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Sample records for aav-tau mediates pyramidal

  1. Cholinergic-mediated IP3-receptor activation induces long-lasting synaptic enhancement in CA1 pyramidal neurons

    Fernández de Sevilla, D.; Núñez Molina, Ángel; Borde, M.; Malinow, R.; Buño, Washinton

    2008-01-01

    Cholinergic-glutamatergic interactions influence forms of synaptic plasticity that are thought to mediate memory and learning. We tested in vitro the induction of long-lasting synaptic enhancement at Schaffer collaterals by acetylcholine (ACh) at the apical dendrite of CA1 pyramidal neurons and in vivo by stimulation of cholinergic afferents. In vitro ACh induced a Ca2+ wave and synaptic enhancement mediated by insertion of AMPA receptors in spines. Activation of muscarinic ACh receptors (mAC...

  2. Computational modeling reveals dendritic origins of GABA(A-mediated excitation in CA1 pyramidal neurons.

    Naomi Lewin

    Full Text Available GABA is the key inhibitory neurotransmitter in the adult central nervous system, but in some circumstances can lead to a paradoxical excitation that has been causally implicated in diverse pathologies from endocrine stress responses to diseases of excitability including neuropathic pain and temporal lobe epilepsy. We undertook a computational modeling approach to determine plausible ionic mechanisms of GABA(A-dependent excitation in isolated post-synaptic CA1 hippocampal neurons because it may constitute a trigger for pathological synchronous epileptiform discharge. In particular, the interplay intracellular chloride accumulation via the GABA(A receptor and extracellular potassium accumulation via the K/Cl co-transporter KCC2 in promoting GABA(A-mediated excitation is complex. Experimentally it is difficult to determine the ionic mechanisms of depolarizing current since potassium transients are challenging to isolate pharmacologically and much GABA signaling occurs in small, difficult to measure, dendritic compartments. To address this problem and determine plausible ionic mechanisms of GABA(A-mediated excitation, we built a detailed biophysically realistic model of the CA1 pyramidal neuron that includes processes critical for ion homeostasis. Our results suggest that in dendritic compartments, but not in the somatic compartments, chloride buildup is sufficient to cause dramatic depolarization of the GABA(A reversal potential and dominating bicarbonate currents that provide a substantial current source to drive whole-cell depolarization. The model simulations predict that extracellular K(+ transients can augment GABA(A-mediated excitation, but not cause it. Our model also suggests the potential for GABA(A-mediated excitation to promote network synchrony depending on interneuron synapse location - excitatory positive-feedback can occur when interneurons synapse onto distal dendritic compartments, while interneurons projecting to the perisomatic

  3. Centered Pyramids

    Brigger, P.; F. Müller; Illgner, K.; Unser, M.

    1999-01-01

    Quadtree-like pyramids have the advantage of resulting in a multiresolution representation where each pyramid node has four unambiguous parents. Such a centered topology guarantees a clearly defined up-projection of labels. This concept has been successfully and extensively used in applications of contour detection, object recognition and segmentation. Unfortunately, the quadtree-like type of pyramid has poor approximation powers because of the employed piecewise-constant image model. This pa...

  4. Pyramids of QTLs enhance host–plant resistance and Bt-mediated resistance to leaf-chewing insects in soybean

    Ortega, María A.; All, John N.; Boerma, H. Roger; Parrott, Wayne A.

    2016-01-01

    Key message QTL-M and QTL-E enhance soybean resistance to insects. Pyramiding these QTLs with cry1Ac increases protection against Bt-tolerant pests, presenting an opportunity to effectively deploy Bt with host–plant resistance genes. Abstract Plant resistance to leaf-chewing insects minimizes the need for insecticide applications, reducing crop production costs and pesticide concerns. In soybean [Glycine max (L.) Merr.], resistance to a broad range of leaf-chewing insects is found in PI 22935...

  5. AAV vector-mediated overexpression of CB1 cannabinoid receptor in pyramidal neurons of the hippocampus protects against seizure-induced excitoxicity.

    Stephan Guggenhuber

    Full Text Available The CB1 cannabinoid receptor is the most abundant G-protein coupled receptor in the brain and a key regulator of neuronal excitability. There is strong evidence that CB1 receptor on glutamatergic hippocampal neurons is beneficial to alleviate epileptiform seizures in mouse and man. Therefore, we hypothesized that experimentally increased CB1 gene dosage in principal neurons would have therapeutic effects in kainic acid (KA-induced hippocampal pathogenesis. Here, we show that virus-mediated conditional overexpression of CB1 receptor in pyramidal and mossy cells of the hippocampus is neuroprotective and moderates convulsions in the acute KA seizure model in mice. We introduce a recombinant adeno-associated virus (AAV genome with a short stop element flanked by loxP sites, for highly efficient attenuation of transgene expression on the transcriptional level. The presence of Cre-recombinase is strictly necessary for expression of reporter proteins or CB1 receptor in vitro and in vivo. Transgenic CB1 receptor immunoreactivity is targeted to glutamatergic neurons after stereotaxic delivery of AAV to the dorsal hippocampus of the driver mice NEX-cre. Increased CB1 receptor protein levels in hippocampal lysates of AAV-treated Cre-mice is paralleled by enhanced cannabinoid-induced G-protein activation. KA-induced seizure severity and mortality is reduced in CB1 receptor overexpressors compared with AAV-treated control animals. Neuronal damage in the hippocampal CA3 field is specifically absent from AAV-treated Cre-transgenics, but evident throughout cortical areas of both treatment groups. Our data provide further evidence for a role of increased CB1 signaling in pyramidal hippocampal neurons as a safeguard against the adverse effects of excessive excitatory network activity.

  6. Clustering of population pyramids

    Kejžar, Nataša; Korenjak-Černe, Simona; Batagelj, Vladimir

    2015-01-01

    Population pyramid is a very popular presentation of the age-sex distribution of the human population of a particular region. The shape of the pyramid shows many demographic, social, and political characteristics of the time and the region. In the paper results of hierarchical clustering of the world countries based on population pyramids are presented. Special attention is given to the shapes of the pyramids. The changes of the pyramids' shapes, and also changes of the countries inside main ...

  7. Clustering of population pyramids:

    Batagelj, Vladimir; Kejžar, Nataša; Korenjak-Černe, Simona

    2008-01-01

    Population pyramid is a very popular presentation of the age-sex distribution of the human population of a particular region. The shape of the pyramid shows many demographic, social, and political characteristics of the time and the region. In the paper results of hierarchical clustering of the world countries based on population pyramids are presented. Special attention is given to the shapes of the pyramids. The changes of the pyramids' shapes, and also changes of the countries inside main ...

  8. Pyramid Comet Sampler Project

    National Aeronautics and Space Administration — Based on the sampling requirements, we propose an Inverted Pyramid sampling system. Each face of the pyramid includes a cutting blade which is independently...

  9. Numerical integration over pyramids

    Chen, Ch.; Křížek, M.; Liu, L

    2013-01-01

    Pyramidal elements are often used to connect tetrahedral and hexahedral elements in the finite element method. In this paper we derive three new higher order numerical cubature formulae for pyramidal elements.

  10. The Corporate Pyramid Fable

    Steven A. Bank and Brian R. Cheffins

    2010-01-01

    Although corporate pyramids are currently commonplace world-wide and although there have been "noteworthy pyramiders" in American business history, this controversial form of corporate organization is now a rarity in the United States. The conventional wisdom is that corporate pyramids disappeared in the U.S. when New Deal policymakers began taxing dividends paid to corporate shareholders. This version of events is more fable than truth. The introduction of the intercorporate dividend tax did...

  11. The Healthy Eating Pyramid

    Jimmy; Lin

    2007-01-01

    Experts from the Harvard School of Public Health created the Healthy Eating Pyramid.The pyramid is about the links between diet and health and offers useable information to help people make better choices about what to eat. Remember:its base is daily exercise and weight control.

  12. The GLP-1 Receptor Agonist Exendin-4 and Diazepam Differentially Regulate GABAA Receptor-Mediated Tonic Currents in Rat Hippocampal CA3 Pyramidal Neurons.

    Sergiy V Korol

    Full Text Available Glucagon-like peptide-1 (GLP-1 is a metabolic hormone that is secreted in a glucose-dependent manner and enhances insulin secretion. GLP-1 receptors are also found in the brain where their signalling affects neuronal activity. We have previously shown that the GLP-1 receptor agonists, GLP-1 and exendin-4 enhanced GABA-activated synaptic and tonic currents in rat hippocampal CA3 pyramidal neurons. The hippocampus is the centre for memory and learning and is important for cognition. Here we examined if exendin-4 similarly enhanced the GABA-activated currents in the presence of the benzodiazepine diazepam. In whole-cell recordings in rat brain slices, diazepam (1 μM, an allosteric positive modulator of GABAA receptors, alone enhanced the spontaneous inhibitory postsynaptic current (sIPSC amplitude and frequency by a factor of 1.3 and 1.6, respectively, and doubled the tonic GABAA current normally recorded in the CA3 pyramidal cells. Importantly, in the presence of exendin-4 (10 nM plus diazepam (1 μM, only the tonic but not the sIPSC currents transiently increased as compared to currents recorded in the presence of diazepam alone. The results suggest that exendin-4 potentiates a subpopulation of extrasynaptic GABAA receptors in the CA3 pyramidal neurons.

  13. The OER Adoption Pyramid

    Trotter, Henry; Cox, Glenda

    2016-01-01

    This Pyramid was developed in the course of a research paper focusing on why South African academics adopt OER or not. We understood that numerous factors shaped their choices, but it became apparent that some factors were "essential" to OER activity while others were merely "influential". To clarify which factors were required for any type of OER activity, we developed the OER Adoption Pyramid, which consolidates the factors into six hierarchically related categories: acc...

  14. Phasic and tonic type A γ-Aminobutryic acid receptor mediated effect of Withania somnifera on mice hippocampal CA1 pyramidal Neurons

    Janardhan Prasad Bhattarai

    2014-01-01

    Full Text Available Background: In Nepali and Indian system of traditional medicine, Withania somnifera (WS is considered as a rejuvenative medicine to maintain physical and mental health and has also been shown to improve memory consolidation. Objective: In this study, a methanolic extract of WS (mWS was applied on mice hippocampal CA1 neurons to identify the receptors activated by the WS. Materials and Methods: The whole cell patch clamp recordings were performed on CA1 pyramidal neurons from immature mice (7-20 postnatal days. The cells were voltage clamped at -60 mV. Extract of WS root were applied to identify the effect of mWS. Results: The application of mWS (400 ng/μl induced remarkable inward currents (-158.1 ± 28.08 pA, n = 26 on the CA1 pyramidal neurons. These inward currents were not only reproducible but also concentration dependent. mWS-induced inward currents remained persistent in the presence of amino acid receptor blocking cocktail (AARBC containing blockers for the ionotropic glutamate receptors, glycine receptors and voltage-gated Na + channel (Control: -200.3 ± 55.42 pA, AARBC: -151.5 ± 40.58 pA, P > 0.05 suggesting that most of the responses by mWS are postsynaptic events. Interestingly, these inward currents were almost completely blocked by broad GABA A receptor antagonist, bicuculline- 20 μM (BIC (BIC: -1.46 ± 1.4 pA, P < 0.001, but only partially by synaptic GABA A receptor blocker gabazine (1 μM (GBZ: -18.26 ± 4.70 pA, P < 0.01. Conclusion: These results suggest that WS acts on synaptic/extrasynaptic GABA A receptors and may play an important role in the process of memory and neuroprotection via activation of synaptic and extrasynaptic GABA A receptors.

  15. Building the next pyramid

    West, Joseph; Waters, Kevin; Ward, Stephen; Ward, Tia

    2015-01-01

    The results of experimental tests of a novel method for moving large (pyramid construction size) stone blocks by rolling them are presented. The method is implemented by tying 12 identical rods of appropriately chosen radius to the faces of the block forming a rough dodecagon prism. Experiments using a 1,000 kg block show that it can be moved across level open ground with a dynamic coefficient of friction of less than 0.06. This value is a factor of five lower than that obtained for dragging the block, and the best values reported for dragging by others, at 0.3. the results are more dramatic than those obtained on smaller scale experiments on a 29.6 kg block, also reported here. For full scale pyramid blocks, the wooden "rods" woudl need to be posts of order 30 cm in diameter, similar in size to those used as masts on ships in the Nile.

  16. Numerical integration over pyramids

    Chen, Ch.; Křížek, Michal; Liu, L.

    2013-01-01

    Roč. 5, č. 3 (2013), s. 309-320. ISSN 2070-0733 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : reference pyramidal element * nonlinear systems of algebraic equations * Bramble-Hilbert lemma Subject RIV: BA - General Mathematics Impact factor: 0.645, year: 2013 http://www.global-sci.org/aamm/readabs.php?vol=5&no=3&doc=309&year=2013&ppage=320

  17. Imaging the Cheops Pyramid

    Bui, H D

    2012-01-01

    In this book Egyptian Archeology  and Mathematics meet. The author is an expert in theories and applications in Solid Mechanics and Inverse Problems, a former professor at Ecole Polytechnique and now works with Electricité de France on maintenance operations on nuclear power plants. In the Autumn of 1986, after the end of the operation on the King’s chamber conducted under the Technological and Scientific Sponsorship of EDF, to locate a cavity, he was called to solve a mathematical inverse problem, to find the unknown tomb of the King and the density structure of the whole pyramid based on measurements of microgravity made inside and outside of the pyramid. This book recounts the various search operations on the pyramid of Cheops made at the request of the Egyptian and French authorities in 1986-1987. After the premature end of the Cheops operation in the Autumn of 1986, following the fiasco of unsuccessful drillings in the area suspected by both architects G. Dormion and J.P. Goidin and microgravity aus...

  18. Pyramid Lake Renewable Energy Project

    John Jackson

    2008-03-14

    The Pyramid Lake Paiute Tribe is a federally recognized Tribe residing on the Pyramid Lake Reservation in western Nevada. The funding for this project was used to identify blind geothermal systems disconnected from geothermal sacred sites and develop a Tribal energy corporation for evaluating potential economic development for profit.

  19. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  20. Quasi-Convolution Pyramidal Blurring

    Martin Kraus

    2009-12-01

    Full Text Available Efficient image blurring techniques based on the pyramid algorithm can be implemented on modern graphics hardware; thus, image blurring with arbitrary blur width is possible in real time even for large images. However, pyramidal blurring methods do not achieve the image quality provided by convolution filters; in particular, the shape of the corresponding filter kernel varies locally, which potentially results in objectionable rendering artifacts. In this work, a new analysis filter is designed that significantly reduces this variation for a particular pyramidal blurring technique. Moreover, the pyramidal blur algorithm is generalized to allow for a continuous variation of the blur width. Furthermore, an efficient implementation for programmable graphics hardware is presented. The proposed method is named “quasi-convolution pyramidal blurring” since the resulting effect is very close to image blurring based on a convolution filter for many applications.

  1. Correspondences between Pre-pyramids, Pyramids and Robinsonian Dissimilarities

    Bertrand, Patrice; Diatta, Jean; Jean, Diatta

    2013-01-01

    We consider cluster structures in a general setting where they do not necessarily contain all singletons of the ground set. Then we provide a direct proof of the bijection between semi-proper robinsonian dissimilarities and indexed pre-pyramids. This result generalizes its analogue proven by Batbedat in the particular case of definite cluster structures. Moreover, the proposed proof shows that the clusters of the indexed pre-pyramid corresponding to a semi-proper robinsonian dissimilarity are...

  2. The Pyramidal Capacitated Vehicle Routing Problem

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...

  3. The pyramidal capacitated vehicle routing problem

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal...

  4. Interactive Visualization of Graph Pyramids

    Kerren, Andreas

    2006-01-01

    Hierarchies of plane graphs, called graph pyramids, can be used for collecting, storing and analyzing geographical information based on satellite images or other input data. The visualization of graph pyramids facilitates studies about their structure, such as their vertex distribution or height in relation of a specific input image. Thus, a researcher can debug algorithms and ask for statistical information. Furthermore, it improves the better understanding of geographical data, like land...

  5. Pyramidal Cell-Interneuron Interactions Underlie Hippocampal Ripple Oscillations

    Stark, Eran; Roux, Lisa; Eichler, Ronny; Senzai, Yuta; Royer, Sebastien; Buzsáki, György

    2015-01-01

    SUMMARY High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation, frequency control, and spatial coherence of the rhythm are poorly understood. Using multisite optogenetic manipulations in freely behaving rodents, we found that depolarization of a small group of nearby pyramidal cells was sufficient to induce high-frequency oscillations, whereas closed-loop silencing of pyramidal cells or activation of parvalbumin-(PV) or somatostatin-immunoreactive interneurons aborted spontaneously occurring ripples. Focal pharmacological blockade of GABAA receptors abolished ripples. Localized PV inter-neuron activation paced ensemble spiking, and simultaneous induction of high-frequency oscillations at multiple locations resulted in a temporally coherent pattern mediated by phase-locked inter-neuron spiking. These results constrain competing models of ripple generation and indicate that temporally precise local interactions between excitatory and inhibitory neurons support ripple generation in the intact hippocampus. PMID:25033186

  6. A Pyramid Scheme for Particle Physics

    Banks, Tom

    2009-01-01

    We introduce a new model, the Pyramid Scheme, of direct mediation of SUSY breaking, which is compatible with the idea of Cosmological SUSY Breaking (CSB). It uses the trinification scheme of grand unification and avoids problems with Landau poles in standard model gauge couplings. It also avoids problems, which have recently come to light, associated with rapid stellar cooling due to emission of the pseudo Nambu-Goldstone Boson (PNGB) of spontaneously broken hidden sector baryon number. With a certain pattern of R-symmetry breaking masses, a pattern more or less required by CSB, the Pyramid Scheme leads to a dark matter candidate that decays predominantly into leptons, with cross sections compatible with a variety of recent observations. The dark matter particle is not a thermal WIMP but a particle with new strong interactions, produced in the late decay of some other scalar, perhaps the superpartner of the QCD axion, with a reheat temperature in the TeV range. This is compatible with a variety of scenarios f...

  7. Pyramid Lake Task Force : Final report

    US Fish and Wildlife Service, Department of the Interior — The Pyramid Lake Task Force was created to address Pyramid Lake’s recession and recommend possible solutions that would consider both the needs for preserving the...

  8. Contains and Inside relationships within combinatorial Pyramids

    Brun, Luc; Kropatsch, Walter

    2007-01-01

    Irregular pyramids are made of a stack of successively reduced graphs embedded in the plane. Such pyramids are used within the segmentation framework to encode a hierarchy of partitions. The different graph models used within the irregular pyramid framework encode different types of relationships between regions. This paper compares different graph models used within the irregular pyramid framework according to a set of relationships between regions. We also define a new algorithm based on a ...

  9. Fabrication of nanopore on pyramid

    Choi, Seong Soo, E-mail: sscphy2010@gmail.com [Department of Nanoscience and Instrument Center, SunMoon University, Ahsan 336-708 (Korea, Republic of); Park, Myong-Jin; Yamaguchi, Tokutaro [Department of Nanoscience and Instrument Center, SunMoon University, Ahsan 336-708 (Korea, Republic of); Kim, Sung-In; Park, Kyung-Jin [Team for Measurement and Analysis, National Nanofab Center, Daejeon 305-806 (Korea, Republic of); Park, Nam Kyoo [School of Electrical Engineering, Seoul National University, Seoul (Korea, Republic of)

    2014-08-15

    Graphical abstract: - Highlights: • Au nanopores on the apex of the pyramidal structure were fabricated. • The nanopore formations dependent upon the electron currents, the primary electron voltage, and the scan rate were examined. • Nanopore formation using focused ion beam was also investigated. - Abstract: There have been tremendous interests about the fabrication of metallic nanopore due to the ultrafast genome sequencing biosensor capability. In this report, the fabrication of the nanopore on the Au coated SiO{sub 2} pyramid has been examined using various high energy electron beam irradiation and focused ion beam (FIB) milling techniques. The microfabricated Au nano-apertures on pyramid were irradiated with various high energy electron beam and FIB techniques. The formation of the nanopore dependent on the probe current was also examined using electron probe micro-analysis (EPMA). The nanopore on the Au coated SiO{sub 2} pyramid is found to be an Au-Si mixture. The Au nanopore on the crater type hole was also fabricated using FIB Ga ion beam scanning. The shrinking rate was found to be the fastest compared with those fabricated with the other electron beam techniques.

  10. The Base of the Pyramid

    Hutte, E.; Vermeulen, P.A.M.

    2014-01-01

    This chapter provides a brief background to the Base of the Pyramid (BoP) phenomenon. It begins with a discussion on what sets the BoP markets apart from more traditional markets and why companies have not identified them as a business opportunity. The chapter then provides an overview of how attent

  11. A magic pyramid of supergravities

    Anastasiou, A.; Borsten, L.; Duff, M. J.; Hughes, L. J.; Nagy, S.

    2014-04-01

    By formulating = 1, 2, 4, 8, D = 3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in , it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D = 3 supergravities. This was subsequently tied in with the more familiar description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D = 3, 4, 6, 10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D = 3 is the known 4 × 4 magic square, while the higher levels are comprised of a 3 × 3 square in D = 4, a 2 × 2 square in D = 6 and Type II supergravity at the apex in D = 10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also construct a conformal magic pyramid by tensoring conformal supermultiplets in D = 3, 4, 6. The missing entry in D = 10 is suggestive of anexotic theory with G/ H duality structure F 4(4)/Sp(3) × Sp(1).

  12. The Chinese Pyramids and the Sun

    Sparavigna, Amelia Carolina

    2012-01-01

    The Chinese Pyramids are huge ancient burial mounds. In the satellite images we can see some complexes where the main buildings are the pyramidal mounds of an emperor and his empress. Here we discuss a possible sunrise/sunset orientation of these two pyramids on the solstices and equinoxes.

  13. Investigation of the Great Pyramid of Giza.

    Peace, Nigel; And Others

    1997-01-01

    Describes an activity in which geometry and trigonometry are studied using pyramids. Identical model pyramids are constructed from card stock, along with pyramids of different proportions and cuboids to use as controls. Also includes an investigation of some apparently non-scientific claims. (DDR)

  14. Three Types of Network Complexity Pyramid

    FANG; Jin-qing; LI; Yong; LIU; Qiang

    2012-01-01

    <正>Exploring the complexity and diversity of complex networks have been very challenging issues in network science and engineering. Among them exploring the network complexity pyramids (NCP) are one of important expressions in network complexity. So far as we have proposed the three types of the network complexity pyramid (NCP). The first type of NCP is the network model complexity pyramid with

  15. Quantile pyramids for Bayesian nonparametrics

    2009-01-01

    P\\'{o}lya trees fix partitions and use random probabilities in order to construct random probability measures. With quantile pyramids we instead fix probabilities and use random partitions. For nonparametric Bayesian inference we use a prior which supports piecewise linear quantile functions, based on the need to work with a finite set of partitions, yet we show that the limiting version of the prior exists. We also discuss and investigate an alternative model based on the so-called substitut...

  16. LBP and irregular graph pyramids

    Cerman, Martin; González Díaz, Rocío; Kropatsch, Walter

    2015-01-01

    In this paper, a new codification of Local Binary Patterns (LBP) is given using graph pyramids. The LBP code characterizes the topological category (local max, min, slope, saddle) of the gray level landscape around the center region. Given a 2D grayscale image I, our goal is to obtain a simplified image which can be seen as “minimal” representation in terms of topological characterization of I. For this, a method is developed based on merging regions and Minimum Contrast Algorithm.

  17. Pyramidal parent training by peers.

    Neef, N A

    1995-01-01

    This study replicated a pyramidal model of parent training by peers and compared its effects with training by a professional with 26 parents of children with disabilities. A multiple probe design across 3 tiers of parents showed that both types of training produced acquisition, maintenance, and to varying extents, generalization of parents' teaching skills, with concomitant increases in the children's performance in most cases. Improvements were comparable for parents trained by a professiona...

  18. A magic pyramid of supergravities

    Anastasiou, A; Duff, M J; Hughes, L J; Nagy, S

    2013-01-01

    By formulating N = 1, 2, 4, 8, D = 3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in R,C,H,O, it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D = 3 supergravities. This was subsequently tied in with the more familiar R,C,H,O description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D = 3, 4, 6, 10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D = 3 is the known 4x4 magic square, while the higher levels are comprised of a 3x3 square in D = 4, a 2x2 square in D = 6 and Type II supergravity at the apex in D = 10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also c...

  19. An Analysis of Pyramidal Image Fusion Techniques

    Meek, T. R.

    1999-01-01

    This paper discusses the application of multiresolution image fusion techniques to synthetic aperture radar (SAR) and Landsat imagery. Results were acquired through the development and application of image fusion software to test images. The test images were fused using six image fusion techniques that are the combinations from three types of image decomposition algorithms (ratio of low pass [RoLP] pyramids, gradient pyramids, and morphological pyramids) and two types of fusion algorithms (se...

  20. Inside and outside within combinatorial pyramids

    Brun, Luc; Kropatsch, Walter G.

    2005-01-01

    Irregular pyramids are made of a stack of successively reduced graphs embedded in the plane. Such pyramids are often used within the segmentation and the connected component analysis frameworks to detect meaningful objects together with their spatial and topological relationships. The graphs reduced in the pyramid may be region adjacency graphs, dual graphs or combinatorial maps. Using any of these graphs each vertex of a reduced graph encodes a region of the image. Using simple graphs one ed...

  1. Multichannel Texture Segmentation Using Bamberger Pyramids

    Smith, Mark J.T.; Jose Gerardo Rosiles

    2009-01-01

    Abstract A multichannel texture segmentation algorithm is presented based on the image pyramids produced with the Bamberger directional filter bank. An extensive evaluation of Bamberger pyramids and their design parameters is presented. The impact on segmentation performance of factors like the number of pyramid levels, number of directional channels, redundancy and filter specifications is considered. The proposed system is shown to provide some of the best results reported to date when comp...

  2. The Emergence of Corporate Pyramids in China

    Fan, Joseph P.H.; T.J. Wong; Zhang, Tianyu

    2006-01-01

    We examine the pyramidal ownership structure of a large sample of newly listed Chinese companies controlled by local governments or private entrepreneurs. Both types of the owners use layers of intermediate companies to control their firms. However, their pyramiding behaviors are likely affected by different property rights constraints. Local governments are constrained by the Chinese laws prohibiting free transfer of state ownership. Pyramiding allows them to credibly decentralize their firm...

  3. Urban Public Health: Is There a Pyramid?

    Meirong Su

    2013-01-01

    Full Text Available Early ecologists identified a pyramidal trophic structure in terms of number, biomass and energy transfer. In 1943, the psychologist Maslow put forward a pyramid model to describe layers of human needs. It is indicated that the pyramid principle is universally applicable in natural, humanistic and social disciplines. Here, we report that a pyramid structure also exists in urban public health (UPH. Based on 18 indicators, the UPH states of four cities (Beijing, Tokyo, New York, and London are compared from the point of view of five aspects, namely physical health, living conditions, social security, environmental quality, and education and culture. A pyramid structure was found in each city when focusing on 2000–2009 data. The pyramid of Beijing is relatively similar to that of Tokyo, and the pyramids of New York and London are similar to each other. A general development trend in UPH is proposed and represented by different pyramid modes. As a basic conjecture, the UPH pyramid model can be verified and developed with data of more cities over a longer period, and be used to promote healthy urban development.

  4. Update on the Pyramid Scheme

    Banks, Tom

    2012-01-01

    We summarize recent work in which we attempt to make a consistent model of LHC physics, from the Pyramid Scheme. The models share much with the NMSSM, in particular, enhanced tree level contributions to the Higgs mass and a preference for small tan {\\beta}. There are 3 different singlet fields, and a new strongly coupled gauge theory, so the constraints of perturbative unification are quite different. We outline our general approach to the model, which contains a Kahler potential for three of the low energy fields, which is hard to calculate. Detailed calculations, based on approximations to the Kahler potential, will be presented in a future publication.

  5. The cradle of pyramids in satellite images

    Sparavigna, Amelia Carolina

    2011-01-01

    We propose the use of image processing to enhance the Google Maps of some archaeological areas of Egypt. In particular we analyse that place which is considered the cradle of pyramids, where it was announced the discovery of a new pyramid by means of an infrared remote sensing.

  6. The Pyramid Phasing Sensor (PYPS)

    Pinna, E.; Quirós-Pacheco­, F.; Esposito, S.; Puglisi, A.; Stefanini, P.

    2008-07-01

    PYPS is the pyramid wavefront sensor for the phasing and alignment of segmented mirrors developed in the framework of the Active Phase Experiment (APE). In this paper we will present the PYPS opto-mechanical design, and report the experimental results obtained in the Arcetri laboratories prior to its integration in the main APE bench. A piston-correction closed loop was performed under the presence of emulated turbulence (D/r0=33 @ 700nm and V/D=1.9Hz), achieving a final piston error of 10 nm rms in wavefront. Two filtering techniques were developed to average out faster the atmospheric disturbance reducing the required co-phasing time by two orders of magnitude. We will also present the first experimental results obtained with a synthetic interaction matrix attaining a final piston error of the same order of magnitude.

  7. FABRIC DEFECT DETECTION USING STEERABLE PYRAMID

    S. Mythili

    2011-05-01

    Full Text Available In this paper, a novel idea is proposed for fabric defect detection. De- fects are detected in the fabric using steerable pyramid along with a defect detection algorithm. Various steerable pyramid of four size 256*256, 128*128, 64*64, 32*32 and with four orientation bands 00,450, 900, 1350 are used. Utilizing a Steerable pyramid proved ade- quate in the representation of fabric images in multi-scale and multi- orientations; thus allowing defect detection algorithms to run more effectively. Defect detection algorithm identifies and locates the im- perfection in the defective sample using the statistics mean and stan- dard deviation. This statistics represents the relative amount of inten- sity in the texture and is sufficient to measure defects in the current model .The obtained result are compared with the existing methods wavelet based system and with Gaussian and Laplacian pyramid.

  8. Simulation of gene pyramiding in Drosophila melanogaster

    2008-01-01

    Gene pyramiding has been successfully practiced in plant breeding for developing new breeds or lines in which favorable genes from several different lines were integrated.But it has not been used in animal breeding,and some theoretical investigation and simulation analysis with respect to its strategies,feasibility and efficiency are needed before it can be implemented in animals.In this study,we used four different pure fines of Drosophila melanogaster,each of which is homozygous at a specific mutant gene with a visible effect on phenotype,to simulate the gene pyramiding process and analyze the duration and population size required in different pyramiding strategies.We finally got the ideal individuals,which are homozygous at the four target genes simultaneously.This study demonstrates that gene pyramiding is feasible in animal breeding and the interaction between genes may affect the final results.

  9. Pyramidal micromirrors for microsystems and atom chips

    Trupke, M.; Ramirez-Martinez, F.; Curtis, E. A.; Ashmore, J. P.; Eriksson, S.; Hinds, E. A.; Moktadir, Z.; Gollasch, C.; Kraft, M.; Vijaya Prakash, G.; Baumberg, J. J.

