unidirectional growth to dendritic growth, depending on its distance from the grounded electrode. Based on this understanding of filament growth dynamics in planar devices, highly stable resistive switching was achieved in an Ag/Ag-PEO/Pt stacked device with an Ag-PEO film thickness of 100 nm. The device showed repeated switching operations for more than 102 sweep cycles, with a high ON/OFF resistance ratio of 105.

  14. Self-organization of laterally asymmetrical movements as a consequence of space-time optimization.

    Science.gov (United States)

    Mangalam, Madhur; Desai, Nisarg; Singh, Mewa

    2016-02-07

    Laterally asymmetrical movements are ubiquitous among organisms. A bilaterally symmetrical organism cannot maneuver through a two- or three-dimensional space unless and until one side of its body leads, because the forces that cause the movements of the body are generated within the body. One question follows: are there any costs or benefits of laterally asymmetrical movements? We test whether directionally consistent laterally asymmetrical movements at different levels of organization of movements (at the individual, and not the population level) can work synergistically. We show-by means of a hypothetical system resembling a humanoid robot-that a laterally asymmetrical movement at a lower level of organization of movements can stimulate laterally asymmetrical movements that are directionally consistent at consecutive higher levels. We show-by comparing two hypothetical systems, incorporating laterally symmetrical and asymmetrical movements, respectively-that the asymmetrical system outperforms the symmetrical system by optimizing space and time and that this space-time advantage increases with the increasing complexity of the task. Together, these results suggest that laterally asymmetrical movements can self-organize as a consequence of space-time optimization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Rare male aggression directed toward females in a female-dominated society: Baiting behavior in the spotted hyena

    Science.gov (United States)

    Szykman, Micaela; Engh, Anne L.; Van Horn, Russell C.; Boydston, Erin E.; Scribner, Kim T.; Holekamp, Kay E.

    2003-01-01

    Spotted hyenas (Crocuta crocuta) are gregarious carnivores. The females are socially dominant to males, and adult males rarely direct aggression toward adult females. This study analyzed all cases in which adult immigrant males behaved aggressively toward adult females in a large population of free-living hyenas in Kenya, observed for 11 years. Our goals were to describe the conditions under which male attacks on females occur, and address possible adaptive functions. Most aggression directed by adult immigrant males against females occurred when coalitions of two or more males attacked a single adult female, who typically responded by defending herself and fighting back. Male aggression against females frequently occurred at sites of ungulate kills, but males never behaved aggressively toward females over food, and all male attacks on females were unprovoked. Although no mounting or other copulatory behaviors ever occurred during or immediately after an attack, the number of male attacks on females peaked around the time of conception. Daily rates at which males attacked females did not vary with female social rank. However, daily attack rates did vary significantly with female reproductive state, and the highest rates of male attack on females were observed during the two stages of the reproductive cycle during which females were most likely to conceive litters. The adaptive significance of male aggression against females in this species remains unknown, but a tight association between male attacks on females and a female's time of conception provides strong evidence of some role for male aggression in hyena sexual behavior. In particular, our data are consistent with hypotheses suggesting that male aggression toward females in this species either serves to inform females about male fitness or represents sexual harassment.

  16. Direct measurements of IPTG enable analysis of the induction behavior of E. coli in high cell density cultures

    Directory of Open Access Journals (Sweden)

    Fernández-Castané Alfred

    2012-05-01

    Full Text Available Abstract Background The E. coli lac operon and its components have been studied for decades, and lac-derived systems are widely used for recombinant protein production. However, lac operon dynamics and induction behavior remain the paradigm of gene regulation. Recently, an HPLC-MS-based method to quantify IPTG in the medium and inside the biomass has been established, and this tool may be useful to uncover the lack of knowledge and allow optimization of biotechnological processes. Results The results obtained from the study of IPTG distribution profiles in fed-batch, high cell density cultures allowed discrimination between two different depletion patterns of an inducer from the medium to the biomass in E. coli-expressing rhamnulose-1-phosphate aldolase (RhuA. Moreover, we could demonstrate that active transport mediates the uptake of this gratuitous inducer. Additionally, we could study the induction behaviors of this expression system by taking into account the biomass concentration at the induction time. Conclusions In the bistable range, partial induction occurred, which led to intermediate levels of RhuA activity. There was a direct relationship between the initial inducer concentrations and the initial inducer transport rate together with the specific activity. A majority of the inducer remains in the medium to reach equilibrium with the intracellular level. The intracellular inducer accumulation was a further evidence of bistability of the lac operon.

  17. Predicting Use of Ineffective Responsive, Structure and Control Vegetable Parenting Practices with the Model of Goal Directed Behavior.

    Science.gov (United States)

    Baranowski, Tom; Beltran, Alicia; Chen, Tzu-An; Thompson, Debbe; O'Connor, Teresia; Hughes, Sheryl; Diep, Cassandra; Baranowski, Janice C

    This study reports the modeling of three categories of ineffective vegetable parenting practices (IVPP) separately (responsive, structure, and control vegetable parenting practices). An internet survey was employed for a cross sectional assessment of parenting practices and cognitive-emotional variables. Parents (n=307) of preschool children (3-5 years old) were recruited through announcements and postings. Models were analyzed with block regression and backward deletion procedures using a composite IVPP scale as the dependent variable. The independent variables included validated scales from a Model of Goal Directed Vegetable Parenting Practices (MGDVPP), including: intention, habit, perceived barriers, desire, competence, autonomy, relatedness, attitudes, norms, perceived behavioral control, and anticipated emotions. The available scales accounted for 26.5%, 16.7% and 44.6% of the variance in the IVPP responsive, structure and control subscales, respectively. Different sets of diverse variables predicted the three IVPP constructs. Intentions, Habits and Perceived Behavioral Control were strong predictors for each of the IVPP constructs, but the subscales were specific to each IVPP construct. Parent emotional responses, an infrequently investigated variable, was an important predictor of ineffective responsive vegetable parenting practices and ineffective structure vegetable parenting practices, but not ineffective control vegetable parenting practices. An Attitude subscale and a Norms subscale predicted ineffective responsive vegetable parenting practices alone. This was the first report of psychometrically tested scales to predict use of IVPP subscales. Further research is needed to verify these findings in larger longitudinal cohorts. Interventions to increase child vegetable intake may have to reduce IVPP.

