WorldWideScience

Sample records for central pattern generators

  1. Central pattern generation underlying Limulus rhythmic behavior patterns

    Directory of Open Access Journals (Sweden)

    Gordon A. Wyse

    2010-10-01

    Full Text Available Many behavioral activities of the horseshoe crab Limulus are rhythmic, and most of these are produced in large part by central pattern generators within the CNS. The chain of opisthosomal (‘abdominal’ ganglia controls gill movements of ventilation and gill cleaning, and the prosomal ring of fused ganglia (brain and segmental ‘thoracic’ ganglia controls generation of feeding and locomotor movements of the legs. Both the opisthosomal CNS and the prosomal CNS can generate behaviorally appropriate patterns of motor output in isolation, without movements or sensory input. Preparations of the isolated opisthosomal CNS generate rhythmic output patterns of motor activity characterized as fictive ventilatory and gill cleaning rhythms. Moreover, CNS preparations also express longer-term patterns, such as intermittent ventilation or sequential bouts of ventilation and gill cleaning. Such longer-term patterns are commonly observed in intact animals. The isolated prosomal CNS does not spontaneously generate the activity patterns characteristic of walking, swimming, and feeding. However, perfusion of octopamine in the isolated prosomal CNS activates central pattern generators underlying rhythmic chewing movements, and injection of octopamine into intact Limulus promotes the chewing pattern of feeding, whether or not food is presented. Our understanding of the ability of neuromodulators such as octopamine to elicit or alter central motor programs may help to clarify the central neural circuits of pattern generation that produce and coordinate these rhythmic behaviors [Current Zoology 56 (5: 537–549, 2010].

  2. Evolution of central pattern generators and rhythmic behaviours.

    Science.gov (United States)

    Katz, Paul S

    2016-01-01

    Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization.

  3. Central Pattern Generator for Locomotion: Anatomical, Physiological and Pathophysiological Considerations

    Directory of Open Access Journals (Sweden)

    Pierre A. Guertin

    2013-02-01

    Full Text Available This article provides a perspective on major innovations over the past century in research on the spinal cord and, specifically, on specialized spinal circuits involved in the control of rhythmic locomotor pattern generation and modulation. Pioneers such as Charles Sherrington and Thomas Graham Brown have conducted experiments in the early twentieth century that changed our views of the neural control of locomotion. Their seminal work supported subsequently by several decades of evidence has led to the conclusion that walking, flying and swimming are largely controlled by a network of spinal neurons generally referred to as the central pattern generator (CPG for locomotion. It has been subsequently demonstrated across all vertebrate species examined, from lampreys to humans, that this CPG is capable, under some conditions, to self-produce, even in absence of descending or peripheral inputs, basic rhythmic and coordinated locomotor movements. Recent evidence suggests, in turn, that plasticity changes of some CPG elements may contribute to the development of specific pathophysiological conditions associated with impaired locomotion or spontaneous locomotor-like movements. This article constitutes a comprehensive review summarizing key findings on the CPG as well as on its potential role in Restless Leg Syndrome (RLS, Periodic Leg Movement (PLM, and Alternating Leg Muscle Activation (ALMA. Special attention will be paid to the role of the CPG in a recently identified, and uniquely different neurological disorder, called the Uner Tan Syndrome.

  4. Central pattern generator for locomotion: anatomical, physiological, and pathophysiological considerations.

    Science.gov (United States)

    Guertin, Pierre A

    2012-01-01

    This article provides a perspective on major innovations over the past century in research on the spinal cord and, specifically, on specialized spinal circuits involved in the control of rhythmic locomotor pattern generation and modulation. Pioneers such as Charles Sherrington and Thomas Graham Brown have conducted experiments in the early twentieth century that changed our views of the neural control of locomotion. Their seminal work supported subsequently by several decades of evidence has led to the conclusion that walking, flying, and swimming are largely controlled by a network of spinal neurons generally referred to as the central pattern generator (CPG) for locomotion. It has been subsequently demonstrated across all vertebrate species examined, from lampreys to humans, that this CPG is capable, under some conditions, to self-produce, even in absence of descending or peripheral inputs, basic rhythmic, and coordinated locomotor movements. Recent evidence suggests, in turn, that plasticity changes of some CPG elements may contribute to the development of specific pathophysiological conditions associated with impaired locomotion or spontaneous locomotor-like movements. This article constitutes a comprehensive review summarizing key findings on the CPG as well as on its potential role in Restless Leg Syndrome, Periodic Leg Movement, and Alternating Leg Muscle Activation. Special attention will be paid to the role of the CPG in a recently identified, and uniquely different neurological disorder, called the Uner Tan Syndrome.

  5. Symmetry in locomotor central pattern generators and animal gaits

    Science.gov (United States)

    Golubitsky, Martin; Stewart, Ian; Buono, Pietro-Luciano; Collins, J. J.

    1999-10-01

    Animal locomotion is controlled, in part, by a central pattern generator (CPG), which is an intraspinal network of neurons capable of generating a rhythmic output. The spatio-temporal symmetries of the quadrupedal gaits walk, trot and pace lead to plausible assumptions about the symmetries of locomotor CPGs. These assumptions imply that the CPG of a quadruped should consist of eight nominally identical subcircuits, arranged in an essentially unique matter. Here we apply analogous arguments to myriapod CPGs. Analyses based on symmetry applied to these networks lead to testable predictions, including a distinction between primary and secondary gaits, the existence of a new primary gait called `jump', and the occurrence of half-integer wave numbers in myriapod gaits. For bipeds, our analysis also predicts two gaits with the out-of-phase symmetry of the walk and two gaits with the in-phase symmetry of the hop. We present data that support each of these predictions. This work suggests that symmetry can be used to infer a plausible class of CPG network architectures from observed patterns of animal gaits.

  6. Topology of Central Pattern Generators Selection by Chaotic Neurons

    CERN Document Server

    Huerta, R; Rabinovich, M I; Abarbanel, Henry D I; Abarbanel, Henry D I

    1999-01-01

    Central Pattern Generators (CPGs) in invertebrates are comprised of networks of neurons in which every neuron has reciprocal connections to other members of the CPG. This is a ``closed'' network topology. An ``open'' topology, where one or more neurons receives input but does not send output to other member neurons, is not found in these CPGs. In this paper we investigate a possible reason for this topological structure using the ability to perform a biological functional task as a measure of the efficacy of the network. When the CPG is composed of model neurons which exhibit regular membrane voltage oscillations, open topologies are essentially as able to maximize this functionality as closed topologies. When we replace these models by neurons which exhibit chaotic membrane voltage oscillations, the functional criterion selects closed topologies when the demands of the task are increased, and these are the topologies observed in known CPG networks. As isolated neurons from invertebrate CPGs are known in some...

  7. Sexually differentiated central pattern generators in Xenopus laevis.

    Science.gov (United States)

    Zornik, Erik; Yamaguchi, Ayako

    2008-06-01

    Understanding the neural mechanisms that underlie the function of central pattern generators (CPGs) presents a formidable challenge requiring sophisticated tools and well-chosen model systems. In this article, we describe recent work on vocalizations of the African clawed frog Xenopus laevis. These behaviors are driven by sexually differentiated CPGs and are exceptionally well suited to this objective. In particular, a simplified mechanism of vocal production (independent of respiratory musculature) allows straightforward interpretations of nerve activity with respect to behavior. Furthermore, the development of a fictively vocalizing isolated brain, together with the finding of rapid androgen-induced masculinization of female vocalizations, provides an invaluable tool for determining how new behaviors arise from existing circuits. PMID:18471902

  8. Central Pattern Generation and the Motor Infrastructure for Suck, Respiration, and Speech

    Science.gov (United States)

    Barlow, Steven M.; Estep, Meredith

    2006-01-01

    The objective of the current report is to review experimental findings on centrally patterned movements and sensory and descending modulation of central pattern generators (CPGs) in a variety of animal and human models. Special emphasis is directed toward speech production muscle systems, including the chest wall and orofacial complex during…

  9. Energy efficient and robust rhythmic limb movement by central pattern generators

    NARCIS (Netherlands)

    Verdaasdonk, B.W.; Koopman, H.F.J.M.; Helm, van der F.C.T.

    2006-01-01

    Humans show great energy efficiency and robustness in rhythmic tasks, such as walking and arm swinging. In this study a mathematical model of rhythmic limb movement is presented, which shows that tight local coupling of Central Pattern Generators (CPGs) to limbs could explain part of this behavior.

  10. Energy efficient walking with central pattern generators: from passive dynamic walking to biologically inspired control

    NARCIS (Netherlands)

    Verdaasdonk, B.W.; Koopman, H.F.J.M.; Van der Helm, F.C.T.

    2009-01-01

    Like human walking, passive dynamic walking—i.e. walking down a slope with no actuation except gravity—is energy efficient by exploiting the natural dynamics. In the animal world, neural oscillators termed central pattern generators (CPGs) provide the basic rhythm for muscular activity in locomotion

  11. Xenopus Vocalizations Are Controlled by a Sexually Differentiated Hindbrain Central Pattern Generator

    OpenAIRE

    Rhodes, Heather J.; Yu, Heather J.; YAMAGUCHI, ayako

    2007-01-01

    Male and female African clawed frogs (Xenopus laevis) produce rhythmic, sexually distinct vocalizations as part of courtship and mating. We found that Xenopus vocal behavior is governed by a sexually dimorphic central pattern generator (CPG) and that fictive vocalizations can be elicited from an in vitro brain preparation by application of serotonin or by electrical stimulation of a premotor nucleus. Male brains produced fictive vocal patterns representing two calls commonly produced by males...

  12. Design of a central pattern generator using reservoir computing for learning human motion

    OpenAIRE

    Wyffels, Francis; Schrauwen, Benjamin

    2009-01-01

    To generate coordinated periodic movements, robot locomotion demands mechanisms which are able to learn and produce stable rhythmic motion in a controllable way. Because systems based on biological central pattern generators (CPGs) can cope with these demands, these kind of systems are gaining in success. In this work we introduce a novel methodology that uses the dynamics of a randomly connected recurrent neural network for the design of CPGs. When a randomly connected recurrent neural netwo...

  13. Sensor-Based Programming of Central Pattern Generators in Humanoid Robots

    Directory of Open Access Journals (Sweden)

    Hamed Shahbazi

    2013-04-01

    Full Text Available In the present article, a method for generating curvilinear bipedal walking patterns is proposed which is able to generate rhythmic and periodic trajectories for a Nao soccer player robot. To do so, a programmable central pattern generator was used which was inspired from locomotion structures in vertebrate animals. In this paper, the programmable central pattern generators were extended and new Equations were added to make a curvilinear pattern for walking Nao robots on a specified circular curve. In addition, some specific Equations were added to the model to control the arms and synchronize them with the movement of the feet. The model uses some sensory inputs to obtain some feedback from the movement and adjust it conforming to the potential perturbations. Input sensory values consist of accelerator values and foot pressure sensor values located on the bottom of each foot. Feedback values can adopt walking to some desired specifications and compensate the effects of some types of perturbations. The proposed model has many benefits including smooth walking patterns and modulation during walking. This model can be extended and used in the Nao soccer player both for the standard platform and the 3D soccer simulation leagues of Robocup SPL competitions to train different types of motions.

  14. From Spinal Central Pattern Generators to Cortical Network: Integrated BCI for Walking Rehabilitation

    Directory of Open Access Journals (Sweden)

    G. Cheron

    2012-01-01

    Full Text Available Success in locomotor rehabilitation programs can be improved with the use of brain-computer interfaces (BCIs. Although a wealth of research has demonstrated that locomotion is largely controlled by spinal mechanisms, the brain is of utmost importance in monitoring locomotor patterns and therefore contains information regarding central pattern generation functioning. In addition, there is also a tight coordination between the upper and lower limbs, which can also be useful in controlling locomotion. The current paper critically investigates different approaches that are applicable to this field: the use of electroencephalogram (EEG, upper limb electromyogram (EMG, or a hybrid of the two neurophysiological signals to control assistive exoskeletons used in locomotion based on programmable central pattern generators (PCPGs or dynamic recurrent neural networks (DRNNs. Plantar surface tactile stimulation devices combined with virtual reality may provide the sensation of walking while in a supine position for use of training brain signals generated during locomotion. These methods may exploit mechanisms of brain plasticity and assist in the neurorehabilitation of gait in a variety of clinical conditions, including stroke, spinal trauma, multiple sclerosis, and cerebral palsy.

  15. Sequential developmental acquisition of neuromodulatory inputs to a central pattern-generating network.

    Science.gov (United States)

    Fénelon, V S; Kilman, V; Meyrand, P; Marder, E

    1999-06-01

    The activity of the adult stomatogastric ganglion (STG) depends on a large number of aminergic and peptidergic modulatory inputs. Our aim is to understand the role of these modulatory inputs in the development of the central pattern-generating networks of the STG. Therefore, we analyze the developmental and adult expressions of three neuropeptides in the stomatogastric nervous system of the lobsters Homarus americanus and Homarus gammarus by using wholemount immunocytochemistry and confocal microscopy. In adults, red pigment-concentrating hormone (RPCH)-like, proctolin-like, and a tachykinin-like immunoreactivity are present in axonal projections to the STG. At 50% of embryonic development (E50), all three peptides stain the commissural ganglia and brain, but only RPCH- and proctolin-like immunoreactivities stain axonal arbors in the STG. Tachykinin-like immunoreactivity is not apparent in the STG until larval stage II (LII). The RPCH-immunoreactive projection to the STG consists of two pairs of fibers. One pair stains for RPCH immunoreactivity at E50; the second RPCH-immunoreactive pair does not stain until about LII. One pair of the RPCH fibers double labels for tachykinin-like immunoreactivity. The adult complement of neuromodulatory inputs is not fully expressed until close to the developmental time at which major changes in the STG motor patterns occur, suggesting that neuromodulators play a role in the tuning of the central pattern generators during development. PMID:10340510

  16. Central generation of grooming motor patterns and interlimb coordination in locusts.

    Science.gov (United States)

    Berkowitz, A; Laurent, G

    1996-12-15

    Coordinated bursts of leg motoneuron activity were evoked in locusts with deefferented legs by tactile stimulation of sites that evoke grooming behavior. This suggests that insect thoracic ganglia contain central pattern generators for directed leg movements. Motoneuron recordings were made from metathoracic and mesothoracic nerves, after eliminating all leg motor innervation, as well as all input from the brain, subesophageal ganglion, and prothoracic ganglion. Strong, brief trochanteral levator motoneuron bursts occurred, together with silence of the slow and fast trochanteral depressor motoneurons and activation of the common inhibitor motoneuron. The metathoracic slow tibial extensor motoneuron was active in a pattern distinct from its activity during walking or during rhythms evoked by the muscarinic agonist pilocarpine. Preparations in which the metathoracic ganglion was isolated from all other ganglia could still produce fictive motor patterns in response to tactile stimulation of metathoracic locations. Bursts of trochanteral levator and depressor motoneurons were clearly coordinated between the left and right metathoracic hemiganglia and also between the mesothoracic and the ipsilateral metathoracic ganglia. These data provide clear evidence for centrally generated interlimb coordination in an insect.

  17. Study on dynamics of central pattern generator model for a quadrupedal robot

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiuli; Zheng Haojun

    2007-01-01

    Based on Matsuoka's central pattern generator(CPG)model and taking quadmped as an example,the dynamics of CPG model was investigated throush the single-parameter-analysis method and the numerical simulation technique.Simulation results indicate that the CPG model exhibits complex dynamics,while each parameter has specifically definitive influenco trends on the CPG output.These conclusions re applied to control a quadrupedal robot to walk in different gaits,clear obstacle,and walk up-and down-slope successfully.

  18. Global stability of synchronous and out-of-phase oscillations in central pattern generators

    CERN Document Server

    Landsman, A S

    2010-01-01

    Coupled arrays of Andronov-Hopf oscillators are investigated. These arrays can be diffusively or repulsively coupled, and can serve as central pattern generator models in animal locomotion and robotics. It is shown that repulsive coupling generates out-of-phase oscillations, while diffusive coupling generates synchronous oscillations. Specifically, symmetric solutions and their corresponding amplitudes are derived, and contraction analysis is used to prove global stability and convergence of oscillations to either symmetric out-of-phase or synchronous states, depending on the coupling constant. Next, the two mechanisms are used jointly by coupling multiple arrays. The resulting dynamics is analyzed, in a model inspired by the CPG-motorneuron network that controls the heartbeat of a medicinal leech.

  19. Localization of Motor Neurons and Central Pattern Generators for Motor Patterns Underlying Feeding Behavior in Drosophila Larvae.

    Directory of Open Access Journals (Sweden)

    Sebastian Hückesfeld

    Full Text Available Motor systems can be functionally organized into effector organs (muscles and glands, the motor neurons, central pattern generators (CPG and higher control centers of the brain. Using genetic and electrophysiological methods, we have begun to deconstruct the motor system driving Drosophila larval feeding behavior into its component parts. In this paper, we identify distinct clusters of motor neurons that execute head tilting, mouth hook movements, and pharyngeal pumping during larval feeding. This basic anatomical scaffold enabled the use of calcium-imaging to monitor the neural activity of motor neurons within the central nervous system (CNS that drive food intake. Simultaneous nerve- and muscle-recordings demonstrate that the motor neurons innervate the cibarial dilator musculature (CDM ipsi- and contra-laterally. By classical lesion experiments we localize a set of CPGs generating the neuronal pattern underlying feeding movements to the subesophageal zone (SEZ. Lesioning of higher brain centers decelerated all feeding-related motor patterns, whereas lesioning of ventral nerve cord (VNC only affected the motor rhythm underlying pharyngeal pumping. These findings provide a basis for progressing upstream of the motor neurons to identify higher regulatory components of the feeding motor system.

  20. Key bifurcations of bursting polyrhythms in 3-cell central pattern generators.

    Directory of Open Access Journals (Sweden)

    Jeremy Wojcik

    Full Text Available We identify and describe the key qualitative rhythmic states in various 3-cell network motifs of a multifunctional central pattern generator (CPG. Such CPGs are neural microcircuits of cells whose synergetic interactions produce multiple states with distinct phase-locked patterns of bursting activity. To study biologically plausible CPG models, we develop a suite of computational tools that reduce the problem of stability and existence of rhythmic patterns in networks to the bifurcation analysis of fixed points and invariant curves of a Poincaré return maps for phase lags between cells. We explore different functional possibilities for motifs involving symmetry breaking and heterogeneity. This is achieved by varying coupling properties of the synapses between the cells and studying the qualitative changes in the structure of the corresponding return maps. Our findings provide a systematic basis for understanding plausible biophysical mechanisms for the regulation of rhythmic patterns generated by various CPGs in the context of motor control such as gait-switching in locomotion. Our analysis does not require knowledge of the equations modeling the system and provides a powerful qualitative approach to studying detailed models of rhythmic behavior. Thus, our approach is applicable to a wide range of biological phenomena beyond motor control.

  1. Biological oscillations for learning walking coordination: dynamic recurrent neural network functionally models physiological central pattern generator.

    Science.gov (United States)

    Hoellinger, Thomas; Petieau, Mathieu; Duvinage, Matthieu; Castermans, Thierry; Seetharaman, Karthik; Cebolla, Ana-Maria; Bengoetxea, Ana; Ivanenko, Yuri; Dan, Bernard; Cheron, Guy

    2013-01-01

    The existence of dedicated neuronal modules such as those organized in the cerebral cortex, thalamus, basal ganglia, cerebellum, or spinal cord raises the question of how these functional modules are coordinated for appropriate motor behavior. Study of human locomotion offers an interesting field for addressing this central question. The coordination of the elevation of the 3 leg segments under a planar covariation rule (Borghese et al., 1996) was recently modeled (Barliya et al., 2009) by phase-adjusted simple oscillators shedding new light on the understanding of the central pattern generator (CPG) processing relevant oscillation signals. We describe the use of a dynamic recurrent neural network (DRNN) mimicking the natural oscillatory behavior of human locomotion for reproducing the planar covariation rule in both legs at different walking speeds. Neural network learning was based on sinusoid signals integrating frequency and amplitude features of the first three harmonics of the sagittal elevation angles of the thigh, shank, and foot of each lower limb. We verified the biological plausibility of the neural networks. Best results were obtained with oscillations extracted from the first three harmonics in comparison to oscillations outside the harmonic frequency peaks. Physiological replication steadily increased with the number of neuronal units from 1 to 80, where similarity index reached 0.99. Analysis of synaptic weighting showed that the proportion of inhibitory connections consistently increased with the number of neuronal units in the DRNN. This emerging property in the artificial neural networks resonates with recent advances in neurophysiology of inhibitory neurons that are involved in central nervous system oscillatory activities. The main message of this study is that this type of DRNN may offer a useful model of physiological central pattern generator for gaining insights in basic research and developing clinical applications.

  2. Biological oscillations for learning walking coordination: dynamic recurrent neural network functionally models physiological central pattern generator

    Directory of Open Access Journals (Sweden)

    Thomas eHoellinger

    2013-05-01

    Full Text Available The existence of dedicated neuronal modules such as those organized in the cerebral cortex, thalamus, basal ganglia, cerebellum or spinal cord raises the question of how these functional modules are coordinated for appropriate motor behavior. Study of human locomotion offers an interesting field for addressing this central question. The coordination of the elevation of the 3 leg segments under a planar covariation rule (Borghese et al., 1996 was recently modeled (Barliya et al., 2009 by phase-adjusted simple oscillators shedding new light on the understanding of the central pattern generator processing relevant oscillation signals. We describe the use of a dynamic recurrent neural network (DRNN mimicking the natural oscillatory behavior of human locomotion for reproducing the planar covariation rule in both legs at different walking speeds. Neural network learning was based on sinusoid signals integrating frequency and amplitude features of the first three harmonics of the sagittal elevation angles of the thigh, shank and foot of each lower limb. We verified the biological plausibility of the neural networks. Best results were obtained with oscillations extracted from the first three harmonics in comparison to oscillations outside the harmonic frequency peaks. Physiological replication steadily increased with the number of neuronal units from 1 to 80, where similarity index reached 0.99. Analysis of synaptic weighting showed that the proportion of inhibitory connections consistently increased with the number of neuronal units in the DRNN. This emerging property in the artificial neural networks resonates with recent advances in neurophysiology of inhibitory neurons that are involved in central nervous system oscillatory activities. The main message of this study is that this type of DRNN may offer a useful model of physiological central pattern generator for gaining insights in basic research and developing clinical applications.

  3. Coupled chaotic oscillators and their relation to a central pattern generator for artificial quadrupeds

    Indian Academy of Sciences (India)

    Horacio Castellini; Efta Yudiarsah; Lilia Romanelli; Hilda A Cerdeira

    2005-04-01

    Animal locomotion employs different periodic patterns known as animal gaits. In 1993, Collins and Stewart recognized that gaits possessed certain symmetries and characterized the gaits of quadrupeds and bipeds using permutation symmetry groups, which impose constraints on the locomotion center called the central pattern generator (CPG) in the animal brain. They modeled the CPG by coupling four nonlinear oscillators and found that it was possible to reproduce all symmetries of the gaits by changing the coupling strength. Here we propose to extend this idea using coupled chaotic oscillators synchronized using the Pyragas method in order to characterize the CPG symmetries. We also evaluate the time series behavior when the foot is in contact with the ground: this has potential robotic applications.

  4. Bio-inspired Optimal Locomotion Reconfigurability of Quadruped Rovers using Central Pattern Generators

    Science.gov (United States)

    Bohra, Murtaza

    Legged rovers are often considered as viable solutions for traversing unknown terrain. This work addresses the optimal locomotion reconfigurability of quadruped rovers, which consists of obtaining optimal locomotion modes, and transitioning between them. A 2D sagittal plane rover model is considered based on a domestic cat. Using a Genetic Algorithm, the gait, pose and control variables that minimize torque or maximize speed are found separately. The optimization approach takes into account the elimination of leg impact, while considering the entire variable spectrum. The optimal solutions are consistent with other works on gait optimization, and are similar to gaits found in quadruped animals as well. An online model-free gait planning framework is also implemented, that is based on Central Pattern Generators is implemented. It is used to generate joint and control trajectories for any arbitrarily varying speed profile, and shown to regulate locomotion transition and speed modulation, both endogenously and continuously.

  5. Toward robust phase-locking in Melibe swim central pattern generator models

    Science.gov (United States)

    Jalil, Sajiya; Allen, Dane; Youker, Joseph; Shilnikov, Andrey

    2013-12-01

    Small groups of interneurons, abbreviated by CPG for central pattern generators, are arranged into neural networks to generate a variety of core bursting rhythms with specific phase-locked states, on distinct time scales, which govern vital motor behaviors in invertebrates such as chewing and swimming. These movements in lower level animals mimic motions of organs in higher animals due to evolutionarily conserved mechanisms. Hence, various neurological diseases can be linked to abnormal movement of body parts that are regulated by a malfunctioning CPG. In this paper, we, being inspired by recent experimental studies of neuronal activity patterns recorded from a swimming motion CPG of the sea slug Melibe leonina, examine a mathematical model of a 4-cell network that can plausibly and stably underlie the observed bursting rhythm. We develop a dynamical systems framework for explaining the existence and robustness of phase-locked states in activity patterns produced by the modeled CPGs. The proposed tools can be used for identifying core components for other CPG networks with reliable bursting outcomes and specific phase relationships between the interneurons. Our findings can be employed for identifying or implementing the conditions for normal and pathological functioning of basic CPGs of animals and artificially intelligent prosthetics that can regulate various movements.

  6. A model of a flexible anguilliform swimmer driven by a central pattern generator with proprioceptive feedback

    Science.gov (United States)

    Hamlet, Christina; Tytell, Eric; Hoffman, Kathleen; Fauci, Lisa

    2015-11-01

    The swimming of a simple vertebrate, the lamprey, can shed light on how a flexible body can couple with a fluid environment to swim rapidly and efficiently. Animals use proprioceptive sensory information to sense how their bodies are bending, and then adjust the neural signals to their muscles to improve performance. We will present recent progress in the development of a computational model of a lamprey swimming in a Navier-Stokes fluid where a simple central pattern generator model, based on phase oscillators, is coupled to the evolving body dynamics of the swimmer through curvature and curvature derivative feedback. Such feedback can be positive (frequency decreasing), negative (frequency increasing), or mixed (positive to one side of the body and negative to the other, or vice versa). We will examine how the emergent swimming behavior and cost of transport depends upon these functional forms of proprioceptive feedback chosen in the model.

  7. Emergent Central Pattern Generator Behavior in Gap-Junction-Coupled Hodgkin-Huxley Style Neuron Model

    Directory of Open Access Journals (Sweden)

    Kyle G. Horn

    2012-01-01

    Full Text Available Most models of central pattern generators (CPGs involve two distinct nuclei mutually inhibiting one another via synapses. Here, we present a single-nucleus model of biologically realistic Hodgkin-Huxley neurons with random gap junction coupling. Despite no explicit division of neurons into two groups, we observe a spontaneous division of neurons into two distinct firing groups. In addition, we also demonstrate this phenomenon in a simplified version of the model, highlighting the importance of afterhyperpolarization currents ( to CPGs utilizing gap junction coupling. The properties of these CPGs also appear sensitive to gap junction conductance, probability of gap junction coupling between cells, topology of gap junction coupling, and, to a lesser extent, input current into our simulated nucleus.

  8. Reticular activating system of a central pattern generator: premovement electrical potentials.

    Science.gov (United States)

    Tapia, Jesus A; Trejo, Argelia; Linares, Pablo; Alva, J Manuel; Kristeva, Rumyana; Manjarrez, Elias

    2013-10-01

    For the first time, here we characterize a bulbar reticular activating system (RAS) of neurons in decerebrate, deafferented and decerebellated cats producing a premovement electrical potential that we named obex slow potential (OSP). The OSP occurs about 0.8 ± 0.4 sec prior to the onset of a fictive-scratching-episode. Here, we describe two classes of bulbar neurons, off-on, which are silent but exhibit a 80 ± 56 Hz firing discharge at the beginning of (and during) the OSP, and on-off interneurons, with a 27 ± 14 Hz firing activity that stops at the beginning of (and during) the OSP. We suggest that these OSP-associated neurons belong to a descending RAS, which contributes to the activation of the spinal central pattern generators.

  9. Intersegmental coordination of cockroach locomotion: adaptive control of centrally coupled pattern generator circuits

    Directory of Open Access Journals (Sweden)

    Einat eFuchs

    2011-01-01

    Full Text Available Animals’ ability to demonstrate both stereotyped and adaptive locomotor behavior is largely dependent on the interplay between centrally-generated motor patterns and the sensory inputs that shape them. We utilized a combined experimental and theoretical approach to investigate the relative importance of CPG interconnections vs. intersegmental afferents in the cockroach: an animal that is renowned for rapid and stable locomotion. We simultaneously recorded coxal levator and depressor motor neurons (MN in the thoracic ganglia of Periplaneta americana, while sensory feedback was completely blocked or allowed only from one intact stepping leg. In the absence of sensory feedback, we observed a coordination pattern with consistent phase relationship that shares similarities with a double tripod gait, suggesting central, feedforward control. This intersegmental coordination pattern was then reinforced in the presence of sensory feedback from a single stepping leg. Specifically, we report on transient stabilization of phase differences between activity recorded in the middle and hind thoracic MN following individual front-leg steps, suggesting a role for afferent phasic information in the coordination of motor circuits at the different hemiganglia. Data were further analyzed using stochastic models of coupled oscillators and maximum likelihood techniques to estimate underlying physiological parameters, such as uncoupled endogenous frequencies of hemisegmental oscillators and coupling strengths and directions. We found that descending ipsilateral coupling is stronger than ascending coupling, while left-right coupling in both the meso- and meta-thoracic ganglia appear to be symmetrical. We discuss our results in comparison with recent findings in stick insects that share similar neural and body architectures, and argue that the two species may exemplify opposite extremes of a fast-slow locomotion continuum, mediated through different intersegmental

  10. Symmetry-Breaking in a Rate Model for a Biped Locomotion Central Pattern Generator

    Directory of Open Access Journals (Sweden)

    Ian Stewart

    2014-01-01

    Full Text Available The timing patterns of animal gaits are produced by a network of spinal neurons called a Central Pattern Generator (CPG. Pinto and Golubitsky studied a four-node CPG for biped dynamics in which each leg is associated with one flexor node and one extensor node, with Ζ2 x Ζ2 symmetry. They used symmetric bifurcation theory to predict the existence of four primary gaits and seven secondary gaits. We use methods from symmetric bifurcation theory to investigate local bifurcation, both steady-state and Hopf, for their network architecture in a rate model. Rate models incorporate parameters corresponding to the strengths of connections in the CPG: positive for excitatory connections and negative for inhibitory ones. The three-dimensional space of connection strengths is partitioned into regions that correspond to the first local bifurcation from a fully symmetric equilibrium. The partition is polyhedral, and its symmetry group is that of a tetrahedron. It comprises two concentric tetrahedra, subdivided by various symmetry planes. The tetrahedral symmetry arises from the structure of the eigenvalues of the connection matrix, which is involved in, but not equal to, the Jacobian of the rate model at bifurcation points. Some of the results apply to rate equations on more general networks.

  11. A modeling approach on why simple central pattern generators are built of irregular neurons.

    Directory of Open Access Journals (Sweden)

    Marcelo Bussotti Reyes

    Full Text Available The crustacean pyloric Central Pattern Generator (CPG is a nervous circuit that endogenously provides periodic motor patterns. Even after about 40 years of intensive studies, the rhythm genesis is still not rigorously understood in this CPG, mainly because it is made of neurons with irregular intrinsic activity. Using mathematical models we addressed the question of using a network of irregularly behaving elements to generate periodic oscillations, and we show some advantages of using non-periodic neurons with intrinsic behavior in the transition from bursting to tonic spiking (as found in biological pyloric CPGs as building components. We studied two- and three-neuron model CPGs built either with Hindmarsh-Rose or with conductance-based Hodgkin-Huxley-like model neurons. By changing a model's parameter we could span the neuron's intrinsic dynamical behavior from slow periodic bursting to fast tonic spiking, passing through a transition where irregular bursting was observed. Two-neuron CPG, half center oscillator (HCO, was obtained for each intrinsic behavior of the neurons by coupling them with mutual symmetric synaptic inhibition. Most of these HCOs presented regular antiphasic bursting activity and the changes of the bursting frequencies was studied as a function of the inhibitory synaptic strength. Among all HCOs, those made of intrinsic irregular neurons presented a wider burst frequency range while keeping a reliable regular oscillatory (bursting behavior. HCOs of periodic neurons tended to be either hard to change their behavior with synaptic strength variations (slow periodic burster neurons or unable to perform a physiologically meaningful rhythm (fast tonic spiking neurons. Moreover, 3-neuron CPGs with connectivity and output similar to those of the pyloric CPG presented the same results.

  12. The Contribution of a Central Pattern Generator in a Reflex-Based Neuromuscular Model

    Directory of Open Access Journals (Sweden)

    Florin eDzeladini

    2014-06-01

    Full Text Available Although the concept of central pattern generators (CPGs controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s' demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented.The results highlight the advantages that a feedforward component can have in terms of gait modulation.

  13. Setting the pace: new insights into central pattern generator interactions in box jellyfish swimming.

    Directory of Open Access Journals (Sweden)

    Anna Lisa Stöckl

    Full Text Available Central Pattern Generators (CPGs produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians.

  14. Real-time biomimetic Central Pattern Generators into FPGA for hybrid experiments

    Directory of Open Access Journals (Sweden)

    Matthieu eAmbroise

    2013-11-01

    Full Text Available This article investigates the neural network system in the leech heartbeat and develops a real-time biomimetic digital hardware using few-resource implementation for hybrid experiments. The leech heartbeat neural network is one of the most simple central pattern generators (CPG. In biology, CPG provide for rhythmic bursts of spikes and is the basis for all muscles contractions orders (heartbeat and locomotion (walking, running….. The leech neural network system was already investigated and this CPG has been already formalized with Hodgkin-Huxley neural model (HH that is the most complex neuron model. However, the resources needed for a neural model is proportional to its complexity. To answer to this issue, this article describes a biomimetic implementation into FPGA (Field Programmable Gate Array of a network of 240 CPGs using a simple model (Izhikevich model and by proposing a new synapse model: activity dependent depression synapse. The architecture of the network implementation allows working on a single computation core. This digital system works in real-time, needs few resources and has the same bursting activity behavior than complex model. To validate our implementation of this CPG, we compare it firstly with a simulation of the complex model. Then we match its activity with the pharmacological data of the activity of the rat’s spinal cord. This digital system allows future hybrid experiments and will be a great step towards hybridation between biological tissue and artificial neural network. This network of CPG could be also useful for mimic the activity of a different animal locomotion or developing hybrid experiments for neuroprosthesis development.

  15. Setting the pace: new insights into central pattern generator interactions in box jellyfish swimming.

    Science.gov (United States)

    Stöckl, Anna Lisa; Petie, Ronald; Nilsson, Dan-Eric

    2011-01-01

    Central Pattern Generators (CPGs) produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora) with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs) considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians. PMID:22073288

  16. A Combination of Central Pattern Generator-based and Reflex-based Neural Networks for Dynamic, Adaptive, Robust Bipedal Locomotion

    DEFF Research Database (Denmark)

    Di Canio, Giuliano; Larsen, Jørgen Christian; Wörgötter, Florentin;

    2016-01-01

    the interaction of these systems, implementations with reflexbased or central pattern generator (CPG)-based controllers have been tested on bipedal robot systems. In this paper we will combine the two controller types, into a controller that works with both reflex and CPG signals. We use a reflex-based neural......Robotic systems inspired from humans have always been lightening up the curiosity of engineers and scientists. Of many challenges, human locomotion is a very difficult one where a number of different systems needs to interact in order to generate a correct and balanced pattern. To simulate...... network to generate basic walking patterns of a dynamic bipedal walking robot (DACBOT) and then a CPG-based neural network to ensure robust walking behavior...

  17. Integration of vision and central pattern generator based locomotion for path planning of a non-holonomic crawling humanoid robot

    OpenAIRE

    Gay, Sébastien; Dégallier Rochat, Sarah; Ijspeert, Auke; Santos-Victor, José

    2010-01-01

    In this paper we present our work on integrating a locomotion controller based on central pattern generator (CPG) and a motion planning algorithm using artificial potential fields for a non-holonomic crawling humanoid robot, the iCub. We also integrated a vision tracker and an inverse kinematics solver to perform reaching tasks. We study the influence of the various parameters of the potential field equations on the performance of the system and prove the efficiency of our framework by testin...

  18. Organisation of the spinal central pattern generators for locomotion in the salamander: biology and modelling.

    Science.gov (United States)

    Chevallier, Stéphanie; Jan Ijspeert, Auke; Ryczko, Dimitri; Nagy, Frédéric; Cabelguen, Jean-Marie

    2008-01-01

    Among living tetrapods, salamanders are regarded as most closely resembling the first terrestrial vertebrates, and are therefore an interesting group in which the evolutionary changes in the locomotor behaviour from aquatic to terrestrial habitats can be inferred. Salamanders exhibit two locomotor modes: swimming and terrestrial stepping. The swimming is anguilliform and resembles closely that of the lamprey. On the ground, the salamander switches to a stepping gait with axial undulations that is also observed in many reptiles. The salamander is therefore ideally suited for examining the neural mechanisms for the generation of these two locomotor modes, as well as the neural mechanisms of gait transition. In the present paper, we describe the kinematics and patterns of activation of axial and limb muscles during stepping and swimming in adult salamanders. We then review the current neurobiological data about the organisation of the spinal networks underlying swimming and stepping, and the mechanisms of gait transition. Finally we report modelling studies aimed at understanding the organisation and operation of the salamander locomotor circuits. Altogether, the neurobiological and the modelling data support the hypothesis of a phylogenetic conservatism from agnathians to amphibians of the spinal locomotor networks generating axial motor patterns.

  19. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution.

    Science.gov (United States)

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented.

  20. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution

    Science.gov (United States)

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I.; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

  1. Stable Walking of Humanoid Robots Using Vertical Center of Mass and Foot Motions by an Evolutionary Optimized Central Pattern Generator

    Directory of Open Access Journals (Sweden)

    Young-Dae Hong

    2016-02-01

    Full Text Available This paper proposes a method to produce the stable walking of humanoid robots by incorporating the vertical center of mass (COM and foot motions, which are generated by the evolutionary optimized central pattern generator (CPG, into the modifiable walking pattern generator (MWPG. The MWPG extends the conventional 3-D linear inverted pendulum model (3-D LIPM by allowing a zero moment point (ZMP variation. The disturbance caused by the vertical COM motion is compensated in real time by the sensory feedback in the CPG. In this paper, the vertical foot trajectory of the swinging leg, as well as the vertical COM trajectory of the 3-D LIPM, are generated by the CPG for the effective compensation of the disturbance. Consequently, using the proposed method, the humanoid robot is able to walk with a vertical COM and the foot motions generated by the CPG, while modifying its walking patterns by using the MWPG in real time. The CPG with the sensory feedback is optimized to obtain the desired output signals. The optimization of the CPG is formulated as a constrained optimization problem with equality constraints and is solved by two-phase evolutionary programming (TPEP. The validity of the proposed method is verified through walking experiments for the small-sized humanoid robot, HanSaRam-IX (HSR-IX.

  2. Modular organization of the multipartite central pattern generator for turtle rostral scratch: knee-related interneurons during deletions.

    Science.gov (United States)

    Stein, Paul S G; Daniels-McQueen, Susan; Lai, Jessica; Liu, Z; Corman, Tanya S

    2016-06-01

    Central pattern generators (CPGs) are neuronal networks in the spinal cord that generate rhythmic patterns of motor activity in the absence of movement-related sensory feedback. For many vertebrate rhythmic behaviors, CPGs generate normal patterns of motor neuron activities as well as variations of the normal patterns, termed deletions, in which bursts in one or more motor nerves are absent from one or more cycles of the rhythm. Prior work with hip-extensor deletions during turtle rostral scratch supports hypotheses of hip-extensor interneurons in a hip-extensor module and of hip-flexor interneurons in a hip-flexor module. We present here single-unit interneuronal recording data that support hypotheses of knee-extensor interneurons in a knee-extensor module and of knee-flexor interneurons in a knee-flexor module. Members of knee-related modules are not members of hip-related modules and vice versa. These results in turtle provide experimental support at the single-unit interneuronal level for the organizational concept that the rostral-scratch CPG for the turtle hindlimb is multipartite, that is, composed of more than two modules. This work, when combined with experimental and computational work in other vertebrates, does not support the classical view that the vertebrate limb CPG is bipartite with only two modules, one controlling all the flexors of the limb and the other controlling all the extensors of the limb. Instead, these results support the general principle that spinal CPGs are multipartite. PMID:27030737

  3. Preclinical evidence supporting the clinical development of central pattern generator-modulating therapies for chronic spinal cord-injured patients

    Directory of Open Access Journals (Sweden)

    Pierre eGuertin

    2014-05-01

    Full Text Available Ambulation or walking is one of the main gaits of locomotion. In terrestrial animals, it may be defined as a series of rhythmic and bilaterally coordinated movement of the limbs which creates a forward movement of the body. This applies regardless of the number of limbs - from arthropods with six or more limbs to bipedal primates. These fundamental similarities among species may explain why comparable neural systems and cellular properties have been found, thus far, to control in similar ways locomotor rhythm generation in most animal models. The aim of this article is to provide a comprehensive review of the known structural and functional features associated with central nervous system (CNS networks that are involved in the control of ambulation and other stereotyped motor patterns - specifically Central Pattern Generators (CPGs that produce basic rhythmic patterned outputs for locomotion, micturition, ejaculation, and defecation. Although there is compelling evidence of their existence in humans, CPGs have been most studied in reduced models including in vitro isolated preparations, genetically-engineered mice and spinal cord-transected animals. Compared with other structures of the CNS, the spinal cord is generally considered as being well-preserved phylogenetically. As such, most animal models of SCI should be considered as valuable tools for the development of novel pharmacological strategies aimed at modulating spinal activity and restoring corresponding functions in chronic spinal cord-injured patients.

  4. Monoaminergic and catecholaminergic activation of the central pattern generator for locomotion following spinal cord injury Innovative therapeutic approaches

    Institute of Scientific and Technical Information of China (English)

    Pierre A.Guertin

    2009-01-01

    The development of secondary health complications following spinal cord injury has been increasingly recognized by healthcare professionals as a major concern.These problems most specifically affect complete or near-complete spinal cord injury patients (e.g.,those with minimal mobility),who are not typically rehabilitated with treadmill training approaches,because motor control and leg movements are largely impaired.However,recent pharmaceutical advances in central pattern generator activation may provide new therapeutic hopes for these spinal cord injury patients.This article provides a comprehensive overview,for the non-specialist,of the most recent advances in this field.

  5. Central pattern generators for a common semiology in fronto-limbic seizures and in parasomnias. A neuroethologic approach.

    Science.gov (United States)

    Tassinari, C A; Rubboli, G; Gardella, E; Cantalupo, G; Calandra-Buonaura, G; Vedovello, M; Alessandria, M; Gandini, G; Cinotti, S; Zamponi, N; Meletti, S

    2005-12-01

    Central pattern generators (CPGs) are genetically determined neuronal aggregates in the mesencephalon, pons and spinal cord subserving innate motor behaviours essential for survival (feeding, locomotion, reproduction etc.). In higher primates CPGs are largely under neocortical control. We describe how certain motor events observed in parasomnias and epileptic seizures could have similar features and resemble motor behaviours, which can be the expression of the same CPG. Both epilepsy and sleep can lead to a temporary loss of control of neomammalian cortex that facilitates through a common platform (arousal) the emergences of stereotyped inborn fixed action patterns. Therefore we suggest that, independently from the nature of the trigger, be it a seizure or a parasomnia, the same CPGs can be involved, "caught up", leading to a common motor semiology (the "Carillon theory"). PMID:16331401

  6. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution

    Directory of Open Access Journals (Sweden)

    Andrés Espinal

    2016-07-01

    Full Text Available This paper deals with the design of Spiking Central Pattern Generators (SCPGs to achieve locomotion at different frequencies in legged robots and their hardware implementation in a FPGA and validation on a real hexapod robot. Herein, the SCPGs are automatically designed by a Christiansen Grammar Evolution (CGE-based methodology. It is, the CGE performs a solution for the configurations (synaptic weights and connections of each neuron in the SCPG. This is carried out through the indirect representation of a candidate solution that evolves to replicate a specific spike train according to a locomotion pattern (gait by measuring the similarity between the spike train with the SPIKE-Distance to drive the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the fitness function to achieve the SPIKE-distance criteria, such as: looking for SNNs with minimal connectivity or a CPG able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 DOFs hexapod robot is presented.

  7. Exercise, music, and the brain: is there a central pattern generator?

    Science.gov (United States)

    Schneider, Stefan; Askew, Christopher D; Abel, Thomas; Strüder, Heiko K

    2010-10-01

    The frequency for movements along the longitudinal axis during running peaks at approximately 3 Hz. Other physiological systems (e.g. heart rate and brain cortical activity) are known to show a dominant frequency of ~3 Hz connected to exercise. As recent studies have proposed a clear correlation between musical tempo, mood, and performance output, we wished to ascertain whether peak locomotion frequency of ~3 Hz during running is synchronized with different intrinsic and extrinsic frequencies. Eighteen healthy regular runners performed three outdoor running sessions at different intensities. Oscillations along the longitudinal axis were recorded using an accelerometer (ActiBelt). Electrocortical activity was recorded using electroencephalography before and after exercise and analysed in the delta frequency range (2-4 Hz). In addition, the frequency spectra of the participants' favourite musical pieces were analysed. Data revealed a peak frequency at around 2.7 to 2.8 Hz for the vertical acceleration during running. Similar oscillation patterns were found for heart rate and musical pieces. Electroencephalographic delta activity increased after running. Results of this study give reason to speculate that a strong relationship exists between intrinsic and extrinsic oscillation patterns during exercise. A frequency of approximately 3 Hz seems to be dominant in different physiological systems and seems to be rated as pleasurable when choosing the appropriate music for exercising. This is in line with previous research showing that an adequate choice of music during exercise enhances performance output and mood.

  8. Multiple Chaotic Central Pattern Generators with Learning for Legged Locomotion and Malfunction Compensation

    DEFF Research Database (Denmark)

    Ren, Guanjiao; Chen, Weihai; Dasgupta, Sakyasingha;

    2015-01-01

    on a simulated annealing algorithm. In a normal situation, the CPGs synchronize and their dynamics are identical. With leg malfunction or disability, the CPGs lose synchronization leading to independent dynamics. In this case, the learning mechanism is applied to automatically adjust the remaining legs...... in a physical simulation of a quadruped as well as a hexapod robot and finally in a real six-legged walking machine called AMOSII. The experimental results presented here reveal that using multiple CPGs with learning is an effective approach for adaptive locomotion generation where, for instance, different body...... chaotic CPG controller has difficulties dealing with leg malfunction. Specifically, in the scenarios presented here, its movement permanently deviates from the desired trajectory. To address this problem, we extend the single chaotic CPG to multiple CPGs with learning. The learning mechanism is based...

  9. Evolution of central pattern generators for the control of a five-link planar bipedal walking mechanism

    CERN Document Server

    Baydin, Atilim Gunes

    2008-01-01

    With the aim of producing a stable human-like bipedal gait, a five-link planar walking mechanism was coupled with a central pattern generator (CPG) network, consisting of units based on Matsuoka's half-center oscillator model. As a minimalistic approach to bipedal walking, this type of walking mechanism contains only four actuators (two in the hip joints and two in the knee joints), and is lacking feet and ankles. Firstly, the mechanism was designed and built as a physical simulation programmed from scratch, providing a platform for hand-tuned tests and the creation of a CPG controller by genetic algorithms (GA). The oscillatory characteristics of the CPG network together with its internal connection structure and the feedback pathways from the environment were subject to GA optimization. The approach proved successful and the results were then transferred to a hardware realization of the five-link walking mechanism, to test how well these perform under real-world dynamics. Results suggest that the biological...

  10. A novel approach to locomotion learning: Actor-Critic architecture using central pattern generators and dynamic motor primitives.

    Science.gov (United States)

    Li, Cai; Lowe, Robert; Ziemke, Tom

    2014-01-01

    In this article, we propose an architecture of a bio-inspired controller that addresses the problem of learning different locomotion gaits for different robot morphologies. The modeling objective is split into two: baseline motion modeling and dynamics adaptation. Baseline motion modeling aims to achieve fundamental functions of a certain type of locomotion and dynamics adaptation provides a "reshaping" function for adapting the baseline motion to desired motion. Based on this assumption, a three-layer architecture is developed using central pattern generators (CPGs, a bio-inspired locomotor center for the baseline motion) and dynamic motor primitives (DMPs, a model with universal "reshaping" functions). In this article, we use this architecture with the actor-critic algorithms for finding a good "reshaping" function. In order to demonstrate the learning power of the actor-critic based architecture, we tested it on two experiments: (1) learning to crawl on a humanoid and, (2) learning to gallop on a puppy robot. Two types of actor-critic algorithms (policy search and policy gradient) are compared in order to evaluate the advantages and disadvantages of different actor-critic based learning algorithms for different morphologies. Finally, based on the analysis of the experimental results, a generic view/architecture for locomotion learning is discussed in the conclusion. PMID:25324773

  11. A Novel Approach to Locomotion Learning: Actor-Critic Architecture using Central Pattern Generators and Dynamic Motor Primitives

    Directory of Open Access Journals (Sweden)

    Cai eLi

    2014-10-01

    Full Text Available In this article, we propose an architecture of a bio-inspired controller that addresses the problem of learning different locomotion gaits for different robot morphologies. The modelling objective is split into two: baseline motion modelling and dynamics adaptation. Baseline motion modelling aims to achieve fundamental functions of a certain type of locomotion and dynamics adaptation provides a ``reshaping function for adapting the baseline motion to desired motion. Based on this assumption, a three-layer architecture is developed using central pattern generators (CPGs, a bio-inspired locomotor center for the the baseline motion and dynamic motor primitives (DMPs, a model with universal ``reshaping functions. In this article, we use this architecture with the actor-critic algorithms for finding a good ``reshaping function. In order to demonstrate the learning power of the actor-critic based architecture, we tested it on two experiments: 1 learning to crawl on a humanoid and, 2 learning to gallop on a puppy robot. Two types of actor-critic algorithms (policy search and policy gradient are compared in order to evaluate the advantages and disadvantages of different actor-critic based learning algorithms for different morphologies. Finally, based on the analysis of the experimental results, a generic view/architecture for locomotion learning is discussed in the conclusion.

  12. Simulation Platform of Underwater Quadruped Walking Robot Based on MotionGenesis Kane 5 3 and Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    Ke Yang; XuYang Wang; Tong Ge; Chao Wu

    2014-01-01

    It will still in lack of a simulation platform used to learn the walking of underwater quadruped walking robot. In order to alleviate this shortage, a simulation platform for the underwater quadruped walking robot based on Kane dynamic model and CPG-based controller is constructed. The Kane dynamic model of the underwater quadruped walking robot is processed with a commercial package MotionGenesis Kane 5�3. The forces between the feet and ground are represented as a spring and damper. The relation between coefficients of spring and damper and stability of underwater quadruped walking robot in the stationary state is studied. The CPG-based controller consisted of Central Pattern Generator ( CPG) and PD controller is presented, which can be used to control walking of the underwater quadruped walking robot. The relation between CPG parameters and walking speed of underwater quadruped walking robot is investigated. The relation between coefficients of spring and damper and walking speed of underwater quadruped walking robot is studied. The results show that the simulation platform can imitate the stable walking of the underwater quadruped walking robot.

  13. GENERATING DISCOURSE THROUGH PATTERNS

    Directory of Open Access Journals (Sweden)

    Gina Necula

    2006-05-01

    Full Text Available When trying to analyse the ways of generating a discourse, one can easily understand that this process presupposes a collage of already made linguistic structures likely to be decoded by speakers under certain conditions such as: sharing the same code, assigning the same meaning to the structure in case, etc. Linguistic patterns are condensed formulas communicating universal wisdom whose occurrence in the discourse confers argumentative authority. Originating in former or present lingua franca and being widely recognized, such structures have inroaded into other languages, preserving the same strategic use in view of reaching persuasive goals.

  14. In vivo modulation of interacting central pattern generators in lobster stomatogastric ganglion: influence of feeding and partial pressure of oxygen.

    Science.gov (United States)

    Clemens, S; Massabuau, J C; Legeay, A; Meyrand, P; Simmers, J

    1998-04-01

    The stomatogastric ganglion (STG) of the European lobster Homarus gammarus contains two rhythm-generating networks (the gastric and pyloric circuits) that in resting, unfed animals produce two distinct, yet strongly interacting, motor patterns. By using simultaneous EMG recordings from the gastric and pyloric muscles in vivo, we found that after feeding, the gastropyloric interaction disappears as the two networks express accelerated motor rhythms. The return to control levels of network activity occurs progressively over the following 1-2 d and is associated with a gradual reappearance of the gastropyloric interaction. In parallel with this change in network activity is an alteration of oxygen levels in the blood. In resting, unfed animals, arterial partial pressure of oxygen (PO2) is most often between 1 and 2 kPa and then doubles within 1 hr after feeding, before returning to control values some 24 hr later. In vivo, experimental prevention of the arterial PO2 increase after feeding leads to a slowing of pyloric rhythmicity toward control values and a reappearance of the gastropyloric interaction, without apparent effect on gastric network operation. Using in vitro preparations of the stomatogastric nervous system and by changing oxygen levels uniquely at the level of the STG within the range observed in the intact animal, we were able to mimic most of the effects observed in vivo. Our data indicate that the gastropyloric interaction appears only during a "free run" mode of foregut activity and that the coordinated operation of multiple neural networks may be modulated by local changes in oxygenation. PMID:9502835

  15. 基于中枢模式发生器的机器人行走控制%Locomotion Control of Quadruped Robot Based on Central Pattern Generators

    Institute of Scientific and Technical Information of China (English)

    陈启军; 王国星; 刘成菊

    2010-01-01

    基于中枢模式发生器(central pattern generator,CPG)的动物运动控制机理实现四足机器人AIBO的行走控制.利用Kimura振荡神经元构建CPG分布式控制网络,通过多目标遗传算法优化调整CPG网络中的参数,在AIBO上实现类似动物行走(walk)的行走模式.通过Webots仿真和实体实验,验证所设计的CPG控制网络和控制方法的可行性与有效性.

  16. 基于中枢模式发生器的仿人机器人步态规划%Humanoid robot gait planning based on Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    李正文; 张国良; 张维平; 羊帆

    2011-01-01

    对Matsuoka振荡器进行了分析,根据仿人机器人步态规划的要求,选用Matsuoka振荡器构建了中枢模式发生器(CPG)网络;采用遗传算法(GA)来调整网络的参数,解决了关键的网络参数调整的问题;根据CPG网络的输出结果,控制仿人机器人的相应关节,实现了仿人机器人基本步态规划。通过ADAMS进行了仿真,结果表明,该控制策略具有较理想的效果,并且原理简单,易于实现。%The Matsuoka oscillator was analyzed, according to the humanoid robot gait planning requirements, the Matsuoka oscillator was selected to construct the Central Pattern Generator (CPG) network, using genetic algorithms (GA) to adjust the network parameters, the key network parameter adjustment problem was solved; according to the CPG network output results, the humanoid robot relevant joint was controlled, the basic gait planning of the humanoid robot was achieved. Through the ADAMS simulation, the results show that this control strategy has an ideal effect, and the principle is simple, easy to implement.

  17. 基于中枢神经模式的四足机器人步态控制%Quadruped Robot Gait Control Based on Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    黄博; 姚玉峰; 孙立宁

    2010-01-01

    为实现四足机器人稳定的节律性行走,研究基于中枢神经模式发生器(Central pattern generator, CPG)的比例步态控制方式.构建互抑神经元组成的振荡器模型,并基于振荡器模型组建四足机器人髋关节CPG网络.通过仿真研究得到模型各参数与CPG网络输出特性之间的关系,确定一套整定后CPG网络的模型参数,提出四足机器人比例步态,通过CPG模型阈值的调整可实现不同占空比的步态.对基于CPG网络的步态反射特性进行分析.试验表明,该方法可实现稳定的四足机器人行走,且具备一定的障碍物反射能力,具有较好的环境适应性.

  18. 基于生物中枢模式发生器原理的四足机器人%Quadruped robot based on biological central pattern generator

    Institute of Scientific and Technical Information of China (English)

    郑浩峻; 张秀丽; 关旭; 汪劲松

    2004-01-01

    传统由人工规划产生的步态是比较僵硬的、缓慢的,缺乏灵活的自组织能力,与真正的动物步态存在很大差别.该文提出了机器人生物步态的概念.以生物的中枢模式发生器(central pattern generator, CPG)模型为核心建立四足机器人运动控制系统,建立CPG网络的权重矩阵与步态的对应关系.采用不同的权重矩阵得到四足机器人的典型步态.根据哺乳动物的肢体运动关系,建立机器人膝髋关节运动关系方程.通过仿真验证了基于生物CPG控制机理的机器人节律运动控制方法是有效的,机器人生物步态的实现是可能的.

  19. Generation Y Online Buying Patterns

    Directory of Open Access Journals (Sweden)

    Katija Vojvodić

    2015-12-01

    Full Text Available The advantages of electronic retailing can, among other things, result in uncontrolled buying by online consumers, i.e. in extreme buying behavior. The main purpose of this paper is to analyze and determine the buying patterns of Generation Y online consumers in order to explore the existence of different types of behavior based on the characteristics of online buying. The paper also aims at exploring the relationship between extracted factors and Generation Y consumers’ buying intentions. Empirical research was conducted on a sample of 515 consumers in the Dubrovnik-Neretva County. Based on the factor analysis, research results indicate that Generation Y online consumers are influenced by three factors: compulsivity, impulsivity, and functionality. The analysis of variance reveals that significant differences exist between the extracted factors and Generation Y’s online buying characteristics. In addition, correlation analysis shows a statistically significant correlation between the extracted factors and Generation Y’s buying intentions.

  20. Long-term maintenance of channel distribution in a central pattern generator neuron by neuromodulatory inputs revealed by decentralization in organ culture.

    Science.gov (United States)

    Mizrahi, A; Dickinson, P S; Kloppenburg, P; Fénelon, V; Baro, D J; Harris-Warrick, R M; Meyrand, P; Simmers, J

    2001-09-15

    Organotypic cultures of the lobster (Homarus gammarus) stomatogastric nervous system (STNS) were used to assess changes in membrane properties of neurons of the pyloric motor pattern-generating network in the long-term absence of neuromodulatory inputs to the stomatogastric ganglion (STG). Specifically, we investigated decentralization-induced changes in the distribution and density of the transient outward current, I(A), which is encoded within the STG by the shal gene and plays an important role in shaping rhythmic bursting of pyloric neurons. Using an antibody against lobster shal K(+) channels, we found shal immunoreactivity in the membranes of neuritic processes, but not somata, of STG neurons in 5 d cultured STNS with intact modulatory inputs. However, in 5 d decentralized STG, shal immunoreactivity was still seen in primary neurites but was likewise present in a subset of STG somata. Among the neurons displaying this altered shal localization was the pyloric dilator (PD) neuron, which remained rhythmically active in 5 d decentralized STG. Two-electrode voltage clamp was used to compare I(A) in synaptically isolated PD neurons in long-term decentralized STG and nondecentralized controls. Although the voltage dependence and kinetics of I(A) changed little with decentralization, the maximal conductance of I(A) in PD neurons increased by 43.4%. This increase was consistent with the decentralization-induced increase in shal protein expression, indicating an alteration in the density and distribution of functional A-channels. Our results suggest that, in addition to the short-term regulation of network function, modulatory inputs may also play a role, either directly or indirectly, in controlling channel number and distribution, thereby maintaining the biophysical character of neuronal targets on a long-term basis. PMID:11549743

  1. Generation of central exclusive final states

    CERN Document Server

    Lönnblad, Leif

    2016-01-01

    We present a scheme for the generation of central exclusive final states in the Pythia 8 program. The implementation allows for the investigation of higher order corrections to such exclusive processes as approximated by the initial-state parton shower in Pythia 8. To achieve this, the spin and colour decomposition of the initial-state shower has been worked out, in order to determine the probability that a partonic state generated from an inclusive sub-process followed by a series of initial-state parton splittings can be considered as an approximation of an exclusive colour- and spin-singlet process. We use our implementation to investigate effects of parton showers on some examples of central exclusive processes, and find sizeable effects on di-jet production, while the effects on e.g. central exclusive Higgs production are minor.

  2. Airflow Pattern Generated by Three Air Diffusers

    DEFF Research Database (Denmark)

    Olmedo, Inés; Nielsen, Peter V.; Ruiz de Adana, Manuel;

    2011-01-01

    The correct description of air diffusers plays a crucial role in the CFD predictions of the airflow pattern into a room. The numerical simulation of air distribution in an indoor space is challenging because of the complicated airflow pattern generated. Many authors have developed simplified geom...

  3. Second-generation central receiver technology comparison

    Science.gov (United States)

    Klimas, P. C.; Becker, M.

    Fifteen years of solar thermal technology development have produced a considerable amount of knowledge relating to the production of electricity from central receiver power plants. This body of knowledge is under examination by researchers from the United States and the Federal Republic of Germany for the purpose of defining the next generation central receiver electricity producers. This second generation power plant is expected to represent a significant step towards commercialization of these systems. During the course of the study, specific activities needed to realize this next-step technology are being defined. The study is an international team effort. Under the International Energy Agency Small Solar Power Systems project, researchers from DLR, Interatom, Sandia National Laboratories, and Bechtel have designed a study in which technologies relating to existing systems are quantified, logical next-step systems are characterized, and future potential advances are identified. The receiver concepts under investigation are: salt-in-tube, volumetric, and direct absorption. Two plant performance levels are examined, 30 and 100 MW(sub e). Each concept is applied with common capacity factors, solar multiples, and types and sizes of heliostats at each performance level. Availability and uncertainty analyses are also performed. Annual energy production figures are calculated using the SOLERGY computer code. Capital and Operation and Maintenance cost methodologies are mutually agreed upon in order that levelized energy cost calculations will be consistent for each power plant. During the course of this effort, further potential advances in central receiver technology have continued to become apparent. These possible areas for improvement will be described. An additional comparison is being made between central receivers and trough-based systems.

  4. Legume Diversity Patterns in West Central Africa

    NARCIS (Netherlands)

    Estrella, de la M.; Mateo, M.A.; Wieringa, J.J.; Mackinder, B.; Munoz, J.

    2012-01-01

    Objectives - Species Distribution Models (SDMs) are used to produce predictions of potential Leguminosae diversity in West Central Africa. Those predictions are evaluated subsequently using expert opinion. The established methodology of combining all SDMs is refined to assess species diversity withi

  5. EXPLAINING TRAFFIC FLOW PATTERNS USING CENTRALITY MEASURES

    Directory of Open Access Journals (Sweden)

    Amila Jayasinghe

    2015-06-01

    Full Text Available This study examines the capability of centrality parameters of the road network to explain and predict traffic flow by types of vehicles. The case study was conducted in Colombo Metropolitan Area, Sri Lanka. Study used four centrality parameters i.e. connectivity, global integration, local integration and choice; and three analysis methods i.e. topological, metric and angular which introduced by space syntax analysis method to compute network centrality of the road network. Findings of this study stress that, (1 human beings perceive the space mostly from geometrical distance (topological and angular distance in comparison to metric distance. Further to this, it was found that angular distance is more powerful in global level whereas topological distance is more powerful in local level; (2 it is more appropriate to consider the multiple influences from multiple centrality parameters rather being confined to a single best parameter and influence of each parameter varies based on type of vehicles.

  6. Generating a Pattern Matching Compiler by Partial Evaluation

    DEFF Research Database (Denmark)

    Jørgensen, Knud Jesper

    1991-01-01

    Datalogi, partial Evaluation, Compiling, denotational Semantics, Pattern Matching, Semantic directed Compiler Generation......Datalogi, partial Evaluation, Compiling, denotational Semantics, Pattern Matching, Semantic directed Compiler Generation...

  7. The effect of gait Central pattern generators on walking function of stroke patients%步态中枢模式发生器对脑卒中偏瘫患者步行能力的影响

    Institute of Scientific and Technical Information of China (English)

    王文威; 潘翠环; 陈艳; 罗兆良; 罗丽娟

    2011-01-01

    Objective:To explore the effect of gait central pattern generators on walking function of stroke patients.Method: Eighty stroke patients were randomly assigned to the treatment group (observation group, 40 cases) and the control group (40 cases).AII the patients were treated with rehabilitation training. In addition, observation group adopted the activation of gait central pattern generators(CPG) training. The total course of 2 groups were 1month.Patients were assessed with lower extremity Fugl-Meyer motor function scale(FMA), modified Ashworth scale (MAS), Holden walking function rating scale (FAC) before and after rehabilitation treatment.At the same time, footprint analysis was used to measure and record the time and distance parameters of walking. The improvement of gait was analysed.Result: Compared to before, after the activation of gait CPG training, there were significant differences of FMA,FAC scores(P<0.05), there were different degrees of improvement in time and distance parameters of walking(P<0.05).Conclusion:The activation of gait CPG training can raise the lower extremity motor function as well as the practical walking ability, and improve the walking gait of stroke patients.%目的:探讨步态中枢模式发生器对脑卒中偏瘫患者步行能力的影响.方法:将80例脑卒中偏瘫患者随机分为治疗组(观察组)40例和对照组40例,两组患者均采用常规康复方法进行治疗,观察组还另外采用激活步态中枢模式发生器(CPG)的运动训练方法.两组患者总疗程均为1个月.分别在康复治疗前后采用Fugl-Meyer下肢运动功能量表(FMA)、改良Ashworth量表(MAS)、Holden步行功能分级量表(FAC)进行评定,同时选用足印分析法测量并记录步行时的时间距离参数的变化,分析步态的改善情况.结果:患者经过激活步态CPG的运动训练方法训练后,其FMA、FAC评分与治疗前相比差异有显著性意义(P<0.05),步行时间距离各参数也

  8. 基于CPG的双足机器人多层步行控制器设计%Central pattern generator based multi-level walking controller design of biped robot

    Institute of Scientific and Technical Information of China (English)

    薛方正; 陈强; 厚之成

    2015-01-01

    For walking controller design of the biped robot, a walking controller with multi-level structure is proposed by integrating the central pattern generator(CPG) stability analysis from the perspective of biological inspiration. The walking model of the biped robot is given. Then, the multi-level structure walking controller is proposed. By using the limit cycle theory, the walking stability is analyzed systematically. Compared with existing methods, the propoed controller is superior in simple structure, good versatility and converient online smoothing correction on the premise of walking stability. The simulation results show the effectiveness of proposed method.%针对双足机器人步行控制器的设计问题,基于生物学启发原理,提出一种基于中枢模式发生器(CPG)与稳定性分析相结合的多层次结构控制器设计方法。分析机器人的步行运动,给出双足运动描述。基于CPG理论设计多层次结构的步行控制器,应用极限环理论方法分析运动稳定性。在保证步行稳定的前提下,所提出的控制方法具有结构简单、通用性好、方便在线平滑修正等优点,步行仿真实验验证了所提出算法的有效性。

  9. Synaptic vesicle generation from central nerve terminal endosomes.

    Science.gov (United States)

    Kokotos, Alexandros C; Cousin, Michael A

    2015-03-01

    Central nerve terminals contain a small number of synaptic vesicles (SVs) that must sustain the fidelity of neurotransmission across a wide range of stimulation intensities. For this to be achieved, nerve terminals integrate a number of complementary endocytosis modes whose activation spans the breadth of these neuronal stimulation patterns. Two such modes are ultrafast endocytosis and activity-dependent bulk endocytosis, which are triggered by stimuli at either end of the physiological range. Both endocytosis modes generate endosomes directly from the nerve terminal plasma membrane, before the subsequent production of SVs from these structures. This review will discuss the current knowledge relating to the molecular mechanisms involved in the generation of SVs from nerve terminal endosomes, how this relates to other mechanisms of SV production and the functional role of such SVs.