    2006-02-01

    Concave pyramids are created in the (100) surface of a silicon wafer by anisotropic etching in potassium hydroxide. High quality micromirrors are then formed by sputtering gold onto the smooth silicon (111) faces of the pyramids. These mirrors show great promise as high quality optical devices suitable for integration into micro-optoelectromechanical systems and atom chips. We have shown that structures of this shape can be used to laser-cool and hold atoms in a magneto-optical trap.

  10. Novel nootropic dipeptide Noopept increases inhibitory synaptic transmission in CA1 pyramidal cells.

    Kondratenko, Rodion V; Derevyagin, Vladimir I; Skrebitsky, Vladimir G

    2010-05-31

    Effects of newly synthesized nootropic and anxiolytic dipeptide Noopept on inhibitory synaptic transmission in hippocampal CA1 pyramidal cells were investigated using patch-clamp technique in whole-cell configuration. Bath application of Noopept (1 microM) significantly increased the frequency of spike-dependant spontaneous IPSCs whereas spike-independent mIPSCs remained unchanged. It was suggested that Noopept mediates its effect due to the activation of inhibitory interneurons terminating on CA1 pyramidal cells. Results of current clamp recording of inhibitory interneurons residing in stratum radiatum confirmed this suggestion. PMID:20382202

  11. Pascal Pyramids, Pascal Hyper-Pyramids and a Bilateral Multinomial Theorem

    Horn, Martin Erik

    2003-01-01

    Part I: The two-dimensional Pascal Triangle will be generalized into a three-dimensional Pascal Pyramid and four-, five- or whatsoever-dimensional hyper-pyramids. Part II: The Bilateral Binomial Theorem will be generalised into a Bilateral Trinomial Theorem resp. a Bilateral Multinomial Theorem.

  12. Tiling a Pyramidal Polycube with Dominoes

    Olivier Bodini

    2007-05-01

    Full Text Available The notion of pyramidal polycubes, namely the piling-up of bricks of a non-increasing size, generalizes in ℝ n the concept of trapezoidal polyominoes. In the present paper, we prove that n-dimensional dominoes can tile a pyramidal polycube if and only if the latter is balanced, that is, if the number of white cubes is equal to the number of black ones for a chessboard-like coloration, generalizing the result of [BC92] when n=2

  13. Pyramidal central configurations and perverse solutions

    Zhifu Xie; Shiqing Zhang

    2004-01-01

    For $n$-body problems, a central configuration (CC) plays an important role. In this paper, we establish the relation between the spatial pyramidal central configuration (PCC) and the planar central configuration. We prove that the base of PCC is also a CC and we also prove that for some given conditions a planar CC can be extended to a PCC. In particular, if the pyramidal central configuration has a regular polygon base, then the masses of base are equal and the distance between the top vert...

  14. Multiresolution maximum intensity volume rendering by morphological adjunction pyramids

    Roerdink, Jos B.T.M.

    2003-01-01

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D eros

  15. A new class of morphological pyramids for multiresolution image analysis

    Roerdink, Jos B. T. M.; Asano, T.; Klette, R; Ronse, C.

    2003-01-01

    We study nonlinear multiresolution signal decomposition based on morphological pyramids. Motivated by a problem arising in multiresolution volume visualization, we introduce a new class of morphological pyramids. In this class the pyramidal synthesis operator always has the same form, i.e. a dilation by a structuring element A, preceded by upsampling, while the pyramidal analysis operator is a certain operator R(n)A indexed by an integer n, followed by downsampling. For n = 0, R(n)A equals th...

  16. Khufu, Khafre and Menkaure Pyramids and the Sun

    Sparavigna, Amelia Carolina

    2016-01-01

    In this paper we discuss the orientation of the Egyptian pyramids at Giza with respect to sunrises and sunsets, using SunCalc.net software. We can see that Khufu and Khafre pyramids had been positioned in a manner that, from each pyramid, it was always possible to observe the points of the horizon where the sun was rising and setting on each day of the year. A discussion for the Menkaure pyramid is also proposed.

  17. State ownership pyramid: extend and control

    Hanousek, Jan; Kočenda, Evžen

    Split : University of Split, Faculty of Economics, 2009, s. 1-25. [International Conference /8./ "Challenges of Europe: Financial Crisis and Climate Change". Split (HR), 21.05.2009-23.05.2009] Institutional research plan: CEZ:AV0Z70850503 Keywords : accounting efficiency * corporate pyramid * state control Subject RIV: AH - Economics

  18. Pyramid Project: An Exemplary Staff Development Plan.

    Ardmore City Schools, OK.

    The Ardmore, Oklahoma, School District developed the 3-year Pyramid Project to implement the following recommendations of the Sid W. Richardson Foundation Study of exemplary programs for high ability students: (1) broaden the process for assessing student abilities, (2) adopt continuous progress and appropriate pacing, (3) cultivate students'…

  19. Food Guide Pyramid Becomes a Plate

    ... español La pirámide nutricional se convierte en 'Mi plato' Plate = New Symbol for Healthy Eating Goodbye, pyramid. ... a friend Reprint Guidelines Sign up for our free weekly eNewsletters here About KidsHealth About Nemours Contact ...

  20. Ancient Pyramids Help Students Learn Math Concepts

    Smith, Courtney D.; Stump, Amanda M.; Lazaros, Edward J.

    2010-01-01

    This article presents an activity that allows students to use mathematics and critical-thinking skills to emulate processes used by the ancient Egyptians to prepare the site for the Pyramids of Giza. To accomplish this, they use three different methods. First, they create a square using only simple technological tools that were available to the…

  1. Teacher Acquisition of Functional Analysis Methods Using Pyramidal Training

    Pence, Sacha T.; St. Peter, Claire C.; Giles, Aimee F.

    2014-01-01

    Pyramidal training involves an experienced professional training a subset of individuals who, in turn, train additional individuals. Pyramidal training is effective for training a variety of behavior-analytic skills with direct-care staff, parents, and teachers. As teachers' roles in behavioral assessment increase, pyramidal training may be…

  2. On the astronomical orientation of the IV dynasty Egyptian pyramids and the dating of the second Giza pyramid

    Magli, Giulio

    2003-01-01

    The data on the astronomical orientation of the IV dynasty Egyptian pyramids are re-analyzed and it is shown that such data suggest an inverse chronology between the `first` and the `second` Giza pyramid.

  3. Pyramidal fractal dimension for high resolution images

    Mayrhofer-Reinhartshuber, Michael; Ahammer, Helmut

    2016-07-01

    Fractal analysis (FA) should be able to yield reliable and fast results for high-resolution digital images to be applicable in fields that require immediate outcomes. Triggered by an efficient implementation of FA for binary images, we present three new approaches for fractal dimension (D) estimation of images that utilize image pyramids, namely, the pyramid triangular prism, the pyramid gradient, and the pyramid differences method (PTPM, PGM, PDM). We evaluated the performance of the three new and five standard techniques when applied to images with sizes up to 8192 × 8192 pixels. By using artificial fractal images created by three different generator models as ground truth, we determined the scale ranges with minimum deviations between estimation and theory. All pyramidal methods (PM) resulted in reasonable D values for images of all generator models. Especially, for images with sizes ≥1024 ×1024 pixels, the PMs are superior to the investigated standard approaches in terms of accuracy and computation time. A measure for the possibility to differentiate images with different intrinsic D values did show not only that the PMs are well suited for all investigated image sizes, and preferable to standard methods especially for larger images, but also that results of standard D estimation techniques are strongly influenced by the image size. Fastest results were obtained with the PDM and PGM, followed by the PTPM. In terms of absolute D values best performing standard methods were magnitudes slower than the PMs. Concluding, the new PMs yield high quality results in short computation times and are therefore eligible methods for fast FA of high-resolution images.

  4. Hydrogen bonding to carbonyl oxygen of nitrogen-pyramidalized amide - detection of pyramidalization direction preference by vibrational circular dichroism spectroscopy.

    Wang, Siyuan; Taniguchi, Tohru; Monde, Kenji; Kawahata, Masatoshi; Yamaguchi, Kentaro; Otani, Yuko; Ohwada, Tomohiko

    2016-03-01

    Nitrogen-pyramidalization of amide increases electron density on nitrogen and decreases that on carbonyl oxygen. We identified hydrogen-bonding to carbonyl of nitrogen-pyramidalized bicyclic β-proline derivatives by crystallography, and by NMR and vibrational circular dichroism (VCD) spectroscopy in solution. Such hydrogen-bonding can switch the preferred nitrogen-pyramidalization direction, as detected by VCD spectroscopy. PMID:26889607

  5. How they (should have) built the pyramids

    West, J; Waters, K

    2014-01-01

    A novel method is proposed for moving large, pyramid construction size, stone blocks. The method is inspired by a well known introductory physics homework problem, and is implemented by tying 12 identical rods of appropriately chosen radius to the faces of the block. The rods form the corners and new faces that transform the square prism into a dodecagon which can then be moved more easily by rolling than by dragging. Experimental results are presented and compared to independent work by another group which utilized wooden attachments providing a cylindrical shape. It is found that a small scale stone block converted to dodecagons can be moved across level open ground with a dynamic coefficient of friction of the order 0.2. For full scale pyramid blocks, the wooden rods would need to be posts of order 30 cm in diameter, similar in size to those used as masts on ships in the Nile.

  6. Approximate Particle Spectra in the Pyramid Scheme

    Banks, Tom

    2012-01-01

    We construct a minimal model within the general class of Pyramid Schemes, which is consistent with both supersymmetry breaking and electroweak symmetry breaking. In order to do computations, we make unjustified approximations to the low energy K\\"ahler potential. The phenomenological viability of the resultant mass spectrum is then examined and compared with current collider limits. We show that, for certain regimes of parameters, the Pyramid Scheme can accommodate the current collider mass constraints on physics beyond the standard model with a tree-level light Higgs mass near 125 GeV. However, in this regime the model exhibits a little hierarchy problem, and one must permit fine-tunings that are generically 5%.

  7. Centre of pressure correlates with pyramid performance in acrobatic gymnastics.

    Floría, Pablo; Gómez-Landero, Luis Arturo; Harrison, Andrew J

    2015-01-01

    Acrobatic gymnasts need excellent balance control to execute pyramids where one gymnast is supported by another. The objectives of this study were: (1) to describe balance performance by assessing the centre of pressure displacement in a group of acrobatic gymnasts executing pyramids; (2) to determine the relationship between the parameters describing the centre of pressure oscillations and pyramid score; and (3) to examine the role of each foot in providing a solid base of support to maintain the balance of the pyramid. Sixteen acrobatic gymnasts grouped in pairs performed a Half pyramid and a Straddle pyramid held for 7 s on two force platforms. Path length, variance, range trajectory, and surface area of the centre of pressure of each foot were examined to analyse the balance of the pyramid. The path length was correlated with the pyramid score (Straddle: p = 0.692 [large]; Half: p = 0.407 [moderate]). There were differences in the functions of each leg to maintain balance, with the non-preferred leg supporting a higher weight of the pyramid while the preferred leg performed control movements to maintain balance. The results suggested that quantitative analysis of balance can provide important information on pyramid performance. PMID:26715236

  8. Design and fabrication of a pyramid wavefront sensor

    Wang, Aina; Yao, Jun; Cai, Dongmei; Ren, Hao

    2010-07-01

    A new pyramid wavefront sensor (PWFS), which utilizes a reflective pyramid mirror instead of a refractive pyramid prism at the focus of a telescope, is presented. As a key optical component in this PWFS, the pyramid mirror requires accurate microfabrication for excellent quality of the tip, the turned edges, and the surfaces. The moving mask lithography process is proposed for its economic, simple, and precise control to make the cross-sectional shape of the structure. The completed pyramid mirror has a square base of 1-mm length and four side facets inclined to the base at 3.7 deg. The sizes of the pyramid tip and turned edges are both about 6 μm, which show excellent aspects of sharpening-tip and knife-edges. The root mean square of four facets is approximately 70 nm, and the maximum profile deviation is 0.2 μm.

  9. Facial action detection using block-based pyramid appearance descriptors

    Jiang, Bihan; Valstar, Michel F.; Pantic, Maja

    2012-01-01

    Facial expression is one of the most important non-verbal behavioural cues in social signals. Constructing an effective face representation from images is an essential step for successful facial behaviour analysis. Most existing face descriptors operate on the same scale, and do not leverage coarse v.s. fine methods such as image pyramids. In this work, we propose the sparse appearance descriptors Block-based Pyramid Local Binary Pattern (B-PLBP) and Block-based Pyramid Local Phase Quantisati...

  10. General Mechanisms for Inverted Biomass Pyramids in Ecosystems

    Wang, Hao; Morrison, Wendy; Singh, Abhinav; Weiss, Howard

    2008-01-01

    Although the existence of robust inverted biomass pyramids seem paradoxical, they have been observed in planktonic communities, and more recently, in pristine coral reefs. Understanding the underlying mechanisms which produce inverted biomass pyramids provides new ecological insights, and for coral reefs, may help mitigate or restore damaged reefs. We present three classes of predator-prey models which elucidate mechanisms that generate robust inverted biomass pyramids. The first class of mod...

  11. Comparison of Morphological Pyramids for Multiresolution MIP Volume Rendering

    Roerdink, Jos B. T. M.

    2002-01-01

    We recently proposed a multiresolution representation for maximum intensity projection (MIP) volume rendering based on morphological adjunction pyramids which allow progressive refinement and have the property of perfect reconstruction. In this algorithm the pyramidal analysis and synthesis operators are composed of morphological erosion and dilation, combined with dyadic downsampling for analysis and dyadic upsampling for synthesis. Here we introduce an alternative pyramid scheme in which a ...

  12. A top-down construction scheme for irregular pyramids

    Goffe, Romain; Brun, Luc; Damiand, Guillaume

    2009-01-01

    Hierarchical data structures such as irregular pyramids are used by many applications related to image processing and segmentation. The construction scheme of such pyramids is bottom-up. Such a scheme forbids the definition of a level according to more global information defined at upper levels in the hierarchy. Moreover, the base of the pyramid has to encode any single pixel of the initial image in order to allow the definition of regions of any shape at higher levels. This last constraint r...

  13. Incidence of a pyramidal lobe on thyroid scans

    Gamma camera pertechnetate and radioiodine thyroid scans were reviewed to determine the incidence of recognition of a pyramidal lobe. Ten to 17% of normals and of patients with various thyroid disease states had a pyramidal lobe on their scans. However, in patients with diffuse toxic goiter, 43% had a pyramidal lobe on the thyroid images. There appears to be a correlation between elevated thyroid function studies (likely in thyroid mass) and the incidence of a pyramidal lobe on thyroid scans in diffuse toxic goiter

  14. Base-of-the-pyramid global strategy

    Boşcor, D.

    2010-12-01

    Full Text Available Global strategies for MNCs should focus on customers in emerging and developing markets instead of customers in developed economies. The “base-of-the-pyramid segment” comprises 4 billion people in the world. In order to be successful, companies will be required to form unconventional partnerships- with entities ranging from local governments to non-profit organizations - to gain the community’s trust and understand the environmental, infrastructure and political issues that may affect business. Being able to provide affordable, high-quality products and services in this market segment often means new approaches to marketing- new packaging and pricing structures, and using unfamiliar distribution structures.

  15. Cosmological SUSY Breaking and the Pyramid Schemes

    Banks, T

    2014-01-01

    I review the ideas of holographic space-time (HST), Cosmological SUSY breaking (CSB), and the Pyramid Schemes, which are the only known models of Tera-scale physics consistent with CSB, current particle data, and gauge coupling unification. There is considerable uncertainty in the estimate of the masses of supersymmetric partners of the standard model particles, but the model predicts that the gluino is probably out of reach of the LHC, squarks may be in reach, and the NLSP is a right handed slepton, which should be discovered soon.

  16. Dirac Gluinos in the Pyramid Scheme

    Banks, T

    2013-01-01

    I point out several terms in the low energy effective Lagrangian of the Pyramid Scheme, which were missed in a previous analysis of the phenomenological consequences of the model. They lead to a Dirac contribution to the gluino mass, much larger than the one loop Majorana mass. The gluino can thus be much heavier than in previous estimates, without introducing corresponding large loop corrections to squark masses. As pointed out by a number of authors, this ameliorates the tension between the predictions of the model, and LHC data. I also point out that the model has corrections to the Higgs potential, both at the tree and loop levels, which may ameliorate fine tuning.

  17. The Alphabet Pyramid of Team Development and Situation Leadership.

    Jarvis, Roy

    2001-01-01

    This pyramid model of team development has four sides--awareness, behavior, communication, and direction--on a foundation of evaluation. The four equal sides of a pyramid represent the equal importance of the different roles, including leader, within a team. All team members are involved in evaluation and deciding what is important, which empowers…

  18. Building Influenza Surveillance Pyramids in Near Real Time, Australia

    Dalton, Craig B; Carlson, Sandra J.; Butler, Michelle T; Elvidge, Elissa; Durrheim, David N

    2013-01-01

    A timely measure of circulating influenza virus severity has been elusive. Flutracking, the Australian online influenza-like illness surveillance system, was used to construct a surveillance pyramid in near real time for 2011/2012 participants and demonstrated a striking difference between years. Such pyramids will facilitate rapid estimation of attack rates and disease severity.

  19. nD generalized map pyramids: definition, representations and basic operations

    Grasset-Simon, Carine; Damiand, Guillaume; Lienhardt, Pascal

    2006-01-01

    Graph pyramids are often used for representing irregular image pyramids. For the 2D case, combinatorial pyramids have been recently defined in order to explicitly represent more topological information than graph pyramids. The main contribution of this work is the definition of pyramids of $n$-dimensional generalized maps. This extends the previous works to any dimension, and generalizes them in order to represent any type of pyramid built by using any removal and/or contraction operations. W...

  20. Location-dependent excitatory synaptic interactions in pyramidal neuron dendrites.

    Bardia F Behabadi

    Full Text Available Neocortical pyramidal neurons (PNs receive thousands of excitatory synaptic contacts on their basal dendrites. Some act as classical driver inputs while others are thought to modulate PN responses based on sensory or behavioral context, but the biophysical mechanisms that mediate classical-contextual interactions in these dendrites remain poorly understood. We hypothesized that if two excitatory pathways bias their synaptic projections towards proximal vs. distal ends of the basal branches, the very different local spike thresholds and attenuation factors for inputs near and far from the soma might provide the basis for a classical-contextual functional asymmetry. Supporting this possibility, we found both in compartmental models and electrophysiological recordings in brain slices that the responses of basal dendrites to spatially separated inputs are indeed strongly asymmetric. Distal excitation lowers the local spike threshold for more proximal inputs, while having little effect on peak responses at the soma. In contrast, proximal excitation lowers the threshold, but also substantially increases the gain of distally-driven responses. Our findings support the view that PN basal dendrites possess significant analog computing capabilities, and suggest that the diverse forms of nonlinear response modulation seen in the neocortex, including uni-modal, cross-modal, and attentional effects, could depend in part on pathway-specific biases in the spatial distribution of excitatory synaptic contacts onto PN basal dendritic arbors.

  1. The NGS Pyramid wavefront sensor for ERIS

    Riccardi, A.; Antichi, J.; Quirós-Pacheco, F.; Esposito, S.; Carbonaro, L.; Agapito, G.; Biliotti, V.; Briguglio, R.; Di Rico, G.; Dolci, M.; Ferruzzi, D.; Pinna, E.; Puglisi, A.; Xompero, M.; Marchetti, E.; Fedrigo, E.; Le Louarn, M.; Conzelmann, R.; Delabre, B.; Amico, P.; Hubin, N.

    2014-07-01

    ERIS is the new Single Conjugate Adaptive Optics (AO) instrument for VLT in construction at ESO with the collaboration of Max-Planck Institut fuer Extraterrestrische Physik, ETH-Institute for Astronomy and INAF - Osservatorio Astrofisico di Arcetri. The ERIS AO system relies on a 40×40 sub-aperture Pyramid Wavefront Sensor (PWFS) for two operating modes: a pure Natural Guide Star high-order sensing for high Strehl and contrast correction and a low-order visible sensing in support of the Laser Guide Star AO mode. In this paper we present in detail the preliminary design of the ERIS PWFS that is developed under the responsibility of INAF-Osservatorio Astrofisico di Arcetri in collaboration with ESO.

  2. Fabrication and measurement of a flexoelectric micro-pyramid composite

    Huang, Wenbin; Shu, Longlong; Ryung Kwon, Seol; Zhang, Shujun; Yuan, Fuh-Gwo; Jiang, Xiaoning

    2014-12-01

    A fabrication method by combining precision mechanical dicing and wet etching was developed to prepare micro-pyramid structures based on (Ba0.67Sr0.33)TiO3 ceramics. The effective piezoelectric properties of flexoelectric pyramid structures in ten micrometers scale were investigated and measured through converse flexoelectric effect. The scaling effect of the flexoelectric response was demonstrated as the structure size shrinks down. The results do suggest the great potential of flexoelectric micro pyramids as an alternative to lead-free piezoelectric material.

  3. NONLINEAR BENDING THEORY OF DIAGONAL SQUARE PYRAMID RETICULATED SHALLOW SHELLS

    肖潭; 刘人怀

    2001-01-01

    Double-deck reticulated shells are a main form of large space structures. One of the shells is the diagonal square pyramid reticulated shallow shell, whose its upper and lower faces bear most of the load but its core is comparatively flexible. According to its geometrical and mechanical characteristics, the diagonal square pyramid reticulated shallow shell is treated as a shallow sandwich shell on the basis of three basic assumptions. Its constitutive relations are analyzed from the point of view of energy and internal force equivalence. Basic equations of the geometrically nonlinear bending theory of the diagonal square pyramid reticulated shallow shell are established by means of the virtual work principle .

  4. Papillary Carcinoma Arising from the Pyramidal Lobe of the Thyroid

    The authors present a rare case of papillary carcinoma arising from the pyramidal lobe of the thyroid in a 54-year-old woman, who presented with a right submental palpable mass. An ultrasound evaluation depicted a 3 cm mixed echoic mass from the thyroid cartilage level without a focal lesion in the thyroid gland. Surgical specimens obtained during bilateral thyroidectomy confirmed papillary carcinoma of the pyramidal lobe. To the authors' knowledge, this is the first case report to describe papillary carcinoma arising from the pyramidal lobe of the thyroid gland

  5. PYRAMIDAL-HOLLOW-BEAM DIPOLE TRAP FOR ALKALI ATOMS

    YIN JIAN-PING; GAO WEI-JIAN; WANG YU-ZHU; ZHU YI-FU; WANG YI-QIU

    2000-01-01

    We propose a dark gravito-optical dipole trap, for alkali atoms, consisting of a blue-detuned, pyramidal-hollow laser beam propagating upward and the gravity field. When cold atoms from a magneto-optical trap are loaded into the pyramidal-hollow beam and bounce inside the pyramidal-hollow beam, they experience efficient Sisyphus cooling and geometric cooling induced by the pyramidal-hollow beam and the weak repumping beam propagating downward. Our study shows that an ultracold and dense atomic sample with an equilibrium 3D momentum of ~ 3hk and an atomic density above the point of Bose-Einstein condensation may be obtained in this pure optical trap.

  6. The Fishery of Truckee River and Pyramid Lake, Nevada

    US Fish and Wildlife Service, Department of the Interior — This report provides an overview of the Washoe Project Act. Trout populations in Pyramid Lake began to decline in the 1930s due to poor water quality and poor...

  7. The Personal Marketing Pyramid: A Model for Secretarial Success.

    Caudill, Donald W.

    1988-01-01

    The author describes his model of a synergistic approach to achieving success. His Personal Marketing Pyramid consists of four sciences: physiology, psychology, sociology, and philosophy. He uses examples related to success in a secretarial career. (CH)

  8. Fixing the Pole in the Pyramid

    Banks, Tom; Kathrein, Scott

    2009-01-01

    We revisit the problem of the hidden sector Landau pole in the Pyramid Scheme. There is a fixed line in the plane of hidden sector gauge coupling and a Yukawa coupling between the trianon fields. We postulate that the couplings flow to this line, at a point where the hidden sector gauge coupling is close to the strong coupling edge of its perturbative regime. Below the masses of the heavier trianons, the model quickly flows to a confining N_F=N_C=3 supersymmetric gauge theory, as required by phenomenological considerations. We study possible discrete R-symmetries, which guarantee, among other things, that the basin of attraction of the fixed line has full co-dimension in the space of R-allowed couplings. The Yukawa couplings required to get the fixed line violate the pyrma-baryon symmetries we invoked in previous work to find a dark matter candidate. Omitting one of them, we have a dark matter candidate, and an acceptable RG flow down from the unification scale, if the confinement scale of the hidden sector g...

  9. Activation of functional α7-containing nAChRs in hippocampal CA1 pyramidal neurons by physiological levels of choline in the presence of PNU-120596.

    Bopanna I Kalappa

    entire pyramidal neuron and occasionally trigger action potentials. CONCLUSIONS: 1 The majority of hippocampal CA1 pyramidal neurons express functional α7-containing nAChRs. In the absence of PNU-120596, a positive allosteric modulator of α7 nAChRs, a lack of responsiveness of some hippocampal CA1 pyramidal neurons to focal application of 0.5-1 mM choline does not imply a lack of expression of functional α7-containing nAChRs in these neurons. Rather, it may indicate a lack of detection of α7-containing nAChR-mediated currents by patch-clamp electrophysiology. 2 PNU-120596 can serve as a powerful tool for detection and enhancement of responsiveness of low densities of functional α7-containing nAChRs such as those present in hippocampal CA1 pyramidal neurons. 3 In the presence of PNU-120596, physiological concentrations of choline activate functional CA1 pyramidal α7-containing nAChRs and produce step-like currents that cause repetitive step-like depolarizations, occasionally triggering bursts of action potentials in CA1 pyramidal neurons. Therefore, the results of this study suggest that in the presence of PNU-120596 and possibly other positive allosteric modulators, endogenous choline may persistently activate CA1 pyramidal α7-containing nAChRs, enhance the excitability of CA1 pyramidal neurons and thus act as a potent therapeutic agent with potential neuroprotective and cognition-enhancing properties.

  10. Investigation of flow and pressure characteristics around pyramidal buildings

    Ikhwan, Muhammad

    2005-01-01

    Pyramidal buildings are undergoing a renaissance in todays architectural design due to their attractive mystery that has fascinated many architects. From an aerodynamic engineering point of view, structural buildings with the shape of a pyramid have their own interesting and particular aerodynamic characteristics as compared to other usual structural buildings (i.e. cuboidal). However, despite its distinct aerodynamic characteristics compared to other usual structural buildings, the flow a...

  11. Searching for Chambers and Caves in Teotihuacan's Sun Pyramid

    In this work a status report of a search for caves in the Sun pyramid in Teotihuacan, Mexico is presented. From an archeological perspective the main goal is to gather evidence to determine whether the pyramid was a state or a funerary temple. The general layout of the detector that is being built is an updated version of the one originally proposed by Alvarez et al.

  12. Pyramidal micro-mirrors for microsystems and atom chips

    Trupke, M; Curtis, E A; Ashmore, J P; Eriksson, S; Hinds, E A; Moktadir, Z; Gollasch, C; Kraft, M; Prakash, G V; Baumberg, J J

    2005-01-01

    Concave pyramids are created in the (100) surface of a silicon wafer by anisotropic etching in potassium hydroxide. High quality micro-mirrors are then formed by sputtering gold onto the smooth silicon (111) faces of the pyramids. These mirrors show great promise as high quality optical devices suitable for integration into MOEMS and atom chips. We have shown that structures of this shape can be used to laser-cool and hold atoms in a magneto-optical trap.

  13. Multiresolution maximum intensity volume rendering by morphological adjunction pyramids

    Roerdink, Jos B. T. M.

    2003-01-01

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D erosion and dilation, combined with dyadic downsampling for analysis and dyadic upsampling for synthesis. In this case the MIP operator can be interchanged with the synthesis operator. This fact is the...

  14. Mechanical Control of Graphene on Engineered Pyramidal Strain Arrays

    Gill, Stephen T.; Hinnefeld, John H.; Zhu, Shuze; Swanson, William T.; Li, Teng; Mason, Nadya

    2015-01-01

    Strain can tune desirable electronic behavior in graphene, but there has been limited progress in controlling strain in graphene devices. In this paper, we study the mechanical response of graphene on substrates patterned with arrays of mesoscale pyramids. Using atomic force microscopy, we demonstrate that the morphology of graphene can be controlled from conformal to suspended depending on the arrangement of pyramids and the aspect ratio of the array. Non-uniform strains in graphene suspende...

  15. Multiresolution Maximum Intensity Volume Rendering by Morphological Pyramids

    Roerdink, Jos B. T. M.; Ebert, D.; Favre, JM; Peikert, R.

    2001-01-01

    We propose a multiresolution representation for maximum intensity projection (MIP) volume rendering, based on morphological pyramids which allow progressive refinement and have the property of perfect reconstruction. The pyramidal analysis and synthesis operators are composed of morphological erosion and dilation, combined with dyadic downsampling for analysis and dyadic upsampling for synthesis. The structure of the multiresolution MIP representation is very similar to wavelet splatting, the...

  16. ASTRONOMICAL ALGORITHMS OF EGYPTIAN PYRAMIDS SLOPES AND THEIR MODULES DIVIDER

    Aboulfotouh, Hossam M. K.

    2015-01-01

    This paper is an attempt to show the astronomical design principles that are encoded in the geometrical forms of the largest five pyramids of the fourth Egyptian dynasty, in Giza and Dahshur plateaus, based on using the pyramids’ design-modules that are mentioned in the so-called Rhind Mathematical Papyrus. It shows the astronomical algorithms for quantifying the slopes of pyramids, with reference to specific range of earth’s axial tilt, within spherical co-ordinates system. Besid...

  17. Searching for Chambers and Caves in Teotihuacan's Sun Pyramid

    Alfaro, R.; Arrieta, E.; Barba P., L.; Becerril, A. D.; Belmont, E.; Carrillo, I.; Cabrera M., J. I.; Esquivel, O.; Grabski, V.; López R., J. M.; Manzanilla N., L.; Martínez D., A.; Menchaca R., A.; Moreno, M.; Núñez C., R.; Plascencia, J. C.; Rangel, M.; Villoro, M.

    2003-06-01

    In this work a status report of a search for caves in the Sun pyramid in Teotihuacan, México is presented. From an archeological perspective the main goal is to gather evidence to determine whether the pyramid was a state or a funerary temple. The general layout of the detector that is being built is an updated version of the one originally proposed by Alvarez et al..

