Science.gov

Sample records for pattern generator development

  1. Development of a morphing structure with the incorporation of central pattern generators

    NASA Astrophysics Data System (ADS)

    Bliss, Thomas K.; Bart-Smith, Hilary; Iwasaki, Tetsuya

    2006-03-01

    The Manta Ray, Manta birostris, is an amazing creature, propelling itself through the water with the elegant and complex flapping of its wings. Achieving outstanding efficiencies, engineers are looking for ways to mimic its flight through the water and harness its propulsive techniques. This study combines two biologically inspired aspects to achieve this goal: morphing structures actuated with a biomimetic neural network control system. It is believed that this combination will prove capable of producing the oscillatory motions necessary for locomotion. In this paper, a four-truss structure with three actuators is chosen and its performance capabilities are analyzed. A synthetic central pattern generator, which provides the fundamental control mechanisms for rhythmic motion in animals, is designed to realize an oscillatory control of the three actuators. The control system is simulated using Matlab, then combined with LabVIEW to control the four-truss structure. The system's performance is analyzed, with specific attention to both transient and steady-state behavior.

  2. Development of a diurnal rainfall pattern generator and assessment of climate change impact on flood risk in Japan

    NASA Astrophysics Data System (ADS)

    Minakawa, H.; Masumoto, T.

    2011-12-01

    An increase in flood risk, especially in low-lying areas, is predicted as a consequence of global climate change. Immediate measures are needed to minimize the damage caused by more-frequent flooding. The capacities of drainage systems in paddy areas are planned on the basis of design rainfall. For example, design rainfall may be represented by a 3-day rainfall event with a 10-year return period. However, design rainfall parameters used in Japan have not been reviewed for a few decades, and changes in rainfall patterns associated with recent climate change are not reflected in current drainage planning. The aim of this study was to develop a diurnal rainfall pattern generator and to use it to evaluate the effects of changing patterns of heavy rainfall due to climate change on flood risk in low-lying areas. Our study area was in the Kaga three-lagoon basin in Ishikawa Prefecture, Japan. There are two lagoons in the study area, and the low-lying paddy areas extend over about 4,000 ha in the lower reaches of the basin. First, we developed a drainage analysis model that incorporates kinematic and diffusive runoff models for upland and inundated areas, respectively. The model was adjusted in accordance with observed discharges and water levels for heavy rainfall events. Next, the rainfall data predicted by MIROC (a Global Climate Model developed by the Center for Climate Systems Research) were analyzed to determine the future trends of changes of heavy rainfall. Our analysis showed that probabilistic 3-day rainfall would increase in the future. In particular, 3-day rainfall events with a 10-year return period were calculated to increase from about 220 mm/3d at present to about 270 mm/3d in the future. These amounts of rainfall were used to represent the future trend of increases of heavy rainfall. Simultaneously, we developed a diurnal rainfall pattern generator based on a Monte Carlo simulation method. For this generator, the beta distribution was used to disaggregate

  3. Resolution Improvement and Pattern Generator Development for theMaskless Micro-Ion-Beam Reduction Lithography System

    SciTech Connect

    Jiang, Ximan

    2006-05-18

    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.

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

    PubMed Central

    2014-01-01

    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 spinal cord-injured (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 SCI patients. PMID:24910602

  5. The Growing Canvas of Biological Development: Multiscale Pattern Generation on an Expanding Lattice of Gene Regulatory Nets

    NASA Astrophysics Data System (ADS)

    Doursat, René

    The spontaneous generation of an entire organism from a single cell is the epitome of a self-organizing, decentralized complex system. How do nonspatial gene interactions extend in 3-D space? In this work, I present a simple model that simulates some biological developmental principles using an expanding lattice of cells. Each cell contains a gene regulatory network (GRN), modeled as a feedforward hierarchy of switches that can settle in various on/off expression states. Local morphogen gradients provide positional information in input, which is integrated by each GRN to produce differential expression of identity genes in output. Similarly to striping in the Drosophila embryo, the lattice becomes segmented into spatial regions of homogeneous genetic expression that resemble stained-glass motifs. Meanwhile, it also expands by cell proliferation, creating new local gradients of positional information within former single-identity regions. Analogous to a "growing canvas" painting itself, the alternation of growth and patterning results in the creation of a form. This preliminary study attempts to reproduce pattern formation through a multiscale, recursive and modular process. It explores the elusive relationship between nonspatial GRN weights (genotype) and spatial patterns (phenotype). Abstracting from biology in the same spirit as neural networks or swarm optimization, I hope to be contributing to a novel engineering paradigm of system construction that could complement or replace omniscient architects with decentralized collectivities of agents.

  6. Patterns of gender development.

    PubMed

    Martin, Carol Lynn; Ruble, Diane N

    2010-01-01

    A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains-sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development.

  7. Patterns of Gender Development

    PubMed Central

    Martin, Carol Lynn; Ruble, Diane N.

    2013-01-01

    A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains—sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development. PMID:19575615

  8. Automatically generating extraction patterns from untagged text

    SciTech Connect

    Riloff, E.

    1996-12-31

    Many corpus-based natural language processing systems rely on text corpora that have been manually annotated with syntactic or semantic tags. In particular, all previous dictionary construction systems for information extraction have used an annotated training corpus or some form of annotated input. We have developed a system called AutoSlog-TS that creates dictionaries of extraction patterns using only untagged text. AutoSlog-TS is based on the AutoSlog system, which generated extraction patterns using annotated text and a set of heuristic rules. By adapting AutoSlog and combining it with statistical techniques, we eliminated its dependency on tagged text. In experiments with the MUC-4 terrorism domain, AutoSlog-TS created a dictionary of extraction patterns that performed comparably to a dictionary created by AutoSlog, using only preclassified texts as input.

  9. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, Michiyuki

    1981-01-01

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Also, apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  10. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, N.M.I.

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base is described. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  11. Regulation of the respiratory central pattern generator by chloride-dependent inhibition during development in the bullfrog (Rana catesbeiana).

    PubMed

    Broch, Lise; Morales, Rey D; Sandoval, Anthony V; Hedrick, Michael S

    2002-04-01

    Isolated brainstem preparations from larval (tadpole) and adult Rana catesbeiana were used to examine inhibitory mechanisms for developmental regulation of the respiratory central pattern generator (CPG). Preparations were superfused at 20-22 degrees C with Cl(-)-free artificial cerebrospinal fluid (aCSF) or with aCSF containing agonists/antagonists of gamma-aminobutyric acid (GABA) or glycine receptors. Respiratory motor output from the CPG, measured as neural activity from cranial nerve roots, was associated with fictive gill ventilation and lung ventilation in tadpoles and with fictive lung ventilation in adults. In tadpoles, fictive lung burst frequency was 0.8+/-0.2 min(-1) and did not change significantly with Cl(-)-free aCSF superfusion; however, lung burst amplitude increased by nearly 400 % (P<0.01). Fictive gill ventilation averaged 41.6+/-3.3 min(-1) and was reversibly abolished by Cl(-)-free aCSF. Superfusion with Cl(-)-free aCSF abolished lung bursts in two of seven adult preparations, and overall lung burst frequency decreased from 3.1+/-0.7 to 0.4+/-0.03 min(-1) (P<0.01), but burst amplitude was unchanged. Low concentrations of GABA (0.5 mmol l(-1)) produced a significant increase in lung burst frequency followed by almost complete inhibition at 5.0 mmol l(-1), accompanied by the abolition of gill ventilation at 2.5-5.0 mmol l(-1). By contrast, fictive lung ventilation in adults was inhibited in a dose-dependent manner by glycine and GABA, and inhibition occurred at approximately 10-fold lower concentrations compared with tadpoles. The glycine receptor antagonist strychnine (2.5-25.0 micromol l(-1)) and the GABA(A) receptor antagonist bicuculline (1-10 micromol l(-1)) inhibited fictive gill ventilation and increased fictive lung ventilation in tadpoles. However, bicuculline and strychnine inhibited fictive lung ventilation in adults. These results suggest that lung ventilation in the tadpole brainstem may be driven by a pacemaker-like mechanism since

  12. Patterning techniques for next generation IC's

    NASA Astrophysics Data System (ADS)

    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.

  13. Patterns to Develop Algebraic Reasoning

    ERIC Educational Resources Information Center

    Stump, Sheryl L.

    2011-01-01

    What is the role of patterns in developing algebraic reasoning? This important question deserves thoughtful attention. In response, this article examines some differing views of algebraic reasoning, discusses a controversy regarding patterns, and describes how three types of patterns--in contextual problems, in growing geometric figures, and in…

  14. Laboratory development TPV generator

    NASA Astrophysics Data System (ADS)

    Holmquist, Glenn A.; Wong, Eva M.; Waldman, Cye H.

    1996-02-01

    A laboratory model of a TPV generator in the kilowatt range was developed and tested. It was based on methane/oxygen combustion and a spectrally matched selective emitter/collector pair (ytterbia emitter-silicon PV cell). The system demonstrated a power output of 2.4 kilowatts at an overall efficiency of 4.5% without recuperation of heat from the exhaust gases. Key aspects of the effort include: 1) process development and fabrication of mechanically strong selective emitter ceramic textile materials; 2) design of a stirred reactor emitter/burner capable of handling up to 175,000 Btu/hr fuel flows; 3) support to the developer of the production silicon concentrator cells capable of withstanding TPV environments; 4) assessing the apparent temperature exponent of selective emitters; and 5) determining that the remaining generator efficiency improvements are readily defined combustion engineering problems that do not necessitate breakthrough technology. The fiber matrix selective emitter ceramic textile (felt) was fabricated by a relic process with the final heat-treatment controlling the grain growth in the porous ceramic fiber matrix. This textile formed a cylindrical cavity for a stirred reactor. The ideal stirred reactor is characterized by constant temperature combustion resulting in a uniform reactor temperature. This results in a uniform radiant emission from the emitter. As a result of significant developments in the porous emitter matrix technology, a TPV generator burner/emitter was developed that produced kilowatts of radiant energy.

  15. Two-stage Turing model for generating pigment patterns on the leopard and the jaguar

    NASA Astrophysics Data System (ADS)

    Liu, R. T.; Liaw, S. S.; Maini, P. K.

    2006-07-01

    Based on the results of phylogenetic analysis, which showed that flecks are the primitive pattern of the felid family and all other patterns including rosettes and blotches develop from it, we construct a Turing reaction-diffusion model which generates spot patterns initially. Starting from this spotted pattern, we successfully generate patterns of adult leopards and jaguars by tuning parameters of the model in the subsequent phase of patterning.

  16. Silicon central pattern generators for cardiac diseases.

    PubMed

    Nogaret, Alain; O'Callaghan, Erin L; Lataro, Renata M; Salgado, Helio C; Meliza, C Daniel; Duncan, Edward; Abarbanel, Henry D I; Paton, Julian F R

    2015-02-15

    Cardiac rhythm management devices provide therapies for both arrhythmias and resynchronisation but not heart failure, which affects millions of patients worldwide. This paper reviews recent advances in biophysics and mathematical engineering that provide a novel technological platform for addressing heart disease and enabling beat-to-beat adaptation of cardiac pacing in response to physiological feedback. The technology consists of silicon hardware central pattern generators (hCPGs) that may be trained to emulate accurately the dynamical response of biological central pattern generators (bCPGs). We discuss the limitations of present CPGs and appraise the advantages of analog over digital circuits for application in bioelectronic medicine. To test the system, we have focused on the cardio-respiratory oscillators in the medulla oblongata that modulate heart rate in phase with respiration to induce respiratory sinus arrhythmia (RSA). We describe here a novel, scalable hCPG comprising physiologically realistic (Hodgkin-Huxley type) neurones and synapses. Our hCPG comprises two neurones that antagonise each other to provide rhythmic motor drive to the vagus nerve to slow the heart. We show how recent advances in modelling allow the motor output to adapt to physiological feedback such as respiration. In rats, we report on the restoration of RSA using an hCPG that receives diaphragmatic electromyography input and use it to stimulate the vagus nerve at specific time points of the respiratory cycle to slow the heart rate. We have validated the adaptation of stimulation to alterations in respiratory rate. We demonstrate that the hCPG is tuneable in terms of the depth and timing of the RSA relative to respiratory phase. These pioneering studies will now permit an analysis of the physiological role of RSA as well as its any potential therapeutic use in cardiac disease. PMID:25433077

  17. Silicon central pattern generators for cardiac diseases

    PubMed Central

    Nogaret, Alain; O'Callaghan, Erin L; Lataro, Renata M; Salgado, Helio C; Meliza, C Daniel; Duncan, Edward; Abarbanel, Henry D I; Paton, Julian F R

    2015-01-01

    Cardiac rhythm management devices provide therapies for both arrhythmias and resynchronisation but not heart failure, which affects millions of patients worldwide. This paper reviews recent advances in biophysics and mathematical engineering that provide a novel technological platform for addressing heart disease and enabling beat-to-beat adaptation of cardiac pacing in response to physiological feedback. The technology consists of silicon hardware central pattern generators (hCPGs) that may be trained to emulate accurately the dynamical response of biological central pattern generators (bCPGs). We discuss the limitations of present CPGs and appraise the advantages of analog over digital circuits for application in bioelectronic medicine. To test the system, we have focused on the cardio-respiratory oscillators in the medulla oblongata that modulate heart rate in phase with respiration to induce respiratory sinus arrhythmia (RSA). We describe here a novel, scalable hCPG comprising physiologically realistic (Hodgkin–Huxley type) neurones and synapses. Our hCPG comprises two neurones that antagonise each other to provide rhythmic motor drive to the vagus nerve to slow the heart. We show how recent advances in modelling allow the motor output to adapt to physiological feedback such as respiration. In rats, we report on the restoration of RSA using an hCPG that receives diaphragmatic electromyography input and use it to stimulate the vagus nerve at specific time points of the respiratory cycle to slow the heart rate. We have validated the adaptation of stimulation to alterations in respiratory rate. We demonstrate that the hCPG is tuneable in terms of the depth and timing of the RSA relative to respiratory phase. These pioneering studies will now permit an analysis of the physiological role of RSA as well as its any potential therapeutic use in cardiac disease. PMID:25433077

  18. Identifying network topologies that can generate turing pattern.

    PubMed

    Zheng, M Mocarlo; Shao, Bin; Ouyang, Qi

    2016-11-01

    Turing pattern provides a paradigm of non-equilibrium self-organization in reaction-diffusion systems. On the basis of many mathematical studies, it has been proposed that various biological development processes use Turing instability to achieve periodic patterns. In this paper, we introduce a framework to systematic identify network topologies that are capable for Turing pattern formation. All possible 2, 3-node genetic regulatory networks are enumerated and linear stability analysis is applied to access their ability to generate Turing instability. We find that all 3-node networks that can achieve Turing pattern can be mapped to either pure or cross activator-inhibitor mechanisms, and the pure activator-inhibitor system is more robust for Turing pattern formation than the other one. Additional linkages can further increase the performance of the circuit by either introducing another core topology or complementing existing regulations. Moreover, we find that addition of a fixed node enables the formation of Turing pattern even when the diffusion coefficients of two morphogens are fairly close to each other. Our results provide the design principle of robust circuits for Turing pattern generation and can be further applied for systematically exploring other bifurcation phenomena. PMID:27519949

  19. Modeling Scalable Pattern Generation in DNA Reaction Networks

    PubMed Central

    Allen, Peter B.; Chen, Xi; Simpson, Zack B.; Ellington, Andrew D.

    2013-01-01

    We have developed a theoretical framework for developing patterns in multiple dimensions using controllable diffusion and designed reactions implemented in DNA. This includes so-called strand displacement reactions in which one single-stranded DNA hybridizes to a hemi-duplex DNA and displaces another single-stranded DNA, reversibly or irreversibly. These reactions can be designed to proceed with designed rate and molecular specificity. By also controlling diffusion by partial complementarity to a stationary, cross-linked DNA, we can generate predictable patterns. We demonstrate this with several simulations showing deterministic, predictable shapes in space. PMID:25506295

  20. Central pattern generator for swimming in Melibe.

    PubMed

    Thompson, Stuart; Watson, Winsor H

    2005-04-01

    The nudibranch mollusc Melibe leonina swims by bending from side to side. We have identified a network of neurons that appears to constitute the central pattern generator (CPG) for this locomotor behavior, one of only a few such networks to be described in cellular detail. The network consists of two pairs of interneurons, termed 'swim interneuron 1' (sint1) and 'swim interneuron 2' (sint2), arranged around a plane of bilateral symmetry. Interneurons on one side of the brain, which includes the paired cerebral, pleural and pedal ganglia, coordinate bending movements toward the same side and communicate via non-rectifying electrical synapses. Interneurons on opposite sides of the brain coordinate antagonistic movements and communicate over mutually inhibitory synaptic pathways. Several criteria were used to identify members of the swim CPG, the most important being the ability to shift the phase of swimming behavior in a quantitative fashion by briefly altering the firing pattern of an individual neuron. Strong depolarization of any of the interneurons produces an ipsilateral swimming movement during which the several components of the motor act occur in sequence. Strong hyperpolarization causes swimming to stop and leaves the animal contracted to the opposite side for the duration of the hyperpolarization. The four swim interneurons make appropriate synaptic connections with motoneurons, exciting synergists and inhibiting antagonists. Finally, these are the only neurons that were found to have this set of properties in spite of concerted efforts to sample widely in the Melibe CNS. This led us to conclude that these four cells constitute the CPG for swimming. While sint1 and sint2 work together during swimming, they play different roles in the generation of other behaviors. Sint1 is normally silent when the animal is crawling on a surface but it depolarizes and begins to fire in strong bursts once the foot is dislodged and the animal begins to swim. Sint2 also fires

  1. Generating Coherent Patterns of Activity from Chaotic Neural Networks

    PubMed Central

    Sussillo, David; Abbott, L. F.

    2009-01-01

    Neural circuits display complex activity patterns both spontaneously and when responding to a stimulus or generating a motor output. How are these two forms of activity related? We develop a procedure called FORCE learning for modifying synaptic strengths either external to or within a model neural network to change chaotic spontaneous activity into a wide variety of desired activity patterns. FORCE learning works even though the networks we train are spontaneously chaotic and we leave feedback loops intact and unclamped during learning. Using this approach, we construct networks that produce a wide variety of complex output patterns, input-output transformations that require memory, multiple outputs that can be switched by control inputs, and motor patterns matching human motion capture data. Our results reproduce data on pre-movement activity in motor and premotor cortex, and suggest that synaptic plasticity may be a more rapid and powerful modulator of network activity than generally appreciated. PMID:19709635

  2. Generation 1.5 Written Error Patterns: A Comparative Study

    ERIC Educational Resources Information Center

    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…

  3. Generating spatiotemporal joint torque patterns from dynamical synchronization of distributed pattern generators.

    PubMed

    Pitti, Alexandre; Lungarella, Max; Kuniyoshi, Yasuo

    2009-01-01

    Pattern generators found in the spinal cord are no more seen as simple rhythmic oscillators for motion control. Indeed, they achieve flexible and dynamical coordination in interaction with the body and the environment dynamics giving to rise motor synergies. Discovering the mechanisms underlying the control of motor synergies constitutes an important research question not only for neuroscience but also for robotics: the motors coordination of high dimensional robotic systems is still a drawback and new control methods based on biological solutions may reduce their overall complexity. We propose to model the flexible combination of motor synergies in embodied systems via partial phase synchronization of distributed chaotic systems; for specific coupling strength, chaotic systems are able to phase synchronize their dynamics to the resonant frequencies of one external force. We take advantage of this property to explore and exploit the intrinsic dynamics of one specified embodied system. In two experiments with bipedal walkers, we show how motor synergies emerge when the controllers phase synchronize to the body's dynamics, entraining it to its intrinsic behavioral patterns. This stage is characterized by directed information flow from the sensors to the motors exhibiting the optimal situation when the body dynamics drive the controllers (mutual entrainment). Based on our results, we discuss the relevance of our findings for modeling the modular control of distributed pattern generators exhibited in the spinal cord, and for exploring the motor synergies in robots. PMID:20011216

  4. Standard Transistor Array (STAR). Volume 2: Test pattern generation

    NASA Technical Reports Server (NTRS)

    Carroll, B. D.

    1979-01-01

    Testing of large scale integrated logic circuits is considered from the point-of-view of automatic test pattern generation. A logic simulator based approach for automatic test pattern generation is taken and is described. The logic model and the timing model used in the simulator are also described. Two methods are presented for generating test patterns from the output of the simulator. Recommendations for future study are also presented.

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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.

  7. Pattern generation requirements for mask making beyond 130 nm

    NASA Astrophysics Data System (ADS)

    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

  8. Nonlinear ring resonator: spatial pattern generation

    NASA Astrophysics Data System (ADS)

    Ivanov, Vladimir Y.; Lachinova, Svetlana L.; Irochnikov, Nikita G.

    2000-03-01

    We consider theoretically spatial pattern formation processes in a unidirectional ring cavity with thin layer of Kerr-type nonlinear medium. Our method is based on studying of two coupled equations. The first is a partial differential equation for temporal dynamics of phase modulation of light wave in the medium. It describes nonlinear interaction in the Kerr-type lice. The second is a free propagation equation for the intracavity field complex amplitude. It involves diffraction effects of light wave in the cavity.

  9. Complex expression patterns of lymphocyte-specific genes during the development of cartilaginous fish implicate unique lymphoid tissues in generating an immune repertoire

    NASA Technical Reports Server (NTRS)

    Miracle, A. L.; Anderson, M. K.; Litman, R. T.; Walsh, C. J.; Luer, C. A.; Rothenberg, E. V.; Litman, G. W.

    2001-01-01

    Cartilaginous fish express canonical B and T cell recognition genes, but their lymphoid organs and lymphocyte development have been poorly defined. Here, the expression of Ig, TCR, recombination-activating gene (Rag)-1 and terminal deoxynucleosidase (TdT) genes has been used to identify roles of various lymphoid tissues throughout development in the cartilaginous fish, Raja eglanteria (clearnose skate). In embryogenesis, Ig and TCR genes are sharply up-regulated at 8 weeks of development. At this stage TCR and TdT expression is limited to the thymus; later, TCR gene expression appears in peripheral sites in hatchlings and adults, suggesting that the thymus is a source of T cells as in mammals. B cell gene expression indicates more complex roles for the spleen and two special organs of cartilaginous fish-the Leydig and epigonal (gonad-associated) organs. In the adult, the Leydig organ is the site of the highest IgM and IgX expression. However, the spleen is the first site of IgM expression, while IgX is expressed first in gonad, liver, Leydig and even thymus. Distinctive spatiotemporal patterns of Ig light chain gene expression also are seen. A subset of Ig genes is pre-rearranged in the germline of the cartilaginous fish, making expression possible without rearrangement. To assess whether this allows differential developmental regulation, IgM and IgX heavy chain cDNA sequences from specific tissues and developmental stages have been compared with known germline-joined genomic sequences. Both non-productively rearranged genes and germline-joined genes are transcribed in the embryo and hatchling, but not in the adult.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Mask patterning for the 22nm node using a proton multi-beam projection pattern generator

    NASA Astrophysics Data System (ADS)

    Butschke, Joerg; Irmscher, Mathias; Sailer, Holger; Nedelmann, Lorenz; Pritschow, Marcus; Loeschner, Hans; Platzgummer, Elmar

    2008-10-01

    Decreasing throughput of high-end pattern generators and insufficient line edge roughness (LER) of chemically amplified resists (CAR) might become limitations for future mask making. An alternative could be the introduction of less sensitive resists, linked to a turning away from today's electron beam pattern generators. Moderate exposure doses of around 25μC/cm2 could be achieved for non-CAR materials like HSQ by the use of 10keV protons. Targeting optimized absorber performance, Shin-Etsu has developed an Opaque-molybdenum-over-glass (OMOG) material, designed for 32mn mask technology and beyond. This hard mask concept allows using thin resist layers, as required by an ion beam exposure. Goal of this work was to assess a HSQ based non-CAR process using a multiple ion beam pattern generator including subsequent transfer into the absorber by dry etch processes. Proton exposures have been done on the IMS Nanofabrication proof of concept tool which is designed for 40,000 programmable ion beams. For comparison, an electron based reference process has been set up in parallel to the proton multi-beam approach. Hard mask opening and subsequent absorber etching have been accomplished in a state of the art mask etcher. Assessment of the process flow has been done in terms of feature profile, LER and resolution capability.

  12. Automated branching pattern report generation for laparoscopic surgery assistance

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Matsuzaki, Tetsuro; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

    2015-05-01

    This paper presents a method for generating branching pattern reports of abdominal blood vessels for laparoscopic gastrectomy. In gastrectomy, it is very important to understand branching structure of abdominal arteries and veins, which feed and drain specific abdominal organs including the stomach, the liver and the pancreas. In the real clinical stage, a surgeon creates a diagnostic report of the patient anatomy. This report summarizes the branching patterns of the blood vessels related to the stomach. The surgeon decides actual operative procedure. This paper shows an automated method to generate a branching pattern report for abdominal blood vessels based on automated anatomical labeling. The report contains 3D rendering showing important blood vessels and descriptions of branching patterns of each vessel. We have applied this method for fifty cases of 3D abdominal CT scans and confirmed the proposed method can automatically generate branching pattern reports of abdominal arteries.

  13. Characteristic flow patterns generated by macrozoobenthic structures

    NASA Astrophysics Data System (ADS)

    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

  14. Developing Linguistic Auditory Memory Patterns.

    ERIC Educational Resources Information Center

    Valett, Robert E.

    1983-01-01

    For learning handicapped children with impaired language associations, patterns, and expressions, this paper summarizes relevant linguistic research and instructional strategies. Linguistic auditory memory pattern exercises and examples are then presented as an integrated multisensory approach which has been found useful by special educators.…

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

    PubMed

    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.

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

    PubMed Central

    Guertin, Pierre A.

    2013-01-01

    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. PMID:23403923

  17. From Central Pattern Generator to Sensory Template in the Evolution of Birdsong

    ERIC Educational Resources Information Center

    Konishi, Masakazu

    2010-01-01

    Central nervous networks, be they a part of the human brain or a group of neurons in a snail, may be designed to produce distinct patterns of movement. Central pattern generators can account for the development and production of normal vocal signals without auditory feedback in non-songbirds. Songbirds need auditory feedback to develop and…

  18. Contextual modulation of a multifunctional central pattern generator.

    PubMed

    Ramakrishnan, Siddharth; Arnett, Bridgette; Murphy, A Don

    2014-11-01

    The multifunctional buccal central pattern generator in snails, which controls different oral behaviors, has been well characterized. In this work we propose a role for the group of about 40 electrotonically coupled buccal A cluster cells as a context-dependant switch for the buccal central pattern generator, modulating motor patterns that elicit different oral behaviors. We characterize these cells based on location and morphology, and provide evidence for their selective activation under two different stimuli - Listerine perfusion and intestinal nerve stimulation - triggering buccal motor patterns putatively underlying egestion and substrate cleaning. A new role for these electrotonically coupled buccal A cluster neurons is shown. They serve as a context-dependant switch that alters buccal motor patterns depending on input stimuli, thereby eliciting the appropriate behavioral response.

  19. Monolingual and Bilingual Development Patterns.

    ERIC Educational Resources Information Center

    Johnson, Teresa H.

    Similarities and differences in language acquisition and variations in patterns of language dominance were studied with three four-year-old girls. The ideoqraphic study of child speech involved a monolingual English-speaking child, a monolingual Spanish-speaking child, and a bilingual English-Spanish-speaking child. The following measures were…

  20. Computer Generated Holography with Intensity-Graded Patterns

    PubMed Central

    Conti, Rossella; Assayag, Osnath; de Sars, Vincent; Guillon, Marc; Emiliani, Valentina

    2016-01-01

    Computer Generated Holography achieves patterned illumination at the sample plane through phase modulation of the laser beam at the objective back aperture. This is obtained by using liquid crystal-based spatial light modulators (LC-SLMs), which modulate the spatial phase of the incident laser beam. A variety of algorithms is employed to calculate the phase modulation masks addressed to the LC-SLM. These algorithms range from simple gratings-and-lenses to generate multiple diffraction-limited spots, to iterative Fourier-transform algorithms capable of generating arbitrary illumination shapes perfectly tailored on the base of the target contour. Applications for holographic light patterning include multi-trap optical tweezers, patterned voltage imaging and optical control of neuronal excitation using uncaging or optogenetics. These past implementations of computer generated holography used binary input profile to generate binary light distribution at the sample plane. Here we demonstrate that using graded input sources, enables generating intensity graded light patterns and extend the range of application of holographic light illumination. At first, we use intensity-graded holograms to compensate for LC-SLM position dependent diffraction efficiency or sample fluorescence inhomogeneity. Finally we show that intensity-graded holography can be used to equalize photo evoked currents from cells expressing different levels of chanelrhodopsin2 (ChR2), one of the most commonly used optogenetics light gated channels, taking into account the non-linear dependence of channel opening on incident light. PMID:27799896

  1. Teaching Design Patterns through Computer Game Development

    ERIC Educational Resources Information Center

    Gestwicki, Paul; Sun, Fu-Shing

    2008-01-01

    We present an approach for teaching design patterns that emphasizes object-orientation and patterns integration. The context of computer game development is used to engage and motivate students, and it is additionally rich with design patterns. A case study is presented based on "EEClone," an arcade-style computer game implemented in Java. Our…

  2. Digitally based pattern generator for an electron-beam welder

    SciTech Connect

    Whitten, L.G. III

    1981-02-19

    A digitally based deflection generator for an electron-beam welder is presented. Up to seven patterns of any shape are stored in programmable read-only memory (PROM). The pattern resolution is 39% at frequencies from 10 Hz to 1 kHz and can be x-t, y-t, or x-y formed. Frequency and pattern selections may be chosen by the welder computer or manually selected on the front panel. The ability to repeatedly synchronize two waveforms of any shape and frequency enables an unlimited variety of welds.

  3. Ring Counter Based ATPG for Low Transition Test Pattern Generation

    PubMed Central

    Begam, V. M. Thoulath; Baulkani, S.

    2015-01-01

    In test mode test patterns are applied in random fashion to the circuit under circuit. This increases switching transition between the consecutive test patterns and thereby increases dynamic power dissipation. The proposed ring counter based ATPG reduces vertical switching transitions by inserting test vectors only between the less correlative test patterns. This paper presents the RC-ATPG with an external circuit. The external circuit consists of XOR gates, full adders, and multiplexers. First the total number of transitions between the consecutive test patterns is determined. If it is more, then the external circuit generates and inserts test vectors in between the two test patterns. Test vector insertion increases the correlation between the test patterns and reduces dynamic power dissipation. The results prove that the test patterns generated by the proposed ATPG have fewer transitions than the conventional ATPG. Experimental results based on ISCAS'85 and ISCAS'89 benchmark circuits show 38.5% reduction in the average power and 50% reduction in the peak power attained during testing with a small size decoding logic. PMID:26075295

  4. Central pattern generator for vocalization: Is there a vertebrate morphotype?

    PubMed Central

    Bass, Andrew H.

    2014-01-01

    Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one’s own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems. PMID:25050813

  5. The Network Spinal Wave as a Central Pattern Generator

    PubMed Central

    Epstein, Donald M.; Lemberger, Daniel

    2016-01-01

    Abstract Objectives: This article explains the research on a unique spinal wave visibly observed in association with network spinal analysis care. Since 1997, the network wave has been studied using surface electromyography (sEMG), characterized mathematically, and determined to be a unique and repeatable phenomenon. Methods: The authors provide a narrative review of the research and a context for the network wave's development. Results: The sEMG research demonstrates that the movement of the musculature of the spine during the wave phenomenon is electromagnetic and mechanical. The changes running along the spine were characterized mathematically at three distinct levels of care. Additionally, the wave has the mathematical properties of a central pattern generator (CPG). Conclusions: The network wave may be the first CPG discovered in the spine unrelated to locomotion. The mathematical characterization of the signal also demonstrates coherence at a distance between the sacral to cervical spine. According to mathematical engineers, based on studies conducted a decade apart, the wave itself is a robust phenomenon and the detection methods for this coherence may represent a new measure for central nervous system health. This phenomenon has implications for recovery from spinal cord injury and for reorganizational healing development. PMID:27243963

  6. Distinct signals generate repeating striped pattern in the embryonic parasegment.

    PubMed

    Hatini, V; DiNardo, S

    2001-01-01

    How repeating striped patterns arise across cellular fields is unclear. To address this we examined the repeating pattern of Stripe (Sr) expression across the parasegment (PS) in Drosophila. This pattern is generated in two steps. First, the ligands Hedgehog (Hh) and Wingless (Wg) subdivide the PS into smaller territories. Second, the ligands Hh, Spitz (Spi), and Wg each emanate from a specific territory and induce Sr expression in an adjacent territory. We also show that the width of Sr expression is determined by signaling strength. Finally, an enhancer trap in the sr gene detects the response to Spi and Wg, but not to Hh, implying the existence of separable control elements in the sr gene. Thus, a distinct inductive event is used to initiate each element of the repeating striped pattern.

  7. Computer program for automatic generation of BWR control rod patterns

    SciTech Connect

    Taner, M.S.; Levine, S.H.; Hsia, M.Y. )

    1990-01-01

    A computer program named OCTOPUS has been developed to automatically determine a control rod pattern that approximates some desired target power distribution as closely as possible without violating any thermal safety or reactor criticality constraints. The program OCTOPUS performs a semi-optimization task based on the method of approximation programming (MAP) to develop control rod patterns. The SIMULATE-E code is used to determine the nucleonic characteristics of the reactor core state.

  8. Mortality patterns in developed countries.

    PubMed

    Manton, K G

    1984-01-01

    The implications of recent demographic trends in developed countries are considered. The emphasis is on the increase in life expectancy, and particularly in the rate of growth of the numbers of the very old (those aged 85 and over). "To evaluate the impact of recent mortality reductions on the social security and health service systems of developed countries [the author analyzes] the mortality conditions of 11 developed countries over the period 1950 to 1978." The countries concerned are the United States, Canada, Japan, Norway, Sweden, Denmark, Czechoslovakia, Hungary, the United Kingdom, the Federal Republic of Germany, and France. "The results of [the] analyses show that major increases in life expectancy have occurred at advanced ages for females and that the cross-country differences in the cause of death structure indicate that advances were achieved through a variety of mechanisms. Thus, it appears that no single uniform model of biological aging will currently explain cause specific mortality trends in countries with historically high life expectancies. This implies that further mortality reductions are possible in these countries by achieving cause specific mortality reductions observed to have occurred in another country." This is a revised version of a paper originally presented at the 1983 Annual Meeting of the Population Association of America (see Population Index, Vol. 49, No. 3, Fall 1983, p. 413). PMID:12340261

  9. Electronic Tongue Generating Continuous Recognition Patterns for Protein Analysis

    PubMed Central

    Hou, Yanxia; Genua, Maria; Garçon, Laurie-Amandine; Buhot, Arnaud; Calemczuk, Roberto; Bonnaffé, David; Lortat-Jacob, Hugues; Livache, Thierry

    2014-01-01

    In current protocol, a combinatorial approach has been developed to simplify the design and production of sensing materials for the construction of electronic tongues (eT) for protein analysis. By mixing a small number of simple and easily accessible molecules with different physicochemical properties, used as building blocks (BBs), in varying and controlled proportions and allowing the mixtures to self-assemble on the gold surface of a prism, an array of combinatorial surfaces featuring appropriate properties for protein sensing was created. In this way, a great number of cross-reactive receptors can be rapidly and efficiently obtained. By combining such an array of combinatorial cross-reactive receptors (CoCRRs) with an optical detection system such as surface plasmon resonance imaging (SPRi), the obtained eT can monitor the binding events in real-time and generate continuous recognition patterns including 2D continuous evolution profile (CEP) and 3D continuous evolution landscape (CEL) for samples in liquid. Such an eT system is efficient for discrimination of common purified proteins. PMID:25286325

  10. Neural Sequence Generation Using Spatiotemporal Patterns of Inhibition

    PubMed Central

    Cannon, Jonathan; Kopell, Nancy; Gardner, Timothy; Markowitz, Jeffrey

    2015-01-01

    Stereotyped sequences of neural activity are thought to underlie reproducible behaviors and cognitive processes ranging from memory recall to arm movement. One of the most prominent theoretical models of neural sequence generation is the synfire chain, in which pulses of synchronized spiking activity propagate robustly along a chain of cells connected by highly redundant feedforward excitation. But recent experimental observations in the avian song production pathway during song generation have shown excitatory activity interacting strongly with the firing patterns of inhibitory neurons, suggesting a process of sequence generation more complex than feedforward excitation. Here we propose a model of sequence generation inspired by these observations in which a pulse travels along a spatially recurrent excitatory chain, passing repeatedly through zones of local feedback inhibition. In this model, synchrony and robust timing are maintained not through redundant excitatory connections, but rather through the interaction between the pulse and the spatiotemporal pattern of inhibition that it creates as it circulates the network. These results suggest that spatially and temporally structured inhibition may play a key role in sequence generation. PMID:26536029

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

    PubMed Central

    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 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

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

    PubMed

    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

  13. Override of spontaneous respiratory pattern generator reduces cardiovascular parasympathetic influence

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Vallurupalli, S.; Evans, J. M.; Bruce, E. N.; Knapp, C. F.

    1995-01-01

    We investigated the effects of voluntary control of breathing on autonomic function in cardiovascular regulation. Variability in heart rate was compared between 5 min of spontaneous and controlled breathing. During controlled breathing, for 5 min, subjects voluntarily reproduced their own spontaneous breathing pattern (both rate and volume on a breath-by-breath basis). With the use of this experimental design, we could unmask the effects of voluntary override of the spontaneous respiratory pattern generator on autonomic function in cardiovascular regulation without the confounding effects of altered respiratory pattern. Results from 10 subjects showed that during voluntary control of breathing, mean values of heart rate and blood pressure increased, whereas fractal and spectral powers in heart rate in the respiratory frequency region decreased. End-tidal PCO2 was similar during spontaneous and controlled breathing. These results indicate that the act of voluntary control of breathing decreases the influence of the vagal component, which is the principal parasympathetic influence in cardiovascular regulation.

  14. Global Software Development Patterns for Project Management

    NASA Astrophysics Data System (ADS)

    Välimäki, Antti; Kääriäinen, Jukka; Koskimies, Kai

    Global software development with the agile or waterfall development process has been taken into use in many companies. GSD offers benefits but also new challenges without known, documented solutions. The goal of this research is to present current best practices for GSD in the form of process patterns for project management, evaluated by using a scenario-based assessment method. The best practices have been collected from a large company operating in process automation. It is expected that the resulting pattern language helps other companies to improve their GSD processes by incorporating the patterns in the processes.

  15. Pattern Recognition on Read Positioning in Next Generation Sequencing

    PubMed Central

    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

  16. Stochastic Generation of Wind Patterns over Lake Geneva

    NASA Astrophysics Data System (ADS)

    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.

  17. Temperature-Dependent Regulation of Vocal Pattern Generator

    PubMed Central

    Yamaguchi, Ayako; Gooler, David; Herrold, Amy; Patel, Shailja; Pong, Winnie W.

    2008-01-01

    Vocalizations of Xenopus laevis are generated by central pattern generators (CPGs). The advertisement call of male X. laevis is a complex biphasic motor rhythm consisting of fast and slow trills (a train of clicks). We found that the trill rate of these advertisement calls is sensitive to temperature and that this rate modification of the vocal rhythms originates in the central pattern generators. In vivo the rates of fast and slow trills increased linearly with an increase in temperature. In vitro a similar linear relation between temperature and compound action potential frequency in the laryngeal nerve was found when fictive advertisement calls were evoked in the isolated brain. Temperature did not limit the contractile properties of laryngeal muscles within the frequency range of vocalizations. We next took advantage of the temperature sensitivity of the vocal CPG in vitro to localize the source of the vocal rhythms. We focused on the dorsal tegmental area of the medulla (DTAM), a brain stem nucleus that is essential for vocal production. We found that bilateral cooling of DTAM reduced both fast and slow trill rates. Thus we conclude that DTAM is a source of biphasic vocal rhythms. PMID:18829853

  18. Evolution of central pattern generators and rhythmic behaviours.

    PubMed

    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.

  19. Temperature-dependent regulation of vocal pattern generator.

    PubMed

    Yamaguchi, Ayako; Gooler, David; Herrold, Amy; Patel, Shailja; Pong, Winnie W

    2008-12-01

    Vocalizations of Xenopus laevis are generated by central pattern generators (CPGs). The advertisement call of male X. laevis is a complex biphasic motor rhythm consisting of fast and slow trills (a train of clicks). We found that the trill rate of these advertisement calls is sensitive to temperature and that this rate modification of the vocal rhythms originates in the central pattern generators. In vivo the rates of fast and slow trills increased linearly with an increase in temperature. In vitro a similar linear relation between temperature and compound action potential frequency in the laryngeal nerve was found when fictive advertisement calls were evoked in the isolated brain. Temperature did not limit the contractile properties of laryngeal muscles within the frequency range of vocalizations. We next took advantage of the temperature sensitivity of the vocal CPG in vitro to localize the source of the vocal rhythms. We focused on the dorsal tegmental area of the medulla (DTAM), a brain stem nucleus that is essential for vocal production. We found that bilateral cooling of DTAM reduced both fast and slow trill rates. Thus we conclude that DTAM is a source of biphasic vocal rhythms. PMID:18829853

  20. Second harmonic generation in a low-loss orientation-patterned GaAs waveguide.

    PubMed

    Fedorova, K A; McRobbie, A D; Sokolovskii, G S; Schunemann, P G; Rafailov, E U

    2013-07-15

    The technology of low-loss orientation-patterned gallium arsenide (OP-GaAs) waveguided crystals was developed and realized by reduction of diffraction scattering on the waveguide pattern. The propagation losses in the OP-GaAs waveguide were estimated to be as low as 2.1 dB/cm, thus demonstrating the efficient second harmonic generation at 1621 nm under an external pumping.

  1. Item Generation for Test Development [Book Review].

    ERIC Educational Resources Information Center

    Papanastasiou, Elena C.

    2003-01-01

    This volume, based on papers presented at a 1998 conference, collects thinking and research on item generation for test development. It includes materials on psychometric and cognitive theory, construct-oriented approaches to item generation, the item generation process, and some applications of item generative principles. (SLD)

  2. Symmetry in locomotor central pattern generators and animal gaits

    NASA Astrophysics Data System (ADS)

    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.

  3. Sequentially firing neurons confer flexible timing in neural pattern generators

    SciTech Connect

    Urban, Alexander; Ermentrout, Bard

    2011-05-15

    Neuronal networks exhibit a variety of complex spatiotemporal patterns that include sequential activity, synchrony, and wavelike dynamics. Inhibition is the primary means through which such patterns are implemented. This behavior is dependent on both the intrinsic dynamics of the individual neurons as well as the connectivity patterns. Many neural circuits consist of networks of smaller subcircuits (motifs) that are coupled together to form the larger system. In this paper, we consider a particularly simple motif, comprising purely inhibitory interactions, which generates sequential periodic dynamics. We first describe the dynamics of the single motif both for general balanced coupling (all cells receive the same number and strength of inputs) and then for a specific class of balanced networks: circulant systems. We couple these motifs together to form larger networks. We use the theory of weak coupling to derive phase models which, themselves, have a certain structure and symmetry. We show that this structure endows the coupled system with the ability to produce arbitrary timing relationships between symmetrically coupled motifs and that the phase relationships are robust over a wide range of frequencies. The theory is applicable to many other systems in biology and physics.

  4. Note: A novel dielectric barrier discharge system for generating stable patterns in wide range

    NASA Astrophysics Data System (ADS)

    Liu, Weibo; Wang, Yongjie; Zhang, Hao; Pan, Yuyang; Dong, Lifang

    2016-05-01

    We develop a novel dielectric barrier discharge (DBD) system with a meshed water electrode to generate stable square superlattice patterns (MSSP) in Ar/air mixture in a wide range of experimental environments. Discharge scenarios with the applied voltage increasing in the meshed DBD and ordinary DBD are presented respectively under the same experimental conditions. It is found that a square pattern and MSSP can be obtained stably and easily in meshed DBD, while no pattern emerges in ordinary DBD. MSSP can be formed when the Ar content is from 0% to 70%, and the corresponding applied voltage decreases with Ar content increasing. Results based on optical methods show that MSSP is generated by artificially designed electrodes together with nonlinear characteristics of DBD, which may account for why patterns in meshed DBD exist in a wide range.

  5. Using pattern enumeration to accelerate process development and ramp yield

    NASA Astrophysics Data System (ADS)

    Zhuang, Linda; Pang, Jenny; Xu, Jessy; Tsai, Mengfeng; Wang, Amy; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

    2016-03-01

    During a new technology node process setup phase, foundries do not initially have enough product chip designs to conduct exhaustive process development. Different operational teams use manually designed simple test keys to set up their process flows and recipes. When the very first version of the design rule manual (DRM) is ready, foundries enter the process development phase where new experiment design data is manually created based on these design rules. However, these IP/test keys contain very uniform or simple design structures. This kind of design normally does not contain critical design structures or process unfriendly design patterns that pass design rule checks but are found to be less manufacturable. It is desired to have a method to generate exhaustive test patterns allowed by design rules at development stage to verify the gap of design rule and process. This paper presents a novel method of how to generate test key patterns which contain known problematic patterns as well as any constructs which designers could possibly draw based on current design rules. The enumerated test key patterns will contain the most critical design structures which are allowed by any particular design rule. A layout profiling method is used to do design chip analysis in order to find potential weak points on new incoming products so fab can take preemptive action to avoid yield loss. It can be achieved by comparing different products and leveraging the knowledge learned from previous manufactured chips to find possible yield detractors.

  6. National Development Generates National Identities.

    PubMed

    Golob, Tea; Makarovič, Matej; Suklan, Jana

    2016-01-01

    The purpose of the article is to test the relationship between national identities and modernisation. We test the hypotheses that not all forms of identity are equally compatible with modernisation as measured by Human Development Index. The less developed societies are characterised by strong ascribed national identities based on birth, territory and religion, but also by strong voluntarist identities based on civic features selected and/or achieved by an individual. While the former decreases with further modernisation, the latter may either decrease or remain at high levels and coexist with instrumental supranational identifications, typical for the most developed countries. The results, which are also confirmed by multilevel regression models, thus demonstrate that increasing modernisation in terms of development contributes to the shifts from classical, especially ascribed, identities towards instrumental identifications. These findings are particularly relevant in the turbulent times increasingly dominated by the hardly predictable effects of the recent mass migrations. PMID:26841050

  7. National Development Generates National Identities

    PubMed Central

    2016-01-01

    The purpose of the article is to test the relationship between national identities and modernisation. We test the hypotheses that not all forms of identity are equally compatible with modernisation as measured by Human Development Index. The less developed societies are characterised by strong ascribed national identities based on birth, territory and religion, but also by strong voluntarist identities based on civic features selected and/or achieved by an individual. While the former decreases with further modernisation, the latter may either decrease or remain at high levels and coexist with instrumental supranational identifications, typical for the most developed countries. The results, which are also confirmed by multilevel regression models, thus demonstrate that increasing modernisation in terms of development contributes to the shifts from classical, especially ascribed, identities towards instrumental identifications. These findings are particularly relevant in the turbulent times increasingly dominated by the hardly predictable effects of the recent mass migrations. PMID:26841050

  8. Implementation and characterization of a DUV raster-scanned mask pattern generation system

    NASA Astrophysics Data System (ADS)

    Bohan, Michael J.; Hamaker, Henry Chris; Montgomery, Warren

    2002-03-01

    Etec Systems, Inc., an Applied Materials company, has completed the implementation and characterization of a deep ultraviolet (DUV), multibeam, raster-scanned mask patterning and integrated process solution. The ALTA® 4000 mask pattern generation system integrates a new data path, environmental control system, DUV optics, a 257nm DUV continuous-wave laser source, and an environmentally stable chemically amplified resist (CAR) process to deliver superior productivity, improved resolution, and critical dimension (CD) control required for volume 130nm mask production. Additionally, to obtain the maximum benefit of this mask pattern generation system, Etec has completed development of an environmentally stable CAR process, which has been tailored to allow the maskmaking industry to continue to receive pre-coated mask blanks from commercial suppliers. This paper details the system architecture and presents system performance and characterization data. The characterization results of the integrated system and process solution are also presented. This integrated pattern generation and process solution continues the tradition of the production workhorse ALTA product line with the introduction of the ALTA 4000 scanned-laser mask pattern generation system.

  9. The generation of antiphase oscillations and synchrony by a rebound-based vertebrate central pattern generator.

    PubMed

    Li, Wen-Chang; Merrison-Hort, Robert; Zhang, Hong-Yan; Borisyuk, Roman

    2014-04-23

    Many neural circuits are capable of generating multiple stereotyped outputs after different sensory inputs or neuromodulation. We have previously identified the central pattern generator (CPG) for Xenopus tadpole swimming that involves antiphase oscillations of activity between the left and right sides. Here we analyze the cellular basis for spontaneous left-right motor synchrony characterized by simultaneous bursting on both sides at twice the swimming frequency. Spontaneous synchrony bouts are rare in most tadpoles, and they instantly emerge from and switch back to swimming, most frequently within the first second after skin stimulation. Analyses show that only neurons that are active during swimming fire action potentials in synchrony, suggesting both output patterns derive from the same neural circuit. The firing of excitatory descending interneurons (dINs) leads that of other types of neurons in synchrony as it does in swimming. During synchrony, the time window between phasic excitation and inhibition is 7.9 ± 1 ms, shorter than that in swimming (41 ± 2.3 ms). The occasional, extra midcycle firing of dINs during swimming may initiate synchrony, and mismatches of timing in the left and right activity can switch synchrony back to swimming. Computer modeling supports these findings by showing that the same neural network, in which reciprocal inhibition mediates rebound firing, can generate both swimming and synchrony without circuit reconfiguration. Modeling also shows that lengthening the time window between phasic excitation and inhibition by increasing dIN synaptic/conduction delay can improve the stability of synchrony.

  10. Synergistic action of nectins and cadherins generates the mosaic cellular pattern of the olfactory epithelium

    PubMed Central

    Katsunuma, Sayaka; Honda, Hisao; Shinoda, Tomoyasu; Ishimoto, Yukitaka; Miyata, Takaki; Kiyonari, Hiroshi; Abe, Takaya; Nibu, Ken-ichi; Takai, Yoshimi

    2016-01-01

    In the olfactory epithelium (OE), olfactory cells (OCs) and supporting cells (SCs), which express different cadherins, are arranged in a characteristic mosaic pattern in which OCs are enclosed by SCs. However, the mechanism underlying this cellular patterning is unclear. Here, we show that the cellular pattern of the OE is established by cellular rearrangements during development. In the OE, OCs express nectin-2 and N-cadherin, and SCs express nectin-2, nectin-3, E-cadherin, and N-cadherin. Heterophilic trans-interaction between nectin-2 on OCs and nectin-3 on SCs preferentially recruits cadherin via α-catenin to heterotypic junctions, and the differential distributions of cadherins between junctions promote cellular intercalations, resulting in the formation of the mosaic pattern. These observations are confirmed by model cell systems, and various cellular patterns are generated by the combinatorial expression of nectins and cadherins. Collectively, the synergistic action of nectins and cadherins generates mosaic pattern, which cannot be achieved by a single mechanism. PMID:26929452

  11. Fus Expression Patterns in Developing Tooth

    PubMed Central

    Kim, Eun-Jung; Lee, Jong-Min; Jung, Han-Sung

    2013-01-01

    Recently, the RNA/DNA-binding protein FUS, Fused in sarcoma, was shown to play a role in growth, differentiation, and morphogenesis in vertebrates. Because little is known about Fus, we investigated its expression pattern in murine tooth development. In situ hybridization of mouse mandibles at specific developmental stages was performed with a DIG-labeled RNA probe. During early tooth development, Fus was detected in the dental epithelium and dental mesenchyme at 11 days postcoitum (dpc) and 12 dpc. From 14 dpc, Fus was strongly expressed in the dental papilla and the cervical loop of the dental epithelium. At postnatal day 4 (PN4), Fus expression was observed in the odontoblasts, ameloblasts, the proliferation zone of the pulp, and the cervical loop. At PN14, the expression pattern of Fus was found to be maintained in the odontoblasts and the proliferation zone of the pulp. Furthermore, Fus expression was especially strong in the Hertwig’s epithelial root sheath (HERS). Therefore, this study suggests that Fus may play a role in the HERS during root development. PMID:25949136

  12. Pattern Generator for Bench Test of Digital Boards

    NASA Technical Reports Server (NTRS)

    Berkun, Andrew C.; Chu, Anhua J.