  18. Analytical approach to calculate bending, longitudinal and torsional local stiffness of an asymmetric circumferential crack with contact condition

    Science.gov (United States)

    Sharafi, Mojtaba Meidan; Nikravesh, Majid Yadavar; Safarpour, Pedram

    2017-09-01

    In this paper, bending, longitudinal and torsional stiffness of an eccentric circumferential crack is investigated with taking into account contact condition on the crack surfaces based on fracture mechanics. Although several researches have analyzed stress intensity factors of symmetric circumferential crack, the stiffness of an asymmetric circumferential crack in different directions (along and perpendicular to eccentricity) regarding contact condition has not been studied by an analytical method until now. In this paper we aim to describe behavior of eccentric circumferential crack under axial loading and establish a relation between axial force and the resulting displacement vector. The twisting angle of asymmetric circumferential crack due to torsional loading is also calculated and compared to twisting angle of a symmetric crack. In order to simulate the local bending stiffness in the contact condition, nonlinear governing equations of bending stiffness associated to cracked beam section is developed by dividing it to strip elements and utilizing stiffness equations related to noncontact condition. It is validated by 3D finite element (FE) nonlinear model. Results show a significant compatibility between presented analytical and 3D FE methods. Moreover results of simulations show that without taking into account contact condition, axial, torsional and bending stiffness of symmetric and asymmetric circumferential crack are equal and radius of un-cracked area is the only influential factor.

  19. Non-suicidal self-injury and other self-directed violent behaviors in India: A review of definitions and research.

    Science.gov (United States)

    Gandhi, Amarendra; Luyckx, Koen; Maitra, Shubhada; Claes, Laurence

    2016-08-01

    The interpersonal theory of suicide suggests that most forms of self-directed violent behaviors lie on a continuum, with each behavior successively increasing the capability of committing suicide. There is increasing evidence to suggest that the continuum may begin with Non-Suicidal Self-Injury (NSSI). This theory can be important in developing interventions for suicide prevention. However, in India, consistent usage of definitions of various forms of self-directed violent behaviors is lacking. In the present study, we reviewed definitions of various forms of self-directed violent behaviors that have been investigated in India. Further, we compared the usage of these definitions with the usage by WHO. Additionally, we reviewed NSSI research in India. Thirty-eight publications were identified by a comprehensive electronic search undertaken in Indian psychiatry, psychology, and mental health-related databases. Inconsistent definitions of eight self-directed violent behaviors were observed in Indian literature. Agreement on consistent definitions of various forms of self-directed behaviors is essential. Based on the findings of the current review, it can be suggested that culturally relevant large-scale research on NSSI in India is required to confirm the limited evidence that suggests high prevalence of NSSI in India.

  20. Asymmetric Hybrid Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chumanov, George [Clemson Univ., SC (United States)

    2015-11-05

    Hybrid Nanoparticles (AHNs) are rationally-designed multifunctional nanostructures and novel building blocks for the next generation of advanced materials and devices. Nanoscale materials attract considerable interest because of their unusual properties and potential for practical applications. Most of the activity in this field is focused on the synthesis of homogeneous nanoparticles from metals, metal oxides, semiconductors, and polymers. It is well recognized that properties of nanoparticles can be further enhanced if they are made as hybrid structures. This program is concerned with the synthesis, characterization, and application of such hybrid structures termed AHNs. AHNs are composed of a homogeneous core and several caps of different materials deposited on its surface (Fig. 1). Combined properties of the core and the caps as well as new properties that arise from core-cap and cap-cap interactions render AHNs multifunctional. In addition, specific chemical reactivity of the caps enables directional self-assembly of AHNs into complex architectures that are not possible with only spherical nanoparticles.

  1. Asymmetric Multilevel Diversity Coding and Asymmetric Gaussian Multiple Descriptions

    CERN Document Server

    Mohajer, Soheil; Diggavi, Suhas N

    2009-01-01

    We consider the asymmetric multilevel diversity (A-MLD) coding problem, where a set of $2^K-1$ information sources, ordered in a decreasing level of importance, is encoded into $K$ messages (or descriptions). There are $2^K-1$ decoders, each of which has access to a non-empty subset of the encoded messages. Each decoder is required to reproduce the information sources up to a certain importance level depending on the combination of descriptions available to it. We obtain a single letter characterization of the achievable rate region for the 3-description problem. In contrast to symmetric multilevel diversity coding, source-separation coding is not sufficient in the asymmetric case, and ideas akin to network coding need to be used strategically. Based on the intuitions gained in treating the A-MLD problem, we derive inner and outer bounds for the rate region of the asymmetric Gaussian multiple description (MD) problem with three descriptions. Both the inner and outer bounds have a similar geometric structure t...

  2. Transcranial direct current stimulation reduces food-craving and measures of hyperphagia behavior in participants with Prader-Willi syndrome.

    Science.gov (United States)

    Bravo, Gabriela L; Poje, Albert B; Perissinotti, Iago; Marcondes, Bianca F; Villamar, Mauricio F; Manzardo, Ann M; Luque, Laura; LePage, Jean F; Stafford, Diane; Fregni, Felipe; Butler, Merlin G

    2016-03-01

    Prader-Willi syndrome (PWS) is a neurodevelopmental genetic disorder characterized by intellectual disabilities and insatiable appetite with compulsive eating leading to severe obesity with detrimental health consequences. Transcranial direct current stimulation (tDCS) has been shown to modulate decision-making and cue-induced food craving in healthy adults. We conducted a pilot double blind, sham-controlled, multicenter study of tDCS modulation of food drive and craving in 10 adult PWS participants, 11 adult obese (OB) and 11 adult healthy-weight control (HWC) subjects. PWS and OB subjects received five consecutive daily sessions of active or sham tDCS over the right dorsolateral prefrontal cortex (DLPFC), while HWC received a single sham and active tDCS in a crossover design. Standardized psychometric instruments assessed food craving, drive and hyperphagia by self-report and caregiver assessment over 30 days. Robust baseline differences were observed in severity scores for the Three-Factor Eating Questionnaire (TFEQ) and Dykens Hyperphagia Questionnaire (DHQ) for PWS compared to HWC while obese participants were more similar to HWC. Active tDCS stimulation in PWS was associated with a significant change from baseline in TFEQ Disinhibition (Factor II) (Ƶ = 1.9, P food drive and behaviors impacting hyperphagia in PWS. Transcranial direct current stimulation may represent a straight-forward, low risk and low cost method to improve care, management and quality of life in PWS.