  18. Controlled growth of hexagonal GaN pyramids by hot-wall MOCVD

    Lundskog, Anders; Hsu, Chih-Wei; Nilsson, Daniel; Karlsson, K. Fredrik; Forsberg, Urban; Holtz, Per-Olof; Janzén, Erik

    2013-01-01

    Hexagonal GaN pyramids have been fabricated by hot-wall metal organic chemical vapor deposition (hot-wall MOCVD) and the growth evolution have been studied. It was concluded that the pyramid growth can be divided into two regimes separated by the adsorption kinetics of the {1101} surfaces of the pyramids. In the adsorption regime, the pyramids grow simultaneously in the <1101> and [0001] -directions. In the zero-adsorption regime the pyramids grow only in the [0001] direction. Thus the ...

  19. Pyramid wavefront sensor for image quality evaluation of optical system

    Chen, Zhendong

    2015-08-01

    When the pyramid wavefront sensor is used to evaluate the imaging quality, placed at the focal plane of the aberrated optical system e.g., a telescope, it splits the light into four beams. Four images of the pupil are created on the detector and the detection signals of the pyramid wavefront sensor are calculated with these four intensity patterns, providing information on the derivatives of the aberrated wavefront. Based on the theory of the pyramid wavefront sensor, we are going to develop simulation software and a wavefront detector which can be used to test the imaging quality of the telescope. In our system, the subpupil image intensity through the pyramid sensor is calculated to obtain the aberration of wavefront where the piston, tilt, defocus, spherical, coma, astigmatism and other high level aberrations are separately represented by Zernike polynomials. The imaging quality of the optical system is then evaluated by the subsequent wavefront reconstruction. The performance of our system is to be checked by comparing with the measurements carried out using Puntino wavefront instrument (the method of SH wavefront sensor). Within this framework, the measurement precision of pyramid sensor will be discussed as well through detailed experiments. In general, this project would be very helpful both in our understanding of the principle of the wavefront reconstruction and its future technical applications. So far, we have produced the pyramid and established the laboratory setup of the image quality detecting system based on this wavefront sensor. Preliminary results are obtained, in that we have obtained the intensity images of the four pupils. Additional work is needed to analyze the characteristics of the pyramid wavefront sensor.

  20. Intraoperative tractography and neuronavigation of the pyramidal tract

    Diffusion tensor imaging (DTI) based fiber tracking was applied to visualize the course of the pyramidal tract in the surgical field by microscope-based navigation. In 70 patients with lesions adjacent to the pyramidal tract, DTI data were integrated in a navigational setup. Diffusion data (b=0) were rigidly registered with standard T1-weighted 3-D images. Fiber tracking was performed applying a tensor-deflection algorithm using a multiple volume of interest approach as seed regions for tracking. fMRI data identifying the motor gyrus were applied as selection criteria to define the fibers of interest. After tracking, a 3-D object was generated representing the pyramidal tract. In selected cases, the intraoperative image data (1.5 T intraoperative MRI) were used to update the navigation system. In all patients the pyramidal tract could be visualized in the operative field applying the heads-up display of the operating microscope. In 8 patients (11%) a new or aggravated postoperative paresis could be observed, which was transient in 5 of them; thus, only in 3 patients (4.2%) was there a new permanent neurological deficit. Intraoperative imaging depicted a shifting of the pyramidal tract which amounted up to 15 mm; even the direction of shifting was variable and could not be predicted before surgery, so that mathematical models trying to predict brain shift behaviour are of restricted value only. DTI fiber tracking data can be reliably integrated into navigational systems providing intraoperative visualization of the pyramidal tract. This technique allowed the resection of lesions adjacent to the pyramidal tract with low morbidity. (author)

  1. Pyramidal ice crystal scattering phase functions and concentric halos

    C. Liu

    Full Text Available Phase functions have been calculated using the Monte Carlo/geometric ray tracing method for single hexagonal pyramidal ice crystals (such as solid and hollow bullets randomly oriented in space and horizontal plane, in order to study the concentric halo formations. Results from three dimensional model calculations show that 9° halo can be as bright as the common 22° halo for pyramidal angle of 28°, and the 18°, 20°, 24° and 35° halos cannot be seen due to the strong 22° halo domination in the scattering phase function between 18° and 35°. For solid pyramidal ice crystals randomly oriented horizontally, the 35° arc can be produced and its intensity depends on the incident ray solar angle and the particle aspect ratio.

  2. A study of correlation technique on pyramid processed images

    M Sankar Kishore; K Veerabhadra Rao

    2000-02-01

    The pyramid algorithm is potentially a powerful tool for advanced television image processing and for pattern recognition. An attempt is made to design and develop both hardware and software for a system which performs decomposition and reconstruction of digitized images by implementing the Burt pyramid algorithm. In this work, an attempt is also made to study correlation performance on reconstructed images. That is, the reference image is taken from the original image and correlation is performed on expanded images of the same size. Similarly, correlation performance study is carried out on different pyramid- processed levels. In this paper results are presented in terms of RMS error between original and expanded images. Only still images are considered, and the hardware is designed around an i486 processor and software is developed in PL/M 86.

  3. Space Station view of the Pyramids at Giza

    2002-01-01

    One of the world's most famous archaeological sites has been photographed in amazing detail by the astronauts onboard Space Station Alpha. This image, taken 15 August, 2001, represents the greatest detail of the Giza plateau captured from a human-occupied spacecraft (approximate 7 m resolution). Afternoon sun casts shadows that help the eye make out the large pyramids of Khufu, Khafre and Menkaure. Sets of three smaller queens' pyramids can be seen to the east of the Pyramid of Khufu and south of the Pyramid of Menkaure. The light-colored causeway stretching from the Mortuary Temple at the Pyramid of Khafre to the Valley Temple near the Sphinx (arrow) can also be seen. Because it is not tall enough to cast a deep shadow, the Sphinx itself cannot readily be distinguished. Although some commercial satellites, such as IKONOS, have imaged the Pyramids at Giza in greater detail (1 m resolution), this image highlights the potential of the International Space Station as a remote sensing platform. A commercial digital camera without space modifications was used to obtain this picture. Similarly, a variety of remote sensing instruments developed for use on aircraft can potentially be used from the Space Station. Currently, all photographs of Earth taken by astronauts from the Space Shuttle and Space Station are released to the public for scientific and educational benefit and can be accessed on the World Wide Web through the NASA-JSC Gateway to Astronaut Photography of Earth (http://eol/jsc.nasa.gov/sseop). Image ISS003-ESC-5120 was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center (http://eol.jsc.nasa.gov).

  4. Indoor radon and thoron concentrations in the pyramides of Teotihuacan

    Radon and thoron concentrations measured in the prehispanic tunnel of the Sun Pyramid and in the archeological tunnel 1 in the Moon Pyramid are presented. Radon and thoron concentrations were measured using several electret passive environmental radon monitor (E-PERM) configurations and detection systems. Results were in good agreement with no significant difference (P E) calculated for the highest concentration was much lower than the action level (3-10 mSv x y-1). A quality assurance program was improved. (author)

  5. Geometry and perspective in the landscape of the Saqqara pyramids

    Magli, Giulio

    2009-01-01

    A series of peculiar, visual alignments between the pyramids of the pharaohs of the 4, 5 and 6 Egyptian dynasties exists. These alignments governed from the very beginning the planning of the funerary monuments of successive kings and, in some cases, led to establish building sites in quite inconvenient locations from the technical viewpoint. Explaining the topography of these monuments means therefore also investigating on their symbolic motivations: religion, power, dynastic lineage and social context, as well as getting insights on the skills of the ancient architects in astronomy and geometry. In the present paper we focus on the relationships between the Old Kingdom pyramids at Saqqara.

  6. Damage to the pyramidal tracts is necessary and sufficient for the production of the pyramidal syndrome in man.

    de Oliveira-Souza, Ricardo

    2015-07-01

    The causal role played by damage to the pyramidal tracts in the production of spastic hemiplegia in man has been hotly debated over the past hundred years. Two broad streams of thought have emerged from this dispute. The first, which is grounded on the clinicopathological schools of Jean-Martin Charcot (1825-1893) and Paul Flechsig (1847-1929), claimed that the four cardinal signs of hemiplegia, namely (i) paralysis, (ii) spasticity, (iii) hyperactive phasic muscle reflexes ("tendon jerks") and (iv) the sign of Babinski, are caused by injury or dysfunction of the pyramidal tracts. The second school, championed by John Farquhar Fulton (1899-1960) and Derek Denny-Brown (1901-1981), reflects the increasing influence of experimental neurology on clinicopathological concepts after World War II. According to this school, most elements of the pyramidal syndrome are caused by the added release or injury of extrapyramidal structures at different levels of the forebrain and brainstem. Most symptoms of spastic hemiplegia were thus interpreted as signs of extrapyramidal (e.g., reticulospinal) release or damage. However, consensus on which symptoms of spastic hemiplegia were due to pyramidal or extrapyramidal changes was never reached. To add to this uncertainty, a number of clinicopathological cases that supported the old view were sporadically published over the same period. The purpose of the present essay is to provide clinicoanatomic perspective to the neurological literature in support of the hypothesis that damage to the pyramidal tracts is a necessary and sufficient condition for the production of the complete pyramidal syndrome in man. PMID:25959865

  7. 76 FR 15358 - Culturally Significant Objects Imported for Exhibition Determinations: “Before the Pyramids: The...

    2011-03-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Before the Pyramids: The Origins of... ``Before the Pyramids: The Origins of Egyptian Civilization'' imported from abroad for temporary...

  8. Performance of resistance gene pyramids to races of rice bacterial blight in Zhejiang Province

    ZHENGKangle; ZHUANGJieyun; WANGHanrong

    1998-01-01

    The effect of gene pyramiding on resistance to bacterial blight (BB) in rice was evahlated among the IR24-based near isogenic lines conraining single resistance gene and gene pyramids containing two, three or lour resistancegenes (see table).

  9. A first step toward combinatorial pyramids in nD spaces

    Fourey, Sébastien; Brun, Luc

    2009-01-01

    Combinatorial maps define a general framework which allows to encode any subdivision of an nD orientable quasi-manifold with or without boundaries. Combinatorial pyramids are defined as stacks of successively reduced combinatorial maps. Such pyramids provide a rich framework which allows to encode fine properties of the objects (either shapes or partitions). Combinatorial pyramids have first been defined in 2D. This first work has latter been extended to pyramids of nD generalized combinatori...

  10. A first step toward combinatorial pyramids in n-D spaces

    Fourey, Sébastien; Brun, Luc

    2009-01-01

    Combinatorial maps define a general framework which allows to encode any subdivision of an n-D orientable quasi-manifold with or without boundaries. Combinatorial pyramids are defined as stacks of successively reduced combinatorial maps. Such pyramids provide a rich framework which allows to encode fine properties of the objects (either shapes or partitions). Combinatorial pyramids have first been defined in 2D. This first work has later been extended to pyramids of n-D generalized combinator...

  11. Connecting walks and connecting dart sequences for n-D combinatorial pyramids

    Fourey, Sébastien; Brun, Luc

    2009-01-01

    Combinatorial maps define a general framework which allows to encode any subdivision of an n-D orientable quasi-manifold with or without boundaries. Combinatorial pyramids are defined as stacks of successively reduced combinatorial maps. Such pyramids provide a rich framework which allows to encode fine properties of objects (either shapes or partitions). Combinatorial pyramids have first been defined in 2D. This first work has later been extended to pyramids of n-D generalized combinatorial ...

  12. Building trust at the Base of the Pyramid

    Grootveld, P.; Vermeulen, P.A.M.

    2014-01-01

    More and more companies are serving the poorest communities of our world, the so-called Base of the Pyramid (BoP). Wal-Mart, for example, moved into the Mexican retail-banking sector, claiming not only to “sell more stuff” but also to compete against the entrenched domestic businesses that are not f

  13. Was the Great Pyramid Built with Simple Machines?

    Kraft, Susan; Poynor, Leslie

    2004-01-01

    Recently one of the authors challenged her third-grade students to use their imagination and travel with her to Egypt. As they were exploring the Great Pyramid, she encouraged the students to speculate how ancient people could have built such a massive structure without the sophisticated machinery they have at our disposal today. This article…

  14. Using the Pyramid Approach to Teaching Marketing Research.

    Peltier, James W.; Westfall, John; Ainscough, Thomas L.

    2001-01-01

    Underscores the need for teaching marketing research skills at the secondary level and shows how marketing research fits into marketing education. Provides an example of how to use the pyramid approach to research, which involves review of secondary sources, key informant interviews, focus groups, and quantitative research. (Author/JOW)

  15. Radon measurements in the interior of the great pyramid

    Radon concentration measurements were made in the interior of the great pyramid of ''Cheops'' at Giza. Measurements were carried out using CR-39 as a solid state nuclear track detector. The CR-39 sheets were placed inside the Queen's and King's chambers and along the ascending corridor leading to them. An evaluation of the radon concentration is presented and discussed. (author)

  16. Ligand for neurotransmission SPECT in extra-pyramidal diseases

    It is now possible to study by scintigraphy some parameters of dopaminergic neurotransmission with iodinated ligands. Some clinical studies have shown the interest of this kind of exploration for the early diagnosis, the differential diagnosis and the follow-up of evolution and treatment of the different extra pyramidal pathologies. However, advances are still expected in several fields (tracers, cameras resolutions). (N.C.)

  17. The Sphinx and the Pyramids at Giza. Educational Packet.

    Gagliano, Sara; Rapport, Wendy

    This packet of materials was created to accompany the exhibit "The Sphinx and the Pyramids: 100 Years of American Archaeology at Giza" at the Semitic Museum of Harvard University. The lessons and teacher's guide focus on the following: (1) "The Mystery of the Secret Tomb" where students take on the role of an archaeologist by attempting to solve a…

  18. Organizing innovation in base-of-the-pyramid projects

    Boer, J. de; Steen, M.G.D.; Posthumus, A.L.

    2013-01-01

    Base-of-the-Pyramid (BoP) inclusive innovation projects aim to design, produce and market products and services for large and relatively poor market segments in developing countries, for example for people who have less than several dollars to spend per day. BoP projects have ‘normal’ goals, deliver

  19. The pyramid model as a structured way of quality management

    van der Tuuk Adriani Willem

    2008-01-01

    Full Text Available Three quality systems that can be used in blood establishments are briefly explained. The Pyramid model is described as a tool to manage the quality systems. Finally, some experiences in other countries are given to prove the validity of the system.

  20. Coxeter Decompositions of Bounded Hyperbolic Pyramids and Triangular Prisms

    Felikson, A.

    2002-01-01

    Coxeter decompositions of hyperbolic simplices where studied in math.MG/0212010 and math.MG/0210067. In this paper we use the methods of these works to classify Coxeter decompositions of bounded convex pyramids and triangular prisms in the hyperbolic space H^3.

  1. Increasing Accurate Preference Assessment Implementation through Pyramidal Training

    Pence, Sacha T.; St. Peter, Claire C.; Tetreault, Allison S.

    2012-01-01

    Preference assessments directly evaluate items that may serve as reinforcers, and their implementation is an important skill for individuals who work with children. This study examined the effectiveness of pyramidal training on teachers' implementation of preference assessments. During Experiment 1, 3 special education teachers taught 6 trainees…

  2. [Diagnostic significance of pathologic synkinesis for detection of pyramidal pathology].

    Baliasnyĭ, M M

    1991-01-01

    Five types of pathological synkinesis (++blepharo-ocular, ++blepharo-facial, ++bucco-manual, ++digito-digital on the hands, ++pedo-digital) are described. They are of definite importance for revealing pyramidal pathology including its early stages as well as for objective evaluation and observation of the time-course of changes in the illness. PMID:1654715

  3. Nanopore formation on Au coated pyramid under electron beam irradiations (plasmonic nanopore on pyramid

    Seong Soo Choi

    2016-03-01

    Full Text Available There have been tremendous interests about the single molecule analysis using a sold-state nanopore. The solid-state nanopore can be fabricated either by drilling technique, or diffusion technique by using electron beam irradiations. The solid-state SiN nanopore device with electrical detection technique recently fabricated, however, the solid-state Au nanopore with optical detection technique can be better utilized as the next generation single molecule sensor. In this report, the nanometer size openings with its size less than 10 nm on the diffused membrane on the 200 nm Au pyramid were fabricated by using field emission scanning electron microscopy (FESEM electron beam irradiations, transmission electron microscopy (TEM, etc. After the sample was being kept under a room environment for several months, several Au (111 clusters with ~6 nm diameter formed via Ostwald ripening are observed using a high resolution TEM imaging. The nanopore with Au nanoclusters on the diffused membrane can be utilized as an optical nanopore device.

  4. An algorithm for benchmarking an SIMD pyramid with the Abingdon Cross

    Teeuw, W.B.; Duin, R. P. W.

    1990-01-01

    Benchmarking an SIMD pyramid with the Abingdon Cross is discussed. Measured results for a simulated pyramid architecture on a CLIP4 processor array are presented, as well as estimates for a hypothetical hardware pyramid built with CLIP4 like processing elements.

  5. FBXO7 mutations cause autosomal recessive, early-onset parkinsonian-pyramidal syndrome.

    Fonzo, A. Di; Dekker, M.C.J.; Montagna, P.; Baruzzi, A.; Yonova, E.H.; Correia Guedes, L.; Szczerbinska, A.; Zhao, T.; Dubbel-Hulsman, L.O.; Wouters, C.H.; Graaff, E. de; Oyen, W.J.G.; Simons, E.J.; Breedveld, G.J.; Oostra, B.A.; Horstink, M.W.I.M.; Bonifati, V.

    2009-01-01

    BACKGROUND: The combination of early-onset, progressive parkinsonism with pyramidal tract signs has been known as pallido-pyramidal or parkinsonian-pyramidal syndrome since the first description by Davison in 1954. Very recently, a locus was mapped in a single family with an overlapping phenotype, a

  6. Presence of ESBL/AmpC-producing Escherichia coli in the broiler production pyramid: a descriptive study.

    Dierikx, C.M.; van der Goot, J. A.; Smith, H E; Kant, A.; Mevius, D.J.

    2013-01-01

    Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E. coli in the Dutch broiler produ...

  7. Experimental assessment of the pyramidal energy on water.

    Pedro Díaz Rebollido

    2006-04-01

    Full Text Available Background and objectives: The debate around the so called ¨pyramidal energy¨ among those that accept their multiple uses and those that reject them has been present both in the scientific community and the population. A recent research has suggested changes in the conductivity and the pH of the water, exposed to the pyramidal effect. The need to asses such a claim is the reason for the present study. Method: The study was developed in the laboratory of Physiology of the Faculty of Medical Sciences of Cienfuegos. We worked with 30 test tube numbered consecutively, stuffed with 500 ml of water. It was measured the electric conductivity and the pH of the wa-ter in each one of them. Later on, half of them, chosen at random, were placed during four hours under a pyramid, and the remaining ones were located outside of the pyramid. The electric conductivity and the pH were determined by means of the potenciometric method The pyramid employed was built with solid bars of aluminum, of skeletal structure; their dimensions were those established by specialists. It was placed so that two sides of its base were parallel to the North-South axis magnetic of the Earth. The measures were carried out in a blind way by one of the ours under the supervision of the other two co authors. Confidence intervals of the mean differences were computed under both experimental conditions and for the two considered variables. Complementarily, the stockings were compared by means of the Student t test. Results and Conclusions: The average (DS of the conductivity in the exposed test tubes to the pyramid before the exposition was 3,20 (0,07 and after 3,20 (0,05 (p=0,622; in the non exposed test tubes it was 3,18 (0,07 and 3,17 (0.06, (p=0.928. On the other hand, the average (DS values of the pH in the test tubes exposed to the pyramid before the exposition was 8,08 (0,78 and after 8.42 (0.13 (p=0.605, and in the non exposed test tubes 8,32 (0,89 and 8,44 (0,08, (p=0,127. The

  8. A study on radiation energy of Pyramidal shape 1- Effect of housing within a Pyramid model on cancer growth and some blood parameters of mice

    A study of solid tumor growth retardation by impaling the pyramid energy radiation in a pyramidal model shape was carried out. The great Pyramid of Egypt has evoked a keen interest since 1920, both for its architectural, marvel and mystical significance. Its strange thing (via shaping of razers, longer shelf life of vegetables, alerted states of consciousnesses, sleeping in hum and, wound healing). Power energy radiations are said to occur within a pyramid constructed in the exact geometric properties of Giza pyramid. The effect of housing in two different pyramidal shapes on cancer growth and some blood physiological indices in mice infected with cancer were observed. The results obtained that housing in pyramid shape cage significantly reduced the development of cancer, significant increase in liver enzymes activity and α feto proteins, however, no effect was observed in levels of thyroid hormones concentration when compared with their matched value in ordinary 2 inverted pyramid cages. It could be concluded that the radiation energy of pyramidal shapes might improve certain biochemical and physiological indices leading to tumor growth retardation

  9. Activation of Pyramidal Neurons in Mouse Medial Prefrontal Cortex Enhances Food-Seeking Behavior While Reducing Impulsivity in the Absence of an Effect on Food Intake

    Warthen, Daniel M.; Lambeth, Philip S.; Ottolini, Matteo; Shi, Yingtang; Barker, Bryan Scot; Gaykema, Ronald P.; Newmyer, Brandon A.; Joy-Gaba, Jonathan; Ohmura, Yu; Perez-Reyes, Edward; Güler, Ali D.; Patel, Manoj K.; Scott, Michael M

    2016-01-01

    The medial prefrontal cortex (mPFC) is involved in a wide range of executive cognitive functions, including reward evaluation, decision-making, memory extinction, mood, and task switching. Manipulation of the mPFC has been shown to alter food intake and food reward valuation, but whether exclusive stimulation of mPFC pyramidal neurons (PN), which form the principle output of the mPFC, is sufficient to mediate food rewarded instrumental behavior is unknown. We sought to determine the behaviora...

  10. Using Pyramids Effects as a method of nuclear and radiation protection

    Results most of experiments fixed that When radioactive waste is placed inside the pyramids, there is a decrease in their level of radioactivity Based on result of these experiments we suggest - Using Pyramids Effects as a method of nuclear and radiation protection. Explanation of this method based on 3 factors. (2 of them - internal factors, 1 of them - external factor) Factor I. Based o the Theory of the Pyramids Effects we know, that Pyramid construction separate the normal geomagnetic field of the Earth to 2 parts, which have difference vise verse physical characteristics. Cause of the energetic barrier of side of Pyramid, internal space of the Pyramid isolate from the influence of the external normal geomagnetic field of Earth. Therefore, internal space of the Pyramid is fulfilling only by the attractive power of the Earth (pic.1)

  11. Distributed GIS oriented generalized image pyramid and its practice

    2010-01-01

    Gaussian pyramid framework (GPF) and Laplacian pyramid framework (LPF) are the two main frameworks used for transmission and structure of spatial image and geometric data.LPF is the main approach for progressive transmission of spatial image data.This paper discusses the issues in structure,transmission and storage efficiency of spatial data in the current spatially distributed visualization system.Later in the paper a novel approach is introduced to structure and store spatial data based on the LPF.This new approach builds (spatial) index for transformed frequency data within different ranges based on splitting high-frequency and low-frequency data by biorthogonal transformation.This approach decreases the storage consumption and network data traffic for transmission while enables the progressive transmission of spatial image.

  12. New considerations on construction methods of the Ancient Egyptian pyramids

    Müller-Römer, Frank

    2011-01-01

    Many authors have attempted to account for the construction methods of the Old Kingdom pyramids, offering a broad scope of hypotheses concerning construction processes, building phases, mechanical devices, and workforce. Still, none of these suggestions have proved quite conclusive. All previous explanations involving ramps start from the assumption that building blocks were conveyed upwards on sledges pulled by bulls or workmen. However, in this case, sufficiently long ramps with a lesser sl...

  13. A Deep Pyramid Deformable Part Model for Face Detection

    Ranjan, Rajeev; Patel, Vishal M.; Chellappa, Rama

    2015-01-01

    We present a face detection algorithm based on Deformable Part Models and deep pyramidal features. The proposed method called DP2MFD is able to detect faces of various sizes and poses in unconstrained conditions. It reduces the gap in training and testing of DPM on deep features by adding a normalization layer to the deep convolutional neural network (CNN). Extensive experiments on four publicly available unconstrained face detection datasets show that our method is able to capture the meanin...

  14. A novel optical multilayer hydrophone with a triangular pyramid substrate

    Suyong Wu; Xingwu Long; Kaiyong Yang; Yun Huang

    2011-01-01

    @@ A novel concept for an optical multilayer ultrasonic hydrophone with the sensing film deposited on a triangular pyramid glass substrate is proposed. Using the calculation model for the spectral coefficients' derivatives of a dielectric multilayer optical coating, the acousto-optic sensitivity characteristic of the hydrophone is analyzed with different measurement laser polarizations and incident angles. We present a reasonable method and adjusting strategy for the optimum working point selection of the ultrasound measurement. Analytic results show that the novel hydrophone possesses all the other merits of a plate glass substrate optical multilayer hydrophone but with improved detection sensitivity. A longer measurement time without distortion decreases the difficulty of high frequency signal circuits. Spatial split of the ultrasound signal caused by the substrate's triangular pyramid roof simplifies the spatial spot area correction,which contributes to the accurate calibration of the hydrophone's wideband frequency response.%A novel concept for an optical multilayer ultrasonic hydrophone with the sensing film deposited on a triangular pyramid glass substrate is proposed. Using the calculation model for the spectral coefficients'derivatives of a dielectric multilayer optical coating, the acousto-optic sensitivity characteristic of the hydrophone is analyzed with different measurement laser polarizations and incident angles. We present a reasonable method and adjusting strategy for the optimum working point selection of the ultrasound measurement. Analytic results show that the novel hydrophone possesses all the other merits of a plate glass substrate optical multilayer hydrophone but with improved detection sensitivity. A longer measurement time without distortion decreases the difficulty of high frequency signal circuits. Spatial split of the ultrasound signal caused by the substrate's triangular pyramid roof simplifies the spatial spot area correction

  15. Induced Retirement, Social Security, and the Pyramid Mirage

    Casey B. Mulligan

    2000-01-01

    Does Social Security redistribute across cohorts? Or is it a program for purchasing the jobs' of the elderly? I formalize both models, showing how they have some predictions in common the most important of which is that generational accounts have the appearance of a pyramid scheme.' I also derive important differences between the two interpretations, and compare those differences with data on the design and incidence of Social Security programs around the world. Since implicit and explicit ta...

  16. Altered calcium metabolism in aging CA1 hippocampal pyramidal neurons

    Oh, M. Matthew; Oliveira, Fernando A.; Waters, Jack; Disterhoft, John F.

    2013-01-01

    Altered neuronal calcium homeostasis is widely hypothesized to underlie cognitive deficits in normal aging subjects, but the mechanisms that underlie this change are unknown, possibly due to a paucity of direct measurements from aging neurons. Using CCD and two-photon calcium imaging techniques on CA1 pyramidal neurons from young and aged rats, we show that calcium influx across the plasma membrane increases with aging, and that this change is countered by increased intracellular calcium buff...

  17. Genetic Stereo Matching Using Complex Conjugate Wavelet Pyramids

    L. Luo; Clewer, DR; Canagarajah, CN; Bull, DR

    2001-01-01

    A new genetic algorithm-based optimisation technique for stereo matching using complex conjugate wavelet pyramids is proposed. Reliable disparity fields are estimated in the wavelet domain with low computational cost. The new cost function is composed of the differences in wavelet coefficient values, plus vertical discontinuity and ordering constraints. Within homogenous regions, smoothness constraints on the disparity field are also employed. A genetic algorithm is used, where previously est...

  18. Geometry and perspective in the landscape of the Saqqara pyramids

    Magli, Giulio

    2009-01-01

    A series of peculiar, visual alignments between the pyramids of the pharaohs of the 4, 5 and 6 Egyptian dynasties exists. These alignments governed from the very beginning the planning of the funerary monuments of successive kings and, in some cases, led to establish building sites in quite inconvenient locations from the technical viewpoint. Explaining the topography of these monuments means therefore also investigating on their symbolic motivations: religion, power, dynastic lineage and soc...

  19. Invariant representative cocycles of cohomology generators using irregular graph pyramids

    González Díaz, Rocío; Ion, Adrián; Iglesias Ham, Mabel; Kropatsch, Walter G.

    2011-01-01

    Structural pattern recognition describes and classifies data based on the relationships of features and parts. Topological invariants, like the Euler number, characterize the structure of objects of any dimension. Cohomology can provide more refined algebraic invariants to a topological space than does homology. It assigns `quantities' to the chains used in homology to characterize holes of any dimension. Graph pyramids can be used to describe subdivisions of the same object at multiple level...

  20. Combinatorial pyramids and discrete geometry for energy-minimizing segmentation

    Braure De Calignon, Martin; Brun, Luc; Lachaud, Jacques-Olivier

    2009-01-01

    This paper defines the basis of a new hierarchical framework for segmentation algorithms based on energy minimization schemes. This new framework is based on two formal tools. First, a combinatorial pyramid encode efficiently a hierarchy of partitions. Secondly, discrete geometric estimators measure precisely some important geometric parameters of the regions. These measures combined with photometrical and topological features of the partition allows to design energy terms based on discrete m...

  1. Signal Propagation in Oblique Dendrites of CA1 Pyramidal Cells

    Migliore, Michele; Ferrante, Michele; Ascoli, Giorgio A.

    2005-01-01

    The electrophysiological properties of the oblique branches of CA1 pyramidal neurons are largely unknown and very difficult to investigate experimentally. These relatively thin dendrites make up the majority of the apical tree surface area and constitute the main target of Schaffer collateral axons from CA3. Their electrogenic properties might have an important role in defining the computational functions of CA1 neurons. It is thus important to determine if and to what extent the back- and fo...

  2. Image content authentication technique based on Laplacian Pyramid

    2008-01-01

    This paper proposes a technique of image content authentication based on the Laplacian Pyramid to verify the authenticity of image content.First,the image is decomposed into Laplacian Pyramid before the transformation.Next,the smooth and detail properties of the original image are analyzed according to the Laplacian Pyramid,and the properties are classified and encoded to get the corresponding characteristic values.Then,the signature derived from the encrypted characteristic values is embedded in the original image as a watermark.After the reception,the characteristic values of the received image are compared with the watermark drawn out from the image.The algorithm automatically identifies whether the content is tampered by means of morphologic filtration.The information of tampered location is Presented at the same time.Experimental results show that the pro posed authentication algorithm can effectively detect the event and location when the original image content is tampered.Moreover,it can tolerate some distortions produced by compression,filtration and noise degradation.