    2012-01-01

    All efforts to develop electronic equipment reach a stage where they need a board test station for each board. The SMAP digital system consists of three board types that interact with each other using interfaces with critical timing. Each board needs to be tested individually before combining into the integrated digital electronics system. Each board needs critical timing signals from the others to be able to operate. A bench test system was developed to support test of each board. The test system produces all the outputs of the control and timing unit, and is delivered much earlier than the timing unit. Timing signals are treated as data. A large file is generated containing the state of every timing signal at any instant. This file is streamed out to an IO card, which is wired directly to the device-under-test (DUT) input pins. This provides a flexible test environment that can be adapted to any of the boards required to test in a standalone configuration. The problem of generating the critical timing signals is then transferred from a hardware problem to a software problem where it is more easily dealt with.

  13. Developments of terahertz wave generation technologies

    NASA Astrophysics Data System (ADS)

    Suto, Ken; Nishizawa, Jun-Ichi

    2004-05-01

    Recent developments of terahertz wave generation devices utilizing lattice and molecular vibration are introduced. They are semiconductor Raman laser and amplifier, parametric generation of terahertz wave using phonon-polaritons in semiconductors and dielectrics, together with electronic devices: TUNNETT diode and ISIT. Future important applications will be in the field of medicine, biology, and pharmacy.

  14. Patterning and cell fate in ear development.

    PubMed

    Alsina, Berta; Giraldez, Fernando; Pujades, Cristina

    2009-01-01

    The inner ear is a complex structure responsible for the senses of audition and balance in vertebrates. The ear is organised into different sense organs that are specialised to detect specific stimuli such as sound and linear or angular accelerations. The elementary sensory unit of the ear consists of hair cells, supporting cells, neurons and Schwann cells. Hair cells are the mechano-electrical transducing elements, and otic neurons convey information coded in electrical impulses to the brain. With the exception of the Schwann cells, all cellular elements of the inner ear derive from the otic placode. This is an ectodermal thickening that is specified in the head ectoderm adjacent to the caudal hindbrain. The complex organisation of the ear requires precise coupling of regional specification and cell fate decisions during development, i.e. specificity in defining particular spatial domains containing particular cell types. Those decisions are taken early in development and are the subject of this article. We review here recent work on: i) early patterning of the otic placode, ii) the role of neural tube signals in the patterning of the otic vesicle, and iii) the genes underlying cell fate determination of neurons and sensory hair cells.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    developing downstream a straight single channel reach; and c) branches in sinuous-second order lateral channels. Velocity maps and an analysis of secondary currents provide information on the three-dimensional flows of water within the channel indicating that bed and channel morphology affect hydraulic characteristics. Several cross sections present unusually deep pools up to ~80m depth in the outer bank and significant increases in the local water slope. These are related to geological constraints, which manifest in the over deepening from the preferentially downwards secondary flow, exacerbating erosion. The anabranching patterns in large rivers such as the Madeira are not just controlled by intrinsic morphodynamics and hydraulic geometry variables but though a variety of interactions with the architecture of the floodplain and the control exerted by older fluvial geomorphological units.

  16. Positive Selection Linked with Generation of Novel Mammalian Dentition Patterns.

    PubMed

    Machado, João Paulo; Philip, Siby; Maldonado, Emanuel; O'Brien, Stephen J; Johnson, Warren E; Antunes, Agostinho

    2016-01-01

    A diverse group of genes are involved in the tooth development of mammals. Several studies, focused mainly on mice and rats, have provided a detailed depiction of the processes coordinating tooth formation and shape. Here we surveyed 236 tooth-associated genes in 39 mammalian genomes and tested for signatures of selection to assess patterns of molecular adaptation in genes regulating mammalian dentition. Of the 236 genes, 31 (∼13.1%) showed strong signatures of positive selection that may be responsible for the phenotypic diversity observed in mammalian dentition. Mammalian-specific tooth-associated genes had accelerated mutation rates compared with older genes found across all vertebrates. More recently evolved genes had fewer interactions (either genetic or physical), were associated with fewer Gene Ontology terms and had faster evolutionary rates compared with older genes. The introns of these positively selected genes also exhibited accelerated evolutionary rates, which may reflect additional adaptive pressure in the intronic regions that are associated with regulatory processes that influence tooth-gene networks. The positively selected genes were mainly involved in processes like mineralization and structural organization of tooth specific tissues such as enamel and dentin. Of the 236 analyzed genes, 12 mammalian-specific genes (younger genes) provided insights on diversification of mammalian teeth as they have higher evolutionary rates and exhibit different expression profiles compared with older genes. Our results suggest that the evolution and development of mammalian dentition occurred in part through positive selection acting on genes that previously had other functions. PMID:27613398

  17. Positive Selection Linked with Generation of Novel Mammalian Dentition Patterns.

    PubMed

    Machado, João Paulo; Philip, Siby; Maldonado, Emanuel; O'Brien, Stephen J; Johnson, Warren E; Antunes, Agostinho

    2016-09-11

    A diverse group of genes are involved in the tooth development of mammals. Several studies, focused mainly on mice and rats, have provided a detailed depiction of the processes coordinating tooth formation and shape. Here we surveyed 236 tooth-associated genes in 39 mammalian genomes and tested for signatures of selection to assess patterns of molecular adaptation in genes regulating mammalian dentition. Of the 236 genes, 31 (∼13.1%) showed strong signatures of positive selection that may be responsible for the phenotypic diversity observed in mammalian dentition. Mammalian-specific tooth-associated genes had accelerated mutation rates compared with older genes found across all vertebrates. More recently evolved genes had fewer interactions (either genetic or physical), were associated with fewer Gene Ontology terms and had faster evolutionary rates compared with older genes. The introns of these positively selected genes also exhibited accelerated evolutionary rates, which may reflect additional adaptive pressure in the intronic regions that are associated with regulatory processes that influence tooth-gene networks. The positively selected genes were mainly involved in processes like mineralization and structural organization of tooth specific tissues such as enamel and dentin. Of the 236 analyzed genes, 12 mammalian-specific genes (younger genes) provided insights on diversification of mammalian teeth as they have higher evolutionary rates and exhibit different expression profiles compared with older genes. Our results suggest that the evolution and development of mammalian dentition occurred in part through positive selection acting on genes that previously had other functions.

  18. Compact neutron generator development at LBNL

    SciTech Connect

    Reijonen, J.; English, G.; Firestone, R.; Giquel, F.; King, M.; Leung, K-N.; Sun, M.

    2003-12-31

    A wide variety of applications ranging from medical (BNCT, Boron Neutron Capture Therapy) and basic science (neutron imaging, material studies) to homeland security (explosive detection and nuclear material non-proliferation) are in need of compact, high flux neutron generators. The Plasma and Ion Source Technology Group in the Lawrence Berkeley National Laboratory is developing various neutron generators for these applications. These neutron generators employed either the D-D or the D-T fusion reaction for the neutron production. The deuterium or deuterium-tritium gas mixture is ionized in an RF-driven plasma source. The ions are then accelerated to {approx}100 keV energy using high current, high voltage DC-power supply to a target where the 2.45 MeV (for D-D reaction) or 14 MeV (for the D-T reaction) neutrons are generated. The development of two different types of neutron tubes are being discussed in this presentation, namely compact, pulsed operation neutron generators and cw, high yield neutron generators. These generators are currently operating at D-D neutron yields of 108 n/s and 109 n/s respectively. A facility, incorporating the larger neutron generator, has been constructed for Prompt Gamma Activation Analysis (PGAA) and Neutron Activation Analysis (NAA) measurements.

  19. A rule-based expert system for automatic control rod pattern generation for boiling water reactors

    SciTech Connect

    Lin, L.S.; Lin, C. )

    1991-07-01

    This paper reports on an expert system for generating control rod patterns that has been developed. The knowledge is transformed into IF-THEN rules. The inference engine uses the Rete pattern matching algorithm to match facts, and rule premises and conflict resolution strategies to make the system function intelligently. A forward-chaining mechanism is adopted in the inference engine. The system is implemented in the Common Lisp programming language. The three-dimensional core simulation model performs the core status and burnup calculations. The system is successfully demonstrated by generating control rod programming for the 2894-MW (thermal) Kuosheng nuclear power plant in Taiwan. The computing time is tremendously reduced compared to programs using mathematical methods.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Fourth-generation photovoltaic concentrator system development

    SciTech Connect

    O`Neill, M.J.; McDanal, A.J.

    1995-10-01

    In 1991, under a contract with Sandia for the Concentrator Initiative, the ENTECH team initiated the design and development of a fourth-generation concentrator module. In 1992, Sandia also contracted with ENTECH to develop a new control and drive system for the ENTECH array. This report documents the design and development work performed under both contracts. Manufacturing processes for the new module were developed at the same time under a complementary PVMaT contract with the National Renewable Energy Laboratory. Two 100-kW power plants were deployed in 1995 in Texas using the newly developed fourth-generation concentrator technology, one at the CSW Solar Park near Ft. Davis and one at TUE Energy Park in Dallas. Technology developed under the Sandia contracts has made a successful transition from the laboratory to the production line to the field.

  2. Patterns of performance development in elite athletes.

    PubMed

    Gulbin, Jason; Weissensteiner, Juanita; Oldenziel, Karen; Gagné, Françoys

    2013-01-01

    This investigation sought to contrast generalised models of athlete development with the specific pathway trajectories and transitions experienced by 256 elite athletes across 27 different sports. All participants completed the National Athlete Development Survey and within it, the Athlete Development Triangle featuring the differentiation of junior and senior competition experience and progression. Developmental initiation; prevalence, magnitude and direction of pathway trajectory; extent of concurrent junior and senior competitive experience; and variability between sports were examined. Three major trajectories were identified in relation to athlete transition from Nil competition to Elite competition, via junior and senior competition phases. These included Pure ascent (16.4%), Mixed ascent (26.2%) and Mixed descent (57.4%). These were further partitioned into eight sub-trajectories, demonstrating a mix of linear, crossover and concurrent competition profiles. Substantial variability with regard to starting age, pattern of ascent and magnitude of transition was apparent. Non-linear trajectories were experienced by the majority of athletes (83.6%), with pure junior to senior developmental linearity evident in less than 7% of cases. Athletes in cgs sports (those measured in centimetres, grams or seconds) were less likely (43%) to experience a descending trajectory in comparison with non-cgs athletes (70%; p<0.001). The collective findings of this investigation demonstrate that, contrary to the popular pyramidal concept of athlete development, a single linear assault on expertise is rare, and that the common normative junior to senior competition transition is mostly characterised by complex oscillations featuring highly varied transitions. More developmental 'granularity' is needed to advance our understanding of sport expertise.

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

    PubMed

    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

  4. Association of spectral development patterns with development stages of corn

    NASA Technical Reports Server (NTRS)

    Crist, E. P. (Principal Investigator)

    1982-01-01

    Association is made between the development stages of corn as defined by Hanway and the temporal-spectral development pattern of corn in a transformed data space derived from Landsat-MSS band reflectance values, using field-collected reflectance and associated data. Results indicate that the spectral vegetation index used (a reflectance equivalent of Tasseled Cap Greenness) reaches a maximum well before the stage at which corn is expected to achieve its peak leaf area index. Possible physiological and canopy geometry related causes for this and other results are presented.

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

    PubMed Central

    Noh, Yun Hong; Jeong, Do Un

    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 graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  6. Implementation of a data packet generator using pattern matching for wearable ECG monitoring systems.

    PubMed

    Noh, Yun Hong; Jeong, Do Un

    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 graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  7. Compact neutron generator developement and applications

    SciTech Connect

    Leung, Ka-Ngo; Reijonen, Jani; Gicquel, Frederic; Hahto, Sami; Lou, Tak-Pui

    2004-01-18

    The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory has been engaging in the development of high yield compact neutron generators for the last ten years. Because neutrons in these generators are formed by using either D-D, T-T or D-T fusion reaction, one can produce either mono-energetic (2.4 MeV or 14 MeV) or white neutrons. All the neutron generators being developed by our group utilize 13.5 MHz RF induction discharge to produce a pure deuterium or a mixture of deuterium-tritium plasma. As a result, ion beams with high current density and almost pure atomic ions can be extracted from the plasma source. The ion beams are accelerated to {approx}100 keV and neutrons are produced when the beams impinge on a titanium target. Neutron generators with different configurations and sizes have been designed and tested at LBNL. Their applications include neutron activation analysis, oil-well logging, boron neutron capture therapy, brachytherapy, cargo and luggage screening. A novel small point neutron source has recently been developed for radiography application. The source size can be 2 mm or less, making it possible to examine objects with sharper images. The performance of these neutron generators will be described in this paper.

  8. Next Generation Drivetrain Development and Test Program

    SciTech Connect

    Keller, Jonathan; Erdman, Bill; Blodgett, Doug; Halse, Chris; Grider, Dave

    2015-11-03

    This presentation was given at the Wind Energy IQ conference in Bremen, Germany, November 30 through December 2, 2105. It focused on the next-generation drivetrain architecture and drivetrain technology development and testing (including gearbox and inverter software and medium-voltage inverter modules.

  9. Gene regulation networks generate diverse pigmentation patterns in plants.

    PubMed

    Albert, Nick W; Davies, Kevin M; Schwinn, Kathy E

    2014-01-01

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants.

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

    PubMed

    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

  11. Polychromatic Optical Vortex Generation from Patterned Cholesteric Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Kobashi, Junji; Yoshida, Hiroyuki; Ozaki, Masanori

    2016-06-01

    Generation of optical vortices is described in cholesteric liquid crystals with a singular point in the spatial distribution of a helix phase. The phenomenon uses the fact that a Bragg reflected light phase varies in proportion to the spatial phase of the helix, both at normal and oblique incidences. Our proposal enables high-efficiency, polychromatic generation of optical vortices without the need of a cumbersome fabrication process and fine-tuning.

  12. Polychromatic Optical Vortex Generation from Patterned Cholesteric Liquid Crystals.

    PubMed

    Kobashi, Junji; Yoshida, Hiroyuki; Ozaki, Masanori

    2016-06-24

    Generation of optical vortices is described in cholesteric liquid crystals with a singular point in the spatial distribution of a helix phase. The phenomenon uses the fact that a Bragg reflected light phase varies in proportion to the spatial phase of the helix, both at normal and oblique incidences. Our proposal enables high-efficiency, polychromatic generation of optical vortices without the need of a cumbersome fabrication process and fine-tuning. PMID:27391724

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

    NASA Astrophysics Data System (ADS)

    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

  14. Pattern-set generation algorithm for the one-dimensional multiple stock sizes cutting stock problem

    NASA Astrophysics Data System (ADS)

    Cui, Yaodong; Cui, Yi-Ping; Zhao, Zhigang

    2015-09-01

    A pattern-set generation algorithm (PSG) for the one-dimensional multiple stock sizes cutting stock problem (1DMSSCSP) is presented. The solution process contains two stages. In the first stage, the PSG solves the residual problems repeatedly to generate the patterns in the pattern set, where each residual problem is solved by the column-generation approach, and each pattern is generated by solving a single large object placement problem. In the second stage, the integer linear programming model of the 1DMSSCSP is solved using a commercial solver, where only the patterns in the pattern set are considered. The computational results of benchmark instances indicate that the PSG outperforms existing heuristic algorithms and rivals the exact algorithm in solution quality.

  15. Career Development and Emerging Managerial Career Patterns.

    ERIC Educational Resources Information Center

    Grzeda, Maurice

    1999-01-01

    Career-motivation theory provides a new framework for managerial careers in the context of contemporary career patterns. The framework includes the concepts of career resilience, career insight, and career identity. (SK)

  16. Development of W-Ta generator

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This research program was used to further develop the existing W-Ta generator and to evaluate alternative adsorbents, preferably inorganic materials, as supports for the generator. During the first half year, combinations of non-complexing eluents and a variety of adsorbents, both inorganic and organic, were evaluated. Some of these adsorbents were synthetic, such as chelate resins that could be specific for tungsten. In the second half of the year, the stress was mainly on the use of complexing eluents because of the high affinity of hydrous oxides for tantalum, on the synthesis of chelate resins and on the use novel techniques (electrolytic) to solve the tantalum-adsorption problem.

  17. Development of a NASA standard gas generator

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Karp, Harold; Schimmel, Morry L.

    1993-01-01

    The goals of the NASA Standard Gas Generator (NSGG) Program are to create a NASA standard gas generating cartridge, characterize its performance, and make it readily available to users. A cartridge within the same envelope as the NASA Standard Initiator (NSI) has the greatest potential use. This potential use is described in viewgraph form. Our approach for NSGG development and qualification was planned to be conducted in several phases. Test methods were developed to evaluate output performance for a variety of potential applications. A feasibility study using modified NSI's was accomplished. Preliminary and final development will be conducted with a delta qualification to evaluate the effects of manufacturing lots and environments. Feasibility study results, feasibility study conclusions, and future plans are presented.

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

    PubMed Central

    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

  19. Microstencils to generate defined, multi-species patterns of bacteria

    DOE PAGESBeta

    Doktycz, Mitchel J.; Retterer, Scott T.; Pelletier, Dale A.; Timm, Collin M.; Hansen, Ryan R.

    2015-11-12

    Microbial communities are complex heterogeneous systems that are influenced by physical and chemical interactions with their environment, host, and community members. Techniques that facilitate the quantitative evaluation of how microscale organization influences the morphogenesis of multispecies communities could provide valuable insights into the dynamic behavior and organization of natural communities, the design of synthetic environments for multispecies culture, and the engineering of artificial consortia. In this work, we demonstrate a method for patterning microbes into simple arrangements that allow the quantitative measurement of growth dynamics as a function of their proximity to one another. The method combines parylene-based liftoff techniquesmore » with microfluidic delivery to simultaneously pattern multiple bacterial species with high viability using low-cost, customizable methods. Furthermore, quantitative measurements of bacterial growth for two competing isolates demonstrate that spatial coordination can play a critical role in multispecies growth and structure.« less

  20. Microstencils to generate defined, multi-species patterns of bacteria

    SciTech Connect

    Doktycz, Mitchel J.; Retterer, Scott T.; Pelletier, Dale A.; Timm, Collin M.; Hansen, Ryan R.

    2015-11-12

    Microbial communities are complex heterogeneous systems that are influenced by physical and chemical interactions with their environment, host, and community members. Techniques that facilitate the quantitative evaluation of how microscale organization influences the morphogenesis of multispecies communities could provide valuable insights into the dynamic behavior and organization of natural communities, the design of synthetic environments for multispecies culture, and the engineering of artificial consortia. In this work, we demonstrate a method for patterning microbes into simple arrangements that allow the quantitative measurement of growth dynamics as a function of their proximity to one another. The method combines parylene-based liftoff techniques with microfluidic delivery to simultaneously pattern multiple bacterial species with high viability using low-cost, customizable methods. Furthermore, quantitative measurements of bacterial growth for two competing isolates demonstrate that spatial coordination can play a critical role in multispecies growth and structure.

  1. 32 nm imprint masks using variable shape beam pattern generators

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. GENERATING FRACTAL PATTERNS BY USING p-CIRCLE INVERSION

    NASA Astrophysics Data System (ADS)

    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.

  4. Interference pattern generation in evanescent electromagnetic waves for nanoscale lithography using waveguide diffraction gratings

    SciTech Connect

    Bezus, E A; Doskolovich, L L; Kazanskii, N L

    2011-08-31

    The generation of interference patterns of evanescent electromagnetic waves with an essentially subwavelength period using dielectric waveguide diffraction gratings is considered. Using simulations within the framework of the electromagnetic theory, the possibility of obtaining high-quality interference patterns due to enhancement of evanescent diffraction orders under resonance conditions is demonstrated. The contrast of the interference patterns in the case of TE polarisation of the incident wave is close to unity. The field intensity in the near-field interference maxima exceeds the intensity of the incident wave by 25-100 times. The possibility of generation of the interference patterns of evanescent waves corresponding to higher diffraction orders is shown. The use of higher orders reduces the requirements to the fabrication technology and allows generation of interference patterns with a high spatial frequency, using diffraction gratings with a low spatial frequency. Examples of generating interference patters with periods six times smaller than those of the used diffraction gratings are presented. (nanolithography)

  5. Summary of 1971 pattern recognition program development

    NASA Technical Reports Server (NTRS)

    Whitley, S. L.

    1972-01-01

    Eight areas related to pattern recognition analysis at the Earth Resources Laboratory are discussed: (1) background; (2) Earth Resources Laboratory goals; (3) software problems/limitations; (4) operational problems/limitations; (5) immediate future capabilities; (6) Earth Resources Laboratory data analysis system; (7) general program needs and recommendations; and (8) schedule and milestones.

  6. Circulation control lift generation experiment: Hardware development

    NASA Technical Reports Server (NTRS)

    Panontin, T. L.

    1985-01-01

    A circulation control airfoil and its accompanying hardware were developed to allow the investigation of lift generation that is independent of airfoil angle of attack and relative flow velocity. The test equipment, designed for use in a water tunnel, includes the blown airfoil, the support systems for both flow visualization and airfoil load measurement, and the fluid control system, which utilizes hydraulic technology. The primary design tasks, the selected solutions, and the unforseen problems involved in the development of these individual components of hardware are described.

  7. TermGenie – a web-application for pattern-based ontology class generation

    SciTech Connect

    Dietze, Heiko; Berardini, Tanya Z.; Foulger, Rebecca E.; Hill, David P.; Lomax, Jane; Osumi-Sutherland, David; Roncaglia, Paola; Mungall, Christopher J.

    2014-01-01

    Biological ontologies are continually growing and improving from requests for new classes (terms) by biocurators. These ontology requests can frequently create bottlenecks in the biocuration process, as ontology developers struggle to keep up, while manually processing these requests and create classes. TermGenie allows biocurators to generate new classes based on formally specified design patterns or templates. The system is web-based and can be accessed by any authorized curator through a web browser. Automated rules and reasoning engines are used to ensure validity, uniqueness and relationship to pre-existing classes. In the last 4 years the Gene Ontology TermGenie generated 4715 new classes, about 51.4% of all new classes created. The immediate generation of permanent identifiers proved not to be an issue with only 70 (1.4%) obsoleted classes. Lastly, TermGenie is a web-based class-generation system that complements traditional ontology development tools. All classes added through pre-defined templates are guaranteed to have OWL equivalence axioms that are used for automatic classification and in some cases inter-ontology linkage. At the same time, the system is simple and intuitive and can be used by most biocurators without extensive training.

  8. TermGenie – a web-application for pattern-based ontology class generation

    DOE PAGESBeta

    Dietze, Heiko; Berardini, Tanya Z.; Foulger, Rebecca E.; Hill, David P.; Lomax, Jane; Osumi-Sutherland, David; Roncaglia, Paola; Mungall, Christopher J.

    2014-01-01

    Biological ontologies are continually growing and improving from requests for new classes (terms) by biocurators. These ontology requests can frequently create bottlenecks in the biocuration process, as ontology developers struggle to keep up, while manually processing these requests and create classes. TermGenie allows biocurators to generate new classes based on formally specified design patterns or templates. The system is web-based and can be accessed by any authorized curator through a web browser. Automated rules and reasoning engines are used to ensure validity, uniqueness and relationship to pre-existing classes. In the last 4 years the Gene Ontology TermGenie generated 4715 newmore » classes, about 51.4% of all new classes created. The immediate generation of permanent identifiers proved not to be an issue with only 70 (1.4%) obsoleted classes. Lastly, TermGenie is a web-based class-generation system that complements traditional ontology development tools. All classes added through pre-defined templates are guaranteed to have OWL equivalence axioms that are used for automatic classification and in some cases inter-ontology linkage. At the same time, the system is simple and intuitive and can be used by most biocurators without extensive training.« less

  9. Topology-generating interfacial pattern formation during liquid metal dealloying

    PubMed Central

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-01-01

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Moreover, we deduce scaling laws governing microstructural length scales and dealloying kinetics. PMID:26582248

  10. Topology-generating interfacial pattern formation during liquid metal dealloying

    DOE PAGESBeta

    Geslin, Pierre -Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-19

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growthmore » of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.« less

  11. Topology-generating interfacial pattern formation during liquid metal dealloying

    SciTech Connect

    Geslin, Pierre -Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-19

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.

  12. Micropunching lithography for generating micro- and submicron-patterns on polymer substrates.

    PubMed

    Chakraborty, Anirban; Liu, Xinchuan; Luo, Cheng

    2012-07-02

    Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 1977(1). They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications(2,3). Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials(4). For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form(5,6). One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes. A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers(4), polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures(7). The fabricated microstructures of conducting polymers have been used as humidity(8), chemical(8), and glucose

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Dynamical patterning modules: a "pattern language" for development and evolution of multicellular form.

    PubMed

    Newman, Stuart A; Bhat, Ramray

    2009-01-01

    This article considers the role played by a core set of "dynamical patterning modules" (DPMs) in the origination, development and evolution of complex organisms. These consist of the products of a subset of the genes of what has come to be known as the "developmental-genetic toolkit" in association with physical processes they mobilize. The physical processes are those characteristic of chemically and mechanically excitable mesoscopic systems like cell aggregates: cohesion, viscoelasticity, diffusion, spatiotemporal heterogeneity based on activator-inhibitor interaction, and multistable and oscillatory dynamics. We focus on the emergence of the Metazoa, and show how toolkit gene products and pathways that pre-existed the metazoans acquired novel morphogenetic functions simply by virtue of the change in scale and context inherent to multicellularity. We propose that DPMs, acting singly and in combination with each other, constitute a "pattern language" capable of generating all metazoan body plans and organ forms. This concept implies that the multicellular organisms of the late Precambrian-early Cambrian were phenotypically plastic, fluently exploring morphospace in a fashion decoupled from both function-based selection and genotypic change. The relatively stable developmental trajectories and morphological phenotypes of modern organisms, then, are considered to be products of stabilizing selection. This perspective solves the apparent "molecular homology-analogy paradox," whereby widely divergent modern animal types utilize the same molecular toolkit during development, but it does so by inverting the neo-Darwinian principle that phenotypic disparity was generated over long periods of time in concert with, and in proportion to genotypic change. PMID:19378259

  15. Development of a 500-Watt portable generator

    NASA Astrophysics Data System (ADS)

    Knochenhauer, Robert John

    In many commercial and recreational environments where power is unavailable, there is a need for lightweight, efficient, reasonably priced and quiet power sources that can recharge batteries for various portable devices. The current benchmark device is the Honda EU1000i, a 1000-Watt (peak) generator that weighs only 29 pounds (dry) and has a respectable noise level of 59 dB (at 7 meters) under peak power loading. The intent of this thesis study is to focus on the thermal management of a novel generator design that develops peak power of 500-Watts, weighs in at less than 20 pounds (dry) and has a reasonably low noise level at peak power loading. Through the course of this assessment, two key lessons are learned: • Liquid cooling at this scale is possible, but not practical • Renewable power sources (wind turbines and/or solar panels) are viable alternatives when used in environments that offer suitable conditions.

  16. SNAP-8 electrical generating system development program

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The SNAP-8 program has developed the technology base for one class of multikilowatt dynamic space power systems. Electrical power is generated by a turbine-alternator in a mercury Rankine-cycle loop to which heat is transferred and removed by means of sodium-potassium eutectic alloy subsystems. Final system overall criteria include a five-year operating life, restartability, man rating, and deliverable power in the 90 kWe range. The basic technology was demonstrated by more than 400,000 hours of major component endurance testing and numerous startup and shutdown cycles. A test system, comprised of developed components, delivered up to 35 kWe for a period exceeding 12,000 hours. The SNAP-8 system baseline is considered to have achieved a level of technology suitable for final application development for long-term multikilowatt space missions.

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

    PubMed

    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. Dot patterns from second-harmonic and sum-frequency generation in polycrystalline ZnSe

    NASA Astrophysics Data System (ADS)

    Chinh, Tran Duc; Seibt, Wolfgang; Siegbahn, Kai

    2001-09-01

    During a comparative study of second-harmonic generation (SHG) and sum-frequency generation (SFG) in single-crystal and polycrystalline ZnSe, the polycrystalline material showed a dot pattern in the SHG as well as in the SFG output. No such pattern was found in the output from the single-crystal ZnSe sample. The second-harmonic and also the sum-frequency dot pattern, resembling a diffraction pattern, could be observed over a wide tuning range of the fundamental beam, between 1.1 and 1.6 μm, generated by a femtosecond optical parametric amplifier. The size of the observed pattern is dependent on wavelength and the dots show a characteristic polarization.

  19. Central pattern generation involved in oral and respiratory control for feeding in the term infant

    PubMed Central

    Barlow, Steven M.

    2009-01-01

    Purpose of review Drinking and eating are essential skills for survival and benefit from the coordination of several pattern generating networks and their musculoskeletal effectors to achieve safe swallows. Oral-pharyngo-esophageal motility develops during infancy and early childhood, and is influenced by various factors, including neuromuscular maturation, dietary and postural habits, arousal state, ongoing illnesses, congenital anomalies, and the effects of medical or surgical interventions. Gastroesophageal reflux is frequent in neonates and infants, and its role in neonatal morbidity including dysphagia, chronic lung disease, or apparent life-threatening events is not well understood. This review highlights recent studies aimed at understanding the development of oral feeding skills, and cross-system interactions among the brainstem, spinal, and cerebral networks involved in feeding. Recent Findings Functional linkages between suck-swallow and swallow-respiration manifest transitional forms during late gestation through the first year of life which can be delayed or modified by sensory experience and/or disease processes. Relevant central pattern generator (CPG) networks and their neuromuscular targets attain functional status at different rates, which ultimately influences cross-system CPG interactions. Entrainment of trigeminal primary afferents accelerates pattern genesis for the suck CPG and transition-to-oral feed in the RDS preterm infant. Summary The genesis of within-system CPG control for rate and amplitude scaling matures differentially for suck, mastication, swallow, and respiration. Cross-system interactions among these CPGs represent targets of opportunity for new interventions which optimize experience-dependent mechanisms to promote safe swallows among newborn and pediatric patients. PMID:19417662

  20. A Novel Wideband Subarray Technique for Shaped Pattern Generation and Adaptively Interference Rejection

    NASA Astrophysics Data System (ADS)

    Alfred, Q. Md.; Chakravarty, T.; Singh, G.; Sanyal, S. K.

    2008-03-01

    In this article, a simple and efficient technique for the wideband shaped beam and sector beam pattern generation with their adaptive interference rejection is proposed. A microcontroller controlled and time delay based beam forming network for simultaneously generating multiple beams, shaped beam and sector beam is conceptualized. The antenna patterns considered here is formed by linear array of isotropic elements grouped as subarray. The shaped and sector beam synthesis procedure is practically simplified by simultaneous adding the constituents beams from the subarrays, was theoretically established by Woodward and Lawson (Proc. IEE. 95(1):362 370, 1948). Apart from the shaped beam generation a technique for adaptive interference rejection in shaped patterns using combination of time delay and phase shifter is discussed. This topic promises good prospect for wideband pattern generation and interference rejection.

  1. A new Pulse-Pattern Generator based on LabVIEW FPGA

    NASA Astrophysics Data System (ADS)

    Ziegler, F.; Beck, D.; Brand, H.; Hahn, H.; Marx, G.; Schweikhard, L.

    2012-07-01

    For the control of experimental sequences composed of triggers, gates and delays a Pulse-Pattern Generator (PPG) has been developed based on a Field Programmable Gate Array (FPGA) addressed in a LabVIEW environment. It allows a highly reproducible timing of measurement procedures by up to 64 individual channels with pulse and delay periods from the nanoseconds to the minutes range. The PPG has been implemented in the context of the development of a new control system for the ClusterTrap setup, an ion storage device for atomic-cluster research, in close contact with the SHIPTRAP and ISOLTRAP collaborations at GSI and CERN, respectively. As the new PPG is not ion-trap specific it can be employed in any experiment based on sequences of triggers, pulses and delays.

  2. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    PubMed Central

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-01-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment. PMID:26902520

  3. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    NASA Astrophysics Data System (ADS)

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-02-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment.

  4. Making a Swim Central Pattern Generator Out of Latent Parabolic Bursters

    NASA Astrophysics Data System (ADS)

    Alaçam, Deniz; Shilnikov, Andrey

    2015-06-01

    We study the rhythmogenesis of oscillatory patterns emerging in network motifs composed of inhibitory coupled tonic spiking neurons represented by the Plant model of R15 nerve cells. Such motifs are argued to be used as building blocks for a larger central pattern generator network controlling swim locomotion of sea slug Melibe leonina.

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

    ERIC Educational Resources Information Center

    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…

  6. Development of a portable thermophotovoltaic power generator

    NASA Astrophysics Data System (ADS)

    Becker, Frederick E.; Doyle, Edward F.; Shukla, Kailash

    1997-03-01

    A 150 Watt thermophotovoltaic (TPV) power generator is being developed. The technical approach taken in the design focused on optimizing the integrated performance of the primary subsystems in order to yield high energy conversion efficiency and cost effectiveness. An important aspect of the approach is the use of a selective emitter radiating to a bandgap matched photovoltaic array to minimize thermal and optical recuperation requirements, as well as the non-recoverable heat losses. For the initial prototype system, fibrous ytterbia emitters radiating in a band centered at 980 nm are matched with high efficiency silicon photoconverters. The integrated system includes a dielectric stack filter for optical energy recovery and a ceramic recuperator for thermal energy recovery. The system has been operated with air preheat temperatures up to 1350K. The design of the system and development status are presented.

  7. An Experimental and Theoretical Study of Fracture Patterns Generated by Underground Explosions

    NASA Astrophysics Data System (ADS)

    Bhat, H.; Mihaly, J. M.; Rosakis, A.; Sammis, C. G.

    2012-12-01

    A dynamic micro-mechanical damage mechanics model, developed by Bhat, Rosakis and Sammis, J. Appl. Mech., 2012, is used to simulate two-dimensional explosions in a brittle material. The theoretical patterns of circumferential and radial fractures are quantitatively compared with those produced by point explosions in very brittle "candy glass" plates. In these experiments the evolution of the fracture pattern is monitored using high-speed digital photography, which also images the resultant elastic waves (P and S). Theoretical estimates of the spatial extent of circumferential and radial cracking as well as the propagation speed of the comminution front and the growth-rate of individual radial cracks all compare well with the experimental observations. The wave-forms of the P and S waves, specifically the local particle velocities, are also recorded at selected points using laser vibrometers. Asymmetric fracture patterns caused by a non isotropic pre-stress, the preferred orientation of initial flaws (a rift plane), or a lithostatic gradient lead to the generation of strong S-waves from the otherwise spherically symmetric point source.

  8. Developing the Second Generation CMORPH: A Prototype

    NASA Astrophysics Data System (ADS)

    Xie, Pingping; Joyce, Robert

    2014-05-01

    A prototype system of the second generation CMORPH is being developed at NOAA Climate Prediction Center (CPC) to produce global analyses of 30-min precipitation on a 0.05deg lat/lon grid over the entire globe from pole to pole through integration of information from satellite observations as well as numerical model simulations. The second generation CMORPH is built upon the Kalman Filter based CMORPH algorithm of Joyce and Xie (2011). Inputs to the system include rainfall and snowfall rate retrievals from passive microwave (PMW) measurements aboard all available low earth orbit (LEO) satellites, estimates derived from infrared (IR) observations of geostationary (GEO) as well as LEO platforms, and precipitation simulations from numerical global models. First, precipitation estimation / retrievals from various sources are mapped onto a global grid of 0.05deg lat/lon and calibrated against a common reference field to ensure consistency in their precipitation rate PDF structures. The motion vectors for the precipitating cloud systems are then defined using information from both satellite IR observations and precipitation fields generated by the NCEP Climate Forecast System Reanalysis (CFSR). To this end, motion vectors are first computed from CFSR hourly precipitation fields through cross-correlation analysis of consecutive hourly precipitation fields on the global T382 (~35 km) grid. In a similar manner, separate processing is also performed on satellite IR-based precipitation estimates to derive motion vectors from observations. A blended analysis of precipitating cloud motion vectors is then constructed through the combination of CFSR and satellite-derived vectors with an objective analysis technique. Fine resolution mapped PMW precipitation retrievals are then separately propagated along the motion vectors from their respective observation times to the target analysis time from both forward and backward directions. The CMORPH high resolution precipitation analyses

  9. Alcohol Consumption Patterns in Immigrant and Later Generation Mexican American Women.

    ERIC Educational Resources Information Center

    Gilbert, M. Jean

    1987-01-01

    Immigrant Mexican women's drinking patterns were compared with those of Mexican women in Mexico, other United States Latinas, later-generation Mexican-American women, and male immigrants. Changes in the direction of greater permissiveness and rationalization of alcohol use among later-generation Mexican-American women are demonstrated. (JMM)

  10. Effects of Differences in Working Memory Capacity on Patterns of Word Generation

    ERIC Educational Resources Information Center

    Kawamura, Mimpei; Kobayashi, Yasutaka; Morioka, Shu

    2012-01-01

    In recent years, it has been reported that WM (working memory) is concerned with word generation, but many points regarding the relationship between the individual differences of WM capacity and the patterns of word generation remain unclear. This study is to investigate these unclear points by using three types of word fluency task with different…

  11. Mechanisms of left-right coordination in mammalian locomotor pattern generation circuits: a mathematical modeling view.

    PubMed

    Molkov, Yaroslav I; Bacak, Bartholomew J; Talpalar, Adolfo E; Rybak, Ilya A

    2015-05-01

    The locomotor gait in limbed animals is defined by the left-right leg coordination and locomotor speed. Coordination between left and right neural activities in the spinal cord controlling left and right legs is provided by commissural interneurons (CINs). Several CIN types have been genetically identified, including the excitatory V3 and excitatory and inhibitory V0 types. Recent studies demonstrated that genetic elimination of all V0 CINs caused switching from a normal left-right alternating activity to a left-right synchronized "hopping" pattern. Furthermore, ablation of only the inhibitory V0 CINs (V0D subtype) resulted in a lack of left-right alternation at low locomotor frequencies and retaining this alternation at high frequencies, whereas selective ablation of the excitatory V0 neurons (V0V subtype) maintained the left-right alternation at low frequencies and switched to a hopping pattern at high frequencies. To analyze these findings, we developed a simplified mathematical model of neural circuits consisting of four pacemaker neurons representing left and right, flexor and extensor rhythm-generating centers interacting via commissural pathways representing V3, V0D, and V0V CINs. The locomotor frequency was controlled by a parameter defining the excitation of neurons and commissural pathways mimicking the effects of N-methyl-D-aspartate on locomotor frequency in isolated rodent spinal cord preparations. The model demonstrated a typical left-right alternating pattern under control conditions, switching to a hopping activity at any frequency after removing both V0 connections, a synchronized pattern at low frequencies with alternation at high frequencies after removing only V0D connections, and an alternating pattern at low frequencies with hopping at high frequencies after removing only V0V connections. We used bifurcation theory and fast-slow decomposition methods to analyze network behavior in the above regimes and transitions between them. The model

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Automatic Generation of English-Japanese Translation Pattern Utilizing Genetic Programming Technique

    NASA Astrophysics Data System (ADS)

    Matsumura, Koki; Tamekuni, Yuji; Kimura, Shuhei

    There are a lot of constructional differences in an English-Japanese phrase template, and that often makes the act of translation difficult. Moreover, there exist various and tremendous phrase templates and sentence to be refered to. It is not easy to prepare the corpus that covers the all. Therefore, it is very significant to generate the translation pattern of the sentence pattern automatically from a viewpoint of the translation success rate and the capacity of the pattern dictionary. Then, for the purpose of realizing the automatic generation of the translation pattern, this paper proposed the new method for the generation of the translation pattern by using the genetic programming technique (GP). The technique tries to generate the translation pattern of various sentences which are not registered in the phrase template dictionary automatically by giving the genetic operation to the parsing tree of a basic pattern. The tree consists of the pair of the English-Japanese sentence generated as the first stage population. The analysis tree data base with 50,100,150,200 pairs was prepared as the first stage population. And this system was applied and executed for an English input of 1,555 sentences. As a result, the analysis tree increases from 200 to 517, and the accuracy rate of the translation pattern has improved from 42.57% to 70.10%. And, 86.71% of the generated translations was successfully done, whose meanings are enough acceptable and understandable. It seemed that this proposal technique became a clue to raise the translation success rate, and to find the possibility of the reduction of the analysis tree data base.

  14. Pakistan's pattern of development and prospects.

    PubMed

    Baqui, M

    1979-01-01

    This paper analyzes past and present development experiences in Pakistan, and gives indications of possible directions for future development. Since 1969 there has been an open dissatisfaction with economic management from the government, which has resulted in a drying up of private investment. However, this drawback was partly balanced by a rapid increase in income received by Pakistanis working abroad, particularly in the Middle East. There have been slight increases in growth in agriculture, industry, and in the service sector, such as banking, insurance, and shipping. The growth of per capita income, however, is constantly offset by the acceleration in population growth, which has reached 3% a year. Literacy rate is still 19% of the total population, and basic health facilities cover only 50% of the population, while potable water supply is available to 11.2% of the rural population. Possible development directions would include the denationalization of some industries, and the creation of competition between the private and public sectors, so to improve the climate for private investment. Water availability for land irrigation should be expanded, and mineral fields better surveyed and exploited. Pakistan should develop the possibility of growing trade offered by its geographical location, improve all kinds of social services, including family planning, education, and health services, and provide the means to produce energy for all the prospected programs. PMID:12261814

  15. Pakistan's pattern of development and prospects.

    PubMed

    Baqui, M

    1979-01-01

    This paper analyzes past and present development experiences in Pakistan, and gives indications of possible directions for future development. Since 1969 there has been an open dissatisfaction with economic management from the government, which has resulted in a drying up of private investment. However, this drawback was partly balanced by a rapid increase in income received by Pakistanis working abroad, particularly in the Middle East. There have been slight increases in growth in agriculture, industry, and in the service sector, such as banking, insurance, and shipping. The growth of per capita income, however, is constantly offset by the acceleration in population growth, which has reached 3% a year. Literacy rate is still 19% of the total population, and basic health facilities cover only 50% of the population, while potable water supply is available to 11.2% of the rural population. Possible development directions would include the denationalization of some industries, and the creation of competition between the private and public sectors, so to improve the climate for private investment. Water availability for land irrigation should be expanded, and mineral fields better surveyed and exploited. Pakistan should develop the possibility of growing trade offered by its geographical location, improve all kinds of social services, including family planning, education, and health services, and provide the means to produce energy for all the prospected programs.

  16. Patterns of Stepchild-Stepparent Relationship Development

    ERIC Educational Resources Information Center

    Ganong, Lawrence H.; Coleman, Marilyn; Jamison, Tyler

    2011-01-01

    Thirty-two stepdaughters and 17 stepsons participated in this grounded theory study of emerging adult stepchildren's perceptions about how relationships with their stepparents developed. The theory created from this study proposes that the degree to which stepchildren engage in relationship-building and -maintaining behaviors with stepparents is a…

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

    NASA Astrophysics Data System (ADS)

    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.

  18. [Study on the control of dynamic artificial limb ankle based on central pattern generator].

    PubMed

    Guo, Xin; Xu, Caiyu; Li, Mingyue; Su, Longtao

    2014-12-01

    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 learn- ing 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 im- portant practical value for intelligent prosthesis development based on this analysis of technology.

  19. Field ion source development for neutron generators

    NASA Astrophysics Data System (ADS)

    Bargsten Johnson, B.; Schwoebel, P. R.; Holland, C. E.; Resnick, P. J.; Hertz, K. L.; Chichester, D. L.

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption (˜20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with ˜10,000 tip arrays have achieved deuterium ion currents of ˜50 nA. Neutron production by field ionization has yielded ˜10 2 n/s from ˜1 mm 2 of array area using the deuterium-deuterium fusion reaction at 90 kV.

  20. Field Ion Source Development for Neutron Generators

    SciTech Connect

    B. Bargsten Johnson; P. R. Schwoebel; C. E. Holland; P. J. Resnick; K. L. Hertz; D. L. Chichester

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption ({approx}20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with {approx}10,000 tip arrays have achieved deuterium ion currents of {approx}50 nA. Neutron production by field ionization has yielded {approx}10{sup 2} n/s from {approx}1 mm{sup 2} of array area using the deuterium-deuterium fusion reaction at 90 kV.

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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    Bullara, D.; de Decker, Y.

    2015-05-01

    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.

  3. Revisit Pattern Blocks to Develop Rational Number Sense

    ERIC Educational Resources Information Center

    Champion, Joe; Wheeler, Ann

    2014-01-01

    Pattern blocks are inexpensive wooden, foam, or plastic manipulatives developed in the 1960s to help students build an understanding of shapes, proportions, equivalence, and fractions (EDC 1968). The colorful collection of basic shapes in classic pattern block kits affords opportunities for amazing puzzle-like problem-solving tasks and for…

  4. Research Issues in Evaluating Learning Pattern Development in Higher Education

    ERIC Educational Resources Information Center

    Richardson, John T. E.

    2013-01-01

    This article concludes the special issue of "Studies in Educational Evaluation" concerned with "Evaluating learning pattern development in higher education" by discussing research issues that have emerged from the previous contributions. The article considers in turn: stability versus variability in learning patterns; old versus new analytic…

  5. PATTERNS OF GENICULAR DEVELOPMENT IN AMPHIROA (CORALLINACEAE).

    PubMed

    Johansen, H W

    1969-06-01

    Two types of genicular development (designated Types I and II) are present in South African species of Amphiroa. Genicula of both types originate when medullary tissue near branch endings softens by decalcification. In Type I decalcification does not progress to the branch surface and the joint therefore does not become flexible until the cortex, which remains calcified, cracks and partly sloughs. This type occurs in all species of Amphiroa in South Africa except one, and possibly occurs in those in the rest of the world as well. In Type II decalcification continues centrifugally to the surface of the branch; this results in a geniculum comprising medullary and cortical tissue. As far as is known this type occurs only in Amphiroa ephedraea. Type I appears to be more primitive than Type II.

  6. Next generation limb development and evolution: old questions, new perspectives.

    PubMed

    Zuniga, Aimée

    2015-11-15

    The molecular analysis of limb bud development in vertebrates continues to fuel our understanding of the gene regulatory networks that orchestrate the patterning, proliferation and differentiation of embryonic progenitor cells. In recent years, systems biology approaches have moved our understanding of the molecular control of limb organogenesis to the next level by incorporating next generation 'omics' approaches, analyses of chromatin architecture, enhancer-promoter interactions and gene network simulations based on quantitative datasets into experimental analyses. This Review focuses on the insights these studies have given into the gene regulatory networks that govern limb development and into the fin-to-limb transition and digit reductions that occurred during the evolutionary diversification of tetrapod limbs. PMID:26577204

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

    PubMed

    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

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

    PubMed Central

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

    2016-01-01

    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

  9. Development of Pattern Recognition in Infant Pigtailed Macaques (Macaca nemestrina).

    ERIC Educational Resources Information Center

    Gunderson, Virginia M.; Sackett, Gene P.

    1984-01-01

    Examined the development of pattern recognition in infant pigtailed macaques using the familiarization novelty technique. Results indicate that by at least 200 days postconception subjects show a consistently reliable visual response to novelty. (Author/RH)

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

    PubMed Central

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

    2016-01-01

    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. PMID:27230944

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Development of tungsten-tantalum generator

    NASA Astrophysics Data System (ADS)

    Leblanc, A.; Babich, J.; Jhingran, S. G.

    The purpose of this project was to develop a useable tungsten (W)/tantalum (Ta) generator. Ta-178 is formed following the decay of its parent, W-178 (half-life: 21.7d) and has a half life of 9.3 minutes in turn yielding stable Hf-178. The decay of the parent isotope (W-178) occurs entirely by electron capture to the 9.3 minute Ta-178 state, without feeding the high spin Ta-178 isomer (half life 2.2 hours). In Ta-178 decay, 99.2% of the disintegrations proceed by electron capture and 0.18% by positron emission. Electron capture results in a 61.2% branch to the ground state of Hf-178 and 33.7% to the first excited state at 93 1KeV. The most prominent features of the radionuclide's energy spectrum are the hafnium characteristic radiation peaks with energies between 54.6 and 65.0 KeV. The radiation exposure dose of Ta-118 was calculated to be approximately one-twentieth that of Tc-99m on a per millicurie basis. A twenty-fold reduction in radiation exposure from Ta-178 compared with Tc-99m means that the usual administered dose can be increased three or four times, greatly increasing statistical accuracy while reducing radiation exposure by a factor of five.

  13. Developing instrumentation to characterize thermoelectric generator modules.

    PubMed

    Liu, Dawei; Li, Qiming; Peng, Wenbo; Zhu, Lianjun; Gao, Hu; Meng, Qingsen; Jin, A J

    2015-03-01

    Based on the law of physics, known as "Seebeck effect," a thermoelectric generator (TEG) produces electricity when the temperature differential is applied across the TEG. This article reports a precision method in characterizing TEG modules. A precision instrument is constructed to study thermoelectric conversion in terms of output power and efficiency of TEG modules. The maximum allowable TEG module size is 150 mm, and the preferred size is from 30 mm to 60 mm. During measurements, the highest hot side temperature is 500 °C and the cold side temperature can be adjusted from room temperature to 100 °C. A mechanical structure is developed to control the pressure and parallelism of the clamping force of the TEG on both its hot and cold sides. A heat flux measurement module is installed at its cold side, and the heat flux through TEGs can be measured in position. Finally, the energy conversion efficiency of TEGs is calculated from experimental data of both an output power and a heat flux. PMID:25832254

  14. Developing instrumentation to characterize thermoelectric generator modules

    NASA Astrophysics Data System (ADS)

    Liu, Dawei; Li, Qiming; Peng, Wenbo; Zhu, Lianjun; Gao, Hu; Meng, Qingsen; Jin, A. J.

    2015-03-01

    Based on the law of physics, known as "Seebeck effect," a thermoelectric generator (TEG) produces electricity when the temperature differential is applied across the TEG. This article reports a precision method in characterizing TEG modules. A precision instrument is constructed to study thermoelectric conversion in terms of output power and efficiency of TEG modules. The maximum allowable TEG module size is 150 mm, and the preferred size is from 30 mm to 60 mm. During measurements, the highest hot side temperature is 500 °C and the cold side temperature can be adjusted from room temperature to 100 °C. A mechanical structure is developed to control the pressure and parallelism of the clamping force of the TEG on both its hot and cold sides. A heat flux measurement module is installed at its cold side, and the heat flux through TEGs can be measured in position. Finally, the energy conversion efficiency of TEGs is calculated from experimental data of both an output power and a heat flux.

  15. Development of tungsten-tantalum generator

    NASA Technical Reports Server (NTRS)

    Leblanc, A.; Babich, J.; Jhingran, S. G.

    1985-01-01

    The purpose of this project was to develop a useable tungsten (W)/tantalum (Ta) generator. Ta-178 is formed following the decay of its parent, W-178 (half-life: 21.7d) and has a half life of 9.3 minutes in turn yielding stable Hf-178. The decay of the parent isotope (W-178) occurs entirely by electron capture to the 9.3 minute Ta-178 state, without feeding the high spin Ta-178 isomer (half life 2.2 hours). In Ta-178 decay, 99.2% of the disintegrations proceed by electron capture and 0.18% by positron emission. Electron capture results in a 61.2% branch to the ground state of Hf-178 and 33.7% to the first excited state at 93 1KeV. The most prominent features of the radionuclide's energy spectrum are the hafnium characteristic radiation peaks with energies between 54.6 and 65.0 KeV. The radiation exposure dose of Ta-118 was calculated to be approximately one-twentieth that of Tc-99m on a per millicurie basis. A twenty-fold reduction in radiation exposure from Ta-178 compared with Tc-99m means that the usual administered dose can be increased three or four times, greatly increasing statistical accuracy while reducing radiation exposure by a factor of five.