  10. 基于中枢模式产生器的主动式智能踝关节控制的研究%Study on the Control of Dynamic Artificial Limb Ankle Based on Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    郭欣; 徐彩玉; 李明月; 苏龙涛

    2014-01-01

    In order to obtain the normal gait for the prosthesis-carrier with the change of external environment and gait,we designed a model of dynamic ankle prosthesis and control system and introduced the strategy of central pattern generator (CPG) about the moving trail of dynamic ankle prosthesis.The dynamic parts,which are incorporated in the model of dynamic ankle prosthesis,provide power in order to have anthropic function and character.The tool of Matlab/simulink was used to simulate the strategy.The simulation results showed that the strategy of CPG learning control in this study was effective and could track the reference trail rapidly and fit the moving trail of a person's normal limb.It can make the prosthetic timely regulation and action,enhance the prosthetic intelligence.It has important practical value for intelligent prosthesis development based on this analysis of technology.%为了使主动式踝关节假肢携带者能更好地根据外部环境和步态的变化实现假肢自然行走,设计了主动式智能踝关节假肢的机械结构和控制系统,提出了主动式踝关节假肢运动轨迹的中枢模式产生器(CPG)控制策略.主动式踝关节假肢通过动力机构为人体提供了运动动力,可实现人体运动的主要功能和特性.通过Matlab/simulink仿真,有效验证了基于生物中枢模式产生器控制机制的主动式踝关节的运动控制方法,能够使主动式踝关节假肢的输出轨迹准确快速地跟踪期望轨迹.因此该主动式踝关节假肢能实现及时调节和动作,智能性增强,同时本文提出的该项技术对智能假肢的发展具有重要的实用价值.

  11. Centrally patterned rhythmic activity integrated by a peripheral circuit linking multiple oscillators.

    Science.gov (United States)

    Jellies, John; Kueh, Daniel

    2012-08-01

    The central pattern generator for heartbeat in the medicinal leech, Hirudo generates rhythmic activity conveyed by heart excitor motor neurons in segments 3-18 to coordinate the bilateral tubular hearts and side vessels. We focus on behavior and the influence of previously un-described peripheral nerve circuitry. Extracellular recordings from the valve junction (VJ) where afferent vessels join the heart tube were combined with optical recording of contractions. Action potential bursts at VJs occurred in advance of heart tube and afferent vessel contractions. Transections of nerves were performed to reduce the output of the central pattern generator reaching the heart tube. Muscle contractions persisted but with a less regular rhythm despite normal central pattern generator rhythmicity. With no connections between the central pattern generator and heart tube, a much slower rhythm became manifest. Heart excitor neuron recordings showed that peripheral activity might contribute to the disruption of centrally entrained contractions. In the model presented, peripheral activity would normally modify the activity actually reaching the muscle. We also propose that the fundamental efferent unit is not a single heart excitor neuron, but rather is a functionally defined unit of about three adjacent motor neurons and the peripheral assembly of coupled peripheral oscillators.

  12. Enhancing SAT-Based Test Pattern Generation

    Institute of Scientific and Technical Information of China (English)

    LIU Xin; XIONG You-lun

    2005-01-01

    This paper presents modeling tools based on Boolean satisfiability (SAT) to solve problems of test generation for combinational circuits. It exploits an added layer to maintain circuit-related information and value justification relations to a generic SAT algorithm. It dovetails binary decision graphs (BDD) and SAT techniques to improve the efficiency of automatic test pattern generation (ATPG). More specifically, it first exploits inexpensive reconvergent fanout analysis of circuit to gather information on the local signal correlation by using BDD learning, then uses the above learned information to restrict and focus the overall search space of SAT-based ATPG. Its learning technique is effective and lightweight. The experimental results demonstrate the effectiveness of the approach.

  13. Patterning techniques for next generation IC's

    Science.gov (United States)

    Balasinski, A.

    2007-12-01

    Reduction of linear critical dimensions (CDs) beyond 45 nm would require significant increase of the complexity of pattern definition process. In this work, we discuss the key successor methodology to the current optical lithography, the Double Patterning Technique (DPT). We compare the complexity of CAD solutions, fab equipment, and wafer processing with its competitors, such as the nanoimprint (NIL) and the extreme UV (EUV) techniques. We also look ahead to the market availability for the product families enabled using the novel patterning solutions. DPT is often recognized as the most viable next generation lithography as it utilizes the existing equipment and processes and is considered a stop-gap solution before the advanced NIL or EUV equipment is developed. Using design for manufacturability (DfM) rules, DPT can drive the k1 factor down to 0.13. However, it faces a variety of challenges, from new mask overlay strategies, to layout pattern split, novel OPC, increased CD tolerances, new etch techniques, as well as long processing time, all of which compromise its return on investment (RoI). In contrast, it can be claimed e.g., that the RoI is the highest for the NIL but this technology bears significant risk. For all novel patterning techniques, the key questions remain: when and how should they be introduced, what is their long-term potential, when should they be replaced, and by what successor technology. We summarize the unpublished results of several panel discussions on DPT at the recent SPIE/BACUS conferences.

  14. Automatic Test Pattern Generation for Digital Circuits

    Directory of Open Access Journals (Sweden)

    S. Hemalatha

    2014-04-01

    Full Text Available Digital circuits complexity and density are increasing and at the same time it should have more quality and reliability. It leads with high test costs and makes the validation more complex. The main aim is to develop a complete behavioral fault simulation and automatic test pattern generation (ATPG system for digital circuits modeled in verilog and VHDL. An integrated Automatic Test Generation (ATG and Automatic Test Executing/Equipment (ATE system for complex boards is developed here. An approach to use memristors (resistors with memory in programmable analog circuits. The Main idea consists in a circuit design in which low voltages are applied to memristors during their operation as analog circuit elements and high voltages are used to program the memristor’s states. This way, as it was demonstrated in recent experiments, the state of memristors does not essentially change during analog mode operation. As an example of our approach, we have built several programmable analog circuits demonstrating memristor -based programming of threshold, gain and frequency. In these circuits the role of memristor is played by a memristor emulator developed by us. A multiplexer is developed to generate a class of minimum transition sequences. The entire hardware is realized as digital logical circuits and the test results are simulated in Model sim software. The results of this research show that behavioral fault simulation will remain as a highly attractive alternative for the future generation of VLSI and system-on-chips (SoC.

  15. The central government power generating capacity- reforms and the future

    International Nuclear Information System (INIS)

    The alarming resource gap that the states were facing in 1970's has prompted the Central Government to augment the resources for power generation by creating two new entities in November 1975 viz the National Thermal Power Corporation (NTPC) and National Hydro Power Corporation (NHPC). Few other organisations also exist in central sector which are engaged in power generation like Nuclear Power Corporation (NPC). NTPC being the leading player in the power sector, it can neither be indifferent nor dissociate itself from the reforms sweeping the sector today. The article describes the Central Government's role in power generation, reforms and NTPC and further prospects of NTPC

  16. On the generation of coastal lows in central Chile

    International Nuclear Information System (INIS)

    Previous studies of the coastal-low occurrences in central Chile have been aimed at the formulation of a conceptual model to explain observed features in connection with applied studies. The most prominent weather pattern associated with CL occurrences, (type A), coincides with the onset of a warm, middle-troposphere ridge over central Chile, and a surface high over northern Argentina. The synoptic forcing of the low is related to weak frontal disturbances that travel equatorwards. They result in a thickening of the marine layer that becomes blocked by the coastal escarpment, at the time of the onset of the ridge aloft. The blocking of the stable air above the subsidence inversion by the Andes is also hypothesized. The analysis of the subsidence inversion, the geometry of the coastal and Andes mountain ranges, and a scale analysis of the non-dimensional governing equations for the generation of the coastal lows, following the approach of Reason and Steyn (1990); leads to the conclusion that both blocking actions are strong and persistent in central Chile. An interactive mechanism between the upper and lower blocking effects is postulated to explain the cyclonic vorticity and the initial steering of the coastal lows. The scale analysis of the governing equations for the propagation stage of the low suggests that, departing for the South African case, non-linearity is important here, and that solitary Kelvin waves could be expected. Theoretical phase propagation speeds and Rossby radii are found to range between 8 and 15 m s-1 and 100-250 km, respectively. The importance of strong southerly winds ahead of the low and weak winds at its trailing edge is also stressed, as another major departure from the coastal-low behaviour elsewhere. (author). 17 refs, 4 figs, 4 tabs

  17. 基于中枢神经模式产生器机器人的控制网络%Control Network for Humanoid Robots Based on Central Pattern Generator

    Institute of Scientific and Technical Information of China (English)

    于小翔

    2011-01-01

    分析了基于中枢神经模式产生器(Ccntral Pattern Generator,CPG)的仿人机器人控制网络系统结构的特点,介绍了振荡器的数学模型.研究了CPG网络中各神经元的刺激方式,采用Hopf非线性振荡器构造神经元,模仿人类的行走步态,设计一种6关节控制网络.计算仿真中该网络输出信号稳定,运动节奏符合设计要求.最后,应用一仿人机器人完成了实验,提高了其行走的速度和稳定性,验证了该网络的有效性.

  18. Generating IDS Attack Pattern Automatically Based on Attack Tree

    Institute of Scientific and Technical Information of China (English)

    向尕; 曹元大

    2003-01-01

    Generating attack pattern automatically based on attack tree is studied. The extending definition of attack tree is proposed. And the algorithm of generating attack tree is presented. The method of generating attack pattern automatically based on attack tree is shown, which is tested by concrete attack instances. The results show that the algorithm is effective and efficient. In doing so, the efficiency of generating attack pattern is improved and the attack trees can be reused.

  19. Generation 1.5 Written Error Patterns: A Comparative Study

    Science.gov (United States)

    Doolan, Stephen M.; Miller, Donald

    2012-01-01

    In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student…

  20. Pattern Generation by Bubble Packing Method

    Directory of Open Access Journals (Sweden)

    Goel V.K.

    2013-06-01

    Full Text Available This paper presents a new computational method forornamental Pattern design. The work is a concerted effort ofevaluation of various methods and the comparatively betterprocess is used for designing keeping in mind the accuracyrequirement for such Indian traditional ethnic designs. The firststep in the process to apply the CAD tools to design the patterns.Small semantics (profile are made using the mathematicalmodelling to make different pattern. Geometric constraints suchas scaling, rotation, transformation etc. are applied to make andmodify the profiles. To create patterns, obtains node locationsthrough a physically based particle simulation, which we call'bubble packing. Bubbles are closely packed on the corners,edges and on the surface domain, and nodes are placed at thecenters of the bubbles. Experimental results show that ourmethod can create high quality ornamental patterns. Thefabrication of the ornaments is on rapid prototype machine.

  1. Schooling Experiences of Central California Indian People across Generations

    Science.gov (United States)

    Williams, Tara

    2012-01-01

    This exploratory study took a post-colonialist lens to record, examine and document schooling experiences of California Indian people across several generations representing three Central Valley tribes: the Mono, the Tachi Yokuts of Santa Rosa Rancheria, and the Tule River Tribe. Past and present perceptions of Indian schooling were elicited…

  2. Pattern Visualization Through Detection Plane Generation for Macroscopic Imagery

    OpenAIRE

    Hanan Hassan Ali Adlan

    2016-01-01

    Macroscopic images are kind of environments in which complex patterns are present. Satellite images are one of these classes where many patterns are present. This fact reflects the challenges in detecting patterns present in this kind of environments. SPOT1b satellite images provide valuable information. These images are affordable and can be applicable in wide applications. This paper demonstrates an approach to generate detection plane that visualize patterns present in the satellite image....

  3. Reproduction Patterns of Scleractinian Corals in the Central Red Sea

    KAUST Repository

    Bouwmeester, Jessica

    2013-12-01

    Early work on the reproductive seasonality of corals in the Red Sea suggested that corals exhibit temporal reproductive isolation, unlike on the Great Barrier Reef where many species spawn in synchrony. More recent work has however shown high synchrony in the maturity of gametes in Acropora species, suggesting multi-specific spawning is likely to occur in the Red Sea. In this thesis I investigate the patterns of coral reproduction in the central Red Sea. The spawning season in the central Red Sea lasts four months, from April to July and spawning occurs on nights around the full moon. During this period Acropora species show a peak of spawning in April, with some species spawning again in May. The level of synchrony, quantified with a spawning synchrony index, is comparable to other locations where multi-specific spawning has been reported. Observations over two consecutive years show that the synchrony of spawning was lower in spring 2012 than in spring 2011, and thus that spawning patterns are variable from one year to the other. Coral settlement patterns on artificial substrata confirmed a main spawning season in the spring but also supported reproductive data suggesting that some Porites spawn in October-November. Settlement was studied over 2.5 years on a reef, which had suffered recently from high mortality after a local bleaching event. Settlement appeared low but post-bleaching studies from other locations indicated similar abundances and showed that recruits generally did not increase until 5 years after the bleaching event. Abundance of juvenile corals however started to increase significantly three years after the bleaching. Successful recruitment, although low suggests that the coral assemblage on the affected reef will most likely recover as long as it is not affected by another disturbance.

  4. Texture Pattern Generation Using Clonal Mosaic

    Institute of Scientific and Technical Information of China (English)

    How Jiann Teo; Kok Cheong Wong

    2006-01-01

    In this paper, an effective system for synthesizing animal skin patterns on arbitrary polygonal surfaces is developed. To accomplish the task, a system inspired by the Clonal Mosaic (CM) model is proposed. The CM model simulates cells' reactions on arbitrary surface. By controlling the division, mutation and repulsion of cells, a regulated spatial arrangement of cells is formed. This arrangement of cells shows appealing result, which is comparable with those natural patterns observed from animal skin. However, a typical CM simulation process incurs high computational cost, where the distances among cells across a polygonal surface are measured and the movements of cells are constrained on the surface. In this framework, an approach is proposed to transform each of the original 3D geometrical planes of the surface into its Canonical Reference Plane Structure. This structure helps to simplify a 3D computational problem into a more manageable 2D problem. Furthermore, the concept of Local Relaxation is developed to optimally enhance the relaxation process for a typical CM simulation. The performances of the proposed solution methods have been verified with extensive experimental results.

  5. MRI in central nervous system infections: A simplified patterned approach

    Institute of Scientific and Technical Information of China (English)

    Krithika; Rangarajan; Chandan; J; Das; Atin; Kumar; Arun; Kumar; Gupta

    2014-01-01

    Recognition and characterization of central nervous system infections poses a formidable challenge to the neuro-radiologist.Imaging plays a vital role,the lesions typically being relatively inaccessible to tisue sampling.The results of an accurate diagnosis are endlessly re-warding,given the availability of excellent pharmaco-logical regimen.The availability of numerous magnetic resonance(MR)sequences which provide functional and molecular information is a powerful tool in the hands of the radiologist.However,the plethora of se-quences and the possibilities on each sequence is also intimidating,and often confusing as well as time con-suming.While a large number of reviews have already described in detail the possible imaging findings in each infection,we intend to classify infections based on their imaging characteristics.In this review we describe an algorithm for first classifying the imaging findings into patterns based on basic MR sequences(T1,T2 and enhancement pattern with Gadolinium),and then sub-classify them based on more advanced molecular and functional sequences(Diffusion,Perfusion,Susceptibili-ty imaging,MR Spectroscopy).This patterned approachis intended as a guide to radiologists in-training and in-practice for quickly narrowing their list of differentials when faced with a clinical challenge.The entire content of the article has also been summarised in the form of flow-charts for the purpose of quick reference.

  6. Identification of Bacteria by Patterns Generated from Odor Spectra

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    We use the power density spectra obtained by fluctuation-enhanced sensing of bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) to generate new, highly distinguishable, types of patterns based on the average slope of the spectra in different frequency ranges. Such plots can be considered as "fingerprints" of bacterial odors. Three different ways of pattern generation are tested, including a simple binary version. The obtained patterns are simple enough to identify the situation by the naked eye without a pattern recognizer.

  7. Hair patterns of the lower limb in Central Indian males.

    Science.gov (United States)

    Chaurasia, B D

    1977-08-01

    The distribution of hair of the right lower limb has been studied in a random sample of 220 healthy Central Indian males 17 to 45 years of age. The common hair patterns observed are the proximal phalangeal hair in all toes in 55.45%, the middle phalangeal hair in the third toe in 8.18%, the tibial on the dorsum of foot in 69.55%, and the pedo-cruro-femoral in the lower limb in 70.00% subjects. Comparison of these findings with those of the right upper limb shows that hairiness of the two limbs is correlated, that the dorsum of foot is less hairy than the dorsum of hand, and that the third and second toes are comparable with the fourth and third fingers, respectively, as regards their middle phalangeal hair. Comparison with the available literature shows that the Central Indian males resemble the Whites in having greater frequency of middle phalangeal hair than those of the Negroes, that the dorsum of feet of this population is less hairy than the White and more hairy than the Negroes, and that the general hairiness of the lower limb is more or less equal in the three groups of persons.

  8. Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation

    Directory of Open Access Journals (Sweden)

    G.S. Souza

    2012-10-01

    Full Text Available This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359. Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation modes. At the periphery, pattern reversal showed a larger number of reliable responses. Pattern pulse stimuli performed similarly to pattern reversal stimuli to generate reliable waveforms in R1 and R2. The advantage of using both protocols to study mfVEP responses is their complementarity: in some patients, reliable waveforms in specific sectors may be obtained with only one of the two methods. The joint analysis of pattern reversal and pattern pulse stimuli increased the rate of reliability for central sectors by 7.14% in R1, 5.35% in R2, 4.76% in R3, 3.57% in R4, 2.97% in R5, and 1.78% in R6. From R1 to R4 the reliability to generate mfVEPs was above 70% when using both protocols. Thus, for a very high reliability and thorough examination of visual performance, it is recommended to use both stimulation protocols.

  9. Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation.

    Science.gov (United States)

    Souza, G S; Schakelford, H B; Moura, A L A; Gomes, B D; Ventura, D F; Fitzgerald, M E C; Silveira, L C L

    2012-10-01

    This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation modes. At the periphery, pattern reversal showed a larger number of reliable responses. Pattern pulse stimuli performed similarly to pattern reversal stimuli to generate reliable waveforms in R1 and R2. The advantage of using both protocols to study mfVEP responses is their complementarity: in some patients, reliable waveforms in specific sectors may be obtained with only one of the two methods. The joint analysis of pattern reversal and pattern pulse stimuli increased the rate of reliability for central sectors by 7.14% in R1, 5.35% in R2, 4.76% in R3, 3.57% in R4, 2.97% in R5, and 1.78% in R6. From R1 to R4 the reliability to generate mfVEPs was above 70% when using both protocols. Thus, for a very high reliability and thorough examination of visual performance, it is recommended to use both stimulation protocols. PMID:22782556

  10. The Generation system of Textile Pattern draft Based on Quasi-regular Pattern Theory

    Directory of Open Access Journals (Sweden)

    Suyi Liu

    2009-10-01

    Full Text Available The quasi-regular patterns generated from hamiltonian has unique balanced symmetry. The patterns are quite suitable for the textile fabric. However the number of patterns just generated from hamiltonian are limited. Therefore in this paper a 110 of functions built by the methods of hamiltonian of superposition, nesting, combination and parameter variations, and it can increase the type and quantity. All of functions can generate fine patterns suited for textile fabric after computer graphics.The system of textile pattern draft is generated by Visual basics for the computer. The system allows individual selection of function and parameters to change the pattern and the color conditioning. In this way, it successfully achieves the purpose.

  11. Characteristic flow patterns generated by macrozoobenthic structures

    Science.gov (United States)

    Friedrichs, M.; Graf, G.

    2009-02-01

    A laboratory flume channel, equipped with an acoustic Doppler flow sensor and a bottom scanning laser, was used for detailed, non-intrusive flow measurements (at 2 cm s - 1 and 10 cm s - 1 ) around solitary biogenic structures, combined with high-resolution mapping of the structure shape and position. The structures were replicates of typical macrozoobenthic species commonly found in the Mecklenburg Bight and with a presumed influence on both, the near-bed current regime and sediment transport dynamics: a worm tube, a snail shell, a mussel, a sand mound, a pit, and a cross-stream track furrow. The flow was considerably altered locally by the different protruding structures (worm tube, snail, mussel and mound). They reduced the horizontal approach velocity by 72% to 79% in the wake zone at about 1-2 cm height, and the flow was deflected around the structures with vertical and lateral velocities of up to 10% and 20% of the free-stream velocity respectively in a region adjacent to the structures. The resulting flow separation (at flow Reynolds number of about 4000 and 20,000 respectively) divided an outer deflection region from an inner region with characteristic vortices and the wake region. All protruding structures showed this general pattern, but also produced individual characteristics. Conversely, the depressions (track and pit) only had a weak influence on the local boundary layer flow, combined with a considerable flow reduction within their cavities (between 29% and 53% of the free-stream velocity). A longitudinal vortex formed, below which a stagnant space was found. The average height affected by the structure-related mass flow rate deficit for the two velocities was 1.6 cm and 1.3 cm respectively (80% of height and 64%) for the protruding structures and 0.6 cm and 0.9 cm (90% and 127% of depth) for the depressions. Marine benthic soft-bottom macrozoobenthos species are expected to benefit from the flow modifications they induce, particularly in terms of

  12. An algorithm for generating quasiperiodic patterns and their approximants

    Indian Academy of Sciences (India)

    E A Lord; K Ramakrishnan; S Ranganathan

    2000-04-01

    An algorithm for projecting the interior of a hypercube in -dimensions on to an -dimensional subspace has been developed and incorporated into a computer program for generating quasiperiodic and periodic patterns in an -dimensional subspace. Some aspects of the resulting orthorhombic approximants to Penrose tiling patterns are discussed and illustrated.

  13. The Inspiration for the Motion Control of Robot from Central Pattern Generator of Animal's Locomotion Instruction%动物运动指令的中枢模式发生器对机器人运动控制的启示

    Institute of Scientific and Technical Information of China (English)

    李宏凯; 孙久荣; 戴振东

    2008-01-01

    动物运动指令的中枢模式发生器(central pattern generator, CPG)在动物的节律运动中发挥着重要的作用,对机器人的仿生控制方法研究具有借鉴意义.首先介绍了CPG的神经环路和控制机制,然后分析了组成CPG的非线性振荡器的典型数学模型,接着介绍了利用CPG进行机器人运动控制在国内外的发展现状,最后展望了其应用前景.

  14. Single-unit pattern generators for quadruped locomotion

    DEFF Research Database (Denmark)

    Morse, Gregory; Risi, Sebastian; Snyder, Charles R;

    2013-01-01

    locomotion can generate oscillations through popular techniques such as continuous time recurrent neural networks (CTRNNs) or sinusoidal input, they typically face a challenge in maintaining long-term stability. The aim of this paper is to address this challenge by introducing an effective alternative based...... on a new type of neuron called a single-unit pattern generator (SUPG). The SUPG, which is indirectly encoded by a compositional pattern producing network (CPPN) evolved by HyperNEAT, produces a flexible temporal activation pattern that can be reset and repeated at any time through an explicit trigger input...

  15. Dynamic array generation and pattern formation for optical tweezers

    DEFF Research Database (Denmark)

    Mogensen, P.C.; Glückstad, J.

    2000-01-01

    The generalised phase contrast approach is used for the generation of optical arrays of arbitrary beam shape, suitable for applications in optical tweezers for the manipulation of biological specimens. This approach offers numerous advantages over current techniques involving the use of computer......-generated holograms or diffractive optical elements. We demonstrate a low-loss system for generating intensity patterns suitable for the trapping and manipulation of small particles or specimens....

  16. Inductive class representation and its central role in pattern recognition

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, L. [Univ. of New Brunswick, Fredericton, New Brunswick (Canada)

    1996-12-31

    The definition of inductive learning (IL) based on the new concept of inductive class representation (ICR) is given. The ICR, in addition to the ability to recognize a noise-corrupted object from the class, must also provide the means to generate every element in the resulting approximation of the class, i.e., the emphasis is on the generative capability of the ICR. Thus, the IL problem absorbs the main difficulties associated with a satisfactory formulation of the pattern recognition problem. This formulation of the IL problem appeared gradually as a result of the development of a fundamentally new formal model of IL--evolving transformation system (ETS) model. The model with striking clarity suggests that IL is the basic process which produces all the necessary {open_quotes}structures{close_quotes} for the recognition process, which is built directly on top of it. Based on the training set, the IL process, constructs optimal discriminatory (symbolic) weighted {open_quotes}features{close_quotes} which induce the corresponding optimal (symbolic) distance measure. The distance measure is a generalization of the weighted Levenshtein, or edit, distance defined on strings over a finite alphabet. The ETS model has emerged as a result of an attempt to unify two basic, but inadequate, approaches to pattern recognition: the classical vector space based and the syntactic approaches. ETS also elucidates with remarkable clarity the nature of the interrelationships between the corresponding symbolic and numeric mechanisms, in which the symbolic mechanisms play a more fundamental part. The model, in fact, suggests the first formal definition of the symbolic mathematical structure and also suggests a fundamentally different, more satisfactory, way of introducing the concept of fuzziness. The importance of the ICR concept to semiotics and semantics should become apparent as soon as one fully realizes that it represents the class and specifies the semantics of the class.

  17. High Quality Test Pattern Generation and Boolean Satisfiability

    CERN Document Server

    Eggersglüß, Stephan

    2012-01-01

    This book provides an overview of automatic test pattern generation (ATPG) and introduces novel techniques to complement classical ATPG, based on Boolean Satisfiability (SAT).  A fast and highly fault efficient SAT-based ATPG framework is presented which is also able to generate high-quality delay tests such as robust path delay tests, as well as tests with long propagation paths to detect small delay defects. The aim of the techniques and methodologies presented in this book is to improve SAT-based ATPG, in order to make it applicable in industrial practice. Readers will learn to improve the performance and robustness of the overall test generation process, so that the ATPG algorithm reliably will generate test patterns for most targeted faults in acceptable run time to meet the high fault coverage demands of industry. The techniques and improvements presented in this book provide the following advantages: Provides a comprehensive introduction to test generation and Boolean Satisfiability (SAT); Describes a...

  18. Pattern Generation for Complex Data Using Hybrid Mining

    Directory of Open Access Journals (Sweden)

    Manish Kumar

    2013-07-01

    Full Text Available Combined mining is a hybrid mining approach for mining informative patterns from single or multipledata-sources, multiple-features extraction and applying multiple-methods as per the requirements. Datamining applications often involve complex data likemultiple heterogeneous data sources, different userpreference and create decision-making actions. Thecomplete useful information may not be obtained byusing single data mining method in the form of informative patterns as that would consume more time andspace. This paper implements hybrid or combined mining approach that applies Lossy-counting algorithmon each data-source to get the frequent data item-sets and then generates the combined association rules.Applying multi-feature approach, we generate incremental pair patterns and incremental cluster patterns.In multi-method combined mining approach, FP-growthand Bayesian Belief Network are combined togenerate classifier to get more informative knowledge. This paper uses two different data-sets to get moreuseful knowledge and compare the results.

  19. Double split ring slot FSS reflectarray for difference pattern generation

    OpenAIRE

    Zelenchuk, D.; Fusco, V.

    2013-01-01

    A report is presented on a split ring slot frequency selective surface (FSS) reflector whose element design and distribution allows generation of far-field difference patterns. The reflector operates by converting linearly polarised plane wave fronts into two orthogonal polarisations each with a deep null in the centre of the radiation pattern. The far-field measurement presented is in good agreement with the simulation and demonstrates a null depth of ?20dB in the centre of the radiation pat...

  20. COMBINED MINING APPROACH TO GENERATE PATTERNS FOR COMPLEX DATA

    Directory of Open Access Journals (Sweden)

    Sumit Kumar

    2013-02-01

    Full Text Available In Data mining applications, which often involve complex data like multiple heterogeneous data sources, user preferences, decision-making actions and business impacts etc., the complete useful information cannot be obtained by using single data mining method in the form of informative patterns as that would consume more time and space, if and only if it is possible to join large relevant data sources for discovering patterns consisting of various aspects of useful information. We consider combined mining as an approach for mining informative patterns from multiple data-sources or multiple-features or by multiple-methods as per the requirements. In combined mining approach, we applied Lossy-counting algorithm on each data-source to get the frequent data item-sets and then get the combined association rules. In multi-feature combined mining approach, we obtained pair patterns and cluster patterns and then generate incremental pair patterns and incremental cluster patterns, which cannot be directly generated by the existing methods. In multi-method combined mining approach, we combine FP-growth and Bayesian Belief Network to make a classifier to get more informative knowledge.

  1. Robust central pattern generators for embodied hierarchical reinforcement learning

    NARCIS (Netherlands)

    M. Snel; S. Whiteson; Y. Kuniyoshi

    2011-01-01

    Hierarchical organization of behavior and learning is widespread in animals and robots, among others to facilitate dealing with multiple tasks. In hierarchical reinforcement learning, agents usually have to learn to recombine or modulate low-level behaviors when facing a new task, which costs time t

  2. Modeling Patterns of Precipitation Phase in the Central Sierra Nevada

    Science.gov (United States)

    Strikas, O.; Pavelsky, T.

    2013-12-01

    Snowpack provides 75% of summer hydrologic flow in the western United States. This summer flow is vitally important in California, the country's leading producer of agriculture, with $43.5 billion dollars in cash receipts in 2011. Snowpack in the California Sierra Nevada has declined by approximately half from 1900 to 1990. In this study, we use the Weather Research and Forecasting (WRF) regional climate model at a 3km resolution to understand the critical temperature window at which both snow and rain fall for the Central Sierra Nevada during the 2002 water year. Results suggest that temperature and snow fraction [snowfall / (snowfall + rainfall)] share a logistic relationship with the snow fraction being 1 until approximately 272 K, then the snow fraction decreases by approximately 22%/K leveling at 0 snow fraction at 276.5 K. We further examine the spatial patterns of temperatures, precipitation amounts, and precipitation types in the Sierra Nevada to determine the areas of greatest potential snow to rain transition under a future warmer climate. Preliminary results suggest that the high risk areas are at the low to mid elevations. This research provides evidence that even a minor increase in temperature (+0.5 K) will yield changes in spring and summer hydrographs for the region. The spatial variability of IPCC temperature regime change for 2050 and 2100 will be downscaled for a higher resolution prediction of precipitation. It is currently under investigation how the proposed IPCC (A1 and B2) predictions of climate change for the region by 2050 (+2.7 K; +1.6 K ) and 2100 (+4.4 K; +2.7 K) will alter the corresponding annual river hydrographs. Given the complex topography of the Sierra Nevada, several spatial interpolations using GIS and statistical algorithms will be executed to render this high resolution (3km) output. Other future work with collaborators intends to model the agricultural risk associated with our predicted changes. This plot demonstrates the

  3. Pattern Visualization Through Detection Plane Generation for Macroscopic Imagery

    Directory of Open Access Journals (Sweden)

    Hanan Hassan Ali Adlan

    2016-02-01

    Full Text Available Macroscopic images are kind of environments in which complex patterns are present. Satellite images are one of these classes where many patterns are present. This fact reflects the challenges in detecting patterns present in this kind of environments. SPOT1b satellite images provide valuable information. These images are affordable and can be applicable in wide applications. This paper demonstrates an approach to generate detection plane that visualize patterns present in the satellite image. The detection plane uses rough neural network to provide optimal representation in backpropagation architecture. Rough set theory combined with multilayer perceptron constitutes the rough neural network. Reduction in the feature dimensionality via the rough module improves the recognition ability of the neural network. It is found that the rough module provides the neural network with optimal features. The ability of the neural network to efficiently detect and visualize the pattern stems from a developed extraction algorithm. The result of the hybrid architecture provides the plane with the best features that visualize the phenomena under investigation. Together with the novel extraction algorithm, the developed system provides a tool to visualize patterns present in SPOT1b Satellite image.

  4. Continuities and changes in infant attachment patterns across two generations.

    Science.gov (United States)

    Raby, K Lee; Steele, Ryan D; Carlson, Elizabeth A; Sroufe, L Alan

    2015-01-01

    This study examined the intergenerational continuities and changes in infant attachment patterns within a higher-risk longitudinal sample of 55 female participants born into poverty. Infant attachment was assessed using the Strange Situation when participants were 12 and 18 months as well as several decades later with participants' children. Paralleling earlier findings from this sample on the stability of attachment patterns from infancy to young adulthood, results provided evidence for intergenerational continuities in attachment disorganization but not security. Children of adults with histories of infant attachment disorganization were at an increased risk of forming disorganized attachments. Although changes in infant attachment patterns across the two generations were not correlated with individuals' caregiving experiences or interpersonal stresses and supports during childhood and adolescence, higher quality social support during adulthood was associated with intergenerational changes from insecure to secure infant-caregiver attachment relationships. PMID:26213155

  5. Precise packet loss pattern generation by intentional interference

    OpenAIRE

    He Z.; Voigt T

    2011-01-01

    Abstract—Intermediate-quality links often cause vulnerable connectivity in wireless sensor networks, but packet losses caused by such volatile links are not easy to trace. In order to equip link layer protocol designers with a reliable test and debugging tool, we develop a reactive interferer to generate packet loss patterns precisely. By using intentional interference to emulate parameterized lossy links with very low intrusiveness, our tool facilitates both robustness evaluation of proto...

  6. An Assessment of Future Patterns of Security in Central Asia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Since the disintegration of the Soviet Union in the early 1990s, various social problems left over have emerged in some Central Asian states, thus threatening social stability in the region. Under globalization, the former Soviet republics in Central Asia have made great efforts to develop constructive relations with others in the hope of strengthening their security. However, the threat of terrorism, extremism and separatism still exists. These non-traditional security issues play a role in current international politics, and the countries in the region are trylng to meet new challenges.

  7. Distributed generation and centralized power system in Thailand

    DEFF Research Database (Denmark)

    Sukkumnoed, Decharut

    The paper examines and discusses conflicts between the development of distributed power and centralized power system in Thailand.......The paper examines and discusses conflicts between the development of distributed power and centralized power system in Thailand....

  8. Use of design pattern layout for automatic metrology recipe generation

    Science.gov (United States)

    Tabery, Cyrus; Page, Lorena

    2005-05-01

    As critical dimension control requirements become more challenging, due to complex designs, aggressive lithography, and the constant need to shrink,metrology recipe generation and design evaluation have also become very complex. Hundreds of unique sites must be measured and monitored to ensure good device performance and high yield. The use of the design and layout for automated metrology recipe generation will be critical to that challenge. The DesignGauge from Hitachi implements a system enabling arbitrary recipe generation and control of SEM observations performed on the wafer, based only on the design information. This concept for recipe generation can reduce the time to develop a technology node from RET and design rule selection, through OPC model calibration and verification, and all the way to high volume manufacturing. Conventional recipe creation for a large number of measurement targets requires a significant amount of engineering time. Often these recipes are used only once or twice during mask and process verification or OPC calibration data acquisition. This process of manual setup and analysis is also potentially error prone. CD-SEM recipe creation typically requires an actual wafer, so the recipe creation cannot occur until the scanner and reticle are in house. All of these problems with conventional CD SEM lead to increased development time and reduced final process quality. The new model of CD-SEM recipe generation and management utilizes design-to-SEM matching technology. This new technology extracts an idealized shape from the designed pattern, and utilizes the shape information for pattern matching. As a result, the designed pattern is used as basis for the template instead of the actual SEM image. Recipe creation can be achieved in a matter of seconds once the target site list is finalized. The sequence of steps for creating a recipe are: generate a target site list, pass the design polygons (GDS) and site list to the CD SEM, define references

  9. Pattern generation requirements for mask making beyond 130 nm

    Science.gov (United States)

    Abboud, Frank E.; Gesley, Mark A.; Maldonado, Juan R.

    1998-06-01

    It is commonly accepted in the semiconductor industry that optical lithography will be the most cost-effective solution for 150 nm and 130 nm device generations. Some selected layers at the 130 nm device generation may be produced using electron-beam direct-write or x-ray during the development phase. However, for the production phase, it is expected that 193 nm optical lithography with reticle enhancement techniques such as optical proximity correction (OPC) and phase shift masks (PSM) will be the technology of choice. What about post 193 nm. The range of solutions is more diverse and a clear winner has not yet emerged. The topic, however, is becoming more visible and has taken a prominent place in technical conferences in the past year. The five leading potential alternatives to optical lithography are proximity x-ray, e-beam projection (EBP), extended UV (EUV), ion projection lithography (IPL), and e-beam direct write. The search for the right answer will most likely continue for a few years, and possibly more than one alternative will emerge as an effective solution at and below 100 nm. All of the alternatives, with the exception of e-beam direct write, have one thing in common, the mask. Except for proximity x- ray, all solutions at present envision a 4x reduction of the mask-to-wafer image plane. Instead of chrome-coated quartz, a silicon wafer substrate is used. Aside from patterning, mask fabrication varies depending on the lithography absorbing substrate, and EUV requires a reflective multilayer stack. Most key lithography requirements needed to pattern the imaging layer are common to all of the candidates, at least for the reduction methods. For x-ray lithography, the requirements are significantly more stringent but at a smaller field. This paper will consolidate the requirements of the various types of masks from a pattern generation point of view and will focus on the pattern generation tool requirements to meet those mask requirements. In addition, it

  10. Costs and revenues of centrally generated electricity in the Netherlands

    International Nuclear Information System (INIS)

    The existing statistics on centrally generated electricity in the Netherlands do not give an integral picture of costs and revenues. This report intends to fill this gap. It contains a systematic overview of the costs of fuel, capital, other generation costs and the costs of distribution. A detailed overview is given for 1976 and 1977 and the main trends in the period 1950/1980 are considered. From these trends it appears that the increase of revenues from electricity in the last 30 years (from f 400 mln in 1950 to f 8,000 mln in 1980) has been caused by a tenfold increase of electricity consumption and a doubling of the average nominal kWh-charge. The quadrupling of fuel costs in the last 7 years is responsible for the doubling of this kWh-charge. A correction for inflation (since 1950 5%/year) shows, however, that the real kWh-charge in 1980 is only half the kWh-charge in 1950. A discussion on electricity from incineration is included. Because of increasing fuel charges and the difficulties with the disposal of domestic waste this option must be taken into account for future energy supply. The costs of nuclear power are treated in some detail, partly because of the public interest in this subject. It is shown that the costs of electricity from existing nuclear capacity and the estimates of these costs for new nuclear capacity are subject to an increasing trend. This last statement is true as well for electricity from conventional capacity

  11. BUILDOUT AND UPGRADE OF CENTRAL EMERGENCY GENERATOR SYSTEM, GENERATOR 3 AND 4 ELECTRICAL INSTALLATION

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Seifert; G. Shawn West; Kurt S. Myers; Jim Moncur

    2006-07-01

    SECTION 01000—SUMMARY OF WORK PART 1—GENERAL 1.1 SUMMARY The work to be performed under this project consists of providing the labor, equipment, and materials to perform "Buildout and Upgrade of Central Emergency Generator System, Generator 3 and 4 Electrical Installation" for the National Aeronautics and Space Administration at the Dryden Flight Research Center (NASA/DFRC), Edwards, California 93523. All modifications to existing substations and electrical distribution systems are the responsibility of the contractor. It is the contractor’s responsibility to supply a complete and functionally operational system. The work shall be performed in accordance with these specifications and the related drawings. The work of this project is defined by the plans and specifications contained and referenced herein. This work specifically includes but is not limited to the following: Scope of Work - Installation 1. Install all electrical wiring and controls for new generators 3 and 4 to match existing electrical installation for generators 1 and 2 and in accordance with drawings. Contractor shall provide as-built details for electrical installation. 2. Install battery charger systems for new generators 3 and 4 to match existing battery charging equipment and installation for generators 1 and 2. This may require exchange of some battery charger parts already on-hand. Supply power to new battery chargers from panel and breakers as shown on drawings. Utilize existing conduits already routed to generators 3 and 4 to field route the new wiring in the most reasonable way possible. 3. Install electrical wiring for fuel/lube systems for new generators 3 and 4 to match existing installation for generators 1 and 2. Supply power to lube oil heaters and fuel system (day tanks) from panel and breakers as shown on drawings. Utilize existing conduits already routed to generators 3 and 4 to field route the new wiring in the most reasonable way possible. Add any conduits necessary to

  12. Pattern Recognition on Read Positioning in Next Generation Sequencing

    Science.gov (United States)

    Byeon, Boseon; Kovalchuk, Igor

    2016-01-01

    The usefulness and the utility of the next generation sequencing (NGS) technology are based on the assumption that the DNA or cDNA cleavage required to generate short sequence reads is random. Several previous reports suggest the existence of sequencing bias of NGS reads. To address this question in greater detail, we analyze NGS data from four organisms with different GC content, Plasmodium falciparum (19.39%), Arabidopsis thaliana (36.03%), Homo sapiens (40.91%) and Streptomyces coelicolor (72.00%). Using machine learning techniques, we recognize the pattern that the NGS read start is positioned in the local region where the nucleotide distribution is dissimilar from the global nucleotide distribution. We also demonstrate that the mono-nucleotide distribution underestimates sequencing bias, and the recognized pattern is explained largely by the distribution of multi-nucleotides (di-, tri-, and tetra- nucleotides) rather than mono-nucleotides. This implies that the correction of sequencing bias needs to be performed on the basis of the multi-nucleotide distribution. Providing companion software to quantify the effect of the recognized pattern on read positioning, we exemplify that the bias correction based on the mono-nucleotide distribution may not be sufficient to clean sequencing bias. PMID:27299343

  13. Stochastic Generation of Wind Patterns over Lake Geneva

    Science.gov (United States)

    Barry, D. A.; Barry, C. E.; Razmi, A. M.; Lemmin, U.; Le Dantec, N.

    2011-12-01

    stochastic generator of wind-pattern indices, i.e., the INAR(1) model produces a sequence of integers, each of which corresponds to a wind pattern. For a given index, the aforementioned binned COSMO wind fields were sampled randomly to produce the stochastic wind-field sequence.

  14. Children with central and peripheral neurologic disorders have distinguishable patterns of dysphagia on videofluoroscopic swallow study

    NARCIS (Netherlands)

    Engel-Hoek, L. van den; Erasmus, C.E.; Hulst, K. van; Arvedson, J.C.; Groot, I.J.M. de; Swart, B.J.M. de

    2014-01-01

    To determine whether findings on videofluoroscopic swallow studies reveal different patterns of dysphagia between children with central and peripheral neurologic disorders, a retrospective study of 118 videofluoroscopic swallow studies was completed. There were 3 groups: cerebral palsy with only spa

  15. Anthropogenic soils in central Amazonia: farmers’ practices, agrobiodiversity and land-use patterns

    NARCIS (Netherlands)

    Braga Junqueira, A.

    2015-01-01

    Keywords: Terra Preta; Amazonian Dark Earths; Shifting cultivation; Homegardens; Intensification; Diversification; Smallholder farming. André Braga Junqueira (2015). Anthropogenic soils in central Amazonia: farmers’ practices, agrobiodiversity and land-use patterns. PhD thesis, Wagening

  16. Generation of Viable Cell and Biomaterial Patterns by Laser Transfer

    Science.gov (United States)

    Ringeisen, Bradley

    2001-03-01

    In order to fabricate and interface biological systems for next generation applications such as biosensors, protein recognition microarrays, and engineered tissues, it is imperative to have a method of accurately and rapidly depositing different active biomaterials in patterns or layered structures. Ideally, the biomaterial structures would also be compatible with many different substrates including technologically relevant platforms such as electronic circuits or various detection devices. We have developed a novel laser-based technique, termed matrix assisted pulsed laser evaporation direct write (MAPLE DW), that is able to direct write patterns and three-dimensional structures of numerous biologically active species ranging from proteins and antibodies to living cells. Specifically, we have shown that MAPLE DW is capable of forming mesoscopic patterns of living prokaryotic cells (E. coli bacteria), living mammalian cells (Chinese hamster ovaries), active proteins (biotinylated bovine serum albumin, horse radish peroxidase), and antibodies specific to a variety of classes of cancer related proteins including intracellular and extracellular matrix proteins, signaling proteins, cell cycle proteins, growth factors, and growth factor receptors. In addition, patterns of viable cells and active biomolecules were deposited on different substrates including metals, semiconductors, nutrient agar, and functionalized glass slides. We will present an explanation of the laser-based transfer mechanism as well as results from our recent efforts to fabricate protein recognition microarrays and tissue-based microfluidic networks.

  17. Distinct rhythmic locomotor patterns can be generated by a simple adaptive neural circuit: biology, simulation, and VLSI implementation.

    Science.gov (United States)

    Ryckebusch, S; Wehr, M; Laurent, G

    1994-12-01

    Rhythmic motor patterns can be induced in leg motor neurons of isolated locust thoracic ganglia by bath application of pilocarpine. We observed that the relative phases of levators and depressors differed in the three thoracic ganglia. Assuming that the central pattern generating circuits underlying these three segmental rhythms are probably very similar, we developed a simple model circuit that can produce any one of the three activity patterns and characteristic phase relationships by modifying a single synaptic weight. We show results of a computer simulation of this circuit using the neuronal simulator NeuraLOG/Spike. We built and tested an analog VLSI circuit implementation of this model circuit that exhibits the same range of "behaviors" as the computer simulation. This multidisciplinary strategy will be useful to explore the dynamics of central pattern generating networks coupled to physical actuators, and ultimately should allow the design of biologically realistic walking robots.

  18. Simplified Process for Manufacturing Macroscale Patterns to Enhance Voltage Generation by a Triboelectric Generator

    Directory of Open Access Journals (Sweden)

    Jun-Ho Yang

    2015-11-01

    Full Text Available This paper proposes a simple, yet effective and affordable, manufacturing process to enhance the overall efficiency of voltage generation by a triboelectric generator (TEG using 3D printers for energy-harvesting applications. The proposed method can be classified as macroscale surface patterning, in contrast to micro- and nanoscale patterning of TEG proposed in previous studies. Experiments were conducted using a designed test-bed system that allowed the control of external factors, such as the magnitude and frequency of the frictional force and the relative humidity, and an output voltage increase of up to 67% was obtained from a TEG with macroscale patterns that increased the surface area by 14%. The peak voltage generated by the TEG was as high as 18 V, and the addition of a designed analog circuit that uses no external power enabled storage of a DC voltage of 0.4 V. In comparison with previous methods that employ micro- or nanoscale patterns, the proposed patterning method is faster and more suitable for mass production.

  19. The generation of vertebral segmental patterning in the chick embryo.

    Science.gov (United States)

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-06-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.

  20. Pattern recognition receptors and central nervous system repair.

    Science.gov (United States)

    Kigerl, Kristina A; de Rivero Vaccari, Juan Pablo; Dietrich, W Dalton; Popovich, Phillip G; Keane, Robert W

    2014-08-01

    Pattern recognition receptors (PRRs) are part of the innate immune response and were originally discovered for their role in recognizing pathogens by ligating specific pathogen associated molecular patterns (PAMPs) expressed by microbes. Now the role of PRRs in sterile inflammation is also appreciated, responding to endogenous stimuli referred to as "damage associated molecular patterns" (DAMPs) instead of PAMPs. The main families of PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), RIG-like receptors (RLRs), AIM2-like receptors (ALRs), and C-type lectin receptors. Broad expression of these PRRs in the CNS and the release of DAMPs in and around sites of injury suggest an important role for these receptor families in mediating post-injury inflammation. Considerable data now show that PRRs are among the first responders to CNS injury and activation of these receptors on microglia, neurons, and astrocytes triggers an innate immune response in the brain and spinal cord. Here we discuss how the various PRR families are activated and can influence injury and repair processes following CNS injury.

  1. Multi-neuronal refractory period adapts centrally generated behaviour to reward.

    Directory of Open Access Journals (Sweden)

    Christopher A Harris

    Full Text Available Oscillating neuronal circuits, known as central pattern generators (CPGs, are responsible for generating rhythmic behaviours such as walking, breathing and chewing. The CPG model alone however does not account for the ability of animals to adapt their future behaviour to changes in the sensory environment that signal reward. Here, using multi-electrode array (MEA recording in an established experimental model of centrally generated rhythmic behaviour we show that the feeding CPG of Lymnaea stagnalis is itself associated with another, and hitherto unidentified, oscillating neuronal population. This extra-CPG oscillator is characterised by high population-wide activity alternating with population-wide quiescence. During the quiescent periods the CPG is refractory to activation by food-associated stimuli. Furthermore, the duration of the refractory period predicts the timing of the next activation of the CPG, which may be minutes into the future. Rewarding food stimuli and dopamine accelerate the frequency of the extra-CPG oscillator and reduce the duration of its quiescent periods. These findings indicate that dopamine adapts future feeding behaviour to the availability of food by significantly reducing the refractory period of the brain's feeding circuitry.

  2. The Central Electricity Generating Board flask test project

    International Nuclear Information System (INIS)

    In 1981, the UK Central Electricity Generating Board set up a wide-ranging programme of theoretical and experimental work to develop a detailed understanding of the way in which Magnox flasks behave in severe transport accidents. Specific objectives of the project included an investigation into the validity of the use of scale models to represent full-size flask behaviour and the relevance of the IAEA regulatory tests in relation to real transport accidents. In all, over a hundred tests on flask components, model flasks and other test pieces were conducted, culminating in the drop testing of a full-sized Magnox flask and a simulated rail crash test carried out in public in July 1984. The project was based on a steady progression from the study of fundamental principles to the execution of the train crash. Extensive use was made of experimental drop-test facilities and computer-aided analytical techniques, such as the finite element method. The project confirmed that, with some important exceptions, linear scalability can be applied with confidence to predict flask behaviour under impact loading. Where those exceptions were encountered, some guidance was obtained as to how it should be properly accounted for when interpreting scale model data. Good correlation was achieved between finite element analyses (carried out using DYNA-3D and ANSYS) and experimental results. The knowledge gained as a result of developing and running the finite element model proved to be invaluable in developing a high degree of understanding of flask impact behaviour. This knowledge ultimately allowed a series of very simple mathematical models to be developed and used as engineering tools in other studies. (author)

  3. A Hierarchical Connectionist Central Pattern Generator Model for Controlling Three-dimensional Gaits of Snake-like Robots%面向蛇形机器人的三维步态控制的层次化联结中枢模式生成器模型

    Institute of Scientific and Technical Information of China (English)

    杨贵志; 马书根; 李斌; 王明辉

    2013-01-01

    提高蛇形机器人的三维运动控制能力是提高蛇形机器人环境适应能力的关键之一.虽然联结中枢模式生成器(Connectionist central pattern generator,CCPG)模型具有复杂度小、适合硬件实现等优点,但是目前的CCPG模型难以生成相位协调的多自由度运动的控制信号,从而限制了它的三维步态控制能力.本文根据生物CPG机制的分层结构和运动神经元的功能,提出一个有层次化结构的CCPG (Hierarchical CCPG,HCCPG)模型.HCCPG模型由基本节律信号生成层、模式形成层、运动信号调整层这三个部分组成.运动信号调整层的运动神经元能够独立地对模式形成层的输出信号的幅值、相位等进行调整,从而较好地解决了CCPG模型难以生成相位协调的多自由度运动控制信号的问题.HCCPG模型具有步态控制能力强、复杂度小、有良好的扩展性等优点,从而适合用于控制三维步态.在HCCPG模型的基础上提出一个三维步态控制方法.仿真验证了这个控制方法的有效性.

  4. Research on Optimal Development Pattern of Yunnan Central Economic Region

    Institute of Scientific and Technical Information of China (English)

    Diego Salmero; Suman Rana

    2012-01-01

    By the case study on the Urban Agglomeration Plan of Yunnan Central Economic Region (YCER), which is jointly made by Chinese and Swiss scholars, with the adoption of GIS and traditional urban planning methods, this paper uses multiple scenarios to analyze four development models of "Scattered Yunnan," "Regional Yunnan," "Metropolitan Yunnan" and "Network Yunnan." It also explores the relatively rational scenarios for the future development of YCER, i.e., up to 2030, the development model of YCER will be "Regional," and after 2030 it will be "Network." In this way, YCER will be developed stably and methodically, and finally achieve the unification of ecological safety, intensified energy and resources, as well as prosperous economy.

  5. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia.

    Science.gov (United States)

    Bronzwaer, Anne-Sophie G T; Verbree, Jasper; Stok, Wim J; van Buchem, Mark A; Daemen, Mat J A P; van Osch, Matthias J P; van Lieshout, Johannes J

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at -50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  6. Pattern recognition receptors and central nervous system repair

    Science.gov (United States)

    Kigerl, Kristina A.; de Rivero Vaccari, Juan Pablo; Dietrich, W. Dalton

    2016-01-01

    Pattern recognition receptors (PRRs) are part of the innate immune response and were originally discovered for their role in recognizing pathogens by ligating specific pathogen associated molecular patterns (PAMPs) expressed by microbes. Now the role of PRRs in sterile inflammation is also appreciated, responding to endogenous stimuli referred to as “damage associated molecular patterns” (DAMPs) instead of PAMPs. The main families of PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), RIG-like receptors (RLRs), AIM2-like receptors (ALRs), and C-type lectin receptors. Broad expression of these PRRs in the CNS and the release of DAMPs in and around sites of injury suggest an important role for these receptor families in mediating post-injury inflammation. Considerable data now show that PRRs are among the first responders to CNS injury and activation of these receptors on microglia, neurons, and astrocytes triggers an innate immune response in the brain and spinal cord. Here we discuss how the various PRR families are activated and can influence injury and repair processes following CNS injury. PMID:25017883

  7. Electric vehicle charge patterns and the electricity generation mix and competitiveness of next generation vehicles

    International Nuclear Information System (INIS)

    Highlights: • The energy system of whole of Japan is analyzed in this study. • An advanced model based on MARKAL is used for the energy system analysis. • The impact of charge patterns of EVs on electricity generation mix is evaluated. • Technology competitiveness of the next generation vehicles is also evaluated. - Abstract: The nuclear accident of 2011 brought about a reconsideration of the future electricity generation mix of power systems in Japan. A debate on whether to phase out nuclear power plants and replace them with renewable energy sources is taking place. Demand-side management becomes increasingly important in future Japanese power systems with a large-scale integration of renewable energy sources. This paper considers the charge control of electric vehicles (EVs) through demand-side management. There have been many studies of the control or operation methods of EVs known as vehicle-to-grid (V2G), and it is important to evaluate both their short-term and long-term operation. In this study, we employ energy system to evaluate the impact of the charge patterns of EVs on both the electricity generation mix and the technology competitiveness of the next generation vehicles. An advanced energy system model based on Market Allocation (MARKAL) is used to consider power system control in detail

  8. Cat and dog ownership and management patterns in central Italy.

    Science.gov (United States)

    Slater, Margaret R; Di Nardo, Antonio; Pediconi, Ombretta; Villa, Paolo Dalla; Candeloro, Luca; Alessandrini, Barbara; Del Papa, Stefania

    2008-07-15

    Three hundred and ninety-seven randomly selected households were interviewed by telephone to determine the numbers and management of owned cats and dogs in the Teramo Province of Italy. The households were selected using stratified random sampling for each municipality; municipalities were combined into coastal, central hills and mountain regions for analysis. The interviews were completed during May and June of 2004 with a response rate of 74% (397/536). Forty-six percent of households (n=181) owned pets; 15% of all households (n=60) owned cats and 33% (n=130) owned dogs. Twenty-seven of these households (7%) owned both cats and dogs. Data were provided on 91 cats evenly divided between males and females. The median age was 3 years (range 0.2-10 years). Forty-one percent of cats (36/87) entered the household as strays. Nearly half lived entirely outside. Seventy percent (62/88) had visited a veterinarian at least once; 43% (39/91) were sterilized. About 1/3 had had a litter and all litters were considered accidental rather than planned. Age, indoor/outdoor status, veterinarian visit and region were all associated with sterilization. Age, confined to a yard, veterinary visit and region were associated with allowing the cat to roam freely. Data were provided on 182 dogs. Sixty-two percent (113/181) were male, with a median age of 4 years (range newborn to 17 years) and 40% (72/181) were purebred. Almost half were acquired as a gift. Sixty-two percent (112/180) were kept entirely outside despite the fact that 82% (147/180) were considered companions rather than working dogs. Almost all of the dogs had been to a veterinarian at least once; only 20% (n=29) were sterilized. Male dogs were significantly less likely to be sterilized than females. Almost half the dogs had had at least one litter. Seventy-six percent (137/180) of dogs knew some basic commands. Sex, source and training to sit/stay/come were significantly associated with whether the dog was sterilized. Dog

  9. Repetition rate tunable ultra-short optical pulse generation based on electrical pattern generator

    Institute of Scientific and Technical Information of China (English)

    Xin Fu; Hongming Zhang; Meng Yan; Minyu Yao

    2009-01-01

    @@ An actively mode-locked laser with tunable repetition rate is proposed and experimentally demonstrated based on a programmable electrical pattern generator.By changing the repetition rate of the electrical patterns applied on the in-cavity modulator, the repetition rate of the output optical pulse sequences changes accordingly while the pulse width of the optical pulse train remains almost constant.In other words, the output ultra-short pulse train has a tunable duty cycle.In a proof-of-principle experiment, optical pulses with repetition rates of 10, 5, 2.5 and 1.25 GHz are obtained by adjusting the electrical pattern applied on the in-cavity modulator while their pulse widths remain almost unchanged.

  10. The Birth of a "Green" Generation? Generational Dynamics of Resource Consumption Patterns

    OpenAIRE

    Büttner, T.; Grubler, A

    1995-01-01

    The article discusses a generational perspective on changes in lifestyles and consumption patterns that complement more traditional approaches of heterogeneity and path dependency of human behavior. An application is given, in developing a model of cohort and gender-specific diffusion of technological artifacts, applied to the case of car ownership in Germany. The article concludes with a number of research questions to address the complexities of changes in human behavior from an interdiscip...

  11. Learning Techniques for Automatic Test Pattern Generation using Boolean Satisfiability

    Directory of Open Access Journals (Sweden)

    Liu Xin

    2013-07-01

    Full Text Available Automatic Test Pattern Generation (ATPG is one of the core problems in testing of digital circuits. ATPG algorithms based on Boolean Satisfiability (SAT turned out to be very powerful, due to great advances in the performance of satisfiability solvers for propositional logic in the last two decades. SAT-based ATPG clearly outperforms classical approaches especially for hard-to-detect faults. But its inaccessibility of structural information and don’t care, there exists the over-specification problem of input patterns. In this paper we present techniques to delve into an additional layer to make use of structural properties of the circuit and value justification relations to a generic SAT algorithm. It joins binary decision graphs (BDD and SAT techniques to improve the efficiency of ATPG. It makes a study of inexpensive reconvergent fanout analysis of circuit to gather information on the local signal correlation by using BDD learning, then uses the above learned information to restrict and focus the overall search space of SAT-based ATPG. The learning technique is effective and lightweight. Experimental results show the effectiveness of the approach.

  12. A Cyclic Inhibitory Central Pattern Generator Control Method Integrated with Mechanical Oscillators for Snake Robots%融合机械元的蛇形机器人循环抑制中枢模式发生器控制方法

    Institute of Scientific and Technical Information of China (English)

    唐超权; 王明辉; 李斌; 马书根

    2013-01-01

    To solve the problem that there is no basis for choosing control signals and sensor information for central pattern generator (CPG) control of snake robots, a cyclic inhibitory CPG control method with mechanical oscillators is proposed. Firstly, the mechanical oscillators reformed from snake robot dynamical equations are introduced into the cyclic inhibitory CPG model. Secondly, an improved Matsuoka neuron is proposed so that the neuron and mechanical oscillator can be expressed in a uniform way. Thirdly, the relationship of parameters in the cyclic inhibitory CPG model with mechanical oscillators is illustrated, and the relationship expression of the control signal and sensor information for snake robots and the CPG states is given. Finally, the proposed method is verified with simulation, and the simulation results are analyzed. In this method, there are clear definitions for the control signals and sensor information of snake robots, and the computation complexity of CPG is decreased because neuron computation in CPG is replaced with physical structure of mechanical oscillators.%针对蛇形机器人中枢模式发生器(CPG)控制中控制信号以及传感信息缺少选择依据的问题,提出了一种融合了机械元的循环抑制CPG控制方法.首先,将蛇形机器人本体动力学方程改造为机械元引入循环抑制CPG模型.其次,提出了改进的Matsuoka神经元,从而使得神经元与机械元具有一致的表达形式.再次,分析了融入机械元的循环抑制CPG模型中的参数关系,并给出了控制信号和传感信息与CPG状态量关系的表达式.最后,利用仿真对所提出的方法进行了验证,并对产生结果进行了分析.该方法中蛇形机器人的控制信号与传感信息都具有明确的定义,且由于用机械元的物理结构代替了神经元的计算,降低了CPG的计算量.

  13. US central station nuclear electric generating units: significant milestones

    International Nuclear Information System (INIS)

    Listings of US nuclear power plants include significant dates, reactor type, owners, and net generating capacity. Listings are made by state, region, and utility. Tabulations of status, schedules, and orders are also presented

  14. Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants

    DEFF Research Database (Denmark)

    Bjerregaard, P; Jørgensen, M E; Andersen, S;

    2002-01-01

    OBJECTIVE: To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization. DESIGN: Cross-sectional, population-based epidemiological study. SUBJECTS: A total of 2046 adult Greenlanders (Inuit), 61% of those...... women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland. CONCLUSION: BMI and central fat patterning decrease...

  15. A Walking Rehabilitation System Using Electrical Stimulation Based on Central Pattern Generator Control: Design and Experiment%基于中枢模式发生器控制的电刺激步行康复系统设计与实验

    Institute of Scientific and Technical Information of China (English)

    王颖; 张定国

    2012-01-01

    研发功能性电刺激(FES)康复系统来实现下肢瘫痪病人的行走运动.控制器采用基于中枢模式发生器(CPG)的仿生控制机理.针对基于递归神经振荡器的CPG模型,研究关键参数(激励性输入、时间常数、感觉反馈、输出阈值)对CPG输出幅值、频率、相位以及占空比的影响.建立包含12个神经元的CPG网络,以控制双腿的4个关节(左/右髋关节和膝关节)和八组肌群(左/右髂腰肌、臀大肌、股直肌和腘绳肌).所搭建的实验系统和平台,包括悬吊减重系统、助行系统、电刺激系统和运动检测系统.在正常受试者参与的实验中,受试者在CPG控制的电刺激作用下产生非自主行走运动.实验结果表明,受试者双腿的髋关节和膝关节角度与正常人自主行走时的数据达到定性吻合,验证所设计的CPG控制器在FES康复系统中的可行性与有效性.%A walking rehabilitation system for paralyzed patients using functional electrical stimulation ( FES) technique was developed in this work. A kind of biological motor control mechanism, central pattern generator (CPG) , was adopted as the controller of the system. Targeting the CPG model named as recurrent neural oscillator, the effects of CPG parameters ( excitation input, time constant, sensory feedback, and output threshold) on output amplitude, frequency, phase, and duty cycle were studied. The CPG network containing 12 neurons was developed in order to control four joints (left/right hip joints and knee joints) with eight muscle groups ( left/right iliopsoas, glutaeus maximus, rectus femoris, and hamstrings) of lower limbs. FES experimental system and platform is constructed, which includes suspension system, treadmill, FES system and motion measurement system. Experiments were conducted on healthy subjects to generate the involuntary walking movements via FES based on CPG control. The experimental results show that the hip and knee joint angles measured

  16. Motor pattern specification by dual descending pathways to a lobster rhythm-generating network.

    Science.gov (United States)

    Combes, D; Meyrand, P; Simmers, J

    1999-05-01

    In the European lobster Homarus gammarus, rhythmic masticatory movements of the three foregut gastric mill teeth are generated by antagonistic sets of striated muscles that are driven by a neural network in the stomatogastric ganglion. In vitro, this circuit can spontaneously generate a single (type I) motor program, unlike in vivo in which gastric mill patterns with different phase relationships are found. By using paired intrasomatic recordings, all elements of the gastric mill network, which consists mainly of motoneurons, have been identified and their synaptic relationships established. The gastric mill circuit of Homarus is similar to that of other decapod crustaceans, although some differences in neuron number and synaptic connectivity were found. Moreover, specific members of the lobster network receive input from two identified interneurons, one excitatory and one inhibitory, that project from each rostral commissural ganglion. Integration of input from these projection elements is mediated by synaptic interactions within the gastric mill network itself. In arrhythmic preparations, direct phasic stimulation of the previously identified commissural gastric (CG) interneuron evokes gastric mill output similar to the type I pattern spontaneously expressed in vitro and in vivo. The newly identified gastric inhibitor interneuron makes inhibitory synapses onto a different subset of gastric mill neurons and, when activated with the CG neuron, drives gastric mill output similar to the type II pattern that is only observed in the intact animal. Thus, two distinct phenotypes of gastric mill network activity can be specified by the concerted actions of parallel input pathways and synaptic connectivity within a target central pattern generator. PMID:10212319

  17. Real-time Walking Pattern Generation for a Biped Robot with Hybrid CPG-ZMP Algorithm

    Directory of Open Access Journals (Sweden)

    Bin He

    2014-10-01

    Full Text Available Biped robots have better mobility than conventional wheeled robots. The bio-inspired method based on a central pattern generator (CPG can be used to control biped robot walking in a manner like human beings. However, to achieve stable locomotion, it is difficult to modulate the parameters for the neural networks to coordinate every degree of freedom of the walking robot. The zero moment point (ZMP method is very popular for the stability control of biped robot walking. However, the reference trajectories have low energy efficiency, lack naturalness and need significant offline calculation. This paper presents a new method for biped real-time walking generation using a hybrid CPG-ZMP control algorithm. The method can realize a stable walking pattern by combining the ZMP criterion with rhythmic motion control. The CPG component is designed to generate the desired motion for each robot joint, which is modulated by phase resetting according to foot contact information. By introducing the ZMP location, the activity of the CPG output signal is adjusted to coordinate the limbs’ motion and allow the robot to maintain balance during the process of locomotion. The numerical simulation results show that, compared with the CPG method, the new hybrid CPG-ZMP algorithm can enhance the robustness of the CPG parameters and improve the stability of the robot. In addition, the proposed algorithm is more energy efficient than the ZMP method. The results also demonstrate that the control system can generate an adaptive walking pattern through interactions between the robot, the CPG and the environment.

  18. Anthropogenic soils in central Amazonia: farmers’ practices, agrobiodiversity and land-use patterns

    OpenAIRE

    Braga Junqueira, A.

    2015-01-01

    Keywords: Terra Preta; Amazonian Dark Earths; Shifting cultivation; Homegardens; Intensification; Diversification; Smallholder farming. André Braga Junqueira (2015). Anthropogenic soils in central Amazonia: farmers’ practices, agrobiodiversity and land-use patterns. PhD thesis, Wageningen University, The Netherlands, with summary in English, 163 pp. Rural Amazonia is increasingly experiencing environmental and socio-economic changes that directly affect smallholder farmers, with ...

  19. Centrality and energy dependence of rapidity correlation patterns in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    The centrality and energy dependence of rapidity correlation patterns are studied in Au + Au collisions by using AMPT with string melting, RQMD and UrQMD models. The behaviors of the short-range correlation (SRC) and the long-range correlation (LRC) are presented clearly by two spatial-position dependent correlation patterns. For centrality dependence, UrQMD and RQMD give similar results as those in AMPT, i.e., in most central collisions, the correlation structure is flatter and the correlation range is larger, which indicates a long range rapidity correlation. A long range rapidity correlation showing up in RQMD and UrQMD implies that parton interaction is not the only source of long range rapidity correlations. For energy dependence, AMPT with string melting and RQMD show quite different results. The correlation patterns in RQMD at low collision energies and those in AMPT at high collision energies have similar structures, i.e. a convex curve, while the correlation patterns in RQMD at high collision energies and those in AMPT at low collision energies show flat structures, having no position dependence. Long range rapidity correlation presents itself at high energy and disappears at low energy in RQMD, which also indicates that long range rapidity correlations may come from some trivial effects, rather than the parton interactions. (authors)

  20. Centrality and energy dependence of rapidity correlation patterns in relativistic heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    LE Tian; XU Ming-Mei; WU Yuan-Fang

    2011-01-01

    The centrality and energy dependence of rapidity correlation patterns are studied in Au+Au collisions by using AMPT with string melting,RQMD and UrQMD models.The behaviors of the shortrange correlation(SRC)and the long-range correlation(LRC)are presented clearly by two spatial-position dependent correlation patterns.For centrality dependence.UrQMD and RQMD give similar results as those in AMPT,i.,e., in most central collisions,the correlation structure is flatter and the correlation range is larger,which indicates a long range rapidity correlation.A long range rapidity correlation showing up in RQMD and UrQMD implies that patton interaction is not the only source of long range rapidity correlations.For energy dependence,AMPT with string melting and RQMD show quite different results.The correlation patterns in RQMD at low collision energies and those in AMPT at high collision energies have similar structures,i.e.aconvex curve.while the correlation patterns in RQMD at high collision energies and those in AMPT at low collision energies show fiat structures,having no position dependence.Long range rapidity correlation presents itself at high energy and disappears at low energy in RQMD,which also indicates that long range rapidity correlations may come from some trivial effects,rather than the parton interactions.