  3. Amending Miller's Pyramid to Include Professional Identity Formation.

    Cruess, Richard L; Cruess, Sylvia R; Steinert, Yvonne

    2016-02-01

    In 1990, George Miller published an article entitled "The Assessment of Clinical Skills/Competence/Performance" that had an immediate and lasting impact on medical education. In his classic article, he stated that no single method of assessment could encompass the intricacies and complexities of medical practice. To provide a structured approach to the assessment of medical competence, he proposed a pyramidal structure with four levels, each of which required specific methods of assessment. As is well known, the layers are "Knows," "Knows How," "Shows How," and "Does." Miller's pyramid has guided assessment since its introduction; it has also been used to assist in the assessment of professionalism.The recent emphasis on professional identity formation has raised questions about the appropriateness of "Does" as the highest level of aspiration. It is believed that a more reliable indicator of professional behavior is the incorporation of the values and attitudes of the professional into the identity of the aspiring physician. It is therefore proposed that a fifth level be added at the apex of the pyramid. This level, reflecting the presence of a professional identity, should be "Is," and methods of assessing progress toward a professional identity and the nature of the identity in formation should be guided by currently available methods. PMID:26332429

  4. The pyramid wavefront sensor for the high order testbench (HOT)

    Pinna, E.; Puglisi, A. T.; Quiros-Pacheco, F.; Busoni, L.; Tozzi, A.; Esposito, S.; Aller-Carpentier, E.; Kasper, M.

    2008-07-01

    The High Order Testbench (HOT) is a joint experiment of ESO, Durham University and Arcetri Observatory to built and test in laboratory the performance of Shack-Hartmann and pyramid sensor in a high-order correction loop using a 32x32 actuators MEMS DM. This paper will describe the pyramid wavefront sensor unit developed in Arcetri and now installed in the HOT bench at ESO premises. In the first part of this paper we will describe the pyramid wavefront sensor opto-mechanics and its real-time computer realized with a commercial Linux-PC. In the second part we will show the sensor integration and alignment in the HOT bench and the experimental results obtained at ESO labs. Particular attention will be paid to the implementation of the modal control strategy, like modal basis definition, orthogonalization on the real pupil, and control of edge actuators. A stable closed loop controlling up to 667 modes has been achieved obtaining a Strehl ratio of 90 -- 93% in H band.

  5. Endocannabinoids differentially modulate synaptic plasticity in rat hippocampal CA1 pyramidal neurons.

    Jian-Yi Xu

    Full Text Available BACKGROUND: Hippocampal CA1 pyramidal neurons receive two excitatory glutamatergic synaptic inputs: their most distal dendritic regions in the stratum lacunosum-moleculare (SLM are innervated by the perforant path (PP, originating from layer III of the entorhinal cortex, while their more proximal regions of the apical dendrites in the stratum radiatum (SR are innervated by the Schaffer-collaterals (SC, originating from hippocampal CA3 neurons. Endocannabinoids (eCBs are naturally occurring mediators capable of modulating both GABAergic and glutamatergic synaptic transmission and plasticity via the CB1 receptor. Previous work on eCB modulation of excitatory synapses in the CA1 region largely focuses on the SC pathway. However, little information is available on whether and how eCBs modulate glutamatergic synaptic transmission and plasticity at PP synapses. METHODOLOGY/PRINCIPAL FINDINGS: By employing somatic and dendritic patch-clamp recordings, Ca(2+ uncaging, and immunostaining, we demonstrate that there are significant differences in low-frequency stimulation (LFS- or DHPG-, an agonist of group I metabotropic glutamate receptors (mGluRs, induced long-term depression (LTD of excitatory synaptic transmission between SC and PP synapses in the same pyramidal neurons. These differences are eliminated by pharmacological inhibition with selective CB1 receptor antagonists or genetic deletion of the CB1 receptor, indicating that these differences likely result from differential modulation via a CB1 receptor-dependent mechanism. We also revealed that depolarization-induced suppression of excitation (DSE, a form of short-term synaptic plasticity, and photolysis of caged Ca(2+-induced suppression of Excitatory postsynaptic currents (EPSCs were less at the PP than that at the SC. In addition, application of WIN55212 (WIN induced a more pronounced inhibition of EPSCs at the SC when compared to that at the PP. CONCLUSIONS/SIGNIFICANCE: Our results suggest

  6. Changes in the axonal conduction velocity of pyramidal tract neurons in the aged cat.

    Xi, M C; Liu, R H; Engelhardt, J K; Morales, F R; Chase, M H

    1999-01-01

    The present study was undertaken to determine whether age-dependent changes in axonal conduction velocity occur in pyramidal tract neurons. A total of 260 and 254 pyramidal tract neurons were recorded extracellularly in the motor cortex of adult control and aged cats, respectively. These cells were activated antidromically by electrical stimulation of the medullary pyramidal tract. Fast- and slow-conducting neurons were identified according to their axonal conduction velocity in both control and aged cats. While 51% of pyramidal tract neurons recorded in the control cats were fast conducting (conduction velocity greater than 20 m/s), only 26% of pyramidal tract neurons in the aged cats were fast conducting. There was a 43% decrease in the median conduction velocity for the entire population of pyramidal tract neurons in aged cats when compared with that of pyramidal tract neurons in the control cats (P cats. However, the regression slope was significantly reduced in aged cats. This reduction was due to the appearance of a group of pyramidal tract neurons with relatively shorter spike durations but slower axonal conduction velocities in the aged cat. Sample intracellular data confirmed the above results. These observations form the basis for the following conclusions: (i) there is a decrease in median conduction velocity of pyramidal tract neurons in aged cats; (ii) the reduction in the axonal conduction velocity of pyramidal tract neurons in aged cats is due, in part, to fibers that previously belonged to the fast-conducting group and now conduct at slower velocity. PMID:10392844

  7. Co-precipitation of dissolved organic matter by calcium carbonate in Pyramid Lake, Nevada

    Leenheer, Jerry A.; Reddy, Michael M.

    2008-01-01

    Our previous research has demonstrated that dissolved organic matter (DOM) influences calcium carbonate mineral formation in surface and ground water. To better understand DOM mediation of carbonate precipitation and DOM co-precipitation and/or incorporation with carbonate minerals, we characterized the content and speciation of DOM in carbonate minerals and in the lake water of Pyramid Lake, Nevada, USA. A 400-gram block of precipitated calcium carbonate from the Pyramid Lake shore was dissolved in 8 liters of 10% acetic acid. Particulate matter not dissolved by acetic acid was removed by centrifugation. DOM from the carbonate rock was fractionated into nine portions using evaporation, dialysis, resin adsorption, and selective precipitations to remove acetic acid and inorganic constituents. The calcium carbonate rock contained 0.23% DOM by weight. This DOM was enriched in polycarboxylic proteinaceous acids and hydroxy-acids in comparison with the present lake water. DOM in lake water was composed of aliphatic, alicyclic polycarboxylic acids. These compound classes were found in previous studies to inhibit calcium carbonate precipitation. DOM fractions from the carbonate rock were 14C-age dated at about 3,100 to 3,500 years before present. The mechanism of DOM co-precipitation and/or physical incorporation in the calcium carbonate is believed to be due to formation of insoluble calcium complexes with polycarboxylic proteinaceous acids and hydroxy-acids that have moderately large stability constants at the alkaline pH of the lake. DOM co-precipitation with calcium carbonate and incorporation in precipitated carbonate minerals removes proteinaceous DOM, but nearly equivalent concentrations of neutral and acidic forms of organic nitrogen in DOM remain in solution. Calcium carbonate precipitation during lime softening pretreatment of drinking water may have practical applications for removal of proteinaceous disinfection by-product precursors.

  8. Technique Based on Image Pyramid and Bayes Rule for Noise Reduction in Unsupervised Change Detection

    LI Zhi-qiang; HUO hong; FANG Tao; ZHU Ju-lian; GE Wei-li

    2009-01-01

    In this paper, a technique based on image pyramid and Bayes rule for reducing noise effects in unsupervised change detection is proposed. By using Gaussian pyramid to process two multitemporal images respectively, two image pyramids are constructed. The difference pyramid images are obtained by point-by-point subtraction between the same level images of the two image pyramids. By resizing all difference pyramid images to the size of the original multitemporal image and then making product operator among them, a map being similar to the difference image is obtained. The difference image is generated by point-by-point subtraction between the two multitemporal images directly. At last, the Bayes rule is used to distinguish the changed pixels. Both synthetic and real data sets are used to evaluate the performance of the proposed technique. Experimental results show that the map from the proposed technique is more robust to noise than the difference image.

  9. Pyramidal Neurons Switch From Integrators In Vitro to Resonators Under In Vivo-Like Conditions

    Prescott, Steven A.; Ratté, Stéphanie; De Koninck, Yves; Sejnowski, Terrence J.

    2008-01-01

    During wakefulness, pyramidal neurons in the intact brain are bombarded by synaptic input that causes tonic depolarization, increased membrane conductance (i.e., shunting), and noisy fluctuations in membrane potential; by comparison, pyramidal neurons in acute slices typically experience little background input. Such differences in operating conditions can compromise extrapolation of in vitro data to explain neuronal operation in vivo. For instance, pyramidal neurons have been identified as i...

  10. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas

    Concha Bielza; Ruth Benavides-Piccione; Pedro López-Cruz; Pedro Larrañaga; Javier DeFelipe

    2014-01-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven differen...

  11. Formation of the Pyramid Lake Paiute Tribal Council, 1934-1936

    Rusco, Elmer R.

    1988-01-01

    The Pyramid Lake Paiute Tribe is today recognized by the federal government as a semi-sovereign society within the American polity. Its government, the Pyramid Lake Paiute Tribal Council, is acknowledged to be the governing body of the tribe and to have jurisdiction over the Pyramid Lake Reservation in northwestern Nevada, except where that jurisdiction has been eliminated or weakened by explicit action of the Congress of the United States (Cohen 1982). Before the 1930s, however, although the...

  12. Determinants of Firm Affiliation to Pyramid Structure: A Survey from Malaysian Public Listed Firms

    Irfah Najihah Basir Malan; Norhana Salamudin; Noryati Ahmad

    2013-01-01

    This research seeks to examine the determinants of affiliation to pyramid structure of Malaysian public listed firms. A motivation of the research comes from the phenomenon of pyramid structure causing divergence of ultimate owners’ actual ownership and control leading to severe expropriation of minority shareholders’ interest. The method adapts Attig Model and employs Panel Generalised Least Square on 136 Malaysian pyramid firms over a twenty one-year period from 1990 to 2010. There are ten ...

  13. Higher-Order Finite Elements for Hybrid Meshes Using New Nodal Pyramidal Elements

    Bergot, Morgane; Cohen, Gary; Duruflé, Marc

    2010-01-01

    We provide a comprehensive study of arbitrarily high-order finite elements defined on pyramids. We propose a new family of high-order nodal pyramidal finite element which can be used in hybrid meshes which include hexahedra, tetrahedra, wedges and pyramids. Finite elements matrices can be evaluated through approximate integration, and we show that the order of convergence of the method is conserved. Numerical results demonstrate the efficiency of hybrid meshes compared to pure tetrahedral mes...

  14. Removal and contraction operations to define combinatorial pyramids: application to the design of a spatial modeler

    Damiand, Guillaume; Dexet, Martine; Lienhardt, Pascal; Andres, Eric

    2005-01-01

    Removal and contraction are basic operations for several methods conceived in order to handle irregular image pyramids, for multi-level image analysis for instance. We give the definitions of removal and contraction operations in the generalized maps framework. We propose a first experimentation of irregular pyramid as a basis for a discrete geometrical modeler that can handle both discrete and continuous representations of geometrical objects. This modeler is based on a pyramidal kernel with...

  15. Pyramidal and Chiral Groupings of Gold Nanocrystals Assembled Using DNA Scaffolds

    Mastroianni, Alexander

    2009-01-01

    Nanostructures constructed from metal and semiconductor nanocrystals conjugated to, and organized by DNA are an emerging class of material with collective optical properties. We created discrete pyramids of DNA with gold nanocrystals at the tips. By taking small angle X-ray scattering (SAXS) measurments from solutions of these pyramids we confirmed that this pyramidal geometry creates structures which are more rigid in solution than linear DNA. We then took advantage of the tetrahedral sym...

  16. Fabrication of micro-mirrors with pyramidal shape using anisotropic etching of silicon

    Moktadir, Z; Koukharenko, E; Kraft, M; Prakash, G V; Baumberg, J J; Trupke, M; Eriksson, S; Hinds, E A

    2004-01-01

    Gold micro-mirrors have been formed in silicon in an inverted pyramidal shape. The pyramidal structures are created in the (100) surface of a silicon wafer by anisotropic etching in potassium hydroxide. High quality micro-mirrors are then formed by sputtering gold onto the smooth silicon (111) faces of the pyramids. These mirrors show great promise as high quality optical devices suitable for integration into MOEMS systems.

  17. Nanoreplicated positive and inverted sub-micron polymer pyramids array for surface enhanced Raman spectroscopy (SERS)

    Xu, Zhida; Liu, Logan

    2014-01-01

    We demonstrate gold coated polymer surface enhanced Raman scattering (SERS) substrates with a pair of complementary structures--positive and inverted pyramids array structures fabricated by multiple-step molding and replication process. The uniform SERS enhancement factors over the entire device surfaces were measured as 7.2 X 10^4 for positive pyramids substrate while 1.6 X 10^6 for inverted pyramids substrate with Rhodamine 6G as the target analyte. Based on the optical reflection measureme...

  18. On the problem of the stability of pyramidal structures on bombarded copper surfaces

    The morphological evolution of pyramids, developed on bombarded copper surfaces, as a function of consecutive doses of 12 keV Kr+ ions from 2.4 x 1016 up to 3 x 1019 ions/cm2, has been studied. In disagreement with many previous studies, apparently based on a limited choice of doses which were sometimes not in sequence, it was found that the pyramids disappeared at high enough doses. Pyramids are therefore not an equilibrium structure. (author)

  19. Pyramidal and Chiral Groupings of Gold Nanocrystals Assembled Using DNA Scaffolds

    Mastroianni, Alexander; Claridge, Shelley; Alivisatos, A. Paul

    2009-01-01

    Nanostructures constructed from metal and semiconductor nanocrystals conjugated to, and organized by DNA are an emerging class of material with collective optical properties. We created discrete pyramids of DNA with gold nanocrystals at the tips. By taking small angle X-ray scattering (SAXS) measurments from solutions of these pyramids we confirmed that this pyramidal geometry creates structures which are more rigid in solution than linear DNA. We then took advantage of the tetrahedral symmet...

  20. Astronomical Orientation of Pyramid Tombs in North China

    Rusell Tiede, Vance

    2010-01-01

    Two ancient Chinese texts, the Chou Bei Suan Ching and Chou Li (Western Han Dynasty, ca. 100 BC), record that the Imperial Astronomer (Feng Hsian Shin) made solar observations to determine the solstices and equinoxes, and for determining the cardinal directions with a circle and gnomon. By combining the techniques of astro-archaeology (G. S. Hawkins, 1968) with both overhead imagery and ground survey, the present study seeks to link historical Chinese descriptions of astronomical phenomena with contemporary architectural orientation. In the process, several unexpected astronomical orientation patterns emerged which apparently do not appear in the surviving historical record. For example, at the imperial Western Han capital of Ch'ang-an (N 34° latitude), the diagonals of cardinally oriented square pyramid mounds (ling) align to zenith (+34° declination) and nadir (-34° declination) star rise and set points on the skyline. This is in accord with the Chou (Zhou) Dynasty's name of Chung-Kuo, meaning Central Country or Middle Kingdom. That is, the imperial capital is centered both politico-geographically with respect to its vassal states of the Eastern Yi, Southern Man, Western Rong, and Northern Di, as well as astro-geomantically regarding the color-coded Five Sacred Directions East-South-West-North-Zenith/Nadir in the Cosmos. Our ground survey also confirmed pyramid orientation to the lunar standstills (+28°, +18° and +5° declination) that we reported from overhead imagery in 1980 (155th AAS Meeting, HAD 18.CE.12, Lunar and Solar Alignments of Ancient Chinese Pyramids). Grateful acknowledgment is given to the Chinese Academy of Sciences for the invitation to conduct an astro-archaeological survey of the Wei-ho valley, Shensi (Shaanxi) Province.

  1. Using cosmic muons to search for cavities in the Pyramid of the Sun, Teotihuacan: preliminary results

    Over the last two years the Pyramid of the Sun, at Teotihuacan, Mexico, has been searched for possible hidden chambers by means of muon attenuation measurements inside the monument’s volume. The experimental method is based on the use of a muon tracker placed in a chamber at the end of a tunnel, which runs below the base, and ends close to the symmetry axis of the pyramid. The accumulated experimental data, when compared to physics simulations using GEANT4, already show identifiable known features of the external shape of the pyramid. Experimental results of the relative density distribution inside the pyramid are presented and compared to the aforementioned Monte Carlo simulations

  2. Rezension zu: Emily Teeter (Hg.), Before the pyramids. The origins of Egyptian civilization

    Köpp-Junk, Heidi

    2013-01-01

    Rezension zu: Emily Teeter (Hg.), Before the Pyramids. The Origins of Egyptian Civilization. The Oriental Institute of the University of Chicago, Oriental Institute Museum Publications 33 (Chicago 2011)

  3. Enumeration of pyramids of one-dimensional pieces of arbitrary fixed integer length

    Durhuus, Bergfinnur; Eilers, Søren

    2009-01-01

    We consider pyramids made of one-dimensional pieces of fixed integer length a and which may have pairwise overlaps of integer length from 1 to a. We prove that the number of pyramids of size m, i.e. consisting of m pieces, equals (am-1,m-1) for each a >= 2. This generalises a well known result for a = 2. A bijective correspondence between so-called right (or left) pyramids and a-ary trees is pointed out, and it is shown that asymptotically the average width of pyramids is proportional to t...

  4. Combinatorial aspects of pyramids of one-dimensional pieces of fixed integer length

    Durhuus, Bergfinnur; Eilers, Søren

    2010-01-01

    We consider pyramids made of one-dimensional pieces of fixed integer length a and which may have pairwise overlaps of integer length from 1 to a. We give a combinatorial proof that the number of pyramids of size m, i.e., consisting of m pieces, equals am-1\\choose m-1 for each a≥2. This generalises a well known result for a=2. A bijective correspondence between so-called right (or left) pyramids and a-ary trees is pointed out, and it is shown that asymptotically the average width of pyramids e...

  5. The production of regular pyramids on argon ion bombarded surfaces of copper crystals

    Argon ion bombardment of poly-crystalline copper is shown to produce pyramid covered surfaces on grains having orientation in particular high index direction. Single crystals cut in similar direction also show pyramid covered surfaces when bombarded with 40 keV argon ions. Evidence is presented to show that the dominant parameter contributing to pyramid production is crystallographic, rather than impurity-induced as proposed in earlier works. The pyramids are of such regular size, shape and spacing that light is selectively absorbed and for 40 keV argon ion bombardment, only light of red colour is reflected from an initially plane surface. (Auth.)

  6. Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

    We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

  7. Dynamics of multi-tethered pyramidal satellite formation

    Alary, D.; Andreev, K.; Boyko, P.; Ivanova, E.; Pritykin, D.; Sidorenko, V.; Tourneur, C.; Yarotsky, D.

    2015-12-01

    This paper is devoted to the dynamics of a multi-tethered pyramidal satellite formation rotating about its axis of symmetry in the nominal mode. Whereas the combination of rotation and gravity-gradient forces is insufficient to maintain the mutual positions of satellites, they are assumed to be equipped with low-thrust rocket engines. We propose a control strategy that allows the stabilization of the nominal spin state and demonstrate the system's proper operation by numerically simulating its controlled motion. The discussed multi-tethered formations could be employed, for example, to provide co-location of several satellites at a slot in geostationary orbit.

  8. Your Guide to Healthy Eating Using the Food Pyramid

    Department of Health

    2012-01-01

    Do you want to feel good and have more energy? Do you want to maintain a healthy weight and help reduce your risk of becoming ill from high blood pressure, high cholesterol, heart disease, type 2 diabetes, cancer and other chronic diseases?Eating healthy food and being physically active are two of the most importantsteps that you can take to improve your health. To help you do this, follow the Healthy Eating Guidelines, use the Food Pyramid Guide and the Physical Activity Guidelines. Cl...

  9. Value Chain and Innovation at the Base of the Pyramid

    Esko, Siim; Zeromskis, Mindaugas; Hsuan, Juliana

    2013-01-01

    introduced for analysing business readiness in BoP: organisation, value chain and strategy. Four diverse cases were analysed: GE’s reverse innovation project, GrameenPhone, Essilor, and P&G’s PuR. Findings – BoP project should be a top-down supported separate entity with its own strategic processes and......Purpose – This paper aims to investigate the factors a multinational corporation should adapt when doing business at the bottom of the pyramid (BoP) markets. Design/methodology/approach – Based on a systematic literature review on BoP, value chain and innovation, an integrative framework is...

  10. Morphological evolution of GaN nano-pyramids grown by using metal-organic chemical vapor deposition

    High-density GaN nano-pyramids were grown on a nano-sized SiO2 pattern, and their morphological evolution was characterized. The effect of the growth temperature was studied with respect to pyramidal growth and was analyzed based on the growth rate anisotropy among crystal planes. At 750 .deg. C, uniform nano-pyramids surrounded by (1101) facets were easily formed due to the large growth rate anisotropy of the planes while the pyramids showed smooth surfaces at 950 .deg. C. We observed that a low growth temperature was beneficial in suppressing the growths of giant pyramids formed by the coalescence of several smaller pyramids.

  11. Indentation size effect in spherical and pyramidal indentations

    The indentation size effect (ISE) is studied for spherical and pyramidal indentations on a Ni poly-crystal. The indentation experiments were conducted using a Berkovich geometry as well as different spherical indenters with radii of 0.38, 3.8 and 51.0 μm. A strong ISE is observed for the material yielding a higher hardness at smaller depths or smaller sphere radii. The transition from elastic to plastic behaviour is associated with a pop-in in the load-displacement curve, in contrast to the conventional elastic-plastic transition as discussed by Tabor. The indentation response is modelled using Tabor's approach in conjunction with the uniaxial macroscopic stress-strain behaviour for calculating the statistically stored dislocation density for a given indenter geometry. The geometrically necessary dislocation (GND) density is calculated using a modified Nix/Gao approach, whereas the storage volume for GNDs is used as a parameter for the measured depth dependence of hardness. It will be shown that the ISE for both pyramidal and spherical indentations is related and can be understood within the same given framework. The indentation response of metallic materials can thus be modelled from pop-in to macroscopic hardness

  12. Path-search in the pyramid and in other graphs

    Gerbner, Dániel

    2011-01-01

    We are given an acyclic directed graph with one source, and a subset of its edges which contains exactly one outgoing edge for every non-sink vertex. These edges determine a unique path from the source to a sink. We can think of it as a switch in every vertex, which determines which way the water arriving to that vertex flows further. We are interested in determining either the sink the flow arrives, or the whole path, with as few questions as possible. The questions we can ask correspond to the vertices of the graph, and the answer describes the switch, i.e. tells which outgoing edge is in our given subset. Originally the problem was proposed by Soren Riis (who posed the question for pyramid graphs) in the following more general form. We are given a natural number k, and k questions can be asked in a round. The goal is to minimize the number of rounds. We completely solve this problem for complete t-ary trees. Also, for pyramid graphs we present some non-trivial partial results.

  13. The Conflict Pyramid: A Holistic Approach to Structuring Conflict Resolution in Schools

    Hakvoort, Ilse

    2010-01-01

    This paper examines how the conflict pyramid, originally defined and used by Richard Cohen, can be used as a model to describe the relations between different conflict resolution education programs and activities included in the programs. The central questions posed in the paper are: How can Richard Cohen's conflict pyramid be used as a model for…

  14. Pyramidal anchor stone from Baga waters of Goa, west coast of India

    Tripati, S.

    . Pyramidal anchor stones have an apex hole which goes up to the round hole, however Goa anchor stone has no such perforation, but, instead has a rectangular cutting on the apex. The anchor stone is compared with Greek pyramidal anchor stones, and probably...

  15. Morphological pyramids in multiresolution MIP rendering of large volume data: Survey and new results

    Roerdink, J. B. T. M.

    2005-01-01

    We survey and extend nonlinear signal decompositions based on morphological pyramids, and their application to multiresolution maximum intensity projection (MIP) volume rendering with progressive refinement and perfect reconstruction. The structure of the resulting multiresolution rendering algorithm is very similar to wavelet splatting. Several existing classes of pyramids are discussed, and their limitations indicated. To enhance the approximation quality of visualizations from reduced data...

  16. Neuronal chromatin changes in layer V pyramidal cells of somatomotor cortex after pyramidal tract lesions as demonstrated by [3H]actinomycin D binding

    Changes in chromatin structure of pyramidal tract neurons after medullary pyramidal tract lesions were examined autoradiographically utilizing [3H]actinomycin D (Act D) binding to nuclei in frozen sections of brain. After a right pyramidal tract lesion, the binding of Act D to nuclei of axotomized pyramidal neurons of somatomotor cortex layer V increased sharply at 1 and 5 days postoperation, compared with pyramidal cells of the left side or hippocampal control cells of the left hemisphere. At 3, 7, 9, and 11 days the axotomized cells showed significantly decreased binding compared with controls. The unoperated pyramidal cells showed a significantly decreased Act D binding at 2 h and 9 days postoperation compared with the ipsilateral hippocampal control cells. The data suggested that intrinsic neurons of the central nervous system had a response pattern of chromatin changes to axotomy that was basically similar to that of peripheral neurons (sensory ganglion cells). However, the response was compressed into the 1st week postoperation with only a brief reaction which might be correlated to axonal regeneration. This reaction was followed by a prolonged depression of Act D nuclear binding which may be associated with cellular atrophy

  17. Renal pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function

    Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis. To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine (99mTc-MAG3) scan. Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by 99mTc-MAG3 scan, of the obstructed kidney of ≥45% was considered normal and of ≤44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids. In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294). We observed that in obstructed kidneys the echogenicity

  18. Dendritic branching angles of pyramidal cells across layers of the juvenile rat somatosensory cortex.

    Leguey, Ignacio; Bielza, Concha; Larrañaga, Pedro; Kastanauskaite, Asta; Rojo, Concepción; Benavides-Piccione, Ruth; DeFelipe, Javier

    2016-09-01

    The characterization of the structural design of cortical microcircuits is essential for understanding how they contribute to function in both health and disease. Since pyramidal neurons represent the most abundant neuronal type and their dendritic spines constitute the major postsynaptic elements of cortical excitatory synapses, our understanding of the synaptic organization of the neocortex largely depends on the available knowledge regarding the structure of pyramidal cells. Previous studies have identified several apparently common rules in dendritic geometry. We study the dendritic branching angles of pyramidal cells across layers to further shed light on the principles that determine the geometric shapes of these cells. We find that the dendritic branching angles of pyramidal cells from layers II-VI of the juvenile rat somatosensory cortex suggest common design principles, despite the particular morphological and functional features that are characteristic of pyramidal cells in each cortical layer. J. Comp. Neurol. 524:2567-2576, 2016. © 2016 Wiley Periodicals, Inc. PMID:26850576

  19. Variation around a Pyramid theme: optical recombination and optimal use of photons

    Fauvarque, O; Fusco, T; Sauvage, J F

    2015-01-01

    We propose a new type of Wave Front Sensor (WFS) derived from the Pyramid WFS (PWFS). This new WFS, called the Flattened Pyramid-WFS (FPWFS), has a reduced Pyramid angle in order to optically overlap the four pupil images into an unique intensity. This map is then used to derive the phase information. In this letter this new WFS is compared to three existing WFSs, namely the PWFS, the Modulated PWFS (MPWFS) and the Zernike WFS (ZWFS) following tests about sensitivity, linearity range and low photon flux behavior. The FPWFS turns out to be more linear than a modulated pyramid for the high-spatial order aberrations but it provides an improved sensitivity compared to the non-modulated pyramid. The noise propagation may even be as low as the ZWFS for some given radial orders. Furthermore, the pixel arrangement being more efficient than for the PWFS, the FPWFS seems particularly well suited for high-contrast applications.

  20. The architectonic encoding of the minor lunar standstills in the horizon of the Giza pyramids.

    Hossam, M. K. Aboulfotouh

    The paper is an attempt to show the architectonic method of the ancient Egyptian designers for encoding the horizontal-projections of the moon's declinations during two events of the minor lunar standstills, in the design of the site-plan of the horizon of the Giza pyramids, using the methods of descriptive geometry. It shows that the distance of the eastern side of the second Giza pyramid from the north-south axis of the great pyramid encodes a projection of a lunar declination, when earth's obliquity-angle was ~24.10°. Besides, it shows that the angle of inclination of the causeway of the second Giza pyramid, of ~13.54° south of the cardinal east, encodes the projection of another lunar declination when earth's obliquity-angle reaches ~22.986°. In addition, it shows the encoded coordinate system in the site-plan of the horizon of the Giza pyramids.

  1. GaAs micro-pyramids serving as optical micro-cavities

    An efficient light-matter coupling requires high-quality (Q) micro-cavities with small mode volume. We suggest GaAs micro-pyramids placed on top of AlAs/GaAs distributed Bragg reflectors to be promising candidates. The pyramids were fabricated by molecular-beam epitaxy, electron-beam lithography and a subsequent wet-chemical etching process using a sacrificial AlAs layer. Measured Q-factors of optical modes in single pyramids reach values up to 650. A finite-difference time-domain simulation assuming a simplified cone-shaped geometry suggests possible Q-factors up to 3600. To enhance the light confinement in the micro-pyramids we intend to overgrow the pyramidal facets with a Bragg mirror--results of preliminary tests are given.

  2. Ethanol enhances neurosteroidogenesis in hippocampal pyramidal neurons by paradoxical NMDA receptor activation.

    Tokuda, Kazuhiro; Izumi, Yukitoshi; Zorumski, Charles F

    2011-07-01

    Using an antibody against 5α-reduced neurosteroids, predominantly allopregnanolone, we found that immunostaining in the CA1 region of rat hippocampal slices was confined to pyramidal neurons. This neurosteroid staining was increased following 15 min administration of 60 mm but not 20 mm ethanol, and the enhancement was blocked by finasteride and dutasteride, selective inhibitors of 5α-reductase, a key enzyme required for allopregnanolone synthesis. Consistent with a prior report indicating that N-methyl-D-aspartate (NMDA) receptor (NMDAR) activation can promote steroid production, we observed that D-2-amino-5-phosphonovalerate (APV), a competitive NMDAR antagonist, blocked the effects of 60 mm ethanol on staining. We previously reported that 60 mm ethanol inhibits the induction of long-term potentiation (LTP), a cellular model for memory formation, in the CA1 region. In the present study, LTP inhibition by 60 mm ethanol was also overcome by both the 5α-reductase inhibitors and by APV. Furthermore, the effects of ethanol on neurosteroid production and LTP were mimicked by a low concentration of NMDA (1 μm), and the ability of NMDA to inhibit LTP and to enhance neurosteroid staining was reversed by finasteride and dutasteride, as well as by APV. These results indicate that ethanol paradoxically enhances GABAergic neurosteroid production by activation of unblocked NMDARs and that acute LTP inhibition by ethanol represents a form of NMDAR-mediated metaplasticity. PMID:21734282

  3. Succeeding at the Bottom-of-the-Pyramid

    Boxenbaum, Eva; Olsen, Mette

    Hybrid organizational forms often rely on the initiative or collaboration of corporate actors, yet the role of these actors is rarely examined in detail. This paper examines corporate social entrepreneurship, which refers to the initiative of corporate actors to establish new, independent social...... ventures in the double pursuit of financial objectives and wider societal objectives. Through an empirical study, we investigate the strategies and practices that corporate social entrepreneurs employ to build radically new social ventures outside their firm. More specifically, we examine a successful...... initiative to build a social impact venture at the interface of a multi-national corporation and a hybrid organization that is operating on the Bottom-of-the-Pyramid market. Our study identifies how corporate social entrepreneurs dynamically use framing and organizational anchoring strategies to build...

