17,836 research outputs found

    Langevin Trajectories between Fixed Concentrations

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    We consider the trajectories of particles diffusing between two infinite baths of fixed concentrations connected by a channel, e.g. a protein channel of a biological membrane. The steady state influx and efflux of Langevin trajectories at the boundaries of a finite volume containing the channel and parts of the two baths is replicated by termination of outgoing trajectories and injection according to a residual phase space density. We present a simulation scheme that maintains averaged fixed concentrations without creating spurious boundary layers, consistent with the assumed physics

    Latent awareness: Early conscious access to motor preparation processes is linked to the readiness potential

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    An experience of intention to move accompanies execution of some voluntary actions. The Readiness Potential (RP) is an increasing negativity over motor brain areas prior to voluntary movement. Classical studies suggested that the RP starts before intention is consciously accessed as measured by offline recall-based reports, yet the interpretation of the RP and its temporal relation to awareness of intention remain controversial. We designed a task in which self-paced actions could be interrupted at random times by a visual cue that probed online awareness of intention. Participants were instructed to respond by pressing a key if they felt they were actively preparing a self-paced movement at the time of the cue (awareness report), but to ignore the cue otherwise. We show that an RP-like activity was more strongly present before the cue for probes eliciting awareness reports than otherwise. We further show that recall-based reports of the time of conscious intention are linked to visual attention processes, whereas online reports elicited by a probe are not. Our results suggest that awareness of intention is accessible at relatively early stages of motor preparation and that the RP is specifically associated with this conscious experience

    Strategi Pengembangan Agribisnis Puring di Desa Petiga, Kecamatan Marga, Kabupaten Tabanan

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    Croton (Codiaeum variegatum) has become a valuable ornamental plant because of the beauty of its colorful unique features of leaves that is worth to collect. Farmers from Petiga Village have been trying to develop croton as the object of business. A huge prospect of ornamental plant as the development in Bali emerging, bring hopes for the future of croton agribusiness. Yet, there are still many aspects that have to be taken into consideration in order to bring this business prospective especially to Petiga Village farmers. This research was conducted at Petiga Village, Marga District, Tabanan Regency with the aim at: (1) identifying internal factors (strengths and weaknesses) and external factors (opportunities and threats). (2) determining the position of the business, (3) formulating strategies that are relevant to be applied. Respondents of this research were determined on purpose, including the farmer, head of farmer groups, village agriculture field supervisor, and the head of Agriculture Departement from Tabanan Regency. Data analysis methods used were: (1) Analysis of IFE matrix, (2) Analysis of EFE matrix, (3) Analysis of the IE matrix, (4) SWOT Analysis, and (5) Analysis of AHP. The results of the study showed that the major constraint of the progress development of croton agribusiness at Petiga Village was that most of the farmer lack of information regarding the market and the price of the product. Only a small group of farmers had an access to the direct market of croton. The study also identify two major internal strengths : good quality product (croton) and the possibility of developing new variety of croton with better prices. While the external threats come from other kind of ornament plant and croton from other regions (East Java). SWOT analysis formulates four alternative strategies : improving the quantity and quality of the product, improving marketing and promotion, improving management and entrepreneurship skill of the farmer and improving coordination and consolidation among farmers. Analysist of Hierarchy Process found that improving management and entrepreneurship of the farmers had a higher priority above other alternative strategies. This strategy could be perform by delivering practical training and close supervision on the site to give them a direct benefit

    Generalized Riemann sums

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    The primary aim of this chapter is, commemorating the 150th anniversary of Riemann's death, to explain how the idea of {\it Riemann sum} is linked to other branches of mathematics. The materials I treat are more or less classical and elementary, thus available to the "common mathematician in the streets." However one may still see here interesting inter-connection and cohesiveness in mathematics

    Irreducible characters of GSp(4, q) and dimensions of spaces of fixed vectors

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    In this paper, we compute the conjugacy classes and the list of irreducible characters of GSp(4,q), where q is odd. We also determine precisely which irreducible characters are non-cuspidal and which are generic. These characters are then used to compute dimensions of certain subspaces of fixed vectors of smooth admissible non-supercuspidal representations of GSp(4,F), where F is a non-archimedean local field of characteristic zero with residue field of order q.Comment: 48 pages, 21 tables. Corrected an error in Table 16 for type V* representations (theta_11 and theta_12 were switched

    Focusing and Compression of Ultrashort Pulses through Scattering Media

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    Light scattering in inhomogeneous media induces wavefront distortions which pose an inherent limitation in many optical applications. Examples range from microscopy and nanosurgery to astronomy. In recent years, ongoing efforts have made the correction of spatial distortions possible by wavefront shaping techniques. However, when ultrashort pulses are employed scattering induces temporal distortions which hinder their use in nonlinear processes such as in multiphoton microscopy and quantum control experiments. Here we show that correction of both spatial and temporal distortions can be attained by manipulating only the spatial degrees of freedom of the incident wavefront. Moreover, by optimizing a nonlinear signal the refocused pulse can be shorter than the input pulse. We demonstrate focusing of 100fs pulses through a 1mm thick brain tissue, and 1000-fold enhancement of a localized two-photon fluorescence signal. Our results open up new possibilities for optical manipulation and nonlinear imaging in scattering media

    Spherical Relativistic Hartree theory in a Woods-Saxon basis

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    The Woods-Saxon basis has been suggested to replace the widely used harmonic oscillator basis for solving the relativistic mean field (RMF) theory in order to generalize it to study exotic nuclei. As examples, relativistic Hartree theory is solved for spherical nuclei in a Woods-Saxon basis obtained by solving either the Schr\"odinger equation or the Dirac equation (labelled as SRHSWS and SRHDWS, respectively and SRHWS for both). In SRHDWS, the negative levels in the Dirac Sea must be properly included. The basis in SRHDWS could be smaller than that in SRHSWS which will simplify the deformed problem. The results from SRHWS are compared in detail with those from solving the spherical relativistic Hartree theory in the harmonic oscillator basis (SRHHO) and those in the coordinate space (SRHR). All of these approaches give identical nuclear properties such as total binding energies and root mean square radii for stable nuclei. For exotic nuclei, e.g., 72^{72}Ca, SRHWS satisfactorily reproduces the neutron density distribution from SRHR, while SRHHO fails. It is shown that the Woods-Saxon basis can be extended to more complicated situations for exotic nuclei where both deformation and pairing have to be taken into account.Comment: 12 pages, 9 figure

    The significance of seniority for women managers’ interpretations of organizational restructuring

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    This paper examines the impact of restructuring within the transport and logistics sector on women managers working at senior and less senior (middle/junior management) levels of the organization. The majority of women experienced increased performance pressures and heavier workloads as well as an increase in working hours. At the same time, there were pressures to work at home (i.e. week-ends and evenings) and reduced opportunities to work from home (i.e. during normal office hours). Management level emerged as an important factor in how these changes were interpreted. Senior managers perceived more positive outcomes in terms of increased motivation and loyalty. Despite a longer working week, they were less likely to report low morale as an outcome from long hours. In fact, irrespective of management level, women working shorter hours were more likely to report low morale as an outcome. Results are discussed in relation to literature on restructuring and careers, in terms of perceptual framing and in relation to different levels of investment in the organization
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