  1. Major Dietary Patterns in Relation to General and Central Obesity among Chinese Adults.

    Science.gov (United States)

    Yu, Canqing; Shi, Zumin; Lv, Jun; Du, Huaidong; Qi, Lu; Guo, Yu; Bian, Zheng; Chang, Liang; Tang, Xuefeng; Jiang, Qilian; Mu, Huaiyi; Pan, Dongxia; Chen, Junshi; Chen, Zhengming; Li, Liming

    2015-07-01

    Limited evidence exists for the association between diet pattern and obesity phenotypes among Chinese adults. In the present study, we analyzed the cross-sectional data from 474,192 adults aged 30-79 years from the China Kadoorie Biobank baseline survey. Food consumption was collected by an interviewer-administered questionnaire. Three dietary patterns were extracted by factor analysis combined with cluster analysis. After being adjusted for potential confounders, individuals following a traditional southern dietary pattern had the lowest body mass index (BMI) and waist circumference (WC); the Western/new affluence dietary pattern had the highest BMI; and the traditional northern dietary pattern had the highest WC. Compared to the traditional southern dietary pattern in multivariable adjusted logistic models, individuals following a Western/new affluence dietary pattern had a significantly increased risk of general obesity (prevalence ratio (PR): 1.06, 95% confidence interval (CI): 1.03-1.08) and central obesity (PR: 1.07, 95% CI: 1.06-1.08). The corresponding risks for the traditional northern dietary pattern were 1.05 (1.02-1.09) and 1.17 (1.25-1.18), respectively. In addition, the associations were modified by lifestyle behaviors, and the combined effects with alcohol drinking, tobacco smoking, and physical activity were analyzed. Further prospective studies are needed to elucidate the diet-obesity relationships. PMID:26184308

  2. Major Dietary Patterns in Relation to General and Central Obesity among Chinese Adults

    Directory of Open Access Journals (Sweden)

    Canqing Yu

    2015-07-01

    Full Text Available Limited evidence exists for the association between diet pattern and obesity phenotypes among Chinese adults. In the present study, we analyzed the cross-sectional data from 474,192 adults aged 30–79 years from the China Kadoorie Biobank baseline survey. Food consumption was collected by an interviewer-administered questionnaire. Three dietary patterns were extracted by factor analysis combined with cluster analysis. After being adjusted for potential confounders, individuals following a traditional southern dietary pattern had the lowest body mass index (BMI and waist circumference (WC; the Western/new affluence dietary pattern had the highest BMI; and the traditional northern dietary pattern had the highest WC. Compared to the traditional southern dietary pattern in multivariable adjusted logistic models, individuals following a Western/new affluence dietary pattern had a significantly increased risk of general obesity (prevalence ratio (PR: 1.06, 95% confidence interval (CI: 1.03–1.08 and central obesity (PR: 1.07, 95% CI: 1.06–1.08. The corresponding risks for the traditional northern dietary pattern were 1.05 (1.02–1.09 and 1.17 (1.25–1.18, respectively. In addition, the associations were modified by lifestyle behaviors, and the combined effects with alcohol drinking, tobacco smoking, and physical activity were analyzed. Further prospective studies are needed to elucidate the diet-obesity relationships.

  3. Generation of 1D interference patterns of Bloch surface waves

    Science.gov (United States)

    Kadomina, E. A.; Bezus, E. A.; Doskolovich, L. L.

    2016-09-01

    Interference patterns of Bloch surface waves with a period that is significantly less than the wavelength of incident radiation are formed using dielectric diffraction gratings located on the surface of photonic crystal. The simulation based on electromagnetic diffraction theory is used to demonstrate the possibility of high-quality interference patterns due to resonant enhancement of higher evanescent diffraction orders related to the excitation of the Bloch surface waves. The contrast of the interference patterns is close to unity, and the period is less than the period of the diffraction structure by an order of magnitude.

  4. Dietary patterns are associated with general and central obesity in elderly living in a Brazilian city

    OpenAIRE

    Priscila Lucelia Moreira; Jose Eduardo Corrente; Paulo Jose Fortes Villas Boas; Ana Lucia Anjos Ferreira

    2014-01-01

    Objective: dietary pattern evaluation is often used in order to determine wheter a diet is healthy, as well as to predict the onset of diseases. This study aimed to identify dietary patterns, and to examine their associations with general (body mass index) and central (waist circumference and waist-to-hip ratio) obesity in community-living elderly in a Brazilian city. Methods: this cross-sectional study included 126 elderly subjects aged 60 or older (57.1% females and mean age 74.2 ± 6.46 y...

  5. FORMATION MECHANISM AND SPATIAL PATTERN OF URBAN AGGLOMERATION IN CENTRAL JILIN OF CHINA

    Institute of Scientific and Technical Information of China (English)

    QIN Gan; ZHANG Ping-yu; JIAO Bin

    2006-01-01

    Urban agglomeration is made up of cities with different sizes to be linked by traffic network in a given area, and it is an inevitable result when urbanization reaches a certain level. Taking urban agglomerationin central Jilin(UACJ) as an example, this article analyzes the formation mechanism and spatial pattern of urban agglomeration in the less-developed area. First, the dynamics of UACJ has been analyzed from the aspects of geographical condition, economic foundation, policy background, and traffic condition. Then the development process is divided into three stages-single city, city group and city cluster. Secondly, the central cities are identified from the aspects of city centrality, and the development axes are classified based on economic communication capacity. Finally, the urban agglomeration is divided into five urban economic regions in order to establish the reasonable distribution of industries.

  6. The genotype-phenotype relationship in multicellular pattern-generating models - the neglected role of pattern descriptors

    Directory of Open Access Journals (Sweden)

    Plahte Erik

    2009-09-01

    Full Text Available Abstract Background A deep understanding of what causes the phenotypic variation arising from biological patterning processes, cannot be claimed before we are able to recreate this variation by mathematical models capable of generating genotype-phenotype maps in a causally cohesive way. However, the concept of pattern in a multicellular context implies that what matters is not the state of every single cell, but certain emergent qualities of the total cell aggregate. Thus, in order to set up a genotype-phenotype map in such a spatiotemporal pattern setting one is actually forced to establish new pattern descriptors and derive their relations to parameters of the original model. A pattern descriptor is a variable that describes and quantifies a certain qualitative feature of the pattern, for example the degree to which certain macroscopic structures are present. There is today no general procedure for how to relate a set of patterns and their characteristic features to the functional relationships, parameter values and initial values of an original pattern-generating model. Here we present a new, generic approach for explorative analysis of complex patterning models which focuses on the essential pattern features and their relations to the model parameters. The approach is illustrated on an existing model for Delta-Notch lateral inhibition over a two-dimensional lattice. Results By combining computer simulations according to a succession of statistical experimental designs, computer graphics, automatic image analysis, human sensory descriptive analysis and multivariate data modelling, we derive a pattern descriptor model of those macroscopic, emergent aspects of the patterns that we consider of interest. The pattern descriptor model relates the values of the new, dedicated pattern descriptors to the parameter values of the original model, for example by predicting the parameter values leading to particular patterns, and provides insights that

  7. Generation and Analysis of Constrained Random Sampling Patterns

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas

    2016-01-01

    Random sampling is a technique for signal acquisition which is gaining popularity in practical signal processing systems. Nowadays, event-driven analog-to-digital converters make random sampling feasible in practical applications. A process of random sampling is defined by a sampling pattern, whi...

  8. Object-adapted inverse pattern projection: generation, evaluation, and applications

    Science.gov (United States)

    Bothe, Thorsten; Li, Wansong; von Kopylow, Christoph; Juptner, Werner P.

    2003-05-01

    Fast and robust 3D quality control as well as fast deformation measurement is of particular importance for industrial inspection. Additionally a direct response about measured properties is desired. Therefore, robust optical techniques are needed which use as few images as possible for measurement and visualize results in an efficient way. One promising technique for this aim is the inverse pattern projection which has the following advantages: The technique codes the information of a preceding measurement into the projected inverse pattern. Thus, it is possible to do differential measurements using only one camera frame for each state. Additionally, the results are optimized straight fringes for sampling which are independent of the object curvature. The ability to use any image for inverse projection enables the use for augmented reality, i.e. any properties can be visualized directly on the object's surface which makes inspections easier than with use of a separated indicating device. The hardware needs are low as just a programmable projector and a standard camera are necessary. The basic idea of inverse pattern projection, necessary algorithms ane found optimizations are demonstrated, roughly. Evaluation techniques were found to preserve a high quality phase measurement under imperfect conditions. The different application fields can be sorted out by the type of pattern used for inverse projection. We select two main topics for presentation. One is the incremental (one image per state) deformation measurement which is a promising technique for high speed deformation measurements. A video series of a wavering flag with projected inverse pattern was evaluated to show the complete deformation series. The other application is the optical feature marking (augmented reality) that allows to map any measured result directly onto the object under investigation. The general ability to straighten any kind of information on 3D surfaces is shown while preserving an exact

  9. The Oncoprotein BRD4-NUT Generates Aberrant Histone Modification Patterns

    Science.gov (United States)

    Zee, Barry M.; Dibona, Amy B.; Alekseyenko, Artyom A.; French, Christopher A.; Kuroda, Mitzi I.

    2016-01-01

    Defects in chromatin proteins frequently manifest in diseases. A striking case of a chromatin-centric disease is NUT-midline carcinoma (NMC), which is characterized by expression of NUT as a fusion partner most frequently with BRD4. ChIP-sequencing studies from NMC patients revealed that BRD4-NUT (B4N) covers large genomic regions and elevates transcription within these domains. To investigate how B4N modulates chromatin, we performed affinity purification of B4N when ectopically expressed in 293-TREx cells and quantified the associated histone posttranslational modifications (PTM) using proteomics. We observed significant enrichment of acetylation particularly on H3 K18 and of combinatorial patterns such as H3 K27 acetylation paired with K36 methylation. We postulate that B4N complexes override the preexisting histone code with new PTM patterns that reflect aberrant transcription and that epigenetically modulate the nucleosome environment toward the NMC state. PMID:27698495

  10. 32 nm imprint masks using variable shape beam pattern generators

    Science.gov (United States)

    Selinidis, Kosta; Thompson, Ecron; Schmid, Gerard; Stacey, Nick; Perez, Joseph; Maltabes, John; Resnick, Douglas J.; Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-05-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL ®) is a unique method that has been designed from the beginning to enable precise overlay for creating multilevel devices. A photocurable low viscosity monomer is dispensed dropwise to meet the pattern density requirements of the device, thus enabling imprint patterning with a uniform residual layer across a field and across entire wafers. Further, S-FIL provides sub-100 nm feature resolution without the significant expense of multi-element, high quality projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x templates with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub 32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the template is discussed and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  11. Interactions between zebrafish pigment cells responsible for the generation of Turing patterns

    OpenAIRE

    Nakamasu, Akiko; Takahashi, Go; Kanbe, Akio; KONDO, Shigeru

    2009-01-01

    The reaction–diffusion system is one of the most studied nonlinear mechanisms that generate spatially periodic structures autonomous. On the basis of many mathematical studies using computer simulations, it is assumed that animal skin patterns are the most typical examples of the Turing pattern (stationary periodic pattern produced by the reaction–diffusion system). However, the mechanism underlying pattern formation remains unknown because the molecular or cellular basis of the phenomenon ha...

  12. EXPRESSION PATTERNS OF ESTROGEN RECEPTORS IN THE CENTRAL AUDITORY SYSTEM CHANGE IN PREPUBERTAL AND AGED MICE

    Science.gov (United States)

    Charitidi, K.; Frisina, R. D.; Vasilyeva, O. N.; Zhu, X.; Canlon, B.

    2011-01-01

    Estrogens are important in the development, maintenance and physiology of the CNS. Several studies have shown their effects on the processing of hearing in both males and females, and these effects, in part, are thought to result from regulation of the transcription of genes via their classical estrogen receptor (ER) pathway. In order to understand the spatiotemporal changes that occur with age, we have studied the expression of ERs in the central auditory pathway in prepubertal and aged CBA mice with immunohistochemistry. In prepubertal mice a clear dichotomy was noted between the expression of ERα and ERβ. ERβ-positive neurons were found in the metencephalon whereas the majority of ERα was found in mesencephalon, diencephalon or the telencephalon. In the aged animals a different pattern of ER expression was found in terms of location and overall intensity. These age-induced changes in the expression pattern were generally not uniform, suggesting that region-specific mechanisms regulate the ERs’ age-related expression. Neither the prepubertal nor the aged animals showed sex differences in any auditory structure. Our results demonstrate different age-dependent spatial and temporal changes in the pattern of expression of ERα and ERβ, suggesting that each ER type may be involved in distinct roles across the central auditory pathway in different periods of maturation. PMID:20736049

  13. GENERATING FRACTAL PATTERNS BY USING p-CIRCLE INVERSION

    Science.gov (United States)

    Ramírez, José L.; Rubiano, Gustavo N.; Zlobec, Borut Jurčič

    2015-10-01

    In this paper, we introduce the p-circle inversion which generalizes the classical inversion with respect to a circle (p = 2) and the taxicab inversion (p = 1). We study some basic properties and we also show the inversive images of some basic curves. We apply this new transformation to well-known fractals such as Sierpinski triangle, Koch curve, dragon curve, Fibonacci fractal, among others. Then we obtain new fractal patterns. Moreover, we generalize the method called circle inversion fractal be means of the p-circle inversion.

  14. PATTERN OF CUTANEOUS DISEASES IN INMATES OF CENTRAL JAIL, LUDHIANA, PUNJAB

    Directory of Open Access Journals (Sweden)

    Bimal

    2014-04-01

    Full Text Available BACKGROUND: Prisons are fertile breeding places for many skin infections and infestations; also the prevalent stressful conditions may aggravate preexisting skin problems. OBJECTIVES: To determine the pattern of cutaneous diseases in Central Jail, Ludhiana, Punjab (male prison. MATERIALS AND METHODS: The jail inmates were examined as a part of special skin camp organized in the Central Jail Ludhiana by the dermatologist after eliciting a brief history. RESULTS: Of the 157 patients examined, 70% were infectious; commonest being scabies followed by pyodermas, dermatophytosis, pityriasis versicolor, warts. Eczemas and Acne vulgaris were the most common non-infectious conditions seen. CONCLUSIONS: We recommend screening of new inmates by a dermatologist and periodic skin camps to be conducted in prisons at regular intervals.

  15. Produc—Oriented Test—Pattern Generation for Programmable Logic Arrays

    Institute of Scientific and Technical Information of China (English)

    李锦涛; 闵应骅

    1990-01-01

    A Product-oriented test-pattern generation strategy for Programmable Logic Arrays(PLAs) is presented.First the personality of products is discussed.Products are divided into several categories to speed up the test generation.This strategy aims at generating a very compact test set for crosspoint defects through the folllowing steps:1)generate special test vectors for each category of products at the beginning of test generation.Each vector is capable of detecting a great amount of crosspoint defects;2)generate test vectors for the defects which are not covered by the tests already generated.In this step,some heuristics are employed to accelerate test generation.Based on this strategy,a PLA test-pattern generation system is developed and the experimental results are analyzed.

  16. Morphodynamics and anabranching patterns generated in the Madeira River, Brazil

    Science.gov (United States)

    Latrubesse, E. M.; Bonthius, C.; Abad, J. D.; Stevaux, J.; Filizola, N.; Frias, C. E.

    2013-12-01

    The Madeira River is the largest tributary in water discharge and sediment transport of the Amazon River. At present, this river is at the center of a controversial political discussion because the Brazilian government is building two hydroelectric plants on the Bolivia-Brazil border, flooding a long reach from near Cachuela Esperanza in the tributary Beni River, close to the Brazil-Bolivia border, up to Porto Velho. We present results from three field expeditions carried out in July-August 2011, December 2012 and March 2013. The main scope of this article is to disseminate the environmental threat suffered by the Madeira from regulation/disruption, and to present preliminary results on the geomorphologic characteristics of the Madeira channel and floodplain. Using historical radar and satellite imagery, the floodplain morpho-sedimentary units and morphology of the channel were assessed and quantified. Sediment bed and bank sampling, bathymetric surveys and velocity measurements were recorded using a single beam echo sounder and an acoustic Doppler current profiler (ADCP), respectively. Velocity data were analyzed using TRDI's WinRiverII and a MATLAB-based software package Velocity Mapping Tool. We consider that the Madeira River offers some ideal conditions to provide information on critical conditions and geomorphologic thresholds in mega-rivers. The Madeira River has been classified as a simple to moderate anabranching low-sinuosity river. The Madeira flows through a relatively simple pattern, alternating straight reaches with others that exhibit an incipient tendency to anabranch. Single beam and ADCP data yields insight into the bathymetry and flow characteristics in the channel through straight, pseudo-meandering, and anabranching stretches. We studied in detail three selected three reaches zones where three primary mechanisms for anabranching were identified: a) branches upstream and downstream in box shape pseudo-meanders; b) simple branch patterns

  17. From social behavior to neural circuitry: steroid hormones rapidly modulate advertisement calling via a vocal pattern generator.

    Science.gov (United States)

    Remage-Healey, Luke; Bass, Andrew H

    2006-09-01

    Across vertebrates, androgens are rapidly elevated within minutes in response to aggressive or reproductive stimuli, yet it is unclear what the causal relationship is between fast androgen elevation and the ongoing (minute-by-minute) expression of behavior. This study tested the hypothesis that rapid increases in plasma steroid levels induce similarly rapid increases in both vocal behavior and the neurophysiological output of a central pattern generator that governs vocal behavior. In Gulf toadfish (Opsanus beta), males call to attract females to their nesting sites, and both males and females vocalize in aggressive interactions. Previous field experiments with males showed that simulated territorial challenges produce rapid and concurrent elevations in ongoing calling behavior and circulating levels of the teleost-specific androgen 11-ketotestosterone (11kT), but not the glucocorticoid cortisol. The current field experiments showed that non-invasive (food) delivery of 11kT, but not cortisol, induced an elevation within 10 min in the ongoing calling behavior of males. Electrophysiological experiments revealed that intramuscular injections of either 11kT or cortisol, but neither testosterone nor 17-beta-estradiol, induced increases within 5 min in the output of the vocal pattern generator in males, whereas only cortisol had similarly fast effects in females. The field behavioral results support predictions generated by the challenge hypothesis and also parallel the 11kT-dependent modulation of the vocal pattern generator in males. The cortisol effect on the vocal pattern generator in both sexes predicts that glucocorticoids regulate vocalizations in non-advertisement contexts. Together, these experiments provide strong support for the hypothesis that surges in circulating steroid levels play a causal role in shaping rapid changes in social behavior (vocalizations) through non-genomic-like actions on neural (vocal motor) circuits that directly encode behavioral

  18. Directivity patterns of laser-generated sound in solids: Effects of optical and thermal parameters

    CERN Document Server

    Krylov, Victor V

    2014-01-01

    In the present paper, directivity patterns of laser-generated sound in solids are investigated theoretically. Two main approaches to the calculation of directivity patterns of laser-generated sound are discussed for the most important case of thermo-optical regime of generation. The first approach, which is widely used in practice, is based on the simple modelling of the equivalent thermo-optical source as a mechanical dipole comprising two horizontal forces applied to the surface in opposite directions. The second approach is based on the rigorous theory that takes into account all acoustical, optical and thermal parameters of a solid material and all geometrical and physical parameters of a laser beam. Directivity patterns of laser-generated bulk longitudinal and shear elastic waves, as well as the amplitudes of generated Rayleigh surface waves, are calculated for different values of physical and geometrical parameters and compared with the directivity patterns calculated in case of dipole-source representa...

  19. Fluid power network for centralized electricity generation in offshore wind farms

    NARCIS (Netherlands)

    Jarquin-Laguna, A.

    2014-01-01

    An innovative and completely different wind-energy conversion system is studied where a centralized electricity generation within a wind farm is proposed by means of a hydraulic network. This paper presents the dynamic interaction of two turbines when they are coupled to the same hydraulic network.

  20. Investigation of the role of large-scale circulation patterns on Central European streamflow

    Science.gov (United States)

    Steirou, Eva; Apel, Heiko; Merz, Bruno

    2016-04-01

    Large scale oscillations-phenomena such as El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) influence the climate and hydrological variables (temperature, precipitation, streamflow) in many areas around the globe. Here we review previous studies examining links between such phenomena and streamflow in Central Europe. The selected area under examination is the region covered by 9 countries: Germany, Poland, Switzerland, Lichtenstein, Austria, the Czech Republic, Slovakia, Hungary and Slovenia. The study takes into consideration only measured and not proxy data. Mean, low and high flows are examined separately in order to improve the understanding on the possible different influences of the climatic phenomena on different streamflow characteristics. Previous results form a consistent pattern that suggests causal relationships but only for certain indices and seasons. Most promising results concern the winter NAO index which seems to affect winter and spring streamflow in Central Europe and synoptic circulation patterns that have been linked to streamflow in the area throughout the year. Based on the findings of the review, we examine further the relations between NAO, synoptic circulation patterns and streamflow in the winter and spring season. In our analysis we examine 68 streamflow stations in Germany all covering the period 1932 to 2005. The investigation focuses on the interplay between NAO and synoptic patterns and on the effects of the climatic indices on the amplitude, spatial coherence and distributions of streamflow data. The preliminary results suggest that NAO weakly influences streamflow in both seasons and that a combined analysis with other climatic parameters may clarify possible existing links.

  1. Computer-Assisted Generation of Patterns and Virtual Reality Techniques for Fashion Design

    Science.gov (United States)

    Naud, Mickael; Richard, Paul; Chapeau-Blondeau, François

    2009-03-01

    We present a methodology for the design of aesthetic patterns and their visualization on virtual clothes. Generated patterns are directly mapped on the dress of a virtual mannequin. Furthermore, patterns sets may be interactively mapped on the virtual dress using a specific 3D interaction technique called Back-and-Forth. Pattern generation involves different mathematical approaches such as iterated function systems (IFS) and nonlinear trajectory models. Both model parameters and color space exploration is performed through a simple user interface. This work contributes to promote both computer assistance in the context of mass customization for fashion design.

  2. Interference pattern generation and simulation in the single beam of a white light continuum

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We demonstrate the interference phenomenon in the White Light Continuum(WLC) generated by a single femtosecond laser beam. Different kinds of spatial interference patterns of the WLC generation under various conditions were investigated. The spatial patterns were attributed to interference between the filaments in the WLC generated by the fundamental laser beam yielding the diffraction effect from spatial confinement. Simulations of different patterns were performed. By comparing the results of simulation with those of experiments,the distances of several micrometers between the neighboring filaments can be derived,which agree with the literature values from direct measurements.

  3. Arctic geese during brood-rearing on the central Yukon-Kuskokwim Delta: Analysis of patterns of distribution: Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In July 1985 two systematic aerial surveys were flown over the coastal fringe of the central Yukon-Kuskokwim Delta, Alaska, to examine the patterns of distribution...

  4. Using Unique-Prime-Factorization Theorem to Mine Frequent Patterns without Generating Tree

    Directory of Open Access Journals (Sweden)

    Hossein Tohidi

    2011-01-01

    Full Text Available Problem statement: Ffrequent patterns are patterns that appear in a data set frequently. Finding such frequent patterns plays an essential role in mining associations, correlations and many other interesting relationships among data. Approach: Most of the previous studies adopt an Apriorilike approach. For huge database it may need to generate a huge number of candidate sets. An interest solution is to design an approach that without generating candidate is able to mine frequent patterns. Results: An interesting method to frequent pattern mining without generating candidate pattern is called frequent-pattern growth, or simply FP-growth, which adopts a divide-and-conquer strategy as follows. However, for a large database, constructing a large tree in the memory is a time consuming task and increase the time of execution. In this study we introduce an algorithm to generate frequent patterns without generating a tree and therefore improve the time complexity and memory complexity as well. Our algorithm works based on prime factorization and is called Prime Factor Miner (PFM. Conclusion/Recommendations: This algorithm is able to achieve low memory order at O(1 which is significantly better than FP-growth.

  5. Pattern of Maxillofacial fracture in Western and Central Nepal: An experience in 3 tertiary level health institutions

    OpenAIRE

    S. Subedi; Shrestha, B; RB Adhikari

    2015-01-01

    BACKGROUND: There are only few studies regarding the pattern and causes of maxillofacial fractures till date in Nepal and no such study in western and central Nepalese population has been conducted. The purpose of this study, therefore, was to describe the causes and the pattern of maxillofacial fractures in western and central part of Nepal over the period of 5 years. MATERIAL AND METHODS A retrospective analysis of maxillofacial fractures was conducted on 328 patients who were treated in ...

  6. The Spalt Transcription Factors Generate the Transcriptional Landscape of the Drosophila melanogaster Wing Pouch Central Region

    OpenAIRE

    Organista, María F.; Mercedes Martín; de Celis, Jesus M.; Rosa Barrio; Ana López-Varea; Nuria Esteban; Mar Casado; Celis, Jose F. de

    2015-01-01

    The Drosophila genes spalt major (salm) and spalt-related (salr) encode Zn-finger transcription factors regulated by the Decapentaplegic (Dpp) signalling pathway in the wing imaginal disc. The function of these genes is required for cell survival and proliferation in the central region of the wing disc, and also for vein patterning in the lateral regions. The identification of direct Salm and Salr target genes, and the analysis of their functions, are critical steps towards understanding the ...

  7. Strain patterns along the Kaparelli–Asopos rift (central Greece from campaign GPS data

    Directory of Open Access Journals (Sweden)

    Aggeliki Marinou

    2015-06-01

    Full Text Available We present results from four GPS campaigns in the broader Kaparelli–Asopos area in central Greece. This area is undergoing extension as demonstrated by seismological, geodetic and geological data. The east-west striking Kaparelli normal fault ruptured during the March 4, 1981, M = 6.3 earthquake and created km-long surface breaks with the downthrown side to the south. The geodetic results include: determination of station coordinates in the ITRF 2005 frame, computation of station velocities with respect to stable Europe and strain rate tensor estimates. The pattern of velocities along the east-west direction (parallel to the rift axis; 40 km E-W × 12 km N-S and azimuth of strain axes are compared to geological data and to other GPS results in central Greece. We find that strain in this region consists of an amount of shortening (66 ns/yr in the direction approximately N 58°E, and about three times more extension (187 ns/yr at N 32°W. A large change in strain orientation (from NW to NNE is observed from west to east, along the active faults of Asopos rift in agreement with fault slip data. This change signifies the need for using local GPS networks to map local strain rate patterns in actively extending regions of Greece.

  8. Generative Models of Segregation: Investigating Model-Generated Patterns of Residential Segregation by Ethnicity and Socioeconomic Status

    OpenAIRE

    Fossett, Mark

    2011-01-01

    This paper considers the potential for using agent models to explore theories of residential segregation in urban areas. Results of generative experiments conducted using an agent-based simulation of segregation dynamics document that varying a small number of model parameters representing constructs from urban-ecological theories of segregation can generate a wide range of qualitatively distinct and substantively interesting segregation patterns. The results suggest how complex, macro-level ...

  9. Plate tectonics and biogeographical patterns of the Pseudophoxinus (Pisces: Cypriniformes) species complex of central Anatolia, Turkey.

    Science.gov (United States)

    Hrbek, Tomas; Stölting, Kai N; Bardakci, Fevzi; Küçük, Fahrettin; Wildekamp, Rudolf H; Meyer, Axel

    2004-07-01

    We investigated the phylogenetic relationships of Pseudophoxinus (Cyprinidae: Leuciscinae) species from central Anatolia, Turkey to test the hypothesis of geographic speciation driven by early Pliocene orogenic events. We analyzed 1141 aligned base pairs of the complete cytochrome b mitochondrial gene. Phylogenetic relationships reconstructed by maximum likelihood, Bayesian likelihood, and maximum parsimony methods are identical, and generally well supported. Species and clades are restricted to geologically well-defined units, and are deeply divergent from each other. The basal diversification of central Anatolian Pseudophoxinus is estimated to have occurred approximately 15 million years ago. Our results are in agreement with a previous study of the Anatolian fish genus Aphanius that also shows a diversification pattern driven by the Pliocene orogenic events. The distribution of clades of Aphanius and Pseudophoxinus overlap, and areas of distribution comprise the same geological units. The geological history of Anatolia is likely to have had a major impact on the diversification history of many taxa occupying central Anatolia; many of these taxa are likely to be still unrecognized as distinct.

  10. Comparison of large central and small decentralized power generation in India

    Energy Technology Data Exchange (ETDEWEB)

    None

    1997-05-01

    This reports evaluates two options for providing reliable power to rural areas in India. The benefits and costs are compared for biomass based distributed generation (DG) systems versus a 1200-MW central grid coal-fired power plant. The biomass based DG systems are examined both as alternatives to grid extension and as supplements to central grid power. The benefits are divided into three categories: those associated with providing reliable power from any source, those associated specifically with biomass based DG technology, and benefits of a central grid coal plant. The report compares the estimated delivered costs of electricity from the DG systems to those of the central plant. The analysis includes estimates for a central grid coal plant and four potential DG system technologies: Stirling engines, direct-fired combustion turbines, fuel cells, and biomass integrated gasification combined cycles. The report also discusses issues affecting India`s rural electricity demand, including economic development, power reliability, and environmental concerns. The results of the costs of electricity comparison between the biomass DG systems and the coal-fired central grid station demonstrated that the DG technologies may be able to produce very competitively priced electricity by the start of the next century. The use of DG technology may provide a practical means of addressing many rural electricity issues that India will face in the future. Biomass DG technologies in particular offer unique advantages for the environment and for economic development that will make them especially attractive. 58 refs., 31 figs.

  11. Comparison of large central and small decentralized power generation in India

    International Nuclear Information System (INIS)

    This reports evaluates two options for providing reliable power to rural areas in India. The benefits and costs are compared for biomass based distributed generation (DG) systems versus a 1200-MW central grid coal-fired power plant. The biomass based DG systems are examined both as alternatives to grid extension and as supplements to central grid power. The benefits are divided into three categories: those associated with providing reliable power from any source, those associated specifically with biomass based DG technology, and benefits of a central grid coal plant. The report compares the estimated delivered costs of electricity from the DG systems to those of the central plant. The analysis includes estimates for a central grid coal plant and four potential DG system technologies: Stirling engines, direct-fired combustion turbines, fuel cells, and biomass integrated gasification combined cycles. The report also discusses issues affecting India's rural electricity demand, including economic development, power reliability, and environmental concerns. The results of the costs of electricity comparison between the biomass DG systems and the coal-fired central grid station demonstrated that the DG technologies may be able to produce very competitively priced electricity by the start of the next century. The use of DG technology may provide a practical means of addressing many rural electricity issues that India will face in the future. Biomass DG technologies in particular offer unique advantages for the environment and for economic development that will make them especially attractive. 58 refs., 31 figs

  12. The Lycaenid Central Symmetry System: Color Pattern Analysis of the Pale Grass Blue Butterfly Zizeeria maha.

    Science.gov (United States)

    Iwata, Masaki; Taira, Wataru; Hiyama, Atsuki; Otaki, Joji M

    2015-06-01

    The nymphalid groundplan has been proposed to explain diverse butterfly wing color patterns. In this model, each symmetry system is composed of a core element and a pair of paracore elements. The development of this elemental configuration has been explained by the induction model for positional information. However, the diversity of color patterns in other butterfly families in relation to the nymphalid groundplan has not been thoroughly examined. Here, we examined aberrant color pattern phenotypes of a lycaenid butterfly, Zizeeria maha, from mutagenesis and plasticity studies as well as from field surveys. In several mutants, the third and fourth spot arrays were coordinately positioned much closer to the discal spot in comparison to the normal phenotype. In temperature-shock types, the third and fourth array spots were elongated inwardly or outwardly from their normal positions. In field-caught spontaneous mutants, small black spots were located adjacent to normal black spots. Analysis of these aberrant phenotypes indicated that the spots belonging to the third and fourth arrays are synchronously changeable in position and shape around the discal spot. Thus, these arrays constitute paracore elements of the central symmetry system of the lycaenid butterflies, and the discal spot comprises the core element. These aberrant phenotypes can be explained by the black-inducing signals that propagate from the prospective discal spot, as predicted by the induction model. These results suggest the existence of long-range developmental signals that cover a large area of a wing not only in nymphalid butterflies, but also in lycaenid butterflies.

  13. Dual CARS and SHG image acquisition scheme that combines single central fiber and multimode fiber bundle to collect and differentiate backward and forward generated photons.

    Science.gov (United States)

    Weng, Sheng; Chen, Xu; Xu, Xiaoyun; Wong, Kelvin K; Wong, Stephen T C

    2016-06-01

    In coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) imaging, backward and forward generated photons exhibit different image patterns and thus capture salient intrinsic information of tissues from different perspectives. However, they are often mixed in collection using traditional image acquisition methods and thus are hard to interpret. We developed a multimodal scheme using a single central fiber and multimode fiber bundle to simultaneously collect and differentiate images formed by these two types of photons and evaluated the scheme in an endomicroscopy prototype. The ratio of these photons collected was calculated for the characterization of tissue regions with strong or weak epi-photon generation while different image patterns of these photons at different tissue depths were revealed. This scheme provides a new approach to extract and integrate information captured by backward and forward generated photons in dual CARS/SHG imaging synergistically for biomedical applications.

  14. Electric generator overhaul of the Ing. Carlos Ramirez Ulloa hydroelectric. Central project conclusions; Rehabilitacion de los generadores de la central hidroelectrica Ing. Carlos Ramirez Ulloa. Conclusiones del proyecto

    Energy Technology Data Exchange (ETDEWEB)

    Campuzano Martinez, Ignacio Roberto; Gonzalez Vazquez, Alejandro Esteban; Robles Pimentel, Edgar Guillermo; Esparza Saucedo, Marcos; Garcia Martinez, Javier; Sanchez Flores, Ernesto; Martinez Romero, Jose Luis [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The Hydroelectric Ing. Carlos Ramirez Ulloa Power Central has three 200 MW electric generators. The Central initiated its commercial operation in 1985. The electric generators had design problems that were properly corrected in an overhaul program that was initiated in 1996, with Unit 2 electric generator and completed in 1998 with Unit 1 electric generator. This paper presents the relevant aspects of the experience accumulated in the project. [Espanol] La central hidroelectrica Ing. Carlos Ramirez Ulloa cuenta con tres generadores de 200 MW cada uno. La central inicio su operacion comercial en 1985. Los generadores tenian problemas de diseno que fueron debidamente corregidos en un programa de rehabilitacion que inicio en 1996, con el generador de la unidad 2, y culmino en 1998 con el generador de la unidad 1. En este articulo se presentan los aspectos relevantes de la experiencia acumulada en el proyecto.

  15. Interactions between zebrafish pigment cells responsible for the generation of Turing patterns.

    Science.gov (United States)

    Nakamasu, Akiko; Takahashi, Go; Kanbe, Akio; Kondo, Shigeru

    2009-05-26

    The reaction-diffusion system is one of the most studied nonlinear mechanisms that generate spatially periodic structures autonomous. On the basis of many mathematical studies using computer simulations, it is assumed that animal skin patterns are the most typical examples of the Turing pattern (stationary periodic pattern produced by the reaction-diffusion system). However, the mechanism underlying pattern formation remains unknown because the molecular or cellular basis of the phenomenon has yet to be identified. In this study, we identified the interaction network between the pigment cells of zebrafish, and showed that this interaction network possesses the properties necessary to form the Turing pattern. When the pigment cells in a restricted region were killed with laser treatment, new pigment cells developed to regenerate the striped pattern. We also found that the development and survival of the cells were influenced by the positioning of the surrounding cells. When melanophores and xanthophores were located at adjacent positions, these cells excluded one another. However, melanophores required a mass of xanthophores distributed in a more distant region for both differentiation and survival. Interestingly, the local effect of these cells is opposite to that of their effects long range. This relationship satisfies the necessary conditions required for stable pattern formation in the reaction-diffusion model. Simulation calculations for the deduced network generated wild-type pigment patterns as well as other mutant patterns. Our findings here allow further investigation of Turing pattern formation within the context of cell biology. PMID:19433782

  16. Hybrid centralized-distributed power conditioning system for thermoelectric generator with high energy efficiency

    DEFF Research Database (Denmark)

    Wu, Hongfei; Sun, Kai; Chen, Min;

    2013-01-01

    The unbalanced temperature distribution influences the power output of thermoelectric generator (TEG) system, which leads to mismatch power among TEG modules. This mismatch power degrades the energy efficiency of TEG systems based on the series-connected TEG modules. A hybrid centralized-distribu......The unbalanced temperature distribution influences the power output of thermoelectric generator (TEG) system, which leads to mismatch power among TEG modules. This mismatch power degrades the energy efficiency of TEG systems based on the series-connected TEG modules. A hybrid centralized...... the proposed system, which benefits for implementing high MPPT efficiency and high conversion efficiency simultaneously. A hybrid MPPT control strategy is proposed for this HCD power conditioning system. The characteristics, circuit implementation and operation principles of the proposed system are presented...

  17. Generating power stations and optimization energetic of processes; Centrales generadoras y optimacion energetica de procesos

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Ramirez, Ranulfo; Fernandez Montiel, Manuel Francisco [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    Some recent experiences of the Management of Thermal Processes of the Instituto de Investigaciones Electricas (IIE) related to the works on generating power stations of electricity, plants of cogeneration and energy saving are presented. [Spanish] Se presentan algunas experiencias recientes de la Gerencia de Procesos Termicos del Instituto de Investigaciones Electricas (IIE) relacionadas con los trabajos sobre centrales generadoras de electricidad, plantas de cogeneracion y ahorro de energia.

  18. Marine litter in Mediterranean sandy littorals: Spatial distribution patterns along central Italy coastal dunes.

    Science.gov (United States)

    Poeta, Gianluca; Battisti, Corrado; Acosta, Alicia T R

    2014-12-15

    Sandy shores are generally considered important sinks for marine litter and the presence of this litter may represent a serious threat to biotic communities and dune integrity mostly due to cleaning activities carried out through mechanical equipment. In spring (April-May) 2012 we sampled 153 2×2m random plots to assess the spatial distribution patterns of litter on Central Italy sandy shores. We analysed the relationship between the presence of litter and coastal dune habitats along the sea-inland gradient. Our results showed that the most frequent litter items were plastic and polystyrene. Differences of marine litter spatial distribution were found between upper beach and fore dune habitats and fixed dune habitats: embryo dune and mobile dune habitats show the highest frequency of litter, but, surprisingly, marine litter did not impact fixed dune habitats, these possibly acting as a natural barrier protecting the inner part of the coast from marine litter dispersion. PMID:25455823

  19. Regional differences in health, diet and weaning patterns amongst the first Neolithic farmers of central Europe.

    Science.gov (United States)

    Ash, Abigail; Francken, Michael; Pap, Ildikó; Tvrdý, Zdeněk; Wahl, Joachim; Pinhasi, Ron

    2016-01-01

    Across much of central Europe, the Linearbandkeramik (LBK) represents the first Neolithic communities. Arising in Transdanubia around 5500 cal. BC the LBK spread west to the Rhine within two to three hundred years, carrying elements of a mixed agricultural economy and a relatively homogeneous material culture. Colonisation of new regions during this progress would have required economic adaptations to varied ecological conditions within the landscape. This paper investigates whether such adaptation at a local scale affected health patterns and altered the dietary habits of populations that otherwise shared a common cultural and biological origin. Analysis of non-specific stress (linear enamel hypoplasia, porotic hyperostosis, cribra orbitalia) within five LBK populations from across central Europe in conjunction with published carbon and nitrogen stable isotope data from each site revealed a high prevalence of porotic hyperostosis and cribra orbitalia in western populations that was associated with a lower animal protein intake. Hypoplastic enamel was more frequently observed in eastern populations however, and may reflect geographic differences in childhood morbidity and mortality as a result of variation in social practices relating to weaning. Local socio-economic adaptations within the LBK were therefore an important factor in the exposure of populations to non-specific stress. PMID:27385276

  20. On-Shore Central Hydraulic Power Generation for Wind and Tidal Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lim, Steven; Murray, Luke; Armstrong, Richard; Kimbrall, Richard; Cook-Chenault, Kimberly; DeGennaro, Sean

    2012-01-01

    Tidal energy, offshore wind energy, and onshore wind energy can be converted to electricity at a central ground location by means of converting their respective energies into high-pressure hydraulic flows that are transmitted to a system of generators by high-pressure pipelines. The high-pressure flows are then efficiently converted to electricity by a central power plant, and the low-pressure outlet flow is returned. The Department of Energy (DOE) is presently supporting a project led by Sunlight Photonics to demonstrate a 15 kW tidal hydraulic power generation system in the laboratory and possibly later submerged in the ocean. All gears and submerged electronics are completely eliminated. A second portion of this DOE project involves sizing and costing a 15 MW tidal energy system for a commercial tidal energy plant. For this task, Atlantis Resources Corporation s 18-m diameter demonstrated tidal blades are rated to operate in a nominal 2.6 m/sec tidal flow to produce approximately one MW per set of tidal blades. Fifteen units would be submerged in a deep tidal area, such as in Maine s Western Passage. All would be connected to a high-pressure (20 MPa, 2900 psi) line that is 35 cm ID. The high-pressure HEPG fluid flow is transported 500-m to on-shore hydraulic generators. HEPG is an environmentally-friendly, biodegradable, watermiscible fluid. Hydraulic adaptations to ORPC s cross-flow turbines are also discussed. For 15 MW of wind energy that is onshore or offshore, a gearless, high efficiency, radial piston pump can replace each set of top-mounted gear-generators. The fluid is then pumped to a central, easily serviceable generator location. Total hydraulic/electrical efficiency is 0.81 at full rated wind or tidal velocities and increases to 0.86 at 1/3 rated velocities.

  1. Structural pattern and ascent model in the Central Extremadura batholith, Hercynian belt, Spain

    Science.gov (United States)

    Castro, Antonio

    The Central Extremadura batholith constitutes an important alignment of plutonic rocks occupying part of the internal zones of the Iberian Hercynian belt. It comprises 13 plutons and numerous minor intrusions, and covers a wide compositional range from quartz-diorites to alkali-feldspar granites. Structural study of the individual plutons reveals that their internal structural patterns may be correlated. Correlation between the different structural patterns in the plutons and interpretation of the superimposed deformation in the metasedimentary host rocks indicate that the plutons were emplaced and deformed in an E-W, dextral, intracontinental shear zone developed during the second deformation phase (302-320 Ma). A qualitative ascent model has been established as follows: (1) development of extensional fractures at 45° to the E-W, dextral, shear zone; (2) intrusion of granitic magmas along these fractures and (3) rotation of the earlier intrusions, in a dextral sense, inducing antithetic shear zones (N-S sinistral) and a transverse shortening, perpendicular to the major axis of the earlier, deformed plutons as well as the forced emplacement of the later plutons.

  2. Spatial pattern analysis for quantification of landscape structure of Tadoba-Andhari Tiger Reserve, Central India

    Institute of Scientific and Technical Information of China (English)

    Ambica Paliwal; Vinod Bihari Mathur

    2014-01-01

    Landscape structure is often regarded as an important factor that governs the distribution and abundance of species. Therefore it is critical to understand the landscapes and their dynamics. Patterns of landscape elements strongly influence the ecological characteristics. This study was designed to document and map the current status of the tropi-cal dry deciduous forest of the Tadoba-Andhari Tiger Reserve (TATR), Central India, (using IRS P6 LISS IV data) and to describe its landscape structure at three levels of organization viz. landscape, class, and patch. The study area was classified into 10 land cover classes that include 6 vegetation classes. The landscape structure was analyzed using FRAG-STATS using 12 set of indices. The TATR landscapes have a total of 2,307 patches with a mean patch size of 25.67 ha and patch density of 1.7 patches per km². Amongst all land cover classes, mixed bamboo forest is dominant-it occupied maximum area (77.99%)-while riparian forest is least represented (0.32%). Mixed forest has maximum number of patches among all vegetation classes. Results have shown that despite being dominant in the area, mixed bamboo forest has low patch density (0.25/100 ha). Dominance of mixed bamboo forest is attributed to large patch sizes and not to the number of patches. This study has focussed on the approach of integrating satellite forest classification and forest inven-tory data for studying forest landscape patterns.

  3. Plant diversity-productivity patterns in the alpine steppe environment of the Central Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The biodiversity-productivity relationship is an important topic in the research of bio- diversity and ecosystem function. The plant diversity-productivity pattern is commonly unimodal and positively correlated. This paper researches the characteristics of plant diversity-productivity patterns in the Bayanbuluk alpine steppe in the central Tianshan Mountains, Xinjiang, China, and analyzes the effects of environmental factors on the distribution of plant communities, species composition, plant diversity and productivity in the steppe. The results show a positive correlation between plant diversity and productivity. DCCA (detrended canonical correspondence analysis) ordination reveals a significant relationship between the effects of air temperature, soil moisture content, available soil nitrogen, relative humidity and pH value on the distribution and composition of plant communities. There are significant correlations between the soil moisture content, relative humidity, pH value, air temperature and species richness and the aboveground biomass of Gramineae and Cyperaceae, and also significant correlations between the relative humidity, pH values and the total aboveground biomass of plant communities.

  4. Large-Area Protein Patterns Generated by Ordered Binary Colloidal Assemblies as Templates

    DEFF Research Database (Denmark)

    Singh, Gurvinder; Gohri, Vipul; Pillai, Saju;

    2011-01-01

    .10 to 0.50. This allows masks with variable morphology and thus production of chemical patterns of tunable geometry. Finally, the Au or SiO(2) regions of the pattern are surface modified with protein resistant oligoethyleneglycol self-assembled molecules, which facilitates site selective adsorption......We demonstrate the use of binary colloidal assemblies as lithographic masks to generate tunable Au patterns on SiO(2) substrates with dimensions ranging from micrometers to nanometers. Such patterns can be modified with different chemistries to create patterns with well-defined sites for selective...... adsorption of proteins, where the pattern size and spacing is adjustable depending on particle choice. In our system, the binary colloidal assemblies contain large and small particles of similar or different material and are self-assembled from dilute dispersions with particle size ratios ranging from 0...

  5. Pigment cell movement is not required for generation of Turing patterns in zebrafish skin

    Science.gov (United States)

    Bullara, D.; De Decker, Y.

    2015-01-01

    The zebrafish is a model organism for pattern formation in vertebrates. Understanding what drives the formation of its coloured skin motifs could reveal pivotal to comprehend the mechanisms behind morphogenesis. The motifs look and behave like reaction–diffusion Turing patterns, but the nature of the underlying physico-chemical processes is very different, and the origin of the patterns is still unclear. Here we propose a minimal model for such pattern formation based on a regulatory mechanism deduced from experimental observations. This model is able to produce patterns with intrinsic wavelength, closely resembling the experimental ones. We mathematically prove that their origin is a Turing bifurcation occurring despite the absence of cell motion, through an effect that we call differential growth. This mechanism is qualitatively different from the reaction–diffusion originally proposed by Turing, although they both generate the short-range activation and the long-range inhibition required to form Turing patterns. PMID:25959141

  6. Patterns in volatile organic compound emissions along a savanna-rainforest gradient in central Africa

    Science.gov (United States)

    Klinger, L. F.; Greenburg, J.; Guenther, A.; Tyndall, G.; Zimmerman, P.; M'bangui, M.; Moutsamboté, J.-M.; Kenfack, D.

    1998-01-01

    In temperate regions the chemistry of the lower troposphere is known to be significantly affected by biogenic volatile organic compounds (VOCs) emitted by plants. The chemistry of the lower troposphere over the tropics, however, is poorly understood, in part because of the considerable uncertainties in VOC emissions from tropical ecosystems. Present global VOC models predict that base emissions of isoprene from tropical rainforests are considerably higher than from savannas. These global models of VOC emissions which rely mainly on species inventories are useful, but significant improvement might be made with more ecologically based models of VOC emissions by plants. Ecosystems along a successional transect from woodland savanna to primary rainforest in central Africa were characterized for species composition and vegetation abundance using ground surveys and remotely sensed data. A total of 336 species (mostly trees) at 13 sites were recorded, and 208 of these were measured for VOC emissions at near-optimal light and temperature conditions using a leaf cuvette and hand-held photoionization detector (PID). A subset of 59 species was also sampled using conventional VOC emission techniques in order to validate the PID technique. Results of ecological and VOC emission surveys indicate both phylogenetic and successional patterns along the savanna-rainforest transect. Genera and families of trees which tend to emit isoprene include Lophira, Irvingia, Albizia, Artocarpus, Ficus, Pterocarpus, Caesalpiniaceae, Arecaceae, and Moraceae. Other taxa tend to contain stored VOCs (Annonaceae and Asteraceae). Successional patterns suggest that isoprene emissions are highest in the relatively early successional Isoberlinia forest communities and progressively decrease in the later successional secondary and primary rainforest communities. Stored VOCs appear to increase along the savanna-rainforest succession, but these data are more tentative. These findings are consistent with

  7. Impact of resistant starch on body fat patterning and central appetite regulation.

    Directory of Open Access Journals (Sweden)

    Po-Wah So

    Full Text Available BACKGROUND: Adipose tissue patterning has a major influence on the risk of developing chronic disease. Environmental influences on both body fat patterning and appetite regulation are not fully understood. This study was performed to investigate the impact of resistant starch (RS on adipose tissue deposition and central regulation of appetite in mice. METHODOLOGY AND PRINCIPLE FINDINGS: Forty mice were randomised to a diet supplemented with either the high resistant starch (HRS, or the readily digestible starch (LRS. Using (1H magnetic resonance (MR methods, whole body adiposity, intrahepatocellular lipids (IHCL and intramyocellular lipids (IMCL were measured. Manganese-enhanced MRI (MEMRI was used to investigate neuronal activity in hypothalamic regions involved in appetite control when fed ad libitum. At the end of the interventional period, adipocytes were isolated from epididymal adipose tissue and fasting plasma collected for hormonal and adipokine measurement. Mice on the HRS and LRS diet had similar body weights although total body adiposity, subcutaneous and visceral fat, IHCL, plasma leptin, plasma adiponectin plasma insulin/glucose ratios was significantly greater in the latter group. Adipocytes isolated from the LRS group were significantly larger and had lower insulin-stimulated glucose uptake. MEMRI data obtained from the ventromedial and paraventricular hypothalamic nuclei suggests a satiating effect of the HRS diet despite a lower energy intake. CONCLUSION AND SIGNIFICANCE: Dietary RS significantly impacts on adipose tissue patterning, adipocyte morphology and metabolism, glucose and insulin metabolism, as well as affecting appetite regulation, supported by changes in neuronal activity in hypothalamic appetite regulation centres which are suggestive of satiation.

  8. Auto-Pattern Programmable Kernel Filter (Auto-PPKF for Suppression of Bot Generated Traffic

    Directory of Open Access Journals (Sweden)

    Kritika Govind

    2013-11-01

    Full Text Available Bots usually vary from their other malicious counter parts by periodically reporting to the botmaster through regular exchange of messages. Our experiments on bot attack generation showed a continuous exchange of packets with similar content between the botmaster and the zombie machine at various time intervals. Though there were also genuine packets with similar content being sent out of the victim machine challenge was to differentiate between the two and pass only the genuine ones. In this paper, an algorithm namely Auto-Pattern Programmable Kernel Filter (Auto-PPKF, for automatic detection of patterns from packet payload for filtering out malicious packets generated by bots is proposed. The significant feature of our proposed Auto-PPKF algorithm is that, the malicious pattern is deduced at kernel level on the fly from packet payload. Traditional algorithms such as Boyer Moore, Knuth Morris Patt, and Naive Pattern search algorithms require the pattern to be identified available a priori. Currently, Longest Common Subsequence (LCS algorithm stands as the most preferred algorithm for pattern matching. But the disadvantage is that common sequences can also exist in many genuine packets. Hence, the challenge lies in automatic detection of malicious patterns and filtering of the packets having such malicious patterns. This would not only put off the communication between the Botmaster and Zombie machine, but will also thus prevent user information from being sent to the botmaster.

  9. Assessing incentive policies for integrating centralized solar power generation in the Brazilian electric power system

    International Nuclear Information System (INIS)

    This study assesses the impacts of promoting, through auctions, centralized solar power generation (concentrated solar power – CSP, and photovoltaic solar panels – PV) on the Brazilian power system. Four types of CSP plants with parabolic troughs were simulated at two sites, Bom Jesus da Lapa and Campo Grande, and PV plants were simulated at two other sites, Recife and Rio de Janeiro. The main parameters obtained for each plant were expanded to other suitable sites in the country (totaling 17.2 GW in 2040), as inputs in an optimization model for evaluating the impacts of the introduction of centralized solar power on the expansion of the electricity grid up to 2040. This scenario would be about USD$ 185 billion more expensive than a business as usual scenario, where expansion solely relies on least-cost options. Hence, for the country to incentivize the expansion of centralized solar power, specific auctions for solar energy should be adopted, as well as complementary policies to promote investments in R and D and the use of hybrid systems based on solar and fuels in CSP plants. - Highlights: • We assess the impacts of promoting centralized CSP and PV by auctions in Brazil. • We simulate energy scenarios with and without solar power. • Our solar scenario leads to 17 GW of solar capacity installed between 2020 and 2040. • This solar scenario is some USD$ 185 billion more expensive than the base case

  10. High-fidelity spherical cholesteric liquid crystal Bragg reflectors generating unclonable patterns for secure authentication

    Science.gov (United States)

    Geng, Yong; Noh, Junghyun; Drevensek-Olenik, Irena; Rupp, Romano; Lenzini, Gabriele; Lagerwall, Jan P. F.

    2016-05-01

    Monodisperse cholesteric liquid crystal microspheres exhibit spherically symmetric Bragg reflection, generating, via photonic cross communication, dynamically tuneable multi-coloured patterns. These patterns, uniquely defined by the particular sphere arrangement, could render cholesteric microspheres very useful in countless security applications, as tags to identify and authenticate their carriers, mainly physical objects or persons. However, the optical quality of the cholesteric droplets studied so far is unsatisfactory, especially after polymerisation, a step required for obtaining durable samples that can be used for object identification. We show that a transition from droplets to shells solves all key problems, giving rise to sharp patterns and excellent optical quality even after polymerisation, the polymerised shells sustaining considerable mechanical deformation. Moreover, we demonstrate that, counter to prior expectation, cross communication takes place even between non-identical shells. This opens additional communication channels that add significantly to the complexity and unique character of the generated patterns.

  11. A Walking Pattern Generation Method for Humanoid Robots Using Least Square Method and Quartic Polynomial

    OpenAIRE

    Hong, Seokmin; Oh, Yonghwan; Chang, Young-Hwan; You, Bum-Jae

    2009-01-01

    This paper proposed a new walking pattern method for the humanoid robot. The propose method was based on the linear inverted pendulum model as the simple model of humanoid robot. And this method consisted of three step modules for generating walking pattern. Using these step modules, this paper addressed robustness of the proposed method against initial values of the ZMP and CoM, and validated the efficiency with the slope at the single support phase through simulations. And finally we showed...

  12. Towards a Pattern-based Automatic Generation of Logical Specifications for Software Models

    OpenAIRE

    Klimek, Radoslaw

    2014-01-01

    The work relates to the automatic generation of logical specifications, considered as sets of temporal logic formulas, extracted directly from developed software models. The extraction process is based on the assumption that the whole developed model is structured using only predefined workflow patterns. A method of automatic transformation of workflow patterns to logical specifications is proposed. Applying the presented concepts enables bridging the gap between the benefits of deductive rea...

  13. The activation pattern of macrophages in giant cell (temporal) arteritis and primary angiitis of the central nervous system.

    Science.gov (United States)

    Mihm, Bernhard; Bergmann, Markus; Brück, Wolfgang; Probst-Cousin, Stefan

    2014-06-01

    To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14-positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8-positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8-positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process.

  14. When does colonisation of a semi-arid hillslope generate vegetation patterns?

    Science.gov (United States)

    Sherratt, Jonathan A

    2016-07-01

    Patterned vegetation occurs in many semi-arid regions of the world. Most previous studies have assumed that patterns form from a starting point of uniform vegetation, for example as a response to a decrease in mean annual rainfall. However an alternative possibility is that patterns are generated when bare ground is colonised. This paper investigates the conditions under which colonisation leads to patterning on sloping ground. The slope gradient plays an important role because of the downhill flow of rainwater. One long-established consequence of this is that patterns are organised into stripes running parallel to the contours; such patterns are known as banded vegetation or tiger bush. This paper shows that the slope also has an important effect on colonisation, since the uphill and downhill edges of an isolated vegetation patch have different dynamics. For the much-used Klausmeier model for semi-arid vegetation, the author shows that without a term representing water diffusion, colonisation always generates uniform vegetation rather than a pattern. However the combination of a sufficiently large water diffusion term and a sufficiently low slope gradient does lead to colonisation-induced patterning. The author goes on to consider colonisation in the Rietkerk model, which is also in widespread use: the same conclusions apply for this model provided that a small threshold is imposed on vegetation biomass, below which plant growth is set to zero. Since the two models are quite different mathematically, this suggests that the predictions are a consequence of the basic underlying assumption of water redistribution as the pattern generation mechanism. PMID:26547308

  15. Post-release survival and movements patterns of roosterfish (Nematistius pectoralis off the Central American coastline

    Directory of Open Access Journals (Sweden)

    Chugey A Sepulveda

    2015-03-01

    Full Text Available Acoustic telemetry was used to assess immediate post-release survival and track the short-term movement patterns of roosterfish Nematistius pectoralis between 2008 and 2010. Seven roosterfish (85 to 146 cm fork length, FL were continuously tracked along the Central American coastline for periods of up to 28 h following capture on recreational fishing tackle. All seven roosterfish were initially captured and spent the duration of the track period proximal to the coastline in waters <100 m of depth. From depth records and horizontal movements, it was determined that all seven roosterfish survived the acute effects of capture. The greatest depth achieved by any of the tracked individuals was 62 m and collectively roosterfish spent over 90% of the track records between the surface and 12 m. For all tracks, fish size showed no effect on maximum or average dive depth and the average day (7 ± 2 m and night (6 ± 2 m depths were similar among individuals. Mean water temperature for all tracks was 28 ± 1°C, with the lowest temperature experienced at depth being 23°C. Total horizontal movements from the roosterfish in this study ranged from 14.7 to 42.2 km and averaged 1.5 ± 0.4 km h-1. Data on movements in relation to bathymetry, prey presence and habitat structure are discussed. Collectively, these data provide insight into the immediate post-release disposition and short-term movements of this poorly studied species along the coast of Central America.

  16. Climatic patterns and extreme rainfalls on coastal areas in Central Italy

    Science.gov (United States)

    Bramati, M. C.; Tarragoni, C.

    2012-04-01

    In this paper we focus on the extreme values analysis to estimate the rainfall return levels for some Adriatic and Tyrrhenian coastal areas in central Italy. Two approaches are mainly considered: the first one is based on the maximum annual daily rainfall series (1-day, 2-day and 3-day) for which suitable probability distributions are fitted, whereas the second one is based on the series of peaks over annual thresholds (POT) for which the best fitting Generalized Pareto distribution is identified. Spectral analysis and appropriate tests for stationarity and homogeneity are run in order to verify the hypothesis under which the analysis performed is valid. From the density plots and the parameter estimates of the fitted distributions to the various annual maximum rainfall series we can conclude that there is a different pattern in the occurrence of extreme events for the western coast with respect to the eastern coast. Specifically, on the Tyrrhenian side extreme rainfalls are more likely to happen in correspondence of longer time spans (i.e. 3-day series) as the effect of cumulated stable rainfalls over time. On the opposite, for the Adriatic coast extremes are more frequent in shorter time spans (1-day). A vector autoregressive model is then estimated and through a causal ordering the identifying restrictions are set. The impulse response analysis shows a lag in the transmission of rainfall shocks of the central Adriatic coast to the Tyrrhenian one. This paper is prepared as a background paper to the SECOA N1.2 Report: Assessment of frequency-magnitude of extreme rainfall events and flooding. Project SECOA (Solutions for Environmental contrast in Coastal Areas) is funded by the EU Commission within the 7th Framework Programme (2007-2013).

  17. Mediterranean climate patterns and wine quality in North and Central Italy.

    Science.gov (United States)

    Dalu, John David; Baldi, Marina; Marta, Anna Dalla; Orlandini, Simone; Maracchi, Gianpiero; Dalu, Giovanni; Grifoni, Daniele; Mancini, Marco

    2013-09-01

    Results show that the year-to-year quality variation of wines produced in North and Central Italy depends on the large-scale climate variability, and that the wine quality improvement in the last four decades is partially due to an increase of temperature and to a decrease of precipitation in West and Central Mediterranean Europe (WME; CME). In addition, wine quality is positively correlated with air temperature throughout the entire active period of the grapevine, weakly negatively correlated with precipitation in spring, and well negatively correlated in summer and fall. The month-to-month composites of the NAO anomaly show that, in years of good quality wine, this anomaly is negative in late spring, oscillates around zero in summer, and is positive in early fall; while, in years of bad quality wine, it is positive in late spring and summer, and negative in early fall, i.e. its polarity has an opposite sign in spring and fall in good versus bad years. The composite seasonal maps show that good wines are produced when the spring jet stream over the Atlantic diverts most of the weather perturbations towards North Europe, still providing a sufficient amount of rainwater to CME; when summer warming induced by southerly winds is balanced by the cooling induced by westerly winds; and when a positive geopotential anomaly over WME shelters CME from fall Atlantic storms. Bad quality wines are produced when the jet stream favors the intrusion of the Atlantic weather perturbations into the Mediterranean. Results suggest that atmospheric pattern persistencies can be used as precursors for wine quality forecast. PMID:23152193

  18. Novel Unique Technique for Generating Ticket Identifier Using Image Texture Patterns

    Directory of Open Access Journals (Sweden)

    Mrs. Jayashree Katti

    2014-05-01

    Full Text Available A paperless ticketing system with an application through which user can purchase a mobile ticket. Once the purchasing information is provided, the mobile ticket can be sent to the respective users mobile. A new method is introduced to generate tickets in which texture pattern is generated for digest provided by md5. The ticket is sent in the format of image consisting of texture patterns. Ticket can be verified by ticket checker using an application developed to verify genuine ticket. This system will be a revolution in the m-commerce world.

  19. Staff Draft Report. Comparative Cost of California Central Station Electricity Generation Technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Badr, Magdy; Benjamin, Richard

    2003-02-11

    This Energy Commission staff draft report presents preliminary levelized cost estimates for several generic central-station electricity generation technologies. California has traditionally adopted energy policies that balance the goals of supporting economic development, improving environmental quality and promoting resource diversity. In order to be effective, such policies must be based on comprehensive and timely gathering of information. With this goal in mind, the purpose of the report is to provide comparative levelized cost estimates for a set of renewable (e.g., solar) and nonrenewable (e.g., natural gas-fired) central-station electricity generation resources, based on each technology's operation and capital cost. Decision-makers and others can use this information to compare the generic cost to build specific technology. These costs are not site specific. If a developer builds a specific power plant at a specific location, the cost of siting that plant at that specific location must be considered. The Energy Commission staff also identifies the type of fuel used by each technology and a description of the manner in which the technology operates in the generation system. The target audiences of this report are both policy-makers and anyone wishing to understand some of the fundamental attributes that are generally considered when evaluating the cost of building and operating different electricity generation technology resources. These costs do not reflect the total cost to consumers of adding these technologies to a resources portfolio. These technology characterizations do not capture all of the system, environmental or other relevant attributes that would typically be needed by a portfolio manager to conduct a comprehensive ''comparative value analysis''. A portfolio analysis will vary depending on the particular criteria and measurement goals of each study. For example, some form of firm capacity is typically needed with wind

  20. Simultaneous detection of both GDNF and GFRα1 expression patterns in the mouse central nervous system

    Directory of Open Access Journals (Sweden)

    Clara Ortega-de San Luis

    2016-06-01

    Full Text Available Glial cell line-derived neurotrophic factor (GDNF is proposed as a therapeutic tool in Parkinson’s disease, addiction-related disorders, and neurodegenerative conditions affecting motor neurons. Despite the high amount of work about GDNF therapeutic application, the neuronal circuits requiring GDNF trophic support in the brain and spinal cord are poorly characterized. Here, we defined GDNF and GDNF family receptor-α 1 (GFRα1 expression pattern in the brain and spinal cord of newborn and adult mice. We performed systematic and simultaneous detection of EGFP and LacZ expressing alleles in reporter mice and asked whether modifications of this signaling pathway lead to a significant central nervous system (CNS alteration. GFRα1 was predominantly expressed by neurons but also by an unexpected population of non-neuronal cells. GFRα1 expression pattern was wider in neonatal than in adult CNS and GDNF expression was restricted in comparison with GFRα1 at both developmental time points. The use of confocal microscopy to imaging X-gal deposits and EGFP allowed us to identify regions containing cells that expressed both proteins and to discriminate between auto and non-autotrophic signaling. We also suggested long-range GDNF-GFRα1 circuits taking advantage of the ability of the EGFP genetically encoded reporter to label long distance projecting axons. The complete elimination of either the ligand or the receptor during development did not produce major abnormalities, suggesting a preponderant role for GDNF signaling during adulthood. In the spinal cord, our results pointed to local modulatory interneurons as the main target of GDNF produced by Clarke’s column cells. Our work increases the understanding on how GDNF signals in the CNS and establish a crucial framework for posterior studies addressing either the biological role of GDNF or the optimization of trophic factor-based therapies.

  1. Semi-arid Vegetation Pattern, Stability and Suitability to Suppress Sand Movement in Central Sudan

    Directory of Open Access Journals (Sweden)

    N.K.N. Al-Amin

    2011-01-01

    Full Text Available Moving sand that threatens Gezira scheme is the dominant land degradation feature in central Sudan and the front line defence is the sparse scattered natural vegetation of the area. The study aimed to assess the role of this vegetation to suppress drifting sand and to monitor their ability to face the impact of climate change and human activity (deforestation. The dimensions of the sand captured by single tree of dominant species, Acacia tortilis, Leptadenia pyrotechnica, Prosopis juliflora and Panicum turgidum were measured and the volumes were calculated. To picture the drought pattern 5-year running means of annual rainfalls (1941-2007 of the study area were calculated and compared with long-term mean. Deforestation was indicated by local community wood consumption in relation to the average woody biomass (in good condition. The results show that scattered trees of the right densities had potentiality to settle drifting sand, but they were subjected to 20 years dry seasons followed by only 4 wet years and now are subjected to a new era of dry spell. This condition is not in favour of the semi-arid vegetation pattern sustainability and a suitable measure to enhance natural regeneration is needed. In addition, the community's wood demand was higher than the resource, where a person would destroy 0.5 ha/year compared to 0.9 ha/year per person available reveals the magnitude of deforestation. Encouragement of farmers to use alternative energy sources and functional application of laws and regulations to protect the existing vegetation rem ain crucial.

  2. Patterns of mercury dispersion from local and regional emission sources, rural Central Wisconsin, USA

    Directory of Open Access Journals (Sweden)

    A. Kolker

    2010-01-01

    Full Text Available Simultaneous real-time changes in mercury (Hg speciation – reactive gaseous Hg (RGM, elemental Hg (Hg°, and fine particulate Hg (Hg-PM2.5, were determined from June to November 2007, in ambient air at three locations in rural Central Wisconsin. Known Hg emission sources within the airshed of the monitoring sites include: 1 a 1114 megawatt (MW coal-fired electric utility generating station; 2 a Hg-bed chlor-alkali plant; and 3 a smaller (465 MW coal-burning electric utility. Monitoring sites, showing sporadic elevation of RGM, Hg° and Hg-PM2.5, were positioned at distances of 25, 50 and 100 km northward of the larger electric utility. A series of RGM events were recorded at each site. The largest, on 23 September, occurred under prevailing southerly winds, with a maximum RGM value (56.8 pg m−3 measured at the 100 km site, and corresponding elevated SO2 (10.41 ppbv; measured at 50 km site. The finding that RGM, Hg°, and Hg-PM2.5 are not always highest at the 25 km site, closest to the large generating station, contradicts the idea that RGM decreases with distance from a large point source. This may be explained if: 1 the 100 km site was influenced by emissions from the chlor-alkali facility or by RGM from regional urban sources; 2 the emission stack height of the larger power plant promoted plume transport at an elevation where the Hg is carried over the closest site; or 3 RGM was being generated in the plume through oxidation of Hg°. Operational changes at each emitter since 2007 should reduce their Hg output, potentially allowing quantification of the environmental benefit in future studies.