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

    PubMed

    Hückesfeld, Sebastian; Schoofs, Andreas; Schlegel, Philipp; Miroschnikow, Anton; Pankratz, Michael J

    2015-01-01

    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. PMID:26252658

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

    PubMed Central

    Hückesfeld, Sebastian; Schoofs, Andreas; Schlegel, Philipp; Miroschnikow, Anton; Pankratz, Michael J.

    2015-01-01

    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. PMID:26252658

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed

    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.

  1. The "Chaos" Pattern in Piaget's Theory of Cognitive Development.

    ERIC Educational Resources Information Center

    Lindsay, Jean S.

    Piaget's theory of the cognitive development of the child is related to the recently developed non-linear "chaos" model. The term "chaos" refers to the tendency of dynamical, non-linear systems toward irregular, sometimes unpredictable, deterministic behavior. Piaget identified this same pattern in his model of cognitive development in children.…

  2. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect

    Cem Sarica; Holden Zhang

    2006-05-31

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The

  3. Oscillatory Pattern Generation of the Olfactory Center Using Pulse-Type Hardware Chaotic Neuron Models

    NASA Astrophysics Data System (ADS)

    Saito, Ken; Hatano, Hirokazu; Saito, Minoru; Sekine, Yoshifumi

    Oscillatory patterns of electrical activity are a ubiquitous feature in nervous systems. Oscillatory patterns play an important role in the processing of sensory information pattern recognition. For example, earlier reports describe that the oscillatory patterns in the olfactory center of the land slug are changed by odor stimuli to the tentacles. Olfactory processing has also been studied in relation to rabbits and land slugs through the construction and use of mathematical neural network models. However, a large-scale model is necessary for the study of a model which has sensory information recognition by the oscillatory pattern. Therefore, the construction of a hardware model that can generate oscillatory patterns is desired because nonlinear operations can be processed at higher speeds than the mathematical model. We are studying about the neural network using hardware neuron models to construct the olfactory center model of the living organisms. In the present study, we discuss about the oscillatory pattern generation of the olfactory center using pulse-type hardware chaotic neuron models. Our model shows periodic, quasi-periodic and chaotic oscillations such as the olfactory center of living organisms by changing the synaptic connection weights.

  4. Automating the generation of lexical patterns for processing free text in clinical documents

    PubMed Central

    Morioka, Craig

    2015-01-01

    Objective Many tasks in natural language processing utilize lexical pattern-matching techniques, including information extraction (IE), negation identification, and syntactic parsing. However, it is generally difficult to derive patterns that achieve acceptable levels of recall while also remaining highly precise. Materials and Methods We present a multiple sequence alignment (MSA)-based technique that automatically generates patterns, thereby leveraging language usage to determine the context of words that influence a given target. MSAs capture the commonalities among word sequences and are able to reveal areas of linguistic stability and variation. In this way, MSAs provide a systemic approach to generating lexical patterns that are generalizable, which will both increase recall levels and maintain high levels of precision. Results The MSA-generated patterns exhibited consistent F1-, F.5-, and F2- scores compared to two baseline techniques for IE across four different tasks. Both baseline techniques performed well for some tasks and less well for others, but MSA was found to consistently perform at a high level for all four tasks. Discussion The performance of MSA on the four extraction tasks indicates the method’s versatility. The results show that the MSA-based patterns are able to handle the extraction of individual data elements as well as relations between two concepts without the need for large amounts of manual intervention. Conclusion We presented an MSA-based framework for generating lexical patterns that showed consistently high levels of both performance and recall over four different extraction tasks when compared to baseline methods. PMID:25977405

  5. EIDA Next Generation: ongoing and future developments

    NASA Astrophysics Data System (ADS)

    Strollo, Angelo; Quinteros, Javier; Sleeman, Reinoud; Trani, Luca; Clinton, John; Stammler, Klaus; Danecek, Peter; Pedersen, Helle; Ionescu, Constantin

    2015-04-01

    The European Integrated Data Archive (EIDA; http://www.orfeus-eu.org/eida/eida.html) is the distributed Data Centre system within ORFEUS, providing transparent access and services to high quality, seismic data across (currently) 9 large data archives in Europe. EIDA is growing, in terms of the number of participating data centres, the size of the archives, the variability of the data in the archives, the number of users, and the volume of downloads. The on-going success of EIDA is thus providing challenges that are the driving force behind the design of the next generation (NG) of EIDA, which is expected to be implemented within EPOS IP. EIDA ORFEUS must cope with further expansion of the system and more complex user requirements by developing new techniques and extended services. The EIDA NG is being designed to work on standard FDSN web services and two additional new web services: Routing Service and QC (quality controlled) service. This presentation highlights the challenges EIDA needs to address during the EPOS IP and focuses on these 2 new services. The Routing Service can be considered as the core of EIDA NG. It was designed to assist users and clients to locate data within a federated, decentralized data centre (e.g. EIDA). A detailed, FDSN-compliant specification of the service has been developed. Our implementation of this service will run at every EIDA node, but is also capable of running on a user's computer, allowing anyone to define virtual or integrate existing data centres. This (meta)service needs to be queried in order to locate the data. Some smart clients (in a beta status) have been also provided to offer the user an integrated view of the whole EIDA, hiding the complexity of its internal structure. The service is open and able to be queried by anyone without the need of credentials or authentication. The QC Service is developed to cope with user requirements to query for relevant data only. The web service provides detailed information on the

  6. 2nd Generation ELT Performance Specification Development

    NASA Technical Reports Server (NTRS)

    Stimson, Chad M.

    2015-01-01

    NASA Search And Rescue is supporting RTCA SC-229 with research and recommendations for performance specifications for the 2nd generation of emergency locator transmitters. Areas for improvement and methods for collecting data will be presented.

  7. Spontaneous neuronal burst discharges as dependent and independent variables in the maturation of cerebral cortex tissue cultured in vitro: a review of activity-dependent studies in live 'model' systems for the development of intrinsically generated bioelectric slow-wave sleep patterns.

    PubMed

    Corner, Michael A

    2008-11-01

    A survey is presented of recent experiments which utilize spontaneous neuronal spike trains as dependent and/or independent variables in developing cerebral cortex cultures when synaptic transmission is interfered with for varying periods of time. Special attention is given to current difficulties in selecting suitable preparations for carrying out biologically relevant developmental studies, and in applying spike-train analysis methods with sufficient resolution to detect activity-dependent age and treatment effects. A hierarchy of synchronized nested burst discharges which approximate early slow-wave sleep patterns in the intact organism is established as a stable basis for isolated cortex function. The complexity of reported long- and short-term homeostatic responses to experimental interference with synaptic transmission is reviewed, and the crucial role played by intrinsically generated bioelectric activity in the maturation of cortical networks is emphasized.

  8. Turing patterns in development: what about the horse part?

    PubMed

    Marcon, Luciano; Sharpe, James

    2012-12-01

    For many years Turing patterns-the repetitive patterns which Alan Turing proved could arise from simple diffusing and interacting factors-have remained an interesting theoretical possibility, rather than a central concern of the developmental biology community. Recently however, this has started to change, with an increasing number of studies combining both experimental and theoretical work to reveal how Turing models may underlie a variety of patterning or morphogenetic processes. We review here the recent developments in this field across a wide range of model systems.

  9. Turing patterns in development: what about the horse part?

    PubMed

    Marcon, Luciano; Sharpe, James

    2012-12-01

    For many years Turing patterns-the repetitive patterns which Alan Turing proved could arise from simple diffusing and interacting factors-have remained an interesting theoretical possibility, rather than a central concern of the developmental biology community. Recently however, this has started to change, with an increasing number of studies combining both experimental and theoretical work to reveal how Turing models may underlie a variety of patterning or morphogenetic processes. We review here the recent developments in this field across a wide range of model systems. PMID:23276682

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

    PubMed

    Krylov, Victor V

    2016-07-01

    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 representation. It is demonstrated that the simple approach using a dipole-source representation of laser-generated sound is rather limited, especially for description of generated longitudinal acoustic waves. A practical criterion is established to define the conditions under which the dipole-source representation gives predictions with acceptable errors. It is shown that, for radiation in the normal direction to the surface, the amplitudes of longitudinal waves are especially sensitive to the values of thermal parameters and of the acoustic reflection coefficient from a free solid surface. A discussion is given on the possibility of using such a high sensitivity to the values of the reflection coefficient for investigation of surface properties of real solids.

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

    PubMed

    Krylov, Victor V

    2016-07-01

    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 representation. It is demonstrated that the simple approach using a dipole-source representation of laser-generated sound is rather limited, especially for description of generated longitudinal acoustic waves. A practical criterion is established to define the conditions under which the dipole-source representation gives predictions with acceptable errors. It is shown that, for radiation in the normal direction to the surface, the amplitudes of longitudinal waves are especially sensitive to the values of thermal parameters and of the acoustic reflection coefficient from a free solid surface. A discussion is given on the possibility of using such a high sensitivity to the values of the reflection coefficient for investigation of surface properties of real solids. PMID:26851995

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

    ERIC Educational Resources Information Center

    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…

  13. Dynamic mechanisms of generation of oscillatory cluster patterns in a globally coupled chemical system

    NASA Astrophysics Data System (ADS)

    Rotstein, Horacio G.; Wu, Hui

    2012-09-01

    We use simulations and dynamical systems tools to investigate the mechanisms of generation of phase-locked and localized oscillatory cluster patterns in a globally coupled Oregonator model where the activator receives global feedback from the inhibitor, mimicking experimental results observed in the photosensitive Belousov-Zhabotinsky reaction. A homogeneous two-cluster system (two clusters with equal cluster size) displays antiphase patterns. Heterogenous two-cluster systems (two clusters with different sizes) display both phase-locked and localized patterns depending on the parameter values. In a localized pattern the oscillation amplitude of the largest cluster is roughly an order of magnitude smaller than the oscillation amplitude of the smaller cluster, reflecting the effect of self-inhibition exerted by the global feedback term. The transition from phase-locked to localized cluster patterns occurs as the intensity of global feedback increases. Three qualitatively different basic mechanisms, described previously for a globally coupled FitzHugh-Nagumo model, are involved in the generation of the observed patterns. The swing-and-release mechanism is related to the canard phenomenon (canard explosion of limit cycles) in relaxation oscillators. The hold-and-release and hold-and-escape mechanisms are related to the release and escape mechanisms in synaptically connected neural models. The methods we use can be extended to the investigation of oscillatory chemical reactions with other types of non-local coupling.

  14. Dynamic mechanisms of generation of oscillatory cluster patterns in a globally coupled chemical system.

    PubMed

    Rotstein, Horacio G; Wu, Hui

    2012-09-14

    We use simulations and dynamical systems tools to investigate the mechanisms of generation of phase-locked and localized oscillatory cluster patterns in a globally coupled Oregonator model where the activator receives global feedback from the inhibitor, mimicking experimental results observed in the photosensitive Belousov-Zhabotinsky reaction. A homogeneous two-cluster system (two clusters with equal cluster size) displays antiphase patterns. Heterogenous two-cluster systems (two clusters with different sizes) display both phase-locked and localized patterns depending on the parameter values. In a localized pattern the oscillation amplitude of the largest cluster is roughly an order of magnitude smaller than the oscillation amplitude of the smaller cluster, reflecting the effect of self-inhibition exerted by the global feedback term. The transition from phase-locked to localized cluster patterns occurs as the intensity of global feedback increases. Three qualitatively different basic mechanisms, described previously for a globally coupled FitzHugh-Nagumo model, are involved in the generation of the observed patterns. The swing-and-release mechanism is related to the canard phenomenon (canard explosion of limit cycles) in relaxation oscillators. The hold-and-release and hold-and-escape mechanisms are related to the release and escape mechanisms in synaptically connected neural models. The methods we use can be extended to the investigation of oscillatory chemical reactions with other types of non-local coupling. PMID:22979891

  15. Dependence of gait pattern on the type of coupling between hind- and forelimb generators: modelling study.

    PubMed

    Zmysłowski, W; Kasicki, S

    1982-01-01

    Dependence of gait pattern on the way of possible coupling between fore and hindlimb girdles was investigated. This dependence was analysed using the analog model of neuronal net of spinal generator. Both nets (i.e., for fore and hind girdles) could be synchronized by any coupling between the executive and intrinsic elements. However, only few of them assured generation of patterns corresponding to physiological gaits. Patterns corresponding to walk and trot were obtained with inhibitory connections from hind intrinsic elements to fore executive ones. Pace was obtained at the coupling connections directed from hind executive elements to fore ones. To obtain gallop it was necessary to couple fore executive elements with hind ones by inhibitory connections.

  16. Generation of mask patterns for diffractive optical elements using Mathematica{sup T}{sup M}

    SciTech Connect

    OShea, D.C.

    1996-07-01

    The generation of binary and grayscale masks used in the fabrication of diffractive optical elements is usually performed using a proprietary piece of software or a computer-aided drafting package. Once the pattern is computed or designed, it must be output to a plotting or imaging system that will produce a reticle plate. This article describes a number of short Mathematica modules that can be used to generate binary and grayscale patterns in a PostScript-compatible format. Approaches to ensure that the patterns are directly related to the function of the element and the design wavelength are discussed. A procedure to preserve the scale of the graphic output when it is transferred to another application is given. Examples of surfaces for a 100 mm effective focal length lens and an Alvarez surface are given. {copyright} {ital 1996 American Institute of Physics.}

  17. Development of an automatic block generation algorithm

    NASA Technical Reports Server (NTRS)

    Eberhardt, Scott; Kim, Byoungsoo

    1995-01-01

    A method for automatic multiblock grid generation is described. The method combines the modified advancing front method as a predictor with an elliptic scheme as a corrector. It advances a collection of cells by one cell height in the outward direction using modified advancing front method, and then corrects newly-obtained cell positions by solving elliptic equations. This predictor-corrector type scheme is repeatedly applied until the field of interest is filled with hexahedral grid cells. Given the configuration surface grid, the scheme produces block layouts as well as grid cells with overall smoothness as its output. The method saves human-time and reduces the burden on the user in generating grids for general 3D configurations. It is used to generate multiblock grids for wings in their high-lift configuration.

  18. Career Development Patterns and Values of Women School Administrators

    ERIC Educational Resources Information Center

    Loyola, Matilde Corazon Cristina A.

    2016-01-01

    Career development research has often explored gender differences in and development of career patterns. Women were traditionally sidelined from performing from full participation in society and have struggled for their civil rights and social freedoms by challenging the male-dominated social systems. In an age when women are now gaining strong…

  19. Staffing Patterns and State Mental Health Manpower Development.

    ERIC Educational Resources Information Center

    McCullough, Paul M., Comp.; McPheeters, Harold L., Comp.

    This publication presents adaptations of four papers given at a workshop on Staffing and Manpower Development, sponsored by the Mental Health Manpower Development project of the Southern Regional Education Board. The introduction delineates four dimensions to be considered in describing staffing patterns (organization, utilization, type, and…

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

    PubMed

    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

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

    PubMed

    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.

  2. Generational Patterns in Mexican Americans' Academic Performance in an Unwelcoming Political Context

    PubMed Central

    Moosmann, Danyel A. V.; Roosa, Mark W.; Knight, George P.

    2014-01-01

    Research has shown that immigrant students often do better academically than their U.S.-born peers from the same ethnic group but it is unclear whether this pattern holds for Mexican Americans. We examined the academic performance of four generations of Mexican American students from fifth to 10th grade looking for generation differences and explanations for them. Using data from 749 families, we tested a model with fifth grade variables that differed by generation as potential mediators linking student generation to 10th grade academic performance. Results showed that immigrants were academically behind at fifth grade but caught up by seventh. Only economic hardship mediated the long term relationship between student generation and 10th grade academic performance; maternal educational expectations and child language hassles, English usage, discrimination, and mainstream values helped explained the early academic deficit of immigrant children. The results identified potential targets for interventions to improve Mexican American students' academic performance. PMID:24578588

  3. Forecasting and evaluating patterns of energy development in southwestern Wyoming

    USGS Publications Warehouse

    Garman, Steven L.

    2015-01-01

    The effects of future oil and natural gas development in southwestern Wyoming on wildlife populations are topical to conservation of the sagebrush steppe ecosystem. To aid in understanding these potential effects, the U.S. Geological Survey developed an Energy Footprint simulation model that forecasts the amount and pattern of energy development under different assumptions of development rates and well-drilling methods. The simulated disturbance patterns produced by the footprint model are used to assess the potential effects on wildlife habitat and populations. A goal of this modeling effort is to use measures of energy production (number of simulated wells), well-pad and road-surface disturbance, and potential effects on wildlife to identify build-out designs that minimize the physical and ecological footprint of energy development for different levels of energy production and development costs.

  4. Flexibility of the axial central pattern generator network for locomotion in the salamander.

    PubMed

    Ryczko, D; Knüsel, J; Crespi, A; Lamarque, S; Mathou, A; Ijspeert, A J; Cabelguen, J M

    2015-03-15

    In tetrapods, limb and axial movements are coordinated during locomotion. It is well established that inter- and intralimb coordination show considerable variations during ongoing locomotion. Much less is known about the flexibility of the axial musculoskeletal system during locomotion and the neural mechanisms involved. Here we examined this issue in the salamander Pleurodeles waltlii, which is capable of locomotion in both aquatic and terrestrial environments. Kinematics of the trunk and electromyograms from the mid-trunk epaxial myotomes were recorded during four locomotor behaviors in freely moving animals. A similar approach was used during rhythmic struggling movements since this would give some insight into the flexibility of the axial motor system. Our results show that each of the forms of locomotion and the struggling behavior is characterized by a distinct combination of mid-trunk motor patterns and cycle durations. Using in vitro electrophysiological recordings in isolated spinal cords, we observed that the spinal networks activated with bath-applied N-methyl-d-aspartate could generate these axial motor patterns. In these isolated spinal cord preparations, the limb motor nerve activities were coordinated with each mid-trunk motor pattern. Furthermore, isolated mid-trunk spinal cords and hemicords could generate the mid-trunk motor patterns. This indicates that each side of the cord comprises a network able to generate coordinated axial motor activity. The roles of descending and sensory inputs in the behavior-related changes in axial motor coordination are discussed.

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

    SciTech Connect

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

    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.

  6. Cellular basis for singing motor pattern generation in the field cricket (Gryllus bimaculatus DeGeer)

    PubMed Central

    Schöneich, Stefan; Hedwig, Berthold

    2012-01-01

    The singing behavior of male crickets allows analyzing a central pattern generator (CPG) that was shaped by sexual selection for reliable production of species-specific communication signals. After localizing the essential ganglia for singing in Gryllus bimaculatus, we now studied the calling song CPG at the cellular level. Fictive singing was initiated by pharmacological brain stimulation. The motor pattern underlying syllables and chirps was recorded as alternating spike bursts of wing-opener and wing-closer motoneurons in a truncated wing nerve; it precisely reflected the natural calling song. During fictive singing, we intracellularly recorded and stained interneurons in thoracic and abdominal ganglia and tested their impact on the song pattern by intracellular current injections. We identified three interneurons of the metathoracic and first unfused abdominal ganglion that rhythmically de- and hyperpolarized in phase with the syllable pattern and spiked strictly before the wing-opener motoneurons. Depolarizing current injection in two of these opener interneurons caused additional rhythmic singing activity, which reliably reset the ongoing chirp rhythm. The closely intermeshing arborizations of the singing interneurons revealed the dorsal midline neuropiles of the metathoracic and three most anterior abdominal neuromeres as the anatomical location of singing pattern generation. In the same neuropiles, we also recorded several closer interneurons that rhythmically hyper- and depolarized in the syllable rhythm and spiked strictly before the wing-closer motoneurons. Some of them received pronounced inhibition at the beginning of each chirp. Hyperpolarizing current injection in the dendrite revealed postinhibitory rebound depolarization as one functional mechanism of central pattern generation in singing crickets. PMID:23170234

  7. Neural basis of singing in crickets: central pattern generation in abdominal ganglia

    NASA Astrophysics Data System (ADS)

    Schöneich, Stefan; Hedwig, Berthold

    2011-12-01

    The neural mechanisms underlying cricket singing behavior have been the focus of several studies, but the central pattern generator (CPG) for singing has not been localized conclusively. To test if the abdominal ganglia contribute to the singing motor pattern and to analyze if parts of the singing CPG are located in these ganglia, we systematically truncated the abdominal nerve cord of fictively singing crickets while recording the singing motor pattern from a front-wing nerve. Severing the connectives anywhere between terminal ganglion and abdominal ganglion A3 did not preclude singing, although the motor pattern became more variable and failure-prone as more ganglia were disconnected. Singing terminated immediately and permanently after transecting the connectives between the metathoracic ganglion complex and the first unfused abdominal ganglion A3. The contribution of abdominal ganglia for singing pattern generation was confirmed by intracellular interneuron recordings and current injections. During fictive singing, an ascending interneuron with its soma and dendrite in A3 depolarized rhythmically. It spiked 10 ms before the wing-opener activity and hyperpolarized in phase with the wing-closer activity. Depolarizing current injection elicited rhythmic membrane potential oscillations and spike bursts that elicited additional syllables and reliably reset the ongoing chirp rhythm. Our results disclose that the abdominal ganglion A3 is directly involved in generating the singing motor pattern, whereas the more posterior ganglia seem to provide only stabilizing feedback to the CPG circuit. Localizing the singing CPG in the anterior abdominal neuromeres now allows analyzing its circuitry at the level of identified interneurons in subsequent studies.

  8. TCM Pattern Questionnaire for Lateral Elbow Pain: Development of an Instrument via a Delphi Process.

    PubMed

    Gadau, Marcus; Zhang, Shi-Ping; Yeung, Wing-Fai; Bian, Zhao-Xiang; Lu, Ai-Ping

    2016-01-01

    Individualized acupuncture treatment has been practiced for pain therapy. This study used acupuncture treatment for lateral elbow pain (LEP) as an example to study the diagnostic practice of individualized acupuncture treatment. A provisional version of LEP pattern questionnaire was developed based on a recent systematic review on TCM pattern diagnosis for LEP. A Delphi panel of 33 clinical experts from seven different countries was formed, and the Delphi survey was conducted in Chinese and English language for two rounds. Consensus was achieved from all 26 panelists who responded to the second round on 243 items of the instrument, which included a 72-question-long questionnaire. The mean level of expert consensus on the items of the final questionnaire was 85%. Consensus was found on four TCM patterns that could underlie LEP, namely, the wind-cold-dampness pattern, the qi stagnation and blood stasis pattern, the dual deficiency of qi and blood pattern, and the retained dampness-heat pattern. A list of signs and symptoms indicating one of the four TCM patterns and a list of preferred treatment modalities for each pattern were also generated. Our instrument shows considerable content validity. Further validity and reliability studies are under way.

  9. TCM Pattern Questionnaire for Lateral Elbow Pain: Development of an Instrument via a Delphi Process.

    PubMed

    Gadau, Marcus; Zhang, Shi-Ping; Yeung, Wing-Fai; Bian, Zhao-Xiang; Lu, Ai-Ping

    2016-01-01

    Individualized acupuncture treatment has been practiced for pain therapy. This study used acupuncture treatment for lateral elbow pain (LEP) as an example to study the diagnostic practice of individualized acupuncture treatment. A provisional version of LEP pattern questionnaire was developed based on a recent systematic review on TCM pattern diagnosis for LEP. A Delphi panel of 33 clinical experts from seven different countries was formed, and the Delphi survey was conducted in Chinese and English language for two rounds. Consensus was achieved from all 26 panelists who responded to the second round on 243 items of the instrument, which included a 72-question-long questionnaire. The mean level of expert consensus on the items of the final questionnaire was 85%. Consensus was found on four TCM patterns that could underlie LEP, namely, the wind-cold-dampness pattern, the qi stagnation and blood stasis pattern, the dual deficiency of qi and blood pattern, and the retained dampness-heat pattern. A list of signs and symptoms indicating one of the four TCM patterns and a list of preferred treatment modalities for each pattern were also generated. Our instrument shows considerable content validity. Further validity and reliability studies are under way. PMID:27525024

  10. TCM Pattern Questionnaire for Lateral Elbow Pain: Development of an Instrument via a Delphi Process

    PubMed Central

    Bian, Zhao-Xiang

    2016-01-01

    Individualized acupuncture treatment has been practiced for pain therapy. This study used acupuncture treatment for lateral elbow pain (LEP) as an example to study the diagnostic practice of individualized acupuncture treatment. A provisional version of LEP pattern questionnaire was developed based on a recent systematic review on TCM pattern diagnosis for LEP. A Delphi panel of 33 clinical experts from seven different countries was formed, and the Delphi survey was conducted in Chinese and English language for two rounds. Consensus was achieved from all 26 panelists who responded to the second round on 243 items of the instrument, which included a 72-question-long questionnaire. The mean level of expert consensus on the items of the final questionnaire was 85%. Consensus was found on four TCM patterns that could underlie LEP, namely, the wind-cold-dampness pattern, the qi stagnation and blood stasis pattern, the dual deficiency of qi and blood pattern, and the retained dampness-heat pattern. A list of signs and symptoms indicating one of the four TCM patterns and a list of preferred treatment modalities for each pattern were also generated. Our instrument shows considerable content validity. Further validity and reliability studies are under way. PMID:27525024

  11. The contribution of a central pattern generator in a reflex-based neuromuscular model

    PubMed Central

    Dzeladini, Florin; van den Kieboom, Jesse; Ijspeert, Auke

    2014-01-01

    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 of a CPG as feedforward component in terms of gait modulation. PMID:25018712

  12. Coupling relationship between the central pattern generator and the cerebral cortex with time delay.

    PubMed

    Lu, Qiang

    2015-08-01

    Brain activity is a cooperative process among neurons and involves the coupling relationship, which is crucial to perform operational tasks in various specialized areas of the nervous system. A finite signal transmission speed along the axons results in a space-dependent time delay. The central pattern generator (CPG) can in principle produce basic locomotor rhythm in the absence of inputs from higher brain centers and peripheral sensory feedback. To study the dynamic performance of CPG with time delay and its coupling relationship with the cerebral cortex, a new CPG model with time delay and a model of the neural mass model (NMM) and the CPG are developed. The coupling model is based on biological experimental results. Bifurcation theories and maximal Lyapunov exponent are used to analyze the dynamic performance. From the results, some CPGs are suggested to be embedded in limbs and composed of the parameters space which corresponds to the one of the cerebral cortex. This embodiment of humans can reduce the burden of the brain and simplify the control of the locomotion. The results also show that the phase diagram of the CPG cannot keep the limit cycle, and that the state of the NMM becomes increasingly chaotic as time delay increases. This finding implies that a person with slow reaction can easily lose the stability of his or her locomotion.

  13. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect

    Tulsa Fluid Flow

    2008-08-31

    closure relation development for different flow conditions. Modeling studies were performed in two parts, Technology Assessment and Model Development and Enhancement. The results of the Technology assessment study indicated that the performance of the current state of the art two-phase flow models was poor especially for three-phase pipeline flow when compared with the existing data. As part of the model development and enhancement study, a new unified model for gas-oil-water three-phase pipe flow was developed. The new model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. An experimental program including three-phase gas-oil-water horizontal flow and two-phase horizontal and inclined oil-water flow testing was conducted utilizing a Tulsa University Fluid Flow Projects Three-phase Flow Facility. The experimental results were incorporated into the unified model as they became available, and model results were used to better focus and tailor the experimental study. Finally, during the Period 2, a new three-phase databank has been developed using the data generated during this project and additional data available in the literature. The unified model to predict the gas-oil-water three phase flow characteristics was tested by comparing the prediction results with the data. The results showed good agreements.

  14. Managerial Career Development and the Generational Confrontation

    ERIC Educational Resources Information Center

    Moment, David; Fisher, Dalmar

    1973-01-01

    The authors propose that the manager's total career life (total life space, middle level behavior alternatives subject to personal control, and interactive, interpersonal communication, focused on mutual career development) be considered in approaching career development, rather than artificially isolating segments of the individual's life. This…

  15. Design and development of thermoelectric generator

    SciTech Connect

    Prem Kumar, D. S. Mahajan, Ishan Vardhan Anbalagan, R. Mallik, Ramesh Chandra

    2014-04-24

    In this paper we discuss the fabrication, working and characteristics of a thermoelectric generator made up of p and n type semiconductor materials. The device consists of Fe{sub 0.2}Co{sub 3.8}Sb{sub 11.5}Te{sub 0.5} (zT = 1.04 at 818 K) as the n-type and Zn4Sb3 (zT=0.8 at 550 K) as the p-type material synthesized by vacuum hot press method. Carbon paste has been used to join the semiconductor legs to metal (Molybdenum) electrodes to reduce the contact resistance. The multi-couple (4 legs) generator results a maximum output power of 1.083 mW at a temperature difference of 240 K between the hot and cold sides. In this investigation, an I-V characteristic, maximum output power of the thermoelectric module is presented. The efficiency of thermoelectric module is obtained as η = 0.273 %.

  16. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments.

    PubMed

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin-Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development.

  17. Development of peptide-based patterns by laser transfer

    NASA Astrophysics Data System (ADS)

    Dinca, V.; Kasotakis, E.; Catherine, J.; Mourka, A.; Mitraki, A.; Popescu, A.; Dinescu, M.; Farsari, M.; Fotakis, C.

    2007-12-01

    Peptide-based arrays and patterns have provided a powerful tool in the study of protein recognition and function. A variety of applications have been identified, including the interactions between peptides-enzymes, peptides-proteins, peptides-DNA, peptides-small molecules and peptides-cells. One of the main and most critical unresolved issues is the generation of high-density arrays which maintain the biological function of the peptides. In this study, we employ nanosecond laser-induced forward transfer for the generation of high-density peptide arrays and patterns on modified glass surfaces. We show that peptide-based microarrays can be fabricated on solid surfaces and specifically recognized by appropriate fluorescent tags, with the transfer not affecting the ability of the peptides to form fibrils. These initial results are poised to the construction of larger peptide patterns as scaffolds for the incorporation and display of ligands critical for cell attachment and growth, or for the templating of inorganic materials.

  18. Inter-dependent tissue growth and Turing patterning in a model for long bone development

    NASA Astrophysics Data System (ADS)

    Tanaka, Simon; Iber, Dagmar

    2013-10-01

    The development of long bones requires a sophisticated spatial organization of cellular signalling, proliferation, and differentiation programs. How such spatial organization emerges on the growing long bone domain is still unresolved. Based on the reported biochemical interactions we developed a regulatory model for the core signalling factors IHH, PTCH1, and PTHrP and included two cell types, proliferating/resting chondrocytes and (pre-)hypertrophic chondrocytes. We show that the reported IHH-PTCH1 interaction gives rise to a Schnakenberg-type Turing kinetics, and that inclusion of PTHrP is important to achieve robust patterning when coupling patterning and tissue dynamics. The model reproduces relevant spatiotemporal gene expression patterns, as well as a number of relevant mutant phenotypes. In summary, we propose that a ligand-receptor based Turing mechanism may control the emergence of patterns during long bone development, with PTHrP as an important mediator to confer patterning robustness when the sensitive Turing system is coupled to the dynamics of a growing and differentiating tissue. We have previously shown that ligand-receptor based Turing mechanisms can also result from BMP-receptor, SHH-receptor, and GDNF-receptor interactions, and that these reproduce the wildtype and mutant patterns during digit formation in limbs and branching morphogenesis in lung and kidneys. Receptor-ligand interactions may thus constitute a general mechanism to generate Turing patterns in nature.

  19. Symmetry constraints during the development of anisotropic spinodal patterns

    PubMed Central

    Sánchez-Muñoz, Luis; del Campo, Adolfo; Fernández, José F.

    2016-01-01

    Spinodal decomposition is a phase-separation phenomenon occurring at non-equilibrium conditions. In isotropic materials, it is expected to improve the physical properties, in which modulated structures arise from a single system of spinodal waves. However, in anisotropic materials this process is controversial and not very well understood. Here, we report anisotropic spinodal decomposition patterns in single crystals of K-rich feldspar with macroscopic monoclinic 2/m symmetry. The periodicity of the spinodal waves at ~450 nm produces a blue iridescence, typical of the gemstone moonstone. Stripe patterns in the (010) plane, labyrinthine patterns in the (100) plane, and coexistence of the two patterns in the (110) plane are first resolved by scanning Rayleigh scattering microscopy. Two orthogonal systems of spinodal waves with the same periodicity are derived from the features and orientations of the patterns on the crystal surfaces. The orthogonality of the waves is related to the perpendicularity of the binary axis and the mirror plane. Thus, the spinodal patterns must be controlled by symmetry constraints during phase separation at early stages. Unusual and new properties could be developed in other anisotropic materials by thermal treatment inducing two orthogonal systems of periodic spinodal waves. PMID:26860067

  20. Next Generation LOCAD-PTS Cartridge Development

    NASA Technical Reports Server (NTRS)

    Morris, H.; Nutter, D.; Weite, E.; Wells, M.; Maule, J.; Damon, M.; Monaco, L.; Steele, A.; Wainwright, N.

    2008-01-01

    Future astrobiology exploration missions will require rapid, point-of-use techniques for surface science experiments and contamination monitoring. The Lab-On-a-Chip Application Development (LOCAD) team is developing operational instruments that advance spaceflight technologies to molecular-based methods. Currently, LOCAD-Portable Test System (PTS) is quantifying levels of the bacterial molecule endotoxin onboard the Internatioal Space Station. Future research and development will focus on more sensitive molecular techniques that expand the number of compounds detected to include beta-glucan from fungal cell walls.

  1. Expression patterns of FGF receptors in the developing mammalian cochlea

    PubMed Central

    Hayashi, Toshinori; Ray, Catherine A.; Younkins, Christa; Bermingham-McDonogh, Olivia

    2010-01-01

    Many studies have shown the importance of the fibroblast growth factor (FGF) family of factors in the development of the mammalian cochlea. There are four fibroblast growth factor receptors (FGFR1-4) and all four are expressed in the cochlea during development. While there are examples in the literature of expression patterns of some of the receptors at specific stages of cochlear development there has been no systematic study. We have assembled a full analysis of the patterns of receptor expression during cochlear development for all four Fgfrs using in situ hybridization. We have analyzed the expression patterns from E13.5 through post-natal ages. We find that Fgfr1, 2 and 3 are expressed in the epithelium of the cochlear duct and Fgfr4 is limited in its expression to the mesenchyme surrounding the duct. We compare the receptor expression pattern to markers of the sensory domain (p27kip1) and the early hair cells (math1). PMID:20131355

  2. The Reversal in Migration Patterns -- Some Rural Development Consequences.

    ERIC Educational Resources Information Center

    Ploch, Louis A.

    The reversal in migration patterns in the 1970's resulting in a net population flow from metropolitan (urban) to nonmetropolitan (rural) areas may have a variety of rural development consequences. Sizeable population increase in rural communities which traditionally have experienced net out-migration or very slow increases is evident in Maine…

  3. Experimental observation of multistability and dynamic attractors in silicon central pattern generators

    NASA Astrophysics Data System (ADS)

    Zhao, Le; Nogaret, Alain

    2015-11-01

    We report on the multistability of chaotic networks of silicon neurons and demonstrate how spatiotemporal sequences of voltage oscillations are selected with timed current stimuli. A three neuron central pattern generator was built by interconnecting Hodgkin-Huxley neurons with mutually inhibitory links mimicking gap junctions. By systematically varying the timing of current stimuli applied to individual neurons, we generate the phase lag maps of neuronal oscillators and study their dependence on the network connectivity. We identify up to six attractors consisting of triphasic sequences of unevenly spaced pulses propagating clockwise and anticlockwise. While confirming theoretical predictions, our experiments reveal more complex oscillatory patterns shaped by the ratio of the pulse width to the oscillation period. Our work contributes to validating the command neuron hypothesis.

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

    PubMed

    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.

  5. Guided corona generates wettability patterns that selectively direct cell attachment inside closed microchannels.

    PubMed

    Dixon, Angela; Takayama, Shuichi

    2010-10-01

    We present a method to create plasma mediated linear protein patterns along the lengths of simple one-inlet-one-outlet straight polydimethylsiloxane microchannels by biasing the delivery of corona discharge at the capillary openings. Pattern widths ranging from 500-1,000 microm were generated in 2 mm wide microchannels with lengths of 0.5, 1.0, or 1.5 cm. Corona-treated surfaces enabled the spatial alignment of C2C12 myoblasts to the adhesive protein-coated regions, facilitating myoblast differentiation into myotubes. Although limited in precision, this protein patterning technique offers the advantages of simplicity and low cost, making it attractive for educational and research environments that lack access to extensive microfabrication facilities. The results also provide a cautionary note to those using corona discharge to increase wettability of microchannels; the surface modification may not be uniform, even within single microchannels being treated depending on settings and positioning of the corona device tips.

  6. Reaction kinetics of non-reciprocal photo-base generator (NRPBG) patterning

    NASA Astrophysics Data System (ADS)

    Shykind, D.; Bristol, R.; Roberts, J.; Blackwell, J.; Borodovsky, Y.

    2010-04-01

    We present a simple reaction rate analysis of lithographic patterning using the Non-Reciprocal Photo Base Generation (NRPBG) scheme of Bristol (Bristol, et. al., to be published in Proceedings of the SPIE - The International Society for Optical Engineering, 2010, presentation 7639-4). Multistep reaction kinetics simulations demonstrate that the NRPBG scheme produces clear pitch division upon 193 nm double-exposure, over a range of photochemical reaction rate constants.

  7. 160 Mpx/Sec Laser Pattern Generator For Mask And Reticle Production

    NASA Astrophysics Data System (ADS)

    MacDonald, D. B.; Nagler, M.; Van Peski, C.; Whitney, T. R.

    1984-06-01

    A new Laser Pattern Generator (LPG) designed for reticle production was recently introduced by THE Semiconductor Equipment Corporation. The system uses HeCd laser radiation with a wavelength of 441.6 nm to expose commercial photoresist (e.g. AZ 1350J or AZ 1470). A writing rate of 160 Mpx/sec is achieved by parallel operation of sixteen (16) independently modulated channels. The binary light intensity distribution is controlled in each channel by acousto-optic modulation. The sixteen (16) independent chan-nels are brought to a common crossover and scanned simultaneously using a single acousto-optic deflector. Pattern data must be expanded into a pixel format in two steps due to the inherent writing speed of the LPG. Prior to run time, geometrical data is trans-lated from Electromask or Mann format into a compact vector format using an off-line preprocessing unit. The vector data is stored on a 300 Mbyte portable disk pack which has a nominal data transfer rate of 9.67 Mbits/sec. During run time, vector data is read from the disk and expanded in the real time processing unit to supply pixel data to the optical modulation system. The placement of data in the correct position is controlled by a laser interferometry system and a control computer. The LPG system throughput of 160 Mpx/ sec permits the writing of 100 mm x 100 mm rejicles with information equivalent to 10' optical pattern generator flashes in less than 30 minutes, independent of pat-tern complexity. Although the specified minimum geometry is 2.5 pm, patterns with 1 pm features have been resolved. The address resolution is 0.25 μm, and the individual beam spot size is 0.5 μm (FWHM). Examples of printed patterns are included.

  8. A method to engineer phase-encoded photon sieve for intensity pattern generations

    NASA Astrophysics Data System (ADS)

    Li, Zhenhua; Ma, Li; Gao, Yaru; Liu, Chunxiang; Xu, Shicai; Zhang, Meina; Cheng, Chuanfu

    2015-11-01

    We propose a novel type of photon sieve where phases of its sieved waves are encoded as radial positions of the pinholes and use such phase-encoded sieves for generating designed intensity patterns in Fresnel domain. The sieve pinholes are arranged around Fresnel-rings to eliminate the quadratic Fresnel phase factor of diffraction of the sieved waves, leading the wave propagation to be equivalent to Fraunhofer diffraction. The pinholes take constant size in this paper and realize equal amplitude in the multiple sieved waves. Their positions are adjusted radially from corresponding rings to encode wave phases, taking effect by resulting in different optical paths from them to the observation plane origin. Then along with wave propagation, the encoded phases are decoded and the required phase differences are obtained in the discrete waves. We first conduct numerical simulations to show satisfactory performance of such phase-encoded photon sieves in generating arbitrarily designed intensity patterns and describe the quality of the reconstructed patterns. Then for qualitatively verifying the phase-encoding method, we experimentally fabricate three such sieves with relatively small pinhole number and obtain the designed patterns.

  9. From spinal central pattern generators to cortical network: integrated BCI for walking rehabilitation.

    PubMed

    Cheron, G; Duvinage, M; De Saedeleer, C; Castermans, T; Bengoetxea, A; Petieau, M; Seetharaman, K; Hoellinger, T; Dan, B; Dutoit, T; Sylos Labini, F; Lacquaniti, F; Ivanenko, Y

    2012-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Symbol Character Generator Developed for Decwriter II

    SciTech Connect

    Sand, R.J.

    2001-03-15

    The versatile dot matrix printer of the DECwriter II was modified to enable printing of symbol characters., e.g., Greek letters and other symbol for mathematical expressions and units of measurement. This development involved the replacement of the read-only memory (ROM) units with erasable-programmable read-only memory (EPROM) units.

  12. ZERO EMISSION POWER GENERATION TECHNOLOGY DEVELOPMENT

    SciTech Connect

    Ronald Bischoff; Stephen Doyle

    2005-01-20

    Clean Energy Systems (CES) was previously funded by DOE's ''Vision 21'' program. This program provided a proof-of-concept demonstration that CES' novel gas generator (combustor) enabled production of electrical power from fossil fuels without pollution. CES has used current DOE funding for additional design study exercises which established the utility of the CES-cycle for retrofitting existing power plants for zero-emission operations and for incorporation in zero-emission, ''green field'' power plant concepts. DOE funding also helped define the suitability of existing steam turbine designs for use in the CES-cycle and explored the use of aero-derivative turbines for advanced power plant designs. This work is of interest to the California Energy Commission (CEC) and the Norwegian Ministry of Petroleum & Energy. California's air quality districts have significant non-attainment areas in which CES technology can help. CEC is currently funding a CES-cycle technology demonstration near Bakersfield, CA. The Norwegian government is supporting conceptual studies for a proposed 40 MW zero-emission power plant in Stavager, Norway which would use the CES-cycle. The latter project is called Zero-Emission Norwegian Gas (ZENG). In summary, current engineering studies: (1) supported engineering design of plant subsystems applicable for use with CES-cycle zero-emission power plants, and (2) documented the suitability and availability of steam turbines for use in CES-cycle power plants, with particular relevance to the Norwegian ZENG Project.

  13. Dictyostelium development shows a novel pattern of evolutionary conservation.

    PubMed

    Tian, Xiangjun; Strassmann, Joan E; Queller, David C

    2013-04-01

    von Baer's law states that early stages of animal development are the most conserved. More recent evidence supports a modified "hourglass" pattern in which an early but somewhat later stage is most conserved. Both patterns have been explained by the relative complexity of either temporal or spatial interactions; the greatest conservation and lowest evolvability occur at the time of the most complex interactions, because these cause larger effects that are harder for selection to alter. This general kind of explanation might apply universally across independent multicellular systems, as supported by the recent finding of the hourglass pattern in plants. We use RNA-seq expression data from the development of the slime mold Dictyostelium to demonstrate that it does not follow either of the two canonical patterns but instead tends to show the strongest conservation and weakest evolvability late in development. We propose that this is consistent with a version of the spatial constraints model, modified for organisms that never achieve a high degree of developmental modularity. PMID:23329689

  14. D-D neutron generator development at LBNL.

    PubMed

    Reijonen, J; Gicquel, F; Hahto, S K; King, M; Lou, T-P; Leung, K-N

    2005-01-01

    The plasma and ion source technology group in Lawrence Berkeley National Laboratory is developing advanced, next generation D-D neutron generators. There are three distinctive developments, which are discussed in this presentation, namely, multi-stage, accelerator-based axial neutron generator, high-output co-axial neutron generator and point source neutron generator. These generators employ RF-induction discharge to produce deuterium ions. The distinctive feature of RF-discharge is its capability to generate high atomic hydrogen species, high current densities and stable and long-life operation. The axial neutron generator is designed for applications that require fast pulsing together with medium to high D-D neutron output. The co-axial neutron generator is aimed for high neutron output with cw or pulsed operation, using either the D-D or D-T fusion reaction. The point source neutron generator is a new concept, utilizing a toroidal-shaped plasma generator. The beam is extracted from multiple apertures and focus to the target tube, which is located at the middle of the generator. This will generate a point source of D-D, T-T or D-T neutrons with high output flux. The latest development together with measured data will be discussed in this article.

  15. Career Development in Generation X. Myths and Realities.

    ERIC Educational Resources Information Center

    Lankard, Bettina A.

    Several myths relate to the question of whether Generation X, the population cohort following the Baby Boomers, has different values, work ethics, and attitudes toward work and career development. The first myth is that individuals in Generation X are slackers, lacking career drive and ambition. The reality is that Generation X may just view the…

  16. Building the backbone: the development and evolution of vertebral patterning.

    PubMed

    Fleming, Angeleen; Kishida, Marcia G; Kimmel, Charles B; Keynes, Roger J

    2015-05-15

    The segmented vertebral column comprises a repeat series of vertebrae, each consisting of two key components: the vertebral body (or centrum) and the vertebral arches. Despite being a defining feature of the vertebrates, much remains to be understood about vertebral development and evolution. Particular controversy surrounds whether vertebral component structures are homologous across vertebrates, how somite and vertebral patterning are connected, and the developmental origin of vertebral bone-mineralizing cells. Here, we assemble evidence from ichthyologists, palaeontologists and developmental biologists to consider these issues. Vertebral arch elements were present in early stem vertebrates, whereas centra arose later. We argue that centra are homologous among jawed vertebrates, and review evidence in teleosts that the notochord plays an instructive role in segmental patterning, alongside the somites, and contributes to mineralization. By clarifying the evolutionary relationship between centra and arches, and their varying modes of skeletal mineralization, we can better appreciate the detailed mechanisms that regulate and diversify vertebral patterning.

  17. Building the backbone: the development and evolution of vertebral patterning.

    PubMed

    Fleming, Angeleen; Kishida, Marcia G; Kimmel, Charles B; Keynes, Roger J

    2015-05-15

    The segmented vertebral column comprises a repeat series of vertebrae, each consisting of two key components: the vertebral body (or centrum) and the vertebral arches. Despite being a defining feature of the vertebrates, much remains to be understood about vertebral development and evolution. Particular controversy surrounds whether vertebral component structures are homologous across vertebrates, how somite and vertebral patterning are connected, and the developmental origin of vertebral bone-mineralizing cells. Here, we assemble evidence from ichthyologists, palaeontologists and developmental biologists to consider these issues. Vertebral arch elements were present in early stem vertebrates, whereas centra arose later. We argue that centra are homologous among jawed vertebrates, and review evidence in teleosts that the notochord plays an instructive role in segmental patterning, alongside the somites, and contributes to mineralization. By clarifying the evolutionary relationship between centra and arches, and their varying modes of skeletal mineralization, we can better appreciate the detailed mechanisms that regulate and diversify vertebral patterning. PMID:25968309

  18. Patterns of dental development in Homo, Australopithecus, Pan, and Gorilla.

    PubMed

    Smith, B H

    1994-07-01

    Smith ([1986] Nature 323:327-330) distinguished patterns of development of teeth of juvenile fossil hominids as being "more like humans" or "more like apes" based on statistical similarity to group standards. Here, this central tendency discrimination (CTD) is tested for its ability to recognize ape and human patterns of dental development in 789 subadult hominoids. Tooth development of a modern human sample (665 black southern Africans) was scored entirely by an outside investigator; pongid and fossil hominid samples (59 Pan, 50 Gorilla, and 14 fossil hominids) were scored by the author. The claim of Lampl et al. ([1993] Am. J. Phys. Anthropol. 90:113-127) that Smith's 1986 method succeeds in only 8% of human cases was not sustained. Figures for overall success of classification (87% humans, 68% apes) mask important effects of teeth sampled and age class. For humans, the power of CTD varied between 53% and 92% depending on the number and kind of teeth available--nearly that of a coin toss when data described only two nearby teeth, but quite successful with more teeth or distant teeth. For apes, only age class affected accuracy: "Infant" apes (M1 development < or = root cleft complete, unemerged) were usually classed as humans, probably because the present developmental standard for great apes is in substantial error under 3 years of age. "Juvenile" apes (M1 > or = root 1/4), however, were correctly discriminated in 87% of cases. Overall, CTD can be considered reliable (accuracy of 92% for humans and 88% for apes) when data contrast development of distant dental fields and subjects are juveniles (not infants). Restricting analysis of fossils to specimens satisfying these criteria, patterns of dental development of gracile australopithecines and Homo habilis remain classified with African apes. Those of Homo erectus and Neanderthals are classified with humans, suggesting that patterns of growth evolved substantially in the Hominidae. To standardize future research

  19. Control strategies of 3-cell Central Pattern Generator via global stimuli

    NASA Astrophysics Data System (ADS)

    Lozano, Álvaro; Rodríguez, Marcos; Barrio, Roberto

    2016-03-01

    The study of the synchronization patterns of small neuron networks that control several biological processes has become an interesting growing discipline. Some of these synchronization patterns of individual neurons are related to some undesirable neurological diseases, and they are believed to play a crucial role in the emergence of pathological rhythmic brain activity in different diseases, like Parkinson’s disease. We show how, with a suitable combination of short and weak global inhibitory and excitatory stimuli over the whole network, we can switch between different stable bursting patterns in small neuron networks (in our case a 3-neuron network). We develop a systematic study showing and explaining the effects of applying the pulses at different moments. Moreover, we compare the technique on a completely symmetric network and on a slightly perturbed one (a much more realistic situation). The present approach of using global stimuli may allow to avoid undesirable synchronization patterns with nonaggressive stimuli.

  20. Control strategies of 3-cell Central Pattern Generator via global stimuli

    PubMed Central

    Lozano, Álvaro; Rodríguez, Marcos; Barrio, Roberto

    2016-01-01

    The study of the synchronization patterns of small neuron networks that control several biological processes has become an interesting growing discipline. Some of these synchronization patterns of individual neurons are related to some undesirable neurological diseases, and they are believed to play a crucial role in the emergence of pathological rhythmic brain activity in different diseases, like Parkinson’s disease. We show how, with a suitable combination of short and weak global inhibitory and excitatory stimuli over the whole network, we can switch between different stable bursting patterns in small neuron networks (in our case a 3-neuron network). We develop a systematic study showing and explaining the effects of applying the pulses at different moments. Moreover, we compare the technique on a completely symmetric network and on a slightly perturbed one (a much more realistic situation). The present approach of using global stimuli may allow to avoid undesirable synchronization patterns with nonaggressive stimuli. PMID:27021970

  1. Developing the Next Generation of Geoscientists

    NASA Astrophysics Data System (ADS)

    Sparrow, E. B.; Kopplin, M. R.