  4. Photocurrent spectroscopy of site-controlled pyramidal quantum dots

    Mohan, A.; Nevou, L.; Gallo, P.; Dwir, B.; Rudra, A.; Kapon, E.; Faist, J.

    2012-07-01

    Intraband photocurrent spectroscopy of site-controlled pyramidal quantum dots by inserting them into the intrinsic region of n-i-n like quantum dot infrared photodetector structure is reported. The photovoltaic response is observed in the mid-infrared region. A peak responsivity of 0.4 mA/W at 120 meV (λ = 10 μm) is observed at 10 K at -2 V bias. The ability to engineer states in the conduction band of the QDs has been exploited to tune their photocurrent response from 10 μm to 18 μm with a narrow spectral width of Δλ/λ = 0.17.

  5. Silicon sensors with pyramidal structures for neutron imaging

    Kok, A.; Kohout, Z.; Hansen, T.-E.; Petersson, S.; Pospisil, S.; Rokne, J.; Slavicek, T.; Soligard, S.; Thungstrom, G.; Vykydal, Z.

    2014-04-01

    Neutron detection is a valuable tool in nuclear science research, homeland security, quality assurance in nuclear plants and medical applications. Recent developments and near future instrumentations in neutron imaging have a need for sensors with high spatial resolution, dynamic range, sensitivity and background discrimination. Silicon based neutron detectors can potentially fulfil these requirements. In this work, pad and pixel detectors with pyramidal micro-structures have been successfully fabricated that should have an improved detection efficiency when compared to conventional planar devices. Titanium di-boride (TiB2) and lithium fluoride (LiF) were deposited as the neutron converters. Excellent electrical performances were measured on both simple pad and pixel detectors. A selection of pad detectors was examined by alpha spectroscopy. Measurement with thermal neutrons from a 241Am-Be source shows an improvement in relative efficiency of up to 38% when compared to conventional planar devices.

  6. Silicon sensors with pyramidal structures for neutron imaging

    Neutron detection is a valuable tool in nuclear science research, homeland security, quality assurance in nuclear plants and medical applications. Recent developments and near future instrumentations in neutron imaging have a need for sensors with high spatial resolution, dynamic range, sensitivity and background discrimination. Silicon based neutron detectors can potentially fulfil these requirements. In this work, pad and pixel detectors with pyramidal micro-structures have been successfully fabricated that should have an improved detection efficiency when compared to conventional planar devices. Titanium di-boride (TiB2) and lithium fluoride (LiF) were deposited as the neutron converters. Excellent electrical performances were measured on both simple pad and pixel detectors. A selection of pad detectors was examined by alpha spectroscopy. Measurement with thermal neutrons from a 241Am-Be source shows an improvement in relative efficiency of up to 38% when compared to conventional planar devices

  7. Pyramide des âges et gestion des ressources humaines

    Godelier, Eric

    2007-01-01

    L'utilisation de la pyramide des âges dans les discours des directeurs de ressources humaines s'est développée au cours des années 1980. Elle renvoie au choix d'un critère de sélection de salariés jugés en sureffectif. Derrière l'âge et ses représentations, c'est bien la question de la capacité des salariés à s'adapter au changement de l'entreprise qui est posée. En définitive, il s'agit de savoir s'il existe des conditions démographiques au changement organisationnel.

  8. Mnemonic Functions for Nonlinear Dendritic Integration in Hippocampal Pyramidal Circuits.

    Kaifosh, Patrick; Losonczy, Attila

    2016-05-01

    We present a model for neural circuit mechanisms underlying hippocampal memory. Central to this model are nonlinear interactions between anatomically and functionally segregated inputs onto dendrites of pyramidal cells in hippocampal areas CA3 and CA1. We study the consequences of such interactions using model neurons in which somatic burst-firing and synaptic plasticity are controlled by conjunctive processing of these separately integrated input pathways. We find that nonlinear dendritic input processing enhances the model's capacity to store and retrieve large numbers of similar memories. During memory encoding, CA3 stores heavily decorrelated engrams to prevent interference between similar memories, while CA1 pairs these engrams with information-rich memory representations that will later provide meaningful output signals during memory recall. While maintaining mathematical tractability, this model brings theoretical study of memory operations closer to the hippocampal circuit's anatomical and physiological properties, thus providing a framework for future experimental and theoretical study of hippocampal function. PMID:27146266

  9. Mediterranean Diet Pyramid: A Proposal for Italian People

    Annunziata D'Alessandro

    2014-10-01

    Full Text Available Bread was a staple in the traditional Mediterranean diet of the early 1960s, as well as nowadays; however, it was a stone ground sourdough bread in Nicotera and probably in the Greek cohorts of the Seven Countries Study. In the present review, the nutritional characteristics of this food are analyzed in relation to its protective effects on coronary heart disease, metabolic diseases and cancer. According to our traditions, cultural heritage and scientific evidence, we propose that only cereal foods with low glycemic index (GI and rich in fiber have to be placed at the base of the Mediterranean diet pyramid, whereas refined grains and high GI starchy foods have to be sited at the top.

  10. The dendritic density field of a cortical pyramidal cell

    Hermann eCuntz

    2012-02-01

    Full Text Available Much is known about the computation in individual neurons in the cortical column. Also, the selective connectivity between many cortical neuron types has been studied in great detail. But due to the complexity of this microcircuitry its functional role within the cortical column remains a mystery. Some of the wiring behavior between neurons can be interpreted directly from their particular dendritic and axonal shapes. Here, I describe the dendritic density field as one key element that remains to be better understood. I sketch an approach to relate dendritic density fields in general to their underlying potential connectivity schemes. As an example, I show how the characteristic shape of a cortical pyramidal cell appears as a direct consequence of connecting inputs arranged in two separate parallel layers.

  11. Mediterranean diet pyramid: a proposal for Italian people.

    D'Alessandro, Annunziata; De Pergola, Giovanni

    2014-10-01

    Bread was a staple in the traditional Mediterranean diet of the early 1960s, as well as nowadays; however, it was a stone ground sourdough bread in Nicotera and probably in the Greek cohorts of the Seven Countries Study. In the present review, the nutritional characteristics of this food are analyzed in relation to its protective effects on coronary heart disease, metabolic diseases and cancer. According to our traditions, cultural heritage and scientific evidence, we propose that only cereal foods with low glycemic index (GI) and rich in fiber have to be placed at the base of the Mediterranean diet pyramid, whereas refined grains and high GI starchy foods have to be sited at the top. PMID:25325250

  12. Clinical results of neurotransmission SPECT in extra-pyramidal diseases

    We present some methodological aspects and clinical applications of dopamine D2 receptor and transporter SPECT using new radiotracers radiolabeled with iodine 123. The gamma camera quality control and standardisation has to be adapted to the small volume and deep location of striata, where receptors and transporters are present. Phantom containing hollow spheres of different diameters which can be filled with different amounts of 99mTc or 123I. The semi quantitation of receptor and transporter molecular concentration is based on an equilibrium binding model. According to this model, the binding potential (Bmax. Ka) is equal to the ratio between specific binding in the striatum and circulating activity in a reference region of interest in the occipital cortex. By comparing ECD and ILIS SPECT, it has been shown that striatal ILIS binding does not depend on the local perfusion. The clinical applications mainly concern the extra-pyramidal pathology: ILIS and IBZM SPECT are able to differentiate pre- and post-synaptic lesions. In Parkinson disease the nigrostriatal pathway is damaged and D2 receptors are normal or increased, as shown by normal or elevated IBZM or ILIS uptake. In other extra pyramidal degenerative diseases as progressive supra nuclear palsy or multiple system atrophy striatal D2 receptors are damaged as shown by decreased IBZM or ILIS uptake. In our experience, 88 per cent of patients are correctly classified by ILIS SPECT and 86 per cent with IBZM SPECT. Dopamine transporter SPECT with βCIT and PE2I provides an evaluation of the presynaptic neuronal density in the striatum. One can expect an help for the early diagnosis and the evaluation of Parkinson disease. Another potential application of dopaminergic neurotransmission SPECT is the evaluation of neuronal loss after hypoxo-ischemia. We conclude that dopaminergic neurotransmission SPECT using specific ligands should become a useful diagnosis tool to study a large number of brain dysfunctions. (author)

  13. Active appearance pyramids for object parametrisation and fitting.

    Zhang, Qiang; Bhalerao, Abhir; Dickenson, Edward; Hutchinson, Charles

    2016-08-01

    Object class representation is one of the key problems in various medical image analysis tasks. We propose a part-based parametric appearance model we refer to as an Active Appearance Pyramid (AAP). The parts are delineated by multi-scale Local Feature Pyramids (LFPs) for superior spatial specificity and distinctiveness. An AAP models the variability within a population with local translations of multi-scale parts and linear appearance variations of the assembly of the parts. It can fit and represent new instances by adjusting the shape and appearance parameters. The fitting process uses a two-step iterative strategy: local landmark searching followed by shape regularisation. We present a simultaneous local feature searching and appearance fitting algorithm based on the weighted Lucas and Kanade method. A shape regulariser is derived to calculate the maximum likelihood shape with respect to the prior and multiple landmark candidates from multi-scale LFPs, with a compact closed-form solution. We apply the 2D AAP on the modelling of variability in patients with lumbar spinal stenosis (LSS) and validate its performance on 200 studies consisting of routine axial and sagittal MRI scans. Intervertebral sagittal and parasagittal cross-sections are typically used for the diagnosis of LSS, we therefore build three AAPs on L3/4, L4/5 and L5/S1 axial cross-sections and three on parasagittal slices. Experiments show significant improvement in convergence range, robustness to local minima and segmentation precision compared with Constrained Local Models (CLMs), Active Shape Models (ASMs) and Active Appearance Models (AAMs), as well as superior performance in appearance reconstruction compared with AAMs. We also validate the performance on 3D CT volumes of hip joints from 38 studies. Compared to AAMs, AAPs achieve a higher segmentation and reconstruction precision. Moreover, AAPs have a significant improvement in efficiency, consuming about half the memory and less than 10% of

  14. Spatial Pyramid Pooling in Deep Convolutional Networks for Visual Recognition.

    He, Kaiming; Zhang, Xiangyu; Ren, Shaoqing; Sun, Jian

    2015-09-01

    Existing deep convolutional neural networks (CNNs) require a fixed-size (e.g., 224 × 224) input image. This requirement is "artificial" and may reduce the recognition accuracy for the images or sub-images of an arbitrary size/scale. In this work, we equip the networks with another pooling strategy, "spatial pyramid pooling", to eliminate the above requirement. The new network structure, called SPP-net, can generate a fixed-length representation regardless of image size/scale. Pyramid pooling is also robust to object deformations. With these advantages, SPP-net should in general improve all CNN-based image classification methods. On the ImageNet 2012 dataset, we demonstrate that SPP-net boosts the accuracy of a variety of CNN architectures despite their different designs. On the Pascal VOC 2007 and Caltech101 datasets, SPP-net achieves state-of-the-art classification results using a single full-image representation and no fine-tuning. The power of SPP-net is also significant in object detection. Using SPP-net, we compute the feature maps from the entire image only once, and then pool features in arbitrary regions (sub-images) to generate fixed-length representations for training the detectors. This method avoids repeatedly computing the convolutional features. In processing test images, our method is 24-102 × faster than the R-CNN method, while achieving better or comparable accuracy on Pascal VOC 2007. In ImageNet Large Scale Visual Recognition Challenge (ILSVRC) 2014, our methods rank #2 in object detection and #3 in image classification among all 38 teams. This manuscript also introduces the improvement made for this competition. PMID:26353135

  15. Epitaxial growth of μm-sized Cu pyramids on silicon

    Seyffarth, Susanne; Krebs, Hans-Ulrich

    2010-06-01

    Triangular and quadratic Cu pyramids were epitaxially grown on Si(111) and Si(100) substrates, respectively, by pulsed laser deposition at elevated substrate temperatures above 200°C as well as by post-annealing of closed Cu layers prepared at room temperature. In both cases, three-dimensional pyramids with edge lengths of up to 9 μm were obtained, as observed by scanning electron microscopy and atomic force microscopy. Although the macroscopic shape is a pyramid, microscopically the islands consist of columnar grains (with lateral sizes of only about 50 nm at 260°C). The size and shape of the pyramids can be controlled by the substrate used, the amount of material deposited, and the temperature during deposition or annealing. Additionally, first hints were found that the pyramids can be aligned by structuring the substrate. The formation of such large pyramids is explained by a fast diffusion of Cu atoms on Si over distances of some μm and a high jump probability to higher pyramid layers.

  16. Epitaxial growth of {mu}m-sized Cu pyramids on silicon

    Seyffarth, Susanne; Krebs, Hans-Ulrich [University of Goettingen (Germany). Institut fuer Materialphysik

    2010-06-15

    Triangular and quadratic Cu pyramids were epitaxially grown on Si(111) and Si(100) substrates, respectively, by pulsed laser deposition at elevated substrate temperatures above 200 C as well as by post-annealing of closed Cu layers prepared at room temperature. In both cases, three-dimensional pyramids with edge lengths of up to 9 {mu}m were obtained, as observed by scanning electron microscopy and atomic force microscopy. Although the macroscopic shape is a pyramid, microscopically the islands consist of columnar grains (with lateral sizes of only about 50 nm at 260 C). The size and shape of the pyramids can be controlled by the substrate used, the amount of material deposited, and the temperature during deposition or annealing. Additionally, first hints were found that the pyramids can be aligned by structuring the substrate. The formation of such large pyramids is explained by a fast diffusion of Cu atoms on Si over distances of some {mu}m and a high jump probability to higher pyramid layers. (orig.)

  17. New insight into the development of pyramidal structures on bombarded copper surfaces

    The morphological evolution of pyramids, developed on bombarded Cu surfaces, as a function of consecutive doses of normally incident mass-separated 12 keV Kr+ ions from 2.4 x 1016 up to 3 x 1019 ions/cm2 has been studied. Three types of polycrystalline sample, with initial surface topography due to distinct polishing procedures, were used. Three main conclusions were reached. (a) The presence on the unbombarded surfaces of asperities is very important, there being a 1:1 correlation between pyramids and pre-existing asperities, at least for the surfaces as here prepared. (b) In agreement with the predictions of other authors, all pyramids disappeared at high enough doses with all specimens. Pyramids are therefore not an equilibrium structure. (c) Features with a mushroom-like shape were observed which can, under certain circumstances, be an intermediate stage towards the final pyramidal shapes but are, more generally, an indication of the existence of tertiary effects. The results, taken as a whole, suggest a model based on the evolution of asperities by a combination of primary sputtering with further shape modification due to secondary and tertiary effects, i.e. due to particle trajectories as influenced by the pyramids and the grooves underlying the pyramids. (author)

  18. Modulation of hard x-ray beam profiles by Borrmann pyramid

    Spatial modulation of hard x-ray beam profiles is reported, using the 'Borrmann pyramid' formed in dual Bragg diffraction of a single crystal, where a small angular change of the incident beam is magnified to span the entire pyramid base. As an attempt, it is demonstrated using hard x rays by (1) the linear shift of a micrometer sized mask; (2) the partial blockade of a two micron beam; and (3) the millimeter shadow of a nanoscale gold strip, which shows the potential application of Borrmann pyramids in the form of an enlarged x-ray image

  19. Multi-dimensional pyramidal traveling fronts in the Allen-Cahn equations

    黒川, 由生; Kurokawa, Yu; 谷口, 雅治; Taniguchi, Masaharu

    2011-01-01

    This paper studies traveling front solutions of pyramidal shapes in the Allen-Cahn equation in $\\mathbb{R}^{N}$ with $N\\geq 3$.It is well known that two-dimensional V-form traveling fronts and three-dimensional pyramidal traveling fronts exist and are stable. The aim of this paper is to show that for $N\\geq 4$,there exist $N$-dimensional pyramidal traveling fronts.We construct a supersolution and a subsolution, and find a pyramidaltraveling front solution between them. For the construction o...

  20. Epitaxial growth of μm-sized Cu pyramids on silicon

    Seyffarth, Susanne; Krebs, Hans-Ulrich

    2010-01-01

    Triangular and quadratic Cu pyramids were epitaxially grown on Si(111) and Si(100) substrates, respectively, by pulsed laser deposition at elevated substrate temperatures above 200°C as well as by post-annealing of closed Cu layers prepared at room temperature. In both cases, three-dimensional pyramids with edge lengths of up to 9 μm were obtained, as observed by scanning electron microscopy and atomic force microscopy. Although the macroscopic shape is a pyramid, microscopically the islands ...

  1. Searching for possible hidden chambers in the Pyramid of the Sun

    Alfaro, R.; Belmont, E.; Grabski, V.; Manzanilla, L.; Martinez-Davalos, A.; Menchaca-Rocha, A.; Moreno, M.; Sandoval, A.

    The Pyramid of the Sun, at Teotihuacan, Mexico, is being searched for possible hidden chambers, using a muon tracking technique inspired in the experiment carried out by Luis Alvarez over 30 years ago at the Chephren Pyramid, in Giza. A fortunate similarity between this monument and the Pyramid of the Sun is a tunnel, running 8 m below the base and ending close to the symmetry axis, which permits the use muon attenuation measurements. A brief account of the project, including planning, detector design, construction and simulations, as well as the current status of the project is presented

  2. The offset-midpoint traveltime pyramid of P-waves in homogeneous orthorhombic media

    Hao, Qi

    2016-07-18

    The offset-midpoint traveltime pyramid describes the diffraction traveltime of a point diffractor in homogeneous media. We have developed an analytic approximation for the P-wave offset-midpoint traveltime pyramid for homogeneous orthorhombic media. In this approximation, a perturbation method and the Shanks transform were implemented to derive the analytic expressions for the horizontal slowness components of P-waves in orthorhombic media. Numerical examples were shown to analyze the proposed traveltime pyramid formula and determined its accuracy and the application in calculating migration isochrones and reflection traveltime. The proposed offset-midpoint traveltime formula is useful for Kirchhoff prestack time migration and migration velocity analysis for orthorhombic media.

  3. Introduction of a pyramid guiding process for general musculoskeletal physical rehabilitation

    Stark Timothy W

    2006-06-01

    Full Text Available Abstract Successful instruction of a complicated subject as Physical Rehabilitation demands organization. To understand principles and processes of such a field demands a hierarchy of steps to achieve the intended outcome. This paper is intended to be an introduction to a proposed pyramid scheme of general physical rehabilitation principles. The purpose of the pyramid scheme is to allow for a greater understanding for the student and patient. As the respected Food Guide Pyramid accomplishes, the student will further appreciate and apply supported physical rehabilitation principles and the patient will understand that there is a progressive method to their functional healing process.

  4. Region-specific spike frequency acceleration in Layer 5 pyramidal neurons mediated by Kv1 subunits

    Miller, Mark N; Okaty, Benjamin W.; Nelson, Sacha B.

    2008-01-01

    Separation of the cortical sheet into functionally distinct regions is a hallmark of neocortical organization. Cortical circuit function emerges from afferent and efferent connectivity, local connectivity within the cortical microcircuit, and the intrinsic membrane properties of neurons that comprise the circuit. While localization of functions to particular cortical areas can be partially accounted for by regional differences in both long range and local connectivity, it is unknown whether t...

  5. Phase ambiguity solution with the Pyramid Phasing Sensor

    Pinna, E.; Esposito, S.; Puglisi, A.; Pieralli, F.; Myers, R. M.; Busoni, L.; Tozzi, A.; Stefanini, P.

    2006-06-01

    In the technological development for the ELTs, one of the key activities is the phasing and alignment of the primary mirror segments. To achieve the phasing accuracy of a small fraction of the wavelength, an optical sensor is required. In 2005 has been demonstrated that the Pyramid Wavefront Sensor can be employed in closed loop to correct simultaneously piston, tip and tilt errors of segmented mirror. The Pyramid Phasing Sensor (PYPS) is based on the sensing of phase step on the segment edges; this kind of phasing sensors have the common limitation of the signal ambiguity induced by the phase periodicity of πδ/λ on the mirror surface step δ, when the wavelength λ is used for the sensing. In this paper we briefly describe three different techniques that allow to solve the phase ambiguity with PYPS. As first we present experimental results on the two wavelengths closed loop procedure proposed by Esposito in 2001; in the laboratory test the multi-wavelength procedure allowed to exceed the sensor capture range of +/-λ/2 and simultaneously retrieve the differential piston of the 32 mirror segments starting from random positions in a 3.2 λ wavefront range, the maximum allowed by the mirror stroke. Then we propose two new techniques based respectively on the segment and wavelength sweep. The Segment Sweep Technique (SST) has been successfully applied during the experimental tests of PYPS at the William Herschel Telescope, when 13 segments of the NAOMI DM has been phased starting from a random position in a 15λ range. The Wavelength Sweep Technique (WST) has been subject of preliminary tests in the Arcetri laboratories in order to prove the concept. Each technique has different capture range, accuracy and operation time, so that each can solve different tasks required to an optical phasing sensor in the ELT application. More in detail the WST and SST could be used combined for the first mirror phasing when the calibration required for the closed loop operations

  6. Morphological pyramids in multiresolution MIP rendering of large volume data : Survey and new results

    Roerdink, Jos B.T.M.

    2005-01-01

    We survey and extend nonlinear signal decompositions based on morphological pyramids, and their application to multiresolution maximum intensity projection (MIP) volume rendering with progressive refinement and perfect reconstruction. The structure of the resulting multiresolution rendering algorith

  7. Pyramid shape of polymer solar cells: a simple solution to triple efficiency

    Pyramid-shaped polymer solar cells fabricated on flexible substrates were investigated. Effective light trapping can be realized due to light reflection in all 360° directions, and 100% space utilization is achieved when assembled into arrays. The power conversion efficiency is enhanced by 200% ([60]PCBM as the acceptor) and 260% ([70]PCBM as the acceptor) with a dihedral angle of 30° between the opposite sides of the pyramid compared with a planar device, and a high Voc of 3.5 V in series connection is obtained. Considering the material utilization, an angle of 90° for pyramid-shaped polymer solar cells is proposed. Pyramid-shaped polymer solar cells are particularly suitable for installation on roof of vehicles and houses, which have limited surface area. (paper)

  8. Indian Reservations, Pyramid lake tribal boundary, reno/sparks tribal boundary, Published in 2006, Washoe County.

    NSGIC GIS Inventory (aka Ramona) — This Indian Reservations dataset, was produced all or in part from Published Reports/Deeds information as of 2006. It is described as 'Pyramid lake tribal boundary,...

  9. A muon detector to be installed at the Pyramid of the Sun

    Is the Pyramid of the Sun at Teotihuacan a mausoleum, or just a ceremonial monument? A similar question inspired Luis Alvarez over 30 years ago to carry out his famous muon detection experiment at the Chephren Pyramid, in Giza. A fortunate similarity between this monument and the Pyramid of the Sun is a tunnel, running 8 m below the base and ending close to the symmetry axis, which allows us to emulate Alvarez in a search for possible hidden chambers in one of the largest pyramids in Latin America. Here we elaborate on what is known about this monument, on a description of the proposed detector design, and its expected performance based on simulations. (Author)

  10. A muon detector to be installed at the Pyramid of the Sun

    Alfaro, R.; Belmont M, E.; Cervantes, A.; Grabski, V.; Lopez R, J.M.; Manzanilla, L.; Martinez D, A.; Moreno, M.; Menchaca R, A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico D.F. (Mexico)

    2003-07-01

    Is the Pyramid of the Sun at Teotihuacan a mausoleum, or just a ceremonial monument? A similar question inspired Luis Alvarez over 30 years ago to carry out his famous muon detection experiment at the Chephren Pyramid, in Giza. A fortunate similarity between this monument and the Pyramid of the Sun is a tunnel, running 8 m below the base and ending close to the symmetry axis, which allows us to emulate Alvarez in a search for possible hidden chambers in one of the largest pyramids in Latin America. Here we elaborate on what is known about this monument, on a description of the proposed detector design, and its expected performance based on simulations. (Author)

  11. The azimuth-dependent offset-midpoint traveltime pyramid in 3D HTI media

    Hao, Qi

    2013-09-22

    Analytical representation of offset-midpoint traveltime equation is very important for pre-stack Kirchhoff migration and velocity inversion in anisotropic media. For VTI media, the offset-midpoint traveltime resembles the shape of Cheop\\'s pyramid. In this study, we extend the offset-midpoint traveltime pyramid to the case of 3D HTI media. We employ the stationary phase method to derive the analytical representation of traveltime equation, and then use Shanks transformation to improve the accuracy of horizontal and vertical slownesses. The traveltime pyramid is derived in both the depth- and time-domain. Numerical examples indicate that the azimuthal characteristics of both the traveltime pyramid and the migration isochrones are very obvious in HTI media due to the effect of anisotropy.

  12. High-order Finite Elements on Pyramids: Approximation Spaces, Unisolvency and Exactness

    Nigam, Nilima; Phillips, Joel

    2010-01-01

    We present a family of high-order finite element approximation spaces on a pyramid, and associated unisolvent degrees of freedom. These spaces consist of rational basis functions. We establish conforming, exactness and polynomial approximation properties.

  13. Plasmon hybridization in pyramidal metamaterials: a route towards ultra-broadband absorption

    Lobet, Michael; Sarrazin, Michael; Deparis, Olivier; Henrard, Luc

    2014-01-01

    Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically and, to a less extent, laterally coupled plasmonic resonators. Based on detailed numerical simulations, we demonstrate that plasmon hybridization between such resonators helps in achieving ultra-broadband absorption. The dipolar modes of individual resonators are shown to be prominent in the electromagnetic coupling mechanism. Lateral coupling between adjacent pyramids and vertical coupling between alternating layers are proven to be key parameters for tuning of plasmon hybridization. Following optimization, the operational bandwidth of Au/Ge pyramids, i.e. the bandwidth within which absorption is higher than 90%, extends over a 0.2-5.8 micrometers wavelength range, i.e. from UV-visible to mid-infrared, and total absorption (integrated over the operatio...

  14. Rate-distortion optimised video transmission using pyramid vector quantisation.

    Bokhari, Syed; Nix, Andrew R; Bull, David R

    2012-08-01

    Conventional video compression relies on interframe prediction (motion estimation), intra frame prediction and variable-length entropy encoding to achieve high compression ratios but, as a consequence, produces an encoded bitstream that is inherently sensitive to channel errors. In order to ensure reliable delivery over lossy channels, it is necessary to invoke various additional error detection and correction methods. In contrast, techniques such as Pyramid Vector Quantisation have the ability to prevent error propagation through the use of fixed length codewords. This paper introduces an efficient rate distortion optimisation algorithm for intra-mode PVQ which offers similar compression performance to intra H.264/AVC and Motion JPEG 2000 while offering inherent error resilience. The performance of our enhanced codec is evaluated for HD content in the context of a realistic (IEEE 802.11n) wireless environment. We show that PVQ provides high tolerance to corrupted data compared to the state of the art while obviating the need for complex encoding tools. PMID:22453639

  15. Quantitative trait loci pyramiding for fruit quality traits in tomato.

    Sacco, Adriana; Di Matteo, Antonio; Lombardi, Nadia; Trotta, Nikita; Punzo, Biancavaleria; Mari, Angela; Barone, Amalia

    2013-01-01

    Fruit quality is a major focus for most conventional and innovative tomato breeding strategies, with particular attention being paid to fruit antioxidant compounds. Tomatoes represent a major contribution to dietary nutrition worldwide and a reservoir of diverse antioxidant molecules. In a previous study, we identified two Solanum pennellii introgression lines (IL7-3 and IL12-4) harbouring quantitative trait loci (QTL) that increase the content of ascorbic acid (AsA), phenols and soluble solids (degrees Brix; °Bx) in tomato fruit. The purpose of the present work was to pyramid into cultivated varieties the selected QTL for enhanced antioxidant and °Bx content. To better understand the genetic architecture of each QTL, the two ILs were crossed to the recurrent parent M82 (ILH7-3 and ILH12-4) and between them (ILH7-3+12-4). F1 hybrids (ILH7-3+12-4) were then selfed up to obtain F3 progenies in order to stabilize the favourable traits at the homozygous condition. Species-specific molecular markers were identified for each introgressed region and allowed us to select four F2 genotypes carrying both introgressions at the homozygous condition. The F3 double homozygous plants displayed AsA, total phenols and °Bx content significantly higher than M82. Therefore, they may represent suitable genetic material for breeding schemes aiming to increase antioxidant content in tomato fruit. PMID:23316114

  16. Synaptically evoked dendritic action potentials in rat neocortical pyramidal neurons.

    Schwindt, P C; Crill, W E

    1998-05-01

    In a previous study iontophoresis of glutamate on the apical dendrite of layer 5 pyramidal neurons from rat neocortex was used to identify sites at which dendritic depolarization evoked small, prolonged Ca2+ spikes and/or low-threshold Na+ spikes recorded by an intracellular microelectrode in the soma. These spikes were identified as originating in the dendrite. Here we evoke similar dendritic responses by electrical stimulation of presynaptic elements near the tip of the iontophoretic electrode with the use of a second extracellular electrode. In 9 of 12 recorded cells, electrically evoked excitatory postsynaptic potentials (EPSPs) above a minimum size triggered all-or-none postsynaptic responses similar to those evoked by dendritic glutamate iontophoresis at the same site. Both the synaptically evoked and the iontophoretically evoked depolarizations were abolished reversibly by blockade of glutamate receptors. In all recorded cells, the combination of iontophoresis and an EPSP, each of which was subthreshold for the dendritic spike when given alone, evoked a dendritic spike similar to that evoked by a sufficiently large iontophoresis. In one cell tested, dendritic spikes could be evoked by the summation of two independent subthreshold EPSPs evoked by stimulation at two different locations. We conclude that the dendritic spikes are not unique to the use of glutamate iontophoresis because similar spikes can be evoked by EPSPs. We discuss the implications of these results for synaptic integration and for the interpretation of recorded synaptic potentials. PMID:9582218

  17. MAP spatial pyramid mean shift for object tracking

    Han, Xiaobo; Zhang, Peng; Li, Houqiang

    2010-07-01

    Mean Shift is popular in object tracking due to its simplicity and efficiency. It finds local maximum of the similarity measure between the target model and target candidate, and works well in many situations. However, it suffers from two aspects. First, Mean Shift tracker ignores background knowledge. As a result, it may fail when the background color is similar to that of the target or the initial target region contains too much background. Second, Mean Shift tracker omits the geometric structure with a global color histogram as the target model. Therefore, it may not work in the case of partial occlusion. To solve the first problem, we introduce background color histogram into a MAP formulation. To address the second problem, we divide the target into hierarchical blocks. These blocks are described with a histogram each but tracked as a whole. The two threads lead to a new algorithm, named MAP spatial pyramid (MAP-SP) Mean Shift. The efficiency of MAP-SP Mean Shift is demonstrated via comparative experiments on both standard and our own video sequences

  18. Thalamocortical input onto layer 5 pyramidal neurons measured using quantitative large-scale array tomography

    Jong-Cheol eRah; Erhan eBas; Jennifer eColonell; Yuriy eMishchenko; Bill eKarsh; Fetter, Richard D.; Myers, Eugene W; Chklovskii, Dmitri B.; Karel eSvoboda; Harris, Timothy D.; Isaac, John T. R.