  3. Deaging and Asymmetric Energy Landscapes in Electrically Biased Ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Tutuncu, Goknur; Damjanovic, Dragan; Chen, Jun; Jones, Jacob L. (Ecole); (UST - China); (Florida)

    2015-09-01

    In ferroic materials, the dielectric, piezoelectric, magnetic, and elastic coefficients are significantly affected by the motion of domain walls. This motion can be described as the propagation of a wall across various types and strengths of pinning centers that collectively constitute a force profile or energetic landscape. Biased domain structures and asymmetric energy landscapes can be created through application of high fields (such as during electrical poling), and the material behavior in such states is often highly asymmetric. In some cases, this behavior can be considered as the electric analogue to the Bauschinger effect. The present Letter uses time-resolved, high-energy x-ray Bragg scattering to probe this asymmetry and the associated deaging effect in the ferroelectric morphotropic phase boundary composition 0.36BiScO{sub 3}-0.64PbTiO{sub 3}.

  4. Budding Transition of Asymmetric Two-component Lipid Domains

    CERN Document Server

    Wolff, Jean; Andelman, David

    2016-01-01

    We propose a model that accounts for the budding transition of asymmetric two-component lipid domains, where the two monolayers (leaflets) have different average compositions controlled by independent chemical potentials. Assuming a coupling between the local curvature and local lipid composition in each of the leaflets, we discuss the morphology and thermodynamic behavior of asymmetric lipid domains. The membrane free-energy contains three contributions: the bending energy, the line tension, and a Landau free-energy for a lateral phase separation. Within a mean-field treatment, we obtain various phase diagrams containing fully budded, dimpled, and flat states as a function of the two leaflet compositions. The global phase behavior is analyzed, and depending on system parameters, the phase diagrams include one-phase, two-phase and three-phase regions. In particular, we predict various phase coexistence regions between different morphologies of domains, which may be observed in multi-component membranes or ves...

  5. Cosmology in time asymmetric extensions of general relativity

    CERN Document Server

    Leon, Genly

    2015-01-01

    We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a way that the algebra of constraints and local physics remain unchanged. Nevertheless, at cosmological scales these new terms can have significant effects that can alter the universe evolution, both at early and late times, and the freedom in the choice of the involved modification function makes the scenario able to produce a huge class of cosmological behaviors. For basic ansatzes of modification, we perform a detailed dynamical analysis, extracting the stable late time solutions. Amongst others, we find that the universe can result in dark-energy dominated, accelerating solutions, even in the absence of an explicit cosmological constant, in which the dark energy can be quintessence-like, phantom-like, or behave as an effective cosmological constant. Moreover, it can result...

  6. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size-asymmetric ......A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size...

  7. Mab-3 is a direct tra-1 target gene regulating diverse aspects of C. elegans male sexual development and behavior.

    Science.gov (United States)

    Yi, W; Ross, J M; Zarkower, D

    2000-10-01

    Sex determination is controlled by global regulatory genes, such as tra-1 in Caenorhabditis elegans, Sex lethal in Drosophila, or Sry in mammals. How these genes coordinate sexual differentiation throughout the body is a key unanswered question. tra-1 encodes a zinc finger transcription factor, TRA-1A, that regulates, directly or indirectly, all genes required for sexual development. mab-3 (male abnormal 3), acts downstream of tra-1 and is known to be required for sexual differentiation of at least two tissues. mab-3 directly regulates yolk protein transcription in the intestine and specifies male sense organ differentiation in the nervous system. It encodes a transcription factor related to the products of the Drosophila sexual regulator doublesex (dsx), which also regulates yolk protein transcription and male sense-organ differentiation. The similarities between mab-3 and dsx led us to suggest that some aspects of sex determination may be evolutionarily conserved. Here we find that mab-3 is also required for expression of male-specific genes in sensory neurons of the head and tail and for male interaction with hermaphrodites. These roles in male development and behavior suggest further functional similarity to dsx. In male sensory ray differentiation we find that MAB-3 acts synergistically with LIN-32, a neurogenic bHLH transcription factor. Expression of LIN-32 is spatially restricted by the combined action of the Hox gene mab-5 and the hairy homolog lin-22, while MAB-3 is expressed throughout the lateral hypodermis. Finally, we find that mab-3 transcription is directly regulated in the intestine by TRA-1A, providing a molecular link between the global regulatory pathway and terminal sexual differentiation.

  8. Behaviorism

    Science.gov (United States)

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  9. Behaviorism

    Science.gov (United States)

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  10. Thermal rectification in three-dimensional asymmetric nanostructure.

    Science.gov (United States)

    Lee, Jonghoon; Varshney, Vikas; Roy, Ajit K; Ferguson, John B; Farmer, Barry L

    2012-07-11

    Previously, thermal rectification has been reported in several low-dimensional shape-asymmetric nanomaterials. In this Letter, we demonstrate that a three-dimensional crystalline material with an asymmetric shape also displays as strong thermal rectification as low-dimensional materials do. The observed rectification is attributed to the stronger temperature dependence of vibration density of states in the narrower region of the asymmetric material, resulting from the small number of atomic degrees of freedom directly interacting with the thermostat. We also demonstrate that the often reported "device shape asymmetry" is not a sufficient condition for thermal rectification. Specifically, the size asymmetry in boundary thermal contacts is equally important toward determining the magnitude of thermal rectification. When the boundary thermal contacts retain the same size asymmetry as the nanomaterial, the overall system displays notable thermal rectification, in accordance with existing literature. However, when the wider region of the asymmetric nanomaterial is partially thermostatted by a smaller sized contact, thermal rectification decreases dramatically and even changes direction.