    2012-12-01

    The Monitoring Seasons Through Global Learning Communities (Seasons and Biomes), an inquiry- and project- based program, works with K-12 teachers and their students worldwide to increase awareness and understanding of the Earth as a system, and the science process. Seasons and Biomes is one of four GLOBE (Global learning and Observations to Benefit the Environment, www.globe.gov) earth system science projects. Seasons and Biomes engage students in ongoing research investigations as way of learning science. We do this by conducting for teachers, professional development workshops that incorporate science content, best teaching practices (that include inquiry, integrating science with math, language and art, authentic assessments, concept mapping), a model for student scientific research, and an earth system science approach. Teachers learn and practice standardized measurement protocols developed by GLOBE in the following areas of investigations: atmosphere, hydrology, soils, phenology and land cover/biology, as well as those developed by Seasons and Biomes on ice seasonality (freeze-up and break-up of rivers and lakes), active layer/depth of soil freezing (frost tube), mosquitoes (larvae abundance and identification of mosquito vectors for malaria and dengue fever) and plant invasive species. They also learn how to enter data as well as access data on the GLOBE website. Teachers in turn teach and work with their students in doing authentic science, contribute data to ongoing research as well as conduct their own studies. During the workshops we also provide guidance and opportunity for early career scientists to share their research, work with teachers and mentor them as well as to develop measurement protocols pertinent to their research. Similarly we work with GLOBE Alumni, students who were in the GLOBE program when they were in primary and/or secondary schools and have graduated from college, yet are still very much inspired and dedicated to working with

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

    PubMed

    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

  3. The importance of structured noise in the generation of self-organizing tissue patterns through contact-mediated cell–cell signalling

    PubMed Central

    Cohen, Michael; Baum, Buzz; Miodownik, Mark

    2011-01-01

    Lateral inhibition provides the basis for a self-organizing patterning system in which distinct cell states emerge from an otherwise uniform field of cells. The development of the microchaete bristle pattern on the notum of the fruitfly, Drosophila melanogaster, has long served as a popular model of this process. We recently showed that this bristle pattern depends upon a population of dynamic, basal actin-based filopodia, which span multiple cell diameters. These protrusions establish transient signalling contacts between non-neighbouring cells, generating a type of structured noise that helps to yield a well-ordered and spaced pattern of bristles. Here, we develop a general model of protrusion-based patterning to analyse the role of noise in this process. Using a simple asynchronous cellular automata rule-based model we show that this type of structured noise drives the gradual refinement of lateral inhibition-mediated patterning, as the system moves towards a stable configuration in which cells expressing the inhibitory signal are near-optimally packed. By analysing the effects of introducing thresholds required for signal detection in this model of lateral inhibition, our study shows how filopodia-mediated cell–cell communication can generate complex patterns of spots and stripes, which, in the presence of signalling noise, align themselves across a patterning field. Thus, intermittent protrusion-based signalling has the potential to yield robust self-organizing tissue-wide patterns without the need to invoke diffusion-mediated signalling. PMID:21084342

  4. NEURONAL ACTION ON THE DEVELOPING BLOOD VESSEL PATTERN

    PubMed Central

    James, Jennifer M.; Mukouyama, Yoh-suke

    2011-01-01

    The nervous system relies on a highly specialized network of blood vessels for development and neuronal survival. Recent evidence suggests that both the central and peripheral nervous systems (CNS and PNS) employ multiple mechanisms to shape the vascular tree to meet its specific metabolic demands, such as promoting nerve-artery alignment in the PNS or the development the blood brain barrier in the CNS. In this article we discuss how the nervous system directly influences blood vessel patterning resulting in neuro-vascular congruence that is maintained throughout development and in the adult. PMID:21978864

  5. Kit signaling is required for development of coordinated motility patterns in zebrafish gastrointestinal tract.

    PubMed

    Rich, Adam; Gordon, Scott; Brown, Chris; Gibbons, Simon J; Schaefer, Katherine; Hennig, Grant; Farrugia, Gianrico

    2013-06-01

    Interstitial cells of Cajal (ICC) provide a pacemaker signal for coordinated motility patterns in the mammalian gastrointestinal (GI) tract. Kit signaling is required for development and maintenance of ICC, and these cells can be identified by Kit-like immunoreactivity. The zebrafish GI tract has two distinct ICC networks similar to mammals, suggesting a similar role in the generation of GI motility; however, a functional role for Kit-positive cells in zebrafish has not been determined. Analysis of GI motility in intact zebrafish larvae was performed during development and after disruption of Kit signaling. Development of coordinated motility patterns occurred after 5 days post-fertilization (dpf) and correlated with appearance of Kit-positive cells. Disruptions of Kit signaling using the Kit antagonist imatinib mesylate, and in Sparse, a null kita mutant, also disrupted development of coordinated motility patterns. These data suggest that Kit signaling is necessary for development of coordinated motility patterns and that Kit-positive cells in zebrafish are necessary for coordinated motility patterns.

  6. Ultrastructure of stomatal development in early-divergent angiosperms reveals contrasting patterning and pre-patterning

    PubMed Central

    Rudall, Paula J.; Knowles, Emma V. W.

    2013-01-01

    Background and Aims Angiosperm stomata consistently possess a pair of guard cells, but differ between taxa in the patterning and developmental origin of neighbour cells. Developmental studies of phylogenetically pivotal taxa are essential as comparative yardsticks for understanding the evolution of stomatal development. Methods We present a novel ultrastructural study of developing stomata in leaves of Amborella (Amborellales), Nymphaea and Cabomba (Nymphaeales), and Austrobaileya and Schisandra (Austrobaileyales), representing the three earliest-divergent lineages of extant angiosperms (the ANITA-grade). Key Results Alternative developmental pathways occur in early-divergent angiosperms, resulting partly from differences in pre-patterning and partly from the presence or absence of highly polarized (asymmetric) mitoses in the stomatal cell lineage. Amplifying divisions are absent from ANITA-grade taxa, indicating that ostensible similarities with the stomatal patterning of Arabidopsis are superficial. In Amborella, ‘squared’ pre-patterning occurs in intercostal regions, with groups of four protodermal cells typically arranged in a rectangle; most guard-mother cells are formed by asymmetric division of a precursor cell (the mesoperigenous condition) and are typically triangular or trapezoidal. In contrast, water-lily stomata are always perigenous (lacking asymmetric divisions). Austrobaileya has occasional ‘giant’ stomata. Conclusions Similar mature stomatal phenotypes can result from contrasting morphogenetic factors, although the results suggest that paracytic stomata are invariably the product of at least one asymmetric division. Loss of asymmetric divisions in stomatal development could be a significant factor in land plant evolution, with implications for the diversity of key structural and physiological pathways. PMID:23969762

  7. EMAGE: a spatial database of gene expression patterns during mouse embryo development

    PubMed Central

    Christiansen, Jeffrey H.; Yang, Yiya; Venkataraman, Shanmugasundaram; Richardson, Lorna; Stevenson, Peter; Burton, Nicholas; Baldock, Richard A.; Davidson, Duncan R.

    2006-01-01

    EMAGE () is a freely available, curated database of gene expression patterns generated by in situ techniques in the developing mouse embryo. It is unique in that it contains standardized spatial representations of the sites of gene expression for each gene, denoted against a set of virtual reference embryo models. As such, the data can be interrogated in a novel and abstract manner by using space to define a query. Accompanying the spatial representations of gene expression patterns are text descriptions of the sites of expression, which also allows searching of the data by more conventional text-based methods. PMID:16381949

  8. Development of respiratory rhythm generation in ectothermic vertebrates.

    PubMed

    Hedrick, Michael S

    2005-11-15

    Compared with birds and mammals, very little is known about the development and regulation of respiratory rhythm generation in ectothermic vertebrates. The development and regulation of respiratory rhythm generation in ectothermic vertebrates (fish, amphibians and reptiles) should provide insight into the evolution of these mechanisms. One useful model for examining the development of respiratory rhythm generation in ectothermic vertebrates has emerged from studies with the North American bullfrog (Rana catesbeiana). A major advantage of bullfrogs as a comparative model for respiratory rhythm generation is that respiratory output may be measured at all stages of development, both in vivo and in vitro. An emerging view of recent studies in developing bullfrogs is that many of the mechanisms of respiratory rhythm generation are very similar to those seen in birds and mammals. The overall conclusion from these studies is that respiratory rhythm generation during development may be highly conserved during evolution. The development of respiratory rhythm generation in mammals may, therefore, reflect the antecedent mechanisms seen in ectothermic vertebrates. The main focus of this brief review is to discuss recent data on the development of respiratory rhythm generation in ectothermic vertebrates, with particular emphasis on the North American bullfrog (R. catesbeiana) as a model. PMID:15914099

  9. Target Development for Radioactive Ion Beam Generation

    NASA Astrophysics Data System (ADS)

    Kronenberg, A.; Carter, H. K.; Stracener, D. W.; Bilheux, J. C.; Cizewski, J. A.; Koester, U.

    2004-10-01

    Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. For example, ^82Ge,^130+xSn, ^92,94,95Sr beams are of interest but impurities and low intensities have prevented them from being useful. The code HSC-5 [1], with an extensive thermochemical database, predicts which chemical compounds may be transported within the target-ion source. The code also allows us to predict stability of target materials as function of temperature and pressure. So, a number of new targets have been fabricated and tested for use at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, based on the ISOL technique. Recent results from off-line and on-line tests at HRIBF and CERN-ISOLDE will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143. [1] HSC Chemistry for Windows - Chemical Reaction and Equilibrium Software with extensive Thermochemical Database, Outokumpu Research Oy, Pori, Finnland

  10. Target Development for Radioactive Ion Beam Generation

    NASA Astrophysics Data System (ADS)

    Kronenberg, A.; Carter, H. K.; Stracener, D.; Bilheux, J.; Cizewski, J. A.; Koester, U.

    2004-11-01

    Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. For example, ^82Ge, ^130+xSn, ^92,94,95Sr beams are of interest but impurities and low intensities have prevented them from being useful. The code HSC-5 [1], with an extensive thermochemical database predicts which chemical compounds may be transported within the target-ion source. The code also allows us to predict stability of target materials as function of temperature and pressure. So, a number of new targets have been fabricated and tested for use at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, based on the ISOL technique. Recent results from off-line and on-line tests at HRIBF and CERN-ISOLDE will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143. [1] HSC Chemistry for Windows Chemical Reaction and Equilibrium Software with extensive Thermochemical Database, Outokumpu Research Oy, Pori, Finnland

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

    PubMed

    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

  12. Characterization of sacral interneurons that mediate activation of locomotor pattern generators by sacrocaudal afferent input.

    PubMed

    Etlin, Alex; Finkel, Eran; Mor, Yoav; O'Donovan, Michael J; Anglister, Lili; Lev-Tov, Aharon

    2013-01-01

    Identification of the neural pathways involved in retraining the spinal central pattern generators (CPGs) by afferent input in the absence of descending supraspinal control is feasible in isolated rodent spinal cords where the locomotor CPGs are potently activated by sacrocaudal afferent (SCA) input. Here we study the involvement of sacral neurons projecting rostrally through the ventral funiculi (VF) in activation of the CPGs by sensory stimulation. Fluorescent labeling and immunostaining showed that VF neurons are innervated by primary afferents immunoreactive for vesicular glutamate transporters 1 and 2 and by intraspinal neurons. Calcium imaging revealed that 55% of the VF neurons were activated by SCA stimulation. The activity of VF neurons and the sacral and lumbar CPGs was abolished when non-NMDA receptors in the sacral segments were blocked by the antagonist CNQX. When sacral NMDA receptors were blocked by APV, the sacral CPGs were suppressed, VF neurons with nonrhythmic activity were recruited and a moderate-drive locomotor rhythm developed during SCA stimulation. In contrast, when the sacral CPGs were activated by SCA stimulation, rhythmic and nonrhythmic VF neurons were recruited and the locomotor rhythm was most powerful. The activity of 73 and 27% of the rhythmic VF neurons was in-phase with the ipsilateral and contralateral motor output, respectively. Collectively, our studies indicate that sacral VF neurons serve as a major link between SCA and the hindlimb CPGs and that the ability of SCA to induce stepping can be enhanced by the sacral CPGs. The nature of the ascending drive to lumbar CPGs, the identity of subpopulations of VF neurons, and their potential role in activating the locomotor rhythm are discussed. PMID:23303951

  13. Brain development and aging: overlapping and unique patterns of change.

    PubMed

    Tamnes, Christian K; Walhovd, Kristine B; Dale, Anders M; Østby, Ylva; Grydeland, Håkon; Richardson, George; Westlye, Lars T; Roddey, J Cooper; Hagler, Donald J; Due-Tønnessen, Paulina; Holland, Dominic; Fjell, Anders M

    2013-03-01

    Early-life development is characterized by dramatic changes, impacting lifespan function more than changes in any other period. Developmental origins of neurocognitive late-life functions are acknowledged, but detailed longitudinal magnetic resonance imaging studies of brain maturation and direct comparisons with aging are lacking. To these aims, a novel method was used to measure longitudinal volume changes in development (n=85, 8-22 years) and aging (n=142, 60-91 years). Developmental reductions exceeded 1% annually in much of the cortex, more than double to that seen in aging, with a posterior-to-anterior gradient. Cortical reductions were greater than the subcortical during development, while the opposite held in aging. The pattern of lateral cortical changes was similar across development and aging, but the pronounced medial temporal reduction in aging was not precast in development. Converging patterns of change in adolescents and elderly, particularly in the medial prefrontal areas, suggest that late developed cortices are especially vulnerable to atrophy in aging. A key question in future research will be to disentangle the neurobiological underpinnings for the differences and the similarities between brain changes in development and aging. PMID:23246860

  14. A plausible mechanism for auxin patterning along the developing root

    PubMed Central

    2010-01-01

    Background In plant roots, auxin is critical for patterning and morphogenesis. It regulates cell elongation and division, the development and maintenance of root apical meristems, and other processes. In Arabidopsis, auxin distribution along the central root axis has several maxima: in the root tip, in the basal meristem and at the shoot/root junction. The distal maximum in the root tip maintains the stem cell niche. Proximal maxima may trigger lateral or adventitious root initiation. Results We propose a reflected flow mechanism for the formation of the auxin maximum in the root apical meristem. The mechanism is based on auxin's known activation and inhibition of expressed PIN family auxin carriers at low and high auxin levels, respectively. Simulations showed that these regulatory interactions are sufficient for self-organization of the auxin distribution pattern along the central root axis under varying conditions. The mathematical model was extended with rules for discontinuous cell dynamics so that cell divisions were also governed by auxin, and by another morphogen Division Factor which combines the actions of cytokinin and ethylene on cell division in the root. The positional information specified by the gradients of these two morphogens is able to explain root patterning along the central root axis. Conclusion We present here a plausible mechanism for auxin patterning along the developing root, that may provide for self-organization of the distal auxin maximum when the reverse fountain has not yet been formed or has been disrupted. In addition, the proximal maxima are formed under the reflected flow mechanism in response to periods of increasing auxin flow from the growing shoot. These events may predetermine lateral root initiation in a rhyzotactic pattern. Another outcome of the reflected flow mechanism - the predominance of lateral or adventitious roots in different plant species - may be based on the different efficiencies with which auxin inhibits its

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

    PubMed

    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.

  16. Development of walking pattern evaluation system for hypogravity simulation.

    PubMed

    Leães, R; Cambraia, R; Bacim, F; Dalmarco, G; Calder, A; De Azevedo, D F G; Pinho, M; Russomano, T

    2006-01-01

    This study aimed to develop a Walking Pattern Evaluation System during Hypogravity Simulation (SAMSH), which included the adaptation of a body suspension device, the instrumentation of a treadmill and the development of a virtual environment. SAMSH was developed using one subject. Kinematic analyses were performed whilst one individual was walking on the treadmill during body weight reduction simulating the gravitational forces of the Moon (reduction of 60%) and Mars (reduction of 30%) with and without virtual reality glasses (Head Mounted Display, HMD). The walking pattern was evaluated by means of knee and ankle electrogoniometers, foot switches placed on the front and back part of the plantar region, and five video cameras. Results showed that the body weight reduction during Moon simulation alter the walking pattern, including the increase in step time, contact time, step length and aerial time, and the decrease of walking cadence time (steps per minute). The findings of this study also suggested that hypogravity simulation reduces walking effort. The utilization of the HMD allowed the evaluation of the head position three-dimensionally during hypogravity simulation. The virtual environment reduced postural balance, due to the absence of visual input, which was evidenced by a protective extension reaction.

  17. [Central Pattern Generators: Mechanisms of the Activity and Their Role in the Control of "Automatic" Movements].

    PubMed

    Arshavsky, I; Deliagina, T G; Orlovsky, G N

    2015-01-01

    Central pattern generators (CPGs) are a set of interconnected neurons capable of generating a basic pattern of motor output underlying "automatic" movements (breathing, locomotion, chewing, swallowing, and so on) in the absence of afferent signals from the executive motor apparatus. They can be divided into the constitutive CPGs active throughout the entire lifetime (respiratory CPGs) and conditional CPGs controlling episodic movements (locomotion, chewing, swallowing, and others). Since a motor output of CPGs is determined by their internal organization, the activities of the conditional CPGs are initiated by simple commands coming from higher centers. We describe the structural and functional organization of the locomotor CPGs in the marine mollusk Clione limacina, lamprey, frog embryo, and laboratory mammals (cat, mouse, and rat), CPGs controlling the respiratory and swallowing movements in mammals, and CPGs controlling discharges of the electric organ in the gymnotiform fish. It is shown that in all these cases, the generation of rhythmic motor output is based both on the endogenous (pacemaker) activity of specific groups of interneurons and on interneural interactions. These two interrelated mechanisms complement each other, ensuring the high reliability of CPG functionality. We discuss how the experience obtained in studying CPGs can be used to understand mechanisms of more complex functions of the brain, including its cognitive functions.

  18. Familial bias and auditory feedback regulation of vocal babbling patterns during early song development

    PubMed Central

    Sato, Daisuke; Mori, Chihiro; Sawai, Azusa; Wada, Kazuhiro

    2016-01-01

    Learned vocalizations are a crucial acoustic biosignal conveying individual traits in many species. Songbirds learn song patterns by listening to a tutor song and performing vocal practice during a sensitive developmental period. However, when and how individual differences in song patterns develop remain unknown. Here, we report that individual differences in vocal output exist even at the earliest song development stage, called subsong. Experiments involving the manipulation of both breeding pairs and song tutoring conditions revealed that the parental pair combination contributes to generating familial differences in syllable duration and variability in the subsong of offspring. Furthermore, after deafening, juveniles immediately changed their subsong by shortening the syllable durations but maintained the individual variability of their subsong temporal patterns, suggesting both auditory-sensitive modification and independent intrinsic regulation of vocal output. These results indicate that the temporal patterns of subsong are not merely disordered vocalization but are regulated by familial bias with sensitivity to auditory feedback, thus generating individual variability at the initiation of vocal development. PMID:27444993

  19. Generation pattern of sulfur containing gases from anaerobically digested sludge cakes.

    PubMed

    Novak, John T; Adams, Gregory; Chen, Yen-Chih; Erdal, Zeynep; Forbes, Robert H; Glindemann, Dietmar; Hargreaves, J Ronald; Hentz, Lawrence; Higgins, Matthew J; Murthy, Sudhir N; Witherspoon, Jay

    2006-08-01

    Eleven dewatered sludge cakes collected from anaerobic digesters at different treatment plants were evaluated for the amount, type, and pattern of odorous gas production. All but one of the sludge cakes were from mesophilic anaerobic digesters. One was from a thermophilic digester. The pattern and quantities of sulfur gases were found to be unique for each of the samples with regard to the products produced, magnitude, and subsequent decline. The main odor-causing chemicals were volatile sulfur compounds, which included hydrogen sulfide, methanethiol, and dimethyl sulfide. Volatile sulfur compound production peaked in 3 to 8 days and then declined. The decline was a result of conversion of organic sulfur compounds to sulfide. In one side-by-side test, a high-solids centrifuge cake generated more odorous compounds than the low-solids centrifuge cake. The data show that anaerobic digestion does not eliminate the odor potential of anaerobically digested dewatered cakes.

  20. Geometric Morphometrics on Gene Expression Patterns Within Phenotypes: A Case Example on Limb Development

    PubMed Central

    Martínez-Abadías, Neus; Mateu, Roger; Niksic, Martina; Russo, Lucia; Sharpe, James

    2016-01-01

    How the genotype translates into the phenotype through development is critical to fully understand the evolution of phenotypes. We propose a novel approach to directly assess how changes in gene expression patterns are associated with changes in morphology using the limb as a case example. Our method combines molecular biology techniques, such as whole-mount in situ hybridization, with image and shape analysis, extending the use of Geometric Morphometrics to the analysis of nonanatomical shapes, such as gene expression domains. Elliptical Fourier and Procrustes-based semilandmark analyses were used to analyze the variation and covariation patterns of the limb bud shape with the expression patterns of two relevant genes for limb morphogenesis, Hoxa11 and Hoxa13. We devised a multiple thresholding method to semiautomatically segment gene domains at several expression levels in large samples of limb buds from C57Bl6 mouse embryos between 10 and 12 postfertilization days. Besides providing an accurate phenotyping tool to quantify the spatiotemporal dynamics of gene expression patterns within developing structures, our morphometric analyses revealed high, non-random, and gene-specific variation undergoing canalization during limb development. Our results demonstrate that Hoxa11 and Hoxa13, despite being paralogs with analogous functions in limb patterning, show clearly distinct dynamic patterns, both in shape and size, and are associated differently with the limb bud shape. The correspondence between our results and already well-established molecular processes underlying limb development confirms that this morphometric approach is a powerful tool to extract features of development regulating morphogenesis. Such multilevel analyses are promising in systems where not so much molecular information is available and will advance our understanding of the genotype–phenotype map. In systematics, this knowledge will increase our ability to infer how evolution modified a common

  1. Cellular and muscular growth patterns during sipunculan development.

    PubMed

    Kristof, Alen; Wollesen, Tim; Maiorova, Anastassya S; Wanninger, Andreas

    2011-05-15

    Sipuncula is a lophotrochozoan taxon with annelid affinities, albeit lacking segmentation of the adult body. Here, we present data on cell proliferation and myogenesis during development of three sipunculan species, Phascolosoma agassizii, Thysanocardia nigra, and Themiste pyroides. The first anlagen of the circular body wall muscles appear simultaneously and not subsequently as in the annelids. At the same time, the rudiments of four longitudinal retractor muscles appear. This supports the notion that four introvert retractors were part of the ancestral sipunculan bodyplan. The longitudinal muscle fibers form a pattern of densely arranged fibers around the retractor muscles, indicating that the latter evolved from modified longitudinal body wall muscles. For a short time interval, the distribution of S-phase mitotic cells shows a metameric pattern in the developing ventral nerve cord during the pelagosphera stage. This pattern disappears close to metamorphic competence. Our findings are congruent with data on sipunculan neurogenesis, as well as with recent molecular analyses that place Sipuncula within Annelida, and thus strongly support a segmental ancestry of Sipuncula. PMID:21246707

  2. Ca2+ signalling and early embryonic patterning during zebrafish development.

    PubMed

    Webb, Sarah E; Miller, Andrew L

    2007-09-01

    1. It has been proposed that Ca2+ signalling, in the form of pulses, waves and steady gradients, may play a crucial role in key pattern-forming events during early vertebrate development. 2. With reference to the embryo of the zebrafish (Danio rerio), herein we review the Ca2+ transients reported from the cleavage to segmentation periods. This time-window includes most of the major pattern-forming events of early development, which transform a single-cell zygote into a complex multicellular embryo with established primary germ layers and body axes. 3. Data are presented to support our proposal that intracellular Ca2+ waves are an essential feature of embryonic cytokinesis and that propagating intercellular Ca2+ waves (both long and short range) may play a crucial role in: (i) the establishment of the embryonic periderm and the coordination of cell movements during epiboly, convergence and extension; (ii) the establishment of the basic embryonic axes and germ layers; and (iii) definition of the morphological boundaries of specific tissue domains and embryonic structures, including future organ anlagen. 4. The potential downstream targets of these Ca2+ transients are also discussed, as well as how they may integrate with other pattern-forming signalling pathways known to modulate early developmental events.

  3. Cellular and Muscular Growth Patterns During Sipunculan Development

    PubMed Central

    KRISTOF, ALEN; WOLLESEN, TIM; MAIOROVA, ANASTASSYA S.; WANNINGER, ANDREAS

    2015-01-01

    Sipuncula is a lophotrochozoan taxon with annelid affinities, albeit lacking segmentation of the adult body. Here, we present data on cell proliferation and myogenesis during development of three sipunculan species, Phascolosoma agassizii, Thysanocardia nigra, and Themiste pyroides. The first anlagen of the circular body wall muscles appear simultaneously and not subsequently as in the annelids. At the same time, the rudiments of four longitudinal retractor muscles appear. This supports the notion that four introvert retractors were part of the ancestral sipunculan bodyplan. The longitudinal muscle fibers form a pattern of densely arranged fibers around the retractor muscles, indicating that the latter evolved from modified longitudinal body wall muscles. For a short time interval, the distribution of S-phase mitotic cells shows a metameric pattern in the developing ventral nerve cord during the pelagosphera stage. This pattern disappears close to metamorphic competence. Our findings are congruent with data on sipunculan neurogenesis, as well as with recent molecular analyses that place Sipuncula within Annelida, and thus strongly support a segmental ancestry of Sipuncula. PMID:21246707

  4. Multiplexed recording with uncorrelated computer-generated reference patterns in coaxial holographic data storage.

    PubMed

    Nobukawa, Teruyoshi; Wani, Yotaro; Nomura, Takanori

    2015-05-15

    A computer-generated reference pattern (CGRP) allows improvement in light efficiency and the quality of reconstructed data in coaxial holographic data storage. In this Letter, a multiplexed recording method with uncorrelated CGRPs is proposed. With this method, crosstalk from adjacent holograms is suppressed without shifting a medium. To confirm the feasibility of the proposed method experimentally, shift selectivity is investigated, and then multiplexed recording is performed. Experimental results show that the proposed method enables high-density recording compared with conventional shift multiplexing. In addition, a theoretical analysis implies that at least 100 uncorrelated CGRPs can be designed and used for multiplexed recording. PMID:26393689

  5. Connection and coordination: the interplay between architecture and dynamics in evolved model pattern generators.

    PubMed

    Psujek, Sean; Ames, Jeffrey; Beer, Randall D

    2006-03-01

    We undertake a systematic study of the role of neural architecture in shaping the dynamics of evolved model pattern generators for a walking task. First, we consider the minimum number of connections necessary to achieve high performance on this task. Next, we identify architectural motifs associated with high fitness. We then examine how high-fitness architectures differ in their ability to evolve. Finally, we demonstrate the existence of distinct parameter subgroups in some architectures and show that these subgroups are characterized by differences in neuron excitabilities and connection signs. PMID:16483415

  6. Forest stand development patterns in the southern Appalachians

    SciTech Connect

    Copenheaver, C.A.; Matthews, J.M.; Showalter, J.M.; Auch, W.E.

    2006-07-01

    Composition of southern Appalachian forests are influenced by disturbance and topography. This study examined six stands in southwestern Virginia. Within each stand, a 0.3-ha plot was established, and all trees and saplings were measured and aged. Burned stands had lower densities of saplings and small trees, but appeared to have greater Quercus regeneration. Ice damage from the 1994 ice storm was most evident in Pinus strobus saplings. A stand on old coal-mine slag appeared to be experiencing a slower rate of succession than other sites. A variety of stand development patterns were observed, but one common pattern was that oak-hickory overstories had different species in their understory, which may indicate future changes in species composition.

  7. A flight study of tone radiation patterns generated by inlet rods in a small turbofan engine

    NASA Astrophysics Data System (ADS)

    Preisser, J. S.; Silcox, R. J.; Eversman, W.; Parrett, A. V.

    1984-01-01

    This paper presents a flight study of tone radiation patterns from a small turbofan engine and compares results with similar static test stand data and a recently developed radiation theory. An interaction tone was produced by a circumferential array of inlet rods placed just upstream of the fan blades. Overhead and sideline flight directivity patterns showed cut-on of a dominant single mode occurred where predicted and the absence of any other significant circumferential or radial modes. In general, good agreement was found between measured flight and static data, with small differences being attributed to inlet geometry and/or forward speed effects. Good agreement was also obtained between flight data and theory for directivity pattern shape, however, the theory consistently predicted higher values for peak radiation angle over a wide range of frequency.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Search for complexity generating chemical transformations by combining connectivity analysis and cascade transformation patterns.

    PubMed

    Nowak, Grazyna; Fic, Grzegorz

    2010-08-23

    Retrosynthetic analysis involved in a backward search for strategic disconnections is still the most powerful strategy, recently advanced by topology-based complexity estimation, for discovering the shortest sequences of transformations and chemical synthesis planning. Therein, we propose an alternative strategy that combines backward and forward search embodied within a mathematical model of generating chemical transformations. The backward reasoning involves a new concept of the strategic bond tree for alternative multibond disconnections of a target molecule. In the forward direction, each combination of the resulted structural fragments is examined for reconstruction of the target structure by means of biomimetic transformation patterns that describe one-pot multibond forming reactions. The algorithm has been implemented into the CSB system, and its performance is illustrated by examples of published complex molecule syntheses for comparison and analysis. This paper describes the strategy for discovering the shortest synthetic pathways based on the multibond forming cascade transformations for application in synthesis design and generating synthetically accessible product libraries.

  10. Caregiving Practice Patterns of Asian, Hispanic, and Non-Hispanic White American Family Caregivers of Older Adults Across Generations.

    PubMed

    Miyawaki, Christina E

    2016-03-01

    This study is a cross-sectional investigation of caregiving practice patterns among Asian, Hispanic and non-Hispanic White American family caregivers of older adults across three immigrant generations. The 2009 California Health Interview Survey (CHIS) dataset was used, and 591 Asian, 989 Hispanic and 6537 non-Hispanic White American caregivers of older adults were selected. First, descriptive analyses of caregivers' characteristics, caregiving situations and practice patterns were examined by racial/ethnic groups and immigrant generations. Practice patterns measured were respite care use, hours and length of caregiving. Three hypotheses on caregiving patterns based on assimilation theory were tested and analyzed using logistic regression and generalized linear models by racial/ethnic groups and generations. Caregiving patterns of non-Hispanic White caregivers supported all three hypotheses regarding respite care use, caregiving hours and caregiving duration, showing less caregiving involvement in later generations. However, Asian and Hispanic counterparts showed mixed results. Third generation Asian and Hispanic caregivers used respite care the least and spent the most caregiving hours per week and had the longest caregiving duration compared to earlier generations. These caregiving patterns revealed underlying cultural values related to filial responsibility, even among later generations of caregivers of color. Findings suggest the importance of considering the cultural values of each racial/ethnic group regardless of generation when working with racially and ethnically diverse populations of family caregivers of older adults.

  11. Development and Test of a Prototype 100MVA Superconducting Generator

    SciTech Connect

    Fogarty, James M.; Bray, James W.

    2007-05-25

    In 2002, General Electric and the US Department of Energy (DOE) entered into a cooperative agreement for the development of a commercialized 100 MVA generator using high temperature superconductors (HTS) in the field winding. The intent of the program was to: • Identify and develop technologies that would be needed for such a generator. • Develop conceptual designs for generators with ratings of 100 MVA and higher using HTS technology. • Perform proof of concept tests at the 1.5 MW level for GE’s proprietary warm iron rotor HTS generator concept. • Design, build, and test a prototype of a commercially viable 100 MVA generator that could be placed on the power grid. This report summarizes work performed during the program and is provided as one of the final program deliverables.

  12. Patterns of physical and psychological development in future teenage mothers

    PubMed Central

    Nettle, Daniel; Dickins, Thomas E.; Coall, David A.; de Mornay Davies, Paul

    2013-01-01

    Background and objectives: Teenage childbearing may have childhood origins and can be viewed as the outcome of a coherent reproductive strategy associated with early environmental conditions. Life-history theory would predict that where futures are uncertain fitness can be maximized through diverting effort from somatic development into reproduction. Even before the childbearing years, future teenage mothers differ from their peers both physically and psychologically, indicating early calibration to key ecological factors. Cohort data have not been deliberately collected to test life-history hypotheses within Western populations. Nonetheless, existing data sets can be used to pursue relevant patterns using socioeconomic variables as indices of relevant ecologies. Methodology: We examined the physical and psychological development of 599 young women from the National Child Development Study who became mothers before age 20, compared to 599 socioeconomically matched controls. Results: Future young mothers were lighter than controls at birth and shorter at age 7. They had earlier menarche and accelerated breast development, earlier cessation of growth and shorter adult stature. Future young mothers had poorer emotional and behavioural adjustment than controls at age 7 and especially 11, and by age 16, idealized younger ages for marriage and parenthood than did the controls. Conclusions and implications: The developmental patterns we observed are consistent with the idea that early childbearing is a component of an accelerated reproductive strategy that is induced by early-life conditions. We discuss the implications for the kinds of interventions likely to affect the rate of teenage childbearing. PMID:24481198

  13. Microfluidic-based patterning of embryonic stem cells for in vitro development studies.

    PubMed

    Suri, Shalu; Singh, Ankur; Nguyen, Anh H; Bratt-Leal, Andres M; McDevitt, Todd C; Lu, Hang

    2013-12-01

    In vitro recapitulation of mammalian embryogenesis and examination of the emerging behaviours of embryonic structures require both the means to engineer complexity and accurately assess phenotypes of multicellular aggregates. Current approaches to study multicellular populations in 3D configurations are limited by the inability to create complex (i.e. spatially heterogeneous) environments in a reproducible manner with high fidelity thus impeding the ability to engineer microenvironments and combinations of cells with similar complexity to that found during morphogenic processes such as development, remodelling and wound healing. Here, we develop a multicellular embryoid body (EB) fusion technique as a higher-throughput in vitro tool, compared to a manual assembly, to generate developmentally relevant embryonic patterns. We describe the physical principles of the EB fusion microfluidic device design; we demonstrate that >60 conjoined EBs can be generated overnight and emulate a development process analogous to mouse gastrulation during early embryogenesis. Using temporal delivery of bone morphogenic protein 4 (BMP4) to embryoid bodies, we recapitulate embryonic day 6.5 (E6.5) during mouse embryo development with induced mesoderm differentiation in murine embryonic stem cells leading to expression of Brachyury-T-green fluorescent protein (T-GFP), an indicator of primitive streak development and mesoderm differentiation during gastrulation. The proposed microfluidic approach could be used to manipulate hundreds or more of individual embryonic cell aggregates in a rapid fashion, thereby allowing controlled differentiation patterns in fused multicellular assemblies to generate complex yet spatially controlled microenvironments.

  14. Developments and trends in three-dimensional mesh generation

    NASA Technical Reports Server (NTRS)

    Baker, Timothy J.

    1989-01-01

    An intense research effort over the last few years has produced several competing and apparently diverse methods for generating meshes. Recent progress is reviewed and the central themes are emphasized which form a solid foundation for future developments in mesh generation.

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

    PubMed

    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.

  16. Helical Striation Pattern Generation and Axial Field Compression in Aluminum Liner Experiments at 1 MA

    NASA Astrophysics Data System (ADS)

    Atoyan, Levon; Byvank, Tom; Greenly, John; Kusse, Bruce; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Hammer, David

    2015-11-01

    Awe et al. [Phys. Plasmas 21, 235005, 2014] found on the 20 MA Z machine that applying an externally generated axial magnetic field to an imploding liner produces a helical plasma pattern near the surface of the liner. Here we show that this phenomenon is also observed using 10 mm long cylindrical metal liners having 16 mm diameter and 3 to 6 μm wall thickness on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The magnetic field in these experiments is created using a 150 μs rise time Helmholtz coil, and the pattern is observed using extreme ultraviolet imaging. Moreover, using B-dot probes we show that there is a 4-8% axial magnetic field compression relative to the initially applied Bz. Using a visible light framing camera, we show that this compression begins before the outside surface of the liner has become a visible light emitting plasma. This research was sponsored by the NNSA SSAP under DOE Coop Agreement DE-NA0001836 and DOE grant DE-NA0001847 as well as by NSF grant PHY-1102471.

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

    PubMed

    David, Izhak; Holmes, Philip; Ayali, Amir

    2016-09-15

    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.

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

    PubMed Central

    David, Izhak; Holmes, Philip

    2016-01-01

    ABSTRACT 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. PMID:27422902

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Scalable and enhanced triboelectric output power generation by surface functionalized nanoimprint patterns

    NASA Astrophysics Data System (ADS)

    Hyeog Kwon, Yang; Shin, Sung-Ho; Jung, Joo-Yun; Nah, Junghyo

    2016-05-01

    We report nanoimprint lithographic submicron surface patterning for scalable output power generation and performance enhancement in triboelectric nanogenerators (TENGs). Specifically, one contact surface of a TENG is nanoimprinted with polyurethane acrylate (PUA) lines in different pitches and the counter contact surface is coated with perfluoropolyether (PFPE). The results show that a TENG with 200 nm pitch PUA lines exhibits voltage and current up to ˜430 V and ˜55 μA cm-2, generating about a sixfold higher output power than that with a flat PUA surface at an applied force of 0.3 MPa. In addition, scalable output power was obtained by adjusting line pitches. Further enhancement in output power was also demonstrated by chemically functionalizing the PUA line patterns with poly (diallyldimethylammonium chloride) (PDDA). The PDDA functionalization boosted voltage and current up to ˜500 V and ˜100 μA cm-2, respectively, which corresponds to ˜50% power density enhancement. The approach introduced here is a simple, effective, scalable and reproducible way to fabricate TENGs.

  1. Surveys on specific patterns of facility intallation of photovoltaic power generating technologies for international cooperation

    NASA Astrophysics Data System (ADS)

    1993-03-01

    The objective is to contribute to the international introduction of photovoltaic power generation. To do this, its load patterns, device constitution, land areas, and prices were rearranged and standardized so that design standardization and efficiency improvement may be achieved, and appropriate introduction patterns may be selected from climatic conditions at various sites. Areas dealt with are Africa, Asia, Oceania, and South and Central America. The basic design consists of combination of solar cells with storage batteries for DC load, whereas inverters were added for AC load. Facility capacities were designed so that they can be calculated by assuming general load menus comprising lighting, pumps, and electric appliances, as well as load patterns. Because of non-electrified areas requiring insolation to take care of all of the annual load, minimum monthly average insolation on slopes was used to calculate solar cell capacities. While storage battery capacities will be established upon investigating climatic conditions at proposed sites, arrangements were made on selecting charge controllers that can avoid overcharging and overdischarging due to variation in insolation. A design procedure document was prepared so that the basic design could be carried out efficiently.

  2. Central pattern generators for social vocalization: Androgen-dependent neurophysiological mechanisms

    PubMed Central

    Bass, Andrew H.; Remage-Healey, Luke

    2008-01-01

    Historically, most studies of vertebrate central pattern generators (CPGs) have focused on mechanisms for locomotion and respiration. Here, we highlight new results for ectothermic vertebrates, namely teleost fish and amphibians, showing how androgenic steroids can influence the temporal patterning of CPGs for social vocalization. Investigations of vocalizing teleosts show how androgens can rapidly (within minutes) modulate the neurophysiological output of the vocal CPG (fictive vocalizations that mimic the temporal properties of natural vocalizations) inclusive of their divergent actions between species, as well as intraspecific differences between male reproductive morphs. Studies of anuran amphibians (frogs) demonstrate that long-term steroid treatments (wks) can masculinize the fictive vocalizations of females, inclusive of its sensitivity to rapid modulation by serotonin. Given the conserved organization of vocal control systems across vertebrate groups, the vocal CPGs of fish and amphibians provide tractable models for identifying androgen-dependent events that are fundamental to the mechanisms of vocal motor patterning. These basic mechanisms can also inform our understanding of the more complex CPGs for vocalization, and social behaviors in general, that have evolved among birds and mammals. PMID:18262186

  3. Atomic layer deposition on phase-shift lithography generated photoresist patterns for 1D nanochannel fabrication.

    PubMed

    Güder, Firat; Yang, Yang; Krüger, Michael; Stevens, Gregory B; Zacharias, Margit

    2010-12-01

    A versatile, low-cost, and flexible approach is presented for the fabrication of millimeter-long, sub-100 nm wide 1D nanochannels with tunable wall properties (wall thickness and material) over wafer-scale areas on glass, alumina, and silicon surfaces. This approach includes three fabrication steps. First, sub-100 nm photoresist line patterns were generated by near-field contact phase-shift lithography (NFC-PSL) using an inexpensive homemade borosilicate mask (NFC-PSM). Second, various metal oxides were directly coated on the resist patterns with low-temperature atomic layer deposition (ALD). Finally, the remaining photoresist was removed via an acetone dip, and then planar nanochannel arrays were formed on the substrate. In contrast to all the previous fabrication routes, the sub-100 nm photoresist line patterns produced by NFC-PSL are directly employed as a sacrificial layer for the creation of nanochannels. Because both the NFC-PSL and the ALD deposition are highly reproducible processes, the strategy proposed here can be regarded as a general route for nanochannel fabrication in a simplified and reliable manner. In addition, the fabricated nanochannels were used as templates to synthesize various organic and inorganic 1D nanostructures on the substrate surface. PMID:21047101

  4. Atomic layer deposition on phase-shift lithography generated photoresist patterns for 1D nanochannel fabrication.

    PubMed

    Güder, Firat; Yang, Yang; Krüger, Michael; Stevens, Gregory B; Zacharias, Margit

    2010-12-01

    A versatile, low-cost, and flexible approach is presented for the fabrication of millimeter-long, sub-100 nm wide 1D nanochannels with tunable wall properties (wall thickness and material) over wafer-scale areas on glass, alumina, and silicon surfaces. This approach includes three fabrication steps. First, sub-100 nm photoresist line patterns were generated by near-field contact phase-shift lithography (NFC-PSL) using an inexpensive homemade borosilicate mask (NFC-PSM). Second, various metal oxides were directly coated on the resist patterns with low-temperature atomic layer deposition (ALD). Finally, the remaining photoresist was removed via an acetone dip, and then planar nanochannel arrays were formed on the substrate. In contrast to all the previous fabrication routes, the sub-100 nm photoresist line patterns produced by NFC-PSL are directly employed as a sacrificial layer for the creation of nanochannels. Because both the NFC-PSL and the ALD deposition are highly reproducible processes, the strategy proposed here can be regarded as a general route for nanochannel fabrication in a simplified and reliable manner. In addition, the fabricated nanochannels were used as templates to synthesize various organic and inorganic 1D nanostructures on the substrate surface.

  5. Modeling the morphodynamic galectin patterning network of the developing avian limb skeleton.

    PubMed

    Glimm, T; Bhat, R; Newman, S A

    2014-04-01

    We present a mathematical model for the morphogenesis and patterning of the mesenchymal condensations that serve as primordia of the avian limb skeleton. The model is based on the experimentally established dynamics of a multiscale regulatory network consisting of two glycan-binding proteins expressed early in limb development: CG (chicken galectin)-1A, CG-8 and their counterreceptors that determine the formation, size, number and spacing of the "protocondensations" that give rise to the condensations and subsequently the cartilaginous elements that serve as the templates of the bones. The model, a system of partial differential and integro-differential equations containing a flux term to represent local adhesion gradients, is simulated in a "full" and a "reduced" form to confirm that the system has pattern-forming capabilities and to explore the nature of the patterning instability. The full model recapitulates qualitatively and quantitatively the experimental results of network perturbation and leads to new predictions, which are verified by further experimentation. The reduced model is used to demonstrate that the patterning process is inherently morphodynamic, with cell motility being intrinsic to it. Furthermore, subtle relationships between cell movement and the positive and negative interactions between the morphogens produce regular patterns without the requirement for activators and inhibitors with widely separated diffusion coefficients. The described mechanism thus represents an extension of the category of activator-inhibitor processes capable of generating biological patterns with repetitive elements beyond the morphostatic mechanisms of the Turing/Gierer-Meinhardt type. PMID:24355216

  6. Electrochemical machining development for turbine generator rotor slots. Final report

    SciTech Connect

    Not Available

    1984-03-01

    The Electrochemical Machining Development for Turbine Generator Rotor Slots was initiated to provide a viable alternative to conventional machining of slots in conventional rotor forging materials and in advanced metallurgical alloys. ECM was selected because it is a stress-free machining process and is insensitive to material hardness. ECM concepts were developed and reviewed with ECM consultants prior to development work.

  7. Natural gas development and utilisation pattern in India

    SciTech Connect

    Mulchandani, H.K.; Balakrishnan, M.

    1984-02-01

    In this era of energy consciousness, Natural Gas is destined to play an important role in the economic life of India. The luxury of flaring into atmosphere is over. Rather stocks are being assessed and capital investments are planned for the optimum development and utilisation of gas. In this paper, authors have attempted to tie up various data on different aspects of gas business such as supply, source, production, utilisation pattern and its share in energy and economy. The optimal utilisation plan as discussed here could be of some value to the planners.

  8. Extreme ultraviolet patterned mask inspection performance of advanced projection electron microscope system for 11nm half-pitch generation

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    Novel projection electron microscope optics have been developed and integrated into a new inspection system named EBEYE-V30 ("Model EBEYE" is an EBARA's model code) , and the resulting system shows promise for application to half-pitch (hp) 16-nm node extreme ultraviolet lithography (EUVL) patterned mask inspection. To improve the system's inspection throughput for 11-nm hp generation defect detection, a new electron-sensitive area image sensor with a high-speed data processing unit, a bright and stable electron source, and an image capture area deflector that operates simultaneously with the mask scanning motion have been developed. A learning system has been used for the mask inspection tool to meet the requirements of hp 11-nm node EUV patterned mask inspection. Defects are identified by the projection electron microscope system using the "defectivity" from the characteristics of the acquired image. The learning system has been developed to reduce the labor and costs associated with adjustment of the detection capability to cope with newly-defined mask defects. We describe the integration of the developed elements into the inspection tool and the verification of the designed specification. We have also verified the effectiveness of the learning system, which shows enhanced detection capability for the hp 11-nm node.

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

    PubMed

    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.

  10. Directivity patterns of ultrasonic waves generated by a laser pulse at the interface between two elastic media

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, E.; Ségur, D.; Dehoux, T.; Audoin, B.

    2016-02-01

    Directivity patterns of an acoustic source generated by the absorption of a laser pulse at the interface between a transparent epoxy-resin half-space and an opaque CFRP isotropised half-space have been calculated using the reciprocity theorem. Longitudinal and shear radiation patterns of acoustic field emitted in the CFRP are compared in respect with the loading surface condition.

  11. Expression Pattern of Axin2 During Chicken Development

    PubMed Central

    Eckei, Gesa; Böing, Marion; Brand-Saberi, Beate; Morosan-Puopolo, Gabriela

    2016-01-01

    Canonical Wnt-signalling is well understood and has been extensively described in many developmental processes. The regulation of this signalling pathway is of outstanding relevance for proper development of the vertebrate and invertebrate embryo. Axin2 provides a negative-feedback-loop in the canonical Wnt-pathway, being a target gene and a negative regulator. Here we provide a detailed analysis of the expression pattern in the development of the chicken embryo. By performing in-situ hybridization on chicken embryos from stage HH 04+ to HH 32 we detected a temporally and spatially restricted dynamic expression of Axin2. In particular, data about the expression of Axin2 mRNA in early embryogenesis, somites, neural tube, limbs, kidney and eyes was obtained. PMID:27680024

  12. Characterization of a non-chemically amplified resist for photomask fabrication using a 257-nm optical pattern generator

    NASA Astrophysics Data System (ADS)

    Rathsack, Benjamen M.; Tabery, Cyrus E.; Stachowiak, Timothy B.; Dallas, Tim E.; Xu, Cheng-Bai; Pochkowski, Mike; Willson, C. Grant

    1999-12-01

    I-line optical pattern generators using non-chemically amplified resists have become the workhorses for high throughput mask fabrication. The demand for smaller and more uniform features on photomasks has driven the development of a 257 nm optical pattern generator. A non-chemically amplified resist is being developed to maximize the performance of this new 257 nm mask tool. Resist characterization and lithography simulation are being used to formulate a non-chemically amplified resist for 257 nm optical pattern generators. Non- chemically amplified resists are advantageous for us in mask fabrication due to their storage and post-exposure stability. Chemically amplified resists may provide higher performance but they also require environmental mini-environments and a post-exposure bake equipment not commonly present in mask houses. Diazonaphthoquinone (DNQ)/novolak resists have not been used for DUV Integrated Circuit (IC) applications mainly due to the low sensitivity and the strong absorbance of the DNQ photoactive compound (PAC) at 248 nm. However, a 2,1,4 DNQ based resist has been characterized that bleaches at 257 nm and inhibits novolak. The photoproduct of the 2,1,4 DNQ PAC is much more transparent at 257 nm than 248 nm. Novolak resin is too strongly absorbing for use in formulating efficient 248 nm resists, but novolak has an absorbance minimum at 257 nm that provides transparency similar to poly (hydroxystyrene). Lithography simulation is being used to develop a non- chemically amplified resist to minimize the expensive iteration of manufacturing trials. An exposure system using a 257 nm frequency double Ar laser system has been constructed to study the resist photokinetics. Dill exposure parameters (A, B and C) have been extracted for a 2,1,4 DNQ/novolak based resist. Dissolution rate measurements have been made with a DRM developed at the University of Texas at Austin. Simulation is used to determine the optimal resist absorption, bleaching, dose and

  13. Bio-inspired patterned networks (BIPS) for development of wearable/disposable biosensors

    NASA Astrophysics Data System (ADS)

    McLamore, E. S.; Convertino, M.; Hondred, John; Das, Suprem; Claussen, J. C.; Vanegas, D. C.; Gomes, C.

    2016-05-01

    Here we demonstrate a novel approach for fabricating point of care (POC) wearable electrochemical biosensors based on 3D patterning of bionanocomposite networks. To create Bio-Inspired Patterned network (BIPS) electrodes, we first generate fractal network in silico models that optimize transport of network fluxes according to an energy function. Network patterns are then inkjet printed onto flexible substrate using conductive graphene ink. We then deposit fractal nanometal structures onto the graphene to create a 3D nanocomposite network. Finally, we biofunctionalize the surface with biorecognition agents using covalent bonding. In this paper, BIPS are used to develop high efficiency, low cost biosensors for measuring glucose as a proof of concept. Our results on the fundamental performance of BIPS sensors show that the biomimetic nanostructures significantly enhance biosensor sensitivity, accuracy, response time, limit of detection, and hysteresis compared to conventional POC non fractal electrodes (serpentine, interdigitated, and screen printed electrodes). BIPs, in particular Apollonian patterned BIPS, represent a new generation of POC biosensors based on nanoscale and microscale fractal networks that significantly improve electrical connectivity, leading to enhanced sensor performance.

  14. Evolutionary aspects of pattern formation during clitellate muscle development.

    PubMed

    Bergter, Annette; Hunnekuhl, Vera S; Schniederjans, Monika; Paululat, Achim

    2007-01-01

    As a taxon of the lophotrochozoans, annelids have re-entered scientific investigations focusing on plesiomorphic bilaterian features and the evolutionary changes therein. The view of a clitellate-like plesiomorphic muscle arrangement in annelids has been challenged by recent investigations of polychaete muscle organization. However, there are few investigations of muscle formation in clitellate species that address this problem. Direct comparison of potential homologous muscles between these annelid groups is thus hampered. Somatic muscle formation during embryogenesis of two clitellates-the oligochaete Limnodrilus sp. and the hirudinean Erpobdella octoculata-occurs by distinct processes in each species, even though they share a closed outer layer of circular and an inner layer of longitudinal muscles characteristic of clitellates. In E. octoculata, the first emerging longitudinal muscles are distributed irregularly on the body surface of the embryo whereas the circular muscles appear in an orderly repetitive pattern along the anterioposterior axis. Both primary muscle types consist of fiber-bundles that branch at both their ends. This way the circular muscle bundles divide into a fine muscle-grid. The primary longitudinal muscles are incorporated into a second type of longitudinal muscles, the latter starting to differentiate adjacent to the ventral nerve cord. Those secondary muscles emerge in a ventral to dorsal manner, enclosing the embryo of E. octoculata. In Limnodrilus sp., one dorsal and one ventral bilateral pair of primary longitudinal muscles are established initially, elongating toward posterior. Initial circular muscles are emerging in a segmental pattern. Both muscle layers are completed later in development by the addition of secondary longitudinal and circular muscles. Some features of embryonic longitudinal muscle patterns in Limnodrilus sp. are comparable to structures found in adult polychaete muscle systems. Our findings show that comparative

  15. Developing Assessments for the Next Generation Science Standards

    ERIC Educational Resources Information Center

    Pellegrino, James W., Ed.; Wilson, Mark R., Ed.; Koenig, Judith A., Ed.; Beatty, Alexandra S., Ed.