    2013-01-01

    The subcellular locations of synapses on pyramidal neurons strongly influences dendritic integration and synaptic plasticity. Despite this, there is little quantitative data on spatial distributions of specific types of synaptic input. Here we use array tomography (AT), a high-resolution optical microscopy method, to examine thalamocortical (TC) input onto layer 5 pyramidal neurons. We first verified the ability of AT to identify synapses using parallel electron microscopic analysis of TC syn...

  19. Color center fluorescence and spin manipulation in single crystal, pyramidal diamond tips

    Nelz, Richard; Opaluch, Oliver; Sonusen, Selda; Savenko, Natalia; Podgursky, Vitali; Neu, Elke

    2016-01-01

    We investigate bright fluorescence of nitrogen (NV)- and silicon-vacancy color centers in pyramidal, single crystal diamond tips which are commercially available as atomic force microscope probes. We coherently manipulate NV electronic spin ensembles with $T_2 = 7.7(3)\\,\\mu$s. Color center lifetimes in different tip heights indicate effective refractive index effects and quenching. Using numerical simulations, we verify enhanced photon rates from emitters close to the pyramid apex; a situation promising for scanning probe sensing.

  20. Resonance enhancement effects in Raman-enhancing pyramid-like V-shape groove microstructures

    Mechler, M.; Kukhlevsky, S. V.; Mechler, A.; McNaughton, D

    2009-01-01

    Microscopic pyramidal pits in a reflective surface, a geometry similar to a retroreflector, are frequently used to enhance signal strength. The enhancement effect is generally attributed to surface plasmons, however, the sub-wavelength to near-wavelength dimensions of the pyramidal 3D geometry suggest contributions from diffraction and near-field effects. Our theoretical analysis of the light intensity distribution in the similar (but simpler) 2D geometry assuming a perfect conductor screen, ...

  1. Length of Chain in Pyramidal Firms towards Expropriation of Minority Interest

    Irfah Najihah Basir Malan; Norhana Salamudin; Noryati Ahmad

    2015-01-01

    It is documented that there is a large divergence of cash flow rights and control rights in ownership concentrated corporations whereby power lies in the hands of the ultimate controlling shareholder especially for Malaysian pyramidal firms. The divergence of these two rights via length of chain leads to the expropriation of minority shareholders interest. Thus, this study aims to examine the factors influencing the length of chain of Malaysian pyramidal firms implying expropriation of minori...

  2. Computed tomography imaging of the pyramidal lobe of the thyroid gland

    The pyramidal lobe of the thyroid gland is a normal anatomical variant found frequently in the general population. This structure consists of normal thyroid tissue located in the upper part of the thyroid isthmus, extending upward in the form of a fibrous chord that connects it to the foramen caecum at the bottom of the tongue. This paper reviews thyroid anatomy and embryology, and highlights the main features of the pyramidal lobe, including the anatomy, epidemiology and computed tomography imaging.

  3. Improvement of quantum efficiency using surface texture of solar cell in the form of pyramid

    The work presented in this paper concerns a detailed study about the light transmission through textured surfaces in a surface made up of pyramids [1, 2]. We investigate to what extent and under what conditions we want to take advantage of ray incidence five times and more [3, 4]. It is found that these analyses can be used to determine the optimal surface texture, which provides the best light trapping for solar cells in terms of the total internal reflection occurring in the high-index medium at incidence angles larger than the nominal critical angle [5-11]. One of the main contributions of this paper is the analysis and quantification of the influence of the opening between the heads of the two closest pyramids in textured surface for solar cells and its application to the photovoltaic parameters, such as the quantum efficiency. In this model, we show that the material can have five and more successive incident ray absorptions instead of three currently, where we changed the direction of the reflected ray, by varying the angle between the two neighbouring pyramids, the incidence angle, the opening between the heads of the two closest pyramids and their height. Thus, an angle between the two neighbouring pyramids varies between 20 and 12° and an angle of incidence varies between 80 and 84°. For these values of the angle between the two neighbouring pyramids and incidence angle, the opening between the heads of the two closest pyramids varied respectively from 3.53 to 2.10 μm for a pyramid height of 10 μm. This leads to a substantial increase of the quantum efficiency, thus the photovoltaic efficiency

  4. Effect of Pyramidal Dome Geometry on the Acoustical Characteristics in A Mosque

    Dg. H. Kassim; A. Putra; M. J. M. NOR; N.S. Muhammad

    2014-01-01

    As an important symbol in Islam, a mosque is built with architectural grandeur. Among the characteristics is its high ceiling and it is usually constructed with a typical spherical dome shape. Some mosques, however, are influenced by the local culture and the dome can be of a different shape, such as pyramidal, as found in mosques in Malacca, Malaysia. This paper presents an assessment of the internal acoustical characteristics of a mosque having a pyramidal dome. The study is conducted by me...

  5. High-Order Optimal Edge Elements for Pyramids, Prisms and Hexahedra

    Bergot, Morgane; Duruflé, Marc

    2013-01-01

    Edge elements are a popular method to solve Maxwell's equations especially in time-harmonic domain. However, when non-affine elements are considered, elements of the Nedelec's first family are not providing an optimal rate of the convergence of the numerical solution toward the solution of the exact problem in H(curl)-norm. We propose new finite element spaces for pyramids, prisms, and hexahedra in order to recover the optimal convergence. In the particular case of pyramids, a comparison with...

  6. Fundamentals of layered nanoparticle covered pyramidal structures formed on nickel during femtosecond laser surface interactions

    Zuhlke, Craig A., E-mail: czuhlke11@gmail.com; Anderson, Troy P., E-mail: troy.anderson@unl.edu; Alexander, Dennis R., E-mail: dalexander1@unl.edu

    2013-10-15

    The formation of nanoparticle covered pyramidal structures using femtosecond laser pulses with a fluence near the ablation threshold is reported for the first time. These unique structures form through a combination of preferential ablation of flat regions around the pyramids and redeposition of nanoparticles created during the ablation process. The structures are demonstrated on nickel and stainless steel 316. When produced by rastering Gaussian pulses across the sample, layers of nanoparticles join together by sintering to form unique layered shells.

  7. A pliocene cliff-line around the Giza Pyramids Plateau, Egypt

    Aigner, Thomas

    1982-01-01

    Aigner, T., 1983. A Pliocene cliff-line around the Giza Pyramids Plateau, Egypt. Palaeogeogr., Palaeoclimatol., Palaeoecol., 4 2 : 313—322. Escarpments bordering the Giza Pyramids Plateau represent the cliff-line of a Pliocene transgression up the pre-Nile ("Eonile") Valley. Geomorphologically, a limestone cliff can be distinguished from a slip-block shore associated with a distinct fining-up sequence. Differences in bedrock lithology and in structure (Joint pattern, faults) are morphogen...

  8. Fundamentals of layered nanoparticle covered pyramidal structures formed on nickel during femtosecond laser surface interactions

    The formation of nanoparticle covered pyramidal structures using femtosecond laser pulses with a fluence near the ablation threshold is reported for the first time. These unique structures form through a combination of preferential ablation of flat regions around the pyramids and redeposition of nanoparticles created during the ablation process. The structures are demonstrated on nickel and stainless steel 316. When produced by rastering Gaussian pulses across the sample, layers of nanoparticles join together by sintering to form unique layered shells.

  9. Intracortical circuits of pyramidal neurons reflect their long-range axonal targets

    Brown, Solange P.; Hestrin, Shaul

    2009-01-01

    Cortical columns generate separate streams of information that are distributed to numerous cortical and subcortical brain regions1. We asked whether local intracortical circuits reflect these different processing streams by testing if the intracortical connectivity among pyramids reflects their long-range axonal targets. We recorded simultaneously from up to four retrogradely labelled pyramids that projected to the superior colliculus, the contralateral striatum or the contralateral cortex to...

  10. Moving Toward the Food Guide Pyramid: Implications for U.S. Agriculture

    Young, C. Edwin; Kantor, Linda Scott

    1999-01-01

    Recent studies show that average diets differ considerably from Food Guide Pyramid recommendations. The gap between current consumption and recommendations is particularly large for caloric sweeteners, fats and oils, fruits, and certain vegetables, notably dark-green leafy and deep-yellow vegetables, and dry beans, peas, and lentils. The change in food consumption needed to meet Food Guide Pyramid serving recommendations will result in adjustments in U.S. agricultural production, trade, nonfo...

  11. Two-Sided Pyramid Wavefront Sensor in the Direct Phase Mode

    Phillion, D; Baker, K

    2006-04-12

    The two-sided pyramid wavefront sensor has been extensively simulated in the direct phase mode using a wave optics code. The two-sided pyramid divides the focal plane so that each half of the core only interferes with the speckles in its half of the focal plane. A relayed image of the pupil plane is formed at the CCD camera for each half. Antipodal speckle pairs are separated so that a pure phase variation causes amplitude variations in the two images. The phase is reconstructed from the difference of the two amplitudes by transforming cosine waves into sine waves using the Hilbert transform. There are also other corrections which have to be applied in Fourier space. The two-sided pyramid wavefront sensor performs extremely well: After two or three iterations, the phase error varies purely in y. The two-sided pyramid pair enables the phase to be completely reconstructed. Its performance has been modeled closed loop with atmospheric turbulence and wind. Both photon noise and read noise were included. The three-sided and four-sided pyramid wavefront sensors have also been studied in direct phase mode. Neither performs nearly as well as does the two-sided pyramid wavefront sensor.

  12. Pyramidal cells in prefrontal cortex: comparative observations reveal unparalleled specializations in neuronal structure among primate species.

    Guy eElston

    2011-02-01

    Full Text Available The most ubiquitous neuron in the cerebral cortex, the pyramidal cell, is characterised by markedly different dendritic structure among different cortical areas. The complex pyramidal cell phenotype in granular prefrontal cortex (gPFC of higher primates endows specific biophysical properties and patterns of connectivity, which differ to those in other cortical regions. However, within the gPFC, data have been sampled from only a select few cortical areas. The gPFC of species such as human and macaque monkey includes more than 10 cortical areas. It remains unknown as to what degree pyramidal cell structure may vary among these cortical areas. Here we undertook a survey of pyramidal cells in the dorsolateral, medial and orbital gPFC of cercopethicid primates. We found marked heterogeneity in pyramidal cell structure within and between these regions. Moreover, trends for gradients in neuronal complexity varied among species. As neuron structure determines it’s computational abilities and memory storage capacity and connectivity, we propose that these specializations in the pyramidal cell phenotype are an important determinant of species specific executive cortical functions in primates.

  13. Active dendrites regulate the impact of gliotransmission on rat hippocampal pyramidal neurons.

    Ashhad, Sufyan; Narayanan, Rishikesh

    2016-06-01

    An important consequence of gliotransmission, a signaling mechanism that involves glial release of active transmitter molecules, is its manifestation as N-methyl-d-aspartate receptor (NMDAR)-dependent slow inward currents in neurons. However, the intraneuronal spatial dynamics of these events or the role of active dendrites in regulating their amplitude and spatial spread have remained unexplored. Here, we used somatic and/or dendritic recordings from rat hippocampal pyramidal neurons and demonstrate that a majority of NMDAR-dependent spontaneous slow excitatory potentials (SEP) originate at dendritic locations and are significantly attenuated through their propagation across the neuronal arbor. We substantiated the astrocytic origin of SEPs through paired neuron-astrocyte recordings, where we found that specific infusion of inositol trisphosphate (InsP3) into either distal or proximal astrocytes enhanced the amplitude and frequency of neuronal SEPs. Importantly, SEPs recorded after InsP3 infusion into distal astrocytes exhibited significantly slower kinetics compared with those recorded after proximal infusion. Furthermore, using neuron-specific infusion of pharmacological agents and morphologically realistic conductance-based computational models, we demonstrate that dendritically expressed hyperpolarization-activated cyclic-nucleotide-gated (HCN) and transient potassium channels play critical roles in regulating the strength, kinetics, and compartmentalization of neuronal SEPs. Finally, through the application of subtype-specific receptor blockers during paired neuron-astrocyte recordings, we provide evidence that GluN2B- and GluN2D-containing NMDARs predominantly mediate perisomatic and dendritic SEPs, respectively. Our results unveil an important role for active dendrites in regulating the impact of gliotransmission on neurons and suggest astrocytes as a source of dendritic plateau potentials that have been implicated in localized plasticity and place cell

  14. Calcium Carbonate Nucleation in an Alkaline Lake Surface Water, Pyramid Lake, Nevada, USA

    Reddy, M.M.; Hoch, A.

    2012-01-01

    Calcium concentration and calcite supersaturation (??) needed for calcium carbonate nucleation and crystal growth in Pyramid Lake (PL) surface water were determined during August of 1997, 2000, and 2001. PL surface water has ?? values of 10-16. Notwithstanding high ??, calcium carbonate growth did not occur on aragonite single crystals suspended PL surface water for several months. However, calcium solution addition to PL surface-water samples caused reproducible calcium carbonate mineral nucleation and crystal growth. Mean PL surface-water calcium concentration at nucleation was 2.33 mM (n = 10), a value about nine times higher than the ambient PL surface-water calcium concentration (0.26 mM); mean ?? at nucleation (109 with a standard deviation of 8) is about eight times the PL surface-water ??. Calcium concentration and ?? regulated the calcium carbonate formation in PL nucleation experiments and surface water. Unfiltered samples nucleated at lower ?? than filtered samples. Calcium concentration and ?? at nucleation for experiments in the presence of added particles were within one standard deviation of the mean for all samples. Calcium carbonate formation rates followed a simple rate expression of the form, rate (mM/min) = A (??) + B. The best fit rate equation "Rate (?? mM/?? min) = -0.0026 ?? + 0.0175 (r = 0.904, n = 10)" was statistically significant at greater than the 0.01 confidence level and gives, after rearrangement, ?? at zero rate of 6.7. Nucleation in PL surface water and morphology of calcium carbonate particles formed in PL nucleation experiments and in PL surface-water samples suggest crystal growth inhibition by multiple substances present in PL surface water mediates PL calcium carbonate formation, but there is insufficient information to determine the chemical nature of all inhibitors. ?? 2011 U.S. Government.

  15. EPSPs Measured in Proximal Dendritic Spines of Cortical Pyramidal Neurons.

    Acker, Corey D; Hoyos, Erika; Loew, Leslie M

    2016-01-01

    EPSPs occur when the neurotransmitter glutamate binds to postsynaptic receptors located on small pleomorphic membrane protrusions called dendritic spines. To transmit the synaptic signal, these potentials must travel through the spine neck and the dendritic tree to reach the soma. Due to their small size, the electrical behavior of spines and their ability to compartmentalize electrical signals has been very difficult to assess experimentally. In this study, we developed a method to perform simultaneous two-photon voltage-sensitive dye recording with two-photon glutamate uncaging in order to measure the characteristics (amplitude and duration) of uncaging-evoked EPSPs in single spines on the basal dendrites of L5 pyramidal neurons in acute brain slices from CD1 control mice. We were able to record uncaging-evoked spine potentials that resembled miniature EPSPs at the soma from a wide range of spine morphologies. In proximal spines, these potentials averaged 13.0 mV (range, 6.5-30.8 mV; N = 20) for an average somatic EPSP of 0.59 mV, whereas the mean attenuation ratio (spine/soma) was found to be 25.3. Durations of spine EPSP waveforms were found to be 11.7 ms on average. Modeling studies demonstrate the important role that spine neck resistance (R neck) plays in spine EPSP amplitudes. Simulations used to estimate R neck by fits to voltage-sensitive dye measurements produced a mean of 179 MΩ (range, 23-420 MΩ; N = 19). Independent measurements based on fluorescence recovery after photobleaching of a cytosolic dye from spines of the same population of neurons produced a mean R neck estimate of 204 MΩ (range, 52-521 MΩ; N = 34). PMID:27257618

  16. Developmental profile of localized spontaneous Ca(2+) release events in the dendrites of rat hippocampal pyramidal neurons.

    Miyazaki, Kenichi; Manita, Satoshi; Ross, William N

    2012-12-01

    Recent experiments demonstrate that localized spontaneous Ca(2+) release events can be detected in the dendrites of pyramidal cells in the hippocampus and other neurons (J. Neurosci. 29 (2009) 7833-7845). These events have some properties that resemble ryanodine receptor mediated "sparks" in myocytes, and some that resemble IP(3) receptor mediated "puffs" in oocytes. They can be detected in the dendrites of rats of all tested ages between P3 and P80 (with sparser sampling in older rats), suggesting that they serve a general signaling function and are not just important in development. However, in younger rats the amplitudes of the events are larger than the amplitudes in older animals and almost as large as the amplitudes of Ca(2+) signals from backpropagating action potentials (bAPs). The rise time of the event signal is fast at all ages and is comparable to the rise time of the bAP fluorescence signal at the same dendritic location. The decay time is slower in younger animals, primarily because of weaker Ca(2+) extrusion mechanisms at that age. Diffusion away from a brief localized source is the major determinant of decay at all ages. A simple computational model closely simulates these events with extrusion rate the only age dependent variable. PMID:22951184

  17. The mammalian neocortical pyramidal cell: a new theory on prenatal development

    Miguel eMarín-Padilla

    2014-01-01

    Full Text Available Mammals’ new cerebral cortex (neocortex and the new type of pyramidal neuron are mammalian innovations that have evolved for operating their increasing motor capabilities using essentially analogous anatomical and neural makeups. The human neocortex starts to develop in the 6-week-old embryo with the establishment of a primordial cortical organization that resembles the primitive cortices of amphibian and reptiles that operated his early motor activities. From the 8th to the 15th week of age, the new pyramidal neurons, of ependymal origin, are progressively incorporated within this primordial cortex forming a cellular plate that divide its components into those above it (neocortex first lamina and those below it (neocortex subplate elements. From the 16th week of age to birth and postnatally, the new pyramidal neurons continue to elongate functionally their apical dendrite by adding synaptic membrane to incorporate the needed sensory information for operating the animal muscular activities. The new pyramidal neuron’ distinguishing feature is the capacity of elongating anatomically and functionally its apical dendrite (its main receptive surface without losing its original attachment to first lamina or the location of its soma retaining its essential nature. The number of pyramidal cell functional strata established in the motor cortex increases and reflects each mammalian species motor capabilities: the hedgehog needs 2 pyramidal cell functional strata to carry out all its motor activities, the mouse three, cat four, primates 5 and humans 6. The presence of six pyramidal cell functional strata distinguish the human motor cortex from that of others primates. Homo sapiens represent a new evolutionary stage that have transformed his primate brain for operating his unique motor capabilities, such as speaking, writing, painting, sculpturing including thinking as a premotor activity.

  18. Size effect in contact compression of nano- and microscale pyramid structures

    An electrochemical etching approach was developed to fabricate self-similar nano- and microscale pyramid structures on single-crystal gold (1 0 0) surfaces. Using their unique self-similar characteristics, pyramids of (1 1 4) facets were compressed to study the length scale effects in the contact pressure and plastic deformation. At first, many pyramids were compressed simultaneously with a flat mica sheet to measure the ridge angle changes of the deformed pyramids with respect to the sizes of the flattened area. The ridge angle changes were scattered between approximately 2o and 13o for compression displacements of 50-350 nm, in contrast to the perfect plasticity prediction of -4.7o. Then, individual pyramids isolated with a focused ion beam were compressed with a flat tip nanoindenter for displacements of approximately 10-100 nm to obtain the relationship between the contact pressure and the compression depth. The plastic deformation-adjusted contact pressure evaluated by taking into account the initial 6-14 nm roundness offset of the pyramids is characterized by an initial increase up to approximately 2.5 GPa for a shallow compression depth within 10 nm followed by a gradual decay to approximately 450 MPa at a compression depth of 100 nm. This pressure seems to be still decaying towards an asymptotic value predicted by a continuum limit analysis. Given the size and self-similar nature of the pyramids, various mechanisms could possibly contribute to the observed scale dependence. The current study provides valuable experimental evidence for size-dependent material behavior at small length scales

  19. Back-propagation of physiological action potential output in dendrites of slender-tufted L5A pyramidal neurons

    Grewe, Benjamin F.; Audrey Bonnan; Andreas Frick

    2010-01-01

    Pyramidal neurons of layer 5A are a major neocortical output type and clearly distinguished from layer 5B pyramidal neurons with respect to morphology, in vivo firing patterns, and connectivity; yet knowledge of their dendritic properties is scant. We used a combination of whole-cell recordings and Ca2+ imaging techniques in vitro to explore the specific dendritic signalling role of physiological action potential patterns recorded in vivo in layer 5A pyramidal neurons of the whisker-related &...

  20. Evaluation of the pyramidal tract in patients with brain tumor in terms of diffusion anisotropy, apparent diffusion coefficient and eigenvalues

    Diffusion anisotropy index, diffusion trace and eigenvalues of the pyramidal tracts were measured in 19 patients with supratentorial brain tumor using diffusion tensor MR imaging. These indices reflected condition of pyramidal tract, being compressed and/or being T2-high. Estimation of eigenvalues, in addition to diffusion anisotropy and the trace, should provide more detailed information about the pyramidal tract in brain tumor cases. (author)

  1. What's a Pregnant Woman to Eat? A Review of Current USDA Dietary Guidelines and MyPyramid

    Fowles, Eileen R.

    2006-01-01

    The purpose of this article is to clarify the nutritional recommendations for pregnant women in light of the new Food Guide Pyramid, known as “MyPyramid,” along with the Dietary Guidelines for Americans 2005 and recommendations by the Institute of Medicine. The differences between the Food Guide Pyramid (introduced in 1992) and the more recent, color-coded MyPyramid (introduced in 2005) are discussed. A list of nutritional recommendations for pregnant women is presented, which may serve as a ...

  2. Revisiting pyramid compression to quantify flexoelectricity: A three-dimensional simulation study

    Abdollahi, Amir; Millán, Daniel; Peco, Christian; Arroyo, Marino; Arias, Irene

    2015-03-01

    Flexoelectricity is a universal property of all dielectrics by which they generate a voltage in response to an inhomogeneous deformation. One of the controversial issues in this field concerns the magnitude of flexoelectric coefficients measured experimentally, which greatly exceed theoretical estimates. Furthermore, there is a broad scatter amongst experimental measurements. The truncated pyramid compression method is one of the common setups to quantify flexoelectricity, the interpretation of which relies on simplified analytical equations to estimate strain gradients. However, the deformation fields in three-dimensional pyramid configurations are highly complex, particularly around its edges. In the present work, using three-dimensional self-consistent simulations of flexoelectricity, we show that the simplified analytical estimations of strain gradients in compressed pyramids significantly overestimate flexoelectric coefficients, thus providing a possible explanation to reconcile different estimates. In fact, the interpretation of pyramid compression experiments is highly nontrivial. We systematically characterize the magnitude of this overestimation, of over one order of magnitude, as a function of the truncated pyramid configuration. These results are important to properly characterize flexoelectricity, and provide design guidelines for effective electromechanical transducers exploiting flexoelectricity.

  3. Gamma spectrometry analysis of soil and rock samples from the hypothetical complex of the Bosnian pyramids

    In Europe, officially until now, there have not existed pyramids built by ancient civilisations. In central Bosnia and Herzegovina, about 30 kilometres north from Sarajevo, there are suspected stone pyramids of monumental proportions. The hypothesis that Visocica Hill, having a noticeable pyramidal shape and rising over the town of Visoko, hides inside itself a step pyramid was developed by Semir Osmanagic, a brilliant Bosnian explorer and expert in pyramidal structures which he studied at locations around the world. Aiming to confirm this hypothesis, intensive researches were carried out at the sites of Visoko town and its vicinity in 2005 and 2006, through combination of classic geo-archeological methods and high-technology methods (satellite imagery, thermal analysis, georadar, seismic and electromagnetic methods, 3D topographic and geodetic high-resolution maps). Tens of world experts (including the leading Egyptian archeologists) undoubtedly confirmed that central B and H hides extraordinary important archeological site on a world scale. The idea of the researches shown in this paper is to determine with nuclear measuring methods whether the regular geometric stone blocks, some weighting over 25 tons, which were excavated at this site, originated from natural geologic processes or these are phenomena made by human hands. For that purpose samples were taken for analysis from stone blocks, soil, as well as from soil and stone structures in the network of underground corridors. In this paper we presented results of gamma spectrometry analysis of these samples, obtained with HPGe detectors. (author)

  4. Characterization of synthetic reconstructors for the pyramid wavefront sensor unit of LBTI

    Bailey, V.; Vaitheeswaran, V.; Codona, J.; Hinz, P.; Durney, O.; Esposito, S.; Pinna, E.; Puglisi, A.

    2010-07-01

    We present progress and results for the pyramid wavefront sensor unit on the Large Binocular Telescope's Interferometer (LBTI). The system is a clone of the pyramid sensor unit developed at Arcetri Observatory for the LUCIFER instrument. We discuss the performance of simulated reconstructors during preliminary on-sky testing at the MMT. These reconstructors were generated with the code AOSim2, a customizable end-to-end simulator of a telescope and its AO system. We used the 3-5μm imager Clio to take fast exposures at 3.8μm, from which we calculated Strehl Ratios (SR) for each pyramid configuration and for the Shack-Hartmann (SH) system currently installed. We obtained instantaneous SR as high as 60% for the pyramid as compared to 65% mean for the SH.We identify improvements which will increase the SR in future implementations. These tests demonstrate the feasibility of commissioning a pyramid wavefront sensor on LBTI using a synthetic reconstructor.

  5. The food pyramid adapted to physically active adolescents as a nutrition education tool

    Camila Brandão Gonçalves

    2014-03-01

    Full Text Available This study aimed to assess the understanding of the Food Pyramid Adapted to Physically Active Adolescents as an educational tool to improve nutrition knowledge. Adolescents engaged in sport training responded to a nutrition knowledge questionnaire before and after the intervention. The pyramid intervention group received the printed educational material, and the broad intervention group received the printed material followed by a lecture. As a result, mean initial nutrition knowledge was average (59.9 ± 18 points, increasing (p<0.001 after the intervention (69.1 ± 20 points without significant difference between interventions. In conclusion, adolescents' nutrition knowledge improved, even with the use of the Food Pyramid alone, indicating its use to promote nutritional knowledge.

  6. PYRAMIR: Calibration and operation of a pyramid near-infrared wavefront sensor

    Peter, D; Dorner, B; Henning, T; Hippler, S; Aceituno, J

    2008-01-01

    The concept of pyramid wavefront sensors (PWFS) has been around about a decade by now. However, there is still a great lack of characterizing measurements that allow the best operation of such a system under real life conditions at an astronomical telescope. In this article we, therefore, investigate the behavior and robustness of the pyramid infrared wavefront sensor PYRAMIR mounted at the 3.5 m telescope at the Calar Alto Observatory under the influence of different error sources both intrinsic to the sensor, and arising in the preceding optical system. The intrinsic errors include diffraction effects on the pyramid edges and detector read out noise. The external imperfections consist of a Gaussian profile in the intensity distribution in the pupil plane during calibration, the effect of an optically resolved reference source, and noncommon-path aberrations. We investigated the effect of three differently sized reference sources on the calibration of the PWFS. For the noncommon-path aberrations the quality ...

  7. Hot press molding process for pyramid-type glass optical multiplexer

    Ko, Myeong-Jin; Park, Soon-Sub

    2014-12-01

    By developing a pyramid-shaped reflector, we were able to remove the optical filter that causes the decline in light efficiency in existing systems. A pyramid-type glass optical multiplexer (MUX) can be designed for beam coupling efficiency >60% in a combined module. The module was designed and optimized using CODE V, which utilizes nonlinear curve fitting numerical analysis. Based on optical design data, aspheric grinding paths were developed using ULG APS software. Tungsten carbide optical MUX mold cores were fabricated with an ultraprecision grinding machining device [ULG-100C(H3)] and optimum grinding machining of optical surface roughness (99.985%. A pyramid-type glass optical MUX molding technique was developed using an optical mold design, ultraprecision grinding machining technology, and a hot press molding system.

  8. Lower Cambrian yolk-pyramid embryos from Southern Shaanxi,China

    CHEN Junyuan; Andreas BRAUN; Dieter WALOSZEK; PENG Qingqing; Andreas MAAS

    2004-01-01

    Phosphatized globules with radially arranged pillars were recently recorded from the Lower Cambrian phosphate deposit, Ningqiang, Shaanxi by Yue and Bengtson. These authors interpreted the globules as blastula stage of embryos and the pillars as blastomeres. On the basis of new additional material, we reinterpret these structures as yolk-pyramid stages of possible arthropod eggs. The 20 embryos under present study range from 380 μm to 600 μm in diameter and contain about 120 pyramids. Some embryos having a higher number of pyramids are tentatively interpreted as slightly later developmental stages of the same animal. These 543-million-year-old embryos may push back the evolutionary history of the arthropods to a deeper time and also suggest that one important pattern of arthropod development was already present at the beginning of the Cambrian.

  9. Dynamic chest image analysis: model-based pulmonary perfusion analysis with pyramid images

    Liang, Jianming; Haapanen, Arto; Jaervi, Timo; Kiuru, Aaro J.; Kormano, Martti; Svedstrom, Erkki; Virkki, Raimo

    1998-07-01

    The aim of the study 'Dynamic Chest Image Analysis' is to develop computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected at different phases of the respiratory/cardiac cycles in a short period of time. We have proposed a framework for ventilation study with an explicit ventilation model based on pyramid images. In this paper, we extend the framework to pulmonary perfusion study. A perfusion model and the truncated pyramid are introduced. The perfusion model aims at extracting accurate, geographic perfusion parameters, and the truncated pyramid helps in understanding perfusion at multiple resolutions and speeding up the convergence process in optimization. Three cases are included to illustrate the experimental results.