  3. Implementation of a Data Packet Generator Using Pattern Matching for Wearable ECG Monitoring Systems

    OpenAIRE

    Yun Hong Noh; Do Un Jeong

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphi...

  4. Distribution pattern and conservation of threatened medicinal and aromatic plants of Central Himalaya, India

    Institute of Scientific and Technical Information of China (English)

    L. S. Kandari; K.S. Rao; R. K. Maikhuri; G. Kharkwal; K. Chauhan; C.P. Kala

    2011-01-01

    A study was conducted to examine the distribution pattern of four rhizomatous medicinal and aromatic plant species (MAPs) viz., Angelica glauca, Pleurospermum angelicoides, Rheum emodi and Arne- bia benthamii in different forest stands in Central Himalaya. Results show that A. Glauca and P. Angelicoides had a higher (50%) frequency at Chipkoan, Garpak and Phagati forest, R. Emodi had a higher (60%) fre- quency at Rishikund, Suki and Himtoli, and A. Benthamii had a higher (70%) frequency at Suki and Khambdhar The densities of A. Glauca (0.6 plants·m) and P. Angelicoides (0.5 plants·m) were higher at Chipkoan and Garpak sites than at other micro-sites, while densities of R. Emodi (0.8 plants·m) and A. Benthamii (1.0 plants·m) were higher at Suki and Khambdhar sites. A. Glauca had highest total basal covers (TBC) (1.2 cm·m) at Chipkoan, P. Angelicoides had highest TBC (0.92 cm·m) at Lati kharak site, A. Benthamii had the highest TBC (6.48 cm·m) at Khambdhar, and R. Emodi had highest TBC (4.53 cm·m) at Rishikund. For the four studied species, A. Glauca showed a contagious distribution, P. Angelicoides and R. Emodi showed the random and A. Benthamii showed the regular type of distribution.

  5. Deleterious Emission Abatement through Structured Energy Use Pattern: A North Central Nigeria Perspective

    Directory of Open Access Journals (Sweden)

    Ajayi-Banji Ademola

    2016-05-01

    Full Text Available Holistic view of household energy consumption based on greenhouse gas emissions in the North Central cities of Nigeria was examined in this study. Scenarios considered were based on income level of energy users (low and high and energy metering system (i.e. pre-paid and post-paid energy billing systems. Strong direct nexus was observed between energy use and emissions pattern. Energy utilization by post-paid category had higher weekly average value of 35.09 and 41.70 kWh as against 23.18 and 33.38 kWh for low and high income pre-paid consumers respectively. Energy use and greenhouse gas emissions from both classification followed similar trend. Data obtained and analysed in the study show that global warming and acidification potentials could be reduced by 33.94 and 19.95 % for low and high income category consumers when pre-paid meters are in place. Conclusively, energy system users with pre-paid metering system displayed reasonable level of management decisions that reduce energy wastage and consequently environmental negative impacts.

  6. Morphotectonic analysis, structural evolution/pattern of a contractional ridge: Giouchtas Mt., Central Crete, Greece

    Indian Academy of Sciences (India)

    Kokinou Eleni; Skilodimou Hariklia D; Bathrellos George D; Antonarakou Assimina; Kamberis Evangelos

    2015-04-01

    The Giouchtas Mountain is situated south of Heraklion, Central Crete. It is a N–S trending morphological asymmetric ridge with a steep western slope, whilst its eastern slope is characterized by a smoother relief, composed of Mesozoic limestone and Eocene–lower Oligocene flysch of the Gavrovo–Tripolis zone. The present study focusses on the structural pattern and development of Giouchtas Mountain. Morphotectonic analyses in combination with field mapping and tectonic analysis were performed for this purpose. GIS techniques were used for mapping the spatial distribution of the geological features on the topographic relief of the area. Geomorphic indices, used in the present study, are the mountain front sinuosity index (Smf) and the valley floor/width ratio index (Vf). Based on Smf and Vf values, it is implied that this area can be assigned to a tectonic class I, corresponding to higher tectonic activity. However, spatial variations of the tectonic activity along the segmented fronts point to a general trend of increasing activity towards the north and especially, northeast. The model of this possibly active structural feature corresponds to a compressional mechanism followed by an earliest Mid. Miocene to Holocene late-stage deformation related to extensional faulting.

  7. Deleterious Emission Abatement through Structured Energy Use Pattern: A North Central Nigeria Perspective

    Science.gov (United States)

    Ajayi-Banji, Ademola; Omotosho, Olayinka; Amori, Anthony; Alao, Damilola; Igbode, Imoisime; Abimbola, Olufemi

    2016-05-01

    Holistic view of household energy consumption based on greenhouse gas emissions in the North Central cities of Nigeria was examined in this study. Scenarios considered were based on income level of energy users (low and high) and energy metering system (i.e. pre-paid and post-paid energy billing systems). Strong direct nexus was observed between energy use and emissions pattern. Energy utilization by post-paid category had higher weekly average value of 35.09 and 41.70 kWh as against 23.18 and 33.38 kWh for low and high income pre-paid consumers respectively. Energy use and greenhouse gas emissions from both classification followed similar trend. Data obtained and analysed in the study show that global warming and acidification potentials could be reduced by 33.94 and 19.95 % for low and high income category consumers when pre-paid meters are in place. Conclusively, energy system users with pre-paid metering system displayed reasonable level of management decisions that reduce energy wastage and consequently environmental negative impacts.

  8. Land use patterns and the risk of West Nile virus transmission in central Illinois.

    Science.gov (United States)

    Gardner, Allison M; Lampman, Richard L; Muturi, Ephantus J

    2014-05-01

    Understanding how human land use patterns influence mosquito ecology and the risk of mosquito-borne pathogens is critical for the development of disease management strategies. We examined how different environments influenced mosquito species composition, abundance, and West Nile virus (WNV) infection rates in central Illinois. Using a combination of gravid traps and CDC light traps, adult mosquitoes were collected every other week from June 24 to September 16, 2012, in four major land use categories-row crops, prairies, forest fragments, and residential neighborhoods. The mosquitoes were identified to species morphologically, and pools of pure and mixed Culex mosquitoes (primarily Culex pipiens and Culex restuans) were tested for WNV-RNA by qRT-PCR. Mosquito species diversity was significantly higher in forest habitats compared to residential, agricultural, and prairie land use categories. All the four landscape types were equally important habitats for WNV vectors Cx. pipiens and Cx. restuans, contrary to previous findings that these species principally inhabit the residential areas. WNV-infected mosquito pools were observed in all land use types, and the infection rates overlapped among land use categories. Although our findings support the importance of residential habitats for WNV transmission to humans, they also establish that prairie, row crops, and wood lots are potentially important refuges for enzootic transmission. This is particularly important in urban ecosystems where these land use categories are small, interspersed fragments serving as potential refuge sites during periods of low rainfall. PMID:24746038

  9. Socio-Economic Factors Affecting Home Internet Usage Patterns in Central Queensland

    Directory of Open Access Journals (Sweden)

    Wal J. Taylor

    2003-01-01

    Full Text Available Governments and other policy makers are concerned with the gap in home Internet usage between people from metropolitan and rural areas. A survey conducted in Central Queensland, Australia examined differences in home Internet usage patterns between young and old, male and female, people in urban and rural areas, married and unmarried, well-educated and less educated, rich and poor, and employed and unemployed and found significant differences. These results highlight areas for further research and provide a basis for government agencies and industries to consider these associations in future policy formulation for regional development using ICT. The research suggested that further research should be conducted to monitor consuming behaviors of the youngest age group in Internet use for entertainment and information search in order to detect possible Internet overuse or addiction. In addition, further research should be conducted to find out what people search for on the Internet, and if for employment opportunities, financial incentives are suggested for the unemployed people.

  10. Student-Generated Content in College Teaching: Content Quality, Behavioural Pattern and Learning Performance

    Science.gov (United States)

    Yang, X.; Guo, X.; Yu, S.

    2016-01-01

    This study investigates the quality of course content, behavioural patterns of students and learning performance in teaching of student-generated content (SGC). A total of 49 third-year university students in educational technology participated in this study. By combining the methods of questionnaire, lag sequence analysis and interview, the study…

  11. Pattern-generating travelling waves in a discrete multicellular system with lateral inhibition

    Science.gov (United States)

    Plahte, Erik; Øyehaug, Leiv

    2007-02-01

    On a one-dimensional string of cells, the juxtacrine signalling model for Delta-Notch lateral inhibition by Collier et al. [J.R. Collier, N.A.M. Monk, P.K. Maini, J.H. Lewis, Pattern formation by lateral inhibition with feedback: A mathematical model of Delta-Notch intercellular interaction, J. Theoret. Biol. 183 (1996) 429-446] exhibits a predominant alternating pattern of cells expressing either Delta or Notch, as well as many aperiodic patterns. Despite this multistationarity, in the idealised situation of no noise, travelling waves invading the unstable, homogeneous state only generate the predominant alternating pattern in their wake all over the lattice. However, this robustness is totally lost in the presence of stochastic noise because the invaded, initial state is unstable. Using linear approximations around the initial, homogeneous state and around the final, patterned state, we are able to derive analytically all essential properties of the wave: the shape of the wave front, the unique, alternating pattern generated by the wave, and the asymptotic speed of the wave front. We show that the asymptotic wave speed equals the theoretical minimum wave speed. The latter agrees extremely well with the value estimated from numerical simulations. Thus, in this system travelling waves are pulled by the leading edge of the front.

  12. Simulation of an offshore wind farm using fluid power for centralized electricity generation

    Science.gov (United States)

    Jarquin-Laguna, A.

    2016-09-01

    A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents two examples of the time-domain simulation results for an hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm with conventional technology turbines, using the same wind farm layout and environmental conditions. For the presented case study, results indicate that the individual wind turbines are able to operate within operational limits with the current pressure control concept. Despite the stochastic turbulent wind input and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions.

  13. Overhaul of the generator of the hydroelectric central station Ingeniero Carlos Ramirez Ulloa; Rehabilitacion del generador de la unidad 2 de la central hidroelectrica ingeniero Carlos Ramirez Ulloa

    Energy Technology Data Exchange (ETDEWEB)

    Robles Pimentel, Edgar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Garcia Hernandez, Javier [Comision Federal de Electricidad, Mexico, D. F. (Mexico)

    1997-12-31

    In November 1995, the failure of the Unit 2 generator at the hydroelectric central station Ingeniero Carlos Ramirez Ulloa, El Caracol, occurred. The accident forced to carry out its overhaul. Here are presented the technical problems faced during the overhaul of the generator and analyzed the implemented solutions. [Espanol] En noviembre de 1995 ocurrio la falla del generador de la unidad 2 de la central hidroelectrica Ing. Carlos Ramirez Ulloa, El Caracol. El accidente obligo a llevar a cabo su rehabilitacion. Se presentan los problemas tecnicos enfrentados durante la rehabilitacion del generador y se discuten las soluciones implementadas.

  14. Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites.

    Science.gov (United States)

    González Pericot, N; Villoria Sáez, P; Del Río Merino, M; Liébana Carrasco, O

    2014-11-01

    The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites. PMID:25081852

  15. Intake-to-delivered-energy ratios for central station and distributed electricity generation in California

    International Nuclear Information System (INIS)

    In previous work, we showed that the intake fraction (iF) for nonreactive primary air pollutants was 20 times higher in central tendency for small-scale, urban-sited distributed electricity generation (DG) sources than for large-scale, central station (CS) power plants in California [Heath, G.A., Granvold, P.W., Hoats, A.S., Nazaroff, W.W., 2006. Intake fraction assessment of the air pollutant exposure implications of a shift toward distributed electricity generation. Atmospheric Environment 40, 7164-7177]. The present paper builds on that study, exploring pollutant- and technology-specific aspects of population inhalation exposure from electricity generation. We compare California's existing CS-based system to one that is more reliant on DG units sited in urban areas. We use Gaussian plume modeling and a GIS-based exposure analysis to assess 25 existing CSs and 11 DG sources hypothetically located in the downtowns of California's most populous cities. We consider population intake of three pollutants - PM2.5, NOx and formaldehyde - directly emitted by five DG technologies - natural gas (NG)-fired turbines, NG internal combustion engines (ICE), NG microturbines, diesel ICEs, and fuel cells with on-site NG reformers. We also consider intake of these pollutants from existing CS facilities, most of which use large NG turbines, as well as from hypothetical facilities located at these same sites but meeting California's best-available control technology standards. After systematically exploring the sensitivity of iF to pollutant decay rate, the iFs for each of the three pollutants for all DG and CS cases are estimated. To efficiently compare the pollutant- and technology-specific exposure potential on an appropriate common basis, a new metric is introduced and evaluated: the intake-to-delivered-energy ratio (IDER). The IDER expresses the mass of pollutant inhaled by an exposed population owing to emissions from an electricity generation unit per quantity of electric

  16. Patterns of mercury dispersion from local and regional emission sources, rural Central Wisconsin, USA

    Directory of Open Access Journals (Sweden)

    A. Kolker

    2010-05-01

    Full Text Available Simultaneous real-time changes in mercury (Hg speciation- reactive gaseous Hg (RGM, elemental Hg (Hg°, and fine particulate Hg (Hg-PM2.5, were determined from June to November, 2007, in ambient air at three locations in rural Central Wisconsin. Known Hg emission sources within the airshed of the monitoring sites include: 1 a 1114 megawatt (MW coal-fired electric utility generating station; 2 a Hg-bed chlor-alkali plant; and 3 a smaller (465 MW coal-burning electric utility. Monitoring sites, showing sporadic elevation of Hg°, Hg-PM2.5, and RGM were positioned at distances of 25, 50 and 100 km northward of the larger electric utility. Median concentrations of Hg°, Hg-PM2.5, and RGM were 1.3–1.4 ng m−3, 2.6–5.0 pg m−3, and 0.6–0.8 pg m−3, respectively. A series of RGM events were recorded at each site. The largest, on 23 September, occurred under prevailing southerly winds, with a maximum RGM value (56.8 pg m-3 measured at the 100 km site, and corresponding elevated SO2 (10.4 ppbv; measured at 50 km site. The finding that RGM, Hg°, and Hg-PM2.5 are not always highest at the 25 km site, closest to the large generating station, contradicts the idea that RGM decreases with distance from a large point source. This may be explained if: 1 the 100 km site was influenced by emissions from the chlor-alkali facility or by RGM from regional urban sources; 2 the emission stack height of the larger power plant promoted plume transport at an elevation where the Hg is carried over the closest site; or 3 RGM was being generated in the plume through oxidation of Hg°. Operational changes at each emitter since 2007 should reduce their Hg output, potentially allowing quantification of the environmental benefit in future studies.

  17. Czech alien flora and the historical pattern of its formation: what came first to Central Europe?

    Science.gov (United States)

    Pysek, Petr; Sádlo, Jirí; Mandák, Bohumil; Jarosík, Vojtech

    2003-03-01

    Temporal patterns of immigration to the country were analysed using 668 alien species in the flora of the Czech Republic for which the dates of the first record were available (64.8% of the total number of 1031 so-called neophytes, i.e. aliens introduced after the year 1500). After a period of initial slow increase lasting to the 1840s, the accumulation of neophytes over time could be best fitted by a linear model that explained 97% of the variance. The intensity of floristic research, which varied between periods, did not significantly affect the overall increase in the number of aliens. The effect of species traits on the year of introduction was evaluated, with continent of origin, introduction type (deliberate or accidental), life history, Grime's life strategy, onset of flowering, mode of dispersal and propagule size as explanatory variables. Species of European origin and CSR strategists arrived earlier than those with other origins and strategies. Deliberately introduced species appeared earlier than accidental arrivals, and those cultivated for utilitary reasons on average arrived earlier than ornamentals. Species capable of early flowering were remarkably more prevalent among early newcomers. A separate analysis of accidentally introduced American species also identified life history as a significant predictor of immigration time, with annuals being introduced earlier than biennials and perennials. The data contribute to an understanding of a crucial stage of the invasion process that has received little attention in the literature. The model "early alien" to Central Europe is a European species with a CSR strategy deliberately brought for cultivation as a utilitary plant. Once it escaped from cultivation, its establishment in the wild was favoured by its ability to flower early and, therefore, complete the life cycle. PMID:12647111

  18. Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

    Energy Technology Data Exchange (ETDEWEB)

    González Pericot, N., E-mail: natalia.gpericot@upm.es [Escuela Técnica Superior de Edificación, Universidad Politécnica de Madrid, Calle Juan de Herrera n°6, 28040 Madrid (Spain); Villoria Sáez, P., E-mail: paola.villoria@upm.es [Escuela Técnica Superior de Edificación, Universidad Politécnica de Madrid, Calle Juan de Herrera n°6, 28040 Madrid (Spain); Del Río Merino, M., E-mail: mercedes.delrio@upm.es [Escuela Técnica Superior de Edificación, Universidad Politécnica de Madrid, Calle Juan de Herrera n°6, 28040 Madrid (Spain); Liébana Carrasco, O., E-mail: oscar.liebana@uem.es [Escuela de Arquitectura, Universidad Europea de Madrid, Calle Tajo s/n, 28670 Villaviciosa de Odón (Spain)

    2014-11-15

    Highlights: • On-site segregation level: 1.80%; training and motivation strategies were not effective. • 70% Cardboard waste: from switches and sockets during the building services stage. • 40% Plastic waste: generated during structures and partition works due to palletizing. • >50% Wood packaging waste, basically pallets, generated during the envelope works. - Abstract: The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.

  19. Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

    International Nuclear Information System (INIS)

    Highlights: • On-site segregation level: 1.80%; training and motivation strategies were not effective. • 70% Cardboard waste: from switches and sockets during the building services stage. • 40% Plastic waste: generated during structures and partition works due to palletizing. • >50% Wood packaging waste, basically pallets, generated during the envelope works. - Abstract: The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites

  20. Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis

    Science.gov (United States)

    Menasria, Rafik; Canivet, Coraline; Piret, Jocelyne; Boivin, Guy

    2015-01-01

    The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1) encephalitis (HSE). To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2x106 plaque forming units). Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P<0.05) and «Ly6Chi» inflammatory monocytes (P<0.001) significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P<0.05 for inflammatory monocytes compared to non-infected controls) to reach baseline levels on day 10 following infection. The percentage of «Ly6Clow» patrolling monocytes significantly increased (P<0.01) at a later time point (day 8), which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus, our findings suggest

  1. Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis.

    Directory of Open Access Journals (Sweden)

    Rafik Menasria

    Full Text Available The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1 encephalitis (HSE. To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2 x 10(6 plaque forming units. Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P < 0.05 and "Ly6C hi" inflammatory monocytes (P < 0.001 significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P < 0.05 for inflammatory monocytes compared to non-infected controls to reach baseline levels on day 10 following infection. The percentage of "Ly6C low" patrolling monocytes significantly increased (P < 0.01 at a later time point (day 8, which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus

  2. Composite axilens-axicon diffractive optical elements for generation of ring patterns with high focal depth

    Science.gov (United States)

    Dharmavarapu, Raghu; Vijayakumar, A.; Brunner, R.; Bhattacharya, Shanti

    2016-03-01

    A binary Fresnel Zone Axilens (FZA) is designed for the infinite conjugate mode and the phase profile of a refractive axicon is combined with it to generate a composite Diffractive Optical Element (DOE). The FZA designed for two focal lengths generates a line focus along the propagation direction extending between the two focal planes. The ring pattern generated by the axicon is focused through this distance and the radius of the ring depends on the propagation distance. Hence, the radius of the focused ring pattern can be tuned, during the design process, within the two focal planes. The integration of the two functions was carried out by shifting the location of zones of FZA with respect to the phase profile of the refractive axicon resulting in a binary composite DOE. The FZAs and axicons were designed for different focal depth values and base angles respectively, in order to achieve different ring radii within the focal depth of each element. The elements were simulated using scalar diffraction formula and their focusing characteristics were analyzed. The DOEs were fabricated using electron beam direct writing and evaluated using a fiber coupled diode laser. The tunable ring patterns generated by the DOEs have prospective applications in microdrilling as well as microfabrication of circular diffractive and refractive optical elements.

  3. Walking Pattern Generation of Dual-Arm Mobile Robot Using Preview Controller

    Directory of Open Access Journals (Sweden)

    P. Wu

    2012-09-01

    Full Text Available Based on the stability request of robot’s moving on the ground, the motion planning of dual-arm mobile robot when moving on the ground is studied and the preview control system is applied in the robot walking pattern generation. Direct question of robot kinematics in the extended task space is analyzed according to Degrees of Freedom configuration of the dual-arm mobile robot. It is proved that the preview control system could be used in the generation of robot Center of Mass forward trajectory through the building of double linear inverted pendulum model of dual-arm mobile robot. The sector gridding search algorithm is proposed and the reachable workspace which meets the Zero Moment Point stability principle when the robot moving on the ground is obtained. Tip Trajectory is generated through polynomial interpolation. Each joint curve is calculated using MATLAB which is imported to virtual physical model. The feasibility of gait generation is verified.

  4. Water supply patterns in two agricultural areas of Central Germany under climate change conditions

    Directory of Open Access Journals (Sweden)

    M. H. Tölle

    2012-04-01

    Full Text Available Increasing emissions of greenhouse gases and increasing prices for fossil fuels have highlighted the demand for CO2 "neutral" renewable energy sources, e.g. short rotation forestry systems used for bioenergy. These systems might be vulnerable to changes in temperature, precipitation and occurrence of extreme weather events. To estimate success or failure of such short rotation coppices in a certain area we need regional climate projections and risk assessment. Changes of water supply patterns in two agriculturally extensively used regions in Central Germany (around Göttingen and Großfahner with different climate conditions but both in the temperate climate zone are explored. The study is carried out under present conditions as well as under projected climate change conditions (1971–2100 using A1B and B1 climate scenarios downscaled for Europe. Analysis of precipitation bias shows regional differences: a strong bias in Göttingen area and a weaker bias in the Großfahner area. A bias correction approach, Quantile mapping, is applied to the ensemble results for both areas for winter and summer seasons. By using quantile regression on the seasonal Standardized Precipitation Indices (SPIs as indicator for water supply conditions we found that precipitation is expected to increase in winter in all quantiles of the distribution for Göttingen area during the 21th century. Heavy precipitation is also expected to increase for Großfahner area suggesting a trend to wetter extremes in winter for the future. This winter precipitation increase could trigger runoff and soil erosion risk enhancing the severity of floods. Increasing winter availability of water could enhance local water supply in spring. For both areas no significant change in summer was found over the whole time period. Although the climate change signal of the SPI indicate mild dryer conditions in summer at the end of the 21st century which may trigger water shortage and

  5. Towards pattern generation and chaotic series prediction with photonic reservoir computers

    Science.gov (United States)

    Antonik, Piotr; Hermans, Michiel; Duport, François; Haelterman, Marc; Massar, Serge

    2016-03-01

    Reservoir Computing is a bio-inspired computing paradigm for processing time dependent signals that is particularly well suited for analog implementations. Our team has demonstrated several photonic reservoir computers with performance comparable to digital algorithms on a series of benchmark tasks such as channel equalisation and speech recognition. Recently, we showed that our opto-electronic reservoir computer could be trained online with a simple gradient descent algorithm programmed on an FPGA chip. This setup makes it in principle possible to feed the output signal back into the reservoir, and thus highly enrich the dynamics of the system. This will allow to tackle complex prediction tasks in hardware, such as pattern generation and chaotic and financial series prediction, which have so far only been studied in digital implementations. Here we report simulation results of our opto-electronic setup with an FPGA chip and output feedback applied to pattern generation and Mackey-Glass chaotic series prediction. The simulations take into account the major aspects of our experimental setup. We find that pattern generation can be easily implemented on the current setup with very good results. The Mackey-Glass series prediction task is more complex and requires a large reservoir and more elaborate training algorithm. With these adjustments promising result are obtained, and we now know what improvements are needed to match previously reported numerical results. These simulation results will serve as basis of comparison for experiments we will carry out in the coming months.

  6. Fast Lagrangian relaxation for constrained generation scheduling in a centralized electricity market

    International Nuclear Information System (INIS)

    This paper proposes a fast Lagrangian relaxation (FLR) for constrained generation scheduling (CGS) problem in a centralized electricity market. FLR minimizes the consumer payment rather than the total supply cost subject to the power balance, spinning reserve, transmission line, and generator operating constraints. FLR algorithm is improved by new initialization of Lagrangian multipliers and adaptive adjustment of Lagrangian multipliers. The adaptive subgradient method using high quality initial feasible multipliers requires much less number of iterations to converge, leading to a faster computational time. If congestion exists, the alleviating congestion index is proposed for congestion management. Finally, the unit decommitment is performed to prevent excessive spinning reserve. The FLR for CGS is tested on the 4 unit and the IEEE 24 bus reliability test systems. The proposed uniform electricity price results in a lower consumer payment than system marginal price based on uniformly fixed cost amortized allocation, non-uniform price, and electricity price incorporating side payment, leading to a lower electricity price. In addition, observations on objective functions, pricing scheme comparison and interpretation of Lagrangian multipliers are provided. (author)

  7. Pattern of non-obstetric infectious recto-vaginal fistula: a case series and literature review in Cameroon, Central Africa

    OpenAIRE

    Pierre Marie Tebeu; Roger Guy Michel Ekono; Jovanny Tsuala Fouogue; Gregory Ekane Halle; Joel Domgue Fokom; Charles Henry Rochat

    2016-01-01

    Background: Perineal infection is an uncommon cause of non-obstetrical recto-vaginal fistula (RVF) which is associated with HIV infection. Cameroon (Central Africa) is in the fistula belt but infectious RVFs have not yet been deeply studied in the country. We therefore sought to determine the pattern of non-obstetric infectious RVF in Cameroon. Methods: We carried out a cross-sectional and descriptive review of non-obstetric infectious RVFs managed at the Yaound and eacute; University Teac...

  8. NeuroPG: Open source software for optical pattern generation and data acquisition

    Directory of Open Access Journals (Sweden)

    Benjamin W. Avants

    2015-03-01

    Full Text Available Patterned illumination using a digital micromirror device (DMD is a powerful tool for optogenetics. Compared to a scanning laser, DMDs are inexpensive and can easily create complex illumination patterns. Combining these complex spatiotemporal illumination patterns with optogenetics allows DMD-equipped microscopes to probe neural circuits by selectively manipulating the activity of many individual cells or many subcellular regions at the same time. To use DMDs to study neural activity, scientists must develop specialized software to coordinate optical stimulation patterns with the acquisition of electrophysiological and fluorescence data. To meet this growing need we have developed an open source optical pattern generation software for neuroscience - NeuroPG - that combines, DMD control, sample visualization, and data acquisition in one application. Built on a MATLAB platform, NeuroPG can also process, analyze, and visualize data. The software is designed specifically for the Mightex Polygon400; however, as an open source package, NeuroPG can be modified to incorporate any data acquisition, imaging, or illumination equipment that is compatible with MATLAB’s Data Acquisition and Image Acquisition toolboxes.

  9. Variable resolution pattern generation for the Associative Memory of the ATLAS FTK project

    CERN Document Server

    Annovi, A; The ATLAS collaboration; Faulkner, G; Giannetti, P; Jiang, Z; Luongo, C; Pandini, C; Shochet, M; Tompkins, L; Volpi, G

    2013-01-01

    The Associative Memory (AM) chip is special device that allows to find coincidence patterns, or just patterns, between the incoming data in up to 8 parallel streams. The latest AM chip has been designed to receive silicon clusters generated in 8 layers of the ATLAS silicon detector sensor, to perform parallel track pattern matching at high rate and it will be the core of the FTK project. Data going through each of the busses are compared with a bank of patterns and AM chip looks for matches in each line, like commercial content addressable memory (CAM). The high density of hits expected in the ATLAS inner detector from 2015 put a challenge in the capability of the AM chip in rejecting random coincidences, requiring either an extremely high number of high precision patterns, with increasing costs and complexity of the system, or more flexible solutions. For this reason in the most recent prototype of the AM chip ternary cells have been added in the logic, allowing “don’t care” (DC) bits in the match. Hav...

  10. Australasian microtektites from the Central Indian Basin: Implications for ejecta distribution patterns

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    Microtektites belonging to the Australasian tektite strewn field have been recovered in one (SK-16/176) out of three cores examined from the Central Indian Basin. The microtektites have been identified based on their physical appearance...

  11. Patterns of illness in travelers visiting Mexico and Central America: the GeoSentinel experience

    OpenAIRE

    Flores-Figueroa, J; Okhuysen, P C; von Sonnenburg, F.; DuPont, H L; Libman, M D; Keystone, J S; Hale, D C; Burchard, G; Han, P V; Wilder-Smith, A.; Freedman, D O

    2011-01-01

    BACKGROUND: Mexico and Central America are important travel destinations for North American and European travelers. There is limited information on regional differences in travel related morbidity. METHODS: We describe the morbidity among 4779 ill travelers returned from Mexico and Central America who were evaluated at GeoSentinel network clinics during December 1996 to February 2010. RESULTS: The most frequent presenting syndromes included acute and chronic diarrhea, dermat...

  12. Fast oscillations during gasping and other non-eupneic respiratory behaviors: Clues to central pattern generation

    OpenAIRE

    Ghali, Michael George Zaki; Marchenko, Vitaliy

    2013-01-01

    The mammalian nervous system exhibits fast synchronous oscillations, which are especially prominent in respiratory-related nerve discharges. In the phrenic nerve, they include high- (HFO), medium- (MFO), and low-frequency (LFO) oscillations. Because motoneurons firing at HFO-related frequencies had never been recorded, an epiphenomenological mechanism for their existence had been posited. We have recently recorded phrenic motoneurons firing at HFO-related frequencies in unanesthetized decereb...

  13. An optogenetic investigation of the control and development of the spinal central pattern generator in zebrafish

    OpenAIRE

    Warp, Erica Kirsten

    2012-01-01

    The nervous system directly controls the muscles of the body, and thus, the behavior of the animal. An understanding of the neural circuits and cell types that mediate and control behavior would give us insight into the mechanisms by which the nervous system operates and would also contribute to the development of therapies and treatments for neurological disorders and diseases that result in locomotor deficits. Some behaviors are organized by constant voluntary drive, while others, which req...

  14. An Analog VLSI Model of Central Pattern Generation in the Leech

    OpenAIRE

    Siegel, Micah S

    1994-01-01

    I detail the design and construction of an analog VLSI model of the neural system responsible for swimming behaviors of the leech. Why the leech? The biological network is small and relatively well understood, and the silicon model can therefore span three levels of organization in the leech nervous system (neuron, ganglion, system); it represents one of the first comprehensive models of leech swimming operating in real-time. The circuit employs biophysically motivated analog neurons netwo...

  15. Generation of spatially periodic patterns by a mechanical instability: a mechanical alternative to the Turing model.

    Science.gov (United States)

    Harris, A K; Stopak, D; Warner, P

    1984-04-01

    We have studied the generation of spatial patterns created by mechanical (rather than chemical) instabilities. When dissociated fibroblasts are suspended in a gel of reprecipitated collagen, and the contraction of the gel as a whole is physically restrained by attachment of its margin to a glass fibre meshwork, then the effect of the fibroblasts' traction is to break up the cell-matrix mixture into a series of clumps or aggregations of cells and compressed matrix. These aggregations are interconnected by linear tracts of collagen fibres aligned under the tensile stress exerted by fibroblast traction. The patterns generated by this mechanical instability vary depending upon cell population density and other factors. Over a certain range of cell concentrations, this mechanical instability yields geometric patterns which resemble but are usually much less regular than the patterns which develop normally in the dermis of developing bird skin. We propose that an equivalent mechanical instability, occurring during the embryonic development of this skin, could be the cause not only of the clumping of dermal fibroblasts to form the feather papillae, but also of the alignment of collagen fibres into the characteristic polygonal network of fibre bundles - which interconnect these papillae and which presage the subsequent pattern of the dermal muscles serving to control feather movements. More generally, we suggest that this type of mechanical instability can serve the morphogenetic functions for which Turing's chemical instability and other reaction-diffusion systems have been proposed. Mechanical instabilities can create physical structures directly, in one step, in contrast to the two or more steps which would be required if positional information first had to be specified by chemical gradients and then only secondarily implemented in physical form. In addition, physical forces can act more quickly and at much longer range than can diffusing chemicals and can generate a

  16. A Novel Biped Pattern Generator Based on Extended ZMP and Extended Cart-table Model

    Directory of Open Access Journals (Sweden)

    Guangbin Sun

    2015-07-01

    Full Text Available This paper focuses on planning patterns for biped walking on complex terrains. Two problems are solved: ZMP (zero moment point cannot be used on uneven terrain, and the conventional cart-table model does not allow vertical CM (centre of mass motion. For the ZMP definition problem, we propose the extended ZMP (EZMP concept as an extension of ZMP to uneven terrains. It can be used to judge dynamic balance on universal terrains. We achieve a deeper insight into the connection and difference between ZMP and EZMP by adding different constraints. For the model problem, we extend the cart-table model by using a dynamic constraint instead of constant height constraint, which results in a mathematically symmetric set of three equations. In this way, the vertical motion is enabled and the resultant equations are still linear. Based on the extended ZMP concept and extended cart-table model, a biped pattern generator using triple preview controllers is constructed and implemented simultaneously to three dimensions. Using the proposed pattern generator, the Atlas robot is simulated. The simulation results show the robot can walk stably on rather complex terrains by accurately tracking extended ZMP.

  17. 3D Quaternary deformation pattern in the central Po Plain (Northern Italy)

    Science.gov (United States)

    Sileo, G.; Mueller, K.; Michetti, A. M.; Livio, F.; Berlusconi, A.; Carcano, C.; Rogledi, S.; Vittori, E.

    2009-04-01

    The Po Plain is a foredeep basin flanked by the two major and active orogens of the Italian Peninsula, the Alps to the North and the Apennines to the South. The basin has a quasi - triangular shape and grades longitudinally to the East in the Adriatic Sea. We used petroleum industry seismic reflection data acquired by ENI E&P in the Central Po Plain, over an area spanning about 6800 km2 from Lake Como to the W to Lake Garda to the E, and from the Lombardian Southern Alps to the N and the Emilia Apennines to the S, in order to analyze and interpret selected seismic reflectors and to define the evolution in space and time of the local active tectonic structures. Folds associated with underlying thrusts were recognized based on deformation recorded by two regional sequence boundary horizons, i.e. the ‘A' Surface (1.6 Myr) and the ‘R' Surface (0. 9 Myr; e.g., Carcano & Piccin, 2002; Muttoni et al., 2003), characterized by good stratigraphic and age bracketing, and marking significant changes in the sedimentary architecture of the Po Basin. Age controls are based on stratigraphic, paleontological and magnetostratigraphic analysis by ENI E&P and Regione Lombardia (Carcano & Piccin, 2002; Scardia et al., 2006). The analysis of strain recorded by these horizons allowed us to: A) recognize a belt of active fold and thrust structures, each 10 to 20 km long, arranged with an en-echelon pattern across the whole Po Basin, and B) analyze their evolution over the Quaternary. 'A' surface (1.6 Myr) The ‘A' surface has been mapped over about 7800 Km2. From North to South four major morphobathymetric domains can be defined in the Pleistocene marine Po Basin: an Alpine platform domain, a slope that links it with the wider central basin domain, a smaller and steeper slope and an Apennine platform domain. The basin shape has an asymmetric transversal profile and is ca. 40 km wide. Several tectonic structures affect this surface. On the Alpine platform domain two small structures

  18. The TMAO-Generating Enzyme Flavin Monooxygenase 3 Is a Central Regulator of Cholesterol Balance

    Directory of Open Access Journals (Sweden)

    Manya Warrier

    2015-01-01

    Full Text Available Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide (TMAO have recently been linked to cardiovascular disease (CVD risk. Here, we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3 as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic endoplasmic reticulum (ER stress and inflammation in part by decreasing hepatic oxysterol levels and subsequent LXR activation. FMO3 is thus identified as a central integrator of hepatic cholesterol and triacylglycerol metabolism, inflammation, and ER stress. These studies suggest that the gut microbiota-driven TMA/FMO3/TMAO pathway is a key regulator of lipid metabolism and inflammation.

  19. Fluid power network for centralized electricity generation in offshore wind farms

    Science.gov (United States)

    Jarquin-Laguna, A.

    2014-06-01

    An innovative and completely different wind-energy conversion system is studied where a centralized electricity generation within a wind farm is proposed by means of a hydraulic network. This paper presents the dynamic interaction of two turbines when they are coupled to the same hydraulic network. Due to the stochastic nature of the wind and wake interaction effects between turbines, the operating parameters (i.e. pitch angle, rotor speed) of each turbine are different. Time domain simulations, including the main turbine dynamics and laminar transient flow in pipelines, are used to evaluate the efficiency and rotor speed stability of the hydraulic system. It is shown that a passive control of the rotor speed, as proposed in previous work for a single hydraulic turbine, has strong limitations in terms of performance for more than one turbine coupled to the same hydraulic network. It is concluded that in order to connect several turbines, a passive control strategy of the rotor speed is not sufficient and a hydraulic network with constant pressure is suggested. However, a constant pressure network requires the addition of active control at the hydraulic motors and spear valves, increasing the complexity of the initial concept. Further work needs to be done to incorporate an active control strategy and evaluate the feasibility of the constant pressure hydraulic network.

  20. Quantum properties of transverse pattern formation in second-harmonic generation

    DEFF Research Database (Denmark)

    Bache, Morten; Scotto, P.; Zambrini, R.;

    2002-01-01

    transverse wave number, which are not identified in a linearized analysis, are also described. The intensity differences between opposite points of the far fields are shown to exhibit sub-Poissonian statistics, revealing the quantum nature of the correlations. We observe twin beam correlations in both......We investigate the spatial quantum noise properties of the one-dimensional transverse pattern formation instability in intracavity second-harmonic generation. The Q representation of a quasi-probability distribution is implemented in terms of nonlinear stochastic Langevin equations. We study...... for pattern formation, beams with opposite direction of the off-axis critical wave numbers are shown to be highly correlated. This is observed for the fundamental field, for the second-harmonic field, and also for the cross-correlation between the two fields. Nonlinear correlations involving the homogeneous...

  1. Reduced Test Pattern Generation of Multiple SIC Vectors with Input and Output Delay Faults

    Directory of Open Access Journals (Sweden)

    P.T.Sairam

    2014-11-01

    Full Text Available In recent years, the design for low power has become one of the greatest challenges in high-performance very large scale integration (VLSI design. Most of the methods focus on the power consumption during normal mode operation, while test mode operation has not normally been a predominant concern. However, it has been found that the power consumed during test mode operation is often much higher than during normal mode operation [1]. This is because most of the consumed power results from the switching activity in the nodes of the circuit under test (CUT, which is much higher during test mode than during normal mode operation [1]–[3]. In the proposed pattern, each generated vector applied to each scan chain is an SIC vector, which can minimize the input transition and reduce test power. In VLSI testing, power reduction is achieved by increasing the correlation between consecutive test patterns.

  2. Coherence of light and generation of speckle patterns in photobiology and photomedicine

    Science.gov (United States)

    Zalevsky, Zeev; Belkin, Michael

    2012-03-01

    The use of diodes instead of lasers was recently suggested for phototherapeutic applications. This trend is due to economical and practical reasons and is based on the argument that lasers have no preference over diodes as light sources as the former lose their coherency upon penetrating biological tissues. This module supports this claim while providing a brief explanation to non professionals on the meaning of coherence of light as well as the physics behind the generation of speckle patterns, and the relation of these physical entities to photomedicine.

  3. DNA Image Pro -- A Tool for Generating Pixel Patterns using DNA Tile Assembly

    OpenAIRE

    Limbachiya, Dixita; Trivedi, Dhaval; Gupta, Manish K.

    2016-01-01

    Self-assembly is a process found everywhere in the Nature. In particular, it is known that DNA self-assembly is Turing universal. Thus one can do arbitrary computations or build nano-structures using DNA self-assembly. In order to understand the DNA self-assembly process, many mathematical models have been proposed in the literature. In particular, abstract Tile Assembly Model (aTAM) received much attention. In this work, we investigate pixel pattern generation using aTAM. For a given image, ...

  4. Supervised Generative Reconstruction: An Efficient Way To Flexibly Store and Recognize Patterns

    CERN Document Server

    Achler, Tsvi

    2011-01-01

    Matching animal-like flexibility in recognition and the ability to quickly incorporate new information remains difficult. Limits are yet to be adequately addressed in neural models and recognition algorithms. This work proposes a configuration for recognition that maintains the same function of conventional algorithms but avoids combinatorial problems. Feedforward recognition algorithms such as classical artificial neural networks and machine learning algorithms are known to be subject to catastrophic interference and forgetting. Modifying or learning new information (associations between patterns and labels) causes loss of previously learned information. I demonstrate using mathematical analysis how supervised generative models, with feedforward and feedback connections, can emulate feedforward algorithms yet avoid catastrophic interference and forgetting. Learned information in generative models is stored in a more intuitive form that represents the fixed points or solutions of the network and moreover disp...

  5. HIGH QUALITY IMPLEMENTATION FOR AUTOMATIC GENERATION C# CODE BY EVENT-B PATTERN

    Directory of Open Access Journals (Sweden)

    Eman K Elsayed

    2014-01-01

    Full Text Available In this paper we proposed the logical correct path to implement automatically any algorithm or model in verified C# code. Our proposal depends on using the event-B as a formal method. It is suitable solution for un-experience in programming language and profession in mathematical modeling. Our proposal also integrates requirements, codes and verification in system development life cycle. We suggest also using event-B pattern. Our suggestion is classify into two cases, the algorithm case and the model case. The benefits of our proposal are reducing the prove effort, reusability, increasing the automation degree and generate high quality code. In this paper we applied and discussed the three phases of automatic code generation philosophy on two case studies the first is “minimum algorithm” and the second one is a model for ATM.

  6. The repair of an electric generator at the Patla hydro central; Reparacion de un generador de la central hidroelectrica de Patla

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Hernandez, Roman [Luz y Fuerza del Centro, Mexico, D. F. (Mexico)

    1997-12-31

    This document describes the repair of the Generator Number 1 of the system of the Unit No. 1 of the Patla Hydro Power Central in Mexico. The tests that were conducted to determine the fault and the location of the same are shown. Mention is made of the fault repair options and the stages in one of the options are described, since it is the one that better covers the expectations for the satisfactory repair of the generator. Finally the commissioning test is described and it is concluded that an increment of 92% (14 MW) in the generation capacity of the unit was achieved, being this the first time a repair of this type is made of generating units [Espanol] Este documento describe la reparacion del generador numero 1 del sistema de la unidad numero 1 de la central hidroelectrica de Patla en Mexico. Se muestran las pruebas que se hicieron para determinar la falla y localizacion de la misma. Se mencionan las alternativas de reparacion de la falla y se describen las etapas de una de las alternativas, ya que es la que cubre mejor las expectativas para la reparacion satisfactoria del generador. Por ultimo se describe la prueba de puesta en servicio y se concluye en que se logro un aumento de la capacidad de generacion de la unidad en un 92% (14 MW), siendo la primera vez que se hace una reparacion de este tipo de unidades generadoras

  7. A RANDOM FUNCTIONAL CENTRAL LIMIT THEOREM FOR PROCESSES OF PRODUCT SUMS OF LINEAR PROCESSES GENERATED BY MARTINGALE DIFFERENCES

    Institute of Scientific and Technical Information of China (English)

    WANG YUEBAO; YANG YANG; ZHOU HAIYANG

    2003-01-01

    A random functional central limit theorem is obtained for processes of partial sums andproduct sums of linear processes generated by non-stationary martingale differences. It devel-ops and improves some corresponding results on processes of partial sums of linear processesgenerated by strictly stationary martingale differences, which can be found in [5].

  8. Low frequency variability of European weather patterns and its impact on power generation in northern Europe

    Science.gov (United States)

    Masato, Giacomo; Slavov, Georgi

    2016-04-01

    It is well known that Europe is becoming increasingly reliant on the power generation from the solar and wind sources. Germany is a leader in such a trend - it is then interesting to study to what extent the low-frequency variability of the European weather patterns impacts the power production in this country. Rather than identifying such patterns starting from the weather angle, four weather regimes are identified that maximize and minimize the production of solar and wind power. The analysis of their past occurrence and trends allows us to estimate the potential amount of energy produced for any given year (assuming a constant installed capacity). It is found that the sole change in such weather regimes over the recent years is able to drive up to a 20% annual difference in power generation. This also throws an interesting challenge at the scientific community, whereby the future projection of these regimes can heavily influence both the short- and long-term Eurozone plans in terms of European renewable energy targets.

  9. Endogenous rhythm and pattern-generating circuit interactions in cockroach motor centres

    Directory of Open Access Journals (Sweden)

    Izhak David

    2016-09-01

    Full Text Available Cockroaches are rapid and stable runners whose gaits emerge from the intricate, and not fully resolved, interplay between endogenous oscillatory pattern-generating networks and sensory feedback that shapes their rhythmic output. Here we studied the endogenous motor output of a brainless, deafferented preparation. We monitored the pilocarpine-induced rhythmic activity of levator and depressor motor neurons in the mesothoracic and metathoracic segments in order to reveal the oscillatory networks’ architecture and interactions. Data analyses included phase relations, latencies between and overlaps of rhythmic bursts, spike frequencies, and the dependence of these parameters on cycle frequency. We found that, overall, ipsilateral connections are stronger than contralateral ones. Our findings revealed asymmetries in connectivity among the different ganglia, in which meta-to-mesothoracic ascending coupling is stronger than meso-to-metathoracic descending coupling. Within-ganglion coupling between the metathoracic hemiganglia is stronger than that in the mesothoracic ganglion. We also report differences in the role and mode of operation of homologue network units (manifested by levator and depressor nerve activity. Many observed characteristics are similar to those exhibited by intact animals, suggesting a dominant role for feedforward control in cockroach locomotion. Based on these data we posit a connectivity scheme among components of the locomotion pattern generating system.

  10. Analysis of Soil Heavy Metal Pollution and Pattern in Central Transylvania

    OpenAIRE

    Lorentz Jäntschi; Sorana D. Bolboacă; Mihai Todică; Constantin Cosma; Ioan Suciu

    2008-01-01

    The concentration of five soil heavy metals (Pb, Co, Cr, Cu, Hg) was measured in forty sampling sites in central Transylvania, Romania, regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using the Inductively Coupled Plasma Spectrometry method. Data were verified by using the Neu...

  11. Legume Diversity Patterns in West Central Africa: Influence of Species Biology on Distribution Models

    OpenAIRE

    Manuel de la Estrella; Mateo, Rubén G.; Wieringa, Jan J.; Barbara Mackinder; Jesús Muñoz

    2012-01-01

    OBJECTIVES: Species Distribution Models (SDMs) are used to produce predictions of potential Leguminosae diversity in West Central Africa. Those predictions are evaluated subsequently using expert opinion. The established methodology of combining all SDMs is refined to assess species diversity within five defined vegetation types. Potential species diversity is thus predicted for each vegetation type respectively. The primary aim of the new methodology is to define, in more detail, areas of sp...

  12. Permission of change of limits in the vapor generators of the Atucha I Nuclear Central

    International Nuclear Information System (INIS)

    In the mark of the modification of the Atucha-I Nuclear Central Installation (CNA-I) as consequence of the Introduction of the System 'Second Drain of Heat' (SSC), the Entity Responsible for the CNA-I (NASA) requested authorization to the Nuclear Regulatory Authority (ARN) to modify the value of the minimum level of water in the secondary side in the Steam generators (GVs) to activate the signal 'shoot of the Cut of the Reactor' (RESA-LLV). As the level in the GVs is one of those parameters that are used to shoot the Emergency Feeding System (RX), component of the SSC System, also was analyzed the change in the activation of the shoot signal of the 'Second Drain of Heat' (2SSC-LLV). The ARN uses for the study of the nuclear safety of nuclear power plants, the series of prediction programs RELAP5/MOD3.X. It participates of the evaluation and maintenance activities of these codes through specific agreements with the U.S. Nuclear Regulatory Commission (US-NRC). It is necessary to account with programs of this type since the ARN it licenses the construction and operation of Nuclear Power Plants (NPPs) and other outstanding facilities and it inquires its operation according to its own standards. With these tools its are auditing the calculations that the Responsible Entities of the operation make to guarantee the operability of the NPPs assisting the mentioned standards. The analysis with computational codes is used as a tool to achieve the best understanding in the behavior of the plant in union with the engineering approach, the manual calculations, the data analysis and the experience in the operation of the machine. (Author)

  13. Central Cell-Derived Peptides Regulate Early Embryo Patterning in Flowering Plants

    NARCIS (Netherlands)

    Costa, L.M.; Marshall, E.; Tesfaye, M.; Silverstein, K.A.T.; Mori, M.; Umetsu, Y.; Otterbach, S.L.; Papareddy, R.; Dickinson, H.G.; Boutilier, K.A.; VandenBosch, K.A.; Ohki, S.; Gutierrez-Marcos, J.F.

    2014-01-01

    Plant embryogenesis initiates with the establishment of an apical-basal axis; however, the molecular mechanisms accompanying this early event remain unclear. Here, we show that a small cysteine-rich peptide family is required for formation of the zygotic basal cell lineage and proembryo patterning i

  14. Resolution Improvement and Pattern Generator Development for the Maskless Micro-Ion-Beam Reduction Lithography System

    International Nuclear Information System (INIS)

    have been studied. The dependence of the throughput with the exposure field size and the speed of the mechanical stage has been investigated. In order to perform maskless lithography, different micro-fabricated pattern generators have been developed for the MMRL system. Ion beamlet switching has been successfully demonstrated on the MMRL system. A positive bias voltage around 10 volts is sufficient to switch off the ion current on the micro-fabricated pattern generators. Some unexpected problems, such as the high-energy secondary electron radiations, have been discovered during the experimental investigation. Thermal and structural analysis indicates that the aperture displacement error induced by thermal expansion can satisfy the 3(delta) CD requirement for lithography nodes down to 25 nm. The cross-talking effect near the surface and inside the apertures of the pattern generator has been simulated in a 3-D ray-tracing code. New pattern generator design has been proposed to reduce the cross-talking effect. In order to eliminate the surface charging effect caused by the secondary electrons, a new beam-switching scheme in which the switching electrodes are immersed in the plasma has been demonstrated on a mechanically fabricated pattern generator

  15. Controlling the magnetic field distribution on the micrometer scale and generation of magnetic bead patterns for microfluidic applications.

    Science.gov (United States)

    Yu, Xu; Feng, Xuan; Hu, Jun; Zhang, Zhi-Ling; Pang, Dai-Wen

    2011-04-19

    As is well known, controlling the local magnetic field distribution on the micrometer scale in a microfluidic chip is significant and has many applications in bioanalysis based on magnetic beads. However, it is a challenge to tailor the magnetic field introduced by external permanent magnets or electromagnets on the micrometer scale. Here, we demonstrated a simple approach to controlling the local magnetic field distribution on the micrometer scale in a microfluidic chip by nickel patterns encapsulated in a thin poly(dimethylsiloxane) (PDMS) film under the fluid channel. With the precisely controlled magnetic field, magnetic bead patterns were convenient to generate. Moreover, two kinds of fluorescent magnetic beads were patterned in the microfluidic channel, which demonstrated that it was possible to generate different functional magnetic bead patterns in situ, and could be used for the detection of multiple targets. In addition, this method was applied to generate cancer cell patterns.

  16. Optimisation of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    DEFF Research Database (Denmark)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    Central receiver solar thermal power plants are regarded as one of the promising ways to generate electricity in near future. They offer the possibility of using high temperatures and pressures to achieve high efficiencies with standard power cycles. A direct steam generation approach can be used...... for such plants for improved performance. This approach can also be combined with using advanced power cycles like the Kalina cycle, which uses a zeotropic mixture of ammonia and water instead of pure water as the working fluid. This paper presents the optimisation of a particular Kalina cycle layout...... for a central receiver solar thermal power plant with direct steam generation. The variation in the cycle performance with respect to the turbine inlet ammonia mass fraction and pressure and a comparison of the initial investment with that of the basic Rankine cycle are also presented. Only high live steam...

  17. Altitudinal Pattern of Plant Species Diversity in Shennongjia Mountains, Central China

    Institute of Scientific and Technical Information of China (English)

    Chang-Ming ZHAO; Wei-Lie CHEN; Zi-Qiang TIAN; Zong-Qiang XIE

    2005-01-01

    One hundred and sixty plots, approximately every 100 m above sea level (a.s.l.) along an altitudinal gradient from 470 to 3 080 m a.s.l, at the southern and northern watershed of Mt. Shennongjia,China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis (DCCA) based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the "mid-altitude bulge" was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone (900-1 500 m a.s.l.) and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.l. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.l., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt.Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a

  18. Mosquito biodiversity patterns around urban environments in South-central okinawa island, Japan.

    Science.gov (United States)

    Hoshi, Tomonori; Imanishi, Nozomi; Higa, Yukiko; Chaves, Luis Fernando

    2014-12-01

    Okinawa is the largest, most urbanized, and densely populated island in the Ryukyus Archipelago, where mosquito species diversity has been thoroughly studied. However, the south-central Okinawa mosquito fauna has been relatively poorly studied. Here, we present results from a mosquito faunal survey in urban environments of Nishihara city, south-central Okinawa. Mosquitoes were sampled biweekly, from April 2007 to March 2008, at 3 different environments: a forest preserve, an animal farm, and a water reservoir. We employed 4 mosquito collection methods: 1) oviposition traps; 2) light traps; 3) sweep nets; and 4) larval surveys of tree holes, leaf axils, and artificial water containers. We collected a total of 568 adults and 10,270 larvae belonging to 6 genera and 13 species, including 6 species of medical importance: Aedes albopictus, Armigeres subalbatus, Anopheles Hyrcanus group, Culex bitaeniorhynchus, Cx. quinquefasciatus, and Cx. tritaeniorhynchus. Mosquito species composition was similar to data from previous studies in Okinawa Island. The flattening of the species accumulation curve suggests that our diversity sampling was exhaustive with light and oviposition traps, as well as the coincidence between the species richness we found in the field and estimates from the Chao2 index, a theoretical estimator of species richness based on species abundance. This study highlights the importance of combining several sampling techniques to properly characterize regional mosquito fauna and to monitor changes in the presence of mosquito species.

  19. Pattern of Maxillofacial fracture in Western and Central Nepal: An experience in 3 tertiary level health institutions

    Directory of Open Access Journals (Sweden)

    S Subedi

    2015-06-01

    Full Text Available BACKGROUND: There are only few studies regarding the pattern and causes of maxillofacial fractures till date in Nepal and no such study in western and central Nepalese population has been conducted. The purpose of this study, therefore, was to describe the causes and the pattern of maxillofacial fractures in western and central part of Nepal over the period of 5 years. MATERIAL AND METHODS A retrospective analysis of maxillofacial fractures was conducted on 328 patients who were treated in the department of maxillofacial surgery. Data was extracted and analyzed based on age, sex, cause of injury and anatomic location. RESULT Young males of 3rd decade of life most commonly sustained the maxillofacial trauma. The commonest site involved was the zygomatic complex (42% when only mid face fractures was considered and parasymphysis (32% when only mandible was considered.The most common cause of injuries was road traffic accidents (289 patients; 88.1% followed by interpersonal violence (25 patients; 7.6 % and falls accounting for 4.2% of the all injuries. CONCLUSION The findings of this study suggest the need for expansion of the motorway network, ensuring compliance of strict traffic rules and regulations, replacing old vehicles without safety measures and implement school education in alcohol abuse.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12771 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 8-13

  20. Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation

    OpenAIRE

    G.S. Souza; H.B. Schakelford; Moura, A.L.A.; Gomes, B.D.; D.F. Ventura; M.E.C. Fitzgerald; L.C.L. Silveira

    2012-01-01

    This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean lu...

  1. Association between atmospheric circulation patterns and firn-ice core records from the Inilchek glacierized area, central Tien Shan, Asia

    Science.gov (United States)

    Aizen, V.B.; Aizen, E.M.; Melack, J.M.; Kreutz, K.J.; Cecil, L.D.

    2004-01-01

    Glacioclimatological research in the central Tien Shan was performed in the summers of 1998 and 1999 on the South Inilchek Glacier at 5100-5460 m. A 14.36 m firn-ice core and snow samples were collected and used for stratigraphic, isotopic, and chemical analyses. The firn-ice core and snow records were related to snow pit measurements at an event scale and to meteorological data and synoptic indices of atmospheric circulation at annual and seasonal scales. Linear relationships between the seasonal air temperature and seasonal isotopic composition in accumulated precipitation were established. Changes in the ??18O air temperature relationship, in major ion concentration and in the ratios between chemical species, were used to identify different sources of moisture and investigate changes in atmospheric circulation patterns. Precipitation over the central Tien Shan is characterized by the lowest ionic content among the Tien Shan glaciers and indicates its mainly marine origin. In seasons of minimum precipitation, autumn and winter, water vapor was derived from the and and semiarid regions in central Eurasia and contributed annual maximal solute content to snow accumulation in Tien Shan. The lowest content of major ions was observed in spring and summer layers, which represent maximum seasonal accumulation when moisture originates over the Atlantic Ocean and Mediterranean and Black Seas. Copyright 2004 by the American Geophysical Union.

  2. Differential roles for EphA and EphB signaling in segregation and patterning of central vestibulocochlear nerve projections.

    Directory of Open Access Journals (Sweden)

    Michelle R Allen-Sharpley

    Full Text Available Auditory and vestibular afferents enter the brainstem through the VIIIth cranial nerve and find targets in distinct brain regions. We previously reported that the axon guidance molecules EphA4 and EphB2 have largely complementary expression patterns in the developing avian VIIIth nerve. Here, we tested whether inhibition of Eph signaling alters central targeting of VIIIth nerve axons. We first identified the central compartments through which auditory and vestibular axons travel. We then manipulated Eph-ephrin signaling using pharmacological inhibition of Eph receptors and in ovo electroporation to misexpress EphA4 and EphB2. Anterograde labeling of auditory afferents showed that inhibition of Eph signaling did not misroute axons to non-auditory target regions. Similarly, we did not find vestibular axons within auditory projection regions. However, we found that pharmacologic inhibition of Eph receptors reduced the volume of the vestibular projection compartment. Inhibition of EphB signaling alone did not affect auditory or vestibular central projection volumes, but it significantly increased the area of the auditory sensory epithelium. Misexpression of EphA4 and EphB2 in VIIIth nerve axons resulted in a significant shift of dorsoventral spacing between the axon tracts, suggesting a cell-autonomous role for the partitioning of projection areas along this axis. Cochlear ganglion volumes did not differ among treatment groups, indicating the changes seen were not due to a gain or loss of cochlear ganglion cells. These results suggest that Eph-ephrin signaling does not specify auditory versus vestibular targets but rather contributes to formation of boundaries for patterning of inner ear projections in the hindbrain.

  3. Spatial pattern and weight of seabed marine litter in the northern and central Adriatic Sea.

    Science.gov (United States)

    Strafella, P; Fabi, G; Spagnolo, A; Grati, F; Polidori, P; Punzo, E; Fortibuoni, T; Marceta, B; Raicevich, S; Cvitkovic, I; Despalatovic, M; Scarcella, G

    2015-02-15

    The present study analyzes spatial distribution and typology of marine litter on the seabed in the FAO Geographical Sub-Area 17 (northern and central Adriatic Sea). Two surveys were conducted during fall 2011 and 2012 and 67 stations were sampled each year. Litter items were collected using the "rapido" trawl, a modified beam trawl commonly used by the Italian fishermen to catch flat fish and other benthic species. Marine litter in the catches was sorted and classified in 6 major categories (plastic, metal, glass, rubber, wood, other). Plastic litter was further subdivided in 3 sub-categories based on its source: fishing nets, aquaculture nets and other. Plastic was dominant in terms of weight followed by metal and other categories. The highest concentration of litter was found close to the coast likely as a consequence of high coastal urbanization, river inflow and extensive navigation associated with the morphological and hydrological features of the basin. PMID:25560999

  4. Marketing patterns of agricultural commodities in an upland area of Central Java

    Directory of Open Access Journals (Sweden)

    Caroline M. van Ommeren

    2013-07-01

    Full Text Available In the uplands of Central Java a wide variety of dry cultivated crops are produced for subsistence as well as for cash. The marketing channels for these crops are also diverse. The producers can choose between selling at the market place or at their farms; either to consumers or traders; or they can sell their products to wholesalers in the towns. However, this freedom of choice is not absolute and is determined by the quantity of the merchandise. Farmers/who can sell large amounts of produce are able to bypass some steps in the hierarchical order of market places or traders. Thus, producers with relatively large farmlands can sell their commodities in more profitable ways compared to those with /smaller farms. Moreover, the latter are often forced to sell their produce below market value to traders who provided them with advance or who bought the crop before harvest (tebasan, because of their need for cash

  5. Energy Pattern Generator; Understanding the effect of user behaviour on energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Paauw, J.; Roossien, B. [ECN Efficiency and Infrastructure, Petten (Netherlands); Aries, M.B.C. [TNO Built Environment and Geosciences, Delft (Netherlands); Guerra Santin, O. [OTB Research Institute for Housing, Urban and Mobility Studies, Delft University of Technology, Delft (Netherlands)

    2009-11-15

    To understand and research the effect of user behaviour on energy performance, an Energy Pattern Generator (EPG) is being developed. This software tool produces high resolution electricity and heat demand patterns for five different household types. In addition, energy consumption is related to five common types of dwellings in the Netherlands. Input for the EPG is provided by measured energy demand profiles of common household appliances and statistical data from time-of-use surveys. Internal heat gains due to appliances play an important role in the energy balance of energy efficient buildings. These gains are however often simplified in today's tools into (at best) fixed weekly schedules. The EPG provides a more realistic representation of (the variation in) occupant behaviour. Varying internal gains are calculated for several user profiles, based on variations in the use of domestic appliances and the household occupancy by the residents. Using the EPG as a 'plug-in', building simulation can determine whether new building concepts are 'user proof'. The EPG is also of importance in the design of (intelligent) electricity grids as it provides dynamics in the grid's loads. The EPG provides insight in actual loads which can be scaled up to i.e. district level.

  6. Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy.

    Science.gov (United States)

    Eldridge, Tilly; Łangowski, Łukasz; Stacey, Nicola; Jantzen, Friederike; Moubayidin, Laila; Sicard, Adrien; Southam, Paul; Kennaway, Richard; Lenhard, Michael; Coen, Enrico S; Østergaard, Lars

    2016-09-15

    Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue-level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity. PMID:27624834

  7. Technological solutions of decentralized generation of hydroelectricity for those demands that cannot be attended by conventional electric with centralized generation

    Energy Technology Data Exchange (ETDEWEB)

    Signoretti, Valdir Tesche; Veras, Carlos Alberto Gurgel Rudi; Els, Henri Van [Universidade de Brasilia, Brasilia, DF (Brazil). Faculdade de Tecnologia. Dept. de Engenharia Mecanica], e-mail: gurgel@unb.br

    2010-07-01

    A source of energy stable and reliable and of acceptable cost is a basic requisite for the development of a given region can give-if full. Access to energy is important basis of human existence, essential to the satisfaction of basic needs such as food, clothing, and housing and also of mobility and communication. However, the dependency world burning of fossil fuels for energy generation and supply of a demand constantly increasing, both in industrialized countries and those in development, already threatening the ecological stability of the Earth. At the same time, conflicts by distribution of the last reserves these resources non-renewable threaten significantly to civil society. Adding to the breakneck speed in which humanity consumes the energetic sources and the obvious devastation of nature has an unequal distribution in consumption and access to energy. Renewable sources and energy efficiency are viable and necessary, especially because they can be the key to reduce wastefulness and extend the access to energy. In this way, there is a significant influence on economic and social inclusion of population excluded, generating employment and income with costs local and global environmental reduced compared to traditional forms and unsustainable generation and use of energy. This work is a study involving issues related to rural electrification from hydroelectricity, especially related to those isolated communities of the Amazon region that are lacking this form of energy, presented a general review since the origins of hydroelectricity in Brazil, as well as a national panorama electric exclusion as well as a scenario Amazon's supply of electricity. Finally presenting-if the main technologies available for hydroelectric generation for these isolated communities. (author)

  8. Automatic test pattern generation for stuck-at and delay faults in combinational circuits

    International Nuclear Information System (INIS)

    The present studies are developed to propose the automatic test pattern generation (ATG) algorithms for combinational circuits. These ATG algorithms are realized in two ATG programs: One is the ATG program for stuck-at fault and the other one for delay faults. In order to accelerate the ATG process, these two ATG programs have a common feature (the search method based on the concept of the degree of freedom), whereas only ATG program for the delay fault utilizes the 19-valued logic, a type of composite valued logic. This difference between two ATG programs results from the difference of the target fault. Accelerating the ATG process is indispensable for improving the ATG algorithms. This acceleration is mainly achieved by reducing the number of the unnecessary backtrackings, making the earlier detection of the conflicts, and shortening the computation time between the implication. Because of this purpose, the developed ATG programs include the new search method based on the concept of the degree of freedom (DF). The DF concept, computed directly and easily from the system descriptions such as types of gates and their interconnections, is the criterion to decide which, among several alternate lines' logic values required along each path, promises to be the most effective in order to accelerate and improve the ATG process. This DF concept is utilized to develop and improve both of ATG programs for stuck-at and delay faults in combinational circuits. In addition to improving the ATG process, reducing number of test pattern is indispensable for testing the delay faults because the size of the delay faults grows rapidly as increasing the size of the circuit. In order to improve the compactness of the test set, 19-valued logic are derived. Unlike other TG logic systems, 19-valued logic is utilized to generate the robustly hazard-free test pattern. This is achieved by using the basic 5-valued logic, proposed in this work, where the transition with no hazard is

  9. Congruent phylogeographical patterns of eight tree species in Atlantic Central Africa provide insights into the past dynamics of forest cover.

    Science.gov (United States)

    Dauby, G; Duminil, J; Heuertz, M; Koffi, G K; Stévart, T; Hardy, O J

    2014-05-01

    Cycles of Quaternary climatic change are assumed to be major drivers of African rainforest dynamics and evolution. However, most hypotheses on past vegetation dynamics relied on palaeobotanical records, an approach lacking spatial resolution, and on current patterns of species diversity and endemism, an approach confounding history and environmental determinism. In this context, a comparative phylogeographical study of rainforest species represents a complementary approach because Pleistocene climatic fluctuations may have left interpretable signatures in the patterns of genetic diversity within species. Using 1274 plastid DNA sequences from eight tree species (Afrostyrax kamerunensis, A. lepidophyllus, Erythrophleum suaveolens, Greenwayodendron suaveolens, Milicia excelsa, Santiria trimera, Scorodophloeus zenkeri and Symphonia globulifera) sampled in 50 populations of Atlantic Central Africa (ACA), we averaged divergence across species to produce the first map of the region synthesizing genetic distinctiveness and standardized divergence within and among localities. Significant congruence in divergence was detected mostly among five of the eight species and was stronger in the northern ACA. This pattern is compatible with a scenario of past forest fragmentation and recolonization whereby forests from eastern Cameroon and northeastern Gabon would have been more affected by past climatic change than those of western Cameroon (where one or more refugia would have occurred). By contrast, southern ACA (Gabon) displayed low congruence among species that may reflect less drastic past forest fragmentation or a more complex history of vegetation changes. Finally, we also highlight the potential impact of current environmental barriers on spatial genetic structures. PMID:24655106

  10. Habitat use and foraging patterns of molting male Long-tailed Ducks in lagoons of the central Beaufort Sea, Alaska

    Science.gov (United States)

    Flint, Paul L.; Reed, John; Deborah Lacroix,; Richard Lanctot,

    2016-01-01

    From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (Clangula hyemalis) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.

  11. Terrestrial movement patterns of western pond turtles (Actinemys marmorata) in central California

    Science.gov (United States)

    Pilliod, David S.; Welty, Justin L.; Stafford, Robert

    2013-01-01

    We used radio telemetry to track the terrestrial movements and seasonal habitat use patterns of Western Pond Turtles (Actinemys marmorata) near two ponds in the Carrizo Plain Ecological Reserve, California, USA. We captured 93 turtles in September 2005 and, of these, we tagged three males and six females(weighing > 300 g) with external transmitters. Tagged turtles traveled from 255–1,096 m over the 448-day study, and we found none further than 343 m from ponds. All turtles moved away from the ponds as water levels receded in the fall, resulting in periods of terrestrial overwintering ranging from 10–30 weeks (74–202 d). We found no evidence for group migrations as turtles departed ponds over 2–8 week periods, moved in different directions from their ponds, and used different habitats. Turtles overwintered mainly in oak and chaparral vegetation communities, which constituted most of the local vegetation. We found overwintering turtles in a variety of microhabitats, but all turtles were on the surface with their carapace just visible amongst the duff layer. Turtles returned to ponds over several weeks, sometimes months after they refilled with winter rains. In the winter of 2006–2007, no turtles returned to terrestrial overwintering sites used the previous year. Most of the turtles we tracked spent over half of each year on land, demonstrating the importance of terrestrial habitats around these seasonal ponds. This pattern is similar to pond turtles living in streams (overwinter on land), as compared to permanent ponds (turtles often remain in water).