    2014-01-01

    Assessments, understood as tools for tracking what and how well students have learned, play a critical role in the classroom. "Developing Assessments for the Next Generation Science Standards" develops an approach to science assessment to meet the vision of science education for the future as it has been elaborated in "A Framework…

  16. Generating realistic environments for cyber operations development, testing, and training

    NASA Astrophysics Data System (ADS)

    Berk, Vincent H.; Gregorio-de Souza, Ian; Murphy, John P.

    2012-06-01

    Training eective cyber operatives requires realistic network environments that incorporate the structural and social complexities representative of the real world. Network trac generators facilitate repeatable experiments for the development, training and testing of cyber operations. However, current network trac generators, ranging from simple load testers to complex frameworks, fail to capture the realism inherent in actual environments. In order to improve the realism of network trac generated by these systems, it is necessary to quantitatively measure the level of realism in generated trac with respect to the environment being mimicked. We categorize realism measures into statistical, content, and behavioral measurements, and propose various metrics that can be applied at each level to indicate how eectively the generated trac mimics the real world.

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

    PubMed

    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.

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

    PubMed Central

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

    2013-01-01

    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. PMID:24303193

  19. 2nd Generation Reusable Launch Vehicle Potential Commercial Development Scenarios

    NASA Technical Reports Server (NTRS)

    Creech, Stephen D.; Rogacki, John R. (Technical Monitor)

    2001-01-01

    The presentation will discuss potential commercial development scenarios for a Second Generation Reusable Launch Vehicle. The analysis of potential scenarios will include commercial rates of return, government return on investment, and market considerations. The presentation will include policy considerations in addition to analysis of Second Generation Reusable Launch Vehicle economics. The data discussed is being developed as a part of NASA's Second Generation Reusable Launch Vehicle Program, for consideration as potential scenarios for enabling a next generation system. Material will include potential scenarios not previously considered by NASA or presented at other conferences. Candidate paper has not been presented at a previous meeting, and conference attendance of the author has been approved by NASA.

  20. Muscle activity pattern dependent pain development and alleviation.

    PubMed

    Sjøgaard, Gisela; Søgaard, Karen

    2014-12-01

    Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms of muscle pain. Focusing on muscle activity patterns and musculoskeletal health it is pertinent to elucidate the more specific aspects regarding exposure profiles and body regional pain. Static sustained muscle contraction for prolonged periods often occurs in the neck/shoulder area during occupational tasks and may underlie muscle pain development in spite of rather low relative muscle load. Causal mechanisms include a stereotype recruitment of low threshold motor units (activating type 1 muscle fibers) characterized by a lack of temporal as well as spatial variation in recruitment. In contrast during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain development if adequate recovery is granted. However, delayed muscle soreness may develop following intensive eccentric muscle activity (e.g. down-hill skiing) with peak pain levels in thigh muscles 1-2 days after the exercise bout and a total recovery within 1 week. This acute pain profile is in contrast to the chronic muscle pain profile related to repetitive monotonous work tasks. The painful muscles show adverse functional, morphological, hormonal, as well as metabolic characteristics. Of

  1. Dynamic control of a central pattern generator circuit: a computational model of the snail feeding network.

    PubMed

    Vavoulis, Dimitris V; Straub, Volko A; Kemenes, Ildikó; Kemenes, György; Feng, Jianfeng; Benjamin, Paul R

    2007-05-01

    Central pattern generators (CPGs) are networks underlying rhythmic motor behaviours and they are dynamically regulated by neuronal elements that are extrinsic or intrinsic to the rhythmogenic circuit. In the feeding system of the pond snail, Lymnaea stagnalis, the extrinsic slow oscillator (SO) interneuron controls the frequency of the feeding rhythm and the N3t (tonic) has a dual role; it is an intrinsic CPG interneuron, but it also suppresses CPG activity in the absence of food, acting as a decision-making element in the feeding circuit. The firing patterns of the SO and N3t neurons and their synaptic connections with the rest of the CPG are known, but how these regulate network function is not well understood. This was investigated by building a computer model of the feeding network based on a minimum number of cells (N1M, N2v and N3t) required to generate the three-phase motor rhythm together with the SO that was used to activate the system. The intrinsic properties of individual neurons were represented using two-compartment models containing currents of the Hodgkin-Huxley type. Manipulations of neuronal activity in the N3t and SO neurons in the model produced similar quantitative effects to food and electrical stimulation in the biological network indicating that the model is a useful tool for studying the dynamic properties of the feeding circuit. The model also predicted novel effects of electrical stimulation of two CPG interneurons (N1M and N2v). When tested experimentally, similar effects were found in the biological system providing further validation of our model.

  2. Correlation of hierarchal Upper Silurian stacking patterns generated by Milankovitch orbital forcing

    SciTech Connect

    Mauriello, D.J.; Ketterer, M.W. . Dept. of Geology)

    1993-03-01

    The Upper Silurian Wills Creek Formation in Pennsylvania and Maryland is entirely divisible into meter-scale allocycles. Stacking patterns of these allocycles reveal a hierarchy consistent with predictions based on the Milankovitch model of orbital forcing. Asymmetrical Sixth-Order cycles (PACs), bounded by surfaces produced by precessional sea-level rises, are divisible into a lower highstand portion and an upper lowstand portion separated by a sharp sea-level fall surface produced by a rapid sea-level drop within the precessional cycle. Sixth-Order cycles may be genetically grouped into Fifth-Order (100 ky.) and subsequently, Fourth-Order (400 ky.) cycles, each of which exhibits a distinct internal symmetry. Fifth-Order cycles, on average three to four meters in thickness, are composed of a basal transgressive portion consisting of two PACs followed by two or three successively regressive PACs. Four Fifth-Order cycles constitute a complete Fourth-Order cycle, in which the second Fifth-Order cycle contains facies representing the deepest or least restricted paleoenvironments. In each case, the fundamental Sixth-Order cycles were generated by the precessional signal modulated by orbital eccentricity variations. Over distances in excess of 100 km, Wills Creek facies change laterally from nearshore marine to fluvial coastal plain. Stacking patterns in these distinct facies are identical, and thus correlative, indicating the basin-wide extent of the stratigraphic events which produced these patterns. These correlations demonstrate that Milankovitch-driven eustatic sea-level fluctuations were occurring during the Late Silurian.

  3. Diversity of wing patterns and abdomen-generated substrate sounds in 3 European scorpionfly species

    PubMed Central

    Hartbauer, Manfred; Gepp, Johannes; Hinteregger, Karin; Koblmüller, Stephan

    2016-01-01

    In the genus Panorpa (Insecta: Mecoptera), also known as scorpionflies, premating behavior includes repeated sequences of slow wing movements (waving, fanning, flagging) which are accompanied by rapid abdomen vibrations that generate substantial substrate-borne sound. It is still unknown whether wing patterns or vibratory signals contain information about species identity, sex and/or the quality of potential mating partners. Besides species-specific pheromones, these multimodal signals may be of particular importance for the maintenance of reproductive isolation in sympatrically occurring scorpionfly species. Here, we analyzed phyologenetic relationships among, and the pattern of forewings as well as substrate-borne sound in 3 different sympatric Central-European scorpionfly species (P. communis, P. germanica, and P. alpina). Divergence time estimates, based on 879 bp of the mitochondrial COI gene, indicate longstanding separate evolutionary histories for the studied Panorpa species. Morphological analysis revealed that wing length as an indicator of body size increased in the following order: P. alpina < P. germanica < P. communis. Individuals can be assigned to the correct species and sex with high accuracy just by evaluation of the number of dark spots and the proportion of wing pigmentation. Despite high variability of interpulse period at an individual level, across species analysis revealed a positive correlation of average interpulse period as well as mean signal amplitude with forewing length. These results suggest wing patterns, but less likely vibratory signals, to contain information about species identity. Furthermore, receivers may be able to estimate the body size of a signaler solely on the basis of substrate-borne sound. PMID:24818592

  4. Homologues of serotonergic central pattern generator neurons in related nudibranch molluscs with divergent behaviors.

    PubMed

    Newcomb, James M; Katz, Paul S

    2007-04-01

    Homologues of a neuron that contributes to a species-specific behavior were identified and characterized in species lacking that behavior. The nudibranch Tritonia diomedea swims by flexing its body dorsally and ventrally. The dorsal swim interneurons (DSIs) are components of the central pattern generator (CPG) underlying this rhythmic motor pattern and also activate crawling. Homologues of the DSIs were identified in six nudibranchs that do not exhibit dorsal-ventral swimming: Tochuina tetraquetra, Melibe leonina, Dendronotus iris, D. frondosus, Armina californica, and Triopha catalinae. Homology was based upon shared features that distinguish the DSIs from all other neurons: (1) serotonin immunoreactivity, (2) location in the Cerebral serotonergic posterior (CeSP) cluster, and (3) axon projection to the contralateral pedal ganglion. The DSI homologues, named CeSP-A neurons, share additional features with the DSIs: irregular basal firing, synchronous inputs, electrical coupling, and reciprocal inhibition. Unlike the DSIs, the CeSP-A neurons were not rhythmically active in response to nerve stimulation. The CeSP-A neurons in Tochuina and Triopha also excited homologues of the Tritonia Pd5 neuron, a crawling efferent. Thus, the CeSP-A neurons and the DSIs may be part of a conserved network related to crawling that may have been co-opted into a rhythmic swim CPG in Tritonia. PMID:17180703

  5. Directed functional connectivity matures with motor learning in a cortical pattern generator

    PubMed Central

    Day, Nancy F.; Terleski, Kyle L.; Nykamp, Duane Q.

    2013-01-01

    Sequential motor skills may be encoded by feedforward networks that consist of groups of neurons that fire in sequence (Abeles 1991; Long et al. 2010). However, there has been no evidence of an anatomic map of activation sequence in motor control circuits, which would be potentially detectable as directed functional connectivity of coactive neuron groups. The proposed pattern generator for birdsong, the HVC (Long and Fee 2008; Vu et al. 1994), contains axons that are preferentially oriented in the rostrocaudal axis (Nottebohm et al. 1982; Stauffer et al. 2012). We used four-tetrode recordings to assess the activity of ensembles of single neurons along the rostrocaudal HVC axis in anesthetized zebra finches. We found an axial, polarized neural network in which sequential activity is directionally organized along the rostrocaudal axis in adult males, who produce a stereotyped song. Principal neurons fired in rostrocaudal order and with interneurons that were rostral to them, suggesting that groups of excitatory neurons fire at the leading edge of travelling waves of inhibition. Consistent with the synchronization of neurons by caudally travelling waves of inhibition, the activity of interneurons was more coherent in the orthogonal mediolateral axis than in the rostrocaudal axis. If directed functional connectivity within the HVC is important for stereotyped, learned song, then it may be lacking in juveniles, which sing a highly variable song. Indeed, we found little evidence for network directionality in juveniles. These data indicate that a functionally directed network within the HVC matures during sensorimotor learning and may underlie vocal patterning. PMID:23175804

  6. Spatial and temporal gene expression patterns occur during corm development.

    PubMed

    de Castro, L A; Carneiro, M; Neshich, D de C; de Paiva, G R

    1992-12-01

    We investigated gene expression patterns that occur during taro corm development. Two-dimensional gel electrophoresis identified several different prevalent proteins that accumulate during corm development. Microsequencing studies indicated that some of these proteins are related to taste-modifying proteins, such as curculin and miraculin, and proteins found in other storage organs, such as sporamin and the Kunitz trypsin inhibitor. A curculin-encoding cDNA clone, designated as TC1, was identified that corresponds to a highly prevalent 1-kb corm mRNA. The TC1 mRNA accumulates during corm development, is more prevalent in corm apical than basal regions, and is either absent, or present at low concentrations, in other vegetative organs such as the leaf and root. In situ hybridization experiments showed that the TC1 mRNA is highly concentrated in corm storage parenchyma cells and is absent, or present in reduced concentrations, in other corm cells and tissues. Our results show that corm development is associated with the differentiation of specialized cells and tissues, and that these differentiation events are coupled with the temporal and spatial expression of corm-specific genes. PMID:1467653

  7. Developing common learning: the new generation project undergraduate curriculum model.

    PubMed

    O'Halloran, C; Hean, S; Humphris, D; Macleod-Clark, J

    2006-01-01

    This paper describes the curriculum model developed for an ambitious interprofessional education programme for health and social care professions implemented in two universities in the south of England (the New Generation Project). An outline of how the New Generation Project has interpreted the meaning of interprofessional learning is presented first. This is followed by an outline of the structure of the programme, describing both learning in common and interprofessional learning components. The pedagogies underpinning this curriculum initiative are presented and an integrated pedagogical model, facilitated collaborative interprofessional learning, is proposed. The New Generation Project curriculum is then discussed as an extension of an established typology of interprofessional education. PMID:16581636

  8. Evolution-development congruence in pattern formation dynamics: Bifurcations in gene expression and regulation of networks structures.

    PubMed

    Kohsokabe, Takahiro; Kaneko, Kunihiko

    2016-01-01

    Search for possible relationships between phylogeny and ontogeny is important in evolutionary-developmental biology. Here we uncover such relationships by numerical evolution and unveil their origin in terms of dynamical systems theory. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell-to-cell interaction under external morphogen gradient, gene regulation networks are evolved under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Both in the evolution and development pattern changes consist of several epochs where stripes are formed in a short time, while for other temporal regimes, pattern hardly changes. In evolution, these quasi-stationary regimes are generations needed to hit relevant mutations, while in development, they are due to some gene expression that varies slowly and controls the pattern change. The morphogenesis is regulated by combinations of feedback or feedforward regulations, where the upstream feedforward network reads the external morphogen gradient, and generates a pattern used as a boundary condition for the later patterns. The ordering from up to downstream is common in evolution and development, while the successive epochal changes in development and evolution are represented as common bifurcations in dynamical-systems theory, which lead to the evolution-development congruence. Mechanism of exceptional violation of the congruence is also unveiled. Our results provide a new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis.

  9. Evolution‐development congruence in pattern formation dynamics: Bifurcations in gene expression and regulation of networks structures

    PubMed Central

    Kohsokabe, Takahiro

    2016-01-01

    ABSTRACT Search for possible relationships between phylogeny and ontogeny is important in evolutionary‐developmental biology. Here we uncover such relationships by numerical evolution and unveil their origin in terms of dynamical systems theory. By representing developmental dynamics of spatially located cells with gene expression dynamics with cell‐to‐cell interaction under external morphogen gradient, gene regulation networks are evolved under mutation and selection with the fitness to approach a prescribed spatial pattern of expressed genes. For most numerical evolution experiments, evolution of pattern over generations and development of pattern by an evolved network exhibit remarkable congruence. Both in the evolution and development pattern changes consist of several epochs where stripes are formed in a short time, while for other temporal regimes, pattern hardly changes. In evolution, these quasi‐stationary regimes are generations needed to hit relevant mutations, while in development, they are due to some gene expression that varies slowly and controls the pattern change. The morphogenesis is regulated by combinations of feedback or feedforward regulations, where the upstream feedforward network reads the external morphogen gradient, and generates a pattern used as a boundary condition for the later patterns. The ordering from up to downstream is common in evolution and development, while the successive epochal changes in development and evolution are represented as common bifurcations in dynamical‐systems theory, which lead to the evolution‐development congruence. Mechanism of exceptional violation of the congruence is also unveiled. Our results provide a new look on developmental stages, punctuated equilibrium, developmental bottlenecks, and evolutionary acquisition of novelty in morphogenesis. J. Exp. Zool. (Mol. Dev. Evol.) 326B:61–84, 2016. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution

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

    NASA Astrophysics Data System (ADS)

    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.

  11. The Graphic Pattern Generation Test in Healthy Aging and Alzheimer's Disease: Psychometric Properties and Normative Data

    PubMed Central

    Sunderaraman, Preeti; Sokolov, Elisaveta; Cines, Sarah; Sullo, Elizabeth; Orly, Aidan; Lerer, Bianca; Karlawish, Jason; Huey, Edward; Cosentino, Stephanie

    2015-01-01

    Design fluency tests, commonly used in both clinical and research contexts to evaluate nonverbal concept generation, have the potential to offer useful information in the differentiation of healthy versus pathological aging. While normative data for older adults are available for multiple timed versions of this test, similar data have been unavailable for a previously published untimed task, the Graphic Pattern Generation Task (GPG). Time constraints common to almost all of the available design fluency tests may cloud interpretation of higher level executive abilities, for example in individuals with slow processing speed. The current study examined the psychometric properties of the GPG and presents normative data in a sample of 167 healthy older adults (OAs) and 110 individuals diagnosed with Alzheimer's disease (AD). Results suggest that a brief version of the GPG can be administered reliably, and that this short form has high test-retest and inter-rater reliability. Number of perseverations was higher in individuals with AD as compared to OAs. A cut-off score of 4 or more perseverations showed a moderate degree of sensitivity (76%) and specificity (37%) in distinguishing individuals with AD and OAs. Finally, perseverations were associated with nonmemory indices, underscoring the nonverbal nature of this error in OAs and individuals with AD. PMID:25679880

  12. Development of large wind energy power generation system

    NASA Astrophysics Data System (ADS)

    1983-11-01

    The background and development of an experimental 100 kW wind-energy generation system are described, and the results of current field tests are presented. The experimental wind turbine is a two-bladed down-wind horizontal axis propeller type with a 29.4 m diameter rotor and a tower 28 m in height. The plant was completed in March 1983 and has been undergoing trouble-free tests since then. The present program calls for field tests during two years from fiscal 1983 to 1984. The development of technologies relating to the linkage and operation of wind-energy power generation system networks is planned along with the acquisition of basic data for the development of a large-scale wind energy power generation system.

  13. Development of large wind energy power generation system

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The background and development of an experimental 100 kW wind-energy generation system are described, and the results of current field tests are presented. The experimental wind turbine is a two-bladed down-wind horizontal axis propeller type with a 29.4 m diameter rotor and a tower 28 m in height. The plant was completed in March, 1983, and has been undergoing trouble-free tests since then. The present program calls for field tests during two years from fiscal 1983 to 1984. The development of technologies relating to the linkage and operation of wind-energy power generation system networks is planned along with the acquisition of basic data for the development of a large-scale wind energy power generation system.

  14. Tooth development in a model reptile: functional and null generation teeth in the gecko Paroedura picta.

    PubMed

    Zahradnicek, Oldrich; Horacek, Ivan; Tucker, Abigail S

    2012-09-01

    This paper describes tooth development in a basal squamate, Paroedura picta. Due to its reproductive strategy, mode of development and position within the reptiles, this gecko represents an excellent model organism for the study of reptile development. Here we document the dental pattern and development of non-functional (null generation) and functional generations of teeth during embryonic development. Tooth development is followed from initiation to cytodifferentiation and ankylosis, as the tooth germs develop from bud, through cap to bell stages. The fate of the single generation of non-functional (null generation) teeth is shown to be variable, with some teeth being expelled from the oral cavity, while others are incorporated into the functional bone and teeth, or are absorbed. Fate appears to depend on the initiation site within the oral cavity, with the first null generation teeth forming before formation of the dental lamina. We show evidence for a stratum intermedium layer in the enamel epithelium of functional teeth and show that the bicuspid shape of the teeth is created by asymmetrical deposition of enamel, and not by folding of the inner dental epithelium as observed in mammals.

  15. A general-purpose computer program for studying ultrasonic beam patterns generated with acoustic lenses

    NASA Technical Reports Server (NTRS)

    Roberti, Dino; Ludwig, Reinhold; Looft, Fred J.

    1988-01-01

    A 3-D computer model of a piston radiator with lenses for focusing and defocusing is presented. To achieve high-resolution imaging, the frequency of the transmitted and received ultrasound must be as high as 10 MHz. Current ultrasonic transducers produce an extremely narrow beam at these high frequencies and thus are not appropriate for imaging schemes such as synthetic-aperture focus techniques (SAFT). Consequently, a numerical analysis program has been developed to determine field intensity patterns that are radiated from ultrasonic transducers with lenses. Lens shapes are described and the field intensities are numerically predicted and compared with experimental results.

  16. Modeling parr-mark pattern formation during the early development of Amago trout

    NASA Astrophysics Data System (ADS)

    Venkataraman, Chandrasekhar; Sekimura, Toshio; Gaffney, Eamonn A.; Maini, Philip K.; Madzvamuse, Anotida

    2011-10-01

    This paper studies the formation of the large dark patterns, known as parr marks, that form on the Amago trout as it grows from the early larval stages to adulthood. The Amago trout, known as Oncorhynchus masou ishikawa, exhibits stripes during the early stages of development that in turn evolve (through reorientation and peak insertion) to form zigzag spot patterns as the fish grows to adulthood. By considering a standard representation of the Turing model for biological self-organization via interacting and diffusing morphogens, we illustrate that a diffusively driven instability can generate transient patterns consistent with those experimentally observed during the process of parr-mark formation in the early development of the Amago trout. Surface evolution is modeled through an experimentally driven growth function. Our studies conclude that the surface evolution profile, the surface geometry, and the curvature are key factors that play a pivotal role in reaction-diffusion systems in a study motivated by observations of Amago trout parr-mark pattern formation.

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

    PubMed

    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).

  18. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching.

    PubMed

    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.

  19. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching.

    PubMed

    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

  20. Next generation sequencing (NGS) database for tandem repeats with multiple pattern 2°-shaft multicore string matching

    PubMed Central

    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

  1. IVHM for the 3rd Generation RLV Program: Technology Development

    NASA Technical Reports Server (NTRS)

    Kahle, Bill

    2000-01-01

    The objective behind the Integrated Vehicle Health Management (IVHM) project is to develop and integrate the technologies which can provide a continuous, intelligent, and adaptive health state of a vehicle and use this information to improve safety and reduce costs of operations. Technological areas discussed include: developing, validating, and transfering next generation IVHM technologies to near term industry and government reusable launch systems; focus NASA on the next generation and highly advanced sensor and software technologies; and validating IVHM systems engineering design process for future programs.

  2. Graphical User Interface Development for Representing Air Flow Patterns

    NASA Technical Reports Server (NTRS)

    Chaudhary, Nilika

    2004-01-01

    In the Turbine Branch, scientists carry out experimental and computational work to advance the efficiency and diminish the noise production of jet engine turbines. One way to do this is by decreasing the heat that the turbine blades receive. Most of the experimental work is carried out by taking a single turbine blade and analyzing the air flow patterns around it, because this data indicates the sections of the turbine blade that are getting too hot. Since the cost of doing turbine blade air flow experiments is very high, researchers try to do computational work that fits the experimental data. The goal of computational fluid dynamics is for scientists to find a numerical way to predict the complex flow patterns around different turbine blades without physically having to perform tests or costly experiments. When visualizing flow patterns, scientists need a way to represent the flow conditions around a turbine blade. A researcher will assign specific zones that surround the turbine blade. In a two-dimensional view, the zones are usually quadrilaterals. The next step is to assign boundary conditions which define how the flow enters or exits one side of a zone. way of setting up computational zones and grids, visualizing flow patterns, and storing all the flow conditions in a file on the computer for future computation. Such a program is necessary because the only method for creating flow pattern graphs is by hand, which is tedious and time-consuming. By using a computer program to create the zones and grids, the graph would be faster to make and easier to edit. Basically, the user would run a program that is an editable graph. The user could click and drag with the mouse to form various zones and grids, then edit the locations of these grids, add flow and boundary conditions, and finally save the graph for future use and analysis. My goal this summer is to create a graphical user interface (GUI) that incorporates all of these elements. I am writing the program in

  3. Flow development and analysis of MHD generators and seawater thrusters

    SciTech Connect

    Doss, E.D. ); Roy, G.D. )

    1992-03-01

    In this paper, the flow characteristics inside magnetohydrodynamic (MHD) plasma generators and seawater thrusters are analyzed and are compared using a three-dimensional computer model that solves the governing partial differential equations for fluid flow and electrical fields. Calculations have been performed for a Faraday plasma generator and for a continuous electrode seawater thruster. The results of the calculations show that the effects caused by the interaction of the MHD forces with the fluid flow are strongly manifested in the case of the MHD generator as compared to the flow development in the MHD thruster. The existence of velocity overshoots over the sidewalls confirm previously published results for MHD generators with strong MHD interaction. For MHD thrusters, the velocity profile is found to be slightly flatter over the sidewall as compared to that over the electrode wall. As a result, distinct enhancement of the skin friction exists over the sidewalls of MHD generators in comparison to that of MHD thrusters. Plots of velocity profiles and skin friction distributions are presented to illustrate and compare the flow development in MHD generators and thrusters.

  4. Expression pattern of Sox2 during mouse tooth development.

    PubMed

    Zhang, Li; Yuan, Guohua; Liu, Huan; Lin, Heng; Wan, Chunyan; Chen, Zhi

    2012-01-01

    The transcription factor Sox2 plays important roles in maintaining the pluripotency of embryonic stem cells and adult progenitors. However, whether Sox2 is involved in odontogenesis has not been reported. In this study, we examined the expression pattern of Sox2 during mouse incisor and molar development using real-time PCR, in situ hybridization and immunohistochemistry. Sox2 mRNA was expressed in the dental epithelium and mesenchyme while Sox2 protein was mainly detected in the epithelium from embryonic day (E) 11.5 to postnatal (PN) day 20. In the case of incisor, Sox2 mRNA and protein were expressed in most of dental epithelial cells from E11.5 to E14.5, and they were both highly expressed in the labial cervical loop area from E16.5 to PN20. During molar development, we observed an asymmetrical distribution of Sox2 protein in the epithelium from E13.5 to E16.5, with stronger signals in the lingual side. From E18.5 to PN2, Sox2 was expressed within the cervical loop area, and the stellate intermediate layer. From PN6 to PN14, Sox2 expression was confined mainly to the apical end of hertwig's epithelium root sheath (HERS) cells. Sox2 was also detected within the perivascular region of the dental pulp at PN14 and PN20. Our results suggested that: (1) Sox2 was involved in mouse odontogenesis, and (2) it might participate in maintaining the pluripotency of the epithelial stem cells of labial cervical loop in mouse incisor development and the epithelium progenitors during molar development, (3) Sox2 might be regulated at post-transcription level during mouse odontogenesis.

  5. Development and Interaction of Artificially Generated Hairpin Vortices

    NASA Astrophysics Data System (ADS)

    Sabatino, Daniel; McKenna, Christopher

    2012-11-01

    The development and interaction of hairpin vortices are examined and categorized to better understand their role in fully turbulent boundary layers. Hairpin vortices are generated within an otherwise laminar boundary layer using a free surface water channel. Direct injection is the primary generation method and the behavior of the vortices is first examined using flow visualization. Hydrogen bubble wire is combined with dye injection to help clarify the role of the vorticity in the fluid immediately surrounding the hairpin vortex. PIV data is also used to classify the development and maturity of the vortices for a range of free stream and injection conditions. The interactions of two hairpin vortices of varying maturity are characterized to investigate the potential mechanisms for the formation of hairpin packets beyond autogeneration. Finally, the behavior of hairpin vortices generated with a new technique that uses a transient hemispherical protrusion is also examined. Supported by the National Science Foundation under Grant CBET-1040236.

  6. Patterned Anchorage to the Apical Extracellular Matrix Defines Tissue Shape in the Developing Appendages of Drosophila.

    PubMed

    Ray, Robert P; Matamoro-Vidal, Alexis; Ribeiro, Paulo S; Tapon, Nic; Houle, David; Salazar-Ciudad, Isaac; Thompson, Barry J

    2015-08-10

    How tissues acquire their characteristic shape is a fundamental unresolved question in biology. While genes have been characterized that control local mechanical forces to elongate epithelial tissues, genes controlling global forces in epithelia have yet to be identified. Here, we describe a genetic pathway that shapes appendages in Drosophila by defining the pattern of global tensile forces in the tissue. In the appendages, shape arises from tension generated by cell constriction and localized anchorage of the epithelium to the cuticle via the apical extracellular-matrix protein Dumpy (Dp). Altering Dp expression in the developing wing results in predictable changes in wing shape that can be simulated by a computational model that incorporates only tissue contraction and localized anchorage. Three other wing shape genes, narrow, tapered, and lanceolate, encode components of a pathway that modulates Dp distribution in the wing to refine the global force pattern and thus wing shape.

  7. Patterned Anchorage to the Apical Extracellular Matrix Defines Tissue Shape in the Developing Appendages of Drosophila

    PubMed Central

    Ray, Robert P.; Matamoro-Vidal, Alexis; Ribeiro, Paulo S.; Tapon, Nic; Houle, David; Salazar-Ciudad, Isaac; Thompson, Barry J.

    2015-01-01

    Summary How tissues acquire their characteristic shape is a fundamental unresolved question in biology. While genes have been characterized that control local mechanical forces to elongate epithelial tissues, genes controlling global forces in epithelia have yet to be identified. Here, we describe a genetic pathway that shapes appendages in Drosophila by defining the pattern of global tensile forces in the tissue. In the appendages, shape arises from tension generated by cell constriction and localized anchorage of the epithelium to the cuticle via the apical extracellular-matrix protein Dumpy (Dp). Altering Dp expression in the developing wing results in predictable changes in wing shape that can be simulated by a computational model that incorporates only tissue contraction and localized anchorage. Three other wing shape genes, narrow, tapered, and lanceolate, encode components of a pathway that modulates Dp distribution in the wing to refine the global force pattern and thus wing shape. PMID:26190146

  8. K+ homeostasis and central pattern generation in the metathoracic ganglion of the locust.

    PubMed

    Rodgers, Corinne I; Labrie, John D; Robertson, R Meldrum

    2009-07-01

    Stress-induced arrest of ventilatory motor pattern generation is tightly correlated with an abrupt increase in extracellular potassium concentration ([K+]o) within the metathoracic neuropil of the locust, Locusta migratoria. Na+/K+-ATPase inhibition with ouabain elicits repetitive surges of [K+]o that coincide with arrest and recovery of motor activity. Here we show that ouabain induces repetitive [K+]o events in a concentration-dependent manner. 10(-5)M, 10(-4)M, and 10(-3)M ouabain was bath-applied in semi-intact locust preparations. 10(-4)M and 10(-3)M ouabain reliably induced repetitive [K+]o events whereas 10(-5)M ouabain had no significant effect. In comparison to 10(-4)M ouabain, 10(-3)M ouabain increased the number and hastened the time to onset of repetitive [K+]o waves, prolonged [K+]o event duration, increased resting [K+]o, and diminished the absolute value of [K+]o waves. Recovery of motor patterning following [K+]o events was less likely in 10(-3)M ouabain. In addition, we show that K+ channel inhibition using TEA suppressed the onset and decreased the amplitude of ouabain-induced repetitive [K+]o waves. Our results demonstrate that ventilatory circuit function in the locust CNS is dependent on the balance between mechanisms of [K+] accumulation and [K+] clearance. We suggest that with an imbalance in favour of accumulation the system tends towards a bistable state with transitions mediated by positive feedback involving voltage-dependent K+ channels. PMID:19482133

  9. A Simulation of Generation Investment Planning Development under Competitive Environment

    NASA Astrophysics Data System (ADS)

    Matsumoto, Akira; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

    Several new generation companies such as PPS (Power Producer and Supplier) and IPP (Independent Power Producer) are emerging due to the deregulation and liberalization of the power industry. One of the most important concerns after the deregulation is decline of investment for power plant construction due to uncertainties associated with the power market. Development of power stations should be planned considering short-term and long term trends of power market. This paper focuses on the power stations development issues under competitive environment and proposes a simulation method of power stations development. The developed simulation tool can deal the interactions among each player's both short-term and long-term strategies.

  10. Thermoelectric Materials Development for Low Temperature Geothermal Power Generation

    DOE Data Explorer

    Tim Hansen

    2016-01-29

    Data includes characterization results for novel thermoelectric materials developed specifically for power generation from low temperature geothermal brines. Materials characterization data includes material density, thickness, resistance, Seebeck coefficient. This research was carried out by Novus Energy Partners in Cooperation with Southern Research Institute for a Department of Energy Sponsored Project.

  11. RICOR development of the next generation highly reliable rotary cryocooler

    NASA Astrophysics Data System (ADS)

    Regev, Itai; Nachman, Ilan; Livni, Dorit; Riabzev, Sergey; Filis, Avishai; Segal, Victor

    2016-05-01

    Early rotary cryocoolers were designed for the lifetime of a few thousands operating hours. Ricor K506 model's life expectancy was only 5,000 hours, then the next generation K508 model was designed to achieve 10,000 operating hours in basic conditions, while the modern K508N was designed for 20,000 operating hours. Nowadays, the new challenges in the field of rotary cryocoolers require development of a new generation cooler that could compete with the linear cryocooler reliability, achieving the lifetime goal of 30,000 operating hours, and even more. Such new advanced cryocooler can be used for upgrade existing systems, or to serve the new generation of high-temperature detectors that are currently under development, enabling the cryocooler to work more efficiently in the field. The improvement of the rotary cryocooler reliability is based on a deep analysis and understating of the root failure causes, finding solutions to reduce bearings wear, using modern materials and lubricants. All of those were taken into consideration during the development of the new generation rotary coolers. As a part of reliability challenges, new digital controller was also developed, which allows new options, such as discrete control of the operating frequency, and can extend the cooler operating hours due to new controlling technique. In addition, the digital controller will be able to collect data during cryocooler operation, aiming end of life prediction.

  12. Generativity-Stagnation: Development of a Status Model.

    ERIC Educational Resources Information Center

    Bradley, Cheryl L.

    1997-01-01

    Reviews theoretical and empirical developments in Erik Erikson's construct of generativity-stagnation. Presents a five-category model describing styles of resolving the issue using combinations of level of involvement or active concern for the growth of self and others; and level of inclusivity or scope of caregiving concern. Discusses model in…

  13. Beyond Idea Generation: The Power of Groups in Developing Ideas

    ERIC Educational Resources Information Center

    McMahon, Kibby; Ruggeri, Azzurra; Kämmer, Juliane E.; Katsikopoulos, Konstantinos V.

    2016-01-01

    Brainstorming research has claimed that individuals are more creative than groups. However, these conclusions are largely based on measuring creativity by the number of ideas generated, and researchers have tended to neglect other important components of creativity, such as the quality of developed ideas. These studies aim to address this gap in…

  14. Development and Design of a Dynamic Multimedia Item Generation Mechanism

    ERIC Educational Resources Information Center

    Weng, Ting-Sheng

    2012-01-01

    This research applies multimedia technology to design a dynamic item generation method that can adaptively adjust the difficulty level of items according to the level of the testee. The method is based on interactive testing software developed by Flash Actionscript, and provides a testing solution for users by automatically distributing items of…

  15. Expression Patterns of Extracellular Matrix Proteins during Posterior Commissure Development

    PubMed Central

    Stanic, Karen; Saldivia, Natalia; Förstera, Benjamín; Torrejón, Marcela; Montecinos, Hernán; Caprile, Teresa

    2016-01-01

    Extracellular matrix (ECM) molecules are pivotal for central nervous system (CNS) development, facilitating cell migration, axonal growth, myelination, dendritic spine formation, and synaptic plasticity, among other processes. During axon guidance, the ECM not only acts as a permissive or non-permissive substrate for navigating axons, but also modulates the effects of classical guidance cues, such as netrin or Eph/ephrin family members. Despite being highly important, little is known about the expression of ECM molecules during CNS development. Therefore, this study assessed the molecular expression patterns of tenascin, HNK-1, laminin, fibronectin, perlecan, decorin, and osteopontin along chick embryo prosomere 1 during posterior commissure development. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. Located in the dorso-caudal portion of prosomere 1, posterior commissure axons primarily arise from the neurons of basal pretectal nuclei that run dorsally to the roof plate midline, where some turn toward the ipsilateral side. Expressional analysis of ECM molecules in this area these revealed to be highly arranged, and molecule interactions with axon fascicles suggested involvement in processes other than structural support. In particular, tenascin and the HNK-1 epitope extended in ventro-dorsal columns and enclosed axons during navigation to the roof plate. Laminin and osteopontin were expressed in the midline, very close to axons that at this point must decide between extending to the contralateral side or turning to the ipsilateral side. Finally, fibronectin, decorin, and perlecan appeared unrelated to axonal pathfinding in this region and were instead restricted to the external limiting membrane. In summary, the present report provides evidence for an intricate expression of different extracellular molecules that may cooperate in guiding posterior commissure axons. PMID:27733818

  16. Differential recruitment of limb patterning genes during development and diversification of beetle horns

    PubMed Central

    Moczek, Armin P.; Rose, Debra J.

    2009-01-01

    The origins of novel complex phenotypes represent one of the most fundamental, yet largely unresolved, issues in evolutionary biology. Here we explore the developmental genetic regulation of beetle horns, a class of traits that lacks obvious homology to traits in other insects. Furthermore, beetle horns are remarkably diverse in their expression, including sexual dimorphisms, male dimorphisms, and interspecific differences in location of horn expression. At the same time, beetle horns share aspects of their development with that of more traditional appendages. We used larval RNA interference-mediated gene function analysis of 3 cardinal insect appendage patterning genes,dachshund, homothorax, and Distal-less, to investigate their role in development and diversification of beetle horns within and between species. Transcript depletion of all 3 patterning genes generated phenotypic effects very similar to those documented in previous studies that focused on general insect development. In addition, we found that Distal-less and homothorax, but not dachshund, regulate horn expression in a species-, sex-, body region-, and body size-dependent manner. Our results demonstrate differential co-option of appendage patterning genes during the evolution and radiation of beetle horns. Furthermore, our results illustrate that regulatory genes whose functions are otherwise highly conserved nevertheless retain the capacity to acquire additional functions, and that little phylogenetic distance appears necessary for the evolution of sex- and species-specific differences in these functions. PMID:19451631

  17. Laser-induced generation of micrometer-sized luminescent patterns on rare-earth-doped amorphous films

    SciTech Connect

    Zanatta, A.R.; Ribeiro, C.T.M.

    2004-12-01

    Room-temperature photoluminescence has been achieved from rare-earth-doped amorphous (a-) GeN films. The samples were prepared by the radio-frequency-sputtering method, and light emission from the rare-earth (RE) centers was obtained after irradiating the films with a highly focused laser beam. As a result of this laser annealing procedure, almost circular holes with approximately 1-{mu}m diameter were produced on the surface of the a-GeN films. The area nearby these holes correspond to crystalline Ge and coincide with the regions, where relatively strong RE-related luminescence takes place. These laser-annealed areas can be easily and conveniently managed in order to generate different microscopic luminescent patterns. Depending on the RE ion employed, visible and near-infrared light emission were obtained from the patterns so produced. The development of these micrometer-sized luminescent centers, as well as their probable mechanisms of excitation-recombination, will be presented and discussed. The importance of the current experimental results to future technological applications such as microdevices, for example, will also be outlined.

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

    NASA Technical Reports Server (NTRS)

    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).

  19. Steam generator tubing development for commercial fast breeder reactors

    SciTech Connect

    Sessions, C.E.; Uber, C.F.

    1981-11-01

    The development work to design, manufacture, and evaluate pre-stressed double-wall 2/one quarter/ Cr-1 Mo steel tubing for commercial fast breeder reactor steam generator application is discussed. The Westinghouse plan for qualifying tubing vendors to produce this tubing is described. The results achieved to date show that a long length pre-stressed double-wall tube is both feasible and commercially available. The evaluation included structural analysis and experimental measurement of the pre-stress within tubes, as well as dimensional, metallurgical, and interface wear tests of tube samples produced. This work is summarized and found to meet the steam generator design requirements. 10 refs.

  20. Development of a new generation of optical slope measuring profiler

    SciTech Connect

    Yashchuk, Valeriy V.; Takacs, Peter Z.; McKinney, Wayne R.; Assoufid, Lahsen

    2010-07-09

    We overview the results of a broad US collaboration, including all DOE synchrotron labs (ALS, APS, BNL, NSLS-II, LLNL, LCLS), major industrial vendors of x-ray optics (InSync, Inc., SSG Precision Optronics-Tinsley, Inc., Optimax Systems, Inc.), and with active participation of HBZ-BESSY-II optics group, on development of a new generation slope measuring profiler -- the optical slope measuring system (OSMS). The desired surface slope measurement accuracy of the instrument is<50 nrad (absolute) that is adequate to the current and foreseeable future needs for metrology of x-ray optics for the next generation of light sources.

  1. [Development of multi-function ECG signal generator].

    PubMed

    Cheng, F; Wei, Y X

    2000-07-01

    This paper describes the development of a portable multi-function ECG signal generator, which is based on micro-controller. It uses technique of LCD screen, and realizes man-machine interaction by keyboard. In constructing and disposing data module of the ECG signal, Eigen-heartbeat Code mapping method gets ROM saved greatly. Therefore it can generate all kinds of user-defined ECG signal sequence with no extension of on-board memory chips. This system can also simulate kinds of ECG signals, which have various heart rates and symptoms. It can meet the needs of researching and maintenance of kinds of ECG instruments. PMID:12583134

  2. Development of a Positron Generator Dedicated to Materials Science Applications

    NASA Astrophysics Data System (ADS)

    Rey, Jean-Michel G.; Barthe, Marie-France; Debu, Pascal; Desgardin, Pierre; Echegut, Patrick; Liszkay, Laszlo; Pérez, Patrice; Sacquin, Yves; Visière, Serge

    Positron beams are getting increasing interest for materials science and for fundamental research. Recent progress on positron production using a compact electron accelerator made at CEA-IRFU for the GBAR experiment is providing new prospect for material analysis and non-destructive testing technology using positrons. CNRS-CEMHTI is defining a long term strategy to boost its positron laboratory using an upgraded version of the CEA positron generator manufactured by the POSITHÔT company. This new generator is designed to produce between 2 and 3 x 107 slow positrons per second to feed in parallel several experiments. It will be presented here as well as the future beam developments.

  3. The Development of Sex-Related Fantasy Patterns

    ERIC Educational Resources Information Center

    Cramer, Phebe; Bryson, Jane

    1973-01-01

    Study supports the hypothesis that boys and girls, at the time they enter school, do not show the sex-related patterns of fantasy that have been found to differentiate adult men and women. By the age of about 9, sexual differentiation in fantasy patterns is clearly evident. (Authors/CB)

  4. Development of a novel protocol for generating flavivirus reporter particles.

    PubMed

    Fernández, Igor Velado; Okamoto, Natsumi; Ito, Aki; Fukuda, Miki; Someya, Azusa; Nishino, Yosii; Sasaki, Nobuya; Maeda, Akihiko

    2014-11-01

    Infection with West Nile virus (WNV), a mosquito-borne flavivirus, is a growing public and animal health concern worldwide. Prevention, diagnosis and treatment strategies for the infection are urgently required. Recently, viral reverse genetic systems have been developed and applied to clinical WNV virology. We developed a protocol for generating reporter virus particles (RVPs) of WNV with the aim of overcoming two major problems associated with conventional protocols, the difficulty in generating RVPs due to the specific skills required for handling RNAs, and the potential for environmental contamination by antibiotic-resistant genes encoded within the genome RNA of the RVPs. By using the proposed protocol, cells were established in which the RVP genome RNA is replicated constitutively and does not encode any antibiotic-resistant genes, and used as the cell supply for RVP genome RNA. Generation of the WNV RVPs requires only the simple transfection of the expression vectors for the viral structural proteins into the cells. Therefore, no RNA handling is required in this protocol. The WNV RVP yield obtained using this protocol was similar that obtained using the conventional protocol. According to these results, the newly developed protocol appears to be a good alternative for the generation of WNV RVPs, particularly for clinical applications.

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

    PubMed

    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.

  6. Pattern Scaling for Developing Change Scenarios in Water Supply Studies

    NASA Astrophysics Data System (ADS)

    Anandhi, A.; Pierson, D.; Frie, A.

    2014-12-01

    Change factor methodology (CFM), or delta change factor methodology, is a type of pattern scaling. Although a variety of methods are available to develop scenarios, CFMs are widely used for their ease and speed of application and their capability to directly scale local data according to changes suggested by the global climate model (GCM) scenarios. Change factors (CFs) can be calculated and used in a number of ways to estimate future climate scenarios, but no clear guidelines are available in the literature to decide which methodologies are most suitable for different applications. This study compares and contrasts several categories of CFM (additive versus multiplicative and single versus multiple) for a number of climate variables. The study employs several theoretical examples as well as an applied study from the New York City water supply. Results show that in cases where the frequency distribution of the GCM baseline climate is close to the frequency distribution of the observed climate, or when the frequency distribution of the GCM future climate is close to the frequency distribution of the GCM baseline climate, additive and multiplicative single CFMs provide comparable results. Two options to guide the choice of CFM are suggested: the first is a detailed methodological analysis for choosing the most appropriate CFM, and the second is a default method for circumstances in which a detailed methodological analysis is too cumbersome.

  7. Speech development patterns and phonological awareness in preschool children.

    PubMed

    Mann, Virginia A; Foy, Judith G

    2007-06-01

    To examine the association between speech production and early literacy skills, this study of 102 preschool children looked at phonological awareness in relation to whether children were delayed, typical, or advanced in their articulation of consonants. Using a developmental typology inspired by some of the literature on speech development (Kahn and Lewis, The Kahn-Lewis phonological analysis, 1986; Shriberg, Journal of Speech and Hearing Research 36(1):105-140, 1993a), we found that failure to master the early-8 consonants and a greater prevalence of certain types of production errors were associated with deficient phonological awareness. We also found that children who made no consonant errors had advanced phonological awareness relative to other children in the sample. In all cases, both productive speech patterns and speech errors were more closely linked with rhyme awareness than with phoneme awareness. The association between speech production and rhyme awareness may provide some new directions for the early preschool assessment of risk for reading problems. PMID:17849216

  8. Multislit interference patterns in high-order harmonic generation in C{sub 60}

    SciTech Connect

    Ciappina, M. F.; Becker, A.; Jaron-Becker, A.

    2007-12-15

    We study high-order harmonic generation in C{sub 60} molecules interacting with a linearly polarized intense short laser pulse at near- and mid-infrared wavelengths, using an extension of the so-called three-step or Lewenstein model to the molecular case. The results exhibit modulations in the plateaus of the spectra at the longer wavelengths, which are present for ensembles of aligned as well as randomly oriented fullerenes. The analysis of the results show that the minima can be explained by a multislit interference effect arising from the contributions of the 60 atomic centers to the dipole moment. Good agreement between the positions of the minima in the spectra obtained in the length gauge are found with those of the recombination matrix element, but not for those in the velocity gauge calculations. We further use a simple spherical model to analyze how geometrical information, such as the radius of the fullerene cage, can be obtained from the interference pattern in the harmonic spectra.

  9. Generation of Venus reporter knock-in mice revealed MAGI-2 expression patterns in adult mice.

    PubMed

    Ihara, Kan-ichiro; Nishimura, Tomoki; Fukuda, Tomokazu; Ookura, Tetsuya; Nishimori, Katsuhiko

    2012-01-01

    The membrane-associated guanylate kinase inverted 2 (MAGI-2) protein, which is known to localize at the tight junction of epithelial cells, contains multiple copies of the PDZ and WW domains in its structure. Although the expression pattern of Magi2 mRNA in representative organs has been previously published, its detailed cellular distribution at the histological level remains unknown. Such detailed information would be useful to clarify the biological function of MAGI-2. Here, we report the generation of Venus reporter knock-in mice for Magi2 in which exon 6 of the gene was substituted by the Venus-encoding sequence. We detected the expression of the Venus reporter protein in kidney podocytes from these knock-in mice. We also detected Venus reporter protein expression in spermatids within the testes and within neurons in various regions of the brain. Detection of the reporter protein from these diverse locations indicated the endogenous expression of MAGI-2 in these tissues. Our data suggested a potential function of MAGI-2 in the glomerular filtration process and sperm cell maturation. These data indicate that the Venus reporter knock-in mouse for Magi2 is a useful model for the further study of Magi2 gene function.

  10. The design and development of a third generation OSEE instrument

    NASA Astrophysics Data System (ADS)

    Perey, D. F.; Yost, W. T.; Stone, F. D.; Welch, C. S.; Scales, E.; Gasser, E. S.; Joe, E.; Goodman, T.; Pascual, X.; Hefner, B.

    1995-03-01

    Optically Stimulated Electron Emission (OSEE) has been used to quantify surface contamination in the aerospace community. As advances are made towards the understanding of OSEE, it is desirable to incorporate technological advances with succeeding generations of instrumentation, so that improvements in the practical application of OSEE may be disseminated among the user community. Several studies undertaken by Yost, Welch, Abedin and others have expanded the knowledge base related to the underlying principles of OSEE. The conclusions of these studies, together with inputs from the user community were the foundation upon which the development of a third generation OSEE instrument was based. This manuscript describes the significant improvements incorporated into a third generation OSEE instrument as well as the elements unique to its design.

  11. The design and development of a third generation OSEE instrument

    NASA Technical Reports Server (NTRS)

    Perey, D. F.; Yost, W. T.; Stone, F. D.; Welch, C. S.; Scales, E.; Gasser, E. S.; Joe, E.; Goodman, T.; Pascual, X.; Hefner, B.

    1995-01-01

    Optically Stimulated Electron Emission (OSEE) has been used to quantify surface contamination in the aerospace community. As advances are made towards the understanding of OSEE, it is desirable to incorporate technological advances with succeeding generations of instrumentation, so that improvements in the practical application of OSEE may be disseminated among the user community. Several studies undertaken by Yost, Welch, Abedin and others have expanded the knowledge base related to the underlying principles of OSEE. The conclusions of these studies, together with inputs from the user community were the foundation upon which the development of a third generation OSEE instrument was based. This manuscript describes the significant improvements incorporated into a third generation OSEE instrument as well as the elements unique to its design.

  12. Development of 30 kVA class fully superconducting generator

    SciTech Connect

    Tsukamoto, O.; Amemiya, N.; Takao, T. . Faculty of Engineering); Akita, S. ); Ohishi, K.; Shimuzu, H.; Tanaka, Y. ); Uchikawa, Y. )

    1992-01-01

    This paper reports that the authors are developing a 4 poles 30 kVA class fully superconducting generator to investigate the characteristics of superconducting armature winding subject to the rotating magnetic field produced by the superconducting rotor and behavior of a superconducting generator connected to an electric power utility grid. A static test of the armature winding have been performed by applying 50 Hz AC current. AC quench currents of the armature windings have reached to 200 Arms after several quenches which was well over the rated current. A static test of the field windings have been also performed to verify its rated performance. In the paper, detailed configurations and electrical test results of the generator are shown.

  13. Development and Buildup of a Stirling Radioisotope Generator Electrical Simulator

    NASA Technical Reports Server (NTRS)

    Prokop, Norman F.; Krasowski, Michael J.; Greer, Lawrence C.; Flatico, Joseph M.; Spina, Dan C.

    2008-01-01

    This paper describes the development of a Stirling Radioisotope Generator (SRG) Simulator for use in a prototype lunar robotic rover. The SRG developed at NASA Glenn Research Center (GRC) is a promising power source for the robotic exploration of the sunless areas of the moon. The simulator designed provides a power output similar to the SRG output of 5.7 A at 28 Vdc, while using ac wall power as the input power source. The designed electrical simulator provides rover developers the physical and electrical constraints of the SRG supporting parallel development of the SRG and rover. Parallel development allows the rover design team to embrace the SRG s unique constraints while development of the SRG is continued to a flight qualified version.