  11. Superpositions of asymmetrical Bessel beams.

    Science.gov (United States)

    Kotlyar, V V; Kovalev, A A; Soifer, V A

    2015-06-01

    We considered nonparaxial asymmetrical Bessel modes of the first and second types, which differ from a conventional symmetrical Bessel mode by a real-valued shift along one Cartesian coordinate and an imaginary shift along another (both shifts are equal in modulus). The first- and second-type Bessel modes differ only in signs of the shift and, therefore, have different orbital angular momentum (OAM) (integer or fractional). Addition and subtraction of complex amplitudes of two identical asymmetrical Bessel modes of the first and second type lead to light beams with the same integer OAM equal to the topological charge n of the original mode, but with different transverse intensity distributions, which depend on the shift magnitude. This proposed method allows controlling of the OAM of the beam with simultaneous changing of its shape, i.e., for matching with the object being trapped.

  12. Asymmetric cell division of stem cells in the lung and other systems.

    Science.gov (United States)

    Berika, Mohamed; Elgayyar, Marwa E; El-Hashash, Ahmed H K

    2014-01-01

    New insights have been added to identification, behavior and cellular properties of embryonic and tissue-specific stem cells over the last few years. The modes of stem cell division, asymmetric vs. symmetric, are tightly regulated during development and regeneration. The proper choice of a stem cell to divide asymmetrically or symmetrically has great consequences for development and disease because inappropriate asymmetric division disrupts organ morphogenesis, whereas uncontrolled symmetric division induces tumorigenesis. Therefore, understanding the behavior of lung stem cells could identify innovative solutions for restoring normal morphogenesis and/or regeneration of different organs. In this concise review, we describe recent studies in our laboratory about the mode of division of lung epithelial stem cells. We also compare asymmetric cell division (ACD) in the lung stem cells with other tissues in different organisms.

  13. Asymmetric information and macroeconomic dynamics

    Science.gov (United States)

    Hawkins, Raymond J.; Aoki, Masanao; Roy Frieden, B.

    2010-09-01

    We show how macroeconomic dynamics can be derived from asymmetric information. As an illustration of the utility of this approach we derive the equilibrium density, non-equilibrium densities and the equation of motion for the response to a demand shock for productivity in a simple economy. Novel consequences of this approach include a natural incorporation of time dependence into macroeconomics and a common information-theoretic basis for economics and other fields seeking to link micro-dynamics and macro-observables.

  14. Asymmetrical Γ-Source Inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Poh Chiang, Loh; Blaabjerg, Frede

    2014-01-01

    , inverters with coupled transformers have been introduced, but they usually lead to high turns ratio, and hence many winding turns, at high gain. An alternative would then be the asymmetrical Γ-source inverters proposed in this paper, whose gain is raised by lowering their turns ratio toward unity. The input...... current drawn by the proposed inverters is smoother and, hence, more adaptable by the source. Theories and experimental results have been presented in this paper for validating the concepts proposed....

  15. Microstructure and texture of asymmetrically rolled aluminium and titanium after deformation and recrystallization

    Science.gov (United States)

    Wronski, M.; Wierzbanowski, K.; Wronski, S.; Bacroix, B.

    2015-08-01

    Asymmetric rolling is used to modify material properties and to reduce forces and torques applied during deformation. This geometry of deformation is relatively easy to implement on existing industrial rolling mills and it can provide large volumes of a material. The results of the study of microstructure and crystallographic texture in asymmetrically rolled aluminium 6061 and titanium (grade 2) are presented in this work. These characteristics were determined using the EBSD technique and X-ray diffraction. The rolling asymmetry was realized using two identical rolls, driven by independent motors, rotating with different angular velocities. It was found that asymmetric rolling leads to microstructural refinement and texture rotation (around the transverse direction). The impact of asymmetric rolling on microstructural refinement appears also in recrystallized samples of both materials. On the other hand, texture rotation, caused by asymmetric rolling, persists after annealing in titanium but not in aluminium samples.

  16. Seismic Responses of Asymmetric Base-Isolated Structures under Near-Fault Ground Motion

    Institute of Scientific and Technical Information of China (English)

    YE Kun; LI Li; FANG Qin-han

    2008-01-01

    An inter-story shear model of asymmetric base-isolated structures incorporating deformation of each isolation bearing was built, and a method to simultaneously simulate bi-directional near-fault and far-field ground motions was proposed. A comparative study on the dynamic responses of asymmetric base-isolated structures under near-fault and far-field ground motions were conducted to investigate the effects of eccentricity in the isolation system and in the superstructures, the ratio of the uncoupled torsional to lateral frequency of the superstructure and the pulse period of near-fault ground motions on the nonlinear seismic response of asymmetric base-isolated structures. Numerical results show that eccentricity in the isolation system makes asymmetric base-isolated structure more sensitive to near-fault ground motions, and the pulse period of near-fault ground motions plays an import role in governing the seismic responses of asymmetric base-isolated structures.

  17. The Respiratory Impedance in an Asymmetric Model of the Lung Structure

    Directory of Open Access Journals (Sweden)

    Robin De Keyser

    2011-01-01

    Full Text Available This paper presents a model of the respiratory tree as a recurrent, but asymmetric, structure. The intrinsic properties posed by such a system lead to a multi-fractal structure, i.e. a non-integer order model of the total impedance. The fractional order behavior of the asymmetric tree simulated as a dynamic system is assessed by means of Bode plots, on a wide range of frequencies. The results indicate than in a specific frequency range, both the symmetric
    and asymmetric representation of the respiratory tree lead to similar values in the impedance.

  18. The effects of stretching exercise for upper trapezius on the asymmetric rate of bite force.

    Science.gov (United States)

    Lee, Bomjin; Lee, Joongsook; Yang, Jeongok; Heo, Kwangjin; Hwang, Hojin; Kim, Boyoung; Han, Dongwook

    2015-07-01

    [Purpose] The purpose of this study was to observe the effects of stretching the upper trapezius muscle on the asymmetric rate of bite force. [Subjects] Forty-seven female university students who had all their original teeth, had no disorders in the temporomandibular joints, and had never worn braces; participated in this study. [Methods] An occlusometer was used to measure biting forces. Subsequently, stretching exercises of the upper trapezius were performed. The subjects were divided into 3 groups at the start of the testing: the asymmetric rate of the first group was less than 10%; the asymmetric rate of the second group was between 10% and 20%; and the asymmetric rate of the third group was more than 20%. The stretching exercises were done on the dominant side of the upper trapezius. [Results] After the stretching exercises of the upper trapezius, the results showed that for the first group, whose asymmetric rate of biting force was less than 10%, there was a significant increase in asymmetric rate (from 5.1% to 10.3%). For the second group, whose asymmetric rate of biting force was measured to be between 10% and 20%, the asymmetric rate decreased from 14.7% to 14.3%, but the change was not statistically significant. For the third group, whose asymmetric rate of biting force was more than 20%, there was a significant decrease in asymmetric rate (from 27.8% to 12.6%). [Conclusion] We concluded that stretching exercises of the upper trapezius muscle had a direct effect on the asymmetric rate of biting force.