  12. Patterns of preweaning diarrhea in piglets on a central California ranch.

    Science.gov (United States)

    Urcelay, S; Hird, D W; Huffman, E M; Parker, K; Farver, T B

    1984-10-01

    To determine risk factors for development of diarrhea in litters of preweaned piglets, data were analyzed from records of 4,397 litters of swine farrowed on a central California ranch 1978-1982. Sixty-four percent of litters were treated for diarrhea. Statistical analysis by multiple logistic regression showed that litters born to young sows (parity less than or equal to 2) were 1.7 times more likely to develop diarrhea before weaning than were litters born to older sows (parity greater than or equal to 3) and that litters born on one end of farrowing barns were 1.3 times more likely to develop diarrhea than were litters born in the other end. The association of diarrhea with other variables--dam breed, sire, gestation group, gestation length, size of litter, number of mummies, runts or stillbirths per litter, farrowing barn of birth or day of the week farrowed--was weak or nonexistent (P greater than 0.01).

  13. Nanophotonic reservoir computing with photonic crystal cavities to generate periodic patterns.

    Science.gov (United States)

    Fiers, Martin Andre Agnes; Van Vaerenbergh, Thomas; Wyffels, Francis; Verstraeten, David; Schrauwen, Benjamin; Dambre, Joni; Bienstman, Peter

    2014-02-01

    Reservoir computing (RC) is a technique in machine learning inspired by neural systems. RC has been used successfully to solve complex problems such as signal classification and signal generation. These systems are mainly implemented in software, and thereby they are limited in speed and power efficiency. Several optical and optoelectronic implementations have been demonstrated, in which the system has signals with an amplitude and phase. It is proven that these enrich the dynamics of the system, which is beneficial for the performance. In this paper, we introduce a novel optical architecture based on nanophotonic crystal cavities. This allows us to integrate many neurons on one chip, which, compared with other photonic solutions, closest resembles a classical neural network. Furthermore, the components are passive, which simplifies the design and reduces the power consumption. To assess the performance of this network, we train a photonic network to generate periodic patterns, using an alternative online learning rule called first-order reduced and corrected error. For this, we first train a classical hyperbolic tangent reservoir, but then we vary some of the properties to incorporate typical aspects of a photonics reservoir, such as the use of continuous-time versus discrete-time signals and the use of complex-valued versus real-valued signals. Then, the nanophotonic reservoir is simulated and we explore the role of relevant parameters such as the topology, the phases between the resonators, the number of nodes that are biased and the delay between the resonators. It is important that these parameters are chosen such that no strong self-oscillations occur. Finally, our results show that for a signal generation task a complex-valued, continuous-time nanophotonic reservoir outperforms a classical (i.e., discrete-time, real-valued) leaky hyperbolic tangent reservoir (normalized root-mean-square errors=0.030 versus NRMSE=0.127).

  14. Nanophotonic reservoir computing with photonic crystal cavities to generate periodic patterns.

    Science.gov (United States)

    Fiers, Martin Andre Agnes; Van Vaerenbergh, Thomas; Wyffels, Francis; Verstraeten, David; Schrauwen, Benjamin; Dambre, Joni; Bienstman, Peter

    2014-02-01

    Reservoir computing (RC) is a technique in machine learning inspired by neural systems. RC has been used successfully to solve complex problems such as signal classification and signal generation. These systems are mainly implemented in software, and thereby they are limited in speed and power efficiency. Several optical and optoelectronic implementations have been demonstrated, in which the system has signals with an amplitude and phase. It is proven that these enrich the dynamics of the system, which is beneficial for the performance. In this paper, we introduce a novel optical architecture based on nanophotonic crystal cavities. This allows us to integrate many neurons on one chip, which, compared with other photonic solutions, closest resembles a classical neural network. Furthermore, the components are passive, which simplifies the design and reduces the power consumption. To assess the performance of this network, we train a photonic network to generate periodic patterns, using an alternative online learning rule called first-order reduced and corrected error. For this, we first train a classical hyperbolic tangent reservoir, but then we vary some of the properties to incorporate typical aspects of a photonics reservoir, such as the use of continuous-time versus discrete-time signals and the use of complex-valued versus real-valued signals. Then, the nanophotonic reservoir is simulated and we explore the role of relevant parameters such as the topology, the phases between the resonators, the number of nodes that are biased and the delay between the resonators. It is important that these parameters are chosen such that no strong self-oscillations occur. Finally, our results show that for a signal generation task a complex-valued, continuous-time nanophotonic reservoir outperforms a classical (i.e., discrete-time, real-valued) leaky hyperbolic tangent reservoir (normalized root-mean-square errors=0.030 versus NRMSE=0.127). PMID:24807033

  15. Spatiotemporal patterns of fault slip rates across the Central Sierra Nevada frontal fault zone

    Science.gov (United States)

    Rood, Dylan H.; Burbank, Douglas W.; Finkel, Robert C.

    2011-01-01

    Patterns in fault slip rates through time and space are examined across the transition from the Sierra Nevada to the Eastern California Shear Zone-Walker Lane belt. At each of four sites along the eastern Sierra Nevada frontal fault zone between 38 and 39° N latitude, geomorphic markers, such as glacial moraines and outwash terraces, are displaced by a suite of range-front normal faults. Using geomorphic mapping, surveying, and 10Be surface exposure dating, mean fault slip rates are defined, and by utilizing markers of different ages (generally, ~ 20 ka and ~ 150 ka), rates through time and interactions among multiple faults are examined over 10 4-10 5 year timescales. At each site for which data are available for the last ~ 150 ky, mean slip rates across the Sierra Nevada frontal fault zone have probably not varied by more than a factor of two over time spans equal to half of the total time interval (~ 20 ky and ~ 150 ky timescales): 0.3 ± 0.1 mm year - 1 (mode and 95% CI) at both Buckeye Creek in the Bridgeport basin and Sonora Junction; and 0.4 + 0.3/-0.1 mm year - 1 along the West Fork of the Carson River at Woodfords. Data permit rates that are relatively constant over the time scales examined. In contrast, slip rates are highly variable in space over the last ~ 20 ky. Slip rates decrease by a factor of 3-5 northward over a distance of ~ 20 km between the northern Mono Basin (1.3 + 0.6/-0.3 mm year - 1 at Lundy Canyon site) to the Bridgeport Basin (0.3 ± 0.1 mm year - 1 ). The 3-fold decrease in the slip rate on the Sierra Nevada frontal fault zone northward from Mono Basin is indicative of a change in the character of faulting north of the Mina Deflection as extension is transferred eastward onto normal faults between the Sierra Nevada and Walker Lane belt. A compilation of regional deformation rates reveals that the spatial pattern of extension rates changes along strike of the Eastern California Shear Zone-Walker Lane belt. South of the Mina Deflection

  16. Diet-related buccal dental microwear patterns in Central African Pygmy foragers and Bantu-speaking farmer and pastoralist populations.

    Science.gov (United States)

    Romero, Alejandro; Ramírez-Rozzi, Fernando V; De Juan, Joaquín; Pérez-Pérez, Alejandro

    2013-01-01

    Pygmy hunter-gatherers from Central Africa have shared a network of socioeconomic interactions with non-Pygmy Bantu speakers since agropastoral lifestyle spread across sub-Saharan Africa. Ethnographic studies have reported that their diets differ in consumption of both animal proteins and starch grains. Hunted meat and gathered plant foods, especially underground storage organs (USOs), are dietary staples for pygmies. However, scarce information exists about forager-farmer interaction and the agricultural products used by pygmies. Since the effects of dietary preferences on teeth in modern and past pygmies remain unknown, we explored dietary history through quantitative analysis of buccal microwear on cheek teeth in well-documented Baka pygmies. We then determined if microwear patterns differ among other Pygmy groups (Aka, Mbuti, and Babongo) and between Bantu-speaking farmer and pastoralist populations from past centuries. The buccal dental microwear patterns of Pygmy hunter-gatherers and non-Pygmy Bantu pastoralists show lower scratch densities, indicative of diets more intensively based on nonabrasive foodstuffs, compared with Bantu farmers, who consume larger amounts of grit from stoneground foods. The Baka pygmies showed microwear patterns similar to those of ancient Aka and Mbuti, suggesting that the mechanical properties of their preferred diets have not significantly changed through time. In contrast, Babongo pygmies showed scratch densities and lengths similar to those of the farmers, consistent with sociocultural contacts and genetic factors. Our findings support that buccal microwear patterns predict dietary habits independent of ecological conditions and reflect the abrasive properties of preferred or fallback foods such as USOs, which may have contributed to the dietary specializations of ancient human populations.

  17. Diet-related buccal dental microwear patterns in Central African Pygmy foragers and Bantu-speaking farmer and pastoralist populations.

    Directory of Open Access Journals (Sweden)

    Alejandro Romero

    Full Text Available Pygmy hunter-gatherers from Central Africa have shared a network of socioeconomic interactions with non-Pygmy Bantu speakers since agropastoral lifestyle spread across sub-Saharan Africa. Ethnographic studies have reported that their diets differ in consumption of both animal proteins and starch grains. Hunted meat and gathered plant foods, especially underground storage organs (USOs, are dietary staples for pygmies. However, scarce information exists about forager-farmer interaction and the agricultural products used by pygmies. Since the effects of dietary preferences on teeth in modern and past pygmies remain unknown, we explored dietary history through quantitative analysis of buccal microwear on cheek teeth in well-documented Baka pygmies. We then determined if microwear patterns differ among other Pygmy groups (Aka, Mbuti, and Babongo and between Bantu-speaking farmer and pastoralist populations from past centuries. The buccal dental microwear patterns of Pygmy hunter-gatherers and non-Pygmy Bantu pastoralists show lower scratch densities, indicative of diets more intensively based on nonabrasive foodstuffs, compared with Bantu farmers, who consume larger amounts of grit from stoneground foods. The Baka pygmies showed microwear patterns similar to those of ancient Aka and Mbuti, suggesting that the mechanical properties of their preferred diets have not significantly changed through time. In contrast, Babongo pygmies showed scratch densities and lengths similar to those of the farmers, consistent with sociocultural contacts and genetic factors. Our findings support that buccal microwear patterns predict dietary habits independent of ecological conditions and reflect the abrasive properties of preferred or fallback foods such as USOs, which may have contributed to the dietary specializations of ancient human populations.

  18. Evaluation of prescribing indicators and pattern among dermatological outpatients in a teaching hospital of central Nepal

    Directory of Open Access Journals (Sweden)

    Manohar Pradhan

    2016-08-01

    Full Text Available Background: Evaluation of prescribing indicators by proper analysis of prescriptions under the guidelines of World Health Organization enables us to detect some of the common problems of prescribing.Methodology: This study was conducted on randomly selected 325 prescriptions of dermatological outpatients of teaching hospital of College of Medical Sciences Bharatpur (Nepal with an objective to detect the problems of prescribing as well as to delineate the pattern of medicines prescribing.Results: Total number of medicines prescribed on these prescriptions was 743. The average number of medicines per encounter was 2.28. Antihistamines, antifungals, corticosteroids and antibiotics were four most frequently prescribed therapeutic classes. One systemic as well as one topical medicine belonging to same therapeutic class was prescribed on about one-third of totally analyzed prescriptions. Cetrizine was the most common individually prescribed medicine and fluconazole was the most commonly prescribed antifungal. Medicines prescribed by their generic name were 15.07% and those prescribed from national essential medicines list were 23.42%.Conclusion: This study reveals polypharmacy, inclination of prescribers for branded medicines and prescribing out of national formulary as problems. Educational and managerial interventions are required to rationalize the prescribing practice.JCMS Nepal. 2016;12(2:44-9.

  19. Centralized optical-frequency-comb-based RF carrier generator for DWDM fiber-wireless access systems

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltran, Marta; Sanchez, Jose;

    2014-01-01

    In this paper, we report on a gigabit capacity fiber-wireless system that enables smooth integration between high-speed wireless networks and dense wavelength-division-multiplexing (DWDM) access networks. By employing a centralized optical frequency comb, both the wireline and the wireless services...

  20. Pattern of self-medication with analgesics among Iranian University students in central Iran

    Directory of Open Access Journals (Sweden)

    Shadi Sarahroodi

    2012-01-01

    Full Text Available Background: Self-medication is defined as the use of drugs for the treatment of self-diagnosed disorders. It is influenced by factors such as education, family, society, law, availability of drugs and exposure to advertisements. This study was performed to evaluate self-medication with analgesics and its pattern among different groups of Iranian University Students. Materials and Methods: A randomized, cross-sectional, multicenter study was conducted from December 2009 to February 2010. The target population of this study was 564 students out of 10,000 students attending four medical and non-medical science universities in Qom state. Data was analyzed using SPSS version 16, and analysis was conducted with descriptive analysis procedures. Results: 76.6% of the students had used analgesics in self-medication in the previous 3 months. The frequency of analgesic use in the study period was once in 19.2% of the participants, twice in 22.2%, three times in 16.3% and more than three times in 35.5% of the participants, although 6.8% of them were not sure when they were used. Of all the respondents, 49.8% reported headache as the problem. This was the most common problem, after which came Dysmenorrhea,headache and stomach ache. Bone and joint pains were other problems that led to the use of analgesics. The most commonly used source of information for self-medication with analgesics was advice from friends and family (54.7%, previously prescribed medications (30.1%, their medical knowledge (13.3% and recommendation of a pharmacist (1.9%. Conclusion: Self-medication with analgesics is very high among Iranian students in Qom city. This could be an index for other parts of the Iranian community. Because the source of information about analgesics is inappropriate, we would recommend education courses about analgesics and self-medication on the radio and television for the entire population.

  1. Annual Patterns and Sources of Light-Absorbing Aerosols over Central Greenland

    Science.gov (United States)

    Hu, J.; Bergin, M. H.; Dibb, J. E.; Sheridan, P. J.; Ogren, J. A.

    2014-12-01

    The Arctic region has proven to be more responsive to recent changes in climate than other parts of the Earth. A key component of the Arctic climate is the Greenland ice sheet (GIS), which has the potential to dramatically influence sea level, depending on the amount of melting that occurs, as well as climate, through shifts in the regional radiation balance. Light-absorbing aerosols from biomass burning, fossil fuel combustion, and dust sources can potentially have a significant impact on the radiation balance of the GIS; however, in order to better understand their impact, it is important to first understand the annual trends of light-absorbing aerosols and their sources over the ice sheet. With this in mind, aerosol properties including the wavelength dependent aerosol light scattering and absorption coefficients have been continuously measured at Summit, Greenland since the spring of 2011. These measurements will be used to calculate the multi-wavelength single-scattering albedo (ω0) and absorption Ångström exponent, identify annual patterns of aerosols over the GIS and how they vary from year to year, detect events of high absorption, and determine the sources of the aerosols. Preliminary findings indicate that the aerosols have an absorption Ångström exponent of approximately 1, which is characteristic of black carbon (BC). Absorption and scattering coefficients are higher in the spring and summer (March-September) and consequently lower in the fall and winter (September-March). Absorption and single-scattering albedo are averaged over the sunlit months of April-August and are found to be highest and lowest, respectively, in the year of 2012, corresponding to the year of record melt extent over the GIS.

  2. The tree water isoscape of a central Pennsylvania catchment: ecohydrologic patterns and processes

    Science.gov (United States)

    Brubaker, K. M.; Gaines, K.

    2015-12-01

    The connections between vegetation and catchment hydrology are important for tree physiology, plant geography, stream flow, and transport of solutes within a watershed. While water isotopes from tree stems have been studied extensively to examine source-water differences at a small scale, there has been little emphasis on modeling of plant stem water isotopes at larger scales, due to the expensive and laborious extraction and analysis processes. We characterized the tree stem water for stable isotopes over a landscape (isoscape) at a first-order catchment in central Pennsylvania in order to address the following questions: 1) How does tree water isotopic composition relate to catchment topography and tree characteristics? 2) What are the underlying hydrologic processes that are revealed by tree water isotopes? We used 267 observations of tree xylem water δ18O from 121 trees to build a statistical model with candidate variables related to topography and tree characteristics. We then applied the final model to predict the tree xylem water δ18O composition during the growing season of the remaining trees defined as > 18-cm diameter (at breast height; DBH) in the catchment. The final model included tree canopy height and slope magnitude as predictors, and explained about 56% of variance in tree water δ18O composition in the catchment. Tree canopy height and degree of slope were both negatively related to tree water δ18O suggesting the tallest trees and trees on the steepest slopes had tree water isotopic compositions most depleted in heavy isotopes. Each of these suggested the influence of cool-season isotopic inputs. On the valley floor, where tree canopy heights were tallest, the tree water δ18O composition was likely due to early growing season soil saturation from a shallow ground water table. Conversely, the steep hill slope δ18O composition may be a result of tree water use of tightly-bound soil water originating from cool season precipitation. The model

  3. Dopaminergic Receptors and Tyrosine Hydroxylase Expression in Peripheral Blood Mononuclear Cells: A Distinct Pattern in Central Obesity

    Science.gov (United States)

    Leite, Fernanda; Lima, Margarida; Marino, Franca; Cosentino, Marco; Ribeiro, Laura

    2016-01-01

    Background Dopamine (DA) may be involved in central obesity (CO), an inflammatory condition, through its role in the central nervous system and in periphery, where it may affect immune cell function through five different DA receptors (DR). Whether dopaminergic pathways in peripheral immune cells are implicated in the inflammatory condition linked to CO is however unknown. Methods In a cohort of blood donors with and without CO, categorized by waist circumference (WC) (CO: WC ≥0.80 m in women and ≥0.94 m in men), we studied the expression of DR and tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of DA, in peripheral blood mononuclear cells (PBMCs) and their relation with anthropometric and metabolic/endocrine and inflammatory parameters. DR D1-5 and TH expression was assessed by semi quantitative real-time PCR. As inflammatory markers we investigated the immunophenotype of monocyte subsets by flow cytometry, staining for CD14, CD16, CD11b and CD36. Results CO individuals showed higher plasma levels of leptin and higher inflammatory pattern of monocytes compared with non-CO. PBMC expression of DR D2, DR D4 and DR D5 as well as of TH were lower in CO in comparison with non-CO. DR D2, and DR D5 expression correlated with lower WC and weight, and with lower inflammatory pattern of monocytes, and TH expression correlated with lower WC. DR D4 expression correlated with lower plasma levels of glycosylated hemoglobin, and DR D2 expression correlated with lower CO. Conclusions Results show that CO is associated with peripheral inflammation and downregulation of dopaminergic pathways in PBMCs, possibly suggesting DR expressed on immune cells as pharmacological targets in obesity for better metabolic outcome. PMID:26808524

  4. Lack of differential pattern in central adiposity and metabolic syndrome in Barrett's esophagus and gastroesophageal reflux disease.

    LENUS (Irish Health Repository)

    Healy, L A

    2012-02-01

    Obesity is an established risk factor for esophageal adenocarcinoma, although the mechanism is unclear. A pathway from reflux to inflammation through metaplasia is the dominant hypothesis, and an added role relating to visceral adiposity and the metabolic syndrome has been mooted in Barrett\\'s esophagus (BE) patients. Whether BE differs from gastroesophageal reflux disease (GERD) in obesity and metabolic syndrome profiles is unclear, and this was the focus of this study. Patients with proven BE or GERD were randomly selected from the unit data registry and invited to attend for metabolic syndrome screening, anthropometry studies including segmental body composition analysis, and laboratory tests including fasting lipids, insulin, and C-reactive protein. Metabolic syndrome was defined using the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF) criteria. One hundred and eighteen BE patients and 113 age- and sex-matched GERD controls were studied. The incidence of obesity (body mass index >30 kg\\/m(2)) was 36% and 38%, respectively, with the pattern of fat deposition predominantly central and an estimated trunk fat mass of 13 and 14 kg, respectively. Using the NCEP criteria, metabolic syndrome was significantly more common in the BE cohort (30% vs 20%, P < 0.05), but there was no significant difference using IDF criteria (42% vs 37%, P= 0.340). Central obesity and the metabolic syndrome are common in both Barrett\\'s and GERD cohorts, but not significantly different, suggesting that central obesity and the metabolic syndrome does not per se impact on the development of BE in a reflux population. In BE, the importance of obesity and the metabolic syndrome in disease progression merits further study.

  5. Concept and analytical basis for revistas - A fast, flexible computer/graphic system for generating periodic satellite coverage patterns

    Science.gov (United States)

    King, J. C.

    1976-01-01

    The generation of satellite coverage patterns is facilitated by three basic strategies: use of a simplified physical model, permitting rapid closed-form calculation; separation of earth rotation and nodal precession from initial geometric analyses; and use of symmetries to construct traces of indefinite length by repetitive transposition of basic one-quadrant elements. The complete coverage patterns generated consist of a basic nadir trace plus a number of associated off-nadir traces, one for each sensor swath edge to be delineated. Each trace is generated by transposing one or two of the basic quadrant elements into a circle on a nonrotating earth model sphere, after which the circle is expanded into the actual 'helical' pattern by adding rotational displacements to the longitude coordinates. The procedure adapts to the important periodic coverage cases by direct insertion of the characteristic integers N and R (days and orbital revolutions, respectively, per coverage period).

  6. Risk and cost comparison of energy technologies for central electric power generation

    International Nuclear Information System (INIS)

    An evaluation of nuclear energy as it relates to alternative sources of electric power generation is presented. Citing Duke Power Company's Oconee Nuclear Station, the nuclear option in the past was the obvious choice. Today it is still the preferred alternative both economically and because of increasing environmental concerns over other energy alternatives. Public acceptance of nuclear generation, following Three Mile Island, remains a significant hurdle in its path

  7. Initial benchmarking of a new electron-beam raster pattern generator for 130-100 nm maskmaking

    Science.gov (United States)

    Sauer, Charles A.; Abboud, Frank E.; Babin, Sergey V.; Chakarian, Varoujan; Ghanbari, Abe; Innes, Robert; Trost, David; Raymond, Frederick, III

    2000-07-01

    The decision by the Semiconductor Industry Association (SIA) to accelerate the continuing evolution to smaller linewidths is consistent with the commitment by Etec Systems, Inc. to rapidly develop new technologies for pattern generation systems with improved resolution, critical dimension (CD) uniformity, positional accuracy, and throughput. Current pattern generation designs are inadequate to meet the more advanced requirements for masks, particularly at or below the 100 nm node. Major changes to all pattern generation tools will be essential to meet future market requirements. An electron-beam (e-beam) system that is designed to meet the challenges for 130 - 100 nm device generation with extendibility to the 70-nm range will be discussed. This system has an architecture that includes a graybeam writing strategy, a new state system, and improved thermal management. Detailed changes include a pulse width modulated blanking system, per-pixel deflection, retrograde scanning multipass writing, and a column with a 50 kV accelerating voltage that supports a dose of up to 45 (mu) C/cm2 with minimal amounts of resist heating. This paper examines current issues, our approach to meeting International Technology Roadmap for Semiconductors (ITRS) requirements, and some preliminary results from a new pattern generator.

  8. Two interconnected kernels of reciprocally inhibitory interneurons underlie alternating left-right swim motor pattern generation in the mollusk Melibe leonina.

    Science.gov (United States)

    Sakurai, Akira; Gunaratne, Charuni A; Katz, Paul S

    2014-09-15

    The central pattern generator (CPG) underlying the rhythmic swimming behavior of the nudibranch Melibe leonina (Mollusca, Gastropoda, Heterobranchia) has been described as a simple half-center oscillator consisting of two reciprocally inhibitory pairs of interneurons called swim interneuron 1 (Si1) and swim interneuron 2 (Si2). In this study, we identified two additional pairs of interneurons that are part of the swim CPG: swim interneuron 3 (Si3) and swim interneuron 4 (Si4). The somata of Si3 and Si4 were both located in the pedal ganglion, near that of Si2, and both had axons that projected through the pedal commissure to the contralateral pedal ganglion. These neurons fulfilled the criteria for inclusion as members of the swim CPG: 1) they fired at a fixed phase in relation to Si1 and Si2, 2) brief changes in their activity reset the motor pattern, 3) prolonged changes in their activity altered the periodicity of the motor pattern, 4) they had monosynaptic connections with each other and with Si1 and Si2, and 5) their synaptic actions helped explain the phasing of the motor pattern. The results of this study show that the motor pattern has more complex internal dynamics than a simple left/right alternation of firing; the CPG circuit appears to be composed of two kernels of reciprocally inhibitory neurons, one consisting of Si1, Si2, and the contralateral Si4 and the other consisting of Si3. These two kernels interact with each other to produce a stable rhythmic motor pattern.

  9. Characteristics of U-pattern distribution of high-concentration 210Pb in surface air at central Guizhou, China

    Institute of Scientific and Technical Information of China (English)

    WAN Guojiang; YANG Wei; WANG Shilu; WAN Enyuan; WU Fengchang; S.N.LEE; WANG Changsheng; HUANG Ronggui

    2005-01-01

    A better understanding of the variation of 210Pb concentrations in the surface air is the key to trace lake sedimentation and catchment erosion, to establish and validate the global diffusion model of contaminants, and to assess the impact of natural radiation on the ecological system. Basing on the study progresses of the sedimentation, the atmospheric model and the unique environmental background in the Yunnan-Guizhou Plateau, and starting from December 20, 2001, we made use of a 500 NE Type aerosol sampler to collect filter samples, once a week in the past consecutive two years, in the surface air at Mt. Guanfeng, Guiyang City, China. Synchronous detailed γ-energy spectrometric observations of 210Pb concentrations at both Chinese and U.S. laboratories have shown that the average monthly 210Pb concentration displays a regular U-patterns distribution of annual variations, with high values appearing in winter and low values in late spring and summer. The average annual 210Pb concentrations are estimated to be 2.77±0.63 mBq/m3, about 4 times the average maximum concentrations reported from quite a number of monitoring stations throughout the world. The possible factors affecting the sources of 210Pb in the surface air in the central part of Guizhou Province are: Release of 222Rn from the U-Ra series enriched in the soils; chemical weathering of carbonate rocks; the exploitation, processing and utilization of coal and phosphorous resources. The principal factor controlling the high 210Pb concentrations in the surface air in the central Guizhou and their annual U-pattern distribution is the release of 222Rn. The average monthly 210Pb concentrations show a good negative power- function relationship with increasing precipitation and also show a good negative linear-function relationship with the rise of air temperature in month grouping. Group No.1 (June to November) reflects a relatively low release of 222Rn from soils in relatively high temperature seasons; Group No

  10. CENCAL_BASELINE - Offshore Baseline for Central California Generated to Calculate Shoreline Change Rates

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Rates of long-term and short-term shoreline change were generated in a GIS using the Digital Shoreline Analysis System (DSAS) version 3.0; An ArcGIS extension for...

  11. Evaluating the temporal stability of synthetically generated time-series for crop types in central Germany

    Science.gov (United States)

    Synthetically generated Landsat time-series based on the STARFM algorithm are increasingly used for applications in forestry or agriculture. Although successes in classification and derivation of phenological orbiomass parameters are evident, a thorough evaluation of the limits of the method is stil...

  12. Sustainability Assessment of a Self-Consumption Wood-Energy Chain on Small Scale for Heat Generation in Central Italy

    OpenAIRE

    Stefano Verani; Giulio Sperandio; Rodolfo Picchio; Enrico Marchi; Corrado Costa

    2015-01-01

    The sustainability of a small-scale self-consumption wood-energy chain for heat generation in central Italy was analyzed from a technical, economic and energetic point of view. A micro-chain was developed within the CRA-ING farm at Monterotondo (Rome, Italy): The purpose of this system was to produce biomass for supplying a heating plant within the CRA-ING property as a substitute for diesel fuel. A poplar short rotation coppice, established with clones AF2, AF6 and Monviso, fed the micro-cha...

  13. Designing responsive pattern generators: stable heteroclinic channel cycles for modeling and control.

    Science.gov (United States)

    Horchler, Andrew D; Daltorio, Kathryn A; Chiel, Hillel J; Quinn, Roger D

    2015-04-01

    A striking feature of biological pattern generators is their ability to respond immediately to multisensory perturbations by modulating the dwell time at a particular phase of oscillation, which can vary force output, range of motion, or other characteristics of a physical system. Stable heteroclinic channels (SHCs) are a dynamical architecture that can provide such responsiveness to artificial devices such as robots. SHCs are composed of sequences of saddle equilibrium points, which yields exquisite sensitivity. The strength of the vector fields in the neighborhood of these equilibria determines the responsiveness to perturbations and how long trajectories dwell in the vicinity of a saddle. For SHC cycles, the addition of stochastic noise results in oscillation with a regular mean period. In this paper, we parameterize noise-driven Lotka-Volterra SHC cycles such that each saddle can be independently designed to have a desired mean sub-period. The first step in the design process is an analytic approximation, which results in mean sub-periods that are within 2% of the specified sub-period for a typical parameter set. Further, after measuring the resultant sub-periods over sufficient numbers of cycles, the magnitude of the noise can be adjusted to control the mean period with accuracy close to that of the integration step size. With these relationships, SHCs can be more easily employed in engineering and modeling applications. For applications that require smooth state transitions, this parameterization permits each state's distribution of periods to be independently specified. Moreover, for modeling context-dependent behaviors, continuously varying inputs in each state dimension can rapidly precipitate transitions to alter frequency and phase. PMID:25712192

  14. Primary seed shadow generated by gibbons in the rain forests of Barito Ulu, central Borneo.

    Science.gov (United States)

    McConkey, K R

    2000-09-01

    Gibbons are one of the main frugivores in the forests of Southeast Asia, and consequently have long been considered to be good seed dispersers. This is the first study in which the primary seed shadow they create by their ranging and foraging activities is evaluated in detail. I studied two gibbon groups over 12 months in lowland dipterocarp forest in central Borneo. The gibbons dispersed up to 81% of the species they consumed and destroyed the seeds of only 12%. Fruit with elongated seeds (up to 20 mm wide) were more likely to be dispersed than round seeds. Considering that the survival rate of seeds in the forest to one year was 8%, the gibbons effectively dispersed 13 seedlings ha(-1) group(-1) year(-1). Their effect on germination was very variable, although most species did eventually germinate. Most seeds were deposited along their major ranging routes and close to or under feeding trees. PMID:10993135

  15. Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus.

    Science.gov (United States)

    Cerón-Souza, Ivania; Gonzalez, Elena G; Schwarzbach, Andrea E; Salas-Leiva, Dayana E; Rivera-Ocasio, Elsie; Toro-Perea, Nelson; Bermingham, Eldredge; McMillan, W Owen

    2015-08-01

    Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life-history traits on diversification of unrelated but co-distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present-day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life-history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid-Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life-history traits of mangrove species, which should have had a strong influence on seed

  16. Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus.

    Science.gov (United States)

    Cerón-Souza, Ivania; Gonzalez, Elena G; Schwarzbach, Andrea E; Salas-Leiva, Dayana E; Rivera-Ocasio, Elsie; Toro-Perea, Nelson; Bermingham, Eldredge; McMillan, W Owen

    2015-08-01

    Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life-history traits on diversification of unrelated but co-distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present-day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life-history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid-Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life-history traits of mangrove species, which should have had a strong influence on seed

  17. Trading Signal Generation Using A Combination of Chart Patterns and Indicators

    OpenAIRE

    Chalothon Chootong; Ohm Sornil,

    2012-01-01

    Chart patterns and indicators are popular technical tools for making investment decisions. This article presents a trading strategy combining price movement patterns, candlestick chart patterns, and trading indicators, including Moving Average, Exponential Moving Average, Bollinger Bands, On Balance Volume, Relative Strength Index, Moving Average Convergence Divergence, and Stochastic Oscillator, with the aim to increase the return on investment. A neural network ensemble is employed to deter...

  18. Development of the control assembly pattern and dynamic analysis of the Generation IV large gas-cooled fast reactor (GFR)

    International Nuclear Information System (INIS)

    During the past ten years, different independent factors, such as the rapidly increasing worldwide demand in energy, societal concerns about greenhouse gas emissions, and the high and volatile prices for fossil fuels, have contributed to the renewed interest in nuclear technology. In this context, the Generation IV International Forum (GIF) launched the initiative to collaborate on the research and development efforts needed for the next generation of nuclear reactors. A particular goal set for Generation IV systems is closure of the nuclear fuel cycle; they are expected to offer a better utilization of natural resources, as also a minimization of long-lived radioactive wastes. Among the systems selected by the GIF, the Gas-cooled Fast Reactor (GFR) is a highly innovative system with advanced fuel geometry and materials. The principal aim of the present research is to develop and qualify the control assembly (CA) pattern and corresponding CA implementation scheme for the 2400 MWth reference GFR design. The work has been carried out in three successive phases: (1) validation of the neutronics tools, (2) the CA pattern development and related static analysis, and (3) dynamic core behaviour studies for hypothetical CA driven transients. The deterministic code system ERANOS and its associated nuclear data libraries for fast reactors were developed and validated for sodium-cooled reactors. In order to validate ERANOS for GFR applications, a systematic reanalysis of the GFR-relevant integral data generated at PSI during the GCFR-PROTEUS experimental program of the 1970’s was undertaken. The reference PROTEUS test lattice has been analyzed with ERANOS-2.0 and its associated, adjusted nuclear data library ERALIB1. Benchmark calculations were performed with the Monte Carlo code MCNPX, allowing one to both check the deterministic results and to analyze the sensitivity to different modern data libraries. For the main reaction rate ratios, the new analysis of the GCFR

  19. Choice between hierarchy and market: Case of Central Electricity Generating Board's reorganization

    International Nuclear Information System (INIS)

    Through the use of the 'Organization and Market' theoretical approach, this article outlines CEGB's reorganization to evaluate this experience under the strategic planning and operating effectiveness perspectives. The first part synthesizes the basic points of the 1990 reform which divided CEGB into three different companies and separated the control of the generation of electric power from its transport. The second part summarizes the main considerations about conditions of efficiency of vertical integration and disintegration, according to the 'Organization and Market' approach. By utilizing the conclusions highlighted in the first two parts of this article, the third one studies the effects of CEGB's vertical disintegration on the level of competition in power generation market; on CEGB's strategic effectiveness and operative efficiency; and on transactional costs in the electric power industry. CEGB's reorganization does not seem to have had a relevantly positive effect on competition, while it has caused a strategic burden and a significant increase of transactional costs in the exchange of electricity between the generator and the transmitter

  20. Control and Modulation Techniques for a Centralized PV Generation System Grid Connected via an Interleaved Inverter

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-09-01

    Full Text Available In the context of grid connected photovoitaic (PV generation systems, there are two paramount aspects regarding the Maximum Power Point Tracking (MPPT of the photovoltaic units and the continuity of the service. The most diffused MPPT algorithms are based on either perturb and observe, or on an incremental conductance approach and need both PV current and voltage measurements. Several topology reconfigurable converters are also associated with the PV plants, guaranteeing fault-tolerant features. The generation continuity can also be assured by interleaved inverters, which keep the system operating at reduced maximum power in case of failure. In this paper, an evolution of a hysteresis based MPPT algorithm is presented, based on the measurement of only one voltage, together with a novel space vector modulation suitable for a two-channel three-phase grid connected interleaved inverter. The proposed MMPT algorithm and modulation technique are tested by means of several numerical analyses on a PV generation system of about 200 kW maximum power. The results testify the validity of the proposed strategies, showing good performance, even during a fault occurrence and in the presence of deep shading conditions.

  1. Patterns of fossil distributions within their environmental context from the Middle Triassic in South Canyon,Central Nevada,USA

    Institute of Scientific and Technical Information of China (English)

    Pedro; M.Monarrez; Nicole; Bonuso

    2014-01-01

    The Middle Triassic records the return of diverse marine communities after the severe effects of the end-Permian mass extinction.This diversification leads to the Mesozoic/modern adaptive radiation resulting in substantial changes in marine communities in comparison to their Paleozoic predecessors.This analysis focuses on the faunal abundance,ecological patterns,and environmental interpretation of a Middle Triassic section in Central Nevada.Twelve bulk samples were collected.Visible fossils were identified and tallied from hand samples and thin-sections were used to aid in environmental interpretation.Beginning in the Late Anisian,we observed an ammonoid dominated to flat-clam,epifaunal dominated benthic community within a muddy,quiet,inner shelf depositional environment.Through time,epifaunal bivalves dominate within a middle shelf environment followed by an increase in infaunalization and shell-thickness.During this time the presence of oncoids and the reported finding of corals suggest the middle shelf environment gave way to a higher energy patch reef shelf edge environment.Finally,we observe epifaunal brachiopods communities at the top of our section deposited in a middle shelf environment.In sum,we observe the dominance of modern taxa(i.e.,bivalves)with Paleozoic ecologies(i.e.,epifaunal),followed by the dominance of modern taxa with Modern ecologies(i.e.,infaunal,thick shells)and then a return to Paleozoic taxa(i.e.,brachiopods)and Paleozoic ecologies within an overall transgressive environment.

  2. Patterns of mouse reticulon 3 mRNA and protein expression in the mouse central nervous system

    Institute of Scientific and Technical Information of China (English)

    LIU Jin; QIANG Boqin; YUAN Jiangang; HUANG Xiaowei; PENG Xiaozhong; YANG Hongbo; YIN Bin; TAN Xinyu; FAN Ming; FAN Wenhong; LIU Bingyan

    2003-01-01

    Reticulons (RTN) are endoplasmic reticulumassociated protein complexes, which are localized in the endoplasmic reticulum (ER) and identified as markers for neuroendocrine differentiation. At least four different RTN genes have been identified in mammals, but in most cases,the functions of the encoded proteins except mammalian RTN4-A and RTN4-B are still elusive. In the present study,mouse reticulon 3 (mRTN3) is cloned and its expression pattern in a variety of tissues is investigated. Three alternatively spliced transcripts of 1.8, 2.8 and 4.2 kb are revealed by Northern blotting hybridization. The 1.8 and 2.8 kb transcripts are expressed in many tissues. The 2.8 kb transcript has a high level in brain and the 4.2 kb transcript is only found in brain. In situ hybridization and immunohistochemical analysis indicated its high expression in non-glial cells in some particular region of mouse central nervous system, such as hippocampus, sub-thalamus nucleus, thalamus nucleus and cerebrum cortex.

  3. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

    2006-07-01

    The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the

  4. Convective thermal fluxes in unsteady non-homogeneous flows generating complex three dimensional vorticity patterns

    Science.gov (United States)

    Tellez Alvarez, Jackson David; Redondo, Jose Manuel; Sanchez, Jesu Mary

    2016-04-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form convective driven mixing. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2, 3]. We parametrize the role of unstable stratification by means of the Rayleigh and Atwood numbers and compare the scaling and the multifractal structure functions of the different markers used to visualize the non-homogeneous. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overall turbulent process is evaluated [4 - 6]. Diffusion is measured in the transition from a homogeneous linearly stratified fluid to a cellular or layered structure by means of Thermoelectric generated heating and cooling [2, 4]. Patterns arise by setting up a convective flow generated by a buoyant heat flux either in the base or in a side wall of the convective enclosure [1, 6]. The experiments described here investigate high Prandtl number mixing using brine or sugar solutions and fresh water in order to form a density interface and low Prandtl number mixing with only temperature gradients [7]. The set of dimensionless parameters define conditions of numeric and small scale laboratory modeling of environmental flows. Fields of velocity, density and their gradients were computed and visualized [8, 9]. When convective heating and cooling takes place the combination of internal waves and buoyant turbulence is much more complicated if the Rayleigh and Reynolds numbers are high in order to study entrainment and mixing. The experiments described here investigate high Prandtl number mixing using salt or sugar solutions and

  5. Extreme ultraviolet lithography patterned mask defect detection performance evaluation toward 16- to 11-nm half-pitch generation

    Science.gov (United States)

    Hirano, Ryoichi; Iida, Susumu; Amano, Tsuyoshi; Watanabe, Hidehiro; Hatakeyama, Masahiro; Murakami, Takeshi; Yoshikawa, Shoji; Terao, Kenji

    2015-07-01

    High-sensitivity and low-noise extreme ultraviolet (EUV) mask pattern defect detection is one of the major issues remaining to be addressed in device fabrication using extreme ultraviolet lithography (EUVL). We have designed a projection electron microscopy (PEM) system, which has proven to be quite promising for half-pitch (hp) 16-nm node to hp 11-nm node mask inspection. The PEM system was integrated into a pattern inspection system for defect detection sensitivity evaluation. To improve the performance of hp 16-nm patterned mask defect detection toward hp 11-nm EUVL patterned mask, defect detection signal characteristics, which depend on hp 64-nm pattern image intensity deviation on EUVL mask, were studied. Image adjustment effect of the captured images for die-to-die defect detection was evaluated before the start of the defect detection image-processing sequence. Image correction of intrafield intensity unevenness and L/S pattern image contrast deviation suppresses the generation of false defects. Captured images of extrusion and intrusion defects in hp 64-nm L/S patterns were used for detection. Applying the image correction for defect detection, 12-nm sized intrusion defect, which was smaller than our target size for hp 16-nm defect detection requirements, was identified without false defects.

  6. Implementing a Generative Urban Design Model: Grammar-based design patterns for urban design

    NARCIS (Netherlands)

    Beirao, J.N.; Mendes, G.; Duarte, J.; Stouffs, R.M.F.

    2010-01-01

    This paper shows the first results of a prototype implementation of a generative urban design tool. This implementation will form part of a design support tool for a GIS based platform defined to formulate, generate and evaluate urban designs. These three goals, formulation, generation and evaluatio

  7. A New Generation of Large Seismic Refraction Experiments in Central Europe (1997-2003)

    Science.gov (United States)

    Guterch, A.; Grad, M.; Spicak, A.; Brueckl, E.; Hegedus, E.; Keller, G. R.; Thybo, H.

    2003-12-01

    Beginning in 1997, Central Europe has been covered by an unprecedented network of seismic refraction experiments. These experiments (POLONAISE'97, CELEBRATION 2000, ALP 2002, SUDETES 2003) have only been possible due a massive international cooperative effort. The total length of all profiles is about 19,000 km, and over 300 explosive sources were employed. The result is a network of seismic refraction profiles that extends along the Trans-European Suture Zone region of Poland and the Bohemian massif, Pannonian basin, trough the Carpathians and Alps to the Adriatic Sea and the Dinarides. As reflected in structures within these areas, Central Europe has experienced a complex tectonic history that includes the Caledonian, Variscan, and Alpine orogenies. The related TESZ region is a broad zone of deformation that extends across Europe from British Isles to the Black Sea region that formed as Europe was assembled from a complex collage of terranes during the late Palaeozoic. For example, the Bohemian massif is mostly located in the Czech Republic and is a large, complex terrane whose origin can be traced to northern Gondwana (Africa). These terranes were accreted along the margin of Baltica that was formed during the break-up of Rodinia. The tectonic evolution of this region shares many attributes with the Appalachian/Ouachita origin and is certainly of global important to studies in terrane tectonics and continental evolution. In southern Poland, several structural blocks are located adjacent to Baltica and were probably transported laterally along it similar to the Cenozoic movement of terranes along the western margin of North America. The younger Carpathian arc and Pannonian back-arc basin were also targeted by these experiments. Thickness of the crust in the area of investigations changes from 22-25 km in the Pannonian basin to about 55 km in the Trans-European Suture Zone in SE Poland. Together, these experiments are providing an unprecedented 3-D image of the

  8. Trading Signal Generation Using A Combination of Chart Patterns and Indicators

    Directory of Open Access Journals (Sweden)

    Chalothon Chootong

    2012-11-01

    Full Text Available Chart patterns and indicators are popular technical tools for making investment decisions. This article presents a trading strategy combining price movement patterns, candlestick chart patterns, and trading indicators, including Moving Average, Exponential Moving Average, Bollinger Bands, On Balance Volume, Relative Strength Index, Moving Average Convergence Divergence, and Stochastic Oscillator, with the aim to increase the return on investment. A neural network ensemble is employed to determine buy and sell signals on the next trading day. Experimental results, using stocks from five different industries in Stock Exchange of Thailand, show that the proposed strategy yields higher returns than do traditional technical trading methods

  9. Characterization methods of nano-patterned surfaces generated by induction heating assisted injection molding

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Ravn, Christian; Menotti, Stefano;

    2015-01-01

    An induction heating-assisted injection molding (IHAIM) process developed by the authors is used to replicate surfaces containing random nano-patterns. The injection molding setup is developed so that an induction heating system rapidly heats the cavity wall at rates of up to 10◦C/s. In order...... to enable the optimization of the IHAIM process for nano-pattern replication, it is necessary to develop robust methods for quantitative characterization of the replicated nano-patterns. For this purpose, three different approaches for quantitative characterization of random nano-patterns are applied...... and compared. Results show that the use of IHAIM is an efficient way to improve replication quality. All three measurement methods are capable of detecting the trend of the replication quality of the surface changing the process condition....

  10. Assessment of the once-through cooling alternative for central steam-electric generating stations

    Energy Technology Data Exchange (ETDEWEB)

    Paddock, R. A.; Ditmars, J. D.

    1978-12-01

    The efficacy of the disposal of waste heat from steam-electric power generation by means of once-through cooling systems was examined in the context of the physical aspects of water quality standards and guidelines for thermal discharges. Typical thermal standards for each of the four classes of water bodies (rivers, lakes, estuaries, and coastal waters) were identified. The mixing and dilution characteristics of various discharge modes ranging from simple, shoreline surface discharges to long, submerged multiport diffusers were examined in terms of the results of prototype measurements, analytical model predictions, and physical model studies. General guidelines were produced that indicate, for a given plant capacity, a given type of receiving water body, and a given discharge mode, the likelihood that once-through cooling can be effected within the restrictions of typical thermal standards. In general, it was found that shoreline surface discharges would not be adequate for large power plants (greater than or equal to 500 MW) at estuarine and marine coastal sites, would be marginally adequate at lake sites, and would be acceptable only at river sites with large currents and river discharges. Submerged multiport diffusers were found to provide the greatest likelihood of meeting thermal standards in all receiving water environments.

  11. Rough set based decision rule generation to find behavioural patterns of customers

    Indian Academy of Sciences (India)

    L SUMALATHA; P UMA SANKAR; B SUJATHA

    2016-09-01

    Rough sets help in finding significant attributes of large data sets and generating decision rules for classifying new instances. Though multiple regression analysis, discriminant analysis, log-it analysis and several other techniques can be used for predicting results, they consider insignificant information also for processing which may lead to false positives and false negatives. In this study, we proposed rough set based decision rule generation framework to find reduct and to generate decision rules for predicting the Decision class. We conducted experiments over data of Portuguese Banking institution. From the proposed method, the dimensionality of data is reduced and decision rules are generated which predicts deposit nature of customers by 90%accuracy.

  12. Single-neuron diversity generated by Protocadherin-β cluster in mouse central and peripheral nervous systems

    Directory of Open Access Journals (Sweden)

    Keizo eHirano

    2012-08-01

    Full Text Available The generation of complex neural circuits depends on the correct wiring of neurons with diverse individual characteristics. To understand the complexity of the nervous system, the molecular mechanisms for specifying the identity and diversity of individual neurons must be elucidated. The clustered protocadherins (Pcdh in mammals consist of approximately 50 Pcdh genes (Pcdh-α, Pcdh-β, and Pcdh-γ that encode cadherin-family cell surface adhesion proteins. Individual neurons express a random combination of Pcdh-α and Pcdh-γ, whereas the expression patterns for the Pcdh-β genes, 22 one-exon genes in mouse, are not fully understood. Here we show that the Pcdh-β genes are expressed in a 3’-polyadenylated form in mouse brain. In situ hybridization using a pan-Pcdh-β probe against a conserved Pcdh-β sequence showed widespread labeling in the brain, with prominent signals in the olfactory bulb, hippocampus, and cerebellum. In situ hybridization with specific probes for individual Pcdh-β genes showed their expression to be scattered in Purkinje cells from P10 to P150. The scattered expression patterns were confirmed by performing a newly developed single-cell 3’-RACE analysis of Purkinje cells, which clearly demonstrated that the Pcdh-β genes are expressed monoallelically and combinatorially in individual Purkinje cells. Scattered expression patterns of individual Pcdh-β genes were also observed in pyramidal neurons in the hippocampus and cerebral cortex, neurons in the trigeminal and dorsal root ganglion, GABAergic interneurons, and cholinergic neurons. Our results extend previous observations of diversity at the single-neuron level generated by Pcdh expression and suggest that the Pcdh-β cluster genes contribute to specifying the identity and diversity of individual neurons.

  13. Mixed Methods Case Study of Generational Patterns in Responses to Shame and Guilt

    Science.gov (United States)

    Ng, Tony

    2013-01-01

    Moral socialization and moral learning are antecedents of moral motivation. As many as 4 generations interact in workplace and education settings; hence, a deeper understanding of the moral motivation of members of those generations is needed. The purpose of this convergent mixed methods case study was to understand the moral motivation of 5…

  14. Spatio-Temporal Stochastic Pattern Generator for ensemble prediction and ensemble data assimilation in geophysical applications

    CERN Document Server

    Tsyrulnikov, Michael

    2016-01-01

    A generator of spatio-temporal pseudo-random Gaussian fields that satisfy the "proportionality of scales" property (Tsyroulnikov 2001) is presented. The generator is a third-order in time stochastic differential equation with a pseudo-differential spatial operator defined on a limited area domain in Cartesian coordinate system. The spatial covariance functions of the generated fields belong to the Mat\\'ern class. The spatio-temporal covariances are non-separable. A spectral-space numerical solver is implemented and accelerated exploiting properties of real-world geophysical fields, in particular, smoothness of their spatial spectra. The generator is designed to simulate additive or multiplicative, or other spatio-temporal perturbations that represent uncertainties in numerical prediction models in geophysics. The program code of the generator is publicly available.

  15. Data Series Generation for CPS Plants Simulation; Generacion de Series para Simulacion de Centrales Termosolares

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, G.; Valenzuela, R. X.; Ramirez, L.; Polo, J.

    2014-02-01

    Due to the problems with the environment and other issues arising from the use of oil as the main source of energy, such as unstable politics and economics, there has been a growing interest in the development of alternative forms of energy over the last few years. In this field, the sun is a fundamental element, since any form of existing energy derives from it, directly or indirectly. Taking in to consideration all of these renewable energies, we have decided to focus on solar thermal energy, seeing as it will play a vital role in the future particularly in countries such as Spain that have great solar potential. Amid this form of renewable energy, the parabolic cylinder concentrator power plants are technologies with one of the most promising futures. Power plants with sufficient technological developments to compete with the other forms of energies and that have an extensive margin for improvement. These power plants are the subject of the investigations carried out in this project. This project will try to establish and standardize some of the necessary procedures for the process of data prior to the simulation of energy with these types of power plants. The final objective is to help create a regulation where all these procedures are gathered together, and one that can be used as a guide for future investigations on the viability of these power plants. To achieve this, this project is comprised of various phases where different necessary investigations will be carried out in order to define the different points of the regulation. Firstly, the different casuistries will be investigated when analyzing the behavior of the estimated input data. At this stage, the selected variable (global or direct radiation), as well as the procedure used for the generation of the Monthly Reference Value, will be taken in to account, differentiating it in to two different typologies. The best method for the adjustment of the estimated data obtained from the satellite images will

  16. Stationary wave patterns generated by an impurity moving with supersonic velocity through a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Formation of stationary three-dimensional (3D) wave patterns generated by a small pointlike impurity moving through a Bose-Einstein condensate with supersonic velocity is studied. Asymptotic formulae for a stationary far-field density distribution are obtained. Comparison with the three-dimensional numerical simulations demonstrates that these formulae are accurate enough already at the distances from the obstacle equal to a few wavelengths.

  17. Detection of planets in extremely weak central perturbation microlensing events via next-generation ground-based surveys

    CERN Document Server

    Chung, Sun-Ju; Koo, Jae-Rim

    2014-01-01

    Even though the recently discovered high-magnification event MOA-2010-BLG-311 had complete coverage over the peak, confident planet detection did not happen due to extremely weak central perturbations (fractional deviations of $\\lesssim 2\\%$). For confident detection of planets in extremely weak central perturbation (EWCP) events, it is necessary to have both high cadence monitoring and high photometric accuracy better than those of current follow-up observation systems.The next-generation ground-based observation project, KMTNet (Korea Microlensing Telescope Network), satisfies the conditions. We estimate the probability of occurrence of EWCP events with fractional deviations of $\\leq 2\\%$ in high-magnification events and the efficiency of detecting planets in the EWCP events using the KMTNet. From this study, we find that the EWCP events occur with a frequency of $> 50\\%$ in the case of $\\lesssim 100\\ M_{\\rm E}$ planets with separations of $0.2\\ {\\rm AU} \\lesssim d \\lesssim 20\\ {\\rm AU}$. We find that for m...

  18. Gene Mutation Profiles in Primary Diffuse Large B Cell Lymphoma of Central Nervous System: Next Generation Sequencing Analyses

    Directory of Open Access Journals (Sweden)

    Milena Todorovic Balint

    2016-05-01

    Full Text Available The existence of a potential primary central nervous system lymphoma-specific genomic signature that differs from the systemic form of diffuse large B cell lymphoma (DLBCL has been suggested, but is still controversial. We investigated 19 patients with primary DLBCL of central nervous system (DLBCL CNS using the TruSeq Amplicon Cancer Panel (TSACP for 48 cancer-related genes. Next generation sequencing (NGS analyses have revealed that over 80% of potentially protein-changing mutations were located in eight genes (CTNNB1, PIK3CA, PTEN, ATM, KRAS, PTPN11, TP53 and JAK3, pointing to the potential role of these genes in lymphomagenesis. TP53 was the only gene harboring mutations in all 19 patients. In addition, the presence of mutated TP53 and ATM genes correlated with a higher total number of mutations in other analyzed genes. Furthermore, the presence of mutated ATM correlated with poorer event-free survival (EFS (p = 0.036. The presence of the mutated SMO gene correlated with earlier disease relapse (p = 0.023, inferior event-free survival (p = 0.011 and overall survival (OS (p = 0.017, while mutations in the PTEN gene were associated with inferior OS (p = 0.048. Our findings suggest that the TP53 and ATM genes could be involved in the molecular pathophysiology of primary DLBCL CNS, whereas mutations in the PTEN and SMO genes could affect survival regardless of the initial treatment approach.

  19. Gene Mutation Profiles in Primary Diffuse Large B Cell Lymphoma of Central Nervous System: Next Generation Sequencing Analyses

    Science.gov (United States)

    Todorovic Balint, Milena; Jelicic, Jelena; Mihaljevic, Biljana; Kostic, Jelena; Stanic, Bojana; Balint, Bela; Pejanovic, Nadja; Lucic, Bojana; Tosic, Natasa; Marjanovic, Irena; Stojiljkovic, Maja; Karan-Djurasevic, Teodora; Perisic, Ognjen; Rakocevic, Goran; Popovic, Milos; Raicevic, Sava; Bila, Jelena; Antic, Darko; Andjelic, Bosko; Pavlovic, Sonja

    2016-01-01

    The existence of a potential primary central nervous system lymphoma-specific genomic signature that differs from the systemic form of diffuse large B cell lymphoma (DLBCL) has been suggested, but is still controversial. We investigated 19 patients with primary DLBCL of central nervous system (DLBCL CNS) using the TruSeq Amplicon Cancer Panel (TSACP) for 48 cancer-related genes. Next generation sequencing (NGS) analyses have revealed that over 80% of potentially protein-changing mutations were located in eight genes (CTNNB1, PIK3CA, PTEN, ATM, KRAS, PTPN11, TP53 and JAK3), pointing to the potential role of these genes in lymphomagenesis. TP53 was the only gene harboring mutations in all 19 patients. In addition, the presence of mutated TP53 and ATM genes correlated with a higher total number of mutations in other analyzed genes. Furthermore, the presence of mutated ATM correlated with poorer event-free survival (EFS) (p = 0.036). The presence of the mutated SMO gene correlated with earlier disease relapse (p = 0.023), inferior event-free survival (p = 0.011) and overall survival (OS) (p = 0.017), while mutations in the PTEN gene were associated with inferior OS (p = 0.048). Our findings suggest that the TP53 and ATM genes could be involved in the molecular pathophysiology of primary DLBCL CNS, whereas mutations in the PTEN and SMO genes could affect survival regardless of the initial treatment approach. PMID:27164089

  20. The Identification of Discriminating Patterns from 16S rRNA Gene to Generate Signature for Bacillus Genus.

    Science.gov (United States)

    More, Ravi P; Purohit, Hemant J

    2016-08-01

    The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification. PMID:27104769

  1. The Identification of Discriminating Patterns from 16S rRNA Gene to Generate Signature for Bacillus Genus.

    Science.gov (United States)

    More, Ravi P; Purohit, Hemant J

    2016-08-01

    The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification.

  2. High-harmonic generation from a coherent superposition of electronic states: Controlling interference patterns via short and long quantum orbits

    Science.gov (United States)

    Chelkowski, Szczepan; Bredtmann, Timm; Bandrauk, André D.

    2013-09-01

    Laser pump-probe schemes are explored numerically from a molecular time-dependent Schrödinger equation for monitoring attosecond electron motion by high-order-harmonic generation (HHG) from a coherent superposition of electronic states. Varying the time delay between the probe and pump pulse on an attosecond time scale alters the HHG signal, leading to universal interference patterns. By using an extended three-step recollision model, we show that various regular interference patterns in the HHG spectra, including continuous harmonic frequency redshifts as a function of pump-probe delay, are related to interference between specific pairs of short or long quantum orbits. For small excited-state population (regime A), interferences are controlled by electron-tunneling times, whereas for equal populations (regime B), recollision time control dominates thus allowing for control of the HHG process by the pump-probe delay time and by electron-state populations. We show that each specific pattern is closely related to the interference between pairs of specific (short or long) quantum orbits originating from a specific electron bound state. One can generate a specific pattern by varying the populations in the coherent superposition, the laser intensity, wavelength, and ionization potential of the electronic states.

  3. Near-field to far-field characterization of speckle patterns generated by disordered nanomaterials

    CERN Document Server

    Parigi, Valentina; Binard, Guillaume; Bourdillon, Céline; Maître, Agnès; Carminati, Rémi; Krachmalnicoff, Valentina; De Wilde, Yannick

    2016-01-01

    We study the intensity spatial correlation function of optical speckle patterns above a disordered dielectric medium in the multiple scattering regime. The intensity distributions are recorded by scanning near-field optical microscopy (SNOM) with sub-wavelength spatial resolution at variable distances from the surface in a range which spans continuously from the near-field (distance $ \\ll \\lambda $) to the far-field regime (distance $\\gg \\lambda $). The non-universal behavior at sub-wavelength distances reveals the connection between the near-field speckle pattern and the internal structure of the medium.

  4. Near-field to far-field characterization of speckle patterns generated by disordered nanomaterials.

    Science.gov (United States)

    Parigi, Valentina; Perros, Elodie; Binard, Guillaume; Bourdillon, Céline; Maître, Agnès; Carminati, Rémi; Krachmalnicoff, Valentina; De Wilde, Yannick

    2016-04-01

    We study the intensity spatial correlation function of optical speckle patterns above a disordered dielectric medium in the multiple scattering regime. The intensity distributions are recorded by scanning near-field optical microscopy (SNOM) with sub-wavelength spatial resolution at variable distances from the surface in a range which spans continuously from the near-field (distance ≪ λ) to the far-field regime (distance ≫ λ). The non-universal behavior at sub-wavelength distances reveals the connection between the near-field speckle pattern and the internal structure of the medium. PMID:27136995

  5. Generation of a reference radiation pattern of string instruments using automatic excitation and acoustic centering.

    Science.gov (United States)

    Shabtai, Noam R; Behler, Gottfried; Vorländer, Michael

    2015-11-01

    Radiation patterns of musical instruments are important for the understanding of music perception in concert halls, and may be used to improve the plausibility of virtual acoustic systems. Many attempts have been performed to measure the spatial response of musical instruments using surrounding spherical microphone arrays with a limited number of microphones. This work presents a high-resolution spatial sampling of the radiation pattern of an electrically excited violin, and addresses technical problems that arise due to mechanical reasons of the excitation apparatus using acoustic centering.

  6. Impact of cercal air currents on singing motor pattern generation in the cricket (Gryllus bimaculatus DeGeer).

    Science.gov (United States)

    Jacob, Pedro F; Hedwig, Berthold

    2015-11-01

    The cercal system of crickets detects low-frequency air currents produced by approaching predators and self-generated air currents during singing, which may provide sensory feedback to the singing motor network. We analyzed the effect of cercal stimulation on singing motor pattern generation to reveal the response of a singing interneuron to predator-like signals and to elucidate the possible role of self-generated air currents during singing. In fictive singing males, we recorded an interneuron of the singing network while applying air currents to the cerci; additionally, we analyzed the effect of abolishing the cercal system in freely singing males. In fictively singing crickets, the effect of short air stimuli is either to terminate prematurely or to lengthen the interchirp interval, depending on their phase in the chirp cycle. Within our stimulation paradigm, air stimuli of different velocities and durations always elicited an inhibitory postsynaptic potential in the singing interneuron. Current injection in the singing interneuron elicited singing motor activity, even during the air current-evoked inhibitory input from the cercal pathway. The disruptive effects of air stimuli on the fictive singing pattern and the inhibitory response of the singing interneuron point toward the cercal system being involved in initiating avoidance responses in singing crickets, according to the established role of cerci in a predator escape pathway. After abolishing the activity of the cercal system, the timing of natural singing activity was not significantly altered. Our study provides no evidence that self-generated cercal sensory activity has a feedback function for singing motor pattern generation.

  7. Infant dietary patterns and bone mass in childhood: the Generation R Study

    NARCIS (Netherlands)

    E.H. van den Hooven (Edith); D.H.M. Heppe (Denise); J.C. Kiefte-de Jong (Jessica); M.C. Medina-Gomez (Carolina); H.A. Moll (Henriëtte); A. Hofman (Albert); V.W.V. Jaddoe (Vincent); F. Rivadeneira Ramirez (Fernando); O.H. Franco (Oscar)

    2015-01-01

    textabstractConclusions: An infant dietary pattern characterized by high intakes of dairy and cheese, whole grains, and eggs is positively associated with bone development in childhood. Further research is needed to investigate the consequences for bone health in later life.Results: Higher adherence

  8. A column generation-based heuristic for rostering with work patterns

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Dohn, Anders Høeg; Range, Troels Martin;

    2012-01-01

    This paper addresses the Ground Crew Rostering Problem with Work Patterns, an important manpower planning problem arising in the ground operations of airline companies. We present a cutting stock-based integer programming formulation of the problem and describe a powerful heuristic decomposition...

  9. Assembly-free genome comparison based on next-generation sequencing reads and variable length patterns

    OpenAIRE

    Comin, Matteo; Schimd, Michele

    2014-01-01

    Background With the advent of Next-Generation Sequencing technologies (NGS), a large amount of short read data has been generated. If a reference genome is not available, the assembly of a template sequence is usually challenging because of repeats and the short length of reads. When NGS reads cannot be mapped onto a reference genome alignment-based methods are not applicable. However it is still possible to study the evolutionary relationship of unassembled genomes based on NGS data. Results...

  10. Generation and use of observational data patterns in the evaluation of data quality for AmeriFlux and FLUXNET

    Science.gov (United States)

    Pastorello, G.; Agarwal, D.; Poindexter, C.; Papale, D.; Trotta, C.; Ribeca, A.; Canfora, E.; Faybishenko, B.; Gunter, D.; Chu, H.

    2015-12-01

    The fluxes-measuring sites that are part of AmeriFlux are operated and maintained in a fairly independent fashion, both in terms of scientific goals and operational practices. This is also the case for most sites from other networks in FLUXNET. This independence leads to a degree of heterogeneity in the data sets collected at the sites, which is also reflected in data quality levels. The generation of derived data products and data synthesis efforts, two of the main goals of these networks, are directly affected by the heterogeneity in data quality. In a collaborative effort between AmeriFlux and ICOS, a series of quality checks are being conducted for the data sets before any network-level data processing and product generation take place. From these checks, a set of common data issues were identified, and are being cataloged and classified into data quality patterns. These patterns are now being used as a basis for implementing automation for certain data quality checks, speeding up the process of applying the checks and evaluating the data. Currently, most data checks are performed individually in each data set, requiring visual inspection and inputs from a data curator. This manual process makes it difficult to scale the quality checks, creating a bottleneck for the data processing. One goal of the automated checks is to free up time of data curators so they can focus on new or less common issues. As new issues are identified, they can also be cataloged and classified, extending the coverage of existing patterns or potentially generating new patterns, helping both improve existing automated checks and create new ones. This approach is helping make data quality evaluation faster, more systematic, and reproducible. Furthermore, these patterns are also helping with documenting common causes and solutions for data problems. This can help tower teams with diagnosing problems in data collection and processing, and also in correcting historical data sets. In this

  11. Sustainability Assessment of a Self-Consumption Wood-Energy Chain on Small Scale for Heat Generation in Central Italy

    Directory of Open Access Journals (Sweden)

    Stefano Verani

    2015-06-01

    Full Text Available The sustainability of a small-scale self-consumption wood-energy chain for heat generation in central Italy was analyzed from a technical, economic and energetic point of view. A micro-chain was developed within the CRA-ING farm at Monterotondo (Rome, Italy: The purpose of this system was to produce biomass for supplying a heating plant within the CRA-ING property as a substitute for diesel fuel. A poplar short rotation coppice, established with clones AF2, AF6 and Monviso, fed the micro-chain. The rotation was biennial. The average plantation production (Mgd.m.·ha−1·year−1 was 10.2, with a maximum of 13.53 for the twin-rows AF2 and a minimum of 8.00 for the single-row Monviso. The economic assessment was based on the Net Present Value (NPV method and the equivalent annuity cost, and found an average saving of 15.60 €·GJ−1 of heat generated by the wood chips heating system in comparison with the diesel heating system over a 10 year lifetime of the thermal power plant. The energy assessment of the poplar plantation, carried out using the Gross Energy Requirements method, reported an energy output/input ratio of 12.3. The energy output/input ratio of the whole micro-chain was 4.5.

  12. Temporal and spatial patterns in wind stress and wind stress curl over the central Southern California Bight

    Science.gov (United States)

    Noble, Marlene A.; Rosenberger, Kurt J.; Rosenfeld, Leslie K.; Robertson, George L.

    2012-04-01

    In 2001, the U.S. Geological Survey, together with several other federal and municipal agencies, began a series of field programs to determine along and cross-shelf transport patterns over the continental shelves in the central Southern California Bight. As a part of these programs, moorings that monitor winds were deployed off the Palos Verdes peninsula and within San Pedro Bay for six 3-4 month summer and winter periods between 2001 and 2008. In addition, nearly continuous records of winds for this 7-year period were obtained from a terrestrial site at the coast and from a basin site offshore of the long-term coastal site. The mean annual winds are downcoast at all sites. The alongshelf components of wind stress, which are the largest part of the low-frequency wind stress fields, are well correlated between basin, shelf and coastal sites. On average, the amplitude of alongshelf fluctuations in wind stress are 3-4 times larger over the offshore basin, compared to the coastal site, irrespective of whether the fluctuations represent the total, or just the correlated portion of the wind stress field. The curl in the large-scale wind stress tends to be positive, especially in the winter season when the mean wind stress is downcoast and larger at the offshore basin site than at the beach. However, since the fluctuation in wind stress amplitudes are usually larger than the mean, periods of weak negative curl do occur, especially in the summer season when the largest normalized differences in the amplitude of wind stress fluctuations are found in the nearshore region of the coastal ocean. Even though the low-frequency wind stress field is well-correlated over the continental shelf and offshore basins, out to distances of 35 km or more from the coast, winds even 10 km inshore of the beach do not represent the coastal wind field, at least in the summer months. The seasonal changes in the spatial structures in wind stress amplitudes suggest that an assessment of the

  13. Temporal and spatial patterns in wind stress and wind stress curl over the central Southern California Bight

    Science.gov (United States)

    Noble, Marlene A.; Rosenberger, Kurt J.; Rosenfeld, Leslie K.; Robertson, George L.