  14. A framework for prevention: changing health-damaging to health-generating life patterns.

    PubMed Central

    Milio, N

    1976-01-01

    A set of propositions is offered to provide a frame of reference for proposed strategies to improve healthful behavior by placing personal choice-making in the context of societal option-setting. The health status of populations at a given point in time is seen as a result of customary personal choice-making. These choices in turn are limited by both the perceived and actual options available to individuals, depending on their personal and their community's resources, from which to make choices. Most people, most of the time will make the easiest choices, i.e., will do the things, develop the patterns or life-styles, which seem to cost them less and/or from which they will gain more of what they value in tangible and/or intangible terms. PMID:1275116

  15. An Experimental and Theoretical Study of Fracture Patterns and Particle Motion Generated by Underground Explosions

    NASA Astrophysics Data System (ADS)

    Mihaly, J. M.; Rosakis, A.; Sammis, C. G.; Bhat, H.

    2013-12-01

    Fracture patterns and local particle velocities produced by point explosions in very brittle 'candy glass' plates are compared to those numerically predicted using a dynamic micro-mechanical damage mechanics model, developed by Bhat, Rosakis and Sammis, J. Appl. Mech., 2012. Empirically measured material properties for candy glass facilitate direct comparison between the numerical simulation and experimental results. The evolution of fracture damage produced in experiments is observed using high-speed digital photography, which also images resultant wave fronts (for both P and S). Local particle velocities are also recorded at up to three points using laser vibrometers. Numerical results for the spatial extent of circumferential and radial cracking, in addition to the growth-rate of individual radial cracks, are representative of experimental observations. Wave reflections from the plate edges are observed in both experiment and numerical simulation to affect the expansion of radial cracks. Numerically predicted wave-forms and arrivals compare well with experimental results observed at select points.

  16. Recent results from extreme ultraviolet lithography patterned mask inspection for 11 nm half-pitch generation using projection electron microscope system

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    Extreme ultraviolet lithography (EUVL) is a promising technique for 1X nm half-pitch (hp) generation lithography. The inspection of patterned EUVL masks is one of the main issues that must be addressed during mask fabrication for manufacture of devices with 11 nm hp feature sizes. We have already designed projection electron microscope (PEM) optics that have been integrated into a new inspection system called Model EBEYE-V30 (where "Model EBEYE" is an EBARA's model code) and this system seems quite promising for 16 nm hp generation EUVL patterned mask inspection. The defect inspection sensitivity of this system was evaluated via capture of an electron image that was generated at the mask by focusing the image through the projection optics onto a time-delay integration (TDI) image sensor. For increased throughput and higher defect detection sensitivity, a new electron-sensitive area image sensor with a high-speed data processing unit, a bright and stable electron source, and a simultaneous deflector for the image capture area that follows the mask scanning motion have been developed. Using a combination of synchronous deflection and mask scanning, the image can be integrated into both the fixed area image sensor and the TDI image sensor. We describe our experimental results for EUV patterned mask inspection using the above system. Elements have been developed for inspection tool integration and the designed specification has been verified. The system performance demonstrates the defect detectability required for 11 nm hp generation EUVL masks.

  17. Development of Spatial Distribution Patterns by Biofilm Cells

    PubMed Central

    Haagensen, Janus A. J.; Hansen, Susse K.; Christensen, Bjarke B.; Molin, Søren

    2015-01-01

    Confined spatial patterns of microbial distribution are prevalent in nature, such as in microbial mats, soil communities, and water stream biofilms. The symbiotic two-species consortium of Pseudomonas putida and Acinetobacter sp. strain C6, originally isolated from a creosote-polluted aquifer, has evolved a distinct spatial organization in the laboratory that is characterized by an increased fitness and productivity. In this consortium, P. putida is reliant on microcolonies formed by Acinetobacter sp. C6, to which it attaches. Here we describe the processes that lead to the microcolony pattern by Acinetobacter sp. C6. Ecological spatial pattern analyses revealed that the microcolonies were not entirely randomly distributed and instead were arranged in a uniform pattern. Detailed time-lapse confocal microscopy at the single-cell level demonstrated that the spatial pattern was the result of an intriguing self-organization: small multicellular clusters moved along the surface to fuse with one another to form microcolonies. This active distribution capability was dependent on environmental factors (carbon source and oxygen) and historical contingency (formation of phenotypic variants). The findings of this study are discussed in the context of species distribution patterns observed in macroecology, and we summarize observations about the processes involved in coadaptation between P. putida and Acinetobacter sp. C6. Our results contribute to an understanding of spatial species distribution patterns as they are observed in nature, as well as the ecology of engineered communities that have the potential for enhanced and sustainable bioprocessing capacity. PMID:26116674

  18. Versatile pattern generation of periodic, high aspect ratio Si nanostructure arrays with sub-50-nm resolution on a wafer scale

    PubMed Central

    2013-01-01

    We report on a method of fabricating variable patterns of periodic, high aspect ratio silicon nanostructures with sub-50-nm resolution on a wafer scale. The approach marries step-and-repeat nanoimprint lithography (NIL) and metal-catalyzed electroless etching (MCEE), enabling near perfectly ordered Si nanostructure arrays of user-defined patterns to be controllably and rapidly generated on a wafer scale. Periodic features possessing circular, hexagonal, and rectangular cross-sections with lateral dimensions down to sub-50 nm, in hexagonal or square array configurations and high array packing densities up to 5.13 × 107 structures/mm2 not achievable by conventional UV photolithography are fabricated using this top-down approach. By suitably tuning the duration of catalytic etching, variable aspect ratio Si nanostructures can be formed. As the etched Si pattern depends largely on the NIL mould which is patterned by electron beam lithography (EBL), the technique can be used to form patterns not possible with self-assembly methods, nanosphere, and interference lithography for replication on a wafer scale. Good chemical resistance of the nanoimprinted mask and adhesion to the Si substrate facilitate good pattern transfer and preserve the smooth top surface morphology of the Si nanostructures as shown in TEM. This approach is suitable for generating Si nanostructures of controlled dimensions and patterns, with high aspect ratio on a wafer level suitable for semiconductor device production. PMID:24289275

  19. Versatile pattern generation of periodic, high aspect ratio Si nanostructure arrays with sub-50-nm resolution on a wafer scale

    NASA Astrophysics Data System (ADS)

    Ho, Jian-Wei; Wee, Qixun; Dumond, Jarrett; Tay, Andrew; Chua, Soo-Jin

    2013-12-01

    We report on a method of fabricating variable patterns of periodic, high aspect ratio silicon nanostructures with sub-50-nm resolution on a wafer scale. The approach marries step-and-repeat nanoimprint lithography (NIL) and metal-catalyzed electroless etching (MCEE), enabling near perfectly ordered Si nanostructure arrays of user-defined patterns to be controllably and rapidly generated on a wafer scale. Periodic features possessing circular, hexagonal, and rectangular cross-sections with lateral dimensions down to sub-50 nm, in hexagonal or square array configurations and high array packing densities up to 5.13 × 107 structures/mm2 not achievable by conventional UV photolithography are fabricated using this top-down approach. By suitably tuning the duration of catalytic etching, variable aspect ratio Si nanostructures can be formed. As the etched Si pattern depends largely on the NIL mould which is patterned by electron beam lithography (EBL), the technique can be used to form patterns not possible with self-assembly methods, nanosphere, and interference lithography for replication on a wafer scale. Good chemical resistance of the nanoimprinted mask and adhesion to the Si substrate facilitate good pattern transfer and preserve the smooth top surface morphology of the Si nanostructures as shown in TEM. This approach is suitable for generating Si nanostructures of controlled dimensions and patterns, with high aspect ratio on a wafer level suitable for semiconductor device production.

  20. Development and embryonic pattern of body wall musculature in the crassiclitellate Eisenia andrei (Annelida, Clitellata).

    PubMed

    Hunnekuhl, Vera S; Bergter, Annette; Purschke, Günter; Paululat, Achim

    2009-09-01

    During early development of Eisenia andrei (Crassiclitellata), a loose arrangement of primary circular and longitudinal muscles encloses the whole embryo. Circular muscles differentiate in an anterior-posterior progression creating a segmental pattern. Primary circular muscles emerge at the segmental borders while later in development the central part of each segment is filled with circular strands. Longitudinal muscles develop in an anterio-posterior manner as well, but by continuous lengthening. Muscle growth is not restricted by segmental boundaries. The development begins with one pair of prominent longitudinal muscles differentiating ventrally along the right and the left germ band. These first muscles provide a guiding structure for the parallel organization of the afterwards differentiating longitudinal musculature. Additional primary longitudinal muscles emerge and form, together with the initial circular muscles, the primary muscle grid of the embryo. During the following development, secondary longitudinal muscle strands develop and integrate themselves into the primary grid. Meanwhile the primary circular muscles split into thin strands in a ventral to dorsal progression. Thus, a fine structured mesh of circular and longitudinal muscles is generated. Compared to other "Oligochaeta", embryonic muscle patterns in E. andrei are adapted to the development of a lecithotrophic embryo. Nevertheless, two general characteristics of annelid muscle development become evident. The first is the segmental development of the circular muscles from a set of initial muscles situated at the segment borders. Second, there is a continuous development of primary longitudinal muscles starting at the anterior pole. At least one pair of main primary longitudinal strands is characteristic in Annelida. The space between all primary strands is filled with secondary longitudinal strands during further development.

  1. Analysis and Prediction of User Editing Patterns in Ontology Development Projects

    PubMed Central

    Wang, Hao; Tudorache, Tania; Dou, Dejing; Noy, Natalya F.; Musen, Mark A.

    2014-01-01

    The development of real-world ontologies is a complex undertaking, commonly involving a group of domain experts with different expertise that work together in a collaborative setting. These ontologies are usually large scale and have complex structures. To assist in the authoring process, ontology tools are key at making the editing process as streamlined as possible. Being able to predict confidently what the users are likely to do next as they edit an ontology will enable us to focus and structure the user interface accordingly and to facilitate more efficient interaction and information discovery. In this paper, we use data mining, specifically the association rule mining, to investigate whether we are able to predict the next editing operation that a user will make based on the change history. We simulated and evaluated continuous prediction across time using sliding window model. We used the association rule mining to generate patterns from the ontology change logs in the training window and tested these patterns on logs in the adjacent testing window. We also evaluated the impact of different training and testing window sizes on the prediction accuracies. At last, we evaluated our prediction accuracies across different user groups and different ontologies. Our results indicate that we can indeed predict the next editing operation a user is likely to make. We will use the discovered editing patterns to develop a recommendation module for our editing tools, and to design user interface components that better fit with the user editing behaviors. PMID:26052350

  2. Development and optimization of a stove-powered thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Mastbergen, Dan

    Almost a third of the world's population still lacks access to electricity. Most of these people use biomass stoves for cooking which produce significant amounts of wasted thermal energy, but no electricity. Less than 1% of this energy in the form of electricity would be adequate for basic tasks such as lighting and communications. However, an affordable and reliable means of accomplishing this is currently nonexistent. The goal of this work is to develop a thermoelectric generator to convert a small amount of wasted heat into electricity. Although this concept has been around for decades, previous attempts have failed due to insufficient analysis of the system as a whole, leading to ineffective and costly designs. In this work, a complete design process is undertaken including concept generation, prototype testing, field testing, and redesign/optimization. Detailed component models are constructed and integrated to create a full system model. The model encompasses the stove operation, thermoelectric module, heat sinks, charging system and battery. A 3000 cycle endurance test was also conducted to evaluate the effects of operating temperature, module quality, and thermal interface quality on the generator's reliability, lifetime and cost effectiveness. The results from this testing are integrated into the system model to determine the lowest system cost in $/Watt over a five year period. Through this work the concept of a stove-based thermoelectric generator is shown to be technologically and economically feasible. In addition, a methodology is developed for optimizing the system for specific regional stove usage habits.

  3. Dynamical patterning modules: physico-genetic determinants of morphological development and evolution

    NASA Astrophysics Data System (ADS)

    Newman, Stuart A.; Bhat, Ramray

    2008-03-01

    The shapes and forms of multicellular organisms arise by the generation of new cell states and types and changes in the numbers and rearrangements of the various kinds of cells. While morphogenesis and pattern formation in all animal species are widely recognized to be mediated by the gene products of an evolutionarily conserved 'developmental-genetic toolkit', the link between these molecular players and the physics underlying these processes has been generally ignored. This paper introduces the concept of 'dynamical patterning modules' (DPMs), units consisting of one or more products of the 'toolkit' genes that mobilize physical processes characteristic of chemically and mechanically excitable meso- to macroscopic systems such as cell aggregates: cohesion, viscoelasticity, diffusion, spatiotemporal heterogeneity based on lateral inhibition and multistable and oscillatory dynamics. We suggest that ancient toolkit gene products, most predating the emergence of multicellularity, assumed novel morphogenetic functions due to change in the scale and context inherent to multicellularity. We show that DPMs, acting individually and in concert with each other, constitute a 'pattern language' capable of generating all metazoan body plans and organ forms. The physical dimension of developmental causation implies that multicellular forms during the explosive radiation of animal body plans in the middle Cambrian, approximately 530 million years ago, could have explored an extensive morphospace without concomitant genotypic change or selection for adaptation. The morphologically plastic body plans and organ forms generated by DPMs, and their ontogenetic trajectories, would subsequently have been stabilized and consolidated by natural selection and genetic drift. This perspective also solves the apparent 'molecular homology-analogy paradox', whereby widely divergent modern animal types utilize the same molecular toolkit during development by proposing, in contrast to the Neo

  4. Decomposing risk: landscape structure and wolf behavior generate different predation patterns in two sympatric ungulates.

    PubMed

    Gervasi, Vincenzo; Sand, Hakan; Zimmermann, Barbara; Mattisson, Jenny; Wabakken, Petter; Linnell, John D C

    2013-10-01

    Recolonizing carnivores can have a large impact on the status of wild ungulates, which have often modified their behavior in the absence of predation. Therefore, understanding the dynamics of reestablished predator-prey systems is crucial to predict their potential ecosystem effects. We decomposed the spatial structure of predation by recolonizing wolves (Canis lupus) on two sympatric ungulates, moose (Alces alces) and roe deer (Capreolus capreolus), in Scandinavia during a 10-year study. We monitored 18 wolves with GPS collars, distributed over 12 territories, and collected records from predation events. By using conditional logistic regression, we assessed the contributions of three main factors, the utilization patterns of each wolf territory, the spatial distribution of both prey species, and fine-scale landscape structure, in determining the spatial structure of moose and roe deer predation risk. The reestablished predator-prey system showed a remarkable spatial variation in kill occurrence at the intra-territorial level, with kill probabilities varying by several orders of magnitude inside the same territory. Variation in predation risk was evident also when a spatially homogeneous probability for a wolf to encounter a prey was simulated. Even inside the same territory, with the same landscape structure, and when exposed to predation by the same wolves, the two prey species experienced an opposite spatial distribution of predation risk. In particular, increased predation risk for moose was associated with open areas, especially clearcuts and young forest stands, whereas risk was lowered for roe deer in the same habitat types. Thus, fine-scale landscape structure can generate contrasting predation risk patterns in sympatric ungulates, so that they can experience large differences in the spatial distribution of risk and refuge areas when exposed to predation by a recolonizing predator. Territories with an earlier recolonization were not associated with a lower

  5. Decomposing risk: landscape structure and wolf behavior generate different predation patterns in two sympatric ungulates.

    PubMed

    Gervasi, Vincenzo; Sand, Hakan; Zimmermann, Barbara; Mattisson, Jenny; Wabakken, Petter; Linnell, John D C

    2013-10-01

    Recolonizing carnivores can have a large impact on the status of wild ungulates, which have often modified their behavior in the absence of predation. Therefore, understanding the dynamics of reestablished predator-prey systems is crucial to predict their potential ecosystem effects. We decomposed the spatial structure of predation by recolonizing wolves (Canis lupus) on two sympatric ungulates, moose (Alces alces) and roe deer (Capreolus capreolus), in Scandinavia during a 10-year study. We monitored 18 wolves with GPS collars, distributed over 12 territories, and collected records from predation events. By using conditional logistic regression, we assessed the contributions of three main factors, the utilization patterns of each wolf territory, the spatial distribution of both prey species, and fine-scale landscape structure, in determining the spatial structure of moose and roe deer predation risk. The reestablished predator-prey system showed a remarkable spatial variation in kill occurrence at the intra-territorial level, with kill probabilities varying by several orders of magnitude inside the same territory. Variation in predation risk was evident also when a spatially homogeneous probability for a wolf to encounter a prey was simulated. Even inside the same territory, with the same landscape structure, and when exposed to predation by the same wolves, the two prey species experienced an opposite spatial distribution of predation risk. In particular, increased predation risk for moose was associated with open areas, especially clearcuts and young forest stands, whereas risk was lowered for roe deer in the same habitat types. Thus, fine-scale landscape structure can generate contrasting predation risk patterns in sympatric ungulates, so that they can experience large differences in the spatial distribution of risk and refuge areas when exposed to predation by a recolonizing predator. Territories with an earlier recolonization were not associated with a lower

  6. Surface mechanics mediate pattern formation in the developing retina.

    PubMed

    Hayashi, Takashi; Carthew, Richard W

    2004-10-01

    Pattern formation of biological structures involves organizing different types of cells into a spatial configuration. In this study, we investigate the physical basis of biological patterning of the Drosophila retina in vivo. We demonstrate that E- and N-cadherins mediate apical adhesion between retina epithelial cells. Differential expression of N-cadherin within a sub-group of retinal cells (cone cells) causes them to form an overall shape that minimizes their surface contact with surrounding cells. The cells within this group, in both normal and experimentally manipulated conditions, pack together in the same way as soap bubbles do. The shaping of the cone cell group and packing of its components precisely imitate the physical tendency for surfaces to be minimized. Thus, simple patterned expression of N-cadherin results in a complex spatial pattern of cells owing to cellular surface mechanics. PMID:15470418

  7. Development of a fourth generation predictive capability maturity model.

    SciTech Connect

    Hills, Richard Guy; Witkowski, Walter R.; Urbina, Angel; Rider, William J.; Trucano, Timothy Guy

    2013-09-01

    The Predictive Capability Maturity Model (PCMM) is an expert elicitation tool designed to characterize and communicate completeness of the approaches used for computational model definition, verification, validation, and uncertainty quantification associated for an intended application. The primary application of this tool at Sandia National Laboratories (SNL) has been for physics-based computational simulations in support of nuclear weapons applications. The two main goals of a PCMM evaluation are 1) the communication of computational simulation capability, accurately and transparently, and 2) the development of input for effective planning. As a result of the increasing importance of computational simulation to SNLs mission, the PCMM has evolved through multiple generations with the goal to provide more clarity, rigor, and completeness in its application. This report describes the approach used to develop the fourth generation of the PCMM.

  8. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    SciTech Connect

    King, D.A.

    1994-11-10

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan.

  9. NNSA Program Develops the Next Generation of Nuclear Security Experts

    SciTech Connect

    Brim, Cornelia P.; Disney, Maren V.

    2015-09-02

    NNSA is fostering the next generation of nuclear security experts is through its successful NNSA Graduate Fellowship Program (NGFP). NGFP offers its Fellows an exceptional career development opportunity through hands-on experience supporting NNSA mission areas across policy and technology disciplines. The one-year assignments give tomorrow’s leaders in global nuclear security and nonproliferation unparalleled exposure through assignments to Program Offices across NNSA.

  10. The ArF laser for the next-generation multiple-patterning immersion lithography supporting green operations

    NASA Astrophysics Data System (ADS)

    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.

  11. Effects of Pattern Matching, Pattern Discrimination, and Experience in the Development of Diagnostic Expertise.

    ERIC Educational Resources Information Center

    Papa, Frank; And Others

    1990-01-01

    In this study an artificial intelligence assessment tool used disease-by-feature frequency estimates to create disease prototypes for nine common causes of acute chest pain. The tool then used each subject's prototypes and a pattern-recognition-based decision-making mechanism to diagnose 18 myocardial infarction cases. (MLW)

  12. Development of Next Generation Segmented Thermoelectric Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Fleurial, J.; Caillat, T.; Ewell, R. C.

    2005-12-01

    Radioisotope thermoelectric generators have been used for space-based applications since 1961 with a total of 22 space missions that have successfully used RTGs for electrical power production. The key advantages of radioisotope thermoelectric generators (RTGs) are their long life, robustness, compact size, and high reliability. Thermoelectric converters are easily scalable, and possess a linear current-voltage curve, making power generation easy to control via a shunt regulator and shunt radiator. They produce no noise, vibration or torque during operation. These properties have made RTGs ideally suitable for autonomous missions in the extreme environments of outer space and on planetary surfaces. More advanced radioisotope power systems (RPS) with higher specific power (W/kg) and/or power output are desirable for future NASA missions, including the Europa Geophysical Orbiter mission. For the past few years, the Jet Propulsion Laboratory (JPL) has been developing more efficient thermoelectric materials and has demonstrated significant increases in the conversion efficiency of high temperature thermocouples, up to 14% when operated across a 975K to 300K temperature differential. In collaboration with NASA Glenn Research Center, universities (USC and UNM), Ceramic and Metal Composites Corporation and industrial partners, JPL is now planning to lead the research and development of advanced thermoelectric technology for integration into the next generations of RPS. Preliminary studies indicate that this technology has the potential for improving the RPS specific power by more than 50% over the current state-of-the-art multi-mission RTG being built for the Mars Science Laboratory mission. A second generation advanced RPS is projected at more than doubling the specific power.

  13. Focal high cell density generates a gradient of patterns in self-organizing vascular mesenchymal cells.

    PubMed

    Cheng, Henry; Reddy, Aneela; Sage, Andrew; Lu, Jinxiu; Garfinkel, Alan; Tintut, Yin; Demer, Linda L

    2012-01-01

    In embryogenesis, structural patterns, such as vascular branching, may form via a reaction-diffusion mechanism in which activator and inhibitor morphogens guide cells into periodic aggregates. We previously found that vascular mesenchymal cells (VMCs) spontaneously aggregate into nodular structures and that morphogen pairs regulate the aggregation into patterns of spots and stripes. To test the effect of a focal change in activator morphogen on VMC pattern formation, we created a focal zone of high cell density by plating a second VMC layer within a cloning ring over a confluent monolayer. After 24 h, the ring was removed and pattern formation monitored by phase-contrast microscopy. At days 2-8, the patterns progressed from uniform distributions to swirl, labyrinthine and spot patterns. Within the focal high-density zone (HDZ) and a narrow halo zone, cells aggregated into spot patterns, whilst in the outermost zone of the plate, cells formed a labyrinthine pattern. The area occupied by aggregates was significantly greater in the outermost zone than in the HDZ or halo. The rate of pattern progression within the HDZ increased as a function of its plating density. Thus, focal differences in cell density may drive pattern formation gradients in tissue architecture, such as vascular branching.

  14. Focal High Cell Density Generates a Gradient of Patterns in Self-Organizing Vascular Mesenchymal Cells

    PubMed Central

    Cheng, Henry; Reddy, Aneela; Sage, Andrew; Lu, Jinxiu; Garfinkel, Alan; Tintut, Yin; Demer, Linda

    2012-01-01

    In embryogenesis, structural patterns, such as vascular branching, may form via a reaction-diffusion mechanism in which activator and inhibitor morphogens guide cells into periodic aggregates. We previously found that vascular mesenchymal cells (VMC) spontaneously aggregate into nodular structures and that morphogen pairs regulate the aggregation into patterns of spots and stripes. To test the effect of a focal change in activator morphogen on VMC pattern formation, we created a focal zone of high cell density by plating a second layer VMC within a cloning ring over a confluent monolayer. After 24 hours, the ring was removed, and pattern formation monitored by phase-contrast microscopy. At days 2–8, the patterns progressed from uniform distributions to swirl, labyrinthine, and spot patterns. Within the focal high-density zone and a narrow halo zone, cells aggregated into spot patterns; in the outermost zone of the plate, cells formed a labyrinthine pattern. Area occupied by aggregates was significantly greater in the outermost zone than in the HDZ or halo. The rate of pattern progression within the HDZ increased as a function of its plating density. Thus, focal differences in cell density may drive pattern formation gradients in tissue architecture, such as vascular branching. PMID:22797747

  15. Neurochemical and neuroanatomical identification of central pattern generator neuron homologues in Nudipleura molluscs.

    PubMed

    Lillvis, Joshua L; Gunaratne, Charuni A; Katz, Paul S

    2012-01-01

    Certain invertebrate neurons can be identified by their behavioral functions. However, evolutionary divergence can cause some species to not display particular behaviors, thereby making it impossible to use physiological characteristics related to those behaviors for identifying homologous neurons across species. Therefore, to understand the neural basis of species-specific behavior, it is necessary to identify homologues using characteristics that are independent of physiology. In the Nudipleura mollusc Tritonia diomedea, Cerebral Neuron 2 (C2) was first described as being a member of the swim central pattern generator (CPG). Here we demonstrate that neurochemical markers, in conjunction with previously known neuroanatomical characteristics, allow C2 to be uniquely identified without the aid of electrophysiological measures. Specifically, C2 had three characteristics that, taken together, identified the neuron: 1) a white cell on the dorsal surface of the cerebral ganglion, 2) an axon that projected to the contralateral pedal ganglion and through the pedal commissure, and 3) immunoreactivity for the peptides FMRFamide and Small Cardioactive Peptide B. These same anatomical and neurochemical characteristics also uniquely identified the C2 homologue in Pleurobranchaea californica (called A1), which was previously identified by its analogous role in the Pleurobranchaea swim CPG. Furthermore, these characteristics were used to identify C2 homologues in Melibe leonina, Hermissenda crassicornis, and Flabellina iodinea, species that are phylogenetically closer to Tritonia than Pleurobranchaea, but do not display the same swimming behavior as Tritonia or Pleurobranchaea. These identifications will allow future studies comparing and contrasting the physiological properties of C2 across species that can and cannot produce the type of swimming behavior exhibited by Tritonia.

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

    PubMed

    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

  17. Massive alterations of the methylation patterns around DNA transposons in the first four generations of a newly formed wheat allohexaploid.

    PubMed

    Yaakov, Beery; Kashkush, Khalil

    2011-01-01

    Rapid and reproducible genomic changes can be induced during the early stages of the life of nascent allopolyploid species. In a previous study, it was shown that following allopolyploidization, cytosine methylation changes can affect up to 11% of the wheat genome. However, the methylation patterns around transposable elements (TEs) were never studied in detail. We used transposon methylation display (TMD) to assess the methylation patterns of CCGG sites flanking three TE families (Balduin, Apollo, and Thalos) in the first four generations of a newly formed wheat allohexaploid. In addition, transposon display (TD), using a methylation-insensitive restriction enzyme, was applied to search for genomic rearrangements at the TE insertion sites. We observed that up to 54% of CCGG sites flanking the three TE families showed changes in methylation patterns in the first four generations of a newly formed wheat allohexaploid, where hypermethylation was predominant. Over 70% of the changes in TMD patterns occurred in the first two generations of the newly formed allohexaploid. Furthermore, analysis of 555 TE insertion sites by TD and 18 cases by site-specific PCR revealed a full additive pattern in the allohexaploid, an indication for lack of massive rearrangements. These data indicate that following allopolyplodization, DNA-TE insertion sites can undergo a significantly high level of methylation changes compared with methylation changes of other genomic sequences.

  18. Development of Advanced Stirling Radioisotope Generator for Space Exploration

    NASA Technical Reports Server (NTRS)

    Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

    2007-01-01

    Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 to 7 We/kg, along with a 25 percent reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

  19. Development of Advanced Stirling Radioisotope Generator for Space Exploration

    NASA Astrophysics Data System (ADS)

    Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

    2007-01-01

    Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 We/kg to 7 We/kg, along with a 25% reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

  20. Developing Next Generation Natural Fracture Detection and Prediction Technology

    SciTech Connect

    R.L. Billingsley

    2005-05-01

    The purpose of the ''Next Generation'' project was to develop technology that will provide a quantitative description of natural fracture properties and locations in low-permeability reservoirs. The development of this technology has consistently been ranked as one of the highest priority needs by industry. Numerous researchers and resource assessment groups have stated that the ability to identify area where intense clusters of natural fractures co-exist with gas-charged sands, the so called ''sweet spots'', will be the key to unlocking the vast quantities of gas in-place contained in these low-permeability gas basins. To meet this technology need, the ''Next Generation'' project was undertaken with three performance criteria in mind: (1) provide an integrated assessment of the burial and tectonic stresses in a basin responsible for natural fracture genesis (using seismic data, a significantly modified application of geomechanics, and a discrete natural fracture generation model); (2) link the assessment of natural fracture properties and locations to the reservoir's fluid, storage and flow properties; and, (3) provide a reservoir simulation-based calculation of the gas (and water) production capacity of a naturally fractured reservoir system. Phase III of the ''Next Generation'' project entailed the performance of a field demonstration of the software in an ''exploration'' setting. The search for an Industry Partner willing to host an exploratory field demonstration was unsuccessful and Phase III was canceled effective May, 31, 2005. The failure to find an Industry Partner can be attributed to severe changes in the petroleum industry competitive environment between 1999 when the project was initiated and 2005 when further demonstration efforts were halted. The software was employed in portions of other, non-exploratory, projects underway during the development time period, and insights gained will be summarized here in lieu of a full field demonstration.

  1. Development of second-generation pressurized fluidized bed combustion process

    SciTech Connect

    Wolowodiuk, W.; Robertson, A.; Bonk, D.

    1995-12-01

    Under the sponsorship of the United States Department of Energy, Foster Wheeler Development Corporation, and its team members, Westinghouse, Gilbert/Commonwealth, and the Institute of Gas Technology are developing second-generation pressurized fluidized bed combustion technology capable of achieving net plant efficiency in excess of 45 percent based on the higher heating value of the coal. A three-phase program entails design and costing of a 500 MWe power plant and identification of developments needed to commercialize this technology (Phase 1), testing of individual components (Phase 2), and finally testing these components in an integrated mode (Phase 3). This paper briefly describes the results of the first two phases as well as the progress on the third phase. Since other projects which use the same technology are in construction or in negotiation stages-namely, the Power System Development Facility and the Four Rivers Energy Modernization Projects-brief descriptions of these are also included.

  2. The weaver gene expression affects neuronal generation patterns depending on age and encephalic region.

    PubMed

    Martí, Joaquín; Carmen Santa-Cruz, M; Bayer, Shirley A; Hervás, José P

    2006-04-01

    Cell generation and survival are investigated in three different neuronal populations of weaver mice: Purkinje and fastigial neurons in the cerebellum, and dopaminergic neurons in the substantia nigra pars compacta. Tritiated thymidine was supplied to pregnant females at the time that these neurons were being produced. Autoradiography was then applied on brain sections obtained from the control and weaver offspring at postnatal (P) day 8 and 90. This makes it possible to assess the differential survival of neurons that were born at distinct embryonic times on the basis of the proportion of labeled cells at two postnatal ages. When labeling profiles were measured at P8, the inferred time of origin was similar between +/+ and wv/wv genotypes for each neuronal population considered. The same occurred at P90 for Purkinje or fastigial neurons, but the labeling profiles of midbrain neurons were different between wild type and weaver homozygotes. There is already a substantial reduction in the number of Purkinje and fastigial cells at P8, but loss of dopaminergic neurons was only detected in 90-day-old weavers and, therefore, vulnerability is built into this midbrain neural system during its late postnatal development. Our results show that depletion of Purkinje and fastigial cells is random with respect to the time of their birth, whereas the weaver gene seems to be specifically targeting the late-generated dopaminergic neurons.

  3. Massively parallel E-beam inspection: enabling next-generation patterned defect inspection for wafer and mask manufacturing

    NASA Astrophysics Data System (ADS)

    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.

  4. Spongiosa primary development: a biochemical hypothesis by Turing patterns formations.

    PubMed

    López-Vaca, Oscar Rodrigo; Garzón-Alvarado, Diego Alexander

    2012-01-01

    We propose a biochemical model describing the formation of primary spongiosa architecture through a bioregulatory model by metalloproteinase 13 (MMP13) and vascular endothelial growth factor (VEGF). It is assumed that MMP13 regulates cartilage degradation and the VEGF allows vascularization and advances in the ossification front through the presence of osteoblasts. The coupling of this set of molecules is represented by reaction-diffusion equations with parameters in the Turing space, creating a stable spatiotemporal pattern that leads to the formation of the trabeculae present in the spongy tissue. Experimental evidence has shown that the MMP13 regulates VEGF formation, and it is assumed that VEGF negatively regulates MMP13 formation. Thus, the patterns obtained by ossification may represent the primary spongiosa formation during endochondral ossification. Moreover, for the numerical solution, we used the finite element method with the Newton-Raphson method to approximate partial differential nonlinear equations. Ossification patterns obtained may represent the primary spongiosa formation during endochondral ossification.

  5. Development of an intelligent controller for power generators

    NASA Astrophysics Data System (ADS)

    Maxted, Clive; Waller, Winston

    2005-01-01

    This paper is a description of the development of an embedded controller for high power industrial diesel generators. The aim of the project was to replace the existing discrete logic design by an intelligent versatile and user configurable control system. A prototype embedded PC controlled system was developed, capable of fully replacing the existing system, with a colour TFT display and keypad. Features include fully automatic generator control as before with status and alarm display and monitoring of engine parameters, along with data logging, remote communications and a means of analysing data. The unit was tested on the bench and on diesel generators for the core controlling functionality to prove compliance with the specifications. The results of the testing proved the unit's suitability as a replacement for the existing system in its intended environment. The significance of this study is that a low cost replacement solution has been found for an industrial application by transferring modern technological knowledge to a small business. The company are now able to build on the design and take it into production, reducing servicing and production costs.

  6. Systems, methods and apparatus for pattern matching in procedure development and verification

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G. (Inventor); Rash, James L. (Inventor); Rouff, Christopher A. (Inventor)

    2011-01-01

    Systems, methods and apparatus are provided through which, in some embodiments, a formal specification is pattern-matched from scenarios, the formal specification is analyzed, and flaws in the formal specification are corrected. The systems, methods and apparatus may include pattern-matching an equivalent formal model from an informal specification. Such a model can be analyzed for contradictions, conflicts, use of resources before the resources are available, competition for resources, and so forth. From such a formal model, an implementation can be automatically generated in a variety of notations. The approach can improve the resulting implementation, which, in some embodiments, is provably equivalent to the procedures described at the outset, which in turn can improve confidence that the system reflects the requirements, and in turn reduces system development time and reduces the amount of testing required of a new system. Moreover, in some embodiments, two or more implementations can be "reversed" to appropriate formal models, the models can be combined, and the resulting combination checked for conflicts. Then, the combined, error-free model can be used to generate a new (single) implementation that combines the functionality of the original separate implementations, and may be more likely to be correct.

  7. Development of a microbial high-throughput screening instrument based on elastic light scatter patterns

    PubMed Central

    Bae, Euiwon; Patsekin, Valery; Rajwa, Bartek; Bhunia, Arun K.; Holdman, Cheryl; Davisson, V. Jo; Hirleman, E. Daniel; Robinson, J. Paul

    2012-01-01

    A microbial high-throughput screening (HTS) system was developed that enabled high-speed combinatorial studies directly on bacterial colonies. The system consists of a forward scatterometer for elastic light scatter (ELS) detection, a plate transporter for sample handling, and a robotic incubator for automatic incubation. To minimize the ELS pattern-capturing time, a new calibration plate and correction algorithms were both designed, which dramatically reduced correction steps during acquisition of the circularly symmetric ELS patterns. Integration of three different control software programs was implemented, and the performance of the system was demonstrated with single-species detection for library generation and with time-resolved measurement for understanding ELS colony growth correlation, using Escherichia coli and Listeria. An in-house colony-tracking module enabled researchers to easily understand the time-dependent variation of the ELS from identical colony, which enabled further analysis in other biochemical experiments. The microbial HTS system provided an average scan time of 4.9 s per colony and the capability of automatically collecting more than 4000 ELS patterns within a 7-h time span. PMID:22559555

  8. Development of a microbial high-throughput screening instrument based on elastic light scatter patterns

    NASA Astrophysics Data System (ADS)

    Bae, Euiwon; Patsekin, Valery; Rajwa, Bartek; Bhunia, Arun K.; Holdman, Cheryl; Davisson, V. Jo; Hirleman, E. Daniel; Robinson, J. Paul

    2012-04-01

    A microbial high-throughput screening (HTS) system was developed that enabled high-speed combinatorial studies directly on bacterial colonies. The system consists of a forward scatterometer for elastic light scatter (ELS) detection, a plate transporter for sample handling, and a robotic incubator for automatic incubation. To minimize the ELS pattern-capturing time, a new calibration plate and correction algorithms were both designed, which dramatically reduced correction steps during acquisition of the circularly symmetric ELS patterns. Integration of three different control software programs was implemented, and the performance of the system was demonstrated with single-species detection for library generation and with time-resolved measurement for understanding ELS colony growth correlation, using Escherichia coli and Listeria. An in-house colony-tracking module enabled researchers to easily understand the time-dependent variation of the ELS from identical colony, which enabled further analysis in other biochemical experiments. The microbial HTS system provided an average scan time of 4.9 s per colony and the capability of automatically collecting more than 4000 ELS patterns within a 7-h time span.

  9. Changing Patterns of Cultural Imperialism in a Developing Country.

    ERIC Educational Resources Information Center

    Everitt, John

    Using Belize, Central America, as an example, this paper illustrates some of the changing patterns of cultural imperialism that can presently be viewed in the emerging nations of the world. Cultural imperialism is defined as the process whereby the culture of a weaker nation is dominated by that of a stronger nation. In September 1981, Belize,…

  10. Pattern Language Development in the Preparation of Inclusive Educators

    ERIC Educational Resources Information Center

    Bain, Alan; Lancaster, Julie; Zundans, Lucia

    2009-01-01

    Pattern language is the lexicon used to express the schema of a field of professional practice (Smethurst, 1997). This lexicon is frequently presumed to exist in communities of practice in educational settings, although the findings derived from the longitudinal study of schools (Elmore, 1996; Goodlad, 1984; Lortie, 1975; McLaughlin & Talbert,…

  11. Development of Instrumental Techniques for Color Assessment of Camouflage Patterns

    ERIC Educational Resources Information Center

    Fang, Gang

    2012-01-01

    Camouflage fabrics are produced on a large scale for use in the US military and other applications. One of the highest volume camouflage fabrics is known as the Universal Camouflage Pattern (UCP) which is produced for the US Department of Defense. At present, no standard measurement-based color quality control method exists for camouflage…

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

    NASA Astrophysics Data System (ADS)

    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

  13. Scientific and Technical Development of the Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Burg, Richard

    2003-01-01

    The Next Generation Space Telescope (NGST) is part of the Origins program and is the key mission to discover the origins of galaxies in the Universe. It is essential that scientific requirements be translated into technical specifications at the beginning of the program and that there is technical participation by astronomers in the design and modeling of the observatory. During the active time period of this grant, the PI participated in the NGST program at GSFC by participating in the development of the Design Reference Mission, the development of the full end-to-end model of the observatory, the design trade-off based on the modeling, the Science Instrument Module definition and modeling, the study of proto-mission and test-bed development, and by participating in meetings including quarterly reviews and support of the NGST SWG. This work was documented in a series of NGST Monographs that are available on the NGST web site.

  14. Photovoltaic power conditioners: Development, evolution, and the next generation

    SciTech Connect

    Bulawka, A.; Krauthamer, S.; Das, R.; Bower, W.

    1994-07-01

    Market-place acceptance of utility-connected photovoltaic (PV) power generation systems and their accelerated installation into residential and commercial applications are heavily dependent upon the ability of their power conditioning subsystems (PCS) to meet high reliability, low cost, and high performance goals. Many PCS development efforts have taken place over the last 15 years, and those efforts have resulted in substantial PCS hardware improvements. These improvements, however, have generally fallen short of meeting many reliability, cost and performance goals. Continuously evolving semiconductor technology developments, coupled with expanded market opportunities for power processing, offer a significant promise of improving PCS reliability, cost and performance, as they are integrated into future PCS designs. This paper revisits past and present development efforts in PCS design, identifies the evolutionary improvements and describes the new opportunities for PCS designs. The new opportunities are arising from the increased availability and capability of semiconductor switching components, smart power devices, and power integrated circuits (PICS).

  15. Fetal programming of infant neuromotor development: the generation R study.

    PubMed

    van Batenburg-Eddes, Tamara; de Groot, Laila; Steegers, Eric A P; Hofman, Albert; Jaddoe, Vincent W V; Verhulst, Frank C; Tiemeier, Henning

    2010-02-01

    The objective of the study was to examine whether infant neuromotor development is determined by fetal size and body symmetry in the general population. This study was embedded within the Generation R Study, a population-based cohort in Rotterdam. In 2965 fetuses, growth parameters were measured in mid-pregnancy and late pregnancy. After birth, at age 9 to 15 wks, neuromotor development was assessed with an adapted version of Touwen's Neurodevelopmental Examination. Less optimal neuromotor development was defined as a score in the highest tertile. We found that higher fetal weight was beneficial to infant neurodevelopment. A fetus with a 1-SD score higher weight in mid-pregnancy had an 11% lower risk of less optimal neuromotor development (OR: 0.89; 95% CI: 0.82-0.97). Similarly, a fetus with a 1-SD score larger abdominal-to-head circumference (AC/HC) ratio had a 13% lower risk of less optimal neuromotor development (OR: 0.87; 95% CI: 0.79-0.96). These associations were also present in late pregnancy. Our findings show that fetal size and body symmetry in pregnancy are associated with infant neuromotor development. These results suggest that differences in infant neuromotor development, a marker of behavioral and cognitive problems, are at least partly caused by processes occurring early in fetal life. PMID:19809381

  16. Applying Hilbert-Huang Transform to Develop a Novel Rainfall Generator

    NASA Astrophysics Data System (ADS)

    Li, Y.; Lien, W.; Tung, C.

    2013-12-01

    Climate change impacts on hydrology and water resources have drawn many attentions. More and more research have identified that not only human-induced climate change but also natural long-term trend should be also considered. The generation of rainfall is a useful tool for the management of water resources systems to climate change. Most of the generation models used previously only take into account daily and monthly variations in the model parameters. Some long-term patterns, such as decadal cycles or trends, are usually lost in the stochastic generation. The purpose of this study is to develop a novel rainfall generation. This research applies Hilbert-Huang Transform (HHT) to decompose the historical rainfall data into intrinsic mod functions (IMF) and trends. Each IMF represents a generally simple component of the rainfall time series. The generated base rainfall series, which is generated from the arranged historical rainfall series by stochastic simulation, is added to the trends and IMFs with more than one year periods derived from the result of HHT. Thus the newly simulated rainfall series with long-term properties is formed, and can be further applied to the impact of climate change on water resources management.

  17. Developement of 3D Vertically Integrated Pattern Recognition Associative Memory (VIPRAM)

    SciTech Connect

    Deputch, G.; Hoff, J.; Lipton, R.; Liu, T.; Olsen, J.; Ramberg, E.; Wu, Jin-Yuan; Yarema, R.; Shochet, M.; Tang, F.; Demarteau, M.; /Argonne /INFN, Padova

    2011-04-13

    Many next-generation physics experiments will be characterized by the collection of large quantities of data, taken in rapid succession, from which scientists will have to unravel the underlying physical processes. In most cases, large backgrounds will overwhelm the physics signal. Since the quantity of data that can be stored for later analysis is limited, real-time event selection is imperative to retain the interesting events while rejecting the background. Scaling of current technologies is unlikely to satisfy the scientific needs of future projects, so investments in transformational new technologies need to be made. For example, future particle physics experiments looking for rare processes will have to address the demanding challenges of fast pattern recognition in triggering as detector hit density becomes significantly higher due to the high luminosity required to produce the rare processes. In this proposal, we intend to develop hardware-based technology that significantly advances the state-of-the-art for fast pattern recognition within and outside HEP using the 3D vertical integration technology that has emerged recently in industry. The ultimate physics reach of the LHC experiments will crucially depend on the tracking trigger's ability to help discriminate between interesting rare events and the background. Hardware-based pattern recognition for fast triggering on particle tracks has been successfully used in high-energy physics experiments for some time. The CDF Silicon Vertex Trigger (SVT) at the Fermilab Tevatron is an excellent example. The method used there, developed in the 1990's, is based on algorithms that use a massively parallel associative memory architecture to identify patterns efficiently at high speed. However, due to much higher occupancy and event rates at the LHC, and the fact that the LHC detectors have a much larger number of channels in their tracking detectors, there is an enormous challenge in implementing pattern recognition

  18. Experiments evaluating subsidence generated within a subaqueous deformable substrate due to varying differential sediment loading patterns

    NASA Astrophysics Data System (ADS)

    Foreman, B.; Chatmas, E. S.; Abeyta, A.; Paola, C.

    2013-12-01

    The intraslope areas of many passive margins display a complex bathymetry of topographic depressions and crests that form series of minibasins. These minibasins are linked to the deformation of subsurface salt layers and act as localized sediment traps. Many mechanisms have been proposed for the initiation of minibasins, including tectonic forces (both extensional and contractional), regional gravitational sliding, density inversion between salt layers and overburden, and differential sediment loading. Regardless of initiation mechanism, it is widely recognized that synkinematic deposition plays a active role in determining subsidence patterns and sediment routing within and among the minibasins. We undertook a series of simplified 1-D and 2-D experiments 1) to evaluate the feasibility of developing a series of well-defined minibasins created exclusively by differential sediment loading and 2) to quantitatively determine the effects of substrate thickness, density contrast, and sedimentation rate on the resultant subsidence pattern. We also present an initial non-dimensionalized formulation of the problem that relates density contrasts, clinoform thickness, substrate thickness, progradation rate, and viscosity of the deformable substrate. Two sets of experiments were performed. The first set (1-D) vertically loaded a subaqueous corn syrup substrate (capturing the rheology of subsurface salt as a Newtonian fluid) with walnut sand. The second set (2-D) of experiments prograded a walnut sediment clinoform across a corn syrup substrate. We systematically varied sedimentation rate, substrate thickness, and, in the case of the prograding clinoform, base level. In no cases did we successfully reproduce a series of minibasins similar to those observed in natural settings. Instead the substrate was simply displaced laterally as sediment was deposited, forming a single depression. High sedimentation rates tended to produce wider zones of subsidence, however, if given

  19. Combustion Stability Analyses for J-2X Gas Generator Development

    NASA Technical Reports Server (NTRS)

    Hulka, J. R.; Protz, C. S.; Casiano, M. J.; Kenny, R. J.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) is developing a liquid oxygen/liquid hydrogen rocket engine for upper stage and trans-lunar applications of the Ares vehicles for the Constellation program. This engine, designated the J-2X, is a higher pressure, higher thrust variant of the Apollo-era J-2 engine. Development was contracted to Pratt & Whitney Rocketdyne in 2006. Over the past several years, development of the gas generator for the J-2X engine has progressed through a variety of workhorse injector, chamber, and feed system configurations. Several of these configurations have resulted in injection-coupled combustion instability of the gas generator assembly at the first longitudinal mode of the combustion chamber. In this paper, the longitudinal mode combustion instabilities observed on the workhorse test stand are discussed in detail. Aspects of this combustion instability have been modeled at the NASA Marshall Space Flight Center with several codes, including the Rocket Combustor Interaction Design and Analysis (ROCCID) code and a new lumped-parameter MatLab model. To accurately predict the instability characteristics of all the chamber and injector geometries and test conditions, several features of the submodels in the ROCCID suite of calculations required modification. Finite-element analyses were conducted of several complicated combustion chamber geometries to determine how to model and anchor the chamber response in ROCCID. A large suite of sensitivity calculations were conducted to determine how to model and anchor the injector response in ROCCID. These modifications and their ramification for future stability analyses of this type are discussed in detail. The lumped-parameter MatLab model of the gas generator assembly was created as an alternative calculation to the ROCCID methodology. This paper also describes this model and the stability calculations.

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

    PubMed

    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.

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

    PubMed

    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

  2. Airframe Technology Development for Next Generation Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Glass, David E.

    2004-01-01

    The Airframe subproject within NASA's Next Generation Launch Technology (NGLT) program has the responsibility to develop airframe technology for both rocket and airbreathing vehicles for access to space. The Airframe sub-project pushes the state-of-the-art in airframe technology for low-cost, reliable, and safe space transportation. Both low and medium technology readiness level (TRL) activities are being pursued. The key technical areas being addressed include design and integration, hot and integrated structures, cryogenic tanks, and thermal protection systems. Each of the technologies in these areas are discussed in this paper.

  3. Participatory Design in Open Education: A Workshop Model for Developing a Pattern Language

    ERIC Educational Resources Information Center

    Mor, Yishay; Winters, Niall

    2008-01-01

    Technologically enhanced learning environments raise complex challenges for their designers, developers and users. Design patterns and pattern languages have recently emerged as a potential framework for addressing some of these challenges. However, the uptake of design patterns has been slow outside of the computer science community. We argue…

  4. Integration and optimization of the DUV ALTA pattern generation system using a CAR process with the Tetra photomask etch system

    NASA Astrophysics Data System (ADS)

    Buxbaum, Alex H.; Fuller, Scott E.; Montgomery, Warren; Ungureit, Michael E.

    2003-12-01

    Etec Systems, the Mask Business Group of Applied Materials, is in a unique position within the mask making industry - Etec has the opportunity to integrate individual parts of the overall mask manufacturing process to provide a more complete solution. Here we present the integration of the DUV ALTA laser pattern generator and the TetraTM photomask etch system with advanced CAR resist processes. Dry etch process effects of flow, overetch, and oxygen content (in a Cl2/O2/He plasma) are discussed for the baseline POR resist in terms of etch rate, selectivity, etch bias, CD uniformity and micro-loading; the optimized etch process space was then implemented for advanced CAR resists. Iso-dense bias, football pattern loading and other pattern transfer results influencing mask manufactureability are also presented. Within the synthesis and optimization of the pattern generation system, process, and dry etch sub 13 nm range process uniformity has been achieved. The integrated ALTA / Tetra / Advanced-CAR solution set is characterized on both Etec test patterns and customer demonstrations.

  5. Development of a Text Summarization System Using Verb-based Sentence Patterns.

    ERIC Educational Resources Information Center

    Choe, In-Sook; Chung, Young-Mee

    2001-01-01

    Presents a text summarization system and examines its validity by comparing automatically generated summaries with human-generated ones. Examines the accuracy of the system by evaluating the representativeness of cue verbs and basic sentence patterns, as well as the essential information in a summary. Also analyzes syntactic and semantic errors of…

  6. Stirling Convertor Technologies Being Developed for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.

    2003-01-01

    The Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and the NASA Glenn Research Center are developing a high-efficiency Stirling Radioisotope Generator (SRG) for NASA space science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. On Mars, rovers with SRGs would be used for missions that might not be able to use photovoltaic power systems, such as exploration at high Martian latitudes and missions of long duration. The projected SRG system efficiency of 23 percent will reduce the required amount of radioisotope by a factor of 4 or more in comparison to currently used Radioisotope Thermoelectric Generators. The Department of Energy recently named Lockheed Martin as the system integration contractor. Lockheed Martin has begun to develop the SRG engineering unit under contract to the Department of Energy, and has contract options to develop the qualification unit and the first flight units. The developers expect the SRG to produce about 114 Wdc at the beginning of mission, using two opposed Stirling convertors and two General Purpose Heat Source modules. STC previously developed the Stirling convertor under contract to the Department of Energy and is now providing further development as a subcontractor to Lockheed Martin. Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. A key milestone was recently reached with the accumulation of 12 000 hr of long-term aging on two types of neodymium-iron boron permanent magnets. These tests are characterizing any possible aging in the strength or demagnetization resistance of the magnets used in the linear alternator. Preparations are underway for a thermal/vacuum system demonstration and unattended operation during endurance testing of the 55-We Technology Demonstration Convertors. In addition, Glenn is developing a

  7. A method to integrate patterned electrospun fibers with microfluidic systems to generate complex microenvironments for cell culture applications

    PubMed Central

    Wallin, Patric; Zandén, Carl; Carlberg, Björn; Hellström Erkenstam, Nina; Liu, Johan; Gold, Julie

    2012-01-01

    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

  8. Spongiosa Primary Development: A Biochemical Hypothesis by Turing Patterns Formations

    PubMed Central

    López-Vaca, Oscar Rodrigo; Garzón-Alvarado, Diego Alexander

    2012-01-01

    We propose a biochemical model describing the formation of primary spongiosa architecture through a bioregulatory model by metalloproteinase 13 (MMP13) and vascular endothelial growth factor (VEGF). It is assumed that MMP13 regulates cartilage degradation and the VEGF allows vascularization and advances in the ossification front through the presence of osteoblasts. The coupling of this set of molecules is represented by reaction-diffusion equations with parameters in the Turing space, creating a stable spatiotemporal pattern that leads to the formation of the trabeculae present in the spongy tissue. Experimental evidence has shown that the MMP13 regulates VEGF formation, and it is assumed that VEGF negatively regulates MMP13 formation. Thus, the patterns obtained by ossification may represent the primary spongiosa formation during endochondral ossification. Moreover, for the numerical solution, we used the finite element method with the Newton-Raphson method to approximate partial differential nonlinear equations. Ossification patterns obtained may represent the primary spongiosa formation during endochondral ossification. PMID:23193429

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

    PubMed

    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

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

    PubMed Central

    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. Thin film passivation of laser generated 3D micro patterns in lithium manganese oxide cathodes

    NASA Astrophysics Data System (ADS)

    Pröll, J.; Kohler, R.; Bruns, M.; Oberst, V.; Weidler, P. G.; Heißler, S.; Kübel, C.; Scherer, T.; Prang, R.; Seifert, H. J.; Pfleging, W.