  19. Up-down asymmetric tokamaks

    CERN Document Server

    Ball, Justin

    2016-01-01

    Bulk toroidal rotation has proven capable of stabilising both dangerous MHD modes and turbulence. In this thesis, we explore a method to drive rotation in large tokamaks: up-down asymmetry in the magnetic equilibrium. We seek to maximise this rotation by finding optimal up-down asymmetric flux surface shapes. First, we use the ideal MHD model to show that low order external shaping (e.g. elongation) is best for creating up-down asymmetric flux surfaces throughout the device. Then, we calculate realistic up-down asymmetric equilibria for input into nonlinear gyrokinetic turbulence analysis. Analytic gyrokinetics shows that, in the limit of fast shaping effects, a poloidal tilt of the flux surface shaping has little effect on turbulent transport. Since up-down symmetric surfaces do not transport momentum, this invariance to tilt implies that devices with mirror symmetry about any line in the poloidal plane will drive minimal rotation. Accordingly, further analytic investigation suggests that non-mirror symmetri...

  20. Magnetoresistive system with concentric ferromagnetic asymmetric nanorings

    Energy Technology Data Exchange (ETDEWEB)

    Avila, J. I., E-mail: javila@ulg.ac.be; Tumelero, M. A.; Pasa, A. A.; Viegas, A. D. C. [Laboratório de Filmes Finos e Superfícies (LFFS), Departamento de Física, Universidade Federal de Santa Catarina, CP 476 Florianópolis (Brazil)

    2015-03-14

    A structure consisting of two concentric asymmetric nanorings, each displaying vortex remanent states, is studied with micromagnetic calculations. By orienting in suitable directions, both the asymmetry of the rings and a uniform magnetic field, the vortices chiralities can be switched from parallel to antiparallel, obtaining in this way the analogue of the ferromagnetic and antiferromagnetic configurations found in bar magnets pairs. Conditions on the thickness of single rings to obtain vortex states, as well as formulas for their remanent magnetization are given. The concentric ring structure enables the creation of magnetoresistive systems comprising the qualities of magnetic nanorings, such as low stray fields and high stability. A possible application is as contacts in spin injection in semiconductors, and estimations obtained here of magnetoresistance change for a cylindrical spin injection based device show significant variations comparable to linear geometries.

  1. Activation of carboxylic acids in asymmetric organocatalysis.

    Science.gov (United States)

    Monaco, Mattia Riccardo; Poladura, Belén; Diaz de Los Bernardos, Miriam; Leutzsch, Markus; Goddard, Richard; List, Benjamin

    2014-07-01

    Organocatalysis, catalysis using small organic molecules, has recently evolved into a general approach for asymmetric synthesis, complementing both metal catalysis and biocatalysis. Its success relies to a large extent upon the introduction of novel and generic activation modes. Remarkably though, while carboxylic acids have been used as catalyst directing groups in supramolecular transition-metal catalysis, a general and well-defined activation mode for this useful and abundant substance class is still lacking. Herein we propose the heterodimeric association of carboxylic acids with chiral phosphoric acid catalysts as a new activation principle for organocatalysis. This self-assembly increases both the acidity of the phosphoric acid catalyst and the reactivity of the carboxylic acid. To illustrate this principle, we apply our concept in a general and highly enantioselective catalytic aziridine-opening reaction with carboxylic acids as nucleophiles.

  2. Spectral measurements of asymmetrically irradiated capsule backlighters

    Science.gov (United States)

    Keiter, P. A.; Drake, R. P.

    2016-11-01

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies [J. F. Hansen et al., Rev. Sci. Instrum. 79, 013504 (2008)]. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of 2-13 keV and time-resolved spectra over the photon energy range of 2-3 keV. We will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  3. Chilly Dark Sectors and Asymmetric Reheating

    CERN Document Server

    Adshead, Peter; Shelton, Jessie

    2016-01-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, $N_{\\mathrm{eff}}$, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and ...

  4. Asymmetric Electron Transport at Monolayer-Bilayer Heterojunctions of Epitaxial Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Li, An-Ping [ORNL; Clark, Kendal W [ORNL; Zhang, Xiaoguang [ORNL; Gu, Gong [University of Tennessee, Knoxville (UTK); He, Guowei [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)

    2014-01-01

    The symmetry of the graphene honeycomb lattice is a key element determining many of graphene s unique electronic properties, such as the linear energy-momentum dispersion and the suppressed backscattering 1,2. However, line defects in large-scale epitaxial graphene films, such as grain boundaries, edges, surface steps, and changes in layer thickness, often break the sublatttice symmetry and can impact transport properties of graphene profoundly 3-6. Here we report asymmetric electron transport upon polarity reversal at individual monolayer-bilayer (ML-BL) boundaries in epitaxial graphene on SiC (0001), revealed by scanning tunneling potentiometry. A greater voltage drop is observed when the current flows from BL to ML graphene than in the reverse direction, and the difference remains nearly unchanged with increasing current. This is not a typical nonlinear conductance due to electron transmission through an asymmetric potential. Rather, it indicates the opening of a dynamic energy gap at the Fermi energy due to the Coulomb interaction between the injected nonequilibrium electron density and the pseudospin polarized Friedel oscillation charge density at the boundary. This intriguing heterojunction transport behavior opens a new avenue towards novel quantum functions such as quantum switching.

  5. Dissociable contributions of the left and right posterior medial orbitofrontal cortex in motivational control of goal-directed behavior.