    2012-01-01

    In 2001, the U.S. Geological Survey, together with several other federal and municipal agencies, began a series of field programs to determine along and cross-shelf transport patterns over the continental shelves in the central Southern California Bight. As a part of these programs, moorings that monitor winds were deployed off the Palos Verdes peninsula and within San Pedro Bay for six 3–4 month summer and winter periods between 2001 and 2008. In addition, nearly continuous records of winds for this 7-year period were obtained from a terrestrial site at the coast and from a basin site offshore of the long-term coastal site. The mean annual winds are downcoast at all sites. The alongshelf components of wind stress, which are the largest part of the low-frequency wind stress fields, are well correlated between basin, shelf and coastal sites. On average, the amplitude of alongshelf fluctuations in wind stress are 3–4 times larger over the offshore basin, compared to the coastal site, irrespective of whether the fluctuations represent the total, or just the correlated portion of the wind stress field. The curl in the large-scale wind stress tends to be positive, especially in the winter season when the mean wind stress is downcoast and larger at the offshore basin site than at the beach. However, since the fluctuation in wind stress amplitudes are usually larger than the mean, periods of weak negative curl do occur, especially in the summer season when the largest normalized differences in the amplitude of wind stress fluctuations are found in the nearshore region of the coastal ocean. Even though the low-frequency wind stress field is well-correlated over the continental shelf and offshore basins, out to distances of 35 km or more from the coast, winds even 10 km inshore of the beach do not represent the coastal wind field, at least in the summer months. The seasonal changes in the spatial structures in wind stress amplitudes suggest that an assessment of the

  14. Dust generation and drought patterns in Africa from helium-4 in a modern Cape Verde coral

    Science.gov (United States)

    Mukhopadhyay, S.; Kreycik, P.

    2008-10-01

    We show that helium-4 (4He) concentrations in a modern Porites coral from Cape Verde provides a robust reconstruction of mineral dust loading over the Eastern Tropical Atlantic from mid-1950's to mid-1990's. The 4He record demonstrates pronounced increases in dust emission from North Africa associated with the severe droughts in the Sahel. Our record provides direct evidence that dust emission rates in the 1950's, prior to the onset of the Sahel droughts, were a factor of nine lower than during 1980-84. This large change in dust emission rate indicates global aerosol contents would have increased by ~45% over this period, which may have contributed to a reduction in solar radiation reaching the Earth's surface. We find that dust emission from North Africa is most closely related to drought patterns, rather than to changes in atmospheric circulation patterns resulting from climate oscillations, such as North Atlantic Oscillations and El Nino/Southern Oscillation.

  15. The Importance of Peers: Assimilation Patterns among Second-generation Turkish Immigrants in Western Europe

    OpenAIRE

    Ali, S; Fokkema, T.

    2015-01-01

    The two dominant approaches to immigrant assimilation, segmented assimilation and "new" assimilation theories, have been successful at reporting and analyzing between-group differences in assimilation patterns. However, studies of assimilation generally do not address differences at the individual level. Current theories of assimilation cannot answer the simple question that gets to the heart of individual-level differences: how do you account for siblings in the same family assimilating in d...

  16. Spatial organization and state-dependent mechanisms for respiratory rhythm and pattern generation

    OpenAIRE

    Rybak, Ilya A.; Abdala, Ana P.L.; Markin, Sergey N.; Paton, Julian F. R.; Smith, Jeffrey C.

    2007-01-01

    The brainstem respiratory network can operate in multiple functional states engaging different state-dependent neural mechanisms. These mechanisms were studied in the in situ perfused rat brainstem–spinal cord preparation using sequential brainstem transections and administration of riluzole, a pharmacological blocker of persistent sodium current (INaP). Dramatic transformations in the rhythmogenic mechanisms and respiratory motor pattern were observed after removal of the pons and subsequent...

  17. Infant dietary patterns and bone mass in childhood: the Generation R Study

    OpenAIRE

    van den Hooven, E. H.; Heppe, D. H. M.; Kiefte-de Jong, J.C.; Medina-Gomez, C; Moll, H.A.; Hofman, A.; Jaddoe, V. W. V.; Rivadeneira, F.; Franco, O. H.

    2015-01-01

    Summary Early life nutrition affects peak bone mass attainment. In this prospective cohort study, children with high adherence to a “dairy and whole grains” pattern in infancy had higher bone mineral density at the age of 6 years. Although the observed effects are small, our study provides insight into mechanisms linking early nutrition to bone acquisition in childhood. Introduction Nutrition in early life may affect peak bone mass attainment. Previous studies on childhood nutrition and skele...

  18. Programming Surface Energy Driven Marangoni Convection in Polymer Thin Films to Generate Topographic Patterns

    Science.gov (United States)

    Kim, Chae Bin; Janes, Dustin; Arshad, Talha; Katzenstein, Joshua; Prisco, Nathan; McGuffin, Dana; Bonnecaze, Roger; Ellison, Christopher

    2015-03-01

    The Marangoni effect describes how fluid flows in response to gradients in surface energy. We recently developed a method for photochemically preprograming spatial surface energy patterns in glassy polystyrene (PS) thin films. UV irradiation through a mask selectively dehydrogenates the PS, thus increasing surface energy in the UV exposed regions compared to the unexposed regions. After heating the film to the liquid state, transport of polymer occurs from regions of low surface energy to regions of high surface energy. This method can be harnessed to rapidly manufacture polymer films possessing prescribed three-dimensional topographies reflective of the original light exposure pattern. To quantify and verify this phenomenon, a theoretical model that gives a more thorough understanding of the physics of this process, its limits and ways to apply it efficiently for various target metrics will also be presented along with comparisons between theoretical predictions and experimental observations. Finally, while PS dehydrogenation can be used to produce a variety of topographical patterns, judicious selection of the photosensitizing compounds in an otherwise transparent polymer expands the use of this method to more readily available light sources.

  19. Consumption patterns and household hazardous solid waste generation in an urban settlement in Mexico

    International Nuclear Information System (INIS)

    Mexico is currently facing a crisis in the waste management field. Some efforts have just commenced in urban and in rural settlements, e.g., conversion of open dumps into landfills, a relatively small composting culture, and implementation of source separation and plastic recycling strategies. Nonetheless, the high heterogeneity of components in the waste, many of these with hazardous properties, present the municipal collection services with serious problems, due to the risks to the health of the workers and to the impacts to the environment as a result of the inadequate disposition of these wastes. A generation study in the domestic sector was undertaken with the aim of finding out the composition and the generation rate of household hazardous waste (HHW) produced at residences. Simultaneously to the generation study, a socioeconomic survey was applied to determine the influence of income level on the production of HHW. Results from the solid waste generation analysis indicated that approximately 1.6% of the waste stream consists of HHW. Correspondingly, it was estimated that in Morelia, a total amount of 442 ton/day of domestic waste are produced, including 7.1 ton of HHW per day. Furthermore, the overall amount of HHW is not directly related to income level, although particular byproducts do correlate. However, an important difference was observed, as the brands and the presentation sizes of goods and products used in each socioeconomic stratum varied

  20. Consumption patterns and household hazardous solid waste generation in an urban settlement in México.

    Science.gov (United States)

    Otoniel, Buenrostro Delgado; Liliana, Márquez-Benavides; Francelia, Pinette Gaona

    2008-01-01

    Mexico is currently facing a crisis in the waste management field. Some efforts have just commenced in urban and in rural settlements, e.g., conversion of open dumps into landfills, a relatively small composting culture, and implementation of source separation and plastic recycling strategies. Nonetheless, the high heterogeneity of components in the waste, many of these with hazardous properties, present the municipal collection services with serious problems, due to the risks to the health of the workers and to the impacts to the environment as a result of the inadequate disposition of these wastes. A generation study in the domestic sector was undertaken with the aim of finding out the composition and the generation rate of household hazardous waste (HHW) produced at residences. Simultaneously to the generation study, a socioeconomic survey was applied to determine the influence of income level on the production of HHW. Results from the solid waste generation analysis indicated that approximately 1.6% of the waste stream consists of HHW. Correspondingly, it was estimated that in Morelia, a total amount of 442ton/day of domestic waste are produced, including 7.1ton of HHW per day. Furthermore, the overall amount of HHW is not directly related to income level, although particular byproducts do correlate. However, an important difference was observed, as the brands and the presentation sizes of goods and products used in each socioeconomic stratum varied.

  1. Exact distribution of a pattern in a set of random sequences generated by a Markov source: applications to biological data

    Directory of Open Access Journals (Sweden)

    Regad Leslie

    2010-01-01

    Full Text Available Abstract Background In bioinformatics it is common to search for a pattern of interest in a potentially large set of rather short sequences (upstream gene regions, proteins, exons, etc.. Although many methodological approaches allow practitioners to compute the distribution of a pattern count in a random sequence generated by a Markov source, no specific developments have taken into account the counting of occurrences in a set of independent sequences. We aim to address this problem by deriving efficient approaches and algorithms to perform these computations both for low and high complexity patterns in the framework of homogeneous or heterogeneous Markov models. Results The latest advances in the field allowed us to use a technique of optimal Markov chain embedding based on deterministic finite automata to introduce three innovative algorithms. Algorithm 1 is the only one able to deal with heterogeneous models. It also permits to avoid any product of convolution of the pattern distribution in individual sequences. When working with homogeneous models, Algorithm 2 yields a dramatic reduction in the complexity by taking advantage of previous computations to obtain moment generating functions efficiently. In the particular case of low or moderate complexity patterns, Algorithm 3 exploits power computation and binary decomposition to further reduce the time complexity to a logarithmic scale. All these algorithms and their relative interest in comparison with existing ones were then tested and discussed on a toy-example and three biological data sets: structural patterns in protein loop structures, PROSITE signatures in a bacterial proteome, and transcription factors in upstream gene regions. On these data sets, we also compared our exact approaches to the tempting approximation that consists in concatenating the sequences in the data set into a single sequence. Conclusions Our algorithms prove to be effective and able to handle real data sets with

  2. Automated Learning of Subcellular Variation among Punctate Protein Patterns and a Generative Model of Their Relation to Microtubules.

    Directory of Open Access Journals (Sweden)

    Gregory R Johnson

    2015-12-01

    Full Text Available Characterizing the spatial distribution of proteins directly from microscopy images is a difficult problem with numerous applications in cell biology (e.g. identifying motor-related proteins and clinical research (e.g. identification of cancer biomarkers. Here we describe the design of a system that provides automated analysis of punctate protein patterns in microscope images, including quantification of their relationships to microtubules. We constructed the system using confocal immunofluorescence microscopy images from the Human Protein Atlas project for 11 punctate proteins in three cultured cell lines. These proteins have previously been characterized as being primarily located in punctate structures, but their images had all been annotated by visual examination as being simply "vesicular". We were able to show that these patterns could be distinguished from each other with high accuracy, and we were able to assign to one of these subclasses hundreds of proteins whose subcellular localization had not previously been well defined. In addition to providing these novel annotations, we built a generative approach to modeling of punctate distributions that captures the essential characteristics of the distinct patterns. Such models are expected to be valuable for representing and summarizing each pattern and for constructing systems biology simulations of cell behaviors.

  3. Generation of Homogeneous and Patterned Electron Beams using a Microlens Array Laser-Shaping Technique

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, Aliaksei [NICADD, DeKalb; Edstrom, Dean [Fermilab; Gai, Wei [Argonne, HEP; Ha, Gwanghui [Argonne, HEP; Piot, Philippe [NICADD, DeKalb; Power, John [Argonne, HEP; Qiang, Gao [Unlisted, CN; Ruan, Jinhao [Fermilab; Santucci, James [Fermilab; Wisniewski, Eric [Argonne, HEP

    2016-06-01

    In photocathodes the achievable electron-beam parameters are controlled by the laser used to trigger the photoemission process. Non-ideal laser distribution hampers the final beam quality. Laser inhomogeneities, for instance, can be "amplified" by space-charge force and result in fragmented electron beams. To overcome this limitation laser shaping methods are routinely employed. In the present paper we demonstrate the use of simple microlens arrays to dramatically improve the transverse uniformity. We also show that this arrangement can be used to produce transversely-patterned electron beams. Our experiments are carried out at the Argonne Wakefield Accelerator facility.

  4. Generation of predictive price and trading volume patterns in a model of dynamically evolving free market supply and demand

    Directory of Open Access Journals (Sweden)

    J. K. Wang

    2001-01-01

    Full Text Available I present a model of stock market price fluctuations incorporating effects of share supply as a history-dependent function of previous purchases and share demand as a function of price deviation from moving averages. Price charts generated show intervals of oscillations switching amplitude and frequency suddenly in time, forming price and trading volume patterns well-known in market technical analysis. Ultimate price trends agree with traditional predictions for specific patterns. The consideration of dynamically evolving supply and demand in this model resolves the apparent contradiction with the Efficient Market Hypothesis: perceptions of imprecise equity values by a world of investors evolve over non-negligible periods of time, with dependence on price history.

  5. The spectral and polarization characteristics of the nonspherically decaying radiation generated by polarization currents with superluminally rotating distribution patterns

    CERN Document Server

    Ardavan, H; Singleton, J

    2003-01-01

    We present a theoretical study of the emission from a superluminal polarization current whose distribution pattern rotates (with an angular frequency $\\omega$) and oscillates (with a frequency $\\Omega $) at the same time, and which comprises both poloidal and toroidal components. This type of polarization current is found in recent practical machines designed to investigate superluminal emission. We find that the superluminal motion of the distribution pattern of the emitting current generates localized electromagnetic waves that do not decay spherically, i.e. that do not have an intensity diminishing like ${R_P}^{-2}$ with the distance $R_P$ from their source. The nonspherical decay of the focused wave packets that are emitted by the polarization currents does not contravene conservation of energy: the constructive interference of the constituent waves of such propagating caustics takes place within different solid angles on spheres of different radii ($R_P$) centred on the source. For a polarization current...

  6. Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

    KAUST Repository

    Hasheminejad, S. M.

    2016-01-05

    A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out for a Reynolds number based on the pattern wavelength (λ) of 3080. The results depict the onset, development and breakdown of the vortical structures within the flat plate boundary layer. Moreover, the effect of one spanwise array of holes with diameter of 0.2λ (=3 mm) was examined. This investigation was done on two different flat plates with holes placed at the location x/λ = 2 downstream of the troughs and peaks. The presence of holes after troughs does not show any significant effect on the vortical structures. However, the plate with holes after peaks noticeably delays the vortex breakdown. In this case, the “mushroom-like” vortices move away from the wall and propagate downstream with stable vortical structures. The vortex growth is halted further downstream but start to tilt aside.

  7. Synaptic signal streams generated by ex vivo neuronal networks contain non-random, complex patterns.

    Science.gov (United States)

    Lee, Sangmook; Zemianek, Jill M; Shultz, Abraham; Vo, Anh; Maron, Ben Y; Therrien, Mikaela; Courtright, Christina; Guaraldi, Mary; Yanco, Holly A; Shea, Thomas B

    2014-11-01

    Cultured embryonic neurons develop functional networks that transmit synaptic signals over multiple sequentially connected neurons as revealed by multi-electrode arrays (MEAs) embedded within the culture dish. Signal streams of ex vivo networks contain spikes and bursts of varying amplitude and duration. Despite the random interactions inherent in dissociated cultures, neurons are capable of establishing functional ex vivo networks that transmit signals among synaptically connected neurons, undergo developmental maturation, and respond to exogenous stimulation by alterations in signal patterns. These characteristics indicate that a considerable degree of organization is an inherent property of neurons. We demonstrate herein that (1) certain signal types occur more frequently than others, (2) the predominant signal types change during and following maturation, (3) signal predominance is dependent upon inhibitory activity, and (4) certain signals preferentially follow others in a non-reciprocal manner. These findings indicate that the elaboration of complex signal streams comprised of a non-random distribution of signal patterns is an emergent property of ex vivo neuronal networks.

  8. Temporal patterns in Saturnidae (silk moth) and Sphingidae (hawk moth) assemblages in protected forests of central Uganda

    OpenAIRE

    Akite, Perpetra; Telford, Richard; Waring, Paul; Akol, Anne M.; Vandvik, Vigdis

    2015-01-01

    Forest-dependent biodiversity is threatened throughout the tropics by habitat loss and land-use intensification of the matrix habitats. We resampled historic data on two moth families, known to play central roles in many ecosystem processes, to evaluate temporal changes in species richness and community structure in three protected forests in central Uganda in a rapidly changing matrix. Our results show some significant declines in the moth species richness and the relative abundance and rich...

  9. Student-generated questions during chemistry lectures: Patterns, self-appraisals, and relations with motivational beliefs and achievement

    Science.gov (United States)

    Bergey, Bradley W.

    Self-generated questions are a central mechanism for learning, yet students' questions are often infrequent during classroom instruction. As a result, little is known about the nature of student questioning during typical instructional contexts such as listening to a lecture, including the extent and nature of student-generated questions, how students evaluate their questions, and the relations among questions, motivations, and achievement. This study examined the questions undergraduate students (N = 103) generated during 8 lectures in an introductory chemistry course. Students recorded and appraised their question in daily question logs and reported lecture-specific self-efficacy beliefs. Self-efficacy, personal interest, goal orientations, and other motivational self-beliefs were measured before and after the unit. Primary analyses included testing path models, multiple regressions, and latent class analyses. Overall, results indicated that several characteristics of student questioning during lectures were significantly related to various motivations and achievement. Higher end-of-class self-efficacy was associated with fewer procedural questions and more questions that reflected smaller knowledge deficits. Lower exam scores were associated with questions reflecting broader knowledge deficits and students' appraisals that their questions had less value for others than for themselves. Individual goal orientations collectively and positively predicted question appraisals. The questions students generated and their relations with motivational variables and achievement are discussed in light of the learning task and academic context.

  10. Simple process-based simulators for generating spatial patterns of habitat loss and fragmentation: a review and introduction to the G-RaFFe model.

    Science.gov (United States)

    Pe'er, Guy; Zurita, Gustavo A; Schober, Lucia; Bellocq, Maria I; Strer, Maximilian; Müller, Michael; Pütz, Sandro

    2013-01-01

    Landscape simulators are widely applied in landscape ecology for generating landscape patterns. These models can be divided into two categories: pattern-based models that generate spatial patterns irrespective of the processes that shape them, and process-based models that attempt to generate patterns based on the processes that shape them. The latter often tend toward complexity in an attempt to obtain high predictive precision, but are rarely used for generic or theoretical purposes. Here we show that a simple process-based simulator can generate a variety of spatial patterns including realistic ones, typifying landscapes fragmented by anthropogenic activities. The model "G-RaFFe" generates roads and fields to reproduce the processes in which forests are converted into arable lands. For a selected level of habitat cover, three factors dominate its outcomes: the number of roads (accessibility), maximum field size (accounting for land ownership patterns), and maximum field disconnection (which enables field to be detached from roads). We compared the performance of G-RaFFe to three other models: Simmap (neutral model), Qrule (fractal-based) and Dinamica EGO (with 4 model versions differing in complexity). A PCA-based analysis indicated G-RaFFe and Dinamica version 4 (most complex) to perform best in matching realistic spatial patterns, but an alternative analysis which considers model variability identified G-RaFFe and Qrule as performing best. We also found model performance to be affected by habitat cover and the actual land-uses, the latter reflecting on land ownership patterns. We suggest that simple process-based generators such as G-RaFFe can be used to generate spatial patterns as templates for theoretical analyses, as well as for gaining better understanding of the relation between spatial processes and patterns. We suggest caution in applying neutral or fractal-based approaches, since spatial patterns that typify anthropogenic landscapes are often non

  11. Elucidating the role of topological pattern discovery and support vector machine in generating predictive models for Indian summer monsoon rainfall

    Science.gov (United States)

    Chattopadhyay, Manojit; Chattopadhyay, Surajit

    2016-10-01

    The present paper reports a study, where growing hierarchical self-organising map (GHSOM) has been applied to achieve a visual cluster analysis to the Indian rainfall dataset consisting of 142 years of Indian rainfall data so that the yearly rainfall can be segregated into small groups to visualise the pattern of clustering behaviour of yearly rainfall due to changes in monthly rainfall for each year. Also, through support vector machine (SVM), it has been observed that generation of clusters impacts positively on the prediction of the Indian summer monsoon rainfall. Results have been presented through statistical and graphical analyses.

  12. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  13. Evaluation of Ancient and Future Submarine Landslides Along the Central California Coast and Their Potential to Generate Tsunamis

    Science.gov (United States)

    Greene, H. G.; Paull, C. K.; Ward, S.; Ussler, W.; Maher, N. M.

    2001-12-01

    Submarine landslides have been located along the central California continental margin with the use of multibeam bathymetric and sub-bottom profiling data. These features are primarily concentrated on the lower continental slope and in submarine canyons. Recent evaluation of these landslides indicates that they are of various ages and types and formed in different ways. For example, the extensive slope failure morphology on the lower Point Sur slope range from subtle to very sharp geomorphic shapes that suggest these landslides have occurred over a long period of time. These landslides are large features (up to 215 km2) and form primarily from bottom-up processes in a retrogressive fashion. In contrast, some of the landslide scars located on flanks of submarine canyons appear youthful indicating recent activity. Several landslide scars and blocks are also located in the headward parts of Ascension and Monterey canyons. If these scars were generated by catastrophic slope failure, they are of the size (greater than 2 km2) and depth (lie at water depths less than 400 m) to have produced a tsunamis. Based on the presence of possible incipient crown scarps, we have also identified areas within the Ascension-Monterey submarine canyons system where wall failures may occur in the future. We are in the process of using computer simulations to assess the size and extent of tsunamis that these landslides might induce. On the horizon, we hope to develop a full probabilistic hazard estimate for landslide tsunamis run-up around Monterey Bay.

  14. Direct patterning of vortex generators on a fiber tip using a focused ion beam.

    Science.gov (United States)

    Vayalamkuzhi, Pramitha; Bhattacharya, Shanti; Eigenthaler, Ulrike; Keskinbora, Kahraman; Samlan, C T; Hirscher, Michael; Spatz, Joachim P; Viswanathan, Nirmal K

    2016-05-15

    The realization of spiral phase optical elements on the cleaved end of an optical fiber by focused ion beam milling is presented. A focused Ga+ ion beam with an acceleration voltage of 30 keV is used to etch continuous spiral phase plates and fork gratings directly on the tip of the fiber. The phase characteristics of the output beam generated by the fabricated structures measured via an interference experiment confirmed the presence of phase singularity in the output beam. The devices are expected to be promising candidates for all-fiber beam shaping and optical trapping applications.

  15. PLAP efficiently generates mature antigenic peptides in vitro but in patterns distinct from ERAP11

    OpenAIRE

    Georgiadou, Dimitra; Hearn, Arron; Evnouchidou, Irini; Chroni, Angeliki; Leondiadis, Leondios; Ian A York; Rock, Kenneth L.; Stratikos, Efstratios

    2010-01-01

    All three members of the oxytocinase sub-family of M1 aminopeptidases, ERAP1 (ERAAP), ERAP2 and PLAP (IRAP), have been implicated in the generation of MHC class I-presented peptides. ERAP1 and 2 trim peptides in the endoplasmic reticulum for direct presentation whereas PLAP has been recently implicated in cross presentation. The best characterized member of the family, ERAP1, has unique enzymatic properties that fit well with its role in antigen processing. ERAP1 can trim a large variety of l...

  16. Direct patterning of vortex generators on a fiber tip using a focused ion beam.

    Science.gov (United States)

    Vayalamkuzhi, Pramitha; Bhattacharya, Shanti; Eigenthaler, Ulrike; Keskinbora, Kahraman; Samlan, C T; Hirscher, Michael; Spatz, Joachim P; Viswanathan, Nirmal K

    2016-05-15

    The realization of spiral phase optical elements on the cleaved end of an optical fiber by focused ion beam milling is presented. A focused Ga+ ion beam with an acceleration voltage of 30 keV is used to etch continuous spiral phase plates and fork gratings directly on the tip of the fiber. The phase characteristics of the output beam generated by the fabricated structures measured via an interference experiment confirmed the presence of phase singularity in the output beam. The devices are expected to be promising candidates for all-fiber beam shaping and optical trapping applications. PMID:27176945

  17. Broad and ultra-flattened supercontinuum generation in the visible wavelengths based on the fundamental mode of photonic crystal fibre with central holes

    Institute of Scientific and Technical Information of China (English)

    Yuan Jin-Hui; Sang Xin-Zhu; Yu Chong-Xiu; Xin Xiang-Jun; Shen Xiang-Wei; Zhang Jin-Long; Zhou Gui-Yao; Li Shu-Guang; Hou Lan-Tian

    2011-01-01

    By coupling a train of femtosecond pulses with 100 fs pulse width at a repetition rate of 76 MHz generated by a mode-locked Ti: sapphire laser into the fundamental mode of photonic crystal fibre (PCF) with central holes fabricated through extracting air from the central hole, the broad and ultra-flattened supercontinuum (SC) in the visible wavelengths is generated. When the fundamental mode experiences an anomalous dispersion regime, three phases in the SC generation process are primarily presented. The SC generation (SCG) in the wavelength range from 470 nm to 805 nm does not emerge significant ripples due to a higher pump peak power and the corresponding mode fields at different wavelengths are observed using Bragg gratings. The relative intensity fluctuations of output spectrum in the wavelength ranges of 530 nm to 640 nm and 543 nm to 590 nm are only 0.028 and 0.0071, respectively.

  18. The Rh-1 Full-Size Humanoid Robot: Design, Walking Pattern Generation and Control

    Directory of Open Access Journals (Sweden)

    M. Arbulú

    2009-01-01

    Full Text Available This paper is an overview of the humanoid robot Rh-1, the second phase of the Rh project, which was launched by the Robotics Lab at the Carlos III University of Madrid in 2002. The robot mechanical design includes the specifications development in order to construct a platform, which is capable of stable biped walking. At first, the robots’ weights were calculated in order to obtain the inverse dynamics and to select the actuators. After that, mechanical specifications were introduced in order to verify the robot’s structural behaviour with different experimental gaits. In addition, an important aspect is the joints design when their axes are crossed, which is called ‘Joints of Rectangular Axes’ (JRA. The problem with these joints is obtaining two or more degrees of freedom (DOF in small space. The construction of a humanoid robot also includes the design of hardware and software architectures. The main advantage of the proposed hardware and software architectures is the use of standardised solutions frequently used in the automation industry and commercially available hardware components. It provides scalability, modularity and application of standardised interfaces and brings the design of the complex control system of the humanoid robot out of a closed laboratory to industry. Stable walking is the most essential ability for the humanoid robot. The three dimensional Linear Inverted Pendulum Model (3D-LIPM and the Cart-table models had been used in order to achieve natural and dynamic biped walking. Humanoid dynamics is widely simplified by concentrating its mass in the centre of gravity (COG and moving it following the natural inverted pendulum laws (3D-LIPM or by controlling the cart motion (Cart-table model. An offline-calculated motion pattern does not guarantee the walking stability of the humanoid robot. Control architecture for the dynamic humanoid robot walking was developed, which is able to make online modifications of the

  19. Practical performance and enabling technologies in immersion scanners for the double patterning generation

    Science.gov (United States)

    Ishikawa, Jun; Kohno, Hirotaka; Sato, Shinji; Kosugi, Junichi; Shibazaki, Yuichi

    2011-04-01

    At SPIE2010, excellent performance of the cutting edge immersion lithography scanner, the NSR-S620D, which is based on the new "Streamlign" platform was demonstrated. Last year's work focused mainly on machine evaluation data[1]. Now, many S620Ds are employed at customers' sites and being used in device manufacturing. In this paper, the authors will introduce the latest factory data, as well as various techniques that enable superior yield and enhance productivity in IC manufacturing. It is well understood, that in order to achieve further device shrinks without using traditional techniques such as NA expansion or wavelength reduction, several practical issues must be overcome. Extremely tight overlay performance will be required for pitch splitting double patterning, for example. In addition, it is also necessary to control the image plane and the aberration of the optics much more carefully. Of course these improvements must also be achieved with sufficient productivity (throughput). In order to satisfy all of the requirements for mass production at customer factories, many variable factors must be dealt with. One of these variable factors is the characteristics of the processed wafers that include on-flatness, grid distortion, steep topology around the edge, or topography of the previous layers' patterns. These factors typically impact overlay and/or auto focus accuracy. Another variable is the difference in exposure conditions between layers, which include illumination conditions, dose, reticle transmittance, and the alignment marks. Exposure induced heating in particular is the key issue for today's enhanced throughput capabilities, with regards to achieving both optimal accuracy and productivity. In some IC production facilities, and often foundries, many different kinds of products are manufactured in parallel. However, in order to enhance performance and accuracy, it is sometimes necessary to optimize machine parameters for each product. Cleary this

  20. Determine movement patterns and survival rates of Central Valley Chinook salmon, steelhead and their predators using acoustic tags.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project’s objective is to document movement patterns and survival rates of Chinook salmon, steelhead, green sturgeon, and other fish from several sources in...

  1. Neural control of locomotion : sensory control of the central pattern generator and its relation to treadmill training

    NARCIS (Netherlands)

    Van de Crommert, HWAA; Mulder, T; Duysens, J

    1998-01-01

    Many studies have shown that a special treadmill training is effective in restoring locomotor function in cats with a complete spinal lesion. In the last few years it has become possible to regain some locomotor activity in patients suffering from a spinal cord injury through an intense training on

  2. A novel approach to locomotion learning: Actor-Critic architecture using central pattern generators and dynamic motor primitives

    OpenAIRE

    Cai eLi; Robert eLowe; Tom eZiemke

    2014-01-01

    In this article, we propose an architecture of a bio-inspired controller that addresses the problem of learning different locomotion gaits for different robot morphologies. The modelling objective is split into two: baseline motion modelling and dynamics adaptation. Baseline motion modelling aims to achieve fundamental functions of a certain type of locomotion and dynamics adaptation provides a ``reshaping function for adapting the baseline motion to desired motion. Based on this assumption, ...

  3. Large-scale Generation of Patterned Bubble Arrays on Printed Bi-functional Boiling Surfaces

    Science.gov (United States)

    Choi, Chang-Ho; David, Michele; Gao, Zhongwei; Chang, Alvin; Allen, Marshall; Wang, Hailei; Chang, Chih-Hung

    2016-04-01

    Bubble nucleation control, growth and departure dynamics is important in understanding boiling phenomena and enhancing nucleate boiling heat transfer performance. We report a novel bi-functional heterogeneous surface structure that is capable of tuning bubble nucleation, growth and departure dynamics. For the fabrication of the surface, hydrophobic polymer dot arrays are first printed on a substrate, followed by hydrophilic ZnO nanostructure deposition via microreactor-assisted nanomaterial deposition (MAND) processing. Wettability contrast between the hydrophobic polymer dot arrays and aqueous ZnO solution allows for the fabrication of heterogeneous surfaces with distinct wettability regions. Heterogeneous surfaces with various configurations were fabricated and their bubble dynamics were examined at elevated heat flux, revealing various nucleate boiling phenomena. In particular, aligned and patterned bubbles with a tunable departure frequency and diameter were demonstrated in a boiling experiment for the first time. Taking advantage of our fabrication method, a 6 inch wafer size heterogeneous surface was prepared. Pool boiling experiments were also performed to demonstrate a heat flux enhancement up to 3X at the same surface superheat using bi-functional surfaces, compared to a bare stainless steel surface.

  4. Control Theoretic Modeling and Generated Flow Patterns of a Fish-Tail Robot

    Science.gov (United States)

    Massey, Brian; Morgansen, Kristi; Dabiri, Dana

    2003-11-01

    Many real-world engineering problems involve understanding and manipulating fluid flows. One of the challenges to further progress in the area of active flow control is the lack of appropriate models that are amenable to control-theoretic studies and algorithm design and also incorporate reasonably realistic fluid dynamic effects. We focus here on modeling and model-verification of bio-inspired actuators (fish-fin type structures) used to control fluid dynamic artifacts that will affect speed, agility, and stealth of Underwater Autonomous Vehicles (UAVs). Vehicles using fish-tail type systems are more maneuverable, can turn in much shorter and more constrained spaces, have lower drag, are quieter and potentially more efficient than those using propellers. We will present control-theoretic models for a simple prototype coupled fluid and mechanical actuator where fluid effects are crudely modeled by assuming only lift, drag, and added mass, while neglecting boundary effects. These models will be tested with different control input parameters on an experimental fish-tail robot with the resulting flow captured with DPIV. Relations between the model, the control function choices, the obtained thrust and drag, and the corresponding flow patterns will be presented and discussed.

  5. Interference patterns in the Spacelab 2 plasma wave data - Oblique electrostatic waves generated by the electron beam

    Science.gov (United States)

    Feng, Wei; Gurnett, Donald A.; Cairns, Iver H.

    1992-01-01

    During the Spacelab 2 mission the University of Iowa's Plasma Diagnostics Package (PDP) explored the plasma environment around the shuttle. Wideband spectrograms of plasma waves were obtained from the PDP at frequencies of 0-30 kHz and at distances up to 400 m from the shuttle. Strong low-frequency (below 10 kHz) electric field noise was observed in the wideband data during two periods in which an electron beam was ejected from the shuttle. This noise shows clear evidence of interference patterns caused by the finite (3.89 m) antenna length. The low-frequency noise was the most dominant type of noise produced by the ejected electron beam. Analysis of antenna interference patterns generated by these waves permits a determination of the wavelength, the direction of propagation, and the location of the source region. The observed waves have a linear dispersion relation very similar to that of ion acoustic waves. The waves are believed to be oblique ion acoustic or high-order ion cyclotron waves generated by a current of ambient electrons returning to the shuttle in response to the ejected electron beam.

  6. A Rich Morphological Diversity of Biosaline Drying Patterns Is Generated by Different Bacterial Species, Different Salts and Concentrations: Astrobiological Implications

    Science.gov (United States)

    Gómez Gómez, José María; Medina, Jesús; Rull, Fernando

    2016-07-01

    Biosaline formations (BSFs) are complex self-organized biomineral patterns formed by "hibernating" bacteria as the biofilm that contains them dries out. They were initially described in drying biofilms of Escherichia coli cells + NaCl. Due to their intricate 3-D morphology and anhydrobiosis, these biomineralogical structures are of great interest in astrobiology. Here we report experimental data obtained with various alkali halide salts (NaF, NaCl, NaBr, LiCl, KCl, CsCl) on BSF formation with E. coli and Bacillus subtilis bacteria at two saline concentrations: 9 and 18 mg/mL. Our results indicate that, except for LiCl, which is inactive, all the salts assayed are active during BSF formation and capable of promoting the generation of distinctive drying patterns at each salt concentration. Remarkably, the BSFs produced by these two bacterial species produce characteristic architectural hallmarks as the BSF dries. The potential biogenicity of these biosaline drying patterns is studied, and the astrobiological implications of these findings are discussed.

  7. Generation of three-dimensional patterns through wave interaction in a model of free surface swirling flow

    International Nuclear Information System (INIS)

    The free surface flow in a cylindrical tank over a rotating bottom is known to support spectacular three-dimensional patterns, including deformation of the inner free surface into the shape of rotating polygons and sloshing behavior of the upper free surface (e.g. Iga et al 2014 Fluid Dyn. Res. 46 031409). Through a stability analysis of a simplified model of this flow, we show that such patterns can be explained as a resonance mechanism involving different families of waves. The approach extends a previous work (Tophøj et al 2013 Phys. Rev. Lett. 110 194502) which explained the rotating polygons as an interaction between gravity waves and centrifugal waves, under the assumption that the base flow can be modeled as a potential vortex. We show that this previous model is justified for strong rotation rates (Dry-Potential case), and that for weaker rotations it can be improved by introducing an inner vortex core in solid-body rotation, which either extends to the center of the plate (Wet case) or surrounds a dry central region (Dry-Composite case). The study of this improved model predicts two new kinds of instabilities. The first occurs at low rotations (Wet case) and results from an interaction between gravity waves and the Kelvin–Kirchhoff wave (namely, oscillation of the boundary of the vortex core). This instability is proposed to be at the origin of the sloshing phenomenon. The second new instability occurs, for moderate rotations, (Dry-Composite case) as an interaction between gravity waves and a ‘Kelvin-Centrifugal’ wave characterized by deformation of the inner surface and the vortex core boundary in opposite directions. This instability exists for all azimuthal wave numbers starting from m = 1, this case corresponding to a ‘monogon’ pattern. (paper)

  8. Resolution Improvement and Pattern Generator Development for theMaskless Micro-Ion-Beam Reduction Lithography System

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ximan [Univ. of California, Berkeley, CA (United States)

    2006-05-18

    strategies have been studied. The dependence of the throughput with the exposure field size and the speed of the mechanical stage has been investigated. In order to perform maskless lithography, different micro-fabricated pattern generators have been developed for the MMRL system. Ion beamlet switching has been successfully demonstrated on the MMRL system. A positive bias voltage around 10 volts is sufficient to switch off the ion current on the micro-fabricated pattern generators. Some unexpected problems, such as the high-energy secondary electron radiations, have been discovered during the experimental investigation. Thermal and structural analysis indicates that the aperture displacement error induced by thermal expansion can satisfy the 3δ CD requirement for lithography nodes down to 25 nm. The cross-talking effect near the surface and inside the apertures of the pattern generator has been simulated in a 3-D ray-tracing code. New pattern generator design has been proposed to reduce the cross-talking effect. In order to eliminate the surface charging effect caused by the secondary electrons, a new beam-switching scheme in which the switching electrodes are immersed in the plasma has been demonstrated on a mechanically fabricated pattern generator.

  9. Internalization of externalities in the generation costs of electric power centrals of carbon, combined cycle and nuclear; Internalizacion de externalidades en los costos de generacion de centrales electricas de carbon, ciclo combinado y nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Gomez R, M.C. [Universidad Anahuac del Norte (Mexico); Palacios H, J.; Ramirez S, R.; Alonso V, G. [ININ, Carretera Mexico-Toluca Km. 36.5 Ocoyoacac 52750 Edo. de Mexico (Mexico)]. e-mail: fgrivera@avantel.net

    2007-07-01

    The technologies of electric power generation that use fossil fuels, they incorporate in the Even Total Cost of Generation (CTNG) only the direct costs of generation (investment, fuel costs, operation costs and maintenance). nevertheless, the nuclear energy incorporates besides the direct costs, the externalities that causes to the human health and the environment. In this work the CTNG is calculated that incorporates the externalities, of a thermoelectric power station of coal, a plant of combined cycle and of four reactors of Generation III (ABWR, ACR, AP1000 and EPR). The obtained results show that the nuclear power station has smaller CTNG that the technologies that use fossil fuels. It is important to stand out that they are only considering the externalities of the stage of electricity generation, for what the mining phase and transport of the fuel toward the central are not considered in the present document. (Author)

  10. Flow patterns generated by vibrations in weightlessness in binary mixture with Soret effect.

    Science.gov (United States)

    Shevtsova, Valentina; Melnikov, Denis; Gaponenko, Yuri; Lyubimova, Tatyana; Mialdun, Aliaksandr; Sechenyh, Vitaliy

    2012-07-01

    Vibrational convection refers to the specific flows that appear when a fluid with density gradient is subjected to external vibration. The density gradient may result from the inhomogeneity of temperature or composition. The study of vibrational impact on fluids has fundamental and applied importance. In weightlessness, vibrational convection is an additional way of transporting heat and matter similar to thermo- and solutocapillary convection. The response of the fluid to external forcing depends on the frequency of vibration. The case of small amplitude and high frequency vibration (when the period is much smaller than the characteristic viscous and heat (mass) diffusion times) is of special interest. In this case, the mean flow can be observed in the system, which describes the non-linear response of the fluid to a periodic excitation. The mean flow is most pronounced in the absence of other external forces (in particular, absence of static gravity). The experiment IVIDIL (Influence of Vibration on Diffusion in Liquids) has been conducted on the ISS during more than 3 months in 2009-2010. In the experimental liquids the density changes due to both the temperature and composition. 55 experimental runs of IVIDIL provided rich variety of valuable information about behavior of the liquid in weightlessness which is released with time, [1-3]. The current results provide experimental and numerical evidence of richness of flow patterns and their classification. References: 1. Shevtsova V., Mialdun A., Melnikov D., Ryzhkov I., Gaponenko Y., Saghir Z., Lyubimova T., Legros J.C., IVIDIL experiment onboard ISS: thermodiffusion in presence of controlled vibrations, Comptes Rendus Mecanique, 2011, 339, 310-317 2. Shevtsova V., Lyubimova T., Saghir Z. , Melnikov D., Gaponenko Y. , Sechenyh V. , Legros J.C. , Mialdun A., IVIDIL: on-board g-jitters and diffusion controlled phenomena; Journal of Physics: Conference Series, 2011, 327, 012031 3. Mazzoni S., Shevtsova V., Mialdun A

  11. On the processes generating latitudinal richness gradients: identifying diagnostic patterns and predictions

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbert, Allen H.; Stegen, James C.

    2014-12-02

    Many processes have been put forward to explain the latitudinal gradient in species richness. Here, we use a simulation model to examine four of the most common hypotheses and identify patterns that might be diagnostic of those four hypotheses. The hypotheses examined include (1) tropical niche conservatism, or the idea that the tropics are more diverse because a tropical clade origin has allowed more time for diversification in the tropics and has resulted in few species adapted to extra-tropical climates. (2) The productivity, or energetic constraints, hypothesis suggests that species richness is limited by the amount of biologically available energy in a region. (3) The tropical stability hypothesis argues that major climatic fluctuations and glacial cycles in extratropical regions have led to greater extinction rates and less opportunity for specialization relative to the tropics. (4) Finally, the speciation rates hypothesis suggests that the latitudinal richness gradient arises from a parallel gradient in rates of speciation. We found that tropical niche conservatism can be distinguished from the other three scenarios by phylogenies which are more balanced than expected, no relationship between mean root distance and richness across regions, and a homogeneous rate of speciation across clades and through time. The energy gradient, speciation gradient, and disturbance gradient scenarios all exhibited phylogenies which were more imbalanced than expected, showed a negative relationship between mean root distance and richness, and diversity-dependence of speciation rate estimates through time. Using Bayesian Analysis of Macroevolutionary Mixtures on the simulated phylogenies, we found that the relationship between speciation rates and latitude could distinguish among these three scenarios. We emphasize the importance of considering multiple hypotheses and focusing on diagnostic predictions instead of predictions that are consistent with more than one hypothesis.

  12. Large-scale patterns of Quercus ilex, Quercus suber, and Quercus pyrenaica regeneration in central-western Spain

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Rolo, Víctor; Moreno, Gerardo

    2010-01-01

    In Central-Western Spain, forests and woodlands composed of Quercus sp. support outstanding levels of biodiversity, but there is increasing concern about their long-term persistence due to a lack of regeneration. We hypothesize that this regenerative lack is operating on a large geographic scale;...

  13. Spatial pattern and temporal variability of runoff processes in Mediterranean Mountain environments - a case study of the Central Spanish Pyrenees

    NARCIS (Netherlands)

    Butzen, V.; Seeger, K.M.; Casper, M.C.

    2011-01-01

    Mediterranean mountain environments like the Central Spanish Pyrenees show a highly variable rainfall-runoff response, mainly explained by the intense intra- and inter-annual variability of precipitation yield. This leads to a highly differentiated moisture status and therefore it is assumed to lead

  14. Use of soil moisture dynamics and patterns for the investigation of runoff generation processes with emphasis on preferential flow

    Directory of Open Access Journals (Sweden)

    T. Blume

    2007-08-01

    Full Text Available Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale and indicator maps (for the long-term and hillslope scale. Annual dynamics of soil moisture and decimeter-scale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a data-scarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to self

  15. Unveiling distribution patterns of freshwater phytoplankton by a next generation sequencing based approach.

    Directory of Open Access Journals (Sweden)

    Alexander Eiler

    Full Text Available The recognition and discrimination of phytoplankton species is one of the foundations of freshwater biodiversity research and environmental monitoring. This step is frequently a bottleneck in the analytical chain from sampling to data analysis and subsequent environmental status evaluation. Here we present phytoplankton diversity data from 49 lakes including three seasonal surveys assessed by next generation sequencing (NGS of 16S ribosomal RNA chloroplast and cyanobacterial gene amplicons and also compare part of these datasets with identification based on morphology. Direct comparison of NGS to microscopic data from three time-series showed that NGS was able to capture the seasonality in phytoplankton succession as observed by microscopy. Still, the PCR-based approach was only semi-quantitative, and detailed NGS and microscopy taxa lists had only low taxonomic correspondence. This is probably due to, both, methodological constraints and current discrepancies in taxonomic frameworks. Discrepancies included Euglenophyta and Heterokonta that were scarce in the NGS but frequently detected by microscopy and Cyanobacteria that were in general more abundant and classified with high resolution by NGS. A deep-branching taxonomically unclassified cluster was frequently detected by NGS but could not be linked to any group identified by microscopy. NGS derived phytoplankton composition differed significantly among lakes with different trophic status, showing that our approach can resolve phytoplankton communities at a level relevant for ecosystem management. The high reproducibility and potential for standardization and parallelization makes our NGS approach an excellent candidate for simultaneous monitoring of prokaryotic and eukaryotic phytoplankton in inland waters.

  16. Investigating Theoretical PV Energy Generation Patterns with Their Relation to the Power Load Curve in Poland

    Directory of Open Access Journals (Sweden)

    Jakub Jurasz

    2016-01-01

    Full Text Available Polish energy sector is (almost from its origin dominated by fossil fuel feed power. This situation results from an abundance of relatively cheap coal (hard and lignite. Brown coal due to its nature is the cheapest energy source in Poland. However, hard coal which fuels 60% of polish power plants is picking up on prices and is susceptible to the coal imported from neighboring countries. Forced by the European Union (EU regulations, Poland is struggling at achieving its goal of reaching 15% of energy consumption from renewable energy sources (RES by 2020. Over the year 2015, RES covered 11.3% of gross energy consumption but this generation was dominated by solid biomass (over 80%. The aim of this paper was to answer the following research questions: What is the relation of irradiation values to the power load on a yearly and daily basis? and how should photovoltaics (PV be integrated in the polish power system? Conducted analysis allowed us to state that there exists a negative correlation between power demand and irradiation values on a yearly basis, but this is likely to change in the future. Secondly, on average, daily values of irradiation tend to follow power load curve over the first hours of the day.

  17. Linking Spatial Patterns of Groundwater Table Dynamics and Streamflow Generation Processes in a Small Developed Catchment

    Directory of Open Access Journals (Sweden)

    Natalie Orlowski

    2014-10-01

    Full Text Available Knowledge about water flow paths is essential for understanding biogeochemical fluxes in developed agricultural landscapes, i.e., the input of nutrients into surface waters, soil erosion, or pesticide fate. Several methods are available to study rainfall-runoff processes and flux partitioning: hydrometric based approaches, chemical tracers, modeling, and stable isotope applications. In this study a multi-method approach was conducted to gain insights into the hydrological fluxes and process understanding within the complex anthropogenic-influenced catchment of the Vollnkirchener Bach, Germany. Our results indicate that the catchment responds differently to precipitation input signals and dominant runoff-generation processes change throughout the year. Rainfall-induced runoff events during dry periods are characterized by a temporarily active combined sewer overflow. During stormflow, a large contribution of fast event water is observed. At low flow conditions losing and gaining conditions occur in parallel. However, when catchment’s moisture conditions are high, an ephemeral source from clay shale-graywacke dominated forested sites becomes active. The study reveals that the collection of detailed distributed hydrometric data combined with isotopic tracers, provides fundamental information on the complex catchment behavior, which can finally be utilized for conceptualizing water fluxes at a small catchment scale.

  18. Post-fire overland flow generation and inter-rill erosion under simulated rainfall in two eucalypt stands in north-central Portugal.

    Science.gov (United States)

    Malvar, M C; Prats, S A; Nunes, J P; Keizer, J J

    2011-02-01

    The aim of this study was to improve the existing knowledge of the runoff and inter-rill erosion response of forest stands following wildfire, focusing on commercial eucalypt plantations and employing field rainfall simulation experiments (RSE's). Repeated RSE's were carried out in two adjacent but contrasting eucalypt stands on steep hill slopes in north-central Portugal that suffered a moderate severity fire in July 2005. This was done at six occasions ranging from 3 to 24 months after the fire and using a paired-plot experimental design that comprised two pairs of RSE's at each site and occasion. Of the 46 RSE's: (i) 24 and 22 RSE's involved application rates of 45-50 and 80-85 mm h(-1), respectively; (ii) 22 took place in a stand that had been ploughed in down slope direction several years before the wildfire and 24 in an unploughed stand. The results showed a clear tendency for extreme-intensity RSE's to produce higher runoff amounts and greater soil and organic matter losses than the simultaneous high-intensity RSE's on the neighbouring plots. However, there existed marked exceptions, both in space (for one of the plot pairs) and time (under intermediate soil water repellency conditions). Also, overland flow generation and erosion varied significantly between the various field campaigns. This temporal pattern markedly differed from a straightforward decline with time-after-fire and rather suggested a seasonal component, reflecting broad variations in topsoil water repellency. The ploughed site produced less runoff and erosion than the unploughed site, contrary to what would be expected if the down slope ploughing had occurred after the wildfire instead of several years before it. Finally, sediment losses at both study sites were noticeably lower than those reported by other studies involving repeat RSE's, i.e. in Australia and western Spain. This possibly reflected a history of intensive land use in the study region, including in more recent times after the

  19. Regional patterns in current and future export production in the central Arctic Ocean quantified from nitrate fluxes

    Science.gov (United States)

    Randelhoff, Achim; Guthrie, John D.

    2016-08-01

    Due to severe nutrient and light limitation, the central Arctic Ocean has been characterized as a region of low primary productivity, with high retention of carbon in the surface waters. Using an in-depth analysis of published and new measurements of turbulent microstructure and high-resolution profiles of nitrate concentration, we reassess the vertical supply of nitrate to the Polar Mixed Layer and the associated export of particulate organic matter across the nitracline. We estimate annual export production to be approximately 1.5-3 g C m-2, but regional differences in both current and future potential of export production are large, with the eastern Arctic being least constrained by vertical nutrient supply and the western Arctic the most. Future changes in export production are assessed using a 1-D budget model; increases in the Atlantic sector are possibly compensated by decreases in the rest of the central Arctic Ocean such that the net change might be insignificant.

  20. Temporal patterns in Saturnidae (silk moth) and Sphingidae (hawk moth) assemblages in protected forests of central Uganda.

    Science.gov (United States)

    Akite, Perpetra; Telford, Richard J; Waring, Paul; Akol, Anne M; Vandvik, Vigdis

    2015-04-01

    Forest-dependent biodiversity is threatened throughout the tropics by habitat loss and land-use intensification of the matrix habitats. We resampled historic data on two moth families, known to play central roles in many ecosystem processes, to evaluate temporal changes in species richness and community structure in three protected forests in central Uganda in a rapidly changing matrix. Our results show some significant declines in the moth species richness and the relative abundance and richness of forest-dependent species over the last 20-40 years. The observed changes in species richness and composition among different forests, ecological types, and moth groups highlight the need to repeatedly monitor biodiversity even within protected and relatively intact forests. PMID:25937916

  1. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching.

    Science.gov (United States)

    Someswara Rao, Chinta; Raju, S Viswanadha

    2016-03-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats) in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching.

  2. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching

    Science.gov (United States)

    Someswara Rao, Chinta; Raju, S. Viswanadha

    2016-01-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats) in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching. PMID:26981434

  3. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching.

    Science.gov (United States)

    Someswara Rao, Chinta; Raju, S Viswanadha

    2016-03-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macaca mulatta, Nomascus leucogenys, Pan troglodytes, Papio anubis and Pongo abelii genome data sets for all those locis. We find the successive occurence frequency for all the above 10 SSR (simple sequence repeats) in the above genome data sets on a chromosome-by-chromosome basis with multiple pattern 2° shaft multicore string matching. PMID:26981434

  4. NON-NEUTRALIZED ELECTRIC CURRENT PATTERNS IN SOLAR ACTIVE REGIONS: ORIGIN OF THE SHEAR-GENERATING LORENTZ FORCE

    Energy Technology Data Exchange (ETDEWEB)

    Georgoulis, Manolis K. [Research Center for Astronomy and Applied Mathematics of the Academy of Athens, 4 Soranou Efesiou Street, Athens GR-11527 (Greece); Titov, Viacheslav S.; Mikic, Zoran [Predictive Science, Inc., 9990 Mesa Rim Road, San Diego, CA 92121 (United States)

    2012-12-10

    Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within ARs are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most ARs appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated ARs remain globally current-balanced. In addition, we confirm and quantify the preference of a given magnetic polarity to follow a given sense of electric currents, indicating a dominant sense of twist in ARs. This coherence effect is more pronounced in more compact ARs with stronger PILs and must be of sub-photospheric origin. Our results yield a natural explanation of the Lorentz force, invariably generating velocity and magnetic shear along strong PILs, thus setting a physical context for the observed pre-eruption evolution in solar ARs.

  5. Congruent phylogeographical patterns of eight tree species in Atlantic Central Africa provide insights into the past dynamics of forest cover

    OpenAIRE

    Dauby, G.; Duminil, J.; Heuertz, Miryam; Koffi, G. K.; T. Stévart; Olivier J Hardy

    2014-01-01

    Cycles of Quaternary climatic change are assumed to be major drivers of African rainforest dynamics and evolution. However, most hypotheses on past vegetation dynamics relied on palaeobotanical records, an approach lacking spatial resolution, and on current patterns of species diversity and endemism, an approach confounding history and environmental determinism. In this context, a comparative phylogeographical study of rainforest species represents a complementary approach because Pleistocene...

  6. Environmental controls on spatial patterns in the long-term persistence of giant kelp in central California

    Science.gov (United States)

    Young, Mary Alida; Cavanaugh, Kyle C.; Bell, Tom W.; Raimondi, Peter T.; Edwards, Christopher A.; Drake, Patrick T.; Erikson, Li H.; Storlazzi, Curt

    2016-01-01

    As marine management is moving towards the practice of protecting static areas, it is 44 important to make sure protected areas capture and protect persistent populations. Rocky reefs in 45 many temperate areas worldwide serve as habitat for canopy forming macroalgae and these 46 structure forming species of kelps (order Laminariales) often serve as important habitat for a great 47 diversity of species. Macrocystis pyrifera is the most common canopy forming kelp species found 48 along the coast of California but the distribution and abundance of M. pyrifera varies in space and 49 time. The purpose of this study is to determine what environmental parameters are correlated with 50 the spatial and temporal persistence of M. pyrifera along the central coast of California and how 51 well those environmental parameters can be used to predict areas where M. pyrifera is more likely 52 to persist. Nine environmental variables considered in this study included depth of the seafloor, 53 structure of the rocky reef, proportion of rocky reef, size of kelp patch, biomass of kelp within a 54 patch, distance from the edge of a kelp patch, sea surface temperature, wave orbital velocities, and 55 population connectivity of individual kelp patches. Using a generalized linear mixed effects model 56 (GLMM), the persistence of M. pyrifera was significantly associated with seven of the nine 57 variables considered: depth, complexity of the rocky reef, proportion of rock, patch biomass, 58 distance from the edge of a patch, population connectivity, and wave-orbital velocities. These 59 seven environmental variables were then used to predict the persistence of kelp across the central 60 coast and these predictions were compared to a reserved dataset of M. pyrifera persistence, which 61 was not used in the creation of the GLMM. The environmental variables were shown to accurately 62 predict the persistence of M. pyrifera within the central coast of California (r = 0.71, Pmanagement of these

  7. Investigation of vortex clouds and droplet sizes in heated water spray patterns generated by axisymmetric full cone nozzles.

    Science.gov (United States)

    Naz, M Y; Sulaiman, S A; Ariwahjoedi, B; Ku Shaari, Ku Zilati

    2013-01-01

    The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size distribution under varying temperature and load pressure. Using a high speed camera, the spray patterns generated by axisymmetric full cone nozzles were visualized as a function water temperature and load pressure. The image analysis confirmed that the spray cone angle and width do not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The formation and decay of semitorus like vortex clouds were also noticed in spray structures generated at near water boiling point temperature. For the nozzle with smallest orifice diameter (1.19 mm), these vortex clouds were very clear at 90°C heating temperature and 1 bar water load pressure. In addition, the sauter mean diameter (SMD) of the spray droplets was also measured by using Phase Doppler Anemometry (PDA) at different locations downstream of the nozzle exit. It was noticed that SMD varies slightly w.r.t. position when measured at room temperature whereas at higher temperature values, it became almost constant at distance of 55 mm downstream of the nozzle exit. PMID:24307881

  8. Investigation of Vortex Clouds and Droplet Sizes in Heated Water Spray Patterns Generated by Axisymmetric Full Cone Nozzles

    Directory of Open Access Journals (Sweden)

    M. Y. Naz

    2013-01-01

    Full Text Available The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size distribution under varying temperature and load pressure. Using a high speed camera, the spray patterns generated by axisymmetric full cone nozzles were visualized as a function water temperature and load pressure. The image analysis confirmed that the spray cone angle and width do not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The formation and decay of semitorus like vortex clouds were also noticed in spray structures generated at near water boiling point temperature. For the nozzle with smallest orifice diameter (1.19 mm, these vortex clouds were very clear at 90°C heating temperature and 1 bar water load pressure. In addition, the sauter mean diameter (SMD of the spray droplets was also measured by using Phase Doppler Anemometry (PDA at different locations downstream of the nozzle exit. It was noticed that SMD varies slightly w.r.t. position when measured at room temperature whereas at higher temperature values, it became almost constant at distance of 55 mm downstream of the nozzle exit.

  9. Investigation of Vortex Clouds and Droplet Sizes in Heated Water Spray Patterns Generated by Axisymmetric Full Cone Nozzles

    Science.gov (United States)

    Naz, M. Y.; Sulaiman, S. A.; Ariwahjoedi, B.; Ku Shaari, Ku Zilati

    2013-01-01

    The hot water sprays are an important part of many industrial processes, where the detailed knowledge of physical phenomena involved in jet transportation, interaction, secondary breakup, evaporation, and coalescence of droplets is important to reach more efficient processes. The objective of the work was to study the water spray jet breakup dynamics, vortex cloud formation, and droplet size distribution under varying temperature and load pressure. Using a high speed camera, the spray patterns generated by axisymmetric full cone nozzles were visualized as a function water temperature and load pressure. The image analysis confirmed that the spray cone angle and width do not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The formation and decay of semitorus like vortex clouds were also noticed in spray structures generated at near water boiling point temperature. For the nozzle with smallest orifice diameter (1.19 mm), these vortex clouds were very clear at 90°C heating temperature and 1 bar water load pressure. In addition, the sauter mean diameter (SMD) of the spray droplets was also measured by using Phase Doppler Anemometry (PDA) at different locations downstream of the nozzle exit. It was noticed that SMD varies slightly w.r.t. position when measured at room temperature whereas at higher temperature values, it became almost constant at distance of 55 mm downstream of the nozzle exit. PMID:24307881

  10. Microbial infection and antibiotic patterns among intensive care unit patients in a tertiary hospital in Central Nepal

    Directory of Open Access Journals (Sweden)

    RK Sanjana

    2013-09-01

    Full Text Available Aims The present study is a fundamental effort to evaluate the bacteriological and antibiotic patterns in the Intensive Care Unit (ICU setting in a tertiary care hospital. This study was carried out to guide the clinician in choosing the appropriate antibiotics and to prevent emergence of multidrug resistance bacteria. Materials and Methods Between March 2009 to Feb 2012, the samples from various ICUs that were submitted to the microbiology laboratory for culture and sensitivity were included in this study. All the organisms were identified morphologically and biochemically by standard laboratory procedure and antibiotic susceptibility pattern was determined by disc diffusion methods. Result Of 3,780 specimens, 2,312 (61.1% isolates were recovered. Single organisms were isolated from 1,746 (75.5% samples while the remaining 566 (24.4% had two or more organisms isolated. Pseudomonas aeruginosa was the most common isolate 819 (35.4%, followed by Klebsiella pneumoniae 637 (27.5%. Antibiotics sensitivity of Pseudomonas aeruginosa showed that almost all isolates were resistant to cephalexin (97.8% and ciprofloxacin (80.3%. However (95.8% of the isolates were sensitive to tobramycin, (92.0% to meropenem & (74.80 % to amikacin. Conclusion It is concluded that Pseudomonas aeruginosa is the predominate pathogen isolated from ICUs of this Hospital. Most of the frequently isolated pathogens are resistant to cephalosporins and quinolone antibiotics as compared to aminoglycosides and carbapenem. Regular surveillance of antibiotic susceptibility pattern is very important for setting a guideline to the clinician in choosing an appropriate therapy of infected patients of ICUs. Journal of College of Medical Sciences-Nepal, 2012, Vol-8, No-3, 1-8 DOI: http://dx.doi.org/10.3126/jcmsn.v8i3.8678

  11. Changes in Central European Soil Moisture Availability and Atmospheric Circulation Patterns between 1875 and 2005 - Regional Climate Change in Progress?

    Science.gov (United States)

    Trnka, M.; Kysely, J.; Dubrovsky, M.; Mozny, M.; Hostynek, J.; Svoboda, M.; Hayes, M. J.; Zalud, Z.

    2007-12-01

    Relationships between the soil moisture availability and the atmospheric circulation in Central Europe were analyzed for the period 1881-2005. The analysis was based on the Hess-Brezowsky catalogue of circulation types (CTs), and a series of weekly self-calibrated Palmer Z-index (scZ-index) and Palmer Drought Severity Index (scPDSI) values at seven stations where high-quality daily data has recently become available. The results show that the large-scale droughts during spring months (MAM) were associated with east (E), south (S), and south- east (SE) circulation types, whereas during summer (JJA) and the whole vegetation season, i.e., April-September (VEG), the Central Europe high pressure systems (HM) and east (E) circulation types were conducive to drought. Statistically significant drying trends were noted at a majority of the stations, especially during MAM and JJA, over the whole period for which the scPDSI and scZ-index series were available (1875-2005). Although almost no statistically significant tendencies were found prior to 1940, a significant tendency towards more intense drought was present at all sites after this year. The largest drying trend was noted during the VEG and AMJ seasons. The overall drying trend might be associated with shifts in the frequency of CTs, especially during AMJ. Although the aggregate frequency of occurrence of drought-conducive CTs (i.e. E, S and HM) remained stable at approximately 30% up to the 1940s, a steady increase to the present 55% frequency is observed afterwards. Higher frequencies of S and HM types drove the observed increase of drought-conducive CTs at the expense of N types that are associated with wet conditions. The long-term shifts in the frequency of circulation types conducive to drought explain more than 50% of the long-term variations of both scZ-index and PDSI values over the territory of the Czech Republic, and they are likely to affect whole central European region as well. Acknowledgement: This study

  12. Patterns of central venous oxygen saturation, lactate and veno-arterial CO 2 difference in patients with septic shock

    Directory of Open Access Journals (Sweden)

    Rubina Khullar Mahajan

    2015-01-01

    Full Text Available Background and Aims: Tissue hypoperfusion is reflected by metabolic parameters such as lactate, central venous oxygen saturation (ScvO 2 and the veno-arterial CO 2 (vaCO 2 difference. We studied the relation of these parameters over time and with outcome in patients with severe septic shock. Materials and Methods: In this single-center, prospective observational cohort study, adult patients (≥18 years with circulatory shock were included. Echocardiography and simultaneous arterial and venous blood gases were done on enrolment (0 h and at 24, 48 and 72 h. The partial pressure of CO 2 , lactate and ScvO 2 were recorded from the central venous blood samples. The vaCO 2 was calculated as the difference in CO 2 between paired venous and arterial blood gas samples. Results: Of the 104 patients with circulatory shock, 79 patients (44 males with septic shock aged 49.8 (standard deviation ± 14.6 years and with sequential organ failure assessment (SOFA score of 11.0 ± 3.4 were included. 71 patients (89.9% were ventilated (11.4 ± 12.3 ventilator-free days. The duration of hospitalization was 16.6 ± 12.8 days and hospital mortality 50.6%. Lactate significantly decreased over time with a greater decrement in survivors than nonsurvivors (−0.35 vs. −0.10, P 70% and not in ScvO 2 ≤70%. Conclusion: In septic shock, vaCO 2 ≤6 mmHg is independently associated with mortality, particularly in those with normalized ScvO 2 consistent with metabolic microcirculatory abnormalities in these patients.

  13. Pareto optimality between width of central lobe and peak sidelobe intensity in the far-field pattern of lossless phase-only filters for enhancement of transverse resolution.

    Science.gov (United States)

    Mukhopadhyay, Somparna; Hazra, Lakshminarayan

    2015-11-01

    Resolution capability of an optical imaging system can be enhanced by reducing the width of the central lobe of the point spread function. Attempts to achieve the same by pupil plane filtering give rise to a concomitant increase in sidelobe intensity. The mutual exclusivity between these two objectives may be considered as a multiobjective optimization problem that does not have a unique solution; rather, a class of trade-off solutions called Pareto optimal solutions may be generated. Pareto fronts in the synthesis of lossless phase-only pupil plane filters to achieve superresolution with prespecified lower limits for the Strehl ratio are explored by using the particle swarm optimization technique.

  14. Dengue virus in sub-tropical northern and central Viet Nam: population immunity and climate shape patterns of viral invasion and maintenance.

    Science.gov (United States)

    Rabaa, Maia A; Simmons, Cameron P; Fox, Annette; Le, Mai Quynh; Nguyen, Thuy Thi Thu; Le, Hai Yen; Gibbons, Robert V; Nguyen, Xuyen Thanh; Holmes, Edward C; Aaskov, John G

    2013-01-01

    Dengue virus transmission occurs in both epidemic and endemic cycles across tropical and sub-tropical regions of the world. Incidence is particularly high in much of Southeast Asia, where hyperendemic transmission plagues both urban and rural populations. However, endemicity has not been established in some areas with climates that may not support year-round viral transmission. An understanding of how dengue viruses (DENV) enter these environments and whether the viruses persist in inapparent local transmission cycles is central to understanding how dengue emerges in areas at the margins of endemic transmission. Dengue is highly endemic in tropical southern Vietnam, while increasingly large seasonal epidemics have occurred in northern Viet Nam over the last decade. We have investigated the spread of DENV-1 throughout Vietnam to determine the routes by which the virus enters northern and central regions of the country. Phylogeographic analysis of 1,765 envelope (E) gene sequences from Southeast Asia revealed frequent movement of DENV between neighboring human populations and strong local clustering of viral lineages. Long-distance migration of DENV between human population centers also occurred regularly and on short time-scales, indicating human-mediated viral invasion into northern Vietnam. Human populations in southern Vietnam were found to be the primary source of DENV circulating throughout the country, while central and northern Vietnam acted as sink populations, likely due to reduced connectedness to other populations in the case of the central regions and to the influence of temperature variability on DENV replication and vector survival and competence in the north. Finally, phylogeographic analyses suggested that viral movement follows a gravity model and indicates that population immunity and physical and economic connections between populations may play important roles in shaping patterns of DENV transmission.

  15. Dengue virus in sub-tropical northern and central Viet Nam: population immunity and climate shape patterns of viral invasion and maintenance.

    Directory of Open Access Journals (Sweden)

    Maia A Rabaa

    Full Text Available Dengue virus transmission occurs in both epidemic and endemic cycles across tropical and sub-tropical regions of the world. Incidence is particularly high in much of Southeast Asia, where hyperendemic transmission plagues both urban and rural populations. However, endemicity has not been established in some areas with climates that may not support year-round viral transmission. An understanding of how dengue viruses (DENV enter these environments and whether the viruses persist in inapparent local transmission cycles is central to understanding how dengue emerges in areas at the margins of endemic transmission. Dengue is highly endemic in tropical southern Vietnam, while increasingly large seasonal epidemics have occurred in northern Viet Nam over the last decade. We have investigated the spread of DENV-1 throughout Vietnam to determine the routes by which the virus enters northern and central regions of the country. Phylogeographic analysis of 1,765 envelope (E gene sequences from Southeast Asia revealed frequent movement of DENV between neighboring human populations and strong local clustering of viral lineages. Long-distance migration of DENV between human population centers also occurred regularly and on short time-scales, indicating human-mediated viral invasion into northern Vietnam. Human populations in southern Vietnam were found to be the primary source of DENV circulating throughout the country, while central and northern Vietnam acted as sink populations, likely due to reduced connectedness to other populations in the case of the central regions and to the influence of temperature variability on DENV replication and vector survival and competence in the north. Finally, phylogeographic analyses suggested that viral movement follows a gravity model and indicates that population immunity and physical and economic connections between populations may play important roles in shaping patterns of DENV transmission.