  10. Growth of large laser deposited Cu-pyramides on Si at raised temperatures

    Seyffarth, Susanne; Krebs, Hans-Ulrich [Institut fuer Materialphysik, Universitaet Goettingen (Germany)

    2008-07-01

    Thin Cu films were prepared on Si(111) and Si(100) substrates using pulsed laser deposition (PLD) in ultra high vacuum. Especially the effect of elevated substrate temperatures on the growth of Cu on Si was investigated. While for low substrate temperatures closed films with small grains are observed, for temperatures above 200 C epitaxial growth of three dimensional pyramides with edge lengths of a few micrometers is observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Depending on the orientation of the substrate the base area of the islands is a triangle for Si(111) and a square for Si(100). In both cases the height of the pyramides is up to 500 nm. The epitaxial relationships with the Si substrates, the dependences of the pyramidal sizes on the number of laser pulses, the stability of the structures and possibilities for an ordering of the islands are discussed.

  11. Epitaxial growth of micrometer-sized Cu-pyramides on silicon

    Seyffarth, Susanne; Krebs, Hans-Ulrich [Institut fuer Materialphysik, Universitaet Goettingen (Germany)

    2009-07-01

    Studying the morphology of thin metallic films is very important regarding the properties of these films. Therefore thin Cu films on Si(111) and Si(100) substrates were prepared using pulsed laser deposition (PLD) in ultra high vacuum. At elevated substrate temperatures above 200 C epitaxial growth of three dimensional pyramides with edge lengths of about five micrometers and heights up to 500 nanometers is observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The base area of these islands is a triangle for Si(111) and a square for Si(100) depending on the orientation of the substrate. Epitaxial relationships with the Si substrates were studied using X-ray diffraction analysis (XRD). Furthermore periodic alignments of the pyramidal islands was achieved. The shape of the pyramidal islands was influenced by alloying Ni during deposition process. Additionally the decomposition of the Cu-islands was examined.

  12. Fabrication and Photoluminescence Properties of Hexagonal Micro-pyramids ZnO Powders by Combustion Synthesis

    CHEN Ai; ZHANG Ying; MENG Fancheng; WANG Hairong; LI Zesong; SHEN Yingping

    2011-01-01

    The ZnO powder with hexagonal-pyramids structure was prepared by the low-temperature combustion process.Ammonium acetate was used as the fuels,whereas zinc nitrate acted as the oxidant.The effect of different ration between fuel and oxidant on the morphology and photoluminescence(PL)characteristic was studied.The formation of hexagonal-pyramids structure was discussed.The optimum preparing parameter for fine morphology is that the ratio of zinc nitrate and ammonium acetate is 1:5,and ignition temperature is 500 ℃.The PL measurement indicates all samples have the strong blue and yellow emission peak.The changes of surface energy of the polar surfaces result in the formation of micro-pyramids structure.

  13. Sparse aperture differential piston measurements using the pyramid wave-front sensor

    Arcidiacono, Carmelo; Yan, Zhaojun; Zheng, Lixin; Agapito, Guido; Wang, Chaoyan; Zhu, Nenghong; Zhu, Liyun; Cai, Jianqing; Tang, Zhenghong

    2016-01-01

    In this paper we report on the laboratory experiment we settled in the Shanghai Astronomical Observatory (SHAO) to investigate the pyramid wavefront sensor (WFS) ability to measure the differential piston on a sparse aperture. The ultimate goal is to verify the ability of the pyramid WFS work in closed loop to perform the phasing of the primary mirrors of a sparse Fizeau imaging telescope. In the experiment we installed on the optical bench we performed various test checking the ability to flat the wave-front using a deformable mirror and to measure the signal of the differential piston on a two pupils setup. These steps represent the background from which we start to perform full closed loop operation on multiple apertures. These steps were also useful to characterize the achromatic double pyramids (double prisms) manufactured in the SHAO optical workshop.

  14. Effect of Pyramidal Dome Geometry on the Acoustical Characteristics in A Mosque

    Dg. H. Kassim

    2014-12-01

    Full Text Available As an important symbol in Islam, a mosque is built with architectural grandeur. Among the characteristics is its high ceiling and it is usually constructed with a typical spherical dome shape. Some mosques, however, are influenced by the local culture and the dome can be of a different shape, such as pyramidal, as found in mosques in Malacca, Malaysia. This paper presents an assessment of the internal acoustical characteristics of a mosque having a pyramidal dome. The study is conducted by means of computer simulation using CATT indoor acoustic software. Reverberation time and clarity are taken to evaluate the intelligibility of speech. The effect of the angle and height of the dome on the acoustical parameters is discussed. It is found that a pyramidal dome with a steeper angle contributes to poor acoustic clarity.

  15. Existence and uniqueness of a class of double pyramidal central configurations in six-body problems

    LIU Xuefei

    2004-01-01

    Under the necessary conditions for a double pyramidal central configuration with a diamond base to exist in the real number space, the existence and uniqueness of such configurations were studied by employing combinedly the algebraic method and numerical calculation. It is found that there exists a planar curl triangle region G in a square Q such that any point in G and given by the ratio of the two diagonal lengths of the diamond base and the ratio of one diagonal length of the base to the height of the double pyramid configuration determines a unique double pyramid central configuration, while all points in Q-G have no referance to any central configuration.

  16. Fractal Analysis of Laplacian Pyramidal Filters Applied to Segmentation of Soil Images

    J. de Castro

    2014-01-01

    Full Text Available The laplacian pyramid is a well-known technique for image processing in which local operators of many scales, but identical shape, serve as the basis functions. The required properties to the pyramidal filter produce a family of filters, which is unipara metrical in the case of the classical problem, when the length of the filter is 5. We pay attention to gaussian and fractal behaviour of these basis functions (or filters, and we determine the gaussian and fractal ranges in the case of single parameter a. These fractal filters loose less energy in every step of the laplacian pyramid, and we apply this property to get threshold values for segmenting soil images, and then evaluate their porosity. Also, we evaluate our results by comparing them with the Otsu algorithm threshold values, and conclude that our algorithm produce reliable test results.

  17. Fractal Analysis of Laplacian Pyramidal Filters Applied to Segmentation of Soil Images

    de Castro, J.; Méndez, A.; Tarquis, A. M.

    2014-01-01

    The laplacian pyramid is a well-known technique for image processing in which local operators of many scales, but identical shape, serve as the basis functions. The required properties to the pyramidal filter produce a family of filters, which is unipara metrical in the case of the classical problem, when the length of the filter is 5. We pay attention to gaussian and fractal behaviour of these basis functions (or filters), and we determine the gaussian and fractal ranges in the case of single parameter a. These fractal filters loose less energy in every step of the laplacian pyramid, and we apply this property to get threshold values for segmenting soil images, and then evaluate their porosity. Also, we evaluate our results by comparing them with the Otsu algorithm threshold values, and conclude that our algorithm produce reliable test results. PMID:25114957

  18. A cognitive approach to the topography of the 12th dynasty pyramids

    Magli, Giulio

    2010-01-01

    The topography of the royal pyramids of the 12th dynasty is investigated in its historical and chronological context, in order to highlight connections between the architectural choices, the religious ideas and the traditions inspiring the reign of the corresponding pharaohs. A close, explicit connection with the double building projects carried out more than six centuries before by Snefru at Dahshur and at Meidum-Seila comes out. This connection involved geometry, perspective and astronomical alignments in the progressive planning of the pyramidal complexes. In such a context, the architectural choices of the last great king of the dynasty, Amenemhet III - who built two pyramids, one at Dahshur and the other at Hawara - appear to be due mostly to symbolic, as opposed to practical, reasons.

  19. Broadband Absorption Enhancement in Thin Film Solar Cells Using Asymmetric Double-Sided Pyramid Gratings

    Alshal, Mohamed A.; Allam, Nageh K.

    2016-07-01

    A design for a highly efficient modified grating crystalline silicon (c-Si) thin film solar cell is demonstrated and analyzed using the two-dimensional (2-D) finite element method. The suggested grating has a double-sided pyramidal structure. The incorporation of the modified grating in a c-Si thin film solar cell offers a promising route to harvest light into the few micrometers active layer. Furthermore, a layer of silicon nitride is used as an antireflection coating (ARC). Additionally, the light trapping through the suggested design is significantly enhanced by the asymmetry of the top and bottom pyramids. The effects of the thickness of the active layer and facet angle of the pyramid on the spectral absorption, ultimate efficiency (η), and short-circuit current density (J sc) are investigated. The numerical results showed 87.9% efficiency improvement over the conventional thin film c-Si solar cell counterpart without gratings.

  20. Housing in Pyramid Counteracts Neuroendocrine and Oxidative Stress Caused by Chronic Restraint in Rats

    M. Surekha Bhat

    2007-01-01

    Full Text Available The space within the great pyramid and its smaller replicas is believed to have an antistress effect. Research has shown that the energy field within the pyramid can protect the hippocampal neurons of mice from stress-induced atrophy and also reduce neuroendocrine stress, oxidative stress and increase antioxidant defence in rats. In this study, we have, for the first time, attempted to study the antistress effects of pyramid exposure on the status of cortisol level, oxidative damage and antioxidant status in rats during chronic restraint stress. Adult female Wistar rats were divided into four groups as follows: normal controls (NC housed in home cage and left in the laboratory; restrained rats (with three subgroups subject to chronic restraint stress by placing in a wire mesh restrainer for 6 h per day for 14 days, the restrained controls (RC having their restrainers kept in the laboratory; restrained pyramid rats (RP being kept in the pyramid; and restrained square box rats (RS in the square box during the period of restraint stress everyday. Erythrocyte malondialdehyde (MDA and plasma cortisol levels were significantly increased and erythrocyte-reduced glutathione (GSH levels, erythrocyte glutathione peroxidase (GSH-Px and superoxide dismutase (SOD activities were significantly decreased in RC and RS rats as compared to NC. However, these parameters were maintained to near normal levels in RP rats which showed significantly decreased erythrocyte MDA and plasma cortisol and significantly increased erythrocyte GSH levels, erythrocyte GSH-Px and SOD activities when compared with RS rats. The results showed that housing in pyramid counteracts neuroendocrine and oxidative stress caused by chronic restraint in rats.

  1. A pyramid-based approach to visual exploration of a large volume of vehicle trajectory data

    Jing SUN; Xiang LI

    2012-01-01

    Advances in positioning and wireless communicating technologies make it possible to collect large volumes of trajectory data of moving vehicles in a fast and convenient fashion.These data can be applied to traffic studies.Behind this application,a methodological issue that still requires particular attention is the way these data should be spatially visualized.Trajectory data physically consists of a large number of positioning points.With the dramatic increase of data volume,it becomes a challenge to display and explore these data.Existing commercial software often employs vector-based indexing structures to facilitate the display of a large volume of points,but their performance downgrades quickly when the number of points is very large,for example,tens of millions.In this paper,a pyramid-based approach is proposed.A pyramid method initially is invented to facilitate the display of raster images through the tradeoff between storage space and display time.A pyramid is a set of images at different levels with different resolutions.In this paper,we convert vector-based point data into raster data,and build a gridbased indexing structure in a 2D plane.Then,an image pyramid is built.Moreover,at the same level of a pyramid,image is segmented into mosaics with respect to the requirements of data storage and management.Algorithms or procedures on grid-based indexing structure,image pyramid,image segmentation,and visualization operations are given in this paper.A case study with taxi trajectory data in Shanghai is conducted.Results demonstrate that the proposed method outperforms the existing commercial software.

  2. PARTICLE SWARM OPTIMIZATION BASED ON PYRAMID MODEL FOR SATELLITE MODULE LAYOUT

    Zhang Bao; Teng Hongfei

    2005-01-01

    To improve the global search ability of particle swarm optimization (PSO), a multi-population PSO based on pyramid model (PPSO) is presented. Then, it is applied to solve the layout optimization problems against the background of an international commercial communication satellite (INTELSAT-Ⅲ) module. Three improvements are developed, including multi-population search based on pyramid model, adaptive collision avoidance among particles, and mutation of degraded particles. In the numerical examples of the layout design of this simplified satellite module, the performance of PPSO is compared to global version PSO and local version PSO (ring and Neumann PSO). The results show that PPSO has higher computational accuracy, efficiency and success ratio.

  3. Mechanical Response of All-composite Pyramidal Lattice Truss Core Sandwich Structures

    Ming Li; Linzhi Wu; Li Ma; Bing Wang; Zhengxi Guan

    2011-01-01

    The mechanical performance of an all-composite pyramidal lattice truss core sandwich structure was investigated both theoretically and experimentally. Sandwich structures were fabricated with a hot compression molding method using carbon fiber reinforced composite T700/3234. The out-of-plane compression and shear tests were conducted. Experimental results showed that the all-composite pyramidal lattice truss core sandwich structures were more weight efficient than other metallic lattice truss core sandwich structures. Failure modes revealed that node rupture dominated the mechanical behavior of sandwich structures.

  4. Novel electrodeless-dielectrophoresis device for nanoparticle trapping using three-dimensional inverted-pyramid arrays

    Chiou, Chi-Han; Chien-Lung Lin, Liang-Ju, Jr.; Kuo, Ju-Nan

    2016-05-01

    A novel electrodeless-dielectrophoresis (EDEP) device incorporating three-dimensional (3D) inverted-pyramid arrays is proposed for the trapping and separation of nanoparticles. The electrokinetic phenomena in the proposed device are investigated both numerically and experimentally. The results reveal that the pyramid structures induce a 3D squeezed electric field, which allows particle trapping with a lower driving voltage than that required in traditional two-dimensional (2D) EDEP devices. Overall, the proposed EDEP device provides a mass-producible solution for nanoparticle-trapping applications and overcomes the Poisson statistical limit inherent in 2D nanogap-based EDEP devices with smaller (pL) sample volumes.

  5. Electronic microscopy and EDX characterization of teotihuacan prehispanic mortar from the cave under the sun pyramid

    A cave (102 m long) under the structure of the Sun pyramid of the prehispanic Teotihuacan City indicates the importance of the pyramid. Studies of the cave mortar samples using energy dispersive X-ray (EDX) fluorescence, scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed no difference in the chemical elemental composition. The elements can be distributed in three groups: major, minor and trace elements. The minerals identified were compatible with the origins of the cave and with the magnetic pattern

  6. Innovation Intensity and Adoption at the Base of the Pyramid Market: A Study of Household Appliances

    Vitor Koki da Costa Nogami

    2015-08-01

    Full Text Available The paper analyzes the innovation intensity and adoption characteristics at the base of the pyramid market. The innovation intensity is configured as radical and incremental, while the innovation adoption is configured as early and tardy. As an empirical approach it was conducted a study type survey. Data analysis is based on non-parametric statistics. The results indicate that the base of the pyramid consumers is characterized by adopting incremental innovations tardily, as pointed out by the literature. Furthermore, it was also observed that women have greater decision-making power in the families of this segment.

  7. The influence of surface structures on sputtering: angular distributions from pyramid-covered single crystal copper

    The angular distribution of 40 keV argon sputtered copper has been measured. Comparison is made of the distributions from a flat surface (featureless at 10.000X) and from a pyramid-covered surface. Three different orientations of the single crystal have been used to bring the low index directions and as well as the into the plane of the collector foil. Enhanced ejections from the low index directions are seen to decrease in the order , low index directions not in but near the collector plane can also influence the angular distributions. Generally, the total yield is higher from the pyramid-covered surface than from the flat. (Auth.)

  8. Electronic microscopy and EDX characterization of teotihuacan prehispanic mortar from the cave under the sun pyramid

    Martinez, T. [Faculty of Chemistry, National University of Mexico, Building D, CU (O4510) Mexico, D.F. (Mexico)]. E-mail: tmc@servidor.unam.mx; Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural. Xicontencatl y General Anaya s/n. (04120) Mexico, D.F. (Mexico); Mendoza, D. [National Institute of Nuclear Research.. Carr. Mexico-Toluca Km 36.5 (52045), Salazar, Ocoyoacac, Edo. de Mexico (Mexico); Juarez, F. [Institute of Geophysics, National University of Mexico, Circuito Institutos, CU (04510) Mexico, D.F. (Mexico); Cabrera, L. [Faculty of Chemistry, National University of Mexico, Building D, CU (O4510) Mexico, D.F. (Mexico)

    2005-12-01

    A cave (102 m long) under the structure of the Sun pyramid of the prehispanic Teotihuacan City indicates the importance of the pyramid. Studies of the cave mortar samples using energy dispersive X-ray (EDX) fluorescence, scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed no difference in the chemical elemental composition. The elements can be distributed in three groups: major, minor and trace elements. The minerals identified were compatible with the origins of the cave and with the magnetic pattern.

  9. Electronic microscopy and EDX characterization of Teotihuacan prehispanic mortar from the cave under the Sun Pyramid.

    Martinez, T; Martinez, G; Mendoza, D; Juarez, F; Cabrera, L

    2005-01-01

    A cave (102 m long) under the structure of the Sun pyramid of the prehispanic Teotihuacan City indicates the importance of the pyramid. Studies of the cave mortar samples using energy dispersive X-ray (EDX) fluorescence, scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed no difference in the chemical elemental composition. The elements can be distributed in three groups: major, minor and trace elements. The minerals identified were compatible with the origins of the cave and with the magnetic pattern. PMID:15996472

  10. Pyramid Wavefront Sensor at the William Herschel Telescope: Towards Extremely Large Telescopes

    Esposito, S.; Pinna, E.; Tozzi, A.; Puglisi, A.; Stefanini, P.

    2005-12-01

    The Arcetri adaptive optics group showed in 2001, using numerical simulation, that the pyramid WFS is able to do phasing and alignment of the mirror segments at the same time. In the period 2000-2004 the adaptive optics group developed this concept, and have built a lab prototype of the pyramid co-phasing sensor. A unique opportunity to calibrate and test our prototype in the lab and on the sky has been provided by the William Herschel Telescope and its adaptive optics system NAOMI.

  11. Mediation Analysis

    David P. MacKinnon; Fairchild, Amanda J.; Fritz, Matthew S.

    2007-01-01

    Mediating variables are prominent in psychological theory and research. A mediating variable transmits the effect of an independent variable on a dependent variable. Differences between mediating variables and confounders, moderators, and covariates are outlined. Statistical methods to assess mediation and modern comprehensive approaches are described. Future directions for mediation analysis are discussed.

  12. Coaching Early Educators to Implement Effective Practices: Using the Pyramid Model to Promote Social-Emotional Development

    Fox, Lise; Hemmeter, Mary Louise

    2011-01-01

    The Pyramid Model is a conceptual framework for organizing practices for promoting young children's social-emotional development and preventing and addressing challenging behavior. The authors describe a coaching approach that is focused on supporting early educators' implementation of the Pyramid Model. The authors provide a description of the…

  13. Experience-dependent plasticity of dendritic spines of layer 2/3 pyramidal neurons in the mouse cortex.

    Ma, Lei; Qiao, Qian; Tsai, Jin-Wu; Yang, Guang; Li, Wei; Gan, Wen-Biao

    2016-03-01

    Previous studies have shown that sensory and motor experiences play an important role in the remodeling of dendritic spines of layer 5 (L5) pyramidal neurons in the cortex. In this study, we examined the effects of sensory deprivation and motor learning on dendritic spine remodeling of layer 2/3 (L2/3) pyramidal neurons in the barrel and motor cortices. Similar to L5 pyramidal neurons, spines on apical dendrites of L2/3 pyramidal neurons are plastic during development and largely stable in adulthood. Sensory deprivation via whisker trimming reduces the elimination rate of existing spines without significant effect on the rate of spine formation in the developing barrel cortex. Furthermore, we show that motor training increases the formation and elimination of dendritic spines in the primary motor cortex. Unlike L5 pyramidal neurons, however, there is no significant difference in the rate of spine formation between sibling dendritic branches of L2/3 pyramidal neurons. Our studies indicate that sensory and motor learning experiences have important impact on dendritic spine remodeling in L2/3 pyramidal neurons. They also suggest that the rules governing experience-dependent spine remodeling are largely similar, but not identical, between L2/3 and L5 pyramidal neurons. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 277-286, 2016. PMID:26033635

  14. The self-assemble GaN:Mg inverted hexagonal pyramids formatted by photoelectrochemical wet-etching process

    Small sized self-assembled inverted hexagonal pyramids consisting of GaN:Mg and InGaN/GaN multi-quantum-well (MQW) structures were formed using photoelectrochemical wet etching. Lateral etching, bottom-up etching, and anisotropic etching are the formation mechanism of the pyramids during the etching process sequentially. The dimension of these inverted hexagonal pyramids was measured as 245 nm in width and 184 nm in height, and the angle between the top GaN:Mg surface and the pyramid sidewall was calculated at about 56.3o. Due to the strain relief in the nano-disk MQW structure we induced an emission peak of photoluminescence at the tip of the inverted hexagonal pyramid which had a strong blue shift of 244 meV at 100 K

  15. Effectively Improved Field Emission Properties of Multiwalled Carbon Nanotubes/Graphenes Composite Field Emitter by Covering on the Si Pyramidal Structure

    Chen, Leifeng; Yu, Hua; Zhong, Jiasong;

    2015-01-01

    The composite nanostructure emitter of multiwalled carbon nanotubes and graphenes was deposited on pyramidal silicon substrate by the simple larger scale electrophoretic deposition process. The field emission (FE) properties of the composite/pyramidal Si device were greatly improved compared with...... that of the composite/plain Si. The low turn-ON electric field, the low threshold electric field, and the larger enhancement factor were obtained using the pyramidal structure. The better FE performances of the composite/pyramidal Si were a combined effect of the field enhancement from the composite...... emitter and the pyramidal Si structure. The numerical simulation of the electric field distribution on composite/pyramidal cathode was used to illuminate the improved FE properties by using the pyramidal substrate. These studies indicate that constructing composite/pyramidal structure is one of the...

  16. Estrogen induces rapid decrease in dendritic thorns of CA3 pyramidal neurons in adult male rat hippocampus

    Modulation of hippocampal synaptic plasticity by estrogen has been attracting much attention. Thorns of thorny excrescences of CA3 hippocampal neurons are post-synaptic regions whose presynaptic partners are mossy fiber terminals. Here we demonstrated the rapid effect of estradiol on the density of thorns of thorny excrescences, by imaging Lucifer Yellow-injected CA3 neurons in adult male rat hippocampal slices. The application of 1 nM estradiol induced rapid decrease in the density of thorns on pyramidal neurons within 2 h. The estradiol-mediated decrease in the density of thorns was blocked by CNQX (AMPA receptor antagonist) and PD98059 (MAP kinase inhibitor), but not by MK-801 (NMDA receptor antagonist). ERα agonist PPT induced the same suppressive effect as that induced by estradiol on the density of thorns, but ERβ agonist DPN did not affect the density of thorns. Note that a 1 nM estradiol treatment did not affect the density of spines in the stratum radiatum and stratum oriens. A search for synaptic ERα was performed using purified RC-19 antibody. The localization of ERα (67 kDa) in the CA3 mossy fiber terminals and thorns was demonstrated using immunogold electron microscopy. These results imply that estradiol drives the signaling pathway including ERα and MAP kinase

  17. Large pyramid shaped single crystals of BiFeO{sub 3} by solvothermal synthesis method

    Sornadurai, D.; Ravindran, T. R.; Paul, V. Thomas; Sastry, V. Sankara [Condensed Matter Physics Division, Materials Science Group, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Condensed Matter Physics Division, Materials Science Group (India)

    2012-06-05

    Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO{sub 3}. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

  18. Large pyramid shaped single crystals of BiFeO3 by solvothermal synthesis method

    Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO3. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

  19. Factors Affecting Energy Barriers for Pyramidal Inversion in Amines and Phosphines: A Computational Chemistry Lab Exercise

    Montgomery, Craig D.

    2013-01-01

    An undergraduate exercise in computational chemistry that investigates the energy barrier for pyramidal inversion of amines and phosphines is presented. Semiempirical calculations (PM3) of the ground-state and transition-state energies for NR[superscript 1]R[superscript 2]R[superscript 3] and PR[superscript 1]R[superscript 2]R[superscript 3] allow…

  20. Effects of Distance Coaching on Teachers' Use of Pyramid Model Practices: A Pilot Study

    Artman-Meeker, Kathleen; Hemmeter, Mary Louise; Snyder, Patricia

    2014-01-01

    The purpose of this pilot study was to compare the effects of 2 professional development approaches on teachers' implementation of the "Pyramid" model, a classroom-wide approach for fostering social-emotional development and addressing challenging behavior. The study had 2 goals: (a) to examine the differential effects of workshop…

  1. Near-surface geophysical characterization of Holocene faults conducive to geothermal flow near Pyramid Lake, Nevada

    Dudley, Colton; Dorsey, Alison; Louie, John [UNR; Schwering, Paul; Pullammanappallil, Satish

    2016-08-01

    Colton Dudley, Alison Dorsey, Paul Opdyke, Dustin Naphan, Marlon Ramos, John Louie, Paul Schwering, and Satish Pullammanappallil, 2013, Near-surface geophysical characterization of Holocene faults conducive to geothermal flow near Pyramid Lake, Nevada: presented at Amer. Assoc. Petroleum Geologists, Pacific Section Annual Meeting, Monterey, Calif., April 19-25.

  2. Pyramidal texturing of silicon surface via inorganic-organic hybrid alkaline liquor for heterojunction solar cells

    Wang, Fengyou; Zhang, Xiaodan; Wang, Liguo; Jiang, Yuanjian; Wei, Changchun; Zhao, Ying

    2015-10-01

    We demonstrate a new class of silicon texturing approach based on inorganic (sodium hydroxide, NaOH) and organic (tetramethylammonium hydroxide, TMAH) alkaline liquor etching processes for photovoltaic applications. The first stage of inorganic alkaline etching textures the silicon surface rapidly with large pyramids and reduces the cost. The subsequent organic alkaline second-etching improves the coverage of small pyramids on the silicon surface and strip off the metallic contaminants produced by the first etching step. In addition, it could smoothen the surface of the pyramids to yield good morphology. In this study, the texturing duration of both etching steps was controlled to optimize the optical and electrical properties as well as the surface morphology and passivation characteristics of the silicon substrates. Compared with traditional inorganic NaOH texturing, this hybrid process yields smoother (111) facets of the pyramids, fewer residual Na+ ions on the silicon surface, and a shorter processing period. It also offers the advantage of lower cost compared with the organic texturing method based on the use of only TMAH. We applied this hybrid texturing process to fabricate silicon heterojunction solar cells, which showed a remarkable improvement compared with the cells based on traditional alkaline texturing processes.

  3. The Diffusion of the Learning Pyramid Myths in Academia: An Exploratory Study

    Letrud, Kåre; Hernes, Sigbjørn

    2016-01-01

    This article examines the diffusion and present day status of a family of unsubstantiated learning-retention myths, some of which are referred to as "the learning pyramid". We demonstrate through an extensive search in academic journals and field-specific encyclopaedias that these myths are indeed widely publicised in academia and that…

  4. Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    A. K. Eisses, A. M. Kell, G. Kent, N. W. Driscoll, R. E. Karlin, R. L. Baskin, J. N. Louie, S. Pullammanappallil, 2010, Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada: Abstract T33C-2278 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13-17 Dec.

  5. Installation, operation, and maintenance for the pyramidal optics solar system installed at Yacht Cove, Columbia, SC

    1980-09-01

    Information is presented concerning the installation, operation, and maintenance of the pyramidal Solar System for space heating and domestic hot water. Included are such items as principles of operation, sequence of installation, and procedures for the operation and maintenance of each subsystem making up the solar system. Also included are trouble-shooting charts and maintenance schedules.

  6. Community health advisors' perceptions of the 2005 Dietary Guidelines and MyPyramid

    Abstract Objectives: To describe Community Health Advisors' (CHAs) awareness, knowledge, and perceptions of the 2005 Dietary Guidelines for Americans (2005 DG) and MyPyramid. Methods & Subjects: A 33-item self-administered questionnaire was completed by 106 CHAs residing in Alabama and Mississippi. ...

  7. Differences in etching characteristics of TMAH and KOH on preparing inverted pyramids for silicon solar cells

    Fan, Yujie; Han, Peide; Liang, Peng; Xing, Yupeng; Ye, Zhou; Hu, Shaoxu

    2013-01-01

    In this paper, a series of comparative etching experiments on preparing inverted pyramids of silicon solar cells have been carried out using tetramethyl ammonium hydroxide (TMAH) and potassium hydroxide (KOH) at different etchant concentrations and temperatures on a patterned (1 0 0) Si. These experiment results show that TMAH solution has higher undercut rate and lower (1 0 0) plane etch rate than KOH solution, and the (1 1 1)/(1 0 0) etch rate ratio of TMAH is two to three times that of KOH solution. Additionally, etch rate of SiO2 mask is an order of magnitude lower in TMAH than in KOH. Besides, surface morphology analysis indicates that TMAH etching can obtain much higher quality inverted pyramids of sharp vertex, smooth (1 1 1) sidewall and uncontaminated surface than KOH etching, which makes TMAH etching samples show better antireflection properties. Finally, the minimum reflectivity of TMAH etching sample low as 1.8% is obtained for inverted pyramids covered with SiO2 reflectivity coating. So the study reveals that TMAH is more attractive for the preparation of inverted pyramids than KOH.

  8. The Bottom of the Pyramid: Much ado, but is it enough?

    Crabtree, Andrew

    2008-01-01

    Although Prahalad does not address the issues surrounding multidimensional poverty, many of his cases fit the notion of multidimensional poverty better than they suit income poverty suggesting that we should re-focus BOP from the Bottom of the Pyramid to Multidimensional Poverty solutions....

  9. Wall Crossing of BPS States on the Conifold from Seiberg Duality and Pyramid Partitions

    Chuang, Wu-yen

    2008-01-01

    In this paper we study the relation between pyramid partitions with a general empty room configuration (ERC) and the BPS states of D-branes on the resolved conifold. We find that the generating function for pyramid partitions with a length n ERC is exactly the same as the D6/D2/D0 BPS partition function on the resolved conifold in particular Kaehler chambers. We define a new type of pyramid partition with a finite ERC that counts the BPS degeneracies in certain other chambers. The D6/D2/D0 partition functions in different chambers were obtained by applying the wall crossing formula. On the other hand, the pyramid partitions describe $T^3$ fixed points of the moduli space of a quiver quantum mechanics. This quiver arises after we apply Seiberg dualities to the D6/D2/D0 system on the conifold and choose a particular set of FI parameters. The arrow structure of the dual quiver is confirmed by computation of the Ext group between the sheaves. We show that the superpotential and the stability condition of the dual...