    Science.gov (United States)

    Szatkowska, Iwona; Szymańska, Olga; Marchewka, Artur; Soluch, Paweł; Rymarczyk, Krystyna

    2011-09-01

    Several findings from both human neuroimaging and nonhuman primate studies suggest that the posterior medial orbitofrontal cortex (OFC) may be critical for the motivational control of goal-directed behavior. The present study was conducted to clarify the role of the left and right posterior medial OFC in that function by examining the effects of focal unilateral lesions to this region on the performance on an incentive working memory task. The study covered patients who had undergone surgery for an ACoA aneurysm and normal control subjects (C). The patients were subdivided into three groups: those with resection of the left (LGR+) or right (RGR+) posterior part of the gyrus rectus, and without such a resection (GR-). Participants performed a 2-back working memory task under three motivational conditions (penalty, reward, and no-incentive). The C group performed worse in the penalty condition and better in the reward condition as compared to the no-incentive condition. Similar results were obtained for the GR- group. Performance of the LGR+ group did not depend on incentive manipulations, whereas the RGR+ group performed better in both the penalty and reward conditions than in the no-incentive condition. The results show that the posterior medial OFC is involved in the motivational modulation of working memory performance. Our findings also suggest that the left posterior medial OFC plays a crucial role in this function, whereas the right posterior medial OFC is particularly involved in the processing of the punishing aspect of salient events and it probably mediates in guiding behavior on the basis of negative outcomes of action.

  6. Electrophysiological and Behavioral Effects of Combined Transcranial Direct Current Stimulation and Alcohol Approach Bias Retraining in Hazardous Drinkers.

    Science.gov (United States)

    den Uyl, Tess E; Gladwin, Thomas E; Wiers, Reinout W

    2016-10-01

    Cognitive bias modification (CBM) can be used to retrain automatic approach tendencies for alcohol. We investigated whether changing cortical excitability with transcranial direct current stimulation (tDCS) could enhance CBM effects in hazardous drinkers. We also studied the underlying mechanisms by including behavioral (craving, implicit associations, approach tendencies) and electrophysiological (event-related potentials) measurements. The analytical sample consisted of 78 hazardous drinkers (Alcohol Use Disorders Identification Test >8) randomly assigned to 4 conditions in a 2-by-2 factorial design (control/active CBM and sham/active tDCS). The intervention consisted of 3 sessions of CBM, specifically alcohol approach bias retraining, combined with 15 minutes 1 mA tDCS over the left dorsolateral prefrontal cortex. There was a pre- and postassessment before and after the intervention that included experimental tasks (Approach Avoidance Task, Implicit Association Task) and an electroencephalogram with an oddball and cue-reactivity task. tDCS decreased cue-induced craving (but not overall craving) on postassessment. CBM did not induce an avoidance bias during assessment. During the training, active and control-CBM only differed in bias score during the first session. We found no enhancement effects of tDCS on CBM. Electrophysiological data showed no clear effects of active tDCS or CBM on the P300. There were no electrophysiological or behavioral effects of repeated CBM and/or tDCS, except for an effect of tDCS on craving. Applied in these specific ways these techniques appear to have limited effects in a hazardous drinking population. Copyright © 2016 by the Research Society on Alcoholism.

  7. 电网不对称故障下含飞轮储能单元的永磁直驱风电系统增强运行控制策略%Enhanced Control of Direct-Drive Permanent Magnet Wind Power Generation System Containing Flywheel Energy Storage Unit During Asymmetrical Fault in Power Grid

    Institute of Scientific and Technical Information of China (English)

    朱小军; 姚骏; 蒋昆; 夏先锋; 一宇; 龙虹毓

    2013-01-01

      The mechanism of DC bus voltage fluctuation in permanent magnet direct-drive wind power system containing flywheel energy storage unit during asymmetrical fault in power grid is analyzed, and on this basis an enhanced control strategy suitable to low-voltage ride through (LVRT) in such a wind power system is researched. Three selectable independent operating modes can be provided when the wind power system provides power grid transient reactive power support during asymmetrical fault in power grid by the proposed control strategy. The proposed control scheme surmounts the limitation of restraining DC-link voltage fluctuation by grid-connected converter under traditional control modes and leads proportional integral-resonant (PI-R) controller into closed-loop current control of flywheel motor to absorb double power frequency pulsating power in DC-link capacitor by flywheel energy storage unit, thus the stable control of DC-link voltage free of fluctuation during asymmetrical fault in power grid can be effectively implemented and further enhance LVRT ability of wind power system under asymmetrical fault in power grid. The correctness and effectiveness of the proposed control strategy are verified by Matlab/Simulink-based simulation results.%  分析了电网不对称故障下含飞轮储能单元的永磁直驱风电系统直流母线电压波动机理,在此基础上,研究了适用于该类型风电系统低电压穿越增强运行控制策略。所提控制策略在实现电网不对称故障下发电系统向电网提供暂态无功支持的同时,亦可提供3种可选的独立运行模式。所提控制方案突破传统控制模式下网侧变换器抑制直流链电压波动能力的局限,将比例积分谐振控制器(proportional integral resonant,PIR)引入飞轮电机电流闭环控制,利用飞轮储能单元吸收直流电容2倍工频脉动功率,从而有效实现故障过程中直流链电压的稳定无波动控制,进一

  8. The role of organizational virtuousness in organizational citizenship behavior of teachers: The test of direct and indirect effect through job satisfaction mediating

    Directory of Open Access Journals (Sweden)

    Kooshki Abedi Sara

    2016-01-01

    Full Text Available The aim of this study was to test the direct and indirect effect of organizational virtuousness in organizational citizenship behaviors of teachers and propose a model with a causal connection. The population consisted of all secondary school teachers of Karaj metropolitan areas where by cluster method sampling and Morgan table 403 people selected. The aim of this study is functional and in terms of methodology is survey. Standard questionnaires used to collect data and all of them had good reliability and validity. To analyze the data confirmatory factor analysis and structural equation modeling techniques used. The results showed that schools organizational virtuousness directly affect Less and non-significant on organizational citizenship behavior of teachers. The assumed test pattern suggests that organizational virtuousness with the mediation of job satisfaction can affect the behavior of teachers' organizational citizenship behavior. The findings of this study emphasis the importance of reinforcement of schools as well as teachers' job satisfaction and organizational virtuousness.