  16. Method of estimating the exposure of the natural environment to 50 Hz electric and magnetic fields in power systems with distributed and centralized generations

    Directory of Open Access Journals (Sweden)

    Zeńczak Michał

    2016-06-01

    Full Text Available The development of a distributed generation will influence the structure of the power transmission and distribution network. Distributed sources have lower power and therefore the lines of lower voltage are used. Therefore, the electric field intensity near such lines is lower. On the other hand magnetic field intensity may prove essential. The main aim of the paper is to present a method estimating the “ballast” of the natural environment at 50 Hz electric and magnetic fields in the power system, with distributed and centralized generation in real operating conditions.

  17. Contrasting Holocene environmental histories may explain patterns of species richness and rarity in a Central European landscape

    Science.gov (United States)

    Hájek, Michal; Dudová, Lydie; Hájková, Petra; Roleček, Jan; Moutelíková, Jitka; Jamrichová, Eva; Horsák, Michal

    2016-02-01

    The south-western part of the White Carpathians (Czech Republic, Slovakia) is known for its exceptional grassland diversity and occurrence of many species with disjunct distribution patterns, including isolated populations of continental forest-steppe species. The north-eastern part of the mountain range lacks many of these species and has clearly lower maxima of grassland species richness. While climatic and edaphic conditions of both regions largely overlap, their specific environmental history has been hypothesized to explain the exceptional richness in the south-western part. We explored an entire-Holocene record (9650 BC onwards), the first one from the north-eastern part, to find out whether differences in history may explain regional patterns of species rarity and richness. We analysed pollen, macrofossils and molluscs and dated the sequence with 13 radiocarbon dates. We further reconstructed past human activities using available archaeological evidence. Based on this analysis, the Early-Holocene landscape was reconstructed as semi-open with broad-leaved trees (elm and lime) appearing already around 9500 BC. Lime reached a relative abundance of as much as 60% around 8700 BC. All analysed proxies support the existence of dense lime-dominated woodland during the forest optimum starting after climate moistening around 6800 BC, some 2200 years before the first signs of slight forest opening in the Late Neolithic. During the Bronze and Iron Ages, human pressure increased, which led to a decrease in lime and an increase in oak, hornbeam, grasses and grassland snails; nevertheless, forests still dominated the landscape and beech spread when human impact temporarily decreased. Colonisation after AD 1350 created the modern grassland-rich landscape. All available evidence confirmed an early post-Glacial expansion of broad-leaved trees, supporting the hypothesis on their glacial refugia in the Carpathians, as well as presence of closed-canopy forest well before the

  18. The ArF laser for the next-generation multiple-patterning immersion lithography supporting green operations

    Science.gov (United States)

    Ishida, Keisuke; Ohta, Takeshi; Miyamoto, Hirotaka; Kumazaki, Takahito; Tsushima, Hiroaki; Kurosu, Akihiko; Matsunaga, Takashi; Mizoguchi, Hakaru

    2016-03-01

    Multiple patterning ArF immersion lithography has been expected as the promising technology to satisfy tighter leading edge device requirements. One of the most important features of the next generation lasers will be the ability to support green operations while further improving cost of ownership and performance. Especially, the dependence on rare gases, such as Neon and Helium, is becoming a critical issue for high volume manufacturing process. The new ArF excimer laser, GT64A has been developed to cope with the reduction of operational costs, the prevention against rare resource shortage and the improvement of device yield in multiple-patterning lithography. GT64A has advantages in efficiency and stability based on the field-proven injection-lock twin-chamber platform (GigaTwin platform). By the combination of GigaTwin platform and the advanced gas control algorithm, the consumption of rare gases such as Neon is reduced to a half. And newly designed Line Narrowing Module can realize completely Helium free operation. For the device yield improvement, spectral bandwidth stability is important to increase image contrast and contribute to the further reduction of CD variation. The new spectral bandwidth control algorithm and high response actuator has been developed to compensate the offset due to thermal change during the interval such as the period of wafer exchange operation. And REDeeM Cloud™, new monitoring system for managing light source performance and operations, is on-board and provides detailed light source information such as wavelength, energy, E95, etc.

  19. Comparison of Growth and Development Patterns of Fenneropenaeus chinensis (Osbeck) Huanghai No.1and the First Generation of Wild Population

    Institute of Scientific and Technical Information of China (English)

    Yuying HE; Ping LIU; Qingyin WANG; Jian LI; Zhaoxia LI

    2013-01-01

    [Objective] The aim was to estimate the developmental characteristics of Huanghai No.1 and the first generation of wild population in Fenneropenaeus chinensis for providing a reference for the development,feeding management and breeding.[Method] Four growth models were used to fit the growth patterns of 15 morphological traits.The squared multiple correlation coefficient (R2) of the Cubic growth model was higher than the other three models,so it was selected to investigate the growth pattern and age in month at inflexion.[Result] Ages in month at inflexion of body weight in Huanghai No.1 and the G1 population were 2.87 (body weight at inflexion was 14.98 g) and 4.05 (body weight at inflexion was 26.26 g),respectively.In addition,Ages in month at inflexion of morphological characters in Huanghai No.1 were from 0.51 to 3.07.CL had the most rapid growth rate,followed by AW,CH,AH,CW,BL,FL,AL5,AL3,AL4,TL,AL2,AL1,and AL6.Ages in month at inflexion in the G1 population were from 2.38 to 3.08,except that of AL2,and the order of achieving the most rapid growth rate was AL2,AL1,AL3,AL4,CH,AL5,CW,FL,AH,AW,TL,CL,BL,and AL6,that delayed one month than that of Huanghai No.1 except AL2 and AL1.[Conclusion] The development of Huanghai No.1 cultivar was advanced for about one month compared to that of the G1 population.

  20. Twenty Years of Elfin Enumeration: Abundance Patterns of Five Species of Callophrys (Lycaenidae) in Central Wisconsin, USA

    Science.gov (United States)

    Swengel, Ann B.; Swengel, Scott R.

    2014-01-01

    We recorded five species of elfins (Callophrys) during annual spring surveys targeting frosted elfin C. irus (state-listed as threatened) in 19 pine-oak barrens in central Wisconsin USA during 1994–2013. At the northwest end of its range here, C. irus co-varied with spring temperature, but declined significantly over time (eight sites verified extant of originally 17). Two other specialists increased significantly. The northern specialist, hoary elfin C. polios (nine sites), correlated positively with the previous year’s growing season precipitation. The southern specialist, Henry’s elfin C. henrici (11 sites), co-varied with winter precipitation and spring temperature and dryness. The two resident generalists had stable trends. For all species, the first observed date per year became earlier over time and varied more than the last observed date. Thus, flight period span increased with earlier first observed dates. Elfin abundance increased significantly with earlier first observed dates in the current and/or prior year. Three species (C. irus, C. henrici, a generalist) had more positive population trends in reserves than non-reserves. This suggests that C. irus declines correspond to habitat conditions. Thus, monitoring programs and habitat management specifically for C. irus appear necessary to obtain a long-term stable trend for this species in Wisconsin. PMID:26462687

  1. Twenty Years of Elfin Enumeration: Abundance Patterns of Five Species of Callophrys (Lycaenidae in Central Wisconsin, USA

    Directory of Open Access Journals (Sweden)

    Ann B. Swengel

    2014-04-01

    Full Text Available We recorded five species of elfins (Callophrys during annual spring surveys targeting frosted elfin C. irus (state-listed as threatened in 19 pine-oak barrens in central Wisconsin USA during 1994–2013. At the northwest end of its range here, C. irus co-varied with spring temperature, but declined significantly over time (eight sites verified extant of originally 17. Two other specialists increased significantly. The northern specialist, hoary elfin C. polios (nine sites, correlated positively with the previous year’s growing season precipitation. The southern specialist, Henry’s elfin C. henrici (11 sites, co-varied with winter precipitation and spring temperature and dryness. The two resident generalists had stable trends. For all species, the first observed date per year became earlier over time and varied more than the last observed date. Thus, flight period span increased with earlier first observed dates. Elfin abundance increased significantly with earlier first observed dates in the current and/or prior year. Three species (C. irus, C. henrici, a generalist had more positive population trends in reserves than non-reserves. This suggests that C. irus declines correspond to habitat conditions. Thus, monitoring programs and habitat management specifically for C. irus appear necessary to obtain a long-term stable trend for this species in Wisconsin.

  2. Increasing occurrence of high-intensity rainstorm events relevant for the generation of soil erosion in a temperate lowland region in Central Europe

    Science.gov (United States)

    Mueller, Eva Nora; Pfister, Angela

    2011-12-01

    SummaryRainfall times series with a high temporal resolution of 1 min for the Emscher-Lippe catchment area were analysed for trends in regard to erosion-relevant storm events with intensities larger than 0.3 mm/min (>20 mm/h) for the last 70 years using the Mann-Kendall test. The analysis data showed for all investigated stations an increase of rainstorm events with erosion-relevant rainfall intensities; the trend was more pronounced over the last 35 years and was shown to be statistical significant for a critical zone with rainfall characteristics of: intensity i Rain = 0.3-0.7 mm/min, duration t Rain = 2-10 min and depth h Rain = 1-3 mm. The increase of rainstorm events over the last 35 years was more pronounced in the summer season (July-September), but increases were detected also in the other seasons. The high-intensity storm events occured only ca. 4-15 times/year; the estimated trend increases of up to 0.5 events/year could therefore result in a multiplication of the occurrence of these storm events within only a few decades. This study has shown for the first time that the rainfall regime for temperate lowland regions in Germany has changed within its erosion-relevant spectrum over the last couple of decades. Parallel to the changes in the rainfall regime, increases in the annual and seasonal average temperature and changes in the occurrence of circulation patterns responsible for the generation of high-intensity storms were found, however not in the occurrence of thunderstorms. A climate-change driven increase of rain storm events over the last couple of decades and a potential future continuation of this trend may have several adverse effects for the study area and potentially for a larger region in Central Europe, for example an increase of soil erosion on slopes, the depletion of soil nutrients, an increased transport of nutrients and contaminants attached to sediment particles, their transfer into surface water bodies and consequential negative effects

  3. A method to integrate patterned electrospun fibers with microfluidic systems to generate complex microenvironments for cell culture applications.

    Science.gov (United States)

    Wallin, Patric; Zandén, Carl; Carlberg, Björn; Hellström Erkenstam, Nina; Liu, Johan; Gold, Julie

    2012-06-01

    The properties of a cell's microenvironment are one of the main driving forces in cellular fate processes and phenotype expression invivo. The ability to create controlled cell microenvironments invitro becomes increasingly important for studying or controlling phenotype expression in tissue engineering and drug discovery applications. This includes the capability to modify material surface properties within well-defined liquid environments in cell culture systems. One successful approach to mimic extra cellular matrix is with porous electrospun polymer fiber scaffolds, while microfluidic networks have been shown to efficiently generate spatially and temporally defined liquid microenvironments. Here, a method to integrate electrospun fibers with microfluidic networks was developed in order to form complex cell microenvironments with the capability to vary relevant parameters. Spatially defined regions of electrospun fibers of both aligned and random orientation were patterned on glass substrates that were irreversibly bonded to microfluidic networks produced in poly-dimethyl-siloxane. Concentration gradients obtained in the fiber containing channels were characterized experimentally and compared with values obtained by computational fluid dynamic simulations. Velocity and shear stress profiles, as well as vortex formation, were calculated to evaluate the influence of fiber pads on fluidic properties. The suitability of the system to support cell attachment and growth was demonstrated with a fibroblast cell line. The potential of the platform was further verified by a functional investigation of neural stem cell alignment in response to orientation of electrospun fibers versus a microfluidic generated chemoattractant gradient of stromal cell-derived factor 1 alpha. The described method is a competitive strategy to create complex microenvironments invitro that allow detailed studies on the interplay of topography, substrate surface properties, and soluble

  4. The subsurface geology of Central and Northern Negev with possible implications on the regional ground water flow pattern

    Science.gov (United States)

    Weinberger, G.; Rosenthal, E.; Flexer, A.

    1992-02-01

    The hydrogeological properties of the Kurnub Group sequence in the central and northern Negev were reassessed following a broadly expanding data base. Over most of the study area, the Kurnub Group is composed of permeable horizons. The most pronounced aquiferous zone extends in the belt of the three breached anticlines (Makhteshim) toward the Dead Sea area whereas the least impervious zone was discerned north- and northwestward from this belt. The present-day relief at the base of the Kurnub Group is outlined by prominent structural highs. Major structural depressions are located close to the Dead Sea as well as in northwestern Negev and in the Coastal Plain of the Negev and its offshore. Three major subsurface structures i.e. the Dabbeshet, Gerar and the Judea blocks were formed along parallel, NE-striking Upper Cretaceous reverse faults (preceding normal faults). The amount of vertical displacements along these faults generally exceeds the thickness of impervious layers over- and underlying the Kurnub Group thus facilitating groundwater flow from the Arad Group into the Kurnub sequence and from the latter into the Judea Group aquifer. It appears that the Kurnub Group aquifer plunges from the structural highs of Ramon and Kurnub, toward the Dead Sea 3utlet, to the Sharsheret-Sedot Akiva basin and beneath the Coastal Plain. It also plunges westward to Shezaf and to the Sukkot-Julie low and further beneath the shelf. The new geological evidence and its hydrogeological implications provide solutions for various previously unexplained salinization processes and hydrochemical phenomena such as the ever increasing salinity in the Beer Sheva well-field, the high salinities and the particularly low U-concentrations in groundwater extracted from the Judea Group aquifer south of Beer Sheva, their thermal anomalies and high Fe +2 concentrations.

  5. Patterns in abundance and diversity of faecally dispersed parasites of tiger in Tadoba National Park, central India

    Directory of Open Access Journals (Sweden)

    Jog Maithili M

    2002-05-01

    Full Text Available Abstract Background Importance of parasites in ecological and evolutionary interactions is being increasingly recognized. However, ecological data on parasites of important host species is still scanty. We analyze the patterns seen in the faecal parasites of tigers in the Tadoba National Park, India, and speculate on the factors and processes shaping the parasite community and the possible implications for tiger ecology. Results The prevalence and intensities were high and the parasite community was dominated by indirect life cycle parasites. Across all genera of parasites variance scaled with the square of the mean and there was a significant positive correlation between prevalence and abundance. There was no significant association between different types of parasites. Conclusions The 70 samples analyzed formed 14 distinct clusters. If we assume each of the clusters to represent individual tigers that were sampled repeatedly and that resident tigers are more likely to be sampled repeatedly, the presumed transient tigers had significantly greater parasite loads than the presumed resident ones.

  6. Demographic patterns and trends in Central Ghana: baseline indicators from the Kintampo Health and Demographic Surveillance System

    Directory of Open Access Journals (Sweden)

    Seth Owusu-Agyei

    2012-12-01

    Full Text Available Background: The dearth of health and demographic data in sub-Saharan Africa from vital registration systems and its impact on effective planning for health and socio-economic development is widely documented. Health and Demographic Surveillance Systems have the capacity to address the dearth of quality data for policy making in resource-poor settings. Objective: This article demonstrates the utility of the Kintampo Health and Demographic Surveillance System (KHDSS by showing the patterns and trends of population change from 2005 to 2009 in the Kintampo North Municipality and Kintampo South districts of Ghana through data obtained from the KHDSS biannual update rounds. Design: Basic demographic rates for fertility, mortality, and migration were computed by year. School enrolment was computed as a percentage in school by age and sex for 6–18 year-olds. Socio-economic status was derived by use of Principal Components Analysis on household assets. Results: Over the period, an earlier fertility decline was reversed in 2009; mortality declined slightly for all age-groups, and a significant share of working-age population was lost through out-migration. Large minorities of children of school-going age are not in school. Socio-economic factors are shown to be important determinants of fertility and mortality. Conclusion : Strengthening the capacity of HDSSs could offer added value to evidence-driven policymaking at local level.

  7. Massively parallel E-beam inspection: enabling next-generation patterned defect inspection for wafer and mask manufacturing

    Science.gov (United States)

    Malloy, Matt; Thiel, Brad; Bunday, Benjamin D.; Wurm, Stefan; Mukhtar, Maseeh; Quoi, Kathy; Kemen, Thomas; Zeidler, Dirk; Eberle, Anna Lena; Garbowski, Tomasz; Dellemann, Gregor; Peters, Jan Hendrik

    2015-03-01

    SEMATECH aims to identify and enable disruptive technologies to meet the ever-increasing demands of semiconductor high volume manufacturing (HVM). As such, a program was initiated in 2012 focused on high-speed e-beam defect inspection as a complement, and eventual successor, to bright field optical patterned defect inspection [1]. The primary goal is to enable a new technology to overcome the key gaps that are limiting modern day inspection in the fab; primarily, throughput and sensitivity to detect ultra-small critical defects. The program specifically targets revolutionary solutions based on massively parallel e-beam technologies, as opposed to incremental improvements to existing e-beam and optical inspection platforms. Wafer inspection is the primary target, but attention is also being paid to next generation mask inspection. During the first phase of the multi-year program multiple technologies were reviewed, a down-selection was made to the top candidates, and evaluations began on proof of concept systems. A champion technology has been selected and as of late 2014 the program has begun to move into the core technology maturation phase in order to enable eventual commercialization of an HVM system. Performance data from early proof of concept systems will be shown along with roadmaps to achieving HVM performance. SEMATECH's vision for moving from early-stage development to commercialization will be shown, including plans for development with industry leading technology providers.

  8. The invasive ctenophore Mnemiopsis leidyi in the central Baltic Sea: seasonal phenology and hydrographic influence on spatio-temporal distribution patterns

    DEFF Research Database (Denmark)

    Schaber, M.; Haslob, H.; Huwer, Bastian;

    2011-01-01

    In the Western Baltic, the invasive ctenophore Mnemiopsis leidyi was recorded for the first time in autumn 2006. An eastward propagation of the ctenophore into the central Baltic, and thus into important spawning grounds of major Baltic fish stocks, was observed in 2007. The focus of the present...... study was to investigate the seasonal phenology of this introduced species and whether it is able to form a self-sustaining population in this area. Therefore, the variability of temporal and spatial distribution of M. leidyi in the Bornholm Basin was analyzed over the first 4 years following...... the invasion and related to ambient hydrographic parameters. Results show a clear seasonal pattern. In contrast to the majority of other native and exotic habitats, the seasonal phenology showed highest abundances in spring and autumn months and only sporadic or even no appearance during summer. Vertical...

  9. The expression pattern of Adam10 in the central nervous system of adult mice: Detection by in situ hybridization combined with immunohistochemistry staining.

    Science.gov (United States)

    Guo, Zhi-Bao; Su, Ying-Ying; Wang, Yi-Hui; Wang, Wei; Guo, Da-Zhi

    2016-09-01

    ADAM10 (a disintegrin and metalloprotease 10) is a member of the ADAMs family, which is key in the development of the nervous system, by regulating proliferation, migration, differentiation and survival of various cells, including axonal growth and myelination. Previous studies have investigated the embryonic or postnatal expression of ADAM10, however, detailed information regarding its cellular distribution in the adult stage, to the best of our knowledge, is not available. The present study investigated the expression pattern of the ADAM10 gene in the adult mouse central nervous system (CNS) using an ADAM10 complementary RNA probe for in situ hybridization (ISH). Immunohistochemical staining was used to identify the type of the ISH staining‑positive cells with neuron‑ or astrocyte‑specific antibodies. The results of the current study demonstrated that the ADAM10 gene was predominantly expressed in the neurons of the cerebral cortex, hippocampus, thalamus and cerebellar granular cells in adult mouse CNS. PMID:27431484

  10. Synchronous degassing patterns of the neighbouring volcanoes Llaima and Villarrica in south-central Chile: the influence of tidal forces

    Science.gov (United States)

    Bredemeyer, Stefan; Hansteen, Thor H.

    2014-10-01

    The neighbouring volcanoes Villarrica and Llaima are two of the most active volcanoes in Chile and both currently degas continuously. We present a semi-continuous time series of SO2 fluxes for Villarrica and Llaima volcanoes. The time series was obtained using five scanning Mini-Differential Optical Absorption Spectrometers (Mini-DOAS, UV spectrometers) over 6 months (13 February to 31 July 2010) and is based on 6,829 scans for Villarrica and 7,165 scans for Llaima. Statistical analyses of the SO2 flux time series reveal a periodicity of degassing maxima about every 7 days, and further a conspicuous synchronicity of the degassing maxima and minima between the two volcanoes. Intra-day variations in SO2 fluxes also show a striking correlation between Villarrica and Llaima. All these patterns correlate well with the trend of the modelled solid Earth tide curves, where the 7-day degassing maxima correspond with both the fortnightly tidal maxima and minima. The intra-day degassing peaks mostly correlate well with the periods of maximum deformation rates during the diurnal tidal cycle, and further with semidiurnal minima in atmospheric pressure, a phenomenon we refer to as "the tidal pump". As there is little time lag between the tidal action and the changes in degassing rates, we infer that degassing at both volcanoes is controlled by conduit convection, involving physical separation between gas and magma at comparatively shallow levels. Variations in daily degassing rates were up to a factor of ca. 12 and 10 for Villarrica and Llaima, respectively, without any noticeable changes in the periodicity. We thus suggest that the described cyclic variations must be taken into account for all comparable volcanoes when using gas monitoring as a tool for volcanic hazard mitigation.

  11. Measuring citalopram in blood and central nervous system: revealing a distribution pattern that differs from other antidepressants.

    Science.gov (United States)

    Paulzen, Michael; Lammertz, Sarah E; Gründer, Gerhard; Veselinovic, Tanja; Hiemke, Christoph; Tauber, Simone C

    2016-05-01

    The aim of this study was to measure blood and cerebrospinal fluid concentrations of citalopram and its weakly active N-demethylated metabolite desmethylcitalopram to account for the distribution between the two compartments. The findings are discussed in the context with own preceding studies on the distribution pattern of different antidepressants. Concentrations of citalopram were measured in blood serum and cerebrospinal fluid of 18 patients treated with daily doses of 10-40 mg. Daily doses were correlated with serum and cerebrospinal fluid concentrations, and serum concentrations were correlated with concentrations in cerebrospinal fluid. Serum concentrations of citalopram and desmethylcitalopram showed no significant correlation to the daily dose, r=0.164, P=0.515, and r=0.174, P=0.505, respectively, whereas citalopram concentrations in serum and cerebrospinal fluid were highly correlated (r=0.763, Pcitalopram (total=bound+unbound concentration) varied between 0.14 and 0.86 (mean 0.35, SD 0.16). By correcting the mean cerebrospinal fluid/serum ratio for 80% plasma protein binding, cerebrospinal fluid concentrations of citalopram were on average 77% higher than the calculated unbound serum concentration with a ratio of 1.77 (SD 0.81, range 0.68-4.29). Findings indicate a very good ability of citalopram to cross the blood-brain and cerebrospinal fluid barrier. High concentrations of citalopram in the cerebrospinal fluid are indicative of active transport of citalopram into or missing active transport out of the cerebrospinal fluid. The results suggest a high ability of citalopram to enter the brain with sufficiently high drug concentrations at the target sites within the brain, contributing toward clinical efficacy. PMID:26650488

  12. Aluminium Accumulation and Intra-Tree Distribution Patterns in Three Arbor aluminosa (Symplocos) Species from Central Sulawesi.

    Science.gov (United States)

    Schmitt, Marco; Boras, Sven; Tjoa, Aiyen; Watanabe, Toshihiro; Jansen, Steven

    2016-01-01

    Accumulation of Aluminium (Al) at concentrations far above 1,000 mg kg-1 in aboveground plant tissues of Arbor aluminosa (Symplocos) species is the main reason why traditional Indonesian weavers rely on their leaves and bark as a mordant for dyeing textile. Recently, Symplocos species have become a flagship species for the conservation efforts of weaving communities due to their traditionally non-sustainable sampling and increasing demand for Symplocos plant material. Here we investigated Symplocos odoratissima, S. ophirensis and S. ambangensis at three montane rainforest sites in Central Sulawesi to measure Al levels in different tissues and organs. The highest Al concentrations were found in old leaves (24,180 ± 7,236 mg·kg-1 dry weight, mean ± SD), while young leaves had significantly lower Al levels (20,708 ± 7,025 mg·kg-1). Al accumulation was also lower in bark and wood tissue of the trunk (17,231 ± 8,356 mg·kg-1 and 5,181 ± 2,032 mg·kg-1, respectively). Two Al excluding species (Syzigium sp. and Lithocarpus sp.) contained only high Al levels in their roots. Moreover, no difference was found in soil pH (4.7 ± 0.61) and nutrient (K, Ca, Fe, Mg) availability at different soil levels and within or outside the crown of Symplocos trees, except for the upper soil layer. Furthermore, a positive and significant correlation between Al and Ca concentrations was found at the whole plant level for Symplocos, and at the leaf level for S. ophirensis and S. ambangensis, suggesting a potential role of Ca in Al uptake and/or detoxification within the plant. Our results provide evidence for strong Al accumulation in Symplocos species and illustrate that both Al accumulation and exclusion represent two co-occurring strategies of montane rainforest plants for dealing with Al toxicity. Indonesian weavers should be encouraged to harvest old leaves, which have the most efficient mordant capacity due to high Al concentrations.

  13. Stress patterns of the Plio-Quaternary brittle deformation along the Calama-Olacapato-El Toro Fault, Central Andes

    Science.gov (United States)

    Lanza, F.; Tibaldi, A.; Waite, G. P.; Corazzato, C.; Bonali, F.; Nardin, A.

    2012-04-01

    Understanding the geometry and kinematics of the major structures of an orogen is essential to elucidate its style of deformation, as well as its tectonic evolution. We describe the temporal and spatial changes in the state of stress of the trans-orogen area of the Calama-Olacapato-El Toro (COT) Fault Zone in the Central Andes, at about 24° S within the northern portion of the Puna Plateau between the Argentina-Chile border. The importance of the COT derives principally from the Quaternary-Holocene activity recognized on some segments, which may shed new light on its possible control on Quaternary volcanism and on the seismic hazard assessment of the area. Field geological surveys along with kinematic analysis and numerical inversion of ~ 280 new fault-slip measurements have revealed that this portion of the COT consists mainly of NW-SE striking faults, which have been reactivated under three different kinematic regimes: 1) a Miocene transpressional phase with the maximum principal stress (σ1) chiefly trending NW-SE; 2) an extensional phase that started by 9 Ma, with a horizontal NW-SE-trending minimum principal stress (σ3) - permutations between σ2 and σ3 axes have been recognized at three sites - and 3) a left-lateral strike-slip phase with an ~ ENE-WSW σ1 and a ~ NNW-SSE σ3 dating to the late Pliocene-Quaternary. Spatially, in the Quaternary, the left-lateral component decreases toward the westernmost tip of the COT, where it transitions to extension; this produced to a N-S horst and graben structure. Hence, even if trascurrence is still active in the eastern portion of the COT, as focal mechanisms of crustal earthquakes indicate, our study demonstrates that extension is becoming the predominant structural style of deformation, at least in the western region. These major temporal and spatial changes in the tectonic regimes are attributed in part to changes in the magnitude of the boundary forces due to subduction processes. The overall perpendicular

  14. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    OpenAIRE

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented o...

  15. Central Asia in a Changing World: From a Peripheral Region to an Area of Policy Generation and Application. Actors, Policy and Security

    Directory of Open Access Journals (Sweden)

    Nora Sainz Gsell

    2005-10-01

    Full Text Available This work deals with Central Asia, beginning with an analysis of the characteristics of international insertion of the area as a whole and of the former Soviet republics that comprise it. In a general way, it aims to analyse the evolution of Central Asia from a peripheral region to an area that generates behaviours and receives the application of policies on the part ofinternational actors. In the first part of the study, it mentions a series of particularities of the republics that have determined the relationships in the region(the Central Asian order and those between the region and the outside world; it indicates geo-historical and economic-strategic aspects. In the second part, it examines the foreign policy of the republics in the post-Cold War era from the singularities of domestic policy. And, in the third part, it analyses, according to the aforementioned peculiarities, the policies that the area and each State has generated in international actors, both regional ones and global ones, and which have transformed the region from a peripheral one to a geopolitically emerging one.

  16. Formation of sulphation deposits in cables in the electricity generation plant of Los Humeros geothermal field, Mexico; Sulfatacion de cables en la central geotermoelectrica Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vergara Rangel, Agustin [Comision Federal de Electricidad, Perote, Veracruz (Mexico)

    2000-12-01

    In the construction of a central electrical generation plant using geothermal fluids, high quality standards are applied in all aspects of engineering. Los Humeros generation units were installed through trenches, ducts and trays according to norms for cables of control, force and power, specifically in point to point cables and connections. Performance of the power plant has been affected by electric momentary and sequence flaws due to problems of cable sulfating, which were solved by tinning the conductors. [Spanish] En la construccion de centrales generadoras de electricidad con fluidos geotermicos se aplican criterios de calidad de diseno en todos los aspectos de la ingenieria. En Los Humeros Puebla, se realizo la instalacion conforme a normas de cables de control, fuerza y potencia a traves de trincheras, ductos y charolas y especificamente en el cableado asi como en las conexiones de punta a punta. Todos estos aspectos son referidos a planos de los componentes y equipos electricos existentes en una central. Al paso del tiempo existieron fallas electricas momentaneas y secuenciales por el problema de sulfatacion en cables, los cuales fueron resueltos con el estanado de conductores.

  17. A model of co-occurrence: segregation and aggregation patterns in the mycoflora of the crayfish Procambarus clarkii in Lake Trasimeno (central Italy

    Directory of Open Access Journals (Sweden)

    Antonia C. Elia

    2012-01-01

    Full Text Available Although attention on crayfish diseases has recently proliferated, the focus is mainly on a single host-parasite relationship rather than analyzing the entire mycoflora, probably due to the fact that (1 some diseases are occasional (pathogens of which are of difficult collection and (2 economic impact is more relevant in aquaculture (i.e., a controlled environment where only few parasites occur than in natural conditions. Contrary to this viewpoint, fungal ectoparasites assume a great importance since they are integral components in shaping community, ecosystem structure, and energy flow. Here we described the fungal species co-occurrence patterns (species segregation/ aggregation using null models comparing the occurrence frequencies of ectosymbiots through host individuals with those expected by chance. Non-indigenous crayfish species like Procambarus clarkii allow to observe phenomena of competitive exclusion (segregation or mutualism (aggregation amongst fungi. We analyzed the fungal species occurrence on 86 host crayfish monthly collected from June 2007 to June 2008 in the Lake Trasimeno (Central Italy. A total of 29 fungal taxa were detected. Taxa showed a particular fungal assemblage with a great species variation depending on sampling month and crayfish sex, size, and body region. In particular, fungal species showed different occurrence patterns in both richness and segregation/ aggregation. The fungal community shows a non-random structure not in all cases, with the majority of tests indicating segregation, not aggregation of ectosymbiontic species on hosts. The non-random patterns of fungal co-occurrence in some cases suggest that some temporally or spatially variable factors are responsible for the establishment of the mycoflora community assemblage. We also detected temporal differences in fungal co-occurrences patterns. Regarding seasonal samples, the same analyses showed a competitive structure only in the sub-communities found on

  18. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented opportunities for the development of novel therapeutics. PMID:21921682

  19. Characterization of alternative electric generation technologies for the SPS comparative assessment: volume 2, central-station technologies

    International Nuclear Information System (INIS)

    The SPS Concept Development and Evaluation Program includes a comparative assessment. An early first step in the assessment process is the selection and characterization of alternative technologies. This document describes the cost and performance (i.e., technical and environmental) characteristics of six central station energy alternatives: (1) conventional coal-fired powerplant; (2) conventional light water reactor (LWR); (3) combined cycle powerplant with low-Btu gasifiers; (4) liquid metal fast breeder reactor (LMFBR); (5) photovoltaic system without storage; and (6) fusion reactor

  20. Characterization of alternative electric generation technologies for the SPS comparative assessment: volume 2, central-station technologies

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    The SPS Concept Development and Evaluation Program includes a comparative assessment. An early first step in the assessment process is the selection and characterization of alternative technologies. This document describes the cost and performance (i.e., technical and environmental) characteristics of six central station energy alternatives: (1) conventional coal-fired powerplant; (2) conventional light water reactor (LWR); (3) combined cycle powerplant with low-Btu gasifiers; (4) liquid metal fast breeder reactor (LMFBR); (5) photovoltaic system without storage; and (6) fusion reactor.

  1. Examining runoff generation processes in the Selke catchment in central Germany: Insights from data and semi-distributed numerical model

    Directory of Open Access Journals (Sweden)

    Sumit Sinha

    2016-09-01

    New hydrological insights for the region: We examined the spatio-temporal variation of runoff generating mechanisms on the sub-basin level on seasonal basis. Our analysis reveals that the runoff generation in the Selke catchment is primarily dominated by shallow sub-surface flow and very rarely the contribution from Dunne overland flow exceeds sub-surface flow. Runoff generated by Hortonian mechanism is very infrequent and almost negligible. We also examined the spatio-temporal variation of runoff coefficients on seasonal basis as well as for individual storms. Due to higher precipitation and topographic relief in the upland catchment of Silberhutte, the runoff coefficients were consistently higher and its peak was found in winter months due to lower evapotranspiration.

  2. A Comparison of Optimal Operation of a Residential Fuel Cell Co-Generation System Using Clustered Demand Patterns Based on Kullback-Leibler Divergence

    Directory of Open Access Journals (Sweden)

    Takumi Hasizume

    2013-01-01

    Full Text Available When evaluating residential energy systems like co-generation systems, hot water and electricity demand profiles are critical. In this paper, the authors aim to extract basic time-series demand patterns from two kinds of measured demand (electricity and domestic hot water, and also aim to reveal effective demand patterns for primary energy saving. Time-series demand data are categorized with a hierarchical clustering method using a statistical pseudo-distance, which is represented by the generalized Kullback-Leibler divergence of two Gaussian mixture distributions. The classified demand patterns are built using hierarchical clustering and then a comparison is made between the optimal operation of a polymer electrolyte membrane fuel cell co-generation system and the operation of a reference system (a conventional combination of a condensing gas boiler and electricity purchased from the grid using the appropriately built demand profiles. Our results show that basic demand patterns are extracted by the proposed method, and the heat-to-power ratio of demand, the amount of daily demand, and demand patterns affect the primary energy saving of the co-generation system.

  3. Erosividade e padrões hidrológicos de precipitação no Agreste Central pernambucano Erosivity and rainfall hydrological patterns in the Pernambuco Central 'Agreste'

    Directory of Open Access Journals (Sweden)

    Thais E. M. dos Santos

    2012-08-01

    Full Text Available A principal forma de erosão nas condições brasileiras é a causada pela energia cinética do impacto das gotas de chuva sobre a superfície do solo, desencadeando o processo de erosão hídrica. Desenvolveu-se o presente trabalho com o objetivo de avaliar o índice de erosividade (EI30 e caracterizar o padrão hidrológico das chuvas do Agreste Central pernambucano, considerando-se uma série de 29 anos de dados, ficando patente que o primeiro semestre do ano é caracterizado pela ocorrência de chuvas de elevado potencial erosivo. O valor do fator "R" da equação universal de perda de solo para a região estudada é de 2.779,79 MJ mm ha-1 h-1. O padrão de chuva de maior ocorrência é o avançado, seguido do intermediário e atrasado, com 46,57; 36,38 e 17,19% dos totais de chuvas erosivas analisados, respectivamente. Não foram encontradas correlações significativas entre erosividade, coeficiente de chuva e precipitação.The main form of erosion in Brazilian conditions is caused by the kinetic energy of the impact of raindrops on the soil surface, triggering the erosion process. The present study was conducted with the aim to evaluate the erosivity index (EI30, as well as to characterize the hydrological pattern of rainfall in the Pernambuco Central 'Agreste', considering a series of 29 years of data. It was found that the first half of the year is characterized by rain with high erosive potential. The value of the factor "R" in the Universal equation of soil loss for the studied region is 2,779.79 MJ mm ha-1 h-1. The rain pattern of higher occurrence is the advanced, followed by intermediate and delayed, with 46.57; 36.38 and 17.19% of total erosive rainfall analyzed, respectively. There were no significant correlations between erosivity, rainfall coefficient and precipitation.

  4. Are Dietary Patterns of Mothers during Pregnancy Related to Childrens Weight Status? Evidence from the Lifeways Cross-Generational Cohort Study

    Directory of Open Access Journals (Sweden)

    Celine M Murrin

    2015-07-01

    Full Text Available Children's diet patterns are likely to be influenced by their mothers' diet pattern. The primary objective of this study was to examine whether children's adiposity could be influenced by diet patterns of mothers during pregnancy. A secondary objective was to study the relative influence of fathers' and children's dietary patterns on childhood adiposity. The design was a prospective cross-generational cohort study initiated with 1,124 mothers recruited during pregnancy. Self-reported questionnaires included a food frequency instrument (FFQ to assess parental intakes during the perinatal period. Child body mass index (BMI was measured at 5 years and an age-appropriate FFQ was administered. Dietary patterns for each group were identified by principal components analysis. Pearson's correlation and logistic regression were used to test for associations. Dietary patterns were described for n = 1,042 mothers during pregnancy and n = 331 fathers during the perinatal period. Dietary patterns and BMI data were available for n = 443 children at age 5 years. The diet patterns identified for mothers correlated with the corresponding diet patterns for fathers. The children's “pasta & vegetable” pattern was positively correlated with “healthy patterns” in mothers (r = 0.195, p < 0.01 and fathers (r = 0.250, p < 0.01. The children's “junk” food pattern was correlated with the “processed” pattern in mothers (r = 0.245, p < 0.01 and fathers (r = 0.257, p < 0.01. In multivariate logistic regression analysis the upper tertiles of children's “cereal and juice” [Tertile 2 (T2: OR 0.44, 95% CI (0.22-0.90; T3: 0.41, (0.19-0.85] and the middle tertile of the “pasta and veg” patterns [T3: 0.37, (0.18-0.75] were negatively associated with overweight and obesity. The mothers' processed pattern during pregnancy was positively associated with offspring overweight and obesity [T2: 2.64, (1.28-5.45; T3: 2.03, (0.87-4.73]. No significant associations

  5. Satellite-measured interannual variability of turbid river plumes off central-southern Chile: Spatial patterns and the influence of climate variability

    Science.gov (United States)

    Saldías, Gonzalo S.; Largier, John L.; Mendes, Renato; Pérez-Santos, Iván; Vargas, Cristian A.; Sobarzo, Marcus

    2016-08-01

    Ocean color imagery from MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the Aqua platform is used to characterize the interannual variability of turbid river plumes off central-southern Chile. Emphasis is placed on the influence of climate fluctuations, namely El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Antarctic Oscillation (AAO). Additional satellite data on wind, boat-based hydrographic profiles, and regional climate indices are used to identify the influence of climate variability on the generation of anomalous turbid river plumes. The evolution of salinity at a coastal station on the 90 m isobath between the Itata and Biobío Rivers shows a freshwater surface layer with salinity importance of long-term and high-resolution ocean color observations for studying the temporal evolution of river plumes.

  6. Satellite-measured interannual variability of turbid river plumes off central-southern Chile: Spatial patterns and the influence of climate variability

    Science.gov (United States)

    Saldías, Gonzalo S.; Largier, John L.; Mendes, Renato; Pérez-Santos, Iván; Vargas, Cristian A.; Sobarzo, Marcus

    2016-08-01

    Ocean color imagery from MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the Aqua platform is used to characterize the interannual variability of turbid river plumes off central-southern Chile. Emphasis is placed on the influence of climate fluctuations, namely El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Antarctic Oscillation (AAO). Additional satellite data on wind, boat-based hydrographic profiles, and regional climate indices are used to identify the influence of climate variability on the generation of anomalous turbid river plumes. The evolution of salinity at a coastal station on the 90 m isobath between the Itata and Biobío Rivers shows a freshwater surface layer with salinity implications of plume events and the importance of long-term and high-resolution ocean color observations for studying the temporal evolution of river plumes.

  7. 基于拓扑构型的地毯图案生成方法%A Generation Method of Carpet Pattern Based on Topology Configuration

    Institute of Scientific and Technical Information of China (English)

    赵海英; 彭宏; 杨一帆; 徐正光

    2013-01-01

    Traditional fabric patterns generally contain certain basic elements which are characteristically distributed. However, the existing pattern generation methods based on characteristics and examples preserve neither the integrity of elements and structures in pattern, nor the information of styles and levels, such as distribution characteristics. Thus, taking Xinjiang carpet design as an example, an auto-generating method of patterns based on topological structure is presented. By interactively identifying patterns with different perception layers to serve as templates and extracting elements of the same class accurately by template-matching algorithm, pattern topological structure is generated. Then, appropriate patterns are extracted after the design of selection rules. Finally, the matrix mark method is used to embed the pattern. The experimental results show that the method not only solves the overlapping problem of pattern elements, but also generates beautifully-layered patterns that can express the composition, element image and color of the fabric prints, which can meet the design requirements of style inheritance.%传统的织物图案中通常包含按一定特征分布的基本元素,而现有基于特征和实例的图案生成方法难以保持图案中基本纹样元素与结构特征的完整性以及分布特征等基于风格层次的信息.文中以新疆地毯图案为例,提出一种基于拓扑构型的图案自动生成方法.将交互标识出的不同感知层的图案元素作为模板,并约束模板匹配算法较准确地提取同类图案元素,生成图案拓扑构型;再设计选择规则,提取合适的图案纹样.最后利用所提出的标识矩阵法进行纹样嵌图,结果表明,该方法不仅解决了图案元素重叠的问题,而且能生成体现织物图案的构图、元素形象和色彩的具有层次美感的图案,满足风格传承的设计要求.

  8. Soil cover patterns and SOC dynamics impacts on the soil processes, land management and ecosystem services in Central Region of Russia

    Science.gov (United States)

    Vasenev, Ivan; Chernikov, Vladimir; Yashin, Ivan; Geraskin, Mikhail; Morev, Dmitriy

    2014-05-01

    In the Central Region of Russia (CRR) the soil cover patterns usually play the very important role in the soil forming and degradation processes (SFP & SDP) potential and current rates, soil organic carbon (SOC) dynamics and pools, greenhouse gases (GHG) emissions and soluble SOC fluxes that we need take into attention for better assessment of the natural and especially man-changed ecosystems' services and for best land-use practices development. Central Region of Russia is the biggest one in RF according to its population and role in the economy. CRR is characterized by high spatial variability of soil cover due to as original landscape heterogeneity as complicated history of land-use practices during last 700 years. Our long-term researches include the wide zonal-provincial set of representative ecosystems and soil cover patterns with different types and history of land-use (forest, meadow-steppe and agricultural ones) from middle-taiga to steppe zones with different level of continentality. The carried out more than 30-years region- and local-scale researches of representative natural and rural landscapes in Tver', Yaroslavl', Kaluga, Moscow, Vladimir, Saransk (Mordovia), Kursk, Orel, Tambov, Voronezh and Saratov oblasts give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different soil forming and degradation processes rates and soil organic carbon dynamics due to regionally specific soil-geomorphologic features, environmental and dominated microclimate conditions, land-use current practices and history. The validation and ranging of the limiting factors of SFP and SDP develop¬ment, soil carbon dynamics and sequestration potential, ecosystem (agroecosystem) principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of SOC structure analysis, regional and local GIS, soil spatial patterns detail

  9. Patterns of soil carbon and nitrogen in relation to soil movement under different land uses in mountain farmland fields (South Central Pyrenees)

    Science.gov (United States)

    Navas, A.; Gaspar, L.; López-Vicente, M.; Machín, J.

    2009-04-01

    Cultivation on mountain landscapes has been identified as a main factor triggering soil erosion. The loss of soil particles and its redistribution across the landscape is associated to that of soil nutrients. Patterns of soil erosion and of the transport and redistribution of soil particles appear to be closely linked to that of carbon in soils. In this work the redistribution of total organic carbon and nitrogen and that of soil particles is analysed in different geomorphic parts of mountain farmland fields. A southern orientated hillslope in the Central Spanish Pyrenees was selected as representative of main land uses. In the region, farmland abandonment during the last decades affects 74 % of its surface and therefore patterns of soil and nutrient losses in the fields are affected by land abandonments and tillage. A set of cultivated and abandoned fields with different ages of land abandonment, slope gradients and length were selected to conduct this study. In each of the fields, sampling was carried out in different parts of the slope to assess the pattern of particle size distribution and of total organic carbon (TOC) and total nitrogen (TN). Other general soil properties analysed: pH, EC and carbonate contents provided supplementary information for better understanding soil and nutrient redistribution patterns. In addition, information provided by a previous research using fallout caesium 137 was used to document soil movement in these fields. At the bottom slope of the fields significant increases in the sand percentage occurs whereas the clay contents decrease slightly. This could be due to the export of the finest fractions with high runoff in spite that fields are surrounded with stone walls as well as to some clay leaching in the soil profile, as suggested by the lowest values of EC at the bottom of the slope. The results indicate that in general TOC increases from the crest to the bottom slope of the fields. Percentages of TOC increases range from 5 to

  10. Generational changes in materialism and work centrality, 1976-2007: associations with temporal changes in societal insecurity and materialistic role modeling.

    Science.gov (United States)

    Twenge, Jean M; Kasser, Tim

    2013-07-01

    We examined whether culture-level indices of threat, instability, and materialistic modeling were linked to the materialistic values of American 12th graders between 1976 and 2007 (N = 355,296). Youth materialism (such as the importance of money and of owning expensive material items) increased over the generations, peaking in the late 1980s to early 1990s with Generation X and then staying at historically high levels for Millennials (GenMe). Societal instability and disconnection (e.g., unemployment, divorce) and social modeling (e.g., advertising spending) had both contemporaneous and lagged associations with higher levels of materialism, with advertising most influential during adolescence and instability during childhood. Societal-level living standards during childhood predicted materialism 10 years later. When materialistic values increased, work centrality steadily declined, suggesting a growing discrepancy between the desire for material rewards and the willingness to do the work usually required to earn them. PMID:23637277

  11. Nearshore human interventions reverse patterns of decline in lake calcium budgets in central Ontario as demonstrated by mass-balance analyses

    Science.gov (United States)

    Yao, Huaxia; McConnell, Christopher; Somers, Keith M.; Yan, Norman D.; Watmough, Shaun; Scheider, Wolfgang

    2011-06-01

    Calcium (Ca) has declined to levels threatening aquatic biota in lakes on the eastern Canadian Shield. Predictive models for future changes in lake Ca are generally based on catchment-scale studies, but these models rarely account for unmeasured sources of Ca supply that are common in the nearshore areas of developed lakes. In this study we utilize up to 29 years of hydrological and water chemistry data for three lakes in central Ontario that differ in degree of human intervention to demonstrate that shoreline development may exert large effects on Ca mass balances. In the relative absence of shoreline development, Red Chalk Lake exhibited what we consider to be the normal response, a reduction in Ca load from the catchment over the last three decades, leading to a reduction in lake export and lake Ca concentration. Calcium load, export, and lake water Ca concentration also fell in Harp Lake, but less than in Red Chalk Lake, because Ca loads were elevated by human activities in Harp Lake's moderately developed shoreline area. By contrast, Dickie Lake experienced an exceptional change in Ca dynamics: both export and lake concentrations rose because of elevated load from the shoreline area linked to the use of dust suppressants on gravel roads. Reductions in both stream Ca concentration and flow volume have led to calcium decline in streams and lakes. Long-term soil acidification processes and climatic variability with its link to hydrology can explain the general pattern of Ca decline in lakes on the south-central Canadian Shield. However, given the widespread lakeshore development and use of dust suppressants on gravel roads, predictions of lake Ca levels need to take into account nearshore activities, especially those that augment rates of Ca supply.

  12. Modelling forest lines and forest distribution patterns with remote sensing data in a mountainous region of semi-arid Central Asia

    Directory of Open Access Journals (Sweden)

    M. Klinge

    2014-10-01

    Full Text Available Satellite images and digital elevation models provide an excellent database to analyse forest distribution patterns and forest limits in the mountain regions of semi-arid Central Asia at the regional scale. For the investigation area in the northern Tien Shan a strong relation between forest distribution and climate conditions could be found. Additionally areas of potential human impact on forested areas are identified at lower elevations near the mountain border based on an analysis of the differences of climatic preconditions and present occurrence of forest stands. The distribution of spruce (Picea schrenkiana forests is hydrologically limited by a minimum annual precipitation of 250 mm and thermally by a minimum monthly mean temperature of 5 °C during the growing season. While the actual lower forest limit increases from 1600 m a.s.l. in the northwest to 2600 m a.s.l. in the southeast, the upper forest limit takes the same course from 1800 to 2900 m a.s.l. In accordance with the main wind directions, the steepest gradient of both forest lines and the greatest local vertical extent of the forest belt of 500 to 600 m and maximum 900 m occur at the northern and western mountain fronts. The forests in the investigation area are strongly restricted to north facing-slopes, which is a common feature in semi-arid Central Asia. Based on the presumption that variations in local climate conditions are a function of topography, the potential forest extent was analysed with regard to the parameters slope, aspect, solar radiation input and elevation. All four parameters showed a strong relationship to forest distribution, yielding a total potential forest area that is 3.5 times larger than the present forest remains of 502 km2.

  13. GEODYNAMICS OF NAZCA RIDGE’S OBLIQUE SUBDUCTION AND MIGRATION - IMPLICATIONS FOR TSUNAMI GENERATION ALONG CENTRAL AND SOUTHERN PERU: Earthquake and Tsunami of 23 June 2001

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2012-01-01

    Full Text Available Peru is in a region of considerable geologic and seismic complexity. Thrust faulting along the boundary where the Nazca plate subducts beneath the South American continent has created three distinct seismic zones. The angle of subduction of the Nazca oceanic plate beneath the South American plate is not uniform along the entire segment of the Peru-Chile Trench. Furthermore, subduction is affected by buoyancy forces of the bounding oceanic ridges and fractures - such as the Mendana Fracture Zone (MFZ to the North and the Nazca Ridge to the South. This narrow zone is characterized by shallow earthquakes that can generate destructive tsunamis of varied intensities. The present study examines the significance of Nazca Ridge’s oblique subduction and migration to the seismicity of Central/Southern Peru and to tsunami generation. The large tsunamigenic earthquake of 23 June 2001 is presented as a case study. This event generated a destructive, local tsunami that struck Peru’s southern coasts with waves ranging from 3 to 4.6 meters (10-15 feet and inland inundation that ranged from 1 to 3 km. In order to understand the near and far-field tsunamigenic efficiency of events along Central/Southern Peru and the significance of Nazca Ridge’s oblique subduction, the present study examines further the geologic structure of the region and this quake’s moment tensor analysis, energy release, fault rupture and the spatial distribution of aftershocks. Tsunami source mechanism characteristics for this event are presented, as inferred from seismic intensities, energy releases, fault plane solutions and the use of empirical relationships. The study concludes that the segment of subduction and faulting paralleling the Peru-Chile Trench from about 150 to 180 South, as well as the obliquity of convergent tectonic plate collision in this region, may be the reason for shorter rupture lengths of major earthquakes and the generation of only local destructive tsunamis.

  14. Soil cover patterns influence on the land environmental functions, agroecological quality, land-use and monitoring efficiency in the Central Russia

    Science.gov (United States)

    Vasenev, Ivan; Yashin, Ivan; Lukin, Sergey; Valentini, Riccardo

    2015-04-01

    First decades of XXI century actualized for soil researches the principal methodical problem of most modern geosciences: what spatial and temporal scale would be optimal for land quality evaluation and land-use practice optimizing? It is becoming obvious that this question cannot have one solution and have to be solved with especial attention on the features of concrete region and landscape, land-use history and practical issues, land current state and environmental functions, soil cover patterns and variability, governmental requirements and local society needs, best available technologies and their potential profitability. Central Russia is one of the most dynamical economic regions with naturally high and man-made complicated landscape and soil cover variability, long-term land-use history and self-contradictory issues, high potential of profitable farming and increased risks of land degradation. Global climate and technological changes essentially complicate the originally high and sharply increased in XX century farming land heterogeneity in the Central Russia that actualizes system analysis of its zonal, intra-zonal and azonal soil cover patterns according to their influence on land environmental functions, agroecological quality, and land-use and monitoring efficiency variability. Developed by the Laboratory of agroecological monitoring, ecosystem modeling & prediction (LAMP / RTSAU with support of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) regional systems of greenhouse gases environmental monitoring RusFluxNet (6 fixed & 1 mobile eddy covariance stations with zonal functional sets of key plots with chamber investigations in 5 Russian regions) and of agroecological monitoring (in representative key plots with different farming practice in 9 RF regions) allow to do this analysis in frame of enough representative regional multi-factorial matrix of soil cover patterns, bioclimatic conditions, landscape features, and land-use history and

  15. Monitoring Hydrological Patterns of Temporary Lakes Using Remote Sensing and Machine Learning Models: Case Study of La Mancha Húmeda Biosphere Reserve in Central Spain

    Directory of Open Access Journals (Sweden)

    Carolina Doña

    2016-07-01

    Full Text Available The Biosphere Reserve of La Mancha Húmeda is a wetland-rich area located in central Spain. This reserve comprises a set of temporary lakes, often saline, where water level fluctuates seasonally. Water inflows come mainly from direct precipitation and runoff of small lake watersheds. Most of these lakes lack surface outlets and behave as endorheic systems, where water withdrawal is mainly due to evaporation, causing salt accumulation in the lake beds. Remote sensing was used to estimate the temporal variation of the flooded area in these lakes and their associated hydrological patterns related to the seasonality of precipitation and evapotranspiration. Landsat 7 ETM+ satellite images for the reference period 2013–2015 were jointly used with ground-truth datasets. Several inverse modeling methods, such as two-band and multispectral indices, single-band threshold, classification methods, artificial neural network, support vector machine and genetic programming, were applied to retrieve information on the variation of the flooded areas. Results were compared to ground-truth data, and the classification errors were evaluated by means of the kappa coefficient. Comparative analyses demonstrated that the genetic programming approach yielded the best results, with a kappa value of 0.98 and a total error of omission-commission of 2%. The dependence of the variations in the water-covered area on precipitation and evaporation was also investigated. The results show the potential of the tested techniques to monitor the hydrological patterns of temporary lakes in semiarid areas, which might be useful for management strategy-linked lake conservation and specifically to accomplish the goals of both the European Water Framework Directive and the Habitats Directive.

  16. A Priori and a Posteriori Dietary Patterns during Pregnancy and Gestational Weight Gain: The Generation R Study

    Directory of Open Access Journals (Sweden)

    Myrte J. Tielemans

    2015-11-01

    Full Text Available Abnormal gestational weight gain (GWG is associated with adverse pregnancy outcomes. We examined whether dietary patterns are associated with GWG. Participants included 3374 pregnant women from a population-based cohort in the Netherlands. Dietary intake during pregnancy was assessed with food-frequency questionnaires. Three a posteriori-derived dietary patterns were identified using principal component analysis: a “Vegetable, oil and fish”, a “Nuts, high-fiber cereals and soy”, and a “Margarine, sugar and snacks” pattern. The a priori-defined dietary pattern was based on national dietary recommendations. Weight was repeatedly measured around 13, 20 and 30 weeks of pregnancy; pre-pregnancy and maximum weight were self-reported. Normal weight women with high adherence to the “Vegetable, oil and fish” pattern had higher early-pregnancy GWG than those with low adherence (43 g/week (95% CI 16; 69 for highest vs. lowest quartile (Q. Adherence to the “Margarine, sugar and snacks” pattern was associated with a higher prevalence of excessive GWG (OR 1.45 (95% CI 1.06; 1.99 Q4 vs. Q1. Normal weight women with higher scores on the “Nuts, high-fiber cereals and soy” pattern had more moderate GWG than women with lower scores (−0.01 (95% CI −0.02; −0.00 per SD. The a priori-defined pattern was not associated with GWG. To conclude, specific dietary patterns may play a role in early pregnancy but are not consistently associated with GWG.

  17. Focusing by blocking: Repeatedly generating central density peaks in self-propelled particle systems by exploiting diffusive processes

    Science.gov (United States)

    Menzel, Andreas M.

    2015-05-01

    Over the past few years the displacement statistics of self-propelled particles has been intensely studied, revealing their long-time diffusive behavior. Here, we demonstrate that a concerted combination of boundary conditions and switching on and off the self-propelling drive can generate and afterwards arbitrarily often restore a non-stationary centered peak in their spatial distribution. This corresponds to a partial reversibility of their statistical behavior, in opposition to the above-mentioned long-time diffusive nature. Interestingly, it is a diffusive process that mediates and makes possible this procedure. It should be straightforward to verify our predictions in a real experimental system.

  18. Associations between forest fragmentation patterns and geneticstructure in Pfrimer’s Parakeet (Pyrrhura pfrimeri), an endangered endemic to central Brazil’s dry forests

    Science.gov (United States)

    Haig, Susan M.; Miller, Leonard F.; Bianchi, Carlos; Mullins, Thomas D.

    2012-01-01

    When habitat becomes fragmented, populations of species may become increasingly isolated. In the absence of habitat corridors, genetic structure may develop and populations risk reductions in genetic diversity from increased genetic drift and inbreeding. Deforestation of the Cerrado biome of Brazil, particularly of the dry forests within the Parana˜ River Basin, has incrementally occurred since the 1970s and increased forest fragmentation within the region. We performed landscape genetic analyses of Pfrimer’s parakeet (Pyrrhura pfrimeri), a globally endangered endemic to the region, to determine if forest fragmentation patterns were associated with genetic structuring in this species. We used previously generated satellite imagery that identified the locations of Parana˜ River Basin forest fragments in 1977, 1993/94, and 2008. Behavioral data quantifying the affinity of Pfrimer’s parakeet for forest habitat was used to parameterize empirically derived landscape conductance surfaces. Though genetic structure was observed among Pfrimer’s parakeet populations, no association between genetic and geographic distance was detected. Likewise, least cost path lengths, circuit theorybased resistance distances, and a new measure of least cost path length complexity could not be conclusively associated with genetic structure patterns. Instead, a new quantity that encapsulated connection redundancy from the 1977 forest fragmentation data provided the clearest associations with pairwise genetic differentiation patterns (Jost’s D: r = 0.72, P = 0.006; FST: r = 0.741, P = 0.001). Our analyses suggest a 35-year or more lag between deforestation and its effect on genetic structure. Because 66 % of the Parana˜ River Basin has been deforested since 1977, we expect that genetic structure will increase substantially among Pfrimer’s Parakeet populations in the future, especially if fragmentation continues at its current pace.

  19. Methodology for generation of heliostat field layout in central receiver systems based on yearly normalized energy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marcelino; Romero, Manuel [DER-Plataforma Solar de Almeria, CIEMAT, Avda. Complutense 22, E-28040 Madrid (Spain)

    2006-07-15

    The heliostat field layout is an essential task for any solar tower plant optimization process. Radially staggered and other distributions are usually optimised by computer codes using different approaches. In most of those cases, due to the CPU time required, the heliostat field layout is optimised by several mathematical models and simplifications. With today's computers, it is possible to calculate the yearly energy available at any point in a site for a given tower height, the yearly normalized energy surface (YNES). Yearly efficiency maps can be generated based on the cosine factor, the spillage factor and the atmospheric attenuation coefficient of the site using real Direct Normal Irradiance (DNI) data, within a reasonable computing time. It is therefore easy to find the place where the yearly energy available is the highest for location of the first heliostat. It is also possible to calculate the effect of shadowing and blocking by this heliostat on the YNES, so YNES can be re-calculated and the best position for the next heliostat can be found. Although this iterative method is time-consuming, it is worthwhile if either the efficiency of the solar plant can be increased or the capital cost reduced. This YNES-based layout generation method enables better flexibility than pre-determined gridding strategies such as used in DELSOL. The paper includes a description of the optimization procedure. (author)

  20. Alternative mRNA Splicing from the Glial Fibrillary Acidic Protein (GFAP) Gene Generates Isoforms with Distinct Subcellular mRNA Localization Patterns in Astrocytes

    DEFF Research Database (Denmark)

    Thomsen, Rune; Daugaard, Tina Fuglsang; Holm, Ida E;

    2013-01-01

    The intermediate filament network of astrocytes includes Glial fibrillary acidic protein (Gfap) as a major component. Gfap mRNA is alternatively spliced resulting in generation of different protein isoforms where Gfapa is the most predominant isoform. The Gfapd isoform is expressed in proliferating......RNA localization patterns were dependent on the different 39-exon sequences included in Gfapd and Gfapa mRNA. The presented results show that alternative Gfap mRNA splicing results in isoform-specific mRNA localization patterns with resulting different local mRNA concentration ratios which have potential...

  1. Walk-off-induced modulation instability, temporal pattern formation, and frequency comb generation in cavity-enhanced second-harmonic generation

    CERN Document Server

    Leo, F; Ricciardi, I; De Rosa, M; Coen, S; Wabnitz, S; Erkintalo, M

    2016-01-01

    We derive a time-domain mean-field equation to model the full temporal and spectral dynamics of light in singly resonant cavity-enhanced second-harmonic generation systems. We show that the temporal walk-off between the fundamental and the second-harmonic fields plays a decisive role under realistic conditions, giving rise to rich, previously unidentified nonlinear behaviour. Through linear stability analysis and numerical simulations, we discover a new kind of quadratic modulation instability which leads to the formation of optical frequency combs and associated time-domain dissipative structures. Our numerical simulations show excellent agreement with recent experimental observations of frequency combs in quadratic nonlinear media [Phys. Rev. A 91, 063839 (2015)]. Thus, in addition to unveiling a new, experimentally accessible regime of nonlinear dynamics, our work enables predictive modeling of frequency comb generation in cavity-enhanced second-harmonic generation systems.

  2. A double burden of overall or central adiposity and anemia or iron deficiency is prevalent but with little socioeconomic patterning among Moroccan and Tunisian urban women.

    Science.gov (United States)

    Gartner, Agnès; El Ati, Jalila; Traissac, Pierre; Bour, Abdellatif; Berger, Jacques; Landais, Edwige; El Hsaïni, Houda; Ben Rayana, Chiheb; Delpeuch, Francis

    2014-01-01

    In North Africa, overnutrition has dramatically increased with the nutrition transition while micronutrient deficiencies persist, resulting in clustering of opposite types of malnutrition that can present a unique difficulty for public health interventions. We assessed the magnitude of the double burden of malnutrition among urban Moroccan and Tunisian women, as defined by the coexistence of overall or central adiposity and anemia or iron deficiency (ID), and explored the sociodemographic patterning of individual double burden. In cross-sectional surveys representative of the region around the capital city, we randomly selected 811 and 1689 nonpregnant women aged 20-49 y in Morocco and Tunisia, respectively. Four double burdens were analyzed: overweight (body mass index ≥25 kg/m(2)) or increased risk abdominal obesity (waist circumference ≥80 cm) and anemia (blood hemoglobin education groups. Generally, the rare, associated sociodemographic factors varied across the 4 subject-level double burdens and the 2 countries and differed from those usually associated with adiposity, anemia, or ID. Any double burden combining adiposity and anemia or ID should therefore be taken into consideration in all women. This trial was registered at clinicaltrials.gov as NCT01844349. PMID:24198310

  3. Conditions for Multi-functionality in a Rhythm Generating Network Inspired by Turtle Scratching

    OpenAIRE

    Snyder, Abigail C.; Rubin, Jonathan E

    2015-01-01

    Rhythmic behaviors such as breathing, walking, and scratching are vital to many species. Such behaviors can emerge from groups of neurons, called central pattern generators, in the absence of rhythmic inputs. In vertebrates, the identification of the cells that constitute the central pattern generator for particular rhythmic behaviors is difficult, and often, its existence has only been inferred. For example, under experimental conditions, intact turtles generate several rhythmic scratch moto...

  4. Neem leaf glycoprotein promotes dual generation of central and effector memory CD8(+) T cells against sarcoma antigen vaccine to induce protective anti-tumor immunity.

    Science.gov (United States)

    Ghosh, Sarbari; Sarkar, Madhurima; Ghosh, Tithi; Guha, Ipsita; Bhuniya, Avishek; Saha, Akata; Dasgupta, Shayani; Barik, Subhasis; Bose, Anamika; Baral, Rathindranath

    2016-03-01

    We have previously shown that Neem Leaf Glycoprotein (NLGP) mediates sustained tumor protection by activating host immune response. Now we report that adjuvant help from NLGP predominantly generates CD44(+)CD62L(high)CCR7(high) central memory (TCM; in lymph node) and CD44(+)CD62L(low)CCR7(low) effector memory (TEM; in spleen) CD8(+) T cells of Swiss mice after vaccination with sarcoma antigen (SarAg). Generated TCM and TEM participated either to replenish memory cell pool for sustained disease free states or in rapid tumor eradication respectively. TCM generated after SarAg+NLGP vaccination underwent significant proliferation and IL-2 secretion following SarAg re-stimulation. Furthermore, SarAg+NLGP vaccination helps in greater survival of the memory precursor effector cells at the peak of the effector response and their maintenance as mature memory cells, in comparison to single modality treatment. Such response is corroborated with the reduced phosphorylation of FOXO in the cytosol and increased KLF2 in the nucleus associated with enhanced CD62L, CCR7 expression of lymph node-resident CD8(+) T cells. However, spleen-resident CD8(+) T memory cells show superior efficacy for immediate memory-to-effector cell conversion. The data support in all aspects that SarAg+NLGP demonstrate superiority than SarAg vaccination alone that benefits the host by rapid effector functions whenever required, whereas, central-memory cells are thought to replenish the memory cell pool for ultimate sustained disease free survival till 60 days following post-vaccination tumor inoculation.

  5. A Simulation Experiment on a Built-In Self Test Equipped with Pseudorandom Test Pattern Generator and Multi-Input Shift Register (MISR

    Directory of Open Access Journals (Sweden)

    Afaq Ahmad

    2010-12-01

    Full Text Available This paper investigates the impact of the changes of the characteristic polynomials and initial loadings, on behaviour of aliasing errors of parallel signature analyzer (Multi-Input Shift Register, used in an LFSR based digital circuit testing technique. The investigation is carried-out through an extensive simulation study of the effectiveness of the LFSR based digital circuit testing technique. The results of the study show that when the identical characteristic polynomials of order n are used in both pseudo-random test-pattern generator, as well as in Multi-Input Shift Register (MISR signature analyzer (parallel type then the probability of aliasing errors remains unchanged due to the changes in the initial loadings of the pseudo-random test-pattern generator.

  6. Evidence of binary division in mature central capsules of a collosphaerid colonial radiolarian: Implications for shell ontogenetic patterns in modern and fossil species

    Digital Repository Service at National Institute of Oceanography (India)

    Anderson, O.R.; Gupta, S.M.

    of the skeletons are deposited at nearly the same time following multiple divisions of skeletonless central capsules and (2) "successive shell depositon," where mature central capsules with shells give rise to additional ones through delayed binary fission...

  7. Inertial-confinement fusion central-station electric-power-generating plant. Final report, March 1, 1979-September 30, 1980

    International Nuclear Information System (INIS)

    This report contains a complete description of the subsystems of the power plant including driver, driver power supply, pellet fabrication, pellet injection and aiming, data handling and control, evacuation, tritium and radwaste handling, first wall protection, first wall and structure, heat removal, tritium breeding and neutron shielding, maintenance and repair and balance of plant. In addition, it contains analytic support for the conceptual designs developed for each subsystem. The emphasis of the effort was on designing a viable reactor cavity and on solving the problems of interfacing the driver systems with the reactor cavity. The reactors generate 3500 NWt by irradiating a pellet whose gain is 175 from two opposite sides with a total of 2 MJ driver energy at a 10 Hz repetition rate. Because the nominal laser driver efficiency is 10% and that for the heavy ion driver is 30%, the net electric power outputs are 1207 MWe and 1346 MWe; the net plant conversion efficiencies are 28.1% and 31.3%; and the recirculating fractions are 22.9% and 14.0% respectively. The increased power output is, however, only one of the factors considered by utilities in performing a cost minimization analysis of competing power sources for system expansion. These other factors include: capital costs, cost of construction time, operating costs, environmental and licensing costs and reliability cost

  8. Inertial-confinement fusion central-station electric-power-generating plant. Final report, March 1, 1979-September 30, 1980

    International Nuclear Information System (INIS)

    This report contains a complete description of the subsystems of the power plant including driver, driver power supply, pellet fabrication, pellet injection and aiming, data handling and control, evacuation, tritium and radwaste handling, first wall protection, first wall and structure, heat removal, tritium breeding and neutron shielding, maintenance and repair and balance of plant. In addition, it contains analytic support for the conceptual designs developed for each subsystem. The emphasis of the effort was on designing a viable reactor cavity and on solving the problems of interfacing the driver systems with the reactor cavity. The reactors generate 3500 MWt by irradiating a pellet whose gain is 175 from two opposite sides with a total of 2 MJ driver energy at a 10 Hz repetition rate. Because the nominal laser driver efficiency is 10% and that for the heavy ion driver is 30%, the net electric power outputs are 1207 MWe and 1346 MWe; the net plant conversion efficiencies are 28.1% and 31.3%; and the recirculating fractions are 22.9% and 14.0% respectively. The increased power output is, however, only one of the factors considered by utilities in performing a cost minimization analysis of competing power sources for system expansion. These other factors include: capital costs, cost of construction time, operating costs, environmental and licensing costs and reliability cost

  9. Patterns of landscape form in the upper Rhône basin, Central Swiss Alps, predominantly show lithologic controls despite multiple glaciations and variations in rock uplift rates

    Science.gov (United States)

    Stutenbecker, L. A.; Costa, A.; Schlunegger, F.