    2013-03-01

    The increasing need for long-life lithium-ion batteries requires the further development of electrode materials. Especially on the cathode side new materials or material composites are needed to increase the cycle lifetime. On the one hand, spinel-type lithium manganese oxide is a promising candidate to be used as cathode material due to its non-toxicity, low cost and good thermal stability. On the other hand, the spinel structure suffers from change in the oxidation state of manganese during cycling which is also accompanied by loss of active material into the liquid electrolyte. The general trend is to enhance the active surface area of the cathode in order to increase lithium-ion mobility through the electrode/electrolyte interface, while an enhanced surface area will also promote chemical degradation. In this work, laser microstructuring of lithium manganese oxide thin films was applied in a first step to increase the active surface area. This was done by using 248 nm excimer laser radiation and chromium/quartz mask imaging techniques. In a second step, high power diode laser-annealing operating at a wavelength of 940 nm was used for forming a cubic spinel-like battery phase. This was verified by means of Raman spectroscopy and cyclic voltammetric measurements. In a last step, the laser patterned thin films were coated with indium tin oxide (ITO) layers with a thickness of 10 nm to 50 nm. The influence of the 3D surface topography as well as the ITO thickness on the electrochemical performance was studied by cyclic voltammetry. Post-mortem studies were carried out by using scanning electron microscopy and focused ion beam analysis.

  12. Joint Development of a Fourth Generation Single Crystal Superalloy

    NASA Technical Reports Server (NTRS)

    Walston, S.; Cetel, A.; MacKay, R.; OHara, K.; Duhl, D.; Dreshfield, R.

    2004-01-01

    A new, fourth generation, single crystal superalloy has been jointly developed by GE Aircraft Engines, Pratt & Whitney, and NASA. The focus of the effort was to develop a turbine airfoil alloy with long-term durability for use in the High Speed Civil Transport. In order to achieve adequate long-time strength improvements at moderate temperatures and retain good microstructural stability, it was necessary to make significant composition changes from 2nd and 3rd generation single crystal superalloys. These included lower chromium levels, higher cobalt and rhenium levels and the inclusion of a new alloying element, ruthenium. It was found that higher Co levels were beneficial to reducing both TCP precipitation and SRZ formation. Ruthenium caused the refractory elements to partition more strongly to the ' phase, which resulted in better overall alloy stability. The final alloy, EPM 102, had significant creep rupture and fatigue improvements over the baseline production alloys and had acceptable microstructural stability. The alloy is currently being engine tested and evaluated for advanced engine applications.

  13. Next-generation digital camera integration and software development issues

    NASA Astrophysics Data System (ADS)

    Venkataraman, Shyam; Peters, Ken; Hecht, Richard

    1998-04-01

    This paper investigates the complexities associated with the development of next generation digital cameras due to requirements in connectivity and interoperability. Each successive generation of digital camera improves drastically in cost, performance, resolution, image quality and interoperability features. This is being accomplished by advancements in a number of areas: research, silicon, standards, etc. As the capabilities of these cameras increase, so do the requirements for both hardware and software. Today, there are two single chip camera solutions in the market including the Motorola MPC 823 and LSI DCAM- 101. Real time constraints for a digital camera may be defined by the maximum time allowable between capture of images. Constraints in the design of an embedded digital camera include processor architecture, memory, processing speed and the real-time operating systems. This paper will present the LSI DCAM-101, a single-chip digital camera solution. It will present an overview of the architecture and the challenges in hardware and software for supporting streaming video in such a complex device. Issues presented include the development of the data flow software architecture, testing and integration on this complex silicon device. The strategy for optimizing performance on the architecture will also be presented.

  14. Maize transformation technology development for commercial event generation

    PubMed Central

    Que, Qiudeng; Elumalai, Sivamani; Li, Xianggan; Zhong, Heng; Nalapalli, Samson; Schweiner, Michael; Fei, Xiaoyin; Nuccio, Michael; Kelliher, Timothy; Gu, Weining; Chen, Zhongying; Chilton, Mary-Dell M.

    2014-01-01

    Maize is an important food and feed crop in many countries. It is also one of the most important target crops for the application of biotechnology. Currently, there are more biotech traits available on the market in maize than in any other crop. Generation of transgenic events is a crucial step in the development of biotech traits. For commercial applications, a high throughput transformation system producing a large number of high quality events in an elite genetic background is highly desirable. There has been tremendous progress in Agrobacterium-mediated maize transformation since the publication of the Ishida et al. (1996) paper and the technology has been widely adopted for transgenic event production by many labs around the world. We will review general efforts in establishing efficient maize transformation technologies useful for transgenic event production in trait research and development. The review will also discuss transformation systems used for generating commercial maize trait events currently on the market. As the number of traits is increasing steadily and two or more modes of action are used to control key pests, new tools are needed to efficiently transform vectors containing multiple trait genes. We will review general guidelines for assembling binary vectors for commercial transformation. Approaches to increase transformation efficiency and gene expression of large gene stack vectors will be discussed. Finally, recent studies of targeted genome modification and transgene insertion using different site-directed nuclease technologies will be reviewed. PMID:25140170

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

    NASA Astrophysics Data System (ADS)

    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

  16. Shared rules of development predict patterns of evolution in vertebrate segmentation.

    PubMed

    Young, Nathan M; Winslow, Benjamin; Takkellapati, Sowmya; Kavanagh, Kathryn

    2015-04-01

    Phenotypic diversity is not uniformly distributed, but how biased patterns of evolutionary variation are generated and whether common developmental mechanisms are responsible remains debatable. High-level 'rules' of self-organization and assembly are increasingly used to model organismal development, even when the underlying cellular or molecular players are unknown. One such rule, the inhibitory cascade, predicts that proportions of segmental series derive from the relative strengths of activating and inhibitory interactions acting on both local and global scales. Here we show that this developmental design rule explains population-level variation in segment proportions, their response to artificial selection and experimental blockade of putative signals and macroevolutionary diversity in limbs, digits and somites. Together with evidence from teeth, these results indicate that segmentation across independent developmental modules shares a common regulatory 'logic', which has a predictable impact on both their short and long-term evolvability.

  17. Shared rules of development predict patterns of evolution in vertebrate segmentation.

    PubMed

    Young, Nathan M; Winslow, Benjamin; Takkellapati, Sowmya; Kavanagh, Kathryn

    2015-01-01

    Phenotypic diversity is not uniformly distributed, but how biased patterns of evolutionary variation are generated and whether common developmental mechanisms are responsible remains debatable. High-level 'rules' of self-organization and assembly are increasingly used to model organismal development, even when the underlying cellular or molecular players are unknown. One such rule, the inhibitory cascade, predicts that proportions of segmental series derive from the relative strengths of activating and inhibitory interactions acting on both local and global scales. Here we show that this developmental design rule explains population-level variation in segment proportions, their response to artificial selection and experimental blockade of putative signals and macroevolutionary diversity in limbs, digits and somites. Together with evidence from teeth, these results indicate that segmentation across independent developmental modules shares a common regulatory 'logic', which has a predictable impact on both their short and long-term evolvability. PMID:25827599

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

    ERIC Educational Resources Information Center

    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…

  19. Fasciola hepatica: development of redial generations in experimental infections of Pseudosuccinea columella.

    PubMed

    Dar, Y; Rondelaud, D; Vignoles, P; Dreyfuss, G

    2014-07-01

    Experimental infections of Egyptian Pseudosuccinea columella with one or two miracidia of Fasciola hepatica per snail were carried out to determine the developmental pattern (normal or abnormal) of redial generations and specify the number of free rediae developing in snails according to their generation. Controls were constituted by a French population of Galba truncatula infected according to the same protocol. Most infected P. columella showed a normal development of redial generations (96.2-98.1 vs 75.5-85.7% for G. truncatula). In each redial category, free rediae were more numerous in P. columella than in G. truncatula, and their number were also greater in the two-miracidia groups than in single-miracidium infections for each lymnaeid considered separately. This increase in redial production was mainly due to the number of first mother (R1a) rediae producing daughter rediae only: 2 per P. columella (vs one redia in G. truncatula) in single-miracidium groups and 3.1 (vs 1.9) in the two-miracidia groups. In P. columella, the mean total number of free rediae developing in single-miracidium and bimiracidial infections was 77.2 and 117.6, respectively (instead of 33.5 and 52.1 rediae in G. truncatula). The number of F. hepatica rediae present in P. columella was related to the number of fully grown sporocysts and the quantity of R1a rediae which developed into the snail body. PMID:24832813

  20. Self-organization of repetitive spike patterns in developing neuronal networks in vitro.

    PubMed

    Sun, Jyh-Jang; Kilb, Werner; Luhmann, Heiko J

    2010-10-01

    The appearance of spontaneous correlated activity is a fundamental feature of developing neuronal networks in vivo and in vitro. To elucidate whether the ontogeny of correlated activity is paralleled by the appearance of specific spike patterns we used a template-matching algorithm to detect repetitive spike patterns in multi-electrode array recordings from cultures of dissociated mouse neocortical neurons between 6 and 15 days in vitro (div). These experiments demonstrated that the number of spiking neurons increased significantly between 6 and 15 div, while a significantly synchronized network activity appeared at 9 div and became the main discharge pattern in the subsequent div. Repetitive spike patterns with a low complexity were first observed at 8 div. The number of repetitive spike patterns in each dataset as well as their complexity and recurrence increased during development in vitro. The number of links between neurons implicated in repetitive spike patterns, as well as their strength, showed a gradual increase during development. About 8% of the spike sequences contributed to more than one repetitive spike patterns and were classified as core patterns. These results demonstrate for the first time that defined neuronal assemblies, as represented by repetitive spike patterns, appear quite early during development in vitro, around the time synchronized network burst become the dominant network pattern. In summary, these findings suggest that dissociated neurons can self-organize into complex neuronal networks that allow reliable flow and processing of neuronal information already during early phases of development.

  1. Development of a new generation of small scale biomass-fueled electric generating power plants

    SciTech Connect

    Craig, J.D.; Purvis, C.R.

    1995-11-01

    There exists a need by a large worldwide market for greatly improved small scale (1 to 20 MWe per unit) biomass-fueled power plants. These power plants will significantly increase the efficiency of generating electric power from wood and bagasse as well as convert non-traditional fuel sources such as rice hulls, animal manure, cotton gin trash, straws, and grasses to electricity. Advancing the technology of biomass-fueled power plants will greatly expand the use of this environmentally friendly sustainable 24 hr-per-day source of electrical power for industry and communities worldwide. This paper briefly describes the status of a biomass-fueled power plant under development by Cratech, Inc.

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

    PubMed

    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

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

    PubMed

    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.

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

    PubMed Central

    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

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

    PubMed

    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. A simple model for polar cap convection patterns and generation of theta auroras

    NASA Technical Reports Server (NTRS)

    Lyons, L. R.

    1985-01-01

    An addition of the uniform interplanetary magnetic field and the earth's dipole magnetic field is used to evaluate electric field convection patterns over the polar caps that result from solar wind flow across open geomagnetic field lines. The model also accounts for field-aligned patterns within, and auroral arcs across, the polar cap. The qualitative predictions derived from the model express the electric field magnitudes, aurora intensity, sunward and antisunward flow, and the dusk-side reversal of the convection field in terms of the x and y components of the interplanetary magnetic field.

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

    PubMed

    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. PMID:26627818

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

    PubMed

    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

  9. Manipulation of micro-particles through optical interference patterns generated by integrated photonic devices.

    PubMed

    Hsu, Li-Chung; Chen, Te-Chang; Yang, Yao-Tsu; Huang, Chieh-Yang; Shen, Da-Wei; Chen, Ya-Tzu; Lee, Ming-Chang M

    2013-03-21

    Micro-particle transport and switch governed by guided-wave optical interference are presented. The optical interference, occurring in a directional coupler and a multi-mode interferometer made by inverted rib waveguides, results in a specific evanescent field dependent on wavelength. Through a detailed theoretical analysis, the field of induced optical force shows a correlative pattern associated with the evanescent field. Experimental results demonstrate that 10 μm polystyrene beads are propelled with a trajectory subject to the interference pattern accordingly. By launching different wavelengths, the polystyrene beads can be delivered to different output waveguide ports. Massive micro-particle manipulation is applicable.

  10. Generation of nano-scaled DNA patterns through electro-beam induced charge trapping

    NASA Astrophysics Data System (ADS)

    Chi, Pei-Yin; Lin, Hung-Yi; Liu, Cheng-Hsien; Chen, Chii-Dong

    2006-10-01

    In this study, distinct regions of trapped charges on glass substrates created by electron beam bombardment were utilized to attract and to immobilize DNA molecules. The negatively charged DNA molecules were attracted by the positive charge layer beneath the substrate surface resulting from escape of secondary electrons. With this mechanism, we demonstrated high-precision patterning of unmodified DNA molecules, independent of the length, sequence, and number of DNA strands, and with an attachment to the glass surface strong enough to withstand vigorous washing with water. DNA patterns with the line width of 50 nm were achieved.

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

    PubMed

    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.

  12. Development of rf plasma generators for neutral beams

    SciTech Connect

    Vella, M.C.; Ehlers, K.W.; Kippenhan, D.; Pincosy, P.A.; Pyle, R.V.; DiVergilio, W.F.; Fosnight, V.V.

    1984-10-01

    The development of low frequency (1-2 MHz) rf plasma generators for high power neutral beam applications is summarized. Immersed couplers from one to three turns were used. Acceptable plasma profiles, less than or equal to 15% max/min, were obtained in a variety of field-free magnetic bucket and magnetic filter-bucket sources, with 10 x 10 cm or 10 x 40 cm extraction areas. Hydrogen beam properties were measured with a 7 x 10 cm accelerator operated at 80 kV. Atomic fraction and power efficiency were at least as high as with arc plasmas in similar chambers. The potential advantages of an rf plasma source are: ease of operation; reliability; and extended service lifetime.

  13. Development of second generation EP2 antagonists with high selectivity

    PubMed Central

    Ganesh, Thota; Jiang, Jianxiong; Dingledine, Ray

    2014-01-01

    EP2 receptor has emerged as an important biological target for therapeutic intervention. In particular, it has been shown to exacerbate disease progression of a variety of CNS and peripheral diseases. Deletion of the EP2 receptor in mouse models recapitulates several features of the COX-2 inhibition, thus presenting a new avenue for anti-inflammatory therapy which could bypass some of the adverse side effects observed by the COX-2 inhibition therapy. We have recently reported a cinnamic amide class of EP2 antagonists with high potency, but these compounds exhibited a moderate selectivity against prostanoid receptor DP1. Moreover they possess acrylamide moiety in the structure, which may result in liver toxicity over longer period of use in a chronic disease model. Thus, we now developed a second generation compounds that devoid of the acrylamide functionality and possess high potency and improved (>1000-fold) selectivity to EP2 over other prostanoid receptors. PMID:24937185

  14. Further developments in generating type-safe messaging

    SciTech Connect

    Neswold, R.; King, C.; /Fermilab

    2011-11-01

    At ICALEPCS 09, we introduced a source code generator that allows processes to communicate safely using data types native to each host language. In this paper, we discuss further development that has occurred since the conference in Kobe, Japan, including the addition of three more client languages, an optimization in network packet size and the addition of a new protocol data type. The protocol compiler is continuing to prove itself as an easy and robust way to get applications written in different languages hosted on different computer architectures to communicate. We have two active Erlang projects that are using the protocol compiler to access ACNET data at high data rates. We also used the protocol compiler output to deliver ACNET data to an iPhone/iPad application. Since it takes an average of two weeks to support a new language, we're willing to expand the protocol compiler to support new languages that our community uses.

  15. Development of vanadium redox flow battery for photovoltaic generation system

    SciTech Connect

    Shibata, Akira; Sato, Kanji; Nakajima, Masato

    1994-12-31

    Photovoltaic power generation system (PV) requires a battery for night and rainy day. A redox flow battery has advantage over a lead acid one on this application for the capability of deep discharge and needlessness of equalized charge. The authors have developed the high performance vanadium redox flow battery for this purpose and inexpensive production technology of electrolyte which occupies the majority in the battery cost by chemical reduction from boiler plant by-product. The 2 kW (10 kWh) battery, the minimum unit for practical size battery (50 kW x 50 h), achieved 1.2 kW/cm{sup 2}-electrode area at the 100 mA/cm{sup 2} current density.

  16. Development of rf plasma generators for neutral beams

    SciTech Connect

    Vella, M.C.; Ehlers, K.W.; Kippenhan, D.; Pincosy, P.A.; Pyle, R.V.; DiVergilio, W.F.; Fosnight, V.V.

    1985-05-01

    The development of low frequency (1--2 MHz) rf plasma generators for high power neutral beam applications is summarized. Immersed couplers from one to three turns were used. Acceptable plasma profiles, < or =15% max/min, were obtained in a variety of field-free, magnetic bucket and magnetic filter-bucket sources, with 10 x 10 or 10 x 40 cm extraction areas. Hydrogen beam properties were measured with a 7 x 10 cm accelerator operated at 80 kV. Atomic fraction and power efficiency were at least as high as with arc plasmas in similar chambers. The potential advantages of an rf plasma source are: ease of operation; reliability; and extended service lifetime.

  17. Developing a cloud mask climatology covering two Meteosat satellite generations

    NASA Astrophysics Data System (ADS)

    Posselt, Rebekka; Stöckli, Reto; Liniger, Mark A.

    2013-04-01

    Long term cloud cover observations from satellites are fundamental for climate model validation and climate monitoring. Further, they support ground-based observations in regions with sparse coverage. Additionally, information on cloud cover is needed to derive other physical parameters such as surface radiation fluxes or clear sky and cloudy atmospheric states and is of high relevance for the solar energy sector. Within the current project phase of the Satellite Application Facility on Climate Monitoring (CM SAF) an algorithm to calculate a climatological cloud mask (or cloud cover probability) from Meteosat satellites is developed. The algorithm shall be applicable for both Meteosat first generation (1983-2005) and Meteosat second generation (2004-present) which significantly differ in their spectral properties. The algorithm linearly aggregates a set of continuous scores instead of the commonly used decision tree approach. The scores are calculated for different channels as well as different spatial and temporal settings. Each score yields a probability for the pixel's cloud cover. The final result, the cloud cover probability, is obtained by combining all available scores taking into account the varying performance of the scores during day and night and over snow. The uncertainty of the final cloud cover estimate is an inherent part of the probability. The algorithm is calibrated using cloud cover measurements from SYNOP stations located on the Meteosat disc. The subsequent validation is done at an independent set of collocated SYNOP/ARSA (Automated Radiosonde Archive) stations. The presentation introduces the applied cloud mask algorithm and presents the results of the validation for both satellite generations. The comparison of the two satellite generations addresses the climatological homogeneity of the future cloud mask climate data record which will be distributed by CM SAF after 2016. Special attention is also drawn to issues like the day-night-bias of

  18. Developing the Next Generation Shell Buckling Design Factors and Technologies

    NASA Technical Reports Server (NTRS)

    Hilburger, Mark W.

    2012-01-01

    NASA s Shell Buckling Knockdown Factor (SBKF) Project was established in the spring of 2007 by the NASA Engineering and Safety Center (NESC) in collaboration with the Constellation Program and Exploration Systems Mission Directorate. The SBKF project has the current goal of developing less-conservative, robust shell buckling design factors (a.k.a. knockdown factors) and design and analysis technologies for light-weight stiffened metallic launch vehicle (LV) structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and mass-growth in these vehicles and can help mitigate some of NASA s LV development and performance risks. In particular, it is expected that the results from this project will help reduce the reliance on testing, provide high-fidelity estimates of structural performance, reliability, robustness, and enable increased payload capability. The SBKF project objectives and approach used to develop and validate new design technologies are presented, and provide a glimpse into the future of design of the next generation of buckling-critical launch vehicle structures.

  19. Dendritic development of newly generated neurons in the adult brain.

    PubMed

    Ribak, Charles E; Shapiro, Lee A

    2007-10-01

    Ramon y Cajal described the fundamental morphology of the dendritic and axonal growth cones of neurons during development. However, technical limitations at the time prevented him from describing such growth cones from newborn neurons in the adult brain. The phenomenon of adult neurogenesis is briefly reviewed, and the structural description of dendritic and axonal outgrowth for these newly generated neurons in the adult brain is discussed. Axonal outgrowth into the hilus and CA3 region of the hippocampus occurs later than the outgrowth of dendrites into the molecular layer, and the ultrastructural analysis of axonal outgrowth has yet to be completed. In contrast, growth cones on dendrites from newborn neurons in the adult dentate gyrus have been described and this observation suggests that dendrites in adult brains grow in a similar way to those found in immature brains. However, dendrites in adult brains have to navigate through a denser neuropil and a more complex cell layer. Therefore, some aspects of dendritic outgrowth of neurons born in the adult dentate gyrus are different as compared to that found in development. These differences include the radial process of radial glial cells acting as a lattice to guide apical dendritic growth through the granule cell layer and a much thinner dendrite to grow through the neuropil of the molecular layer. Therefore, similarities and differences exist for dendritic outgrowth from newborn neurons in the developing and adult brain.

  20. Cultural and environmental influences on temporal-spectral development patterns of corn and soybeans

    NASA Technical Reports Server (NTRS)

    Crist, E. P.

    1982-01-01

    A technique for evaluating crop temporal-spectral development patterns is described and applied to the analysis of cropping practices and environmental conditions as they affect reflectance characteristics of corn and soybean canopies. Typical variations in field conditions are shown to exert significant influences on the spectral development patterns, and thereby to affect the separability of the two crops.

  1. The 2nd Generation Real Time Mission Monitor (RTMM) Development

    NASA Technical Reports Server (NTRS)

    Blakeslee, Richard; Goodman, Michael; Meyer, Paul; Hardin, Danny; Hall, John; He, Yubin; Regner, Kathryn; Conover, Helen; Smith, Tammy; Lu, Jessica; Garrett, Michelle

    2009-01-01

    The NASA Real Time Mission Monitor (RTMM) is a visualization and information system that fuses multiple Earth science data sources, to enable real time decisionmaking for airborne and ground validation experiments. Developed at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center, RTMM is a situational awareness, decision-support system that integrates satellite imagery and orbit data, radar and other surface observations (e.g., lightning location network data), airborne navigation and instrument data sets, model output parameters, and other applicable Earth science data sets. The integration and delivery of this information is made possible using data acquisition systems, network communication links, network server resources, and visualizations through the Google Earth virtual globe application. In order to improve the usefulness and efficiency of the RTMM system, capabilities are being developed to allow the end-user to easily configure RTMM applications based on their mission-specific requirements and objectives. This second generation RTMM is being redesigned to take advantage of the Google plug-in capabilities to run multiple applications in a web browser rather than the original single application Google Earth approach. Currently RTMM employs a limited Service Oriented Architecture approach to enable discovery of mission specific resources. We are expanding the RTMM architecture such that it will more effectively utilize the Open Geospatial Consortium Sensor Web Enablement services and other new technology software tools and components. These modifications and extensions will result in a robust, versatile RTMM system that will greatly increase flexibility of the user to choose which science data sets and support applications to view and/or use. The improvements brought about by RTMM 2nd generation system will provide mission planners and airborne scientists with enhanced decision-making tools and capabilities to more

  2. Unique expression patterns of cell fate molecules delineate sequential stages of dentate gyrus development.

    PubMed

    Pleasure, S J; Collins, A E; Lowenstein, D H

    2000-08-15

    The dentate gyrus of the hippocampus is uniquely organized with a displaced proliferative zone that continues to generate dentate granule cells throughout life. We have analyzed the expression of Notch receptors, Notch ligands, and basic helix-loop-helix (bHLH) genes during dentate gyrus development to determine whether the need to maintain a pool of undifferentiated precursors is reflected in the patterns of expression of these genes. Many of these genes are expressed diffusely throughout the cortical neuroepithelium at embryonic days 16 and 17 in the rat, just preceding the migration of newly born granule cells and dentate precursor cells into the dentate anlage. However, at this time, Mash1, Math3, and Id3 expression are all concentrated in the area that specifically gives rise to granule cells and dentate precursor cells. Two days later, at the time of migration of the first granule cells and dentate precursor cells, cells expressing Mash1 are seen in the migratory route from the subventricular zone to the developing dentate gyrus. Newly born granule cells expressing NeuroD are also present in this migratory pathway. In the first postnatal week, precursor cells expressing Mash1 reside in the dentate hilus, and by the third postnatal week they have largely taken up their final position in the subgranular zone along the hilar side of the dentate granule cell layer. After terminal differentiation, granule cells born in the hilus or the subgranular zone begin to express NeuroD followed by NeuroD2. This study establishes that the expression patterns of bHLH mRNAs evolve during the formation of the dentate gyrus, and the precursor cells resident in the mature dentate gyrus share features with precursor cells found in development. Thus, many of the same mechanisms that are known to regulate cell fate and precursor pool size in other brain regions are likely to be operative in the dentate gyrus at all stages of development.

  3. [Pattern of replaceability of generations among inhabitants of Bejsce parish, Kielce voivodship (eighteenth to twentieth centuries)].

    PubMed

    Piasecki, E

    1983-01-01

    A review of population dynamics in the Polish parish of Bejsce, in Kielce voivodship, from the eighteenth to the twentieth centuries is presented. The study is based on data from computerized parish records. Its focus is on changes in fertility and the pattern of human reproduction over time and on the factors affecting these changes. (summary in ENG)

  4. Information-generated Influence as a Function of Locus-of-Control Patterns in Children

    ERIC Educational Resources Information Center

    Wolk, Stephen; Eliot, John

    1974-01-01

    Investigated the degree to which an individual disregards information about himself and his environment, as a function of his locus of control patterns, and hence is less responsive to or influenced by a given segment of information. Subjects were 341 fourth- and fifth-grade children. (SDH)

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

    NASA Astrophysics Data System (ADS)

    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

  6. Changing patterns of migration in Latin America: how can research develop intelligence for public health?

    PubMed

    Cabieses, Baltica; Tunstall, Helena; Pickett, Kate E; Gideon, Jasmine

    2013-07-01

    Migration patterns in Latin America have changed significantly in recent decades, particularly since the onset of global recession in 2007. These recent economic changes have highlighted and exacerbated the weakness of evidence from Latin America regarding migration-a crucial determinant of health. Migration patterns are constantly evolving in Latin America, but research on migration has not developed at the same speed. This article focuses on the need for better understanding of the living conditions and health of migrant populations in Latin America within the context of the recent global recession. The authors explain how new data on migrant well-being could be obtained through improved evidence from censuses and ongoing research surveys to 1) better inform policy-makers about the needs of migrant populations in Latin America and 2) help determine better ways of reaching undocumented immigrants. Longitudinal studies on immigrants in Latin America are essential for generating a better representation of migrant living conditions and health needs during the initial stages of immigration and over time. To help meet this need, the authors support the promotion of sustainable sources of data and evidence on the complex relationship between migration and health.

  7. [Determination of type and spatial pattern formation of flower organs: dynamic model of development].

    PubMed

    Skriabin, K G; Alekseev, D V; Ezhova, T A; Kozlov, V N; Kudriavtsev, V B; Nosov, M V; Penin, A A; Chub, V V; Shestakov, S V; Shul'ga, O A

    2006-01-01

    The mathematical model imitating floral organ spatial pattern formation (positioning) was developed. Computer experiments performed on its basis demonstrated that organ spatial pattern formation in typical crucifer flower occurred in successive order: medial sepals, carpels, lateral sepals, long stamens, petals and short stamens. The positioning was advanced in two directions, acropetally in the perianth and basipetally in the stamens and carpels. The organ type specifying and positioning take place non-simultaneously in different floral areas. The organ type specifying passed ahead of organ primordial spatial pattern formation. The modeling of flower development of several mutants demonstrated that arabidopsis genes AP2 and AG in addition to specifying floral organ types also determine the particular zones in the floral meristem for futur organ development. The AG gene controls the formation of basipetal patterning zones where the reproductive organs develop, AP2 maintains the proliferative activity in the floral meristem that form acropetal patterning zones where perianth organ develop.

  8. Branching patterns emerge in a mathematical model of the dynamics of lung development

    PubMed Central

    Guo, Yina; Chen, Ting-Hsuan; Zeng, Xingjuan; Warburton, David; Boström, Kristina I; Ho, Chih-Ming; Zhao, Xin; Garfinkel, Alan

    2014-01-01

    Recent experimental work has described an elegant pattern of branching in the development of the lung. Multiple forms of branching have been identified, including side branching and tip bifurcation. A particularly interesting feature is the phenomenon of ‘orthogonal rotation of the branching plane’. The lung must fill 3D space with the essentially 2D phenomenon of branching. It accomplishes this by rotating the branching plane by 90° with each generation. The mechanisms underlying this rotation are not understood. In general, the programmes that underlie branching have been hypothetically attributed to genetic ‘subroutines’ under the control of a ‘global master routine’ to invoke particular subroutines at the proper time and location, but the mechanisms of these routines are not known. Here, we demonstrate that fundamental mechanisms, the reaction and diffusion of biochemical morphogens, can create these patterns. We used a partial differential equation model that postulates three morphogens, which we identify with specific molecules in lung development. We found that cascades of branching events, including side branching, tip splitting and orthogonal rotation of the branching plane, all emerge immediately from the model, without further assumptions. In addition, we found that one branching mode can be easily switched to another, by increasing or decreasing the values of key parameters. This shows how a ‘global master routine’ could work by the alteration of a single parameter. Being able to simulate cascades of branching events is necessary to understand the critical features of branching, such as orthogonal rotation of the branching plane between successive generations, and branching mode switch during lung development. Thus, our model provides a paradigm for how genes could possibly act to produce these spatial structures. Our low-dimensional model gives a qualitative understanding of how generic physiological mechanisms can produce branching

  9. Analysis of spatial-temporal gene expression patterns reveals dynamics and regionalization in developing mouse brain

    PubMed Central

    Chou, Shen-Ju; Wang, Chindi; Sintupisut, Nardnisa; Niou, Zhen-Xian; Lin, Chih-Hsu; Li, Ker-Chau; Yeang, Chen-Hsiang

    2016-01-01

    Allen Brain Atlas (ABA) provides a valuable resource of spatial/temporal gene expressions in mammalian brains. Despite rich information extracted from this database, current analyses suffer from several limitations. First, most studies are either gene-centric or region-centric, thus are inadequate to capture the superposition of multiple spatial-temporal patterns. Second, standard tools of expression analysis such as matrix factorization can capture those patterns but do not explicitly incorporate spatial dependency. To overcome those limitations, we proposed a computational method to detect recurrent patterns in the spatial-temporal gene expression data of developing mouse brains. We demonstrated that regional distinction in brain development could be revealed by localized gene expression patterns. The patterns expressed in the forebrain, medullary and pontomedullary, and basal ganglia are enriched with genes involved in forebrain development, locomotory behavior, and dopamine metabolism respectively. In addition, the timing of global gene expression patterns reflects the general trends of molecular events in mouse brain development. Furthermore, we validated functional implications of the inferred patterns by showing genes sharing similar spatial-temporal expression patterns with Lhx2 exhibited differential expression in the embryonic forebrains of Lhx2 mutant mice. These analysis outcomes confirm the utility of recurrent expression patterns in studying brain development. PMID:26786896

  10. Development of the Next Generation Type Water Recovery System

    NASA Astrophysics Data System (ADS)

    Oguchi, Mitsuo; Tachihara, Satoru; Maeda, Yoshiaki; Ueoka, Terumi; Soejima, Fujito; Teranishi, Hiromitsu

    According to NASA, an astronaut living on the International Space Station (ISS) requires approximately 7 kg of water per day. This includes 2 kg of drinking water as well as sanitary fresh water for hand washing, gargling, etc. This water is carried to the space station from the earth, so when more people are staying on the space station, or staying for a longer period of time, the cost of transporting water increases. Accordingly, water is a valuable commodity, and restrictions are applied to such activities as brushing teeth, washing hair, and washing clothes. The life of an astronaut in space is not necessarily a healthy one. JAXA has experience in the research of water recovery systems. Today, utilizing knowledge learned through experiences living on the space station and space shuttles, and taking advantage of the development of new materials for device construction, it is possible to construct a new water recovery system. Therefore, JAXA and New Medican Tech Corporation (NMT) have created a system for collaborative development. Based on the technologies of both companies, we are proceeding to develop the next generation of water recovery devices in order to contribute to safe, comfortable, and healthy daily life for astronauts in space. The goal of this development is to achieve a water purification system based on reverse osmosis (RO) membranes that can perform the following functions. • Preprocessing that removes ammonia and breaks down organic matter contained in urine. • Post-processing that adds minerals and sterilizes the water. • Online TOC measurement for monitoring water quality. • Functions for measuring harmful substances. The RO membrane is an ultra-low-pressure type membrane with a 0.0001 micron (0.1 nanometer) pore size and an operating pressure of 0.4 to 0.6 MPa. During processing with the RO membrane, nearly all of the minerals contained in the cleaned water are removed, resulting in water that is near the quality of deionized water

  11. Development of pattern vision following early and extended blindness.

    PubMed

    Kalia, Amy; Lesmes, Luis Andres; Dorr, Michael; Gandhi, Tapan; Chatterjee, Garga; Ganesh, Suma; Bex, Peter J; Sinha, Pawan

    2014-02-01

    Visual plasticity peaks during early critical periods of normal visual development. Studies in animals and humans provide converging evidence that gains in visual function are minimal and deficits are most severe when visual deprivation persists beyond the critical period. Here we demonstrate visual development in a unique sample of patients who experienced extended early-onset blindness (beginning before 1 y of age and lasting 8-17 y) before removal of bilateral cataracts. These patients show surprising improvements in contrast sensitivity, an assay of basic spatial vision. We find that contrast sensitivity development is independent of the age of sight onset and that individual rates of improvement can exceed those exhibited by normally developing infants. These results reveal that the visual system can retain considerable plasticity, even after early blindness that extends beyond critical periods.

  12. Development of pattern vision following early and extended blindness

    PubMed Central

    Kalia, Amy; Lesmes, Luis Andres; Dorr, Michael; Gandhi, Tapan; Chatterjee, Garga; Ganesh, Suma; Bex, Peter J.; Sinha, Pawan

    2014-01-01

    Visual plasticity peaks during early critical periods of normal visual development. Studies in animals and humans provide converging evidence that gains in visual function are minimal and deficits are most severe when visual deprivation persists beyond the critical period. Here we demonstrate visual development in a unique sample of patients who experienced extended early-onset blindness (beginning before 1 y of age and lasting 8–17 y) before removal of bilateral cataracts. These patients show surprising improvements in contrast sensitivity, an assay of basic spatial vision. We find that contrast sensitivity development is independent of the age of sight onset and that individual rates of improvement can exceed those exhibited by normally developing infants. These results reveal that the visual system can retain considerable plasticity, even after early blindness that extends beyond critical periods. PMID:24449865

  13. Family patterns of development dyslexia, Part II: Behavioral phenotypes

    SciTech Connect

    Wolff, P.H.; Melngailis, I.; Bedrosian, M.

    1995-12-18

    The motor control of bimanual coordination and motor speech was compared between first degree relatives from families with at least 2 dyslexic family members, and families where probands were the only affected family members. Half of affected relatives had motor coordination deficits; and they came from families in which probands also showed impaired motor coordination. By contrast, affected relatives without motor deficits came from dyslexia families where probands did not have motor deficits. Motor coordination deficits were more common and more severe among affected offspring in families where both parents were affected than among affected offspring in families where only one parent was affected. However, motor coordination deficits were also more common and more severe in affected parents when both parents were affected than among affected parents in families where only one parent was affected. We conclude that impaired temporal resolution in motor action identifies a behavioral phenotype in some subtypes of developmental dyslexia. The observed pattern of transmission for motor deficits and reading impairment in about half of dyslexia families was most congruent with a genetic model of dyslexia in which 2 codominant major genes cosegregate in dyslexia pedigrees where the proband is also motorically impaired. 54 refs., 5 figs., 5 tabs.

  14. Not just black and white: pigment pattern development and evolution in vertebrates

    PubMed Central

    Mills, Margaret G.; Patterson, Larissa B.

    2009-01-01

    Animals display diverse colors and patterns that vary within and between species. Similar phenotypes appear in both closely related and widely divergent taxa. Pigment patterns thus provide an opportunity to explore how development is altered to produce differences in form and whether similar phenotypes share a common genetic basis. Understanding the development and evolution of pigment patterns requires knowledge of the cellular interactions and signaling pathways that produce those patterns. These complex traits provide unparalleled opportunities for integrating studies from ecology and behavior to molecular biology and biophysics. PMID:19073271

  15. Topologically Dissociable Patterns of Development of the Human Cerebral Cortex

    PubMed Central

    Vandekar, Simon N.; Shinohara, Russell T.; Raznahan, Armin; Roalf, David R.; Ross, Michelle; DeLeo, Nicholas; Ruparel, Kosha; Verma, Ragini; Wolf, Daniel H.; Gur, Ruben C.; Gur, Raquel E.

    2015-01-01

    Over 90 years ago, anatomists noted the cortex is thinner in sulci than gyri, suggesting that development may occur on a fine scale driven by local topology. However, studies of brain development in youth have focused on describing how cortical thickness varies over large-scale functional and anatomic regions. How the relationship between thickness and local sulcal topology arises in development is still not well understood. Here, we investigated the spatial relationships between cortical thickness, folding, and underlying white matter organization to elucidate the influence of local topology on human brain development. Our approach included using both T1-weighted imaging and diffusion tensor imaging (DTI) in a cross-sectional sample of 932 youths ages 8–21 studied as part of the Philadelphia Neurodevelopmental Cohort. Principal components analysis revealed separable development-related processes of regionally specific nonlinear cortical thickening (from ages 8–14) and widespread linear cortical thinning that have dissociable relationships with cortical topology. Whereas cortical thinning was most prominent in the depths of the sulci, early cortical thickening was present on the gyri. Furthermore, decline in mean diffusivity calculated from DTI in underlying white matter was correlated with cortical thinning, suggesting that cortical thinning is spatially associated with white matter development. Spatial permutation tests were used to assess the significance of these relationships. Together, these data demonstrate that cortical remodeling during youth occurs on a local topological scale and is associated with changes in white matter beneath the cortical surface. PMID:25589754

  16. Meteosat Third Generation (MTG) critical technology pre-development activities

    NASA Astrophysics Data System (ADS)

    Aminou, Donny M. A.; Bézy, Jean Loup; Meynart, Roland; Blythe, Paul; Kraft, S.; Zayer, I.; Linder, M.; Falkner, M.; Luhmann, H. J.

    2009-09-01

    ESA and EUMETSAT have initiated joint preparatory activities for the formulation and definition of the Meteosat Third Generation (MTG) geostationary system to ensure the future continuity, and enhancement, of the current Meteosat Second Generation (MSG) system. The MTG programmatics are being established to ensure a seamless transition between the conclusion of the successful MSG operational system and the start of the new MTG operational system, with particular emphasis on continuity of the imagery missions. The MTG phase A studies were successfully concluded in December 2008 an re-consolidation phase B1 activities continued from January to July 2009. They were devoted to the MTG concept definition and requirements consolidation for meeting the User needs in the field of Nowcasting and Very Short Term Weather Forecasting (NWC), Medium/Short Range global and regional Numerical Weather Prediction (NWP), Climate, Air Quality and Composition Monitoring. The following missions have been analysed, measurement techniques studied and preliminary concepts established: - High Resolution Fast Imagery Mission (improved successor to MSG SEVIRI HRV mission) - Full Disk High Spectral Resolution Imagery Mission (improved successor to SEVIRI) - Lightning Imagery Mission - IR Sounding Mission - UV-VIS-NIR Sounding Mission Both space segment architecture and preliminary satellite and instrument concepts were investigated in the course of these studies, and a dual satellite configuration established comprising the Imaging satellite (MTG-I) and the sounding satellite (MTG-S). The study covered all elements to a level of detail allowing to establish a technical baseline, conclude on the feasibility of the system requirements and undertake preliminary programmatic evaluation. Riders to the Phase A studies (Phase B1 work) have been placed to further consolidate the satellite and payload definition and development, prior to the release of the Invitation To Tender (ITT) for the full space

  17. Next generation sequencing for disorders of sex development.

    PubMed

    Tobias, Edward S; McElreavey, Ken

    2014-01-01

    Advances in sequencing technologies are having a major impact on our understanding of the genetic causes of many human congenital disorders. Next generation sequencing (NGS) approaches are particularly important for determining the inherited genetic changes leading to disorders of sex development (DSD). Knowledge of the genetic pathways involved in ovary or testis development is incomplete and, currently, a molecular diagnosis is made in a minority of DSD cases. Here, we review the different NGS strategies applied to the analysis of rare diseases and highlight the potential pitfalls and advantages that are associated with each approach. We also discuss the problems of variant calling as well as the challenges involved in the identification and interpretation of pathogenic mutations from NGS datasets. As clinics start to use NGS on a routine basis, a close collaboration between the molecular and clinical geneticists is essential. This is particularly relevant in the context of unsolicited genetic findings, where clear guidelines regarding counseling, truly informed consent and precise data interpretation will be invaluable.

  18. The development of 3rd generation IR detectors at AIM

    NASA Astrophysics Data System (ADS)

    Ziegler, J.; Eich, D.; Mahlein, M.; Schallenberg, T.; Scheibner, R.; Wendler, J.; Wenisch, J.; Wollrab, R.; Daumer, V.; Rehm, R.; Rutz, F.; Walther, M.

    2011-06-01

    3rd generation IR modules - dual-color (DC), dual-band (DB), and large format two-dimensional arrays - require sophisticated production technologies such as molecular beam epitaxy (MBE) as well as new array processing techniques, which can satisfy the rising demand for increasingly complex device structures and low cost detectors. AIM will extend its future portfolio by high performance devices which make use of these techniques. The DC MW / MW detectors are based on antimonide type-II superlattices (produced by MBE at Fraunhofer IAF, Freiburg) in the 384x288 format with a 40 μm pitch. For AIM, the technology of choice for MW / LW DB FPAs is MCT MBE on CdZnTe substrates, which has been developed in cooperation with IAF, Freiburg. 640x512, 20 μm pitch Focal Plane Arrays (FPAs) have been processed at AIM. The growth of MW MCT MBE layers on alternate substrates is challenging, but essential for competitive fabrication of large two-dimensional arrays such as megapixel (MW 1280x1024, 15 μm pitch) FPAs. This paper will present the development status and latest results of the above-mentioned 3rd Gen FPAs and Integrated Detector Cooler Assemblies (IDCAs).

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Use of adaptive network burst detection methods for multielectrode array data and the generation of artificial spike patterns for method evaluation

    NASA Astrophysics Data System (ADS)

    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 < 0.005). The improved method was also able to detect clustered, long-tailed and short-frequent NBs on real data. Significance. This work presents an objective method of assessing the applicability of NB detection methods for different neuronal activity patterns. Furthermore, it proposes an improved NB detection method that can

  1. Temporal patterns of tyrosine nitration in embryo heart development

    PubMed Central

    Viera, Liliana; Radmilovich, Milka; Vargas, Marcelo R.; Dennys, Cassandra N.; Wilson, Landon; Barnes, Stephen; Franco, Maria Clara; Beckman, Joseph S.; Estévez, Alvaro G.

    2012-01-01

    Tyrosine nitration is a biomarker for the production of peroxynitrite and other reactive nitrogen species. Nitrotyrosine immunoreactivity is present in many pathological conditions including several cardiac diseases. Because the events observed during heart failure may recapitulate some aspects of development, we tested whether nitrotyrosine is present during normal development of the rat embryo heart and its potential relationship in cardiac remodeling through apoptosis. Nitric oxide (NO) production is highly dynamic during development, but whether peroxynitrite and nitrotyrosine are formed during normal embryonic development has received little attention. Rat embryo hearts exhibited strong nitrotyrosine immunoreactivity in endocardial and myocardial cells of the atria and ventricles from E12 to E18. After E18, nitrotyrosine staining faded and disappeared entirely by birth. Tyrosine nitration in the myocardial tissue coincided with elevated protein expression of nitric oxide synthases (eNOS and iNOS). The immunoreactivity for these NOS isoforms remained elevated even after nitrotyrosine had disappeared. Tyrosine nitration did not correlate with cell death or proliferation of cardiac cells. Analysis of tryptic peptides by MALDI-TOF shows that nitration occurs in actin, myosin, and the mitochondrial ATP synthase alpha chain. These results suggest that reactive nitrogen species are not restricted to pathological conditions but may play a role during normal embryonic development. PMID:23195686

  2. 5-HT receptors involved in initiation or modulation of motor patterns: opportunities for drug development.

    PubMed

    Wallis, D I

    1994-08-01

    A clearer understanding of the role of descending systems in motor control can be achieved by using in vitro preparations of mammalian spinal cord that display patterned motor output, together with the use of selective pharmacological agents. It has been suggested that 5-HT is involved in either the initiation or the modulation of certain motor behaviours, and that it acts to enhance or regulate the motor pattern. Most attention has been paid to the locomotor rhythms underlying walking or swimming, and in respiratory pattern generation. In this article, David Wallis discusses the involvement of 5-HT1 and 5-HT2 receptors in these processes and the possible therapeutic relevance.

  3. Segregating neural and mechanosensory fates in the developing ear: patterning, signaling, and transcriptional control.

    PubMed

    Raft, Steven; Groves, Andrew K

    2015-01-01

    The vertebrate inner ear is composed of multiple sensory receptor epithelia, each of which is specialized for detection of sound, gravity, or angular acceleration. Each receptor epithelium contains mechanosensitive hair cells, which are connected to the brainstem by bipolar sensory neurons. Hair cells and their associated neurons are derived from the embryonic rudiment of the inner ear epithelium, but the precise spatial and temporal patterns of their generation, as well as the signals that coordinate these events, have only recently begun to be understood. Gene expression, lineage tracing, and mutant analyses suggest that both neurons and hair cells are generated from a common domain of neural and sensory competence in the embryonic inner ear rudiment. Members of the Shh, Wnt, and FGF families, together with retinoic acid signals, regulate transcription factor genes within the inner ear rudiment to establish the axial identity of the ear and regionalize neurogenic activity. Close-range signaling, such as that of the Notch pathway, specifies the fate of sensory regions and individual cell types. We also describe positive and negative interactions between basic helix-loop-helix and SoxB family transcription factors that specify either neuronal or sensory fates in a context-dependent manner. Finally, we review recent work on inner ear development in zebrafish, which demonstrates that the relative timing of neurogenesis and sensory epithelial formation is not phylogenetically constrained.

  4. Spike Pattern Structure Influences Synaptic Efficacy Variability under STDP and Synaptic Homeostasis. I: Spike Generating Models on Converging Motifs

    PubMed Central

    Bi, Zedong; Zhou, Changsong

    2016-01-01

    In neural systems, synaptic plasticity is usually driven by spike trains. Due to the inherent noises of neurons and synapses as well as the randomness of connection details, spike trains typically exhibit variability such as spatial randomness and temporal stochasticity, resulting in variability of synaptic changes under plasticity, which we call efficacy variability. How the variability of spike trains influences the efficacy variability of synapses remains unclear. In this paper, we try to understand this influence under pair-wise additive spike-timing dependent plasticity (STDP) when the mean strength of plastic synapses into a neuron is bounded (synaptic homeostasis). Specifically, we systematically study, analytically and numerically, how four aspects of statistical features, i.e., synchronous firing, burstiness/regularity, heterogeneity of rates and heterogeneity of cross-correlations, as well as their interactions influence the efficacy variability in converging motifs (simple networks in which one neuron receives from many other neurons). Neurons (including the post-synaptic neuron) in a converging motif generate spikes according to statistical models with tunable parameters. In this way, we can explicitly control the statistics of the spike patterns, and investigate their influence onto the efficacy variability, without worrying about the feedback from synaptic changes onto the dynamics of the post-synaptic neuron. We separate efficacy variability into two parts: the drift part (DriftV) induced by the heterogeneity of change rates of different synapses, and the diffusion part (DiffV) induced by weight diffusion caused by stochasticity of spike trains. Our main findings are: (1) synchronous firing and burstiness tend to increase DiffV, (2) heterogeneity of rates induces DriftV when potentiation and depression in STDP are not balanced, and (3) heterogeneity of cross-correlations induces DriftV together with heterogeneity of rates. We anticipate our work

  5. IEC International Standards Under Development For Radiation-Generating Devices

    SciTech Connect

    Voytchev, M; Radev, R; Chiaro, P; Thomson, I; Dray, C; Li, J

    2007-12-06

    The International Electrotechnical Commission (IEC) is the leading and oldest global organization with over 100 years history of developing and publishing international standards for all electrical, electronic and related technologies, including radiation detection instrumentation. Subcommittee 45B 'Radiation Protection Instrumentation' of the IEC has recently started the development of two standards on radiation-generating devices. IEC 62463 'Radiation protection instrumentation--X-ray Systems for the Screening of Persons for Security and the Carrying of Illicit Items' is applicable to X-ray systems designed for screening people to detect if they are carrying objects such as weapons, explosives, chemical and biological agents and other concealed items that could be used for criminal purposes, e.g. terrorist use, drug smuggling, etc. IEC 62523 'Radiation protection instrumentation--Cargo/Vehicle radiographic inspection systems' applies to cargo/vehicle imaging inspection systems using accelerator produced X-ray or gamma radiation to obtain images of the screened objects (e.g. cargo containers, transport and passenger vehicles and railroad cars). The objective of both standards is to specify standard requirements and general characteristics and test procedures, as well as, radiation, electrical, environmental, mechanical, and safety requirements and to provide examples of acceptable methods to test these requirements. In particular the standards address the design requirements as they relate to the radiation protection of the people being screened, people who are in the vicinity of the equipment and the operators. The standard IEC 62463 does not deal with the performance requirements for the quality of the object detection. Compliance with the standards requirements will provide the manufacturers with internationally acceptable specifications and the device users with assurance of the rigorous quality and accuracy of the measurements in relation to the radiological

  6. Developments of next generation of seafloor observatories in MARsite project

    NASA Astrophysics Data System (ADS)

    Italiano, Francesco; Favali, Paolo; Zaffuto, Alfonso; Zora, Marco; D'Anca, Fabio

    2015-04-01

    The development of new generation of autonomous sea-floor observatories is among the aims of the EC supersite project MARsite (MARMARA Supersite; FP7 EC-funded project, grant n° 308417). An approach based on multiparameter seafloor observatories is considered of basic importance to better understand the role of the fluids in an active tectonic system and their behaviour during the development of the seismogenesis. To continuously collect geochemical and geophysical data from the immediate vicinity of the submerged North Anatolian Fault Zone (NAFZ) is one of the possibilities to contribute to the seismic hazard minimization of the Marmara area. The planning of next generation of seafloor observatories for geo-hazard monitoring is a task in one of the MARsite Work Packages (WP8). The activity is carried out combining together either the experience got after years of investigating fluids and their interactions with the seafloor and tectonic structures and the long-term experience on the development and management of permanent seafloor observatories in the main frame of the EMSO (European Multidisciplinary Seafloor and water-column Observatory, www.emso-eu.org) Research Infrastructure. The new generation of seafloor observatories have to support the observation of both slow and quick variations, thus allow collecting low and high-frequency signals besides the storage of long-term dataset and/or enable the near-real-time mode data transmission. Improvements of some the seafloor equipments have been done so far within MARsite project in terms of the amount of contemporary active instruments, their interlink with "smart sensor" capacities (threshold detection, triggering), quality of the collected data and power consumption reduction. In order to power the multiparameter sensors the digitizer and the microprocessor, an electronic board named PMS (Power Management System) with multi-master, multi-slave, single-ended, serial bus Inter-Integrated Circuit (I²C) interface

  7. Speech Development Patterns and Phonological Awareness in Preschool Children

    ERIC Educational Resources Information Center

    Mann, Virginia A.; Foy, Judith G.