  9. Frequency and Characteristics Associated With Exposure to Tobacco Direct Mail Marketing and Its Prospective Effect on Smoking Behaviors Among Young Adults From the US Midwest

    Science.gov (United States)

    Forster, Jean L.

    2014-01-01

    Objectives. We examined the exposure to tobacco direct mail marketing and its effect on subsequent smoking behaviors in a US Midwest regional cohort of young adults. Methods. Data were collected from 2622 young adults (mean age = 24 years) in 2010 to 2011 (baseline) and 2011 to 2012 (follow-up). We collected information on demographics, tobacco use, and exposure to tobacco direct mail materials in the previous 6 months at baseline. Smoking behaviors were reassessed at follow-up. We investigated the characteristics associated with receiving these materials at baseline, and the associations between receiving cigarette coupons in the mail at baseline and smoking behaviors at follow-up. Results. Thirteen percent of participants reported receiving tobacco direct mail materials in the previous 6 months. Receipt of these materials was associated with age, education, and tobacco use (P marketing strategy might reduce the prevalence of smoking in this population. PMID:25211739

  10. Neonatal lesions of orbital frontal areas 11/13 in monkeys alter goal-directed behavior but spare fear conditioning and safety signal learning.

    Directory of Open Access Journals (Sweden)

    Andy M Kazama

    2014-03-01

    Full Text Available Recent studies in monkeys have demonstrated that damage to the lateral subfields of orbital frontal cortex (OFC areas 11/13 yields profound changes in flexible modulation of goal-directed behaviors and a lack in fear regulation. Yet, little consideration has been placed on its role in emotional and social development throughout life. The current study investigated the effects of neonatal lesions of the OFC on the flexible modulation of goal-directed behaviors and fear responses in monkeys. Infant monkeys received neonatal lesions of OFC areas 11/13 or sham-lesions during the first post-natal week. Modulation of goal-directed behaviors was measured with a devaluation task at 3-4 years and 6-7 years. Modulation of fear reactivity by safety signals was assessed with the AX+/BX- potentiated-startle paradigm at 6-7 years. Similar to adult-onset OFC lesions, selective neonatal lesions of OFC areas 11/13 yielded a failure to modulate behavioral responses guided by changes in reward value, but spared the ability to modulate fear responses in the presence of safety signals. These results suggest that these areas play a critical role in the development of behavioral adaptation during goal-directed behaviors, but not, or less so, in the development of the ability to process emotionally salient stimuli and to modulate emotional reactivity using environmental contexts, which could be supported by other OFC subfields, such as the most ventromedial subfields (i.e. areas 14/25. Given similar impaired decision-making abilities and spared modulation of fear followed both neonatal lesions of either OFC areas 11 and 13 or amygdala (Kazama et al., 2012; Kazama & Bachevalier, 2013, the present results suggest that interactions between these two neural structures play a critical role in the development of behavioral adaptation; an ability essential for the self-regulation of emotion and behavior that assures the maintenance of successful social relationships.

  11. Cost Behavior

    DEFF Research Database (Denmark)

    Hoffmann, Kira

    The objective of this dissertation is to investigate determinants and consequences of asymmetric cost behavior. Asymmetric cost behavior arises if the change in costs is different for increases in activity compared to equivalent decreases in activity. In this case, costs are termed “sticky......” if the change is less when activity falls than when activity rises, whereas costs are termed “anti-sticky” if the change is more when activity falls than when activity rises. Understanding such cost behavior is especially relevant for decision-makers and financial analysts that rely on accurate cost information...... to facilitate resource planning and earnings forecasting. As such, this dissertation relates to the topic of firm profitability and the interpretation of cost variability. The dissertation consists of three parts that are written in the form of separate academic papers. The following section briefly summarizes...

  12. Analysis of Ignition Behavior in a Turbocharged Direct Injection Dual Fuel Engine Using Propane and Methane as Primary Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2013-05-24

    This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (© pilot ¼ 0.2-0.6 and © overall ¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant © pilot (> 0.5), increasing © overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing © overall (at constant © pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

  13. Simulating bi-directional pedestrian flow in a cellular automaton model considering the body-turning behavior

    Science.gov (United States)

    Jin, Cheng-Jie; Jiang, Rui; Yin, Jun-Lin; Dong, Li-Yun; Li, Dawei

    2017-09-01

    In the experiments of bi-directional pedestrian flow, it is often observed that pedestrians turn their bodies and change from walking straight to walking sideways, in order to mitigate or avoid the conflicts with opposite walking ones. When these conflicts disappear, pedestrians restore and walk straight again. In the turning states, the forward velocities of pedestrians are not affected. In order to simulate this body-turning behavior, we use a cellular automaton (CA) model named ITP model, which has been proposed before. But the occupied area of one pedestrian is set as 0.4 m∗0.2 m. After the introduction of new rules of turnings and restorations, the pedestrians become more intelligent and flexible during the lane formation process, and some improvements of the fundamental diagram of pedestrian flow can be found. The simulation results of two different scenarios under open boundary conditions are also presented, and compared with the experimental data. It is shown that the new model performs much better than the original model in various tests, which further confirms the validity of the new rules. We think this approach is one useful contribution to the pedestrian flow modeling.

  14. Elicited Bid Functions in a (a)Symmetric First-Price Auctions

    NARCIS (Netherlands)

    Pezanis-Christou, P.; Sadrieh, A.

    2003-01-01

    We report on a series of experiments that examine bidding behavior in first-price sealed bid auctions with symmetric and asymmetric bidders.To study the extent of strategic behavior, we use an experimental design that elicits bidders complete bid functions in each round (auction) of the

  15. Asymmetric Schiff bases derived from diaminomaleonitrile and their metal complexes

    Science.gov (United States)

    Yang, Jianjie; Shi, Rufei; Zhou, Pei; Qiu, Qiming; Li, Hui

    2016-02-01

    Asymmetric Schiff bases, due to its asymmetric structure, can be used as asymmetric catalyst, antibacterial, and mimic molecules during simulate biological processes, etc. In recent years, research on synthesis and properties of asymmetric Schiff bases have become an increase interest of chemists. This review summarizes asymmetric Schiff bases derived from diaminomaleonitrile (DAMN) and DAMN-based asymmetric Schiff bases metal complexes. Applications of DAMN-based asymmetric Schiff bases are also discussed in this review.