    2015-10-01

    The development of topography is mainly dependent on the interplay of uplift and erosion, which are in term controlled by various factors including climate, glaciers, lithology, seismic activity and short-term variables such as anthropogenic impact. While most studies have focused on the role of tectonics and climate on the landscape form and underlying processes, less attention has been paid on exploring the controls of lithology on erosion. The Central European Alps are characterized by a large spatial variability in exposed lithologies and as such offer an ideal laboratory to investigate the lithological controls on erosion and landscape form. Here, we focus on the ca. 5400 km2-large upper Rhône basin situated in the Central Swiss Alps to explore how the lithological architecture of the bedrock conditions the Alpine landscape. To this extent, we extract geomorphological parameters along the channels of ca. 50 tributary basins, whose catchments are located in either granitic basement rocks (External massifs), oceanic meta-sedimentary and ophiolitic rocks (Penninic nappes) or fine-grained continental-margin sediments (Helvetic nappes). The analysis of longitudinal river profiles show that all tributary rivers within the Rhône basin are in topographic transient state as testified by mainly convex or concave-convex longitudinal stream channel profiles with several knickpoints of either tectonic or glacial origin. In addition, although the entire Rhône basin shows a strong glacial inheritance (and is still partly glaciated) and some of the highest uplift rates recently measured in the Alps, the river network has responded differently to those perturbations as revealed by the morphometric data. In particular, tributary basins in the Helvetic nappes are the most equilibrated (concave river profiles, overall lower elevations, less steep slope gradients and lowest hypsometric integrals), while the tributaries located in the External massifs are least equilibrated

  10. Changes in the pattern of distribution of von Willebrand factor in rat aortic endothelial cells following thrombin generation in vivo.

    Science.gov (United States)

    Senis, Y A; Richardson, M; Tinlin, S; Maurice, D H; Giles, A R

    1996-04-01

    The pattern of distribution of von Willebrand factor (VWF) in relatively large sheets of rat aortic endothelial cells (EC) obtained by the Häutchen technique were analysed by immunocytochemistry and light microscopy. EC were examined pre and post administration of a procoagulant mixture of factor Xa (F.Xa) and phosphotidylcholine/phosphotidylserine (PCPS) vesicles which was demonstrated to result in the selective loss of high molecular weight multimers (HMWM) of plasma VWF in the rat. In placebo animals the pattern was heterogenous both in overall distribution and in individual cells which showed both a diffuse and granular pattern. Groups of intensely stained EC were oriented parallel to the longitudinal axis of the aorta and staining was particularly prominent around the orifices of the intercostal arteries, implicating shear-stress as a possible factor in VWF expression by EC. Changes in the pattern of distribution of staining were observed at various time points post-infusion of F.Xa/PCPS, suggesting the immediate release of VWF from EC stores followed by the recruitment of EC to synthesize and store VWF. These changes are consistent with the decrease in EC Weibel-Palade Body (WPB) content observed by EM in previously reported studies using this model. PMID:8611460

  11. Role of dietary patterns, sedentary behaviour and overweight of the longditudinal development of childhood constipation: The generation R Study

    NARCIS (Netherlands)

    Kiefte-de Jong, J.C.; Vries, de J.H.M.; Escher, J.; Jaddoe, V.W.; Hofman, M.K.; Raat, H.; Moll, H.

    2013-01-01

    The influence of childhood nutrition on the development of constipation beyond the period of weaning and breastfeeding is relatively understudied. In addition, eating patterns in childhood can be highly correlated with overweight and sedentary behaviour, which may also have an influence on constipat

  12. Reducing False Alarms of Annual Forecast in the Central China North-South Seismic Belt by Reverse Tracing of Precursors (RTP) Using the Pattern Informatics (PI) `Hotspots'

    Science.gov (United States)

    Zhang, Shengfeng; Wu, Zhongliang; Jiang, Changsheng

    2016-05-01

    The annual consultation on the likelihood of earthquakes in the next year, the `Annual Consultation Meeting', has been one of the most important forward forecast experiments organized by the China Earthquake Administration (CEA) since the 1970s, in which annual alarm regions are identified by an expert panel considering multi-disciplinary `anomalies'. In such annual forecasts, one of the problems in need of further technical solution is its false alarms. To tackle this problem, the concept of `reverse tracing of precursors (RTP)' is used to the annual consultation, as a temporal continuation and spatial extension of the work of Zuc(hao) et al. (Pure Appl Geophys 167:783-800, 2010). The central China north-south seismic belt (in connection to the CSEP testing region) is selected as the testing region of such an approach. Applying the concept of RTP, for an annual alarm region delineated by the Annual Consultation Meeting, the distribution of `hotspots' of the pattern informatics (PI), which targets the 5-year-scale seismic hazard, is considered. The `hit', or successful forecast, of the annual seismic hazard is shown to be related to the sufficient coverage of the `hotspots' within the annual alarm region. The ratio of the areas of the `hotspots' over the whole area of the annual alarm region is thus used to identify the false alarms which have few `hotspots'. The results of the years 2004-2012 show that using a threshold of 17 % can reduce 34 % (13 among 38) of the false alarms without losing the successful hit (being 6 in that period).

  13. A prospective study of magnetic resonance imaging patterns of central nervous system infections in pediatric age group and young adults and their clinico-biochemical correlation

    Directory of Open Access Journals (Sweden)

    Kamini Gupta

    2016-01-01

    Full Text Available Background: Infections of the central nervous system (CNS are common and routinely encountered. Our aim was to evaluate the neuroimaging features of the various infections of the CNS so as to differentiate them from tumoral, vascular, and other entities that warrant a different line of therapy. Aims: Our aim was to analyze the biochemical and magnetic resonance imaging (MRI features in CNS infections. Settings and Design: This was a longitudinal, prospective study over a period of 1½ years. Subjects and Methods: We studied cerebrospinal fluid (CSF findings and MRI patterns in 27 patients of 0–20 years age group with clinical features of CNS infections. MRI was performed on MAGNETOM Avanto 18 Channel 1.5 Tesla MR machine by Siemens India Ltd. The MRI protocol consisted of diffusion-weighted and apparent diffusion coefficient imaging, turbo spin echo T2-weighted, spin echo T1-weighted, fluid-attenuated inversion recovery (FLAIR, and gradient-echo in axial, FLAIR in coronal, and T2-weighted in sagittal plane. Contrast-enhanced T1-weighted sequence and MR spectroscopy were done whenever indicated. Results and Conclusions: We found that most of the children belong to 1–10 years age group. Fungal infections were uncommon, mean CSF adenosine deaminase values specific for tuberculosis and mean CSF glucose-lowered in pyogenic. Hemorrhagic involvement of thalamus with/without basal ganglia and brainstem involvement may indicate Japanese encephalitis or dengue encephalitis. Diffusion restriction or hemorrhage in not expected in the brainstem afflicted lesions of rabies. Congenital cytomegalovirus can cause cortical malformations. T1 hyperintensities with diffusion restriction may represent viral encephalitis. Lesions of acute disseminated encephalomyelitis (ADEM may mimic viral encephalitis. Leptomeningeal enhancement is predominant in pyogenic meningitis. Basilar meningitis in the presence of tuberculomas is highly sensitive and specific for

  14. Applications of seismic pattern recognition and gravity inversion techniques to obtain enhanced subsurface images of the Earth's crust under the Central Metasedimentary Belt, Grenville Province, Ontario

    Science.gov (United States)

    Roy, Baishali; Mereu, R. F.

    2000-12-01

    Project Lithoprobe's Abitibi-Grenville transect seismic reflection lines 32 and 33 traverse the exposed Central Metasedimentary Belt (CMB) located in the Grenville province of the Precambrian Shield of Canada in southern Ontario. These seismic lines image a zone with a protracted deformational history spanning more than 300Myr. Detailed examination of the commercially processed stacked sections reveals a number of significant deficiencies in some important areas. The image quality in these zones of reduced coherency needs to be enhanced to examine specific features and their relation to the surface geology. Examination of near-vertical seismic data from Lines 32 and 33 revealed that the signal-to-noise ratio was not improved by stacking, due to misalignment of signals even after static, normal moveout corrections and residual static corrections. The presumed reason is that reflected seismic energy following long ray paths in heterogeneous media suffers from relative advances and delays in its propagation, and hence arrives at slightly different times at the receivers, tending to be poorly aligned relative to its theoretical traveltime curves. A pattern recognition (PR) method for signal enhancement followed by energy stacking in moving time windows was used in this study to improve the images in spite of misalignments. Reprocessing has refined the geometry of the reflection profiles. The objective of this paper is to use enhanced images of the seismic reflection data obtained by using a PR approach together with gravity data, using 2.5-D forward and 3-D inversion routines, to give an improved model of subsurface structure in the vicinity of lines 32 and 33. Line 32 is dominated by southeast-dipping reflectors soling into the lower crust. The listric geometry of the strong reflection packages of the CMB boundary thrust zone is interpreted to represent a crustal-scale ramp-flat geometry that accommodated northwest-directed tectonic transport of the CMB. This

  15. Use of adaptive network burst detection methods for multielectrode array data and the generation of artificial spike patterns for method evaluation

    Science.gov (United States)

    Mendis, G. D. C.; Morrisroe, E.; Petrou, S.; Halgamuge, S. K.

    2016-04-01

    Objective. Multielectrode arrays are an informative extracellular recording technology that enables the analysis of cultured neuronal networks and network bursts (NBs) are a dominant feature observed in these recordings. This paper focuses on the validation of NB detection methods on different network activity patterns and developing a detection method that performs robustly across a wide variety of activity patterns. Approach. A firing rate based approach was used to generate artificial spike timestamps where NBs were introduced as episodes where the probability of spiking increases. Variations in firing and bursting characteristics were also included. In addition, an improved methodology of detecting NBs is proposed, based on time-binned average firing rates and time overlaps of single channel bursts. The robustness of the proposed method was compared against three existing algorithms using simulated, publicly available and newly acquired data. Main results. A range of activity patterns were generated by changing simulation variables that correspond to NB duration (40-2200 ms), intervals (0.3-16 s), firing rates (0.1-1 spikes s-1), local burst percentage (0%-90%), number of channels in local bursts (20-40) as well as the number of tonic and frequently-bursting channels. By extracting simulation parameters directly from real data, we generated synthetic data that closely resemble activity of mouse and rat cortical cultures at native and chemically perturbed states. In 50 simulated data sets with randomly selected parameter values, the improved NB detection method performed better (ascertained by the f-measure) than three existing methods (p neuronal activity patterns. Furthermore, it proposes an improved NB detection method that can be used robustly across a range of data types.

  16. Soil cover patterns influence on the land environmental functions, agroecological quality, land-use and monitoring efficiency in the Central Russia

    Science.gov (United States)

    Vasenev, Ivan; Yashin, Ivan; Lukin, Sergey; Valentini, Riccardo

    2015-04-01

    First decades of XXI century actualized for soil researches the principal methodical problem of most modern geosciences: what spatial and temporal scale would be optimal for land quality evaluation and land-use practice optimizing? It is becoming obvious that this question cannot have one solution and have to be solved with especial attention on the features of concrete region and landscape, land-use history and practical issues, land current state and environmental functions, soil cover patterns and variability, governmental requirements and local society needs, best available technologies and their potential profitability. Central Russia is one of the most dynamical economic regions with naturally high and man-made complicated landscape and soil cover variability, long-term land-use history and self-contradictory issues, high potential of profitable farming and increased risks of land degradation. Global climate and technological changes essentially complicate the originally high and sharply increased in XX century farming land heterogeneity in the Central Russia that actualizes system analysis of its zonal, intra-zonal and azonal soil cover patterns according to their influence on land environmental functions, agroecological quality, and land-use and monitoring efficiency variability. Developed by the Laboratory of agroecological monitoring, ecosystem modeling & prediction (LAMP / RTSAU with support of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) regional systems of greenhouse gases environmental monitoring RusFluxNet (6 fixed & 1 mobile eddy covariance stations with zonal functional sets of key plots with chamber investigations in 5 Russian regions) and of agroecological monitoring (in representative key plots with different farming practice in 9 RF regions) allow to do this analysis in frame of enough representative regional multi-factorial matrix of soil cover patterns, bioclimatic conditions, landscape features, and land-use history and

  17. Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity in California and the Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Wiser, Ryan H; Wiser, Ryan H; Fripp, Matthias

    2008-05-01

    Wind power production is variable, but also has diurnal and seasonal patterns. These patterns differ between sites, potentially making electric power from some wind sites more valuable for meeting customer loads or selling in wholesale power markets. This paper investigates whether the timing of wind significantly affects the value of electricity from sites in California and the Northwestern United States. We use both measured and modeled wind data and estimate the time-varying value of wind power with both financial and load-based metrics. We find that the potential difference in wholesale market value between better-correlated and poorly correlated wind sites is modest, on the order of 5-10 percent. A load-based metric, power production during the top 10 percent of peak load hours, varies more strongly between sites, suggesting that the capacity value of different wind projects could vary by as much as 50 percent based on the timing of wind alone.

  18. Sparse approaches for the exact distribution of patterns in long multi-states sequences generated by a Markov source

    CERN Document Server

    Nuel, Grégory

    2010-01-01

    We present two novel approaches for the computation of the exact distribution of a pattern in a long sequence. Both approaches take into account the sparse structure of the problem. The first approach relies on a partial recursion computing the largest eigenvalue of the the transition matrix of a Markov chain embedding. The second approach uses fast Taylor expansions of an exact bivariate rational reconstruction of the distribution. We illustrate the interest of both approaches on a simple toy-example and two biological applications: the transcription factors of the Human Chromosome 5 and the PROSITE signatures of functional motifs in proteins. On these examples our methods demonstrate their complementarity and their hability to extend the domain of feasibility for exact computations in pattern problems to a new level.

  19. Non-neutralized Electric Current Patterns in Solar Active Regions: Origin of the Shear-Generating Lorentz Force

    CERN Document Server

    Georgoulis, Manolis K; Mikic, Zoran

    2012-01-01

    Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio we perform a detailed study of electric current patterns in two solar active regions: a flaring/eruptive, and a flare-quiet one. We aim to determine whether active regions inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within active regions are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most active regions appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated active regions re...

  20. Automatic Locomotion Generation for a UBot Modular Robot – Towards Both High-speed and Multiple Patterns

    Directory of Open Access Journals (Sweden)

    Jie Zhao

    2015-04-01

    Full Text Available Modular self-reconfigurable robots (SRRs have redundant degrees of freedom and various configurations. There are two hard problems imposed by SRR features: locomotion planning and the discovery of multiple locomotion patterns. Most of the current research focuses on solving the first problem, using evolutionary algorithms based on the philosophy of searching-for-the-best. The main problem is that the search can fall into a local optimum in the case of a complex non-linear problem. Another drawback is that the searched result lacks diversity in the behaviour space, which is inappropriate in addressing the problem of discovering multiple locomotion patterns. In this paper, we present a new strategy that evolves an SRR’s controller by searching for behavioural diversity. Instead of converging on a single optimal solution, this strategy discovers a vast variety of different ways to realize robot locomotion. Optimal motion is sparse in the behaviour space, and this method can find it as a by-product through a diversity-keeping mechanism. A revised particle swarm optimization (PSO algorithm, driven by behaviour sparseness, is implemented to evolve locomotion for a variety of configurations whose efficiency and flexibility is validated. The results show that this method can not only obtain an optimized robot controller, but also find various locomotion patterns.

  1. NOX4 activity is determined by mRNA levels and reveals a unique pattern of ROS generation

    OpenAIRE

    Serrander, Lena; Cartier, Laetitia; Bedard, Karen; Banfi, Botond; Lardy, Bernard; Plastre, Olivier; Sienkiewicz, Andrzej; Fórró, Laszló; Schlegel, Werner; Krause, Karl-Heinz

    2007-01-01

    Abstract NOX4 is an enigmatic member of the NOX family of ROS-generating NADPH oxidases. NOX4 has a wide tissue distribution, but the physiological function and activation mechanisms are largely unknown, and its pharmacology poorly understood. We have generated cell lines expressing NOX4 upon tetracycline induction. Tetracycline induced a rapid increase in NOX4 mRNA (1h) followed closely (2h) by a release of reactive oxygen species (ROS). Upon tetracycline withdrawal, NOX4 mRNA lev...

  2. SJL mice infected with Acanthamoeba castellanii develop central nervous system autoimmunity through the generation of cross-reactive T cells for myelin antigens.

    Science.gov (United States)

    Massilamany, Chandirasegaran; Marciano-Cabral, Francine; Rocha-Azevedo, Bruno da; Jamerson, Melissa; Gangaplara, Arunakumar; Steffen, David; Zabad, Rana; Illes, Zsolt; Sobel, Raymond A; Reddy, Jay

    2014-01-01

    We recently reported that Acanthamoeba castellanii (ACA), an opportunistic pathogen of the central nervous system (CNS) possesses mimicry epitopes for proteolipid protein (PLP) 139-151 and myelin basic protein 89-101, and that the epitopes induce experimental autoimmune encephalomyelitis (EAE) in SJL mice reminiscent of the diseases induced with their corresponding cognate peptides. We now demonstrate that mice infected with ACA also show the generation of cross-reactive T cells, predominantly for PLP 139-151, as evaluated by T cell proliferation and IAs/dextramer staining. We verified that PLP 139-151-sensitized lymphocytes generated in infected mice contained a high proportion of T helper 1 cytokine-producing cells, and they can transfer disease to naïve animals. Likewise, the animals first primed with suboptimal dose of PLP 139-151 and later infected with ACA, developed EAE, suggesting that ACA infection can trigger CNS autoimmunity in the presence of preexisting repertoire of autoreactive T cells. Taken together, the data provide novel insights into the pathogenesis of Acanthamoeba infections, and the potential role of infectious agents with mimicry epitopes to self-antigens in the pathogenesis of CNS diseases such as multiple sclerosis.

  3. Impact of Thermal Plumes Generated by Occupant Simulators with Different Complexity of Body Geometry on Airflow Pattern in Rooms

    DEFF Research Database (Denmark)

    Zukowska, Daria; Melikov, Arsen Krikor; Popiolek, Zbigniew

    2008-01-01

    manikins resembling accurately human body shape and then by two heated cylinders. The manikins and the cylinders had the same surface area of 1.63 m2 and the same heat generation of 73 W. CO2 supplied from the top of the heat sources was used for simulating bio-effluents. CO2 concentration was measured...

  4. Conventional and intelligent generalized supervisory control for combined cycle generating power stations.; Control supervisiorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, Miguel A; Sanchez P, Marino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gonzalez Rubio S, Jose L [Cento Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

    2005-07-01

    Under the expectations of expansion of electric power generation in Mexico, this work exposes the development of a conventional and intelligent generalized supervisory control (CSG) for a combined cycle generation power plant. This one allows to obtain the optimal operation of the power plant through the automatic starting of the generating units and to obtain the maximum possible amount of electrical power in automatic and safe form. For the development of the CSG a control loop by temperature was implemented for the gas turbine system and a control loop by strangled pressure for the gas turbine and a control loop by strangled pressure for the steam turbine. The design of these supervisory systems was made with base in the critical limits on the involved variables of the process: blading average temperature, for the gas turbine (GT) and strangled pressure for the steam turbine (ST) [Spanish] Bajo estas expectativas de expansion de generacion de energia en Mexico, este trabajo expone el desarrollo de un control supervisorio generalizado (CSG) para una central generacion de ciclo combinado. Este permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas y un lazo de control por presion estrangulada para la turbina de gas y un lazo de control por presion estrangulada para la turbina de vapor. El diseno de estos sistemas supervisorio se realizo con base en los limites criticos de las variables del proceso involucradas: temperatura promedio de empaletado para la turbina de gas (TG) y presion estrangulada para la turbina de vapor (TV)

  5. Incidence Patterns and Trends of non-Central Nervous System Solid Tumours in Children and Adolescents. A Collaborative Study of the Spanish Population Based Cancer Registries

    Science.gov (United States)

    Larrañaga, Nerea; Sanchez, Mª José; Ardanaz, Eva; Felipe, Saray; Marcos-Gragera, Rafael; Ramos, María; Carulla, Marià; Chirlaque, Mª Dolores; Argüelles, Marcial V.; Martos, Carmen; Mateo, Antonio; Peris-Bonet, Rafael

    2016-01-01

    Objective: To describe incidence patterns and trends in children (0-14 years) and adolescents (15-19 age-range) with solid tumours, except those of central nervous system (CNS), in Spain. Methods: Cases were drawn from eleven Spanish population-based cancer registries. Incidence was estimated for the period 1983-2007 and trends were evaluated using Joinpoint regression analysis. Results: The studied tumour groups accounted for 36% of total childhood cancers and 47.6% of those diagnosed in adolescence with annual rates per million of 53.5 and 89.3 respectively. In children 0 to 14 years of age, Neuroblastoma (NB) was the commonest (7.8%) followed by Soft-tissue sarcomas (STS) (6.3%), bone tumours (BT) (6.2%) and renal tumours (RT) (4.5%). NB was the most frequently diagnosed tumour before the 5th birthday, while STS and BT were the commonest at 5-9 years of age, and BT and Carcinoma and other epithelial tumours (COET) at 10-14. COET presented the highest incidence in adolescents, followed by germ-cell tumours (GCT), BT and STS. These four diagnostic groups accounted for 94% of total non-CNS solid tumours, in adolescents. Overall incidence rates increased significantly in children up to 1996 with an annual percentage change (APC) of 2.6% (95%CI: 1.7; 3.6). NB and COET showed significant time trend (APCs: 1.4% and 3.8% respectively) while other tumour groups such as RT, STS, BT or GCT had no significant changes over time. A significant increase was present in NB under the age of 5 and in BT and STS in children aged 10-14 years. In adolescents there were significant increases for all tumours combined (APC=2.7; 95%CI: 1.8-3.6) and for STS, GCT and COET (APCs: 3.2%, 4.4% and 3.5% respectively), while other tumour groups such as hepatic tumours, BT or thyroid carcinomas showed a decreasing trend or no increase. Conclusions: Overall, the incidence of the studied cancers in children increased along the period 1983-1996 with no posterior significant rise, while the incidence

  6. Sequencing of Local Therapy Affects the Pattern of Treatment Failure and Survival in Children With Atypical Teratoid Rhabdoid Tumors of the Central Nervous System

    International Nuclear Information System (INIS)

    Purpose: To assess the pattern of treatment failure associated with current therapeutic paradigms for childhood atypical teratoid rhabdoid tumors (AT/RT). Methods and Materials: Pediatric patients with AT/RT of the central nervous system treated at our institution between 1987 and 2007 were retrospectively evaluated. Overall survival (OS), progression-free survival, and cumulative incidence of local failure were correlated with age, sex, tumor location, extent of disease, and extent of surgical resection. Radiotherapy (RT) sequencing, chemotherapy, dose, timing, and volume administered after resection were also evaluated. Results: Thirty-one patients at a median age of 2.3 years at diagnosis (range, 0.45–16.87 years) were enrolled into protocols that included risk- and age-stratified RT. Craniospinal irradiation with focal tumor bed boost (median dose, 54 Gy) was administered to 18 patients. Gross total resection was achieved in 16. Ten patients presented with metastases at diagnosis. RT was delayed more than 3 months in 20 patients and between 1 and 3 months in 4; 7 patients received immediate postoperative irradiation preceding high-dose alkylator-based chemotherapy. At a median follow-up of 48 months, the cumulative incidence of local treatment failure was 37.5% ± 9%; progression-free survival was 33.2% ± 10%; and OS was 53.5% ± 10%. Children receiving delayed RT (≥1 month postoperatively) were more likely to experience local failure (hazard ratio [HR] 1.23, p = 0.007); the development of distant metastases before RT increased the risk of progression (HR 3.49, p = 0.006); and any evidence of disease progressionbefore RT decreased OS (HR 20.78, p = 0.004). Disease progression occurred in 52% (11/21) of children with initially localized tumors who underwent gross total resection, and the progression rate increased proportionally with increasing delay from surgery to RT. Conclusions: Delayed RT is associated with a higher rate of local and metastatic disease

  7. Sequencing of Local Therapy Affects the Pattern of Treatment Failure and Survival in Children With Atypical Teratoid Rhabdoid Tumors of the Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    Pai Panandiker, Atmaram S., E-mail: atmaram.pai-panandiker@stjude.org [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Merchant, Thomas E.; Beltran, Chris [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Wu, Shengjie [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, TN (United States); Sharma, Shelly [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Boop, Frederick A. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, TN (United States); Jenkins, Jesse J. [Department of Pathology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Helton, Kathleen J. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Wright, Karen D.; Broniscer, Alberto [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Kun, Larry E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, TN (United States); Gajjar, Amar [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States)

    2012-04-01

    Purpose: To assess the pattern of treatment failure associated with current therapeutic paradigms for childhood atypical teratoid rhabdoid tumors (AT/RT). Methods and Materials: Pediatric patients with AT/RT of the central nervous system treated at our institution between 1987 and 2007 were retrospectively evaluated. Overall survival (OS), progression-free survival, and cumulative incidence of local failure were correlated with age, sex, tumor location, extent of disease, and extent of surgical resection. Radiotherapy (RT) sequencing, chemotherapy, dose, timing, and volume administered after resection were also evaluated. Results: Thirty-one patients at a median age of 2.3 years at diagnosis (range, 0.45-16.87 years) were enrolled into protocols that included risk- and age-stratified RT. Craniospinal irradiation with focal tumor bed boost (median dose, 54 Gy) was administered to 18 patients. Gross total resection was achieved in 16. Ten patients presented with metastases at diagnosis. RT was delayed more than 3 months in 20 patients and between 1 and 3 months in 4; 7 patients received immediate postoperative irradiation preceding high-dose alkylator-based chemotherapy. At a median follow-up of 48 months, the cumulative incidence of local treatment failure was 37.5% {+-} 9%; progression-free survival was 33.2% {+-} 10%; and OS was 53.5% {+-} 10%. Children receiving delayed RT ({>=}1 month postoperatively) were more likely to experience local failure (hazard ratio [HR] 1.23, p = 0.007); the development of distant metastases before RT increased the risk of progression (HR 3.49, p = 0.006); and any evidence of disease progressionbefore RT decreased OS (HR 20.78, p = 0.004). Disease progression occurred in 52% (11/21) of children with initially localized tumors who underwent gross total resection, and the progression rate increased proportionally with increasing delay from surgery to RT. Conclusions: Delayed RT is associated with a higher rate of local and metastatic

  8. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching

    OpenAIRE

    Chinta Someswara Rao; Viswanadha Raju, S.

    2016-01-01

    Next generation sequencing (NGS) technologies have been rapidly applied in biomedical and biological research in recent years. To provide the comprehensive NGS resource for the research, in this paper , we have considered 10 loci/codi/repeats TAGA, TCAT, GAAT, AGAT, AGAA, GATA, TATC, CTTT, TCTG and TCTA. Then we developed the NGS Tandem Repeat Database (TandemRepeatDB) for all the chromosomes of Homo sapiens, Callithrix jacchus, Chlorocebus sabaeus, Gorilla gorilla, Macaca fascicularis, Macac...

  9. Generalized conventional and intelligent supervisory control system for combined cycle generation power plants; Sistema de control supervisorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Morales, Miguel Angel

    2004-12-15

    (conventional or intelligent) is possible to get more power generation than if we use the automatic methods based on feedback MW control. Consequently, the financial benefit due to the MW generated along a period of 2 months, is equivalent to return the investment required if the CCPP would had been repowered. Test also showed that with the fuzzy based SGC is possible to get a 'little more' power generation than if we use the PID based SGC. The development and implementation of the SGC was made in three phases: First Phase: Upgrading of the simulation dynamic mathematical model and implementation in a new software platform based on LabWindows/CVI. Second Phase: Design, implementation and testing of the PID based SGC. Third Phase: Design and implementation and testing of the Intelligent SGC, based in fuzzy logic. [Spanish] El programa de obras de generacion de la Comision Federal de Electricidad (CFE) del ano 2004 al ano 2008 esta caracterizado por el dominio del proceso de ciclo combinado para la expansion de generacion de energia en Mexico [CFE, 2000]. De acuerdo con los datos presentados por esta fuente, el incremento estimado en la capacidad de generacion de potencia electrica es de 12876 MW, de los cuales las centrales de ciclo combinado aportaran 10655 MW, lo que representa el 82.75%. Bajo estas expectativas de expansion de generacion de energia en Mexico, en este trabajo de tesis se desarrollo un sistema de control supervisorio generalizado (CSG) convencional (PID) e inteligente (logica difusa) para una central de generacion de ciclo combinado, el cual permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas (TG) y un lazo de control por presion estrangulada para la turbina de vapor (TV). El diseno de estos sistemas

  10. Generation and fate of glacial sediments in the central Transantarctic Mountains based on radiogenic isotopes and implications for reconstructing past ice dynamics

    Science.gov (United States)

    Farmer, G. Lang; Licht, Kathy J.

    2016-10-01

    The Nd, Sr and Pb isotopic compositions of glacial tills from the Byrd and Nimrod Glaciers in the central Transantarctic Mountains (TAM) in East Antarctica were obtained to assess the sources of detritus transported by these ice masses. Tills from lateral moraines along the entire extent of both glaciers have isotopic compositions consistent with their derivation predominately from erosion of adjacent bedrock. Fine- (<63μ) and coarser-grained (0.5 mm-2 mm) sediment from these tills have identical isotopic characteristics, indicating that fine-grained detritus is the product of further comminution of coarser sediments. Comparison of present-day till isotopic data to existing data from fine-grained LGM tills in the central Ross Sea confirm that these were deposited from East Antarctic ice that expanded through the TAM and indicates that the LGM sediments are mixtures of detritus eroded along the entire path of ice transiting the TAM. If specific lithologies were preferentially eroded as ice passed through the TAM, it is not clearly evident in the Ross Sea till isotopic compositions. Our data do demonstrate, however, that glacial tills generated from erosion of inboard regions of the mountain belt yield sediment with a larger component of 560 Ma to 600 Ma detrital zircons and lower average εNd(0) values (<-5) than that produced further downstream. As a result, past retreat of ice grounding-lines up the narrow valleys of the TAM resulting in active erosion of inboard region should recognizable in glacial sediments deposited in the Ross Sea and so provide a means to identify times when the East Antarctic ice sheet was smaller than today. This study highlights both the value and necessity of utilizing multiple provenance methods in evaluating glacial erosion and transport when reconstructing past ice sheet dynamics.

  11. On Centralized Fuel Purchasing of Power Generating Utilities%试论发电集团燃料的集中采购

    Institute of Scientific and Technical Information of China (English)

    李飞

    2014-01-01

    由于煤碳资源限制、交通运输制约和供需格局不均衡等原因,使得发电集团的燃料采购长期实行分散采购模式。这种模式存在着管控力度弱、短期行为多,采购范围小,成本高,且不利监督约制等一系列的问题。随着市场经济的发展,外部市场给集中采购营造了良好的环境,而且集中采购可以整合采购资源,降低成本,也有利于加强集团管控力度,规范采购行为,因此,实行集中采购是必要的也是可行的。%Due to the resource control of coal, limitation of transportation and uneven supply-demand distribu-tion, etc., power generating utilities have been practicing separate purchasing for long time.This mode has defi-ciency in terms of weak control, many short-term behaviors, small purchase scope, high cost and inconvenience of monitoring.As the market economy develops, external market provides a good environment for centralized purcha-sing, which can integrate resources, lower costs, enhance management and regulate purchasing behaviors.Thus it is imperative to implement centralized purchasing.

  12. Neutrophil Extracellular Traps Identification in Tegumentary Lesions of Patients with Paracoccidioidomycosis and Different Patterns of NETs Generation In Vitro.

    Directory of Open Access Journals (Sweden)

    Amanda Manoel Della Coletta

    Full Text Available Paracoccidioidomycosis (PCM is a systemic mycosis, endemic in most Latin American countries, especially in Brazil. It is caused by the thermo-dimorphic fungus of the genus Paracoccidioides (Paracoccidioides brasiliensis and Paracoccidioides lutzii. Innate immune response plays a crucial role in host defense against fungal infections, and neutrophils (PMNs are able to combat microorganisms with three different mechanisms: phagocytosis, secretion of granular proteins, which have antimicrobial properties, and the most recent described mechanism called NETosis. This new process is characterized by the release of net-like structures called Neutrophil Extracellular Traps (NETs, which is composed of nuclear (decondensed DNA and histones and granular material such as elastase. Several microorganisms have the ability of inducing NETs formation, including gram-positive and gram-negative bacteria, viruses and some fungi. We proposed to identify NETs in tegumentary lesions of patients with PCM and to analyze the interaction between two strains of P. brasiliensis and human PMNs by NETs formation in vitro. In this context, the presence of NETs in vivo was evidenced in tegumentary lesions of patients with PCM by confocal spectrum analyzer. Furthermore, we showed that the high virulent P. brasiliensis strain 18 (Pb18 and the lower virulent strain Pb265 are able to induce different patterns of NETs formation in vitro. The quantification of extracellular DNA corroborates the idea of the ability of P. brasiliensis in inducing NETs release. In conclusion, our data show for the first time the identification of NETs in lesions of patients with PCM and demonstrate distinct patterns of NETs in cultures challenged with fungi in vitro. The presence of NETs components both in vivo and in vitro open new possibilities for the detailed investigation of immunity in PCM.

  13. Discovery of a Metal-Poor Field Giant with a Globular Cluster Second-Generation Abundance Pattern

    CERN Document Server

    Fernandez-Trincado, J G; Moreno, E; Schiavon, R P; Peréz, A E García; Vieira, K; Cunha, K; Zamora, O; Sneden, C; Carrera, R; Johnson, J A; Shetrone, M; Zasowski, G; García-Hernándes, D A; Majewski, S R; Reylé, C; Blanco-Cuaresma, S; Martinez-Medina, L A; Pérez-Villegas, A; Valenzuela, O; Pichardo, B; Meza, A; Mészáros, Sz; Sobeck, J; Geisler, D; Anders, F; Schultheis, M; Tang, B; Roman-Lopes, A; Mennickent, R E; Pan, K; Nitschelm, C; Allard, F

    2016-01-01

    We report on the direct detection from observations obtained with the APOGEE survey of a metal-poor ([Fe/H]$=-1.3$) field giant star in the Milky Way, with an extreme Mg-Al abundance ([Mg/Fe]$=$-0.31; [Al/Fe]$=$1.49) seen only among the secondary population of globular clusters. This star, 2M16011638-1201525 found using SDSSIII/APOGEE data also shows particularly atypical light-element patterns not seen among Galactic disk field stars, indicating that it could have been born in a globular cluster. We explore several explanations, in particular studying the orbit of the star to check the probability of it being related to known globular clusters. With the use of a Monte Carlo scheme, we performed simple orbital integrations assuming the estimated distance of 2M16011638-1201525 and the available six-dimensional phase-space coordinates of 63 globular clusters, looking for close encounters in the past with a minimum distance approach within the tidal radius for each cluster. We found a very low probability that 2...

  14. Effect of the electric field pattern on the generation of fast electrons in front of lower hybrid launchers

    Energy Technology Data Exchange (ETDEWEB)

    Valade, Laurent, E-mail: laurent.valade@cea.fr; Ekedahl, Annika; Colas, Laurent; Goniche, Marc; Hillairet, Julien [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); Fuchs, Vladimir; Petrzilka, Vaclav [Institute of Plasma Physics, AS CR, Prague (Czech Republic); Li, Miaohui; Zhang, Bin [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-12-10

    The effect of the detailed waveguide spectrum on the electron acceleration has been studied for the 3.7 GHz LHCD launchers in Tore Supra, i.e. the ITER-like passive-active multijunction (PAM) launcher and the fully-active-multijunction (FAM) launcher, using test electron modelling technique. The detailed launched antenna wave spectrum is used as input to the code that computes the dynamics of the electrons in the electric field. Comparison with the LHCD launchers in EAST, operating at 2.45 GHz and 4.6 GHz, has also been made. The simulations show that the PAM-design generates lower flux of fast electrons than FAM-launchers, this could be the consequence of the wider waveguide of PAM-launcher (14.65 mm for Tore-Supra) than FAM-launcher (8 mm for Tore-Supra)

  15. Experimental studies of vertical mixing patterns in open channel flow generated by two delta wings side-by-side

    Science.gov (United States)

    Vaughan, Garrett

    Open channel raceway bioreactors are a low-cost system used to grow algae for biofuel production. Microalgae have many promises when it comes to renewable energy applications, but many economic hurdles must be overcome to achieve an economic fuel source that is competitive with petroleum-based fuels. One way to make algae more competitive is to improve vertical mixing in algae raceway bioreactors. Previous studies show that mixing may be increased by the addition of mechanisms such as airfoils. The circulation created helps move the algae from the bottom to top surface for necessary photosynthetic exchange. This improvement in light utilization allowed a certain study to achieve 2.2-2.4 times the amount of biomass relative to bioreactors without airfoils. This idea of increasing mixing in open channel raceways has been the focus of the Utah State University (USU) raceway hydraulics group. Computational Fluid Dynamics (CFD), Acoustic Doppler Velocimetry (ADV), and Particle Image Velocimetry (PIV) are all methods used at USU to computationally and experimentally quantify mixing in an open channel raceway. They have also been used to observe the effects of using delta wings (DW) in increasing vertical mixing in the raceway. These efforts showed great potential in the DW in increasing vertical mixing in the open channel bioreactor. However, this research begged the question, does the DW help increase algae growth? Three algae growth experiments comparing growth in a raceway with and without DW were completed. These experiments were successful, yielding an average 27.1% increase in the biomass. The DW appears to be a promising method of increasing algae biomass production. The next important step was to quantify vertical mixing and understand flow patterns due to two DWs side-by-side. Raceway channels are wider as they increase in size; and arrays of DWs will need to be installed to achieve quality mixing throughout the bioreactor. Quality mixing was attained for

  16. Permission of change of limits in the vapor generators of the Atucha I Nuclear Central; Permiso de cambio de limites en los GVs de la CNA-I

    Energy Technology Data Exchange (ETDEWEB)

    Ventura, M. [Autoridad Regulatoria Nuclear, Av. Libertador 8250 (1429), Capital Federal (Argentina)]. e-mail: mventura@sede.arn.gov.ar

    2006-07-01

    In the mark of the modification of the Atucha-I Nuclear Central Installation (CNA-I) as consequence of the Introduction of the System 'Second Drain of Heat' (SSC), the Entity Responsible for the CNA-I (NASA) requested authorization to the Nuclear Regulatory Authority (ARN) to modify the value of the minimum level of water in the secondary side in the Steam generators (GVs) to activate the signal 'shoot of the Cut of the Reactor' (RESA-LLV). As the level in the GVs is one of those parameters that are used to shoot the Emergency Feeding System (RX), component of the SSC System, also was analyzed the change in the activation of the shoot signal of the 'Second Drain of Heat' (2SSC-LLV). The ARN uses for the study of the nuclear safety of nuclear power plants, the series of prediction programs RELAP5/MOD3.X. It participates of the evaluation and maintenance activities of these codes through specific agreements with the U.S. Nuclear Regulatory Commission (US-NRC). It is necessary to account with programs of this type since the ARN it licenses the construction and operation of Nuclear Power Plants (NPPs) and other outstanding facilities and it inquires its operation according to its own standards. With these tools its are auditing the calculations that the Responsible Entities of the operation make to guarantee the operability of the NPPs assisting the mentioned standards. The analysis with computational codes is used as a tool to achieve the best understanding in the behavior of the plant in union with the engineering approach, the manual calculations, the data analysis and the experience in the operation of the machine. (Author)

  17. A generative inference framework for analysing patterns of cultural change in sparse population data with evidence for fashion trends in LBK culture.

    Science.gov (United States)

    Kandler, Anne; Shennan, Stephen

    2015-12-01

    Cultural change can be quantified by temporal changes in frequency of different cultural artefacts and it is a central question to identify what underlying cultural transmission processes could have caused the observed frequency changes. Observed changes, however, often describe the dynamics in samples of the population of artefacts, whereas transmission processes act on the whole population. Here we develop a modelling framework aimed at addressing this inference problem. To do so, we firstly generate population structures from which the observed sample could have been drawn randomly and then determine theoretical samples at a later time t2 produced under the assumption that changes in frequencies are caused by a specific transmission process. Thereby we also account for the potential effect of time-averaging processes in the generation of the observed sample. Subsequent statistical comparisons (e.g. using Bayesian inference) of the theoretical and observed samples at t2 can establish which processes could have produced the observed frequency data. In this way, we infer underlying transmission processes directly from available data without any equilibrium assumption. We apply this framework to a dataset describing pottery from settlements of some of the first farmers in Europe (the LBK culture) and conclude that the observed frequency dynamic of different types of decorated pottery is consistent with age-dependent selection, a preference for 'young' pottery types which is potentially indicative of fashion trends. PMID:26674195

  18. Patterns of landscape evolution on the central and northern Tibetan Plateau investigated using in-situ produced 10Be concentrations from river sediments

    Science.gov (United States)

    Li, Yingkui; Li, Dewen; Liu, Gengnian; Harbor, Jon; Caffee, Marc; Stroeven, Arjen P.

    2014-07-01

    Quantifying long-term erosion rates across the Tibetan Plateau and its bordering mountains is of critical importance to an understanding of the interaction between climate, tectonic movement, and landscape evolution. We present a new dataset of basin-wide erosion rates from the central and northern Tibetan Plateau derived using in-situ produced 10Be concentrations of river sediments. Basin-wide erosion rates from the central plateau range from 10.1±0.9 to 36.8±3.2 mm/kyr, slightly higher than published local erosion rates measured from bedrock surfaces. These values indicate that long-term downwearing of plateau surfaces proceeds at low rates and that the landscape is demonstrably stable in the central plateau. In contrast, basin-wide erosion rates from the Kunlun Shan on the northern Tibetan Plateau range from 19.9±1.7 to 163.2±15.9 mm/kyr. Although the erosion rates of many of these basins are much higher than the rates from the central plateau, they are lower than published basin-wide erosion rates from other mountains fringing the Tibetan Plateau, probably because the basins in the Kunlun Shan include both areas of low-relief plateau surface and high-relief mountain catchments and may also result from retarded fluvial sediment transport in an arid climate. Significantly higher basin-wide erosion rates derived from the Tibetan Plateau margin, compared to the central plateau, reflect a relatively stable plateau surface that is being dissected at its margins by active fluvial erosion.

  19. Texture analysis of collagen second-harmonic generation images based on local difference local binary pattern and wavelets differentiates human skin abnormal scars from normal scars

    Science.gov (United States)

    Liu, Yao; Zhu, Xiaoqin; Huang, Zufang; Cai, Jianyong; Chen, Rong; Xiong, Shuyuan; Chen, Guannan; Zeng, Haishan

    2015-01-01

    Quantitative methods for noninvasive diagnosis of scars are a challenging issue in medicine. This work aims to implement a texture analysis method for quantitatively discriminating abnormal scars from normal scars based on second-harmonic generation (SHG) images. A local difference local binary pattern (LD-LBP) operator combined with a wavelet transform was explored to extract diagnosis features from scar SHG images that were related to the alteration in collagen morphology. Based on the quantitative parameters including the homogeneity, directional and coarse features in SHG images, the scar collagen SHG images were classified into normal or abnormal scars by a support vector machine classifier in a leave-one-out cross-validation procedure. Our experiments and data analyses demonstrated apparent differences between normal and abnormal scars in terms of their morphological structure of collagen. By comparing with gray level co-occurrence matrix, wavelet transform, and combined basic local binary pattern and wavelet transform with respect to the accuracy and receiver operating characteristic analysis, the method proposed herein was demonstrated to achieve higher accuracy and more reliable classification of SHG images. This result indicated that the extracted texture features with the proposed method were effective in the classification of scars. It could provide assistance for physicians in the diagnostic process.

  20. Multimodal function of the sweet taste receptor expressed in pancreatic β-cells: generation of diverse patterns of intracellular signals by sweet agonists.

    Science.gov (United States)

    Nakagawa, Yuko; Nagasawa, Masahiro; Mogami, Hideo; Lohse, Martin; Ninomiya, Yuzo; Kojima, Itaru

    2013-01-01

    The sweet taste receptor is expressed in the taste bud and is activated by numerous sweet molecules with diverse chemical structures. It is, however, not known whether these sweet agonists induce a similar cellular response in target cells. Using MIN6 cells, a pancreatic β-cell line expressing endogenous sweet taste receptor, we addressed this question by monitoring changes in cytoplasmic Ca2+ ([Ca2+]i) and cAMP ([cAMP]i) induced by four sweet taste receptor agonists. Glycyrrhizin evoked sustained elevation of [Ca2+]i but [cAMP]i was not affected. Conversely, an artificial sweetener saccharin induced sustained elevation of [cAMP]i but did not increase [Ca2+]i. In contrast, sucralose and acesulfame K induced rapid and sustained increases in both [Ca2+]i and [cAMP]i. Although the latter two sweeteners increased [Ca2+]i and [cAMP]i, their actions were not identical: [Ca2+]i response to sucralose but not acesulfame K was inhibited by gurmarin, an antagonist of the sweet taste receptor which blocks the gustducin-dependent pathway. In addition, [Ca2+]i response to acesulfame K but not to sucralose was resistant to a Gq inhibitor. These results indicate that four types of sweeteners activate the sweet taste receptor differently and generate distinct patterns of intracellular signals. The sweet taste receptor has amazing multimodal functions producing multiple patterns of intracellular signals. PMID:23933592

  1. Theoretical and computational analysis of second- and third-harmonic generation in periodically patterned graphene and transition-metal dichalcogenide monolayers

    Science.gov (United States)

    Weismann, Martin; Panoiu, Nicolae C.

    2016-07-01

    Remarkable optical and electrical properties of two-dimensional (2D) materials, such as graphene and transition-metal dichalcogenide (TMDC) monolayers, offer vast technological potential for novel and improved optoelectronic nanodevices, many of which rely on nonlinear optical effects in these 2D materials. This paper introduces a highly effective numerical method for efficient and accurate description of linear and nonlinear optical effects in nanostructured 2D materials embedded in periodic photonic structures containing regular three-dimensional (3D) optical materials, such as diffraction gratings and periodic metamaterials. The proposed method builds upon the rigorous coupled-wave analysis and incorporates the nonlinear optical response of 2D materials by means of modified electromagnetic boundary conditions. This allows one to reduce the mathematical framework of the numerical method to an inhomogeneous scattering matrix formalism, which makes it more accurate and efficient than previously used approaches. An overview of linear and nonlinear optical properties of graphene and TMDC monolayers is given and the various features of the corresponding optical spectra are explored numerically and discussed. To illustrate the versatility of our numerical method, we use it to investigate the linear and nonlinear multiresonant optical response of 2D-3D heteromaterials for enhanced and tunable second- and third-harmonic generation. In particular, by employing a structured 2D material optically coupled to a patterned slab waveguide, we study the interplay between geometric resonances associated to guiding modes of periodically patterned slab waveguides and plasmon or exciton resonances of 2D materials.

  2. Mortality pattern of the surrounding population of the Central Nuclear Almirante Alvaro Alberto / 1986 to 2007; Padrao da mortalidade da populacao circunvizinha a Central Nuclear Almirante Alvaro Alberto / 1986 a 2007

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Teresa Cristina Sampaio de Barros; Silva, Ilson Peixoto Medeiros da; Jannuzzi, Denise Maria Souza; Higino, Thiago Nunes; Santos, Tatiana Rodrigues dos [Fundacao Eletronuclear de Assistencia Medica (CIRA/FEAM), Angra dos Reis, RJ (Brazil). Centro de Informacoes sobre Radioepidemiologia; Xavier, Diego Ricardo [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). lnst. de Comunicacao e Informacao Cientifica e Tecnologica; Silva, Roseli Monteiro da [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2011-05-15

    This paper aims to update two earlier epidemiological studies on the mortality profile of the resident population in the influence area of the Central Nuclear Almirante Alvaro Alberto. The main objective is analyze and compare the profile of mortality among the population classified in areas with the distance from source of exposure in three strata. Municipalities contained within a radius of 30 km of the nuclear power, neighboring municipalities, contained within a radius of 30 to 50 km, municipalities contained within 50 to 100 km, beyond Cabo Frio, which presents similar characteristics to the municipality of Angra dos Reis

  3. Compound odontoma associated with impacted maxillary central incisor dictates a need to be vigilant to canine eruption pattern: A 2-year follow-up.

    Science.gov (United States)

    Singla, Shilpy; Gupta, Sachin

    2016-01-01

    Canine deviation from its path of eruption is usually followed by either delayed or impaction of canine. One of the important and not so noticed reasons for canine displacement is formerly impacted central incisor. The difference in age of eruption of these two teeth is 4 years; however, the absence of maxillary incisor should be perceived with utmost conviction about impending canine displacement leading to its impaction as well. This case presents similar picture where composite, compound odontoma with respect to maxillary central incisor led to its impaction resulted in deviated path of eruption for erupting canine. This canine displacement to worsen prognosis ended up getting impacted if not dealt with cautiously in the later stages of occlusal development.

  4. 基于Agent的小世界网络中集中式与分散式创新扩散仿真分析%Research on Simulation of Central and Dispersion Patterns Innovation Diffusion in Small World Network

    Institute of Scientific and Technical Information of China (English)

    严云峰; 李英

    2011-01-01

    An innovation diffusion model with the function of memory is used in the small world network to specify the difference of two diffusion patterns,which are the central pattern and the dispersion pattern.And the result of simulation shows that dispersion pattern is extremely better than the central one, which is reflected in effectiveness, less time, wider coverage and better works in innovation resist network.Further we find that the increase of "Innovation Perceive" can improve the diffusion effectively,cut off time for a node to diffuse in the early period and also which will avoid "Lock in".%在小世界网络中,采用节点具有记忆功能的创新扩散模型进行仿真实验,考察了两种不同的创新扩散方式--集中式扩散和分散式扩散在小世界网络中创新扩散效果的优劣.实验结果表明,在小世界网络中采用分散式扩散要比采用集中式扩散的效果好,具体体现在扩散的时间短、范围广,而且在创新抵触型网络中能更有效地进行扩散.同时更进一步发现,通过增加节点的"创新感知"能有效地改进节点在网络中的扩散效果,大大减少节点在扩散前期所花费的时间,使节点避免出现"Lock-in"现象.

  5. Patterns of mast fruiting of common beech, sessile and common oak, Norway spruce and Scots pine in Central and Northern Europe

    DEFF Research Database (Denmark)

    Nussbaumer, Anita; Waldner, Peter; Etzold, Sophia;

    2016-01-01

    Occurrence of mast years, i.e. the synchronous production of vast amounts of fruits or seeds, has an important impact on forest ecosystems, their functioning and their services. We investigated the mast patterns of the forest tree species common beech, common and sessile oak, Norway spruce and Sc...... hypotheses, and beech and spruce supported the economy of scale, predator satiation and resource allocation hypotheses....

  6. Application of cluster analysis to surface ozone, NO₂ and SO₂ daily patterns in an industrial area in Central-Southern Spain measured with a DOAS system.

    Science.gov (United States)

    Adame, J A; Notario, A; Villanueva, F; Albaladejo, J

    2012-07-01

    The daily variations of surface ozone, NO₂ and SO₂ have been investigated in a heavily industrialised area in the centre of the Iberian Peninsula (Puertollano) using hourly values recorded during two years (2008-2009) with an active LP-DOAS system. The meteorological conditions and air masses have been studied using the HYSPLIT model. The maximum hourly levels of these air pollutants exceeded 100 ppb for ozone, 150 ppb for SO₂ and 210 ppb for NO₂. However, mean values for ozone, NO₂ and SO₂ were of 49, 10 and 3 ppb respectively. Daily-monthly evolutions (defined as daily evolutions for different months) have been analysed in order to know the general daily behaviour of these species. Air pollution problems have been identified using the thresholds defined in the European Directive 2008. The limits to protect human health (human health protection limitations) have been exceeded during the study period. In order to find a set of representative daily cycles for each pollutant at different air quality regimes, a K-mean cluster technique has been applied. Five and four optimal cluster numbers have been obtained for the daily patterns of ozone and SO₂ respectively. In addition, we studied the daily variation of the temperature, relative and specific humidity and wind speed associated with each air pollutant daily pattern. Ozone daily patterns showed typical daily variations with one exception of a cluster which presents a peak in the early morning. For SO₂, the first two clusters present a low mixing ratio, however cluster 3 and 4 are less frequent but with higher levels. The more frequent air pollutant daily patterns do not exceed the threshold defined in the Directive. Nevertheless, clusters with lower frequency (representing between 5 and 7% of days) exceed the thresholds and could be considered as air pollution events. PMID:22591990

  7. Analyzing the impact of rural housing credits on indices of physical development and housing patterns (Case study: villages in the central part of the city of Kashmar

    Directory of Open Access Journals (Sweden)

    Javad Bazrafshan

    2015-06-01

    Full Text Available Giving credit to the villages for physical development and strengthening housing is one of the strategies and programs implemented in rural areas that to some extent, it has caused the empowerment of villages. Some facility will be provided to villagers as the loans of the improvement of rural housing in Iran which have some restrictions and requirements according to infrastructure, materials, and plan of houses and these restrictions and requirements of these houses will distinct them from the traditional rural housing. The goal of this research is the Analyzing the impact of rural housing credits on indices of physical development and housing patterns. The method of the research is analytic-descriptive and the documentary and field methods are used for collecting data. The results show that the dimension of the impact of housing credit on physical development has the maximum effect on the index of the change of rural architecture pattern and in the dimension of housing credits on housing pattern; it has the maximum impact on the index of the type of housing.

  8. Lateralized loss of biting attack-patterned reflexes following induction of contralateral sensory neglect in the cat: a possible role for the striatum in centrally elicited aggressive behaviour.

    Science.gov (United States)

    Bandler, R; Halliday, R

    1982-06-17

    A syndrome of "contralateral sensory neglect' was induced by hypothalamic knife cuts in 6 of 10 cats in which quiet biting attack behaviour could be elicited by lateral hypothalamic stimulation. The contralateral sensory neglect in the 6 affected cats was accompanied by a loss on the "neglected' side of the body of the patterned reflexes which mediate positioning of the head to bite and the jaw-opening component of biting. As a result, when these cats were stimulated in the lateral hypothalamus, although they continued to approach and even make tactile contact with the rat, they generally failed to bite it. Analysis of the histological and behavioural data suggested that damage to the nigrostriatal and/or striato/pallidonigral fibre systems provided the likely basis for both the induction of the contralateral sensory neglect and the lateralized patterned reflex loss. It was suggested, with respect to these specific patterned reflex components of the attack, that an important contribution may be made by the striatum.

  9. Mapping Spatial Patterns of Posidonia oceanica Meadows by Means of Daedalus ATM Airborne Sensor in the Coastal Area of Civitavecchia (Central Tyrrhenian Sea, Italy

    Directory of Open Access Journals (Sweden)

    Marco Marcelli

    2013-10-01

    Full Text Available The spatial distribution of sea bed covers and seagrass in coastal waters is of key importance in monitoring and managing Mediterranean shallow water environments often subject to both increasing anthropogenic impacts and climate change effects. In this context we present a methodology for effective monitoring and mapping of Posidonia oceanica (PO meadows in turbid waters using remote sensing techniques tested by means of LAI (Leaf Area Index point sea truth measurements. Preliminary results using Daedalus airborne sensor are reported referring to the PO meadows at Civitavecchia site (central Tyrrhenian sea where vessel traffic due to presence of important harbors and huge power plant represent strong impact factors. This coastal area, 100 km far from Rome (Central Italy, is characterized also by significant hydrodynamic variations and other anthropogenic factors that affect the health of seagrass meadows with frequent turbidity and suspended sediments in the water column. During 2011–2012 years point measurements of several parameters related to PO meadows phenology were acquired on various stations distributed along 20 km of coast between the Civitavecchia and S. Marinella sites. The Daedalus airborne sensor multispectral data were preprocessed with the support of satellite (MERIS derived water quality parameters to obtain here improved thematic maps of the local PO distribution. Their thematic accuracy was then evaluated as agreement (R2 with the point sea truth measurements and regressive modeling using an on purpose developd method.

  10. Fractal systems of central places based on intermittency of space-filling

    International Nuclear Information System (INIS)

    Highlights: → The idea of intermittency is introduced into central place model. → The revised central place model suggests incomplete space filling. → New central place fractals are presented for urban analysis. → The average nearest distance is proposed to estimate the fractal dimension. → The concept of distance-based space is replaced by that of dimension-based space. - Abstract: The central place models are fundamentally important in theoretical geography and city planning theory. The texture and structure of central place networks have been demonstrated to be self-similar in both theoretical and empirical studies. However, the underlying rationale of central place fractals in the real world has not yet been revealed so far. This paper is devoted to illustrating the mechanisms by which the fractal patterns can be generated from central place systems. The structural dimension of the traditional central place models is d = 2 indicating no intermittency in the spatial distribution of human settlements. This dimension value is inconsistent with empirical observations. Substituting the complete space filling with the incomplete space filling, we can obtain central place models with fractional dimension D < d = 2 indicative of spatial intermittency. Thus the conventional central place models are converted into fractal central place models. If we further integrate the chance factors into the improved central place fractals, the theory will be able to explain the real patterns of urban places very well. As empirical analyses, the US cities and towns are employed to verify the fractal-based models of central places.

  11. The Research on Fund Centralized Management Informatization based on the Pattern of Financial Company%财务公司模式下资金集中管理信息化研究

    Institute of Scientific and Technical Information of China (English)

    唐忠良

    2015-01-01

    推进资金集中管理信息化是现代企业集团持续健康发展的必由之路。文章基于实务与理论界关于我国企业集团资金集中管理信息化研究的现状,对企业集团财务公司模式下如何实现资金集中管理信息化进行了研究。为了找出一条全面、可行的提升我国企业集团财务公司模式下资金集中管理信息化水平的路径,文章首先从总体框架与技术角度指出了资金集中管理信息化蓝图,并进一步从建设原则、六大功能模块、安全保障方面论述了如何构建资金集中管理信息化平台,最后提出了顺利推进企业集团资金集中管理信息化建设需要注意的因素。研究为我国企业集团通过信息化手段提升资金集中管理水平提供了思路,为我国企业集团从战略与实施层面构建立安全、高效、集成的资金集中管理信息化平台指明了方向。%Propelling fund centralized management informatization is the only way for sustained and healthy development of modern enterprise group. This article based on the practice and theory of enterprise group fund centralized management informatization currently , elaborates how to realize enterprise group fund centralized management informatization under the pattern of financial company. In order to find a comprehensive and viable way to enhance enterprise group fund centralized management informatization level under the pattern of financial company, this paper firstly points out a blueprint of fund centralized management informatization from overall framework and technical view, furthermore analyzes how to build a fund centralized management informatization platform which includes six function modules, security and other aspects, finally points out the factors of smoothly advances fund centralized management informatization. The research provides the ideas of enterprise group how to promote the level of fund centralized management by means

  12. Intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera (Anura, Leptodactylidae) with inclusion of five species from Central Amazonia.

    Science.gov (United States)

    Coelho, Ana Carolina; de Mattos, Thais Lemos; Viana, Patrik; Terencio, Maria Leandra; Schneider, Carlos Henrique; Menin, Marcelo; Gross, Maria Claudia

    2016-02-01

    The genera Leptodactylus and Adenomera comprise 92 species distributed throughout the Neotropical region. These species have a modal diploid chromosome number 2n = 22. However, chromosome rearrangements are evident in the differentiation of five intra-generic groups in the genus Leptodactylus (L. fuscus, L. latrans, L. marmoratus (formally composed by the species of the genus Adenomera), L. melanonotus, L. pentadactylus), yet it is not clear if there is a karyotype pattern for each group. Aiming to understand the intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera, cytogenetic analyses were performed in A. andreae, L. macrosternum, L. pentadactylus, L. petersii, and L. riveroi using conventional staining, C-banding, nucleolus organizer region (NOR) and hybridization in situ fluorescent (FISH). The karyotype of Leptodactylus riveroi was described for the first time. Adenomera andreae had 2n = 26, while the remaining species 2n = 22. The NOR was found on pair No. 8 of A. andreae, L. macrosternum, L. pentadactylus, and L. riveroi, whereas L. petersii had it on pairs Nos. 6 and 10. These locations were confirmed by the FISH with 18S rDNA probe, except for pair No. 10 of L. petersii. The C-banding pattern was evident at the centromeres of chromosomes of all species and some interspecific variations were also observed. 2n = 22 was observed in the species of the L. latrans group, as well as in the intra-generic groups L. fuscus and L. pentadactylus; in the L. melanonotus group there were three diploid chromosome numbers 2n = 20, 22 and 24; and a larger variation in 2n was also evident in the L. marmoratus group.

  13. Fractal Systems of Central Places Based on Intermittency of Space-filling

    CERN Document Server

    Chen, Yanguang

    2011-01-01

    The central place models are fundamentally important in theoretical geography and city planning theory. The texture and structure of central place networks have been demonstrated to be self-similar in both theoretical and empirical studies. However, the underlying rationale of central place fractals in the real world has not yet been revealed so far. This paper is devoted to illustrating the mechanisms by which the fractal patterns can be generated from central place systems. The structural dimension of the traditional central place models is d=2 indicating no intermittency in the spatial distribution of human settlements. This dimension value is inconsistent with empirical observations. Substituting the complete space filling with the incomplete space filling, we can obtain central place models with fractional dimension Dcentral place models are converted into fractal central place models. If we further integrate the chance factors into the i...

  14. Transcriptional Profiling of Newly Generated Dentate Granule Cells Using TU Tagging Reveals Pattern Shifts in Gene Expression during Circuit Integration1,2

    Science.gov (United States)

    Chatzi, Christina; Shen, Rongkun; Goodman, Richard H.

    2016-01-01

    Abstract Despite representing only a small fraction of hippocampal granule cells, adult-generated newborn granule cells have been implicated in learning and memory (Aimone et al., 2011). Newborn granule cells undergo functional maturation and circuit integration over a period of weeks. However, it is difficult to assess the accompanying gene expression profiles in vivo with high spatial and temporal resolution using traditional methods. Here we used a novel method [“thiouracil (TU) tagging”] to map the profiles of nascent mRNAs in mouse immature newborn granule cells compared with mature granule cells. We targeted a nonmammalian uracil salvage enzyme, uracil phosphoribosyltransferase, to newborn neurons and mature granule cells using retroviral and lentiviral constructs, respectively. Subsequent injection of 4-TU tagged nascent RNAs for analysis by RNA sequencing. Several hundred genes were significantly enhanced in the retroviral dataset compared with the lentiviral dataset. We compared a selection of the enriched genes with steady-state levels of mRNAs using quantitative PCR. Ontology analysis revealed distinct patterns of nascent mRNA expression, with newly generated immature neurons showing enhanced expression for genes involved in synaptic function, and neural differentiation and development, as well as genes not previously associated with granule cell maturation. Surprisingly, the nascent mRNAs enriched in mature cells were related to energy homeostasis and metabolism, presumably indicative of the increased energy demands of synaptic transmission and their complex dendritic architecture. The high spatial and temporal resolution of our modified TU-tagging method provides a foundation for comparison with steady-state RNA analyses by traditional transcriptomic approaches in defining the functional roles of newborn neurons. PMID:27011954

  15. Performance and variability patterns in wood properties and growth traits in the parents, F1 and F2 generation hybrid clones of Populus deltoides

    Institute of Scientific and Technical Information of China (English)

    P. K. Pande; R. C. Dhiman

    2011-01-01

    The performance and variability patterns in the wood ele- ment's dimensions, specific gravity and growth parameters namely ramet height and GBH were evaluated in 16 clones of parents, F1 and F2 hy- brids of Populus deltoides Bartr. Ex Marsh. Ramet radial variations were non-significant, while inter-clonal variations due to interaction of clone/replication were significant for all the wood traits except vessel element length. Inter-clonal variations were significant only for fiber length and fiber wall thickness. Fiber length and specific gravity were significantly higher in female, while wall thickness and vessel element length were higher in male clones. Female parents (G48 and S7C8) showed higher flber length and specific gravity than of the male parent (G3), while vessel diameter and wall thickness were higher in male par- ent (G3). There is not much difference in fiber length and vessel ele- ment's dimensions among the parents, F1 and F2 generation hybrid clones. Specific gravity did not showed any trend for parents, F1 and F2 generations. Generally female clones showed higher growth rate. Broad sense heritability for wood traits ranged from 0.143 (fiber length) to 0.505 (fiber wall thickness), while for growth Waits it was 0.374 (GBH) and 0.418 (height). Genetic gain for all the wood and growth traits was positive for most of the wood waits. The highly divergent male clone (78) and female clones (S7C8, G48, W/A 49) in number of combinations could be used for developing new hybrids of desired wood traits to de- velop new clones.

  16. Gene actions for yield and its attributes and their implications in the inheritance pattern over three generations in opium poppy (Papaver somniferum L.).

    Science.gov (United States)

    Mishra, Brij K; Mishra, R; Jena, S N; Shukla, Sudhir

    2016-09-01

    The gene actions for yield and its attributes and their inheritance pattern based on five parameter model have been explored in four single crosses (NBIHT-5 × NBIHT-6, NBIHT-5 × NBMHT-1, NBMHT-1 × NBIHT-6 and NBMHT-2 × NBMHT-1) obtained using thebaine rich pure lines of opium poppy (Papaver somniferum L.) for three consecutive generations. All the traits showed nonallelic mode of interaction, however, dominance effect (h) was more pronounced for all the traits except thebaine and papaverine. The dominance × dominance (l) effects were predominant over additive × additive (i) for all traits in all the four crosses except for papaverine. The seed and opium yield, and its contributing traits inherited quantitatively. The fixable gene effects (d) and (i) were lower in magnitude than nonfixable (h) and (l) gene effects. The estimates of heterosis were also higher in comparison to the respective parents which suggested preponderance of dominance gene action for controlling most of the traits. The phenotypic coefficient of variation was marginally higher than those of genotypic coefficient of variation for all the traits. The traits thebaine, narcotine, morphine and opium yield had high heritability coupled with high genetic advance. The leaf number, branches per plant and stem diameter showed positive correlation with opium and seed yields. The selection of plants having large number of leaves, branches and capsules with bigger size would be advantageous to enhance the yield potential. PMID:27659342

  17. Gene actions for yield and its attributes and their implications in the inheritance pattern over three generations in opium poppy ( Papaver somniferum L.)

    Indian Academy of Sciences (India)

    BRIJ K. MISHRA; R. MISHRA; S.N. JENA; SUDHIR SHUKLA

    2016-09-01

    The gene actions for yield and its attributes and their inheritance pattern based on five parameter model have been explored in four single crosses (NBIHT-5 ×NBIHT-6, NBIHT-5×NBMHT-1, NBMHT-1× NBIHT-6 and NBMHT-2× NBMHT-1) obtained using thebaine rich pure lines of opium poppy (Papaver somniferum L.) for three consecutive generations. All the traits showed nonallelic mode of interaction, however, dominance effect (h) was more pronounced for all the traits exceptthebaine and papaverine. The dominance × dominance (l) effects were predominant over additive × additive (i) for all traits in all the four crosses except for papaverine. The seed and opium yield, and its contributing traits inherited quantitatively. The fixable gene effects (d) and (i) were lower in magnitude than nonfixable (h) and (l) gene effects. The estimates of heterosis werealso higher in comparison to the respective parents which suggested preponderance of dominance gene action for controlling most of the traits. The phenotypic coefficient of variation was marginally higher than those of genotypic coefficient of variation for all the traits. The traits thebaine, narcotine, morphine and opium yield had high heritability coupled with high genetic advance. The leaf number, branches per plant and stem diameter showed positive correlation with opium and seed yields. The selection of plants having large number of leaves, branches and capsules with bigger size would be advantageous to enhancethe yield potential.