    2007-01-01

    To examine the association between speech production and early literacy skills, this study of 102 preschool children looked at phonological awareness in relation to whether children were delayed, typical, or advanced in their articulation of consonants. Using a developmental typology inspired by some of the literature on speech development (Kahn…

  8. Development of Prosodic Patterns in Mandarin-Learning Infants

    ERIC Educational Resources Information Center

    Chen, Li-Mei; Kent, Raymond D.

    2009-01-01

    Early prosodic development (f[subscript 0] variation) was systematically measured in Mandarin-learning infants at the transition from babbling to producing first words. Spontaneous vocalizations of twenty-four infants aged 0;7 to 1;6 were recorded in 45-minute sessions. The speech production of twenty-four caregivers was also audio-recorded during…

  9. The 2nd Generation Real Time Mission Monitor (RTMM) Development

    NASA Astrophysics Data System (ADS)

    Blakeslee, R. J.; Goodman, M.; Hardin, D. M.; Hall, J.; Yubin He, M.; Regner, K.; Conover, H.; Smith, T.; Meyer, P.; Lu, J.; Garrett, M.

    2009-12-01

    The NASA Real Time Mission Monitor (RTMM) is a visualization and information system that fuses multiple Earth science data sources, to enable real time decision-making for airborne and ground validation experiments. Developed at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center, RTMM is a situational awareness, decision-support system that integrates satellite imagery and orbit data, radar and other surface observations (e.g., lightning location network data), airborne navigation and instrument data sets, model output parameters, and other applicable Earth science data sets. The integration and delivery of this information is made possible using data acquisition systems, network communication links, network server resources, and visualizations through the Google Earth virtual globe application. In order to improve the usefulness and efficiency of the RTMM system, capabilities are being developed to allow the end-user to easily configure RTMM applications based on their mission-specific requirements and objectives. This second generation RTMM is being redesigned to take advantage of the Google plug-in capabilities to run multiple applications in a web browser rather than the original single application Google Earth approach. Currently RTMM employs a limited Service Oriented Architecture approach to enable discovery of mission specific resources. We are expanding the RTMM architecture such that it will more effectively utilize the Open Geospatial Consortium Sensor Web Enablement services and other new technology software tools and components. These modifications and extensions will result in a robust, versatile RTMM system that will greatly increase flexibility of the user to choose which science data sets and support applications to view and/or use. The improvements brought about by RTMM 2nd generation system will provide mission planners and airborne scientists with enhanced decision-making tools and capabilities to more

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

    PubMed

    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.

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

    SciTech Connect

    Delgado Otoniel, Buenrostro

    2008-07-01

    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 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.

  12. Optical generation of a circular harmonic filter for rotation and translation invariant optical pattern recognition

    NASA Technical Reports Server (NTRS)

    Cheng, Yeou-Yen

    1987-01-01

    A new method to generate a circular harmonic filter with both rotation and translation invariance is described, which is based on a phase-shifted double-exposure (PSDE) technique. An expression for the peak correlation intensity at the origin for the correlation plane as a function of target orientation for the PSDE filter is derived. Experimental results confirming the theoretical predictions are provided.

  13. Next Generation Nuclear Plant Materials Research and Development Program Plan

    SciTech Connect

    G.O. Hayner; R.L. Bratton; R.N. Wright

    2005-09-01

    The U.S Department of Energy (DOE) has selected the Very High Temperature Reactor (VHTR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production without greenhouse gas emissions. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed, thermal neutron spectrum reactor that will produce electricity and hydrogen in a state-of-the-art thermodynamically efficient manner. The NGNP will use very high burn-up, low-enriched uranium, TRISO-coated fuel and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Project is envisioned to demonstrate the following: (1) A full-scale prototype VHTR by about 2021; (2) High-temperature Brayton Cycle electric power production at full scale with a focus on economic performance; (3) Nuclear-assisted production of hydrogen (with about 10% of the heat) with a focus on economic performance; and (4) By test, the exceptional safety capabilities of the advanced gas-cooled reactors. Further, the NGNP program will: (1) Obtain a Nuclear Regulatory Commission (NRC) License to construct and operate the NGNP, this process will provide a basis for future performance based, risk-informed licensing; and (2) Support the development, testing, and prototyping of hydrogen infrastructures. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. The NGNP Materials R&D Program includes the following elements: (1) Developing a specific approach, program plan and other project management tools for

  14. Podoplanin and CLEC-2 drive cerebrovascular patterning and integrity during development

    PubMed Central

    Lowe, Kate L.; Finney, Brenda A.; Deppermann, Carsten; Hägerling, René; Gazit, Salomé L.; Frampton, Jon; Buckley, Christopher; Camerer, Eric; Nieswandt, Bernhard; Kiefer, Friedemann

    2015-01-01

    Mice with a constitutive or platelet-specific deletion of the C-type-lectin-like receptor (CLEC-2) exhibit hemorrhaging in the brain at mid-gestation. We sought to investigate the basis of this defect, hypothesizing that it is mediated by the loss of CLEC-2 activation by its endogenous ligand, podoplanin, which is expressed on the developing neural tube. To induce deletion of podoplanin at the 2-cell stage, we generated a podoplaninfl/fl mouse crossed to a PGK-Cre mouse. Using 3-dimensional light-sheet microscopy, we observed cerebral vessels were tortuous and aberrantly patterned at embryonic (E) day 10.5 in podoplanin- and CLEC-2-deficient mice, preceding the formation of large hemorrhages throughout the fore-, mid-, and hindbrain by E11.5. Immunofluorescence and electron microscopy revealed defective pericyte recruitment and misconnections between the endothelium of developing blood vessels and surrounding pericytes and neuro-epithelial cells. Nestin-Cre-driven deletion of podoplanin on neural progenitors also caused widespread cerebral hemorrhaging. Hemorrhaging was also seen in the ventricles of embryos deficient in the platelet integrin subunit glycoprotein IIb or in embryos in which platelet α-granule and dense granule secretion is abolished. We propose a novel role for podoplanin on the neuro-epithelium, which interacts with CLEC-2 on platelets, mediating platelet adhesion, aggregation, and secretion to guide the maturation and integrity of the developing vasculature and prevent hemorrhage. PMID:25908104

  15. Proposal for the development of 3D Vertically Integrated Pattern Recognition Associative Memory (VIPRAM)

    SciTech Connect

    Deptuch, Gregory; Hoff, Jim; Kwan, Simon; Lipton, Ron; Liu, Ted; Ramberg, Erik; Todri, Aida; Yarema, Ray; Demarteua, Marcel,; Drake, Gary; Weerts, Harry; /Argonne /Chicago U. /Padua U. /INFN, Padua

    2010-10-01

    Future particle physics experiments looking for rare processes will have no choice but to address the demanding challenges of fast pattern recognition in triggering as detector hit density becomes significantly higher due to the high luminosity required to produce the rare process. The authors propose to develop a 3D Vertically Integrated Pattern Recognition Associative Memory (VIPRAM) chip for HEP applications, to advance the state-of-the-art for pattern recognition and track reconstruction for fast triggering.

  16. Development of microsatellite markers for Sargentodoxa cuneata (Lardizabalaceae) using next-generation sequencing technology1

    PubMed Central

    Sun, Zhi-Xia; Ye, Lin-Jiang; Zhang, Fei; Hu, Wan; Fan, Deng-Mei; Zhang, Zhi-Yong

    2016-01-01

    Premise of the study: Microsatellite loci were developed for a woody deciduous liana, Sargentodoxa cuneata (Lardizabalaceae), to help infer the evolutionary histories of ancient monotypic genera in subtropical China. Methods and Results: Using next-generation sequencing (Illumina MiSeq) technology, 21 polymorphic primer sets were identified in three wild populations. The number of alleles per locus ranged from one to seven. The expected and observed heterozygosities varied from 0 to 0.788 and 0 to 0.917, respectively. Transferability analyses were performed in Stauntonia chinensis, Akebia trifoliata, and A. quinata. Eighteen (85.7%), 18 (85.7%), and 17 (81.0%) markers were successfully amplified, respectively. Conclusions: The newly developed markers will facilitate further studies on genetic diversity and phylogeographic patterns throughout the distributional range of S. cuneata. This set of microsatellite primers represents the second report on molecular markers in Lardizabalaceae. PMID:27213128

  17. Development of Decision Model for Selection of Appropriate Power Generation System Using Distance Based Approach Method

    NASA Astrophysics Data System (ADS)

    Widiyanto, Anugerah; Kato, Seizo; Maruyama, Naoki

    For solving decision problems in electric generation planning, a matrix operation based deterministic quantitative model called the Distance Based Approach (DBA) has been proposed for comparing the technical-economical and environmental features of various electric power plants. The customized computer code is developed to evaluate the overall function of alternative energy systems from the performance pattern corresponding to the selected energy attributes. For the purpose of exploring the applicability and the effectiveness of the proposed model, the model is applied to decision problems concerning the selection of energy sources for power generation in Japan. The set of nine energy alternatives includes conventional and new energy technologies of oil fired-, natural gas fired-, coal fired-, nuclear power, hydropower, geothermal, solar photovoltaic, wind power and solar thermal plants. Also, a set of criteria for optimized selection includes five areas of concern; energy economy, energy security, environmental protection, socio-economic development and technological aspects for electric power generation. The result will be a ranking of alternative sources of energy based on the Euclidean composite distance of each alternative to the designated optimal source of energy.

  18. Spatiotemporal patterns of Musashi1 expression during inner ear development.

    PubMed

    Sakaguchi, Hirofumi; Yaoi, Takeshi; Suzuki, Toshihiro; Okano, Hideyuki; Hisa, Yasuo; Fushiki, Shinji

    2004-04-29

    Musashi1 (Msi 1) is an RNA binding protein associated with asymmetric cell divisions in neural progenitor cells. To investigate the involvement of Msi1 in the inner ear development, we studied the expression of Msi1 in mouse inner ears with RT-PCR and immunohistochemistry. Immunohistochemistry revealed that Msi1 was expressed in all otocyst cells at embryonic day (E) 10 and 12. Msi1 immunoreactivity became lost in hair cells after E14 in vestibule and after E16 in cochlea, whereas it persisted in supporting cells until adulthood. The subcellular localization of Msi1 changed from "cytoplasmic predominance" to "nuclear predominance" during the first 2 weeks after birth. The present data suggested that Msi may play a role in inner ear development. PMID:15076722

  19. Two-dimensional stick slip on a soft elastic polymer: pattern generation using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Watson, J. A.; Brown, C. L.; Myhra, S.; Watson, G. S.

    2006-05-01

    It has been demonstrated that it is possible to create laterally differentiated frictional patterning and three-dimensional structures using an atomic force microscope (AFM) probe on the surface of a soft elastic polymer, poly(dimethylsiloxane) (PDMS). The resulting effect of contact mode imaging at low loading forces (<100 nN), observed in the lateral force mode, revealed a homogeneous pattern on the PDMS surface exhibiting higher friction. With higher loading forces ({\\gg }100 nN) the effect is non-uniform, resulting in structures with depths on the nanometre scale. The topographic and frictional data revealed stick-slip responses in both the fast (orthogonal to the long axis of the lever) and slow (parallel to the long axis of the lever) directions of probe travel from scanning in a raster pattern. The stick-slip events are manifested in the form of a series of shallow channels spaced evenly apart on the polymer surface. Detailed friction loop analysis acquired during the manipulation process showed that the lateral force changed according to the strength of trapping of the tip with the polymer surface exhibiting significant in-plane deformation due to lateral forces being imposed. An incremental increase in the initial loading force resulted in an increase in in-plane displacement and a greater spacing between the stick lines/channels in the slow-scan direction. A decrease in channel length in the fast-scan direction is also observed as a result of an increase in static friction with normal force, resulting in greater surface deformation and shorter track length for sliding friction.

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

    PubMed Central

    Johnson, Gregory R.; Li, Jieyue; Shariff, Aabid; Rohde, Gustavo K.; Murphy, Robert F.

    2015-01-01

    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. PMID:26624011

  1. First-generation black-hole-forming supernovae and the metal abundance pattern of a very iron-poor star.

    PubMed

    Umeda, Hideyuki; Nomoto, Ken'ichi

    2003-04-24

    It has been proposed theoretically that the first generation of stars in the Universe (population III) would be as massive as 100 solar masses (100 M(O)), because of inefficient cooling of the precursor gas clouds. Recently, the most iron-deficient (but still carbon-rich) low-mass star--HE0107-5240--was discovered. If this is a population III star that gained its metals (elements heavier than helium) after its formation, it would challenge the theoretical picture of the formation of the first stars. Here we report that the patterns of elemental abundance in HE0107-5240 (and other extremely metal-poor stars) are in good accord with the nucleosynthesis that occurs in stars with masses of 20-130 M(O) when they become supernovae if, during the explosions, the ejecta undergo substantial mixing and fallback to form massive black holes. Such supernovae have been observed. The abundance patterns are not, however, consistent with enrichment by supernovae from stars in the range 130-300 M(O). We accordingly infer that the first-generation supernovae came mostly from explosions of approximately 20-130 M(O) stars; some of these produced iron-poor but carbon- and oxygen-rich ejecta. Low-mass second-generation stars, like HE0107-5240, could form because the carbon and oxygen provided pathways for the gas to cool.

  2. Next Generation Nuclear Plant Research and Development Program Plan

    SciTech Connect

    2005-01-01

    The U.S Department of Energy (DOE) is conducting research and development (R&D) on the Very High Temperature Reactor (VHTR) design concept for the Next Generation Nuclear Plant (NGNP) Project. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner. The NGNP reactor core could be either a prismatic graphite block type core or a pebble bed core. Use of a liquid salt coolant is also being evaluated. The NGNP will use very high-burnup, low-enriched uranium, TRISO-coated fuel, and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The objectives of the NGNP Project are to: (1) Demonstrate a full-scale prototype VHTR that is commercially licensed by the U.S. Nuclear Regulatory Commission (2) Demonstrate safe and economical nuclear-assisted production of hydrogen and electricity. The DOE laboratories, led by the INL, will perform R&D that will be critical to the success of the NGNP, primarily in the areas of: (1) High temperature gas reactor fuels behavior; (2) High temperature materials qualification; (3) Design methods development and validation; (4) Hydrogen production technologies; and (5) Energy conversion. The current R&D work is addressing fundamental issues that are relevant to a variety of possible NGNP designs. This document describes the NGNP R&D planned and currently underway in the first three topic areas listed above. The NGNP Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is presented in Section 2, the NGNP Materials R&D Program Plan is presented in Section 3, and the NGNP Design Methods Development and Validation R&D Program is presented

  3. Next Generation Nuclear Plant Research and Development Program Plan

    SciTech Connect

    P. E. MacDonald

    2005-01-01

    The U.S Department of Energy (DOE) is conducting research and development (R&D) on the Very High Temperature Reactor (VHTR) design concept for the Next Generation Nuclear Plant (NGNP) Project. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner. The NGNP reactor core could be either a prismatic graphite block type core or a pebble bed core. Use of a liquid salt coolant is also being evaluated. The NGNP will use very high-burnup, low-enriched uranium, TRISO-coated fuel, and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The objectives of the NGNP Project are to: Demonstrate a full-scale prototype VHTR that is commercially licensed by the U.S. Nuclear Regulatory Commission Demonstrate safe and economical nuclearassisted production of hydrogen and electricity. The DOE laboratories, led by the INL, will perform R&D that will be critical to the success of the NGNP, primarily in the areas of: High temperature gas reactor fuels behavior High temperature materials qualification Design methods development and validation Hydrogen production technologies Energy conversion. The current R&D work is addressing fundamental issues that are relevant to a variety of possible NGNP designs. This document describes the NGNP R&D planned and currently underway in the first three topic areas listed above. The NGNP Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is presented in Section 2, the NGNP Materials R&D Program Plan is presented in Section 3, and the NGNP Design Methods Development and Validation R&D Program is presented in Section 4. The DOE-funded hydrogen

  4. Development and validation of a new bitumen fume generation system which generates polycyclic aromatic hydrocarbon concentrations proportional to fume concentrations.

    PubMed

    Binet, S; Bonnet, P; Brandt, H; Castegnaro, M; Delsaut, P; Fabries, J F; Huynh, C K; Lafontaine, M; Morel, G; Nunge, H; Rihn, B; Vu Duc, T; Wrobel, R

    2002-10-01

    Bitumen fumes emitted during road paving and roofing contain polycyclic aromatic compounds (PACs) of potential health concern. Little information is available for an experimental device devoted to inhalation experiments with animals exposed to bitumen fumes, and in all studies the systems were never validated for a range of fume concentrations, which prohibited their use for toxicological concentration-effect studies. Therefore, the purpose of this study was to validate a new experimental device able to generate bitumen fumes at different total particulate matter (TPM) concentrations with a linear correlation between TPM and the concentrations of different PACs, thus allowing toxicological dose-response studies with fumes representative of those in the field. Atmosphere samples collected from an animal exposure chamber allowed the determination of TPM, toluene soluble matter, polycyclic aromatic hydrocarbons (PAHs) and semi-volatiles. The particulate size distributions were determined in order to assess the deposition pattern in the respiratory tract. The temperature of 170 degrees C was chosen by analogy with the upper range of the temperature used during paving operations. The temperature of the air passing over the fume emission area was regulated to 20 degrees C and stirring of the heated bitumen was restricted to 90 r.p.m. The data show that the objective of developing a static fume generation system that reproducibly produces fumes in the inhalation chamber for specified target concentrations (TPM) were successful. The within-day variation coefficients for TPM were between 2.5 and 6.1%. The day-to-day variations for TPM concentration were between 4.1 and 5.8%. The concentrations of the 4-5 ring PAHs and the polycyclic aromatic sulphur heterocycles were proportional to the TPM concentration. The 2 and 3 ring PAH concentrations showed a deviation from proportionality with the TPM, probably due to their re-evaporation during sampling. The mass median aerodynamic

  5. Development of Electricity Generation from Renewable Energy Sources in Turkey

    NASA Astrophysics Data System (ADS)

    Kentel, E.

    2011-12-01

    Electricity is mainly produced from coal, natural gas and hydropower in Turkey. However, almost all the natural gas and high quality coal are imported. Thus, increasing the shares of both hydro and other renewables in energy supply is necessary to decrease dependency of the country on foreign sources. In 2008, the total installed capacity of Turkey was around 42000 MW and 66 % of this was from thermal sources. The remaining 33 % was from hydro, which leaves only one percent for the other renewable energy sources. The share of renewable energy in the energy budget of Turkey has increased in the last two decades; however, in 2008, only 17 % of the total electricity generation was realized from renewable sources most of which was hydro. According to State Hydraulic Works (SHW) which is the primary executive state agency responsible for the planning, operating and managing of Turkey's water resources, Turkey utilizes only around 35% of its economically viable hydro potential. The current situation clearly demonstrates the need for increasing the share of renewables in the energy budget. New laws, such as the Electricity Market Law, have been enacted and the following items were identified by the Ministry of Energy and Natural Resources of Turkey among primary energy policies and priorities: (i) decreasing dependency on foreign resources by prioritizing utilization of natural resources, (ii) increasing the share of renewable energy resources in the energy budget of Turkey; (iii) minimization of adverse environmental impacts of production and utilization of natural resources. The government's energy policy increased investments in renewable energy resources; however lack of a needed legal framework brought various environmental and social problems with this fast development. The development of the share of renewable resources in the energy budget, current government policy, and environmental concerns related with renewables, and ideas to improve the overall benefits of

  6. Understanding Generational Diversity: Strategic Human Resource Management and Development across the Generational "Divide"

    ERIC Educational Resources Information Center

    Amayah, Angela Titi; Gedro, Julie

    2014-01-01

    There are more generations in today's workforce than ever before, which has the possibility to create challenges for Human Resource professionals. The purpose of this article is to interrogate existing stereotypes and generalities about the characteristics of different generations with respect to the workplace, and to offer suggestions for…

  7. Sowing Seeds for Future Generations: Development of Generative Concern and Its Relation to Environmental Narrative Identity

    ERIC Educational Resources Information Center

    Jia, Fanli; Soucie, Kendall; Alisat, Susan; Pratt, Michael

    2016-01-01

    In this longitudinal study, we examined the relationship between the trajectory of generative concern measured at ages 23, 26 and 32 and environmental narrative identity at age 32. Canadian participants completed a questionnaire on generative concern at ages 23, 26 and 32 and were then interviewed about their personal experiences with the…

  8. Patterns of miRNA expression in Arctic charr development.

    PubMed

    Kapralova, Kalina H; Franzdóttir, Sigrídur Rut; Jónsson, Hákon; Snorrason, Sigurður S; Jónsson, Zophonías O

    2014-01-01

    Micro-RNAs (miRNAs) are now recognized as a major class of developmental regulators. Sequences of many miRNAs are highly conserved, yet they often exhibit temporal and spatial heterogeneity in expression among species and have been proposed as an important reservoir for adaptive evolution and divergence. With this in mind we studied miRNA expression during embryonic development of offspring from two contrasting morphs of the highly polymorphic salmonid Arctic charr (Salvelinus alpinus), a small benthic morph from Lake Thingvallavatn (SB) and an aquaculture stock (AC). These morphs differ extensively in morphology and adult body size. We established offspring groups of the two morphs and sampled at several time points during development. Four time points (3 embryonic and one just before first feeding) were selected for high-throughput small-RNA sequencing. We identified a total of 326 conserved and 427 novel miRNA candidates in Arctic charr, of which 51 conserved and 6 novel miRNA candidates were differentially expressed among developmental stages. Furthermore, 53 known and 19 novel miRNAs showed significantly different levels of expression in the two contrasting morphs. Hierarchical clustering of the 53 conserved miRNAs revealed that the expression differences are confined to the embryonic stages, where miRNAs such as sal-miR-130, 30, 451, 133, 26 and 199a were highly expressed in AC, whereas sal-miR-146, 183, 206 and 196a were highly expressed in SB embryos. The majority of these miRNAs have previously been found to be involved in key developmental processes in other species such as development of brain and sensory epithelia, skeletogenesis and myogenesis. Four of the novel miRNA candidates were only detected in either AC or SB. miRNA candidates identified in this study will be combined with available mRNA expression data to identify potential targets and involvement in developmental regulation. PMID:25170615

  9. Patterns of MiRNA Expression in Arctic Charr Development

    PubMed Central

    Kapralova, Kalina H.; Franzdóttir, Sigrídur Rut; Jónsson, Hákon; Snorrason, Sigurður S.; Jónsson, Zophonías O.

    2014-01-01

    Micro-RNAs (miRNAs) are now recognized as a major class of developmental regulators. Sequences of many miRNAs are highly conserved, yet they often exhibit temporal and spatial heterogeneity in expression among species and have been proposed as an important reservoir for adaptive evolution and divergence. With this in mind we studied miRNA expression during embryonic development of offspring from two contrasting morphs of the highly polymorphic salmonid Arctic charr (Salvelinus alpinus), a small benthic morph from Lake Thingvallavatn (SB) and an aquaculture stock (AC). These morphs differ extensively in morphology and adult body size. We established offspring groups of the two morphs and sampled at several time points during development. Four time points (3 embryonic and one just before first feeding) were selected for high-throughput small-RNA sequencing. We identified a total of 326 conserved and 427 novel miRNA candidates in Arctic charr, of which 51 conserved and 6 novel miRNA candidates were differentially expressed among developmental stages. Furthermore, 53 known and 19 novel miRNAs showed significantly different levels of expression in the two contrasting morphs. Hierarchical clustering of the 53 conserved miRNAs revealed that the expression differences are confined to the embryonic stages, where miRNAs such as sal-miR-130, 30, 451, 133, 26 and 199a were highly expressed in AC, whereas sal-miR-146, 183, 206 and 196a were highly expressed in SB embryos. The majority of these miRNAs have previously been found to be involved in key developmental processes in other species such as development of brain and sensory epithelia, skeletogenesis and myogenesis. Four of the novel miRNA candidates were only detected in either AC or SB. miRNA candidates identified in this study will be combined with available mRNA expression data to identify potential targets and involvement in developmental regulation. PMID:25170615

  10. The generation of biomolecular patterns in highly porous collagen-GAG scaffolds using direct photolithography.

    PubMed

    Martin, Teresa A; Caliari, Steven R; Williford, Paul D; Harley, Brendan A; Bailey, Ryan C

    2011-06-01

    The extracellular matrix (ECM) is a complex organization of structural proteins found within tissues and organs. Heterogeneous tissues with spatially and temporally modulated properties play an important role in organism physiology. Here we present a benzophenone (BP) based direct, photolithographic approach to spatially pattern solution phase biomolecules within collagen-GAG (CG) scaffolds and demonstrate creation of a wide range of patterns composed of multiple biomolecular species in a manner independent from scaffold fabrication steps. We demonstrate the ability to immobilize biomolecules at surface densities of up to 1000 ligands per square micron on the scaffold strut surface and to depths limited by the penetration depth of the excitation source into the scaffold structure. Importantly, while BP photopatterning does further crosslink the CG scaffold, evidenced by increased mechanical properties and collagen crystallinity, it does not affect scaffold microstructural or compositional properties or negatively influence cell adhesion, viability, or proliferation. We show that covalently photoimmobilized fibronectin within a CG scaffold significantly increases the speed of MC3T3-E1 cell attachment relative to the bare CG scaffold or non-specifically adsorbed fibronectin, suggesting that this approach can be used to improve scaffold bioactivity. Our findings, on the whole, establish the use of direct, BP photolithography as a methodology for covalently incorporating activity-improving biochemical cues within 3D collagen biomaterial scaffolds with spatial control over biomolecular deposition.

  11. Ecological coherence of diversity patterns derived from classical fingerprinting and Next Generation Sequencing techniques.

    PubMed

    Gobet, Angélique; Boetius, Antje; Ramette, Alban

    2014-09-01

    Changes in richness and bacterial community structure obtained via 454 Massively Parallel Tag Sequencing (MPTS) and Automated Ribosomal Intergenic Analysis (ARISA) were systematically compared to determine whether and how the ecological knowledge obtained from both molecular techniques could be combined. We evaluated community changes over time and depth in marine coastal sands at different levels of taxonomic resolutions, sequence corrections and sequence abundances. Although richness over depth layers or sampling dates greatly varied [∼ 30% and 70-80% new operational taxonomic units (OTU) between two samples with ARISA and MPTS respectively], overall patterns of community variations were similar with both approaches. Alpha-diversity estimated by ARISA-derived OTU was most similar to that obtained from MPTS-derived OTU defined at the order level. Similar patterns of OTU replacement were also found with MPTS at the family level and with 20-25% rare types removed. Using ARISA or MPTS datasets with lower resolution, such as those containing only resident OTU, yielded a similar set of significant contextual variables explaining bacterial community changes. Hence, ARISA as a rapid and low-cost fingerprinting technique represents a valid starting point for more in-depth exploration of community composition when complemented by the detailed taxonomic description offered by MPTS.

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

    PubMed

    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.

  13. Pattern and manipulation of follicular development in Bos indicus cattle.

    PubMed

    Bó, G A; Baruselli, P S; Martínez, M F

    2003-10-15

    Bos indicus cattle are widespread in tropical regions due to their adaptation to these environments. Although data on reproductive performance have indicated both inferior and superior results for B. indicus cattle, there is little doubt that B. indicus cattle are superior than Bos taurus cattle when they are both kept in tropical or subtropical environments, where stressors like hot temperatures, humidity, ectoparasites and low quality forages are greater. Reproductive endocrinology and oestrus behaviour of the B. indicus cattle have been studied for over 30 years; however, the application of technologies such as real time ultrasonography and Heat-Watch systems has expanded our knowledge on the ovarian follicular-wave dynamics during the oestrous cycle and the time of ovulation. Ovarian follicular dynamics in B. indicus cattle is characterised by the occurrence of two, three or sometimes four waves of follicular development. While dominance is similar to that in B. taurus cattle, maximum diameters of the dominant follicle and CL are smaller than those reported in B. taurus and are probably due to a lower capacity for LH secretion than in B. taurus. Duration of oestrus is approximately 10 h and the interval from oestrus to ovulation is about 27 h. However, the variability in response to prostaglandin F2alpha (PGF) treatments and the difficulty for oestrus detection in B. indicus cattle have limited the widespread application of artificial insemination (AI) and emphasizes the need for treatments that control follicular development and ovulation. Follicular-wave development in B. indicus cattle can be controlled mechanically by ultrasound-guided follicle ablation, or hormonally by treatments with GnRH or oestradiol and progestogen/progesterone in combination. Treatments with GnRH plus PGF and a second GnRH (synchronization protocol known as Ovsynch) or oestradiol benzoate (known as GPE) have resulted in acceptable pregnancy rates after fixed-time AI (FTAI) in cycling

  14. Development and Evolution of Dentition Pattern and Tooth Order in the Skates And Rays (Batoidea; Chondrichthyes)

    PubMed Central

    Underwood, Charlie J.; Johanson, Zerina; Welten, Monique; Metscher, Brian; Rasch, Liam J.; Fraser, Gareth J.; Smith, Moya Meredith

    2015-01-01

    Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the

  15. Development and evolution of dentition pattern and tooth order in the skates and rays (batoidea; chondrichthyes).

    PubMed

    Underwood, Charlie J; Johanson, Zerina; Welten, Monique; Metscher, Brian; Rasch, Liam J; Fraser, Gareth J; Smith, Moya Meredith

    2015-01-01

    Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the

  16. Development and evolution of dentition pattern and tooth order in the skates and rays (batoidea; chondrichthyes).

    PubMed

    Underwood, Charlie J; Johanson, Zerina; Welten, Monique; Metscher, Brian; Rasch, Liam J; Fraser, Gareth J; Smith, Moya Meredith

    2015-01-01

    Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the

  17. Microspot target development with seeded and patterned plasma polymers

    SciTech Connect

    Letts, S.A.; Miller, D.E.; Corley, R.A.; Tillotson, T.M.; Witt, L.A.

    1984-12-10

    A new class of targets for laser fusion experiments was fabricated using plasma-deposition and etching technology. Plasma polymer coatings seeded with silicon or sulfur were deposited as 300..mu..m diameter microspots inside holes of equal diameter in a pure hydrocarbon polymer film. The target was designed to study large-scale plasma instabilities and measure the temperature and density histories of laser induced plasmas. The microspot target required three new development: freestanding stress-free CH films, technology to define and form holes in CH films, and development of seeded films deposited as 300..mu..m diameter discs, nested tightly in the precision holes. Hydrocarbon films were deposited by plasma polymerization or by solution casting (polystyrene in dichloromethane) onto potassium-chloide-coated glass slides. Holes were defined either by masking with a 300..mu..m diameter disc or by reactive ion etching through a washer mask. Sulfur or silicon seeded CH polymer microspots were deposited through a mask using plasma polymerization. Seeded polymer films were prepared with compositions as high as 12 atomic percent, with most diagnostic targets made with 2 a/o. Silicon seeded polymers, when deposited at 750 mtorr (100 Pa) pressure, wer transparent and colorless.

  18. Zebrafish Craniofacial Development: A Window into Early Patterning

    PubMed Central

    Mork, Lindsey; Crump, Gage

    2016-01-01

    The formation of the face and skull involves a complex series of developmental events mediated by cells derived from the neural crest, endoderm, mesoderm, and ectoderm. Although vertebrates boast an enormous diversity of adult facial morphologies, the fundamental signaling pathways and cellular events that sculpt the nascent craniofacial skeleton in the embryo have proven to be highly conserved from fish to man. The zebrafish Danio rerio, a small freshwater cyprinid fish from eastern India, has served as a popular model of craniofacial development since the 1990s. Unique strengths of the zebrafish model include a simplified skeleton during larval stages, access to rapidly developing embryos for live imaging, and amenability to transgenesis and complex genetics. In this chapter, we describe the anatomy of the zebrafish craniofacial skeleton; its applications as models for the mammalian jaw, middle ear, palate, and cranial sutures; the superior imaging technology available in fish that has provided unprecedented insights into the dynamics of facial morphogenesis; the use of the zebrafish to decipher the genetic underpinnings of craniofacial biology; and finally a glimpse into the most promising future applications of zebrafish craniofacial research. PMID:26589928

  19. Zebrafish Craniofacial Development: A Window into Early Patterning.

    PubMed

    Mork, Lindsey; Crump, Gage

    2015-01-01

    The formation of the face and skull involves a complex series of developmental events mediated by cells derived from the neural crest, endoderm, mesoderm, and ectoderm. Although vertebrates boast an enormous diversity of adult facial morphologies, the fundamental signaling pathways and cellular events that sculpt the nascent craniofacial skeleton in the embryo have proven to be highly conserved from fish to man. The zebrafish Danio rerio, a small freshwater cyprinid fish from eastern India, has served as a popular model of craniofacial development since the 1990s. Unique strengths of the zebrafish model include a simplified skeleton during larval stages, access to rapidly developing embryos for live imaging, and amenability to transgenesis and complex genetics. In this chapter, we describe the anatomy of the zebrafish craniofacial skeleton; its applications as models for the mammalian jaw, middle ear, palate, and cranial sutures; the superior imaging technology available in fish that has provided unprecedented insights into the dynamics of facial morphogenesis; the use of the zebrafish to decipher the genetic underpinnings of craniofacial biology; and finally a glimpse into the most promising future applications of zebrafish craniofacial research.

  20. Flux of transcript patterns during soybean seed development

    PubMed Central

    2010-01-01

    Background To understand gene expression networks leading to functional properties of the soybean seed, we have undertaken a detailed examination of soybean seed development during the stages of major accumulation of oils, proteins, and starches, as well as the desiccating and mature stages, using microarrays consisting of up to 27,000 soybean cDNAs. A subset of these genes on a highly-repetitive 70-mer oligonucleotide microarray was also used to support the results. Results It was discovered that genes related to cell growth and maintenance processes, as well as energy processes like photosynthesis, decreased in expression levels as the cotyledons approached the mature, dry stage. Genes involved with some storage proteins had their highest expression levels at the stage of highest fresh weight. However, genes encoding many transcription factors and DNA binding proteins showed higher expression levels in the desiccating and dry seeds than in most of the green stages. Conclusions Data on 27,000 cDNAs have been obtained over five stages of soybean development, including the stages of major accumulation of agronomically-important products, using two different types of microarrays. Of particular interest are the genes found to peak in expression at the desiccating and dry seed stages, such as those annotated as transcription factors, which may indicate the preparation of pathways that will be needed later in the early stages of imbibition and germination. PMID:20181280

  1. The Nature and Process of Development in Averaged Visually Evoked Potentials: Discussion on Pattern Structure.

    ERIC Educational Resources Information Center

    Izawa, Shuji; Mizutani, Tohru

    This paper examines the development of visually evoked EEG patterns in retarded and normal subjects. The paper focuses on the averaged visually evoked potentials (AVEP) in the central and occipital regions of the brain in eyes closed and eyes open conditions. Wave pattern, amplitude, and latency are examined. The first section of the paper reviews…

  2. Developing Pre-Algebraic Thinking in Generalizing Repeating Pattern Using SOLO Model

    ERIC Educational Resources Information Center

    Lian, Lim Hooi; Yew, Wun Thiam

    2011-01-01

    In this paper, researchers discussed the application of the generalization perspective in helping the primary school pupils to develop their pre-algebraic thinking in generalizing repeating pattern. There are two main stages of the generalization perspective had been adapted, namely investigating and generalizing the pattern. Since the Biggs and…

  3. Video-Sharing Websites: Tools for Developing Pattern Languages in Children

    ERIC Educational Resources Information Center

    An, Heejung; Seplocha, Holly

    2010-01-01

    Children and their families and teachers use video-sharing websites for new types of learning and information sharing. With the expansion of the World Wide Web, the ability to freely exchange pattern-based information has grown exponentially. As noted by Alexander, "pattern language development" is a process in which communities freely share…

  4. Dietary Patterns and Body Mass Index in Children with Autism and Typically Developing Children

    ERIC Educational Resources Information Center

    Evans, E. Whitney; Must, Aviva; Anderson, Sarah E.; Curtin, Carol; Scampini, Renee; Maslin, Melissa; Bandini, Linda

    2012-01-01

    To determine whether dietary patterns (juice and sweetened non-dairy beverages, fruits, vegetables, fruits and vegetables, snack foods, and kid's meals) and associations between dietary patterns and body mass index (BMI) differed between 53 children with autism spectrum disorders (ASD) and 58 typically developing children, ages 3-11, multivariate…

  5. Simple Process-Based Simulators for Generating Spatial Patterns of Habitat Loss and Fragmentation: A Review and Introduction to the G-RaFFe Model

    PubMed Central

    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

  6. Simple process-based simulators for generating spatial patterns of habitat loss and fragmentation: a review and introduction to the G-RaFFe model.

    PubMed

    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

  7. Elucidating the role of topological pattern discovery and support vector machine in generating predictive models for Indian summer monsoon rainfall

    NASA Astrophysics Data System (ADS)

    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.

  8. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    NASA Astrophysics Data System (ADS)

    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.

  9. Generation of butterfly wing eyespot patterns: a model for morphological determination of eyespot and parafocal element.

    PubMed

    Otaki, Joji M

    2011-11-01

    The determination of color patterns of butterfly wing eyespots has been explained by the morphogen concentration gradient model. The induction model has been proposed recently as a more realistic alternative, in which the eyespot-specifying signal does not depend entirely on focal activity. However, this model requires further elaboration and supporting evidence to be validated. Here, I examined various color patterns of nymphalid butterflies to propose the mechanics of the induction model. Based on cases in which an eyespot light ring is identical to the background in color, I propose that eyespots are fundamentally composed of dark rings and non-dark "background" spaces between them. In the induction model, the dark-ring-inducing signal that is released from a prospective eyespot focus (the primary organizing center) as a slow-moving wave effects both selfenhancement and peripheral induction of the dark-ring-inhibitory signal at the secondary organizing centers, resulting in an eyespot that has alternate dark and light rings. Moreover, there are cases in which an unseen "imaginary light ring" surrounds an eyespot proper and in which PFEs are integrated into the eyespot. It appears that PFEs constitute a periodic continuum of eyespot dark rings; thus, a background space between the eyespot and a PFE is mechanistically equivalent to eyespot light rings. The eyespot dark-ring-inducing signals and PFE-inducing signal are likely to be identical in quality, but released at different times from the same organizing center. Computer simulations based on the reaction-diffusion system support the feasibility of the induction model. PMID:22035304

  10. Generation of butterfly wing eyespot patterns: a model for morphological determination of eyespot and parafocal element.

    PubMed

    Otaki, Joji M

    2011-11-01

    The determination of color patterns of butterfly wing eyespots has been explained by the morphogen concentration gradient model. The induction model has been proposed recently as a more realistic alternative, in which the eyespot-specifying signal does not depend entirely on focal activity. However, this model requires further elaboration and supporting evidence to be validated. Here, I examined various color patterns of nymphalid butterflies to propose the mechanics of the induction model. Based on cases in which an eyespot light ring is identical to the background in color, I propose that eyespots are fundamentally composed of dark rings and non-dark "background" spaces between them. In the induction model, the dark-ring-inducing signal that is released from a prospective eyespot focus (the primary organizing center) as a slow-moving wave effects both selfenhancement and peripheral induction of the dark-ring-inhibitory signal at the secondary organizing centers, resulting in an eyespot that has alternate dark and light rings. Moreover, there are cases in which an unseen "imaginary light ring" surrounds an eyespot proper and in which PFEs are integrated into the eyespot. It appears that PFEs constitute a periodic continuum of eyespot dark rings; thus, a background space between the eyespot and a PFE is mechanistically equivalent to eyespot light rings. The eyespot dark-ring-inducing signals and PFE-inducing signal are likely to be identical in quality, but released at different times from the same organizing center. Computer simulations based on the reaction-diffusion system support the feasibility of the induction model.

  11. Progress in updatable photorefractive polymer-based holographic displays via direct optical writing of computer-generated fringe patterns

    NASA Astrophysics Data System (ADS)

    Jolly, Sundeep; Barabas, James; Smalley, Daniel; Bove, V. Michael

    2013-03-01

    We have previously introduced an architecture for updatable photorefractive holographic display based around direct fringe writing of computer-generated holographic fringe patterns. In contrast to interference-based stereogram techniques for hologram exposure in photorefractive polymer (PRP) materials, the direct fringe writing architecture simplifies system design, reduces system footprint and cost, and offers greater affordances over the types of holographic images that can be recorded. In this paper, motivations and goals for employing a direct fringe writing architecture for photorefractive holographic imagers are reviewed, new methods for PRP exposure by micro-optical fields generated via spatial light modulation and telecentric optics are described, and resulting holographic images are presented and discussed. Experimental results are reviewed in the context of theoretical indicators for system performance.

  12. Phyletic patterns of early development in gastropod molluscs.

    PubMed

    Lindberg, David R; Guralnick, Robert P

    2003-01-01

    Cell lineage data for 30 exemplar gastropod taxa representing all major subclades and the outgroup Polyplacophora were examined for phylogenetic signal using cladistic analysis. Most cell lineages show phyletic trends of acceleration or retardation relative to the outgroup and more basal ingroup taxa, and when coded this variation is phylo-genetically informative. PAUP analyses of a cell lineage data set under three sets of character ordering assumptions produced similar tree topologies. The topologies of the strict consensus trees for both ordered and Dollo (near irreversibility of character transformations) character assumptions were similar, whereas the unordered character assumption recovers the least phyletic information. The cell lineage cladograms are also in agreement with the fossil record of the timing and sequence of gastropod subclade origination. A long branch lies between the Patellogastropoda+Vetigastropoda grade and the Neritopsina+Apogastropoda clade. The geological timing of this long branch is correlated with the first large-scale terrestrially derived eutrophication of the near-shore marine habitat, and one possible explanation for this branch may be a developmental shift associated with the evolution of feeding larvae in response to the more productive conditions in the near-shore water column. Although character transformations are highly ordered in this data set, developmental rate characters (like all other morphological and molecular characters) are also subject to homoplasy. Finally, this study further supports the hypothesis that early development of gastropod molluscs has conserved a strong phyletic signal for about half a billion years. PMID:12950628

  13. Patterns of mortality in second generation Irish living in England and Wales: longitudinal study.

    PubMed Central

    Harding, S.; Balarajan, R.

    1996-01-01

    OBJECTIVE--To examine the mortality of second generation Irish living in England and Wales. DESIGN--Longitudinal study of 1% of the population of England and Wales (longitudinal study by the Office of Population Censuses and Surveys (now the Office for National Statistics)) followed up from 1971 to 1989. SUBJECTS--3075 men and 3233 women aged 15 and over in 1971. MAIN OUTCOME MEASURES--Age and sex specific standardised mortality ratios for all causes, cancers, coronary heart disease, cerebrovascular diseases, respiratory diseases, and injuries and poisonings. Deaths were also analysed by socioeconomic indicators. RESULTS--786 deaths were traced to men and 762 to women. At working ages (men, aged 15-64; women, 15-59) the mortality of men (standardised mortality ratio 126) and women (129) was significantly higher than that of all men and all women. At ages 15-44, relative disadvantages were even greater both for men (145) and for women (164). Mortality was raised for most major causes of death. Significant excess mortality from cancers was seen for men of working age (132) and for women aged 60 and over (122). At working ages mortality of the second generation Irish in every social class and in the categories of car access and housing tenure was higher than that of all men and all women in the corresponding categories. Adjusting for these socioeconomic indicators did not explain the excess mortality. CONCLUSION--Mortality of second generation Irish men and women was higher than that of all men and all women and for most major causes of death. While socioeconomic factors remain important, cultural and lifestyle factors are likely to contribute to this adverse mortality. PMID:8646095

  14. Laboratory development of permethrin resistance and cross-resistance pattern of Culex quinquefasciatus to other insecticides.

    PubMed

    Ramkumar, Govindaraju; Shivakumar, Muthugoundar S

    2015-07-01

    Resistance of mosquitoes to insecticides is a growing concern in India. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programs mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. In the present study, we evaluate the permethrin resistance and cross-resistance pattern of several insecticides in Culex quinquefasciatus mosquitoes. After 10 generation of selection with permethrin, the LC50 value for both larvae and adult Cx. quinquefasciatus was increased by 17.3- and 17.1-folds compared with susceptible strain. Detoxification enzyme profiles and native PAGE electrophoresis of esterase isoenzyme further revealed that esterase and CytP450 may be involved in permethrin resistance (PerRes) strain compared with susceptible strain. In addition to cross-resistance, study revealed that high resistance to cypermethrin (RR = 6.3, 8.8-folds). This study provided important information for understanding permethrin resistance and facilitating a better strategy for the management of resistance. These studies conclude that a strong foundation for further study of permethrin resistance mechanisms observed in Cx. quinquefasciatus mosquitoes.

  15. Direct patterning of vortex generators on a fiber tip using a focused ion beam.

    PubMed

    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.

  16. Development of a perturbation generator for vortex stability studies

    NASA Technical Reports Server (NTRS)

    Riester, J. E.; Ash, Robert L.

    1991-01-01

    Theory predicts vortex instability when subjected to certain types of disturbances. It was desired to build a device which could introduce controlled velocity perturbations into a trailing line vortex in order to study the effects on stability. A perturbation generator was designed and manufactured which can be attached to the centerbody of an airfoil type vortex generator. Details of design tests and manufacturing of the perturbation generator are presented. The device produced controlled perturbation with frequencies in excess of 250 Hz. Preliminary testing and evaluation of the perturbation generator performance was conducted in a 4 inch cylindrical pipe. Observations of vortex shedding frequencies from a centerbody were measured. Further evaluation with the perturbation generator attached to the vortex generator in a 2 x 3 foot wind tunnel were also conducted. Hot-wire anemometry was used to confirm the perturbation generator's ability to introduce controlled frequency fluctuations. Comparison of the energy levels of the disturbances in the vortex core was made between locations 42 chord lengths and 15 chord lengths downstream.

  17. The over time development of chronic illness self-management patterns: a longitudinal qualitative study

    PubMed Central

    2013-01-01

    Background There currently exists a vast amount of literature concerning chronic illness self-management, however the developmental patterns and sustainability of self-management over time remain largely unknown. This paper aims to describe the patterns by which different chronic illness self-management behaviors develop and are maintained over time. Method Twenty-one individuals newly diagnosed with chronic illnesses (e.g., diabetes, rheumatism, ischemic heart disease, multiple sclerosis, chronic renal disease, inflammatory bowel disease) were repeatedly interviewed over two-and-a-half years. The interviews were conducted in Sweden from 2006 to 2008. A total of 81 narrative interviews were analyzed with an interpretive description approach. Results The participants’ self-management behaviors could be described in four different developmental patterns: consistent, episodic, on demand, and transitional. The developmental patterns were related to specific self-management behaviors. Most participants took long-term medications in a consistent pattern, whereas exercise was often performed according to an episodic pattern. Participants managed health crises (e.g., angina, pain episodes) according to an on demand pattern and everyday changes due to illness (e.g., adaptation of work and household activities) according to a transitional pattern. All of the participants used more than one self-management pattern. Conclusion The findings show that self-management does not develop as one uniform pattern. Instead different self-management behaviors are enacted in different patterns. Therefore, it is likely that self-management activities require support strategies tailored to each behavior’s developmental pattern. PMID:23647658

  18. DEVELOPMENT OF A NEXT-GENERATION ANTIMICROBIAL WOUND DRESSING.

    PubMed

    Metcalf, Daniel; Parsons, David; Bowler, I Philip

    2016-03-01

    Delayed wound healing due to infection is a burden on healthcare systems, and the patient and caregiver alike. An emerging factor in infection and delayed healing is the presence development of biofilm in wounds. Biofilm is communities of microorganisms, protected by an extracellular matrix of slime in the wound, which can tolerate host defences and applied antimicrobials such as antibiotics or antimicrobial dressings. A growing evidence base exists suggesting that biofilm exists in a majority of chronic wounds, and can be a precursor to infection while causing delayed healing itself. In vivo models have demonstrated that the inflammatory, granulation and epithelialization processes of normal wound healing are impaired by biofilm presence. The challenge in the development of a new antimicrobial wound dressing was to make standard antimicrobial agents more effective against biofilm, and this was answered following extensive biofilm research and testing. A combination of metal chelator, surfactant and pH control displayed highly synergistic anti-biofilm action with 1.2% ionic silver in a carboxymethylcellulose dressing. Its effectiveness was challenged and proven in complex in vitro and in vivo wound biofilm models, followed by clinical safety and performance demonstrations in a 42-patient study and 113 clinical evaluations. Post-market surveillance was conducted on the commercially available dressing, and in a 112-case evaluation, the dressing was shown to effectively manage exudate and suspected biofilm while shifting difficult-to-heal wounds onto healing trajectories, after an average of 4 weeks of new dressing use in otherwise standard wound care protocols. This was accompanied by a low frequency of dressing related adverse events. In a second evaluation, clinical signs of infection and wound dimension data, before and after the evaluations, were also available. Following an average of 5.4 weeks of dressing use, all signs of clinical infection were reduced, from

  19. DEVELOPMENT OF A NEXT-GENERATION ANTIMICROBIAL WOUND DRESSING.

    PubMed

    Metcalf, Daniel; Parsons, David; Bowler, I Philip

    2016-03-01

    Delayed wound healing due to infection is a burden on healthcare systems, and the patient and caregiver alike. An emerging factor in infection and delayed healing is the presence development of biofilm in wounds. Biofilm is communities of microorganisms, protected by an extracellular matrix of slime in the wound, which can tolerate host defences and applied antimicrobials such as antibiotics or antimicrobial dressings. A growing evidence base exists suggesting that biofilm exists in a majority of chronic wounds, and can be a precursor to infection while causing delayed healing itself. In vivo models have demonstrated that the inflammatory, granulation and epithelialization processes of normal wound healing are impaired by biofilm presence. The challenge in the development of a new antimicrobial wound dressing was to make standard antimicrobial agents more effective against biofilm, and this was answered following extensive biofilm research and testing. A combination of metal chelator, surfactant and pH control displayed highly synergistic anti-biofilm action with 1.2% ionic silver in a carboxymethylcellulose dressing. Its effectiveness was challenged and proven in complex in vitro and in vivo wound biofilm models, followed by clinical safety and performance demonstrations in a 42-patient study and 113 clinical evaluations. Post-market surveillance was conducted on the commercially available dressing, and in a 112-case evaluation, the dressing was shown to effectively manage exudate and suspected biofilm while shifting difficult-to-heal wounds onto healing trajectories, after an average of 4 weeks of new dressing use in otherwise standard wound care protocols. This was accompanied by a low frequency of dressing related adverse events. In a second evaluation, clinical signs of infection and wound dimension data, before and after the evaluations, were also available. Following an average of 5.4 weeks of dressing use, all signs of clinical infection were reduced, from

  20. Practical performance and enabling technologies in immersion scanners for the double patterning generation

    NASA Astrophysics Data System (ADS)

    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