  16. Ventrolateral Striatal Medium Spiny Neurons Positively Regulate Food-Incentive, Goal-Directed Behavior Independently of D1 and D2 Selectivity.

    Science.gov (United States)

    Natsubori, Akiyo; Tsutsui-Kimura, Iku; Nishida, Hiroshi; Bouchekioua, Youcef; Sekiya, Hiroshi; Uchigashima, Motokazu; Watanabe, Masahiko; de Kerchove d'Exaerde, Alban; Mimura, Masaru; Takata, Norio; Tanaka, Kenji F

    2017-03-08

    The ventral striatum is involved in motivated behavior. Akin to the dorsal striatum, the ventral striatum contains two parallel pathways: the striatomesencephalic pathway consisting of dopamine receptor Type 1-expressing medium spiny neurons (D1-MSNs) and the striatopallidal pathway consisting of D2-MSNs. These two genetically identified pathways are thought to encode opposing functions in motivated behavior. It has also been reported that D1/D2 genetic selectivity is not attributed to the anatomical discrimination of two pathways. We wanted to determine whether D1- and D2-MSNs in the ventral striatum functioned in an opposing manner as previous observations claimed, and whether D1/D2 selectivity corresponded to a functional segregation in motivated behavior of mice. To address this question, we focused on the lateral portion of ventral striatum as a region implicated in food-incentive, goal-directed behavior, and recorded D1 or D2-MSN activity by using a gene-encoded ratiometric Ca(2+) indicator and by constructing a fiberphotometry system, and manipulated their activities via optogenetic inhibition during ongoing behaviors. We observed concurrent event-related compound Ca(2+) elevations in ventrolateral D1- and D2-MSNs, especially at trial start cue-related and first lever press-related times. D1 or D2 selective optogenetic inhibition just after the trial start cue resulted in a reduction of goal-directed behavior, indicating a shared coding of motivated behavior by both populations at this time. Only D1-selective inhibition just after the first lever press resulted in the reduction of behavior, indicating D1-MSN-specific coding at that specific time. Our data did not support opposing encoding by both populations in food-incentive, goal-directed behavior.SIGNIFICANCE STATEMENT An opposing role of dopamine receptor Type 1 or Type 2-expressing medium spiny neurons (D1-MSNs or D2-MSNs) on striatum-mediated behaviors has been widely accepted. However, this idea has

  17. An analytic solution to asymmetrical bending problem of diaphragm coupling

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Because rigidity of either hub or rim of diaphragm coupling is much greater than that of the disk, and asymmetrical bending is under the condition of high speed revolution, an assumption is made that each circle in the middle plane before deforma-tion keeps its radius unchanged after deformation, but the plane on which the circle lies has a varying deflecting angle. Based on this assumption, and according to the principle of energy variation, the corresponding Euler's equation can be obtained, which has the primary integral. By neglecting some subsidiary factors, an analytic solution is obtained. Applying these formulas to a hyperbolic model of diaphragm, the results show that the octahedral shear stress varies less along either radial or thickness direction, but fluctu-ates greatly and periodically along circumferential direction. Thus asymmetrical bending significantly affects the material's fatigue.

  18. Quality Prediction of Asymmetrically Distorted Stereoscopic 3D Images.

    Science.gov (United States)

    Wang, Jiheng; Rehman, Abdul; Zeng, Kai; Wang, Shiqi; Wang, Zhou

    2015-11-01

    Objective quality assessment of distorted stereoscopic images is a challenging problem, especially when the distortions in the left and right views are asymmetric. Existing studies suggest that simply averaging the quality of the left and right views well predicts the quality of symmetrically distorted stereoscopic images, but generates substantial prediction bias when applied to asymmetrically distorted stereoscopic images. In this paper, we first build a database that contains both single-view and symmetrically and asymmetrically distorted stereoscopic images. We then carry out a subjective test, where we find that the quality prediction bias of the asymmetrically distorted images could lean toward opposite directions (overestimate or underestimate), depending on the distortion types and levels. Our subjective test also suggests that eye dominance effect does not have strong impact on the visual quality decisions of stereoscopic images. Furthermore, we develop an information content and divisive normalization-based pooling scheme that improves upon structural similarity in estimating the quality of single-view images. Finally, we propose a binocular rivalry-inspired multi-scale model to predict the quality of stereoscopic images from that of the single-view images. Our results show that the proposed model, without explicitly identifying image distortion types, successfully eliminates the prediction bias, leading to significantly improved quality prediction of the stereoscopic images.

  19. Research on the Design and Modification of Asymmetric Spur Gear

    Directory of Open Access Journals (Sweden)

    Xiaohe Deng

    2015-01-01

    Full Text Available A design method for the geometric shape and modification of asymmetric spur gear was proposed, in which the geometric shape and modification of the gear can be obtained directly according to the rack-cutter profile. In the geometric design process of the gear, a rack-cutter with different pressure angles and fillet radius in the driving side and coast side was selected, and the generated asymmetric spur gear profiles also had different pressure angles and fillets accordingly. In the modification design of the gear, the pressure angle modification of rack-cutter was conducted firstly and then the corresponding modified involute gear profile was obtained. The geometric model of spur gears was developed using computer-aided design, and the meshing process was analyzed using finite element simulation method. Furthermore, the transmission error and load sharing ratio of unmodified and modified asymmetric spur gears were investigated. Research results showed that the proposed gear design method was feasible and desired spur gear can be obtained through one time rapid machining by the method. Asymmetric spur gear with better transmission characteristic can be obtained via involute modification.

  20. D-Cycloserine Augmentation of Cognitive-Behavioral Therapy: Directions for Pilot Research in Pediatric Obsessive-Compulsive Disorder

    Science.gov (United States)

    Storch, Eric A.; McKay, Dean; Reid, Jeannette M.; Geller, Daniel A.; Goodman, Wayne K.; Lewin, Adam B.; Murphy, Tanya K.

    2010-01-01

    This paper discusses a recent translational success in combining behavioral psychotherapy with a novel medication, d-cycloserine (DCS), to augment cognitive-behavioral therapy (CBT) for anxiety disorders. The literature on behavioral theory of exposure-based therapies is provided, followed by a discussion of the role of DCS in enhancing extinction…