  10. Gap junctions between CA3 pyramidal cells contribute to network synchronization in neonatal hippocampus.

    Molchanova, Svetlana M; Huupponen, Johanna; Lauri, Sari E; Taira, Tomi

    2016-08-01

    Direct electrical coupling between neurons through gap junctions is prominent during development, when synaptic connectivity is scarce, providing the additional intercellular connectivity. However, functional studies of gap junctions are hampered by the unspecificity of pharmacological tools available. Here we have investigated gap-junctional coupling between CA3 pyramidal cells in neonatal hippocampus and its contribution to early network activity. Four different gap junction inhibitors, including the general blocker carbenoxolone, decreased the frequency of network activity bursts in CA3 area of hippocampus of P3-6 rats, suggesting the involvement of electrical connections in the generation of spontaneous network activity. In CA3 pyramidal cells, spikelets evoked by local stimulation of stratum oriens, were inhibited by carbenoxolone, but not by inhibitors of glutamatergic and GABAergic synaptic transmission, signifying the presence of electrical connectivity through axo-axonic gap junctions. Carbenoxolone also decreased the success rate of firing antidromic action potentials in response to stimulation, and changed the pattern of spontaneous action potential firing of CA3 pyramidal cells. Altogether, these data suggest that electrical coupling of CA3 pyramidal cells contribute to the generation of the early network events in neonatal hippocampus by modulating their firing pattern and synchronization. PMID:26926429

  11. Stress-induced remodeling of hippocampal CA3 pyramidal neurons.

    McEwen, Bruce S

    2016-08-15

    The discovery of steroid hormone receptors in brain regions that mediate virtually every aspect of brain function has broadened the definition of 'neuroendocrinology' to include the reciprocal communication between the brain and the body via hormonal and neural pathways. The brain is the central organ of stress and adaptation to stress because it perceives and determines what is threatening, as well as determining the behavioral and physiological responses to the stressor. The adult and developing brain possess remarkable structural and functional plasticity in response to stress, including neurogenesis leading to neuronal replacement, dendritic remodeling, and synapse turnover. Stress causes an imbalance of neural circuitry subserving cognition, decision-making, anxiety and mood that can alter expression of those behaviors and behavioral states. The two Brain Research papers noted in this review played an important role in triggering these advances. This article is part of a Special Issue entitled SI:50th Anniversary Issue. PMID:26740399

  12. XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries

    Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

    2016-08-01

    X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.

  13. V-pit to truncated pyramid transition in AlGaN-based heterostructures

    The formation of three-dimensional truncated pyramids after the deposition of AlN/GaN superlattices onto (0001) AlN/sapphire templates has been analysed by atomic force microscopy as well as transmission electron microscopy. V-pits in AlN layers and the formation of nano-mounds around the v-pit edges are suggested to be responsible for the pyramid formation. Keeping the individual AlN layer thickness at 2.5 nm in the 80xAlN/GaN superlattice, the transformation to the three-dimensional pyramids is observed when the individual GaN layer thickness exceeds 1.5 nm. A subsequent overgrowth of the pyramidal structures by AlGaN results in inhomogeneous Ga distribution in the layers and laterally inhomogeneous strain states. Nevertheless, compared to the growth on planar layers, the overgrowth of the truncated pyramids leads to a slight reduction in dislocation density from 1 · 1010 cm−2 (for GaN thickness of 1 nm in SL) to 7 · 109 cm−2 (for GaN thickness of 2 nm in SL). The non-planar growth front and thus the compositional inhomogeneity in AlGaN vanish gradually with increasing AlGaN thickness. As a result, homogeneous 4 μm thick Al0.5Ga0.5N buffer layers suitable for the fabrication of UV-B LED structures can be obtained. (paper)

  14. Can astronomy enhance UNESCO World Heritage recognition? The paradigm of 4th Dynasty Egyptian pyramids

    Belmonte, Juan Antonio

    2015-08-01

    The pyramids of Egypt, notably those of the 4th Dinasty as Giza, have always be considered an unmistikable part of human world heritage as the only surviving wonders of the Ancient World. Their majesty, technical hability and innovative character have always beeen considered as representative of ancient Egyptian ingenuity. However, past and present fringe theories about the pyramids and astronomy have always polluted the role of our discipline in the design, construction and symbolism of these impressive monuments. This is indeed unfear. Fortunately, things have started to change in the last couple of decades and now astronomy is interpreted as a neccessary tool for the correct interpretation of the astral eschatology present in the 5th and 6th Dynasty Texts of the Pyramids. Although the pyramid complexes of the 4th Dynasty are mute, there is however recent research showing that a strong astral symbolism could be hidden in many aspects of the complex architecture and in the design of these exceptional monuments. This idea comes from several hints obtained not only from planning and construction, but also from epigraphy and the analysis of celestial and local landscapes. Chronology also plays a most relevant role on this. The pyramid complexes of the 4th Dynasty at Meidum, Dahshur, Giza and Abu Rowash -- all of which enjoy UNESCO World Heritage recognition -- willl be scrutinized. As a consequence, we will show how astronomy can certainly enhance the face value of these extraordinary monuments as a definitive proof of the ancient Egyptian quest for Ma'at, i.e. their perennial obsesion for Cosmic Order.

  15. (11)B MAS NMR and First-Principles Study of the [OBO3] Pyramids in Borates.

    Zhou, Bing; Sun, Wei; Zhao, Biao-Chun; Mi, Jin-Xiao; Laskowski, Robert; Terskikh, Victor; Zhang, Xi; Yang, Lingyun; Botis, Sanda M; Sherriff, Barbara L; Pan, Yuanming

    2016-03-01

    Borates are built from the [Bϕ3] planar triangles and the [Bϕ4] tetrahedral groups, where ϕ denotes O or OH. However, the [Bϕ4] groups in some borates are highly distorted to include three normal B-O bonds and one anomalously long B-O bond and, therefore, are best described as the [OBO3] pyramids. Four synthetic borates of the boracite-type structures (Mg3B7O13Br, Cu3B7O13Br, Zn3B7O13Cl, and Mg3B7O13Cl) containing a range of [OBO3] pyramids were investigated by multifield (7.05, 14.1, and 21.1 T) (11)B magic-angle spinning nuclear magnetic resonance (MAS NMR), triple quantum (3Q) MAS NMR experiments, as well as density functional theory calculations. The high-resolution (11)B MAS NMR spectra supported by theoretical predictions show that the [OBO3] pyramids are characterized by isotropic chemical shifts δiso((11)B) from 1.4(1) to 4.9(1) ppm and nuclear quadrupole parameters CQ((11)B) up to 1.3(1) MHz, both significantly different from those of the [BO4] and [BO3] groups in borates. These δiso((11)B) and CQ((11)B) values indicate that the [OBO3] pyramids represent an intermediate state between the [BO4] tetrahedra and [BO3] triangles and demonstrate that the (11)B NMR parameters of four-coordinate boron oxyanions are sensitive to local structural environments. The orientation of the calculated unique electronic field gradient tensor element Vzz of the [OBO3] pyramids is aligned approximately along the direction of the anomalously long B-O bond, corresponding to B-2pz with the lowest electron density. PMID:26914372

  16. A THYROID GLAND SHOWING PYRAMIDAL LOBE WITH LEVATO R GLANDULAE THYROIDEA .

    Sreekanth

    2013-01-01

    Full Text Available ABSTRACT: The Literature is replete with wide range of common and rare variations of thyroid gland. The presence of pyramidal lobe (accessory lo be – a rostral directed stalk that results from the retention and growth of the caudal end of thyroglossal duct and fibrous or fibromuscular levator glandulae thyroidea (LGT ari sing from its apex are commonly occurring variations . A 50 yrs Old Male Cadaver showed leva tor glandulae thyroidea with cranio caudal extension from the body of the hyoid bone to the ap ex of pyramidal lobe which was projecting upwards from the left ¾ th of isthmus without any encroachment on the left lo be of the thyroid gland. In the groove clearly demarcating pyramidal lobe from the left lobe, a glandular branch of anterior branch of left superior thyroid artery w as seen. It entered the pyramidal lobe inferiorly, just above the lower border of the isth mus. Just adjacent to the right lobe a small portion of isthmus with prominent and free upper border and lower border is seen. Due its frequent presence it may not be fascinating to the Anatomists but can definitely challenge the skill o f operating neck surgeons performing thyroidectomies, lobectomies and isthmusectomies an d Otolaryngologists performing tracheostomies ,tracheotomies and laryngotomies. T he wide range of variations in the number, size, extent and consistency of the levator glandul ae thyroidea (LGT and pyramidal lobe necessitate the pre operative ultrasonographic examina tion or scintigraphical images or intense contrast enhancement on CT/MRI scan for total anato mical details enabling relatively a safer surgery.

  17. Pyramidal cell development: postnatal spinogenesis, dendritic growth, axon growth, and electrophysiology.

    Guy eElston

    2014-08-01

    Full Text Available Here we review recent findings related to postnatal spinogenesis, dendritic and axon growth, pruning and electrophysiology of neocortical pyramidal cells in the developing primate brain. Pyramidal cells in sensory, association and executive cortex grow dendrites, spines and axons at different rates, and vary in the degree of pruning. Of particular note is the fact that pyramidal cells in primary visual area (V1 prune more spines than they grow during postnatal development, whereas those in inferotemporal (TEO and TE and granular prefrontal cortex (gPFC; Brodmann’s area 12 grow more than they prune. Moreover, pyramidal cells in TEO, TE and the gPFC continue to grow larger dendritic territories from birth into adulthood, replete with spines, whereas those in V1 become smaller during this time. The developmental profile of intrinsic axons also varies between cortical areas: those in V1, for example, undergo an early proliferation followed by pruning and local consolidation into adulthood, whereas those in area TE tend to establish their territory and consolidate it into adulthood with little pruning. We correlate the anatomical findings with the electrophysiological properties of cells in the different cortical areas, including membrane time constant, depolarizing sag, duration of individual action potentials, and spike-frequency adaptation. All of the electrophysiological variables ramped up before 7 months of age in V1, but continued to ramp up over a protracted period of time in area TE. These data suggest that the anatomical and electrophysiological profiles of pyramidal cells vary among cortical areas at birth, and continue to diverge into adulthood. Moreover, the data reveal that the use it or lose it notion of synaptic reinforcement may speak to only part of the story, use it but you still might lose it may be just as prevalent in the cerebral cortex.

  18. Chemical interactions with pyramidal neurons in layer 5 of the cerebral cortex: control of pain and anxiety.

    Adams, J D

    2009-01-01

    Pyramidal neurons in layer 5 of the cerebral cortex are involved in learning and memory and have complex connections with other neurons through a very large array of dendrites. These dendrites can switch between long term depression and long term potentiation depending on global summation of various inputs. The plasticity of the input into pyramidal neurons makes the neuronal output variable. Many interneurons in the cerebral cortex and distant neurons in other brain regions are involved in providing input to pyramidal neurons. All of these neurons and interneurons have neurotransmitters that act through receptors to provide input to pyramidal neurons. Serotonin is one of the important neurotransmitters involved with pyramidal neurons and has been implicated in psychosis, psychedelic states and what are called sacred dreams. This review will discuss the various chemicals and receptors that are important with pyramidal neurons including opioids, nicotine, scopolamine, psilocybin, LSD, mescaline, ergot alkaloids, salvinorin A, ergine and other compounds that interact with opioid, nicotinic, muscarinic and serotonergic receptors. The natural compounds provide clues to structure activity relationships with the receptors. It has been postulated that each receptor in the body has a natural agonist and antagonist, in addition to the normal neurotransmitters. It is common for natural antagonists and agonists to be peptides. Various possible peptide structures will be proposed for natural antagonists and agonists at each receptor. Natural antagonists and agonists may provide new ways to explore the functions of pyramidal neurons in normal health and pain management. PMID:19799545

  19. Pyramidal cells in V1 of African rodents are bigger more branched and more spiny than those in primates.

    Guy Elston

    2014-02-01

    Full Text Available Pyramidal cells are characterised by markedly different sized dendritic trees, branching patterns and spine density across the cortical mantle. Moreover, pyramidal cells have been shown to differ in structure among homologous cortical areas in different species; however, most of these studies have been conducted in primates. Whilst pyramidal cells have been quantified in a few cortical areas in some other species there are, as yet, no uniform comparative data on pyramidal cell structure in a homologous cortical area among species in different Orders. Here we studied layer III pyramidal cells in V1 of three species of rodents, the greater cane rat, highveld gerbil and four-striped mouse, by the same methodology used to sample data from layer III pyramidal cells in primates. The data reveal markedly different trends between rodents and primates: there is an appreciable increase in the size, branching complexity and number of spines in the dendritic trees of pyramidal cells with increasing size of V1 in the brain in rodents, whereas there is relatively little difference in primates. Moreover, pyramidal cells in rodents are larger, more branched and more spinous than those in primates. For example, the dendritic trees of pyramidal cells in V1 of the cane rat are nearly three times larger, and have more than ten times the number of spines in their basal dendritic trees, than those in V1 of the macaque (7900 and 600, respectively, which has a V1 40 times the size that of the cane rat. It remains to be determined to what extent these differences may result from developmental differences or reflect evolutionary and/or processing specializations.

  20. From ¡°Double Pyramid¡± Thoughts to Corporate Social Responsibility for Enterprise Employees

    Guiling Wei

    2013-01-01

    The purpose of this paper is to study corporate social responsibility for staffs based on the pyramid of Maslow¡¯s hierarchy of human needs and the pyramid of Carroll¡¯s corporate social responsibility. This research takes advantage of ¡°double pyramid¡± thoughts to discuss some enterprises lack of corporate social responsibility for their employees. Today, we are building of a harmonious society, each enterprise should not only realize the profit maximization, but also to meet the individual...

  1. The mode of synaptic activation of pyramidal neurons in the cat primary somatosensory cortex: an intracellular HRP study.

    Yamamoto, T; Samejima, A; Oka, H

    1990-01-01

    A total of 141 pyramidal neurons in the cat primary somatosensory cortex (SI) were recorded intracellularly under Nembutal anesthesia (7 in layer II, 43 in layer III, 8 in layer IV, 58 in layer V and 25 in layer VI). Most neurons were identified by intracellular staining with HRP, though some layer V pyramidal neurons were identified only electrophysiologically with antidromic activation of medullary pyramid (PT) or pontine nuclear (PN) stimulation. Excitatory synaptic potentials (EPSPs) were analyzed with stimulation of the superficial radial nerve (SR), the ventral posterolateral nucleus (VPL) in the thalamus and the thalamic radiation (WM). The pyramidal neurons in layers III and IV received EPSPs at the shortest latency: 9.1 +/- 2.1 ms (Mean +/- S.D.) for SR and 1.6 +/- 0.7 ms for VPL stimulation. Layer II pyramidal neurons also responded at a short latency to VPL stimulation (1.7 +/- 0.5 ms), though their mean latencies for SR-induced EPSPs were relatively longer (10.6 +/- 1.9 ms). The mean latencies were much longer in layers V and VI pyramidal neurons (10.2 +/- 2.4 ms and 2.9 +/- 1.5 ms in layer V pyramidal neurons and 9.9 +/- 2.5 ms and 2.8 +/- 1.6 ms in layer VI pyramidal ones, respectively for SR and VPL stimulation). The comparison of the latencies between VPL and WM stimulation indicates that most layer III-IV pyramidal neurons and some pyramidal cells in layers II, V and VI received monosynaptic inputs from VPL. These findings are consistent with morphological data on the laminar distribution of thalamocortical fibers, i.e., thalamocortical fibers terminate mainly in the deeper part of layers III and IV with some collaterals in layers V, VI and II-I. The time-sequences of the latencies of VPL-EPSPs indicate that corticocortical and/or transcallosal neurons (pyramidal neurons in layers II and III) fire first and are followed by firing of the output neurons projecting to the subcortical structures (pyramidal neurons in layers V and VI). PMID:2358022

  2. Development of a pyramidal wavefront sensor test-bench at INO

    Turbide, Simon; Wang, Min; Gauvin, Jonny; Martin, Olivier; Savard, Maxime; Bourqui, Pascal; Veran, Jean-Pierre; Deschenes, William; Anctil, Genevieve; Chateauneuf, François

    2013-12-01

    The key technical element of the adaptive optics in astronomy is the wavefront sensing (WFS). One of the advantages of the pyramid wavefront sensor (P-WFS) over the widely used Shack-Hartmann wavefront sensor seems to be the increased sensitivity in closed-loop applications. A high-sensitivity and large dynamic-range WFS, such as P-WFS technology, still needs to be further investigated for proper justification in future Extremely Large Telescopes application. At INO, we have recently carried out the optical design, testing and performance evaluation of a P-WFS bench setup. The optical design of the bench setup mainly consists of the super-LED fiber source, source collimator, spatial light modulator (SLM), relay lenses, tip-tilt mirror, Fourier-transforming lens, and a four-faceted glass pyramid with a large vertex angle as well as pupil re-imaged optics. The phase-only SLM has been introduced in the bench setup to generate atmospheric turbulence with a maximum phase shift of more than 2π at each pixel (256 grey levels). Like a modified Foucault knife-edge test, the refractive pyramid element is used to produce four images of the entrance pupil on a CCD camera. The Fourier-transforming lens, which is used before the pyramid prism, is designed for telecentric output to allow dynamic modulation (rotation of the beam around the pyramid-prism center) from a tip-tilt mirror. Furthermore, a P-WFS diffraction-based model has been developed. This model includes most of the system limitations such as the SLM discrete voltage steps and the CCD pixel pitch. The pyramid effects (edges and tip) are considered as well. The modal wavefront reconstruction algorithm relies on the construction of an interaction matrix (one for each modulation's amplitude). Each column of the interaction matrix represents the combination of the four pupil images for a given wavefront aberration. The nice agreement between the data and the model suggest that the limitation of the system is not the P

  3. Structured Dendritic Inhibition Supports Branch-Selective Integration in CA1 Pyramidal Cells.

    Bloss, Erik B; Cembrowski, Mark S; Karsh, Bill; Colonell, Jennifer; Fetter, Richard D; Spruston, Nelson

    2016-03-01

    Neuronal circuit function is governed by precise patterns of connectivity between specialized groups of neurons. The diversity of GABAergic interneurons is a hallmark of cortical circuits, yet little is known about their targeting to individual postsynaptic dendrites. We examined synaptic connectivity between molecularly defined inhibitory interneurons and CA1 pyramidal cell dendrites using correlative light-electron microscopy and large-volume array tomography. We show that interneurons can be highly selective in their connectivity to specific dendritic branch types and, furthermore, exhibit precisely targeted connectivity to the origin or end of individual branches. Computational simulations indicate that the observed subcellular targeting enables control over the nonlinear integration of synaptic input or the initiation and backpropagation of action potentials in a branch-selective manner. Our results demonstrate that connectivity between interneurons and pyramidal cell dendrites is more precise and spatially segregated than previously appreciated, which may be a critical determinant of how inhibition shapes dendritic computation. VIDEO ABSTRACT. PMID:26898780

  4. In Vivo Monosynaptic Excitatory Transmission between Layer 2 Cortical Pyramidal Neurons

    Jouhanneau, Jean-Sébastien; Kremkow, Jens; Dorrn, Anja L.; Poulet, James F.A.

    2015-01-01

    Summary Little is known about the properties of monosynaptic connections between identified neurons in vivo. We made multiple (two to four) two-photon targeted whole-cell recordings from neighboring layer 2 mouse somatosensory barrel cortex pyramidal neurons in vivo to investigate excitatory monosynaptic transmission in the hyperpolarized downstate. We report that pyramidal neurons form a sparsely connected (6.7% connectivity) network with an overrepresentation of bidirectional connections. The majority of unitary excitatory postsynaptic potentials were small in amplitude (1 mV. The coefficient of variation (CV = 0.74) could largely be explained by the presence of synaptic failures (22%). Both the CV and failure rates were reduced with increasing amplitude. The mean paired-pulse ratio was 1.15 and positively correlated with the CV. Our approach will help bridge the gap between connectivity and function and allow investigations into the impact of brain state on monosynaptic transmission and integration. PMID:26670044

  5. In Vivo Monosynaptic Excitatory Transmission between Layer 2 Cortical Pyramidal Neurons

    Jean-Sébastien Jouhanneau

    2015-12-01

    Full Text Available Little is known about the properties of monosynaptic connections between identified neurons in vivo. We made multiple (two to four two-photon targeted whole-cell recordings from neighboring layer 2 mouse somatosensory barrel cortex pyramidal neurons in vivo to investigate excitatory monosynaptic transmission in the hyperpolarized downstate. We report that pyramidal neurons form a sparsely connected (6.7% connectivity network with an overrepresentation of bidirectional connections. The majority of unitary excitatory postsynaptic potentials were small in amplitude (1 mV. The coefficient of variation (CV = 0.74 could largely be explained by the presence of synaptic failures (22%. Both the CV and failure rates were reduced with increasing amplitude. The mean paired-pulse ratio was 1.15 and positively correlated with the CV. Our approach will help bridge the gap between connectivity and function and allow investigations into the impact of brain state on monosynaptic transmission and integration.

  6. Resonance enhancement effects in Raman-enhancing pyramid-like V-shape groove microstructures

    Mechler, M; Mechler, A; McNaughton, D

    2009-01-01

    Microscopic pyramidal pits in a reflective surface, a geometry similar to a retroreflector, are frequently used to enhance signal strength. The enhancement effect is generally attributed to surface plasmons, however, the sub-wavelength to near-wavelength dimensions of the pyramidal 3D geometry suggest contributions from diffraction and near-field effects. Our theoretical analysis of the light intensity distribution in the similar (but simpler) 2D geometry assuming a perfect conductor screen, that is, in the absence of any plasmon effects, shows that interference patterns forming within the cavity cause a significant resonant increase in local intensity. Such effect can be important for many applications, especially for the widely used Raman spectroscopy. Resonant enhancement without plasmons of the emitted Raman signal due to enhanced local field amplitude is also possible, which implies that the geometry practically implements a Raman laser. Comparison of diffraction patterns obtained with near-field and far...

  7. Dynamic chest image analysis: model-based ventilation study with pyramid images

    Liang, Jianming; Jaervi, Timo; Kiuru, Aaro J.; Kormano, Martti; Svedstrom, Erkki; Virkki, Raimo

    1997-05-01

    The aim of the study 'dynamic chest image analysis' is to develop computing analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected at different phases of the respiratory/cardiac cycles. A multiresolutional method for ventilation study with an explicit ventilation model based on pyramid images is proposed in this paper. The ventilation model is sophisticated enough in coverage of both inhalation and exhalation phases, but also remains simple enough in model realization. This model plays a critical role in extracting accurate, geographic ventilation parameters; while the pyramid helps in understanding ventilation at multiple resolutions and speeding up the convergence process in optimization. A number of patients have been studied with a research prototype produced in MATLAB. The prototype has proven to be useful aid in dynamic pulmonary ventilation study. However, for clinical use, further work must be done in the future.

  8. Morphology cluster and prediction of growth of human brain pyramidal neurons

    Chao Yu; Zengxin Han; Wencong Zeng; Shenquan Liu

    2012-01-01

    Predicting neuron growth is valuable to understand the morphology of neurons, thus it is helpful in the research of neuron classification. This study sought to propose a new method of predicting the growth of human neurons using 1 907 sets of data in human brain pyramidal neurons obtained from the website of NeuroMorpho.Org. First, we analyzed neurons in a morphology field and used an expectation-maximization algorithm to specify the neurons into six clusters. Second, naive Bayes classifier was used to verify the accuracy of the expectation-maximization algorithm. Experiment results proved that the cluster groups here were efficient and feasible. Finally, a new method to rank the six expectation-maximization algorithm clustered classes was used in predicting the growth of human pyramidal neurons.

  9. The diamond pyramid structure in electroless copper deposit, its atomic model and molecular dynamics simulation

    In this paper, we report the discovery of the diamond pyramid structures in the electroless copper deposits on both epoxy and stainless steel substrates. The surface morphology of the structure was characterized with scanning electron microscope (SEM). According to the morphological feature of the structure, an atom model was brought forward in order to describe the possible mechanism of forming such structure. Molecular dynamics (MD) simulations were then carried out to investigate the growing process of the diamond pyramid structure. The final structures of the simulation were compared with the SEM images and the atomic model. The radial distribution function of the final structures of the simulation was compared with that calculated from the X-ray diffraction pattern of the electroless copper deposit sample

  10. The diamond pyramid structure in electroless copper deposit, its atomic model and molecular dynamics simulation

    Wu, X.; Sha, W.

    2008-12-01

    In this paper, we report the discovery of the diamond pyramid structures in the electroless copper deposits on both epoxy and stainless steel substrates. The surface morphology of the structure was characterized with scanning electron microscope (SEM). According to the morphological feature of the structure, an atom model was brought forward in order to describe the possible mechanism of forming such structure. Molecular dynamics (MD) simulations were then carried out to investigate the growing process of the diamond pyramid structure. The final structures of the simulation were compared with the SEM images and the atomic model. The radial distribution function of the final structures of the simulation was compared with that calculated from the X-ray diffraction pattern of the electroless copper deposit sample.

  11. Resolution Enhancement by Prediction of the High-Frequency Image Based on the Laplacian Pyramid

    Yang Seungjoon

    2006-01-01

    Full Text Available According to recent advances in digital image processing techniques, interest in high-quality images has been increased. This paper presents a resolution enhancement (RE algorithm based on the pyramid structure, in which Laplacian histogram matching is utilized for high-frequency image prediction. The conventional RE algorithms yield blurring near-edge boundaries, degrading image details. In order to overcome this drawback, we estimate an HF image that is needed for RE by utilizing the characteristics of the Laplacian images, in which the normalized histogram of the Laplacian image is fitted to the Laplacian probability density function (pdf, and the parameter of the Laplacian pdf is estimated based on the Laplacian image pyramid. Also, we employ a control function to remove overshoot artifacts in reconstructed images. Experiments with several test images show the effectiveness of the proposed algorithm.

  12. Growth of epitaxial micrometer-sized Cu- and Cu-Ni pyramides on silicon

    Hoffmann, Sarah; Ernst, Benedikt; Nowak, Regina; Seyffarth, Susanne; Krebs, Hans-Ulrich [Institut fuer Materialphysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

    2010-07-01

    Thin Cu and Cu-Ni films were prepared on Si(111) substrates using pulsed laser deposition (PLD) in ultra high vacuum. At elevated substrate temperatures above 200 C, either during deposition or afterwards, epitaxial growth of three dimensional pyramides with edge lengths of about five micrometers and heights up to 500 nm is observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the case of pure Cu, the base area of these islands is a triangle. With increasing Ni-content, shape changes occur, which can be explained by a reduction of surface diffusion. The influence of the SiO{sub 2} layer thickness and the formation of a Cu-Si interlayer was studied by ellipsometry. The transformation of the Cu and Cu-Ni films into the pyramids during heating were studied by resistance and X-ray measurements.

  13. Pyramidal Edge Detection Method Based on AWFM Filtering and Fuzzy Linking Model

    2002-01-01

    A novel multiresolution pyramidal edge detector, based on adaptive weighted fuzzy mean(AWFM)filtering and fuzzy linking model, is presented in this paper. The algorithm first constructs a pyramidal structure by repetitive AWFM filtering and subsampling of original image. Then it utilizes multiple heuristic linking criteria between the edge nodes of two adjacent levels and considers the linkage as a fuzzy model, which is trained offline. Through this fuzzy linking model, the boundaries detected at coarse resolution are propagated and refined to the bottom level from the coarse-to fine edge detection. The validation experiment results demonstrate that the proposed approach has superior performance compared with standard fixed resolution detector andprevious multiresolution approach, especially in impulse noise environment.

  14. Morphology of Pyramidal Neurons in the Rat Prefrontal Cortex: Lateralized Dendritic Remodeling by Chronic Stress

    Claudia Perez-Cruz

    2007-01-01

    Full Text Available The prefrontal cortex (PFC plays an important role in the stress response. We filled pyramidal neurons in PFC layer III with neurobiotin and analyzed dendrites in rats submitted to chronic restraint stress and in controls. In the right prelimbic cortex (PL of controls, apical and distal dendrites were longer than in the left PL. Stress reduced the total length of apical dendrites in right PL and abolished the hemispheric difference. In right infralimbic cortex (IL of controls, proximal apical dendrites were longer than in left IL, and stress eliminated this hemispheric difference. No hemispheric difference was detected in anterior cingulate cortex (ACx of controls, but stress reduced apical dendritic length in left ACx. These data demonstrate interhemispheric differences in the morphology of pyramidal neurons in PL and IL of control rats and selective effects of stress on the right hemisphere. In contrast, stress reduced dendritic length in the left ACx.

  15. Pyramidal Fin Arrays Performance Using Streamwise Anisotropic Materials by Cold Spray Additive Manufacturing

    Cormier, Yannick; Dupuis, Philippe; Jodoin, Bertrand; Corbeil, Antoine

    2016-01-01

    This work evaluates the thermal and hydrodynamic performance of pyramidal fin arrays produced using cold spray as an additive manufacturing process. Near-net-shaped pyramidal fin arrays of pure aluminum, pure nickel, and stainless steel 304 were manufactured. Fin array characterization such as fin porosity level and surface roughness evaluation was performed. The thermal conductivities of the three different coating materials were measured by laser flash analysis. The results obtained show a lower thermal efficiency for stainless steel 304, whereas the performances of the aluminum and nickel fin arrays are similar. This result is explained by looking closely at the fin and substrate roughness induced by the cold gas dynamic additive manufacturing process. The multi-material fin array sample has a better thermal efficiency than stainless steel 304. The work demonstrates the potential of the process to produce streamwise anisotropic fin arrays as well as the benefits of such arrays.

  16. Conditions for entangled photon emission from (111)B site-controlled pyramidal quantum dots

    Juska, G., E-mail: gediminas.juska@tyndall.ie; Murray, E.; Dimastrodonato, V.; Chung, T. H.; Moroni, S. T.; Gocalinska, A.; Pelucchi, E. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

    2015-04-07

    A study of highly symmetric site-controlled pyramidal In{sub 0.25}Ga{sub 0.75}As quantum dots (QDs) is presented. It is discussed that polarization-entangled photons can be also obtained from pyramidal QDs of different designs from the one already reported in Juska et al. [Nat. Photonics 7, 527 (2013)]. Moreover, some of the limitations for a higher density of entangled photon emitters are addressed. Among these issues are (1) a remaining small fine-structure splitting and (2) an effective QD charging under non-resonant excitation conditions, which strongly reduce the number of useful biexciton-exciton recombination events. A possible solution of the charging problem is investigated exploiting a dual-wavelength excitation technique, which allows a gradual QD charge tuning from strongly negative to positive and, eventually, efficient detection of entangled photons from QDs, which would be otherwise ineffective under a single-wavelength (non-resonant) excitation.

  17. Single-crystal diamond pyramids: synthesis and application for atomic force microscopy

    Tuyakova, Feruza T.; Obraztsova, Ekaterina A.; Ismagilov, Rinat R.

    2016-03-01

    Here we present the results of investigations aimed at the development and testing of robust, chemically inert single-crystal diamond probes for atomic force microscopy (AFM). The probes were prepared by assembling common silicon probes with micrometer-sized pyramid-shaped single-crystal diamonds (SCD). The SCD were obtained by the selective thermal oxidation of the polycrystalline films grown by chemical vapor deposition. Electrostatic spray of adhesive coating onto silicon probes was used to attach individual SCD. Geometrical parameters of produced AFM SCD probes were revealed with transmission electron microscopy: the apex angle of the pyramidal diamond crystallite was ˜10 deg, and the curvature radius at the apex was ˜2 to 10 nm. The diamond AFM probes were used for surface imaging of deoxyribonucleic acid deposited on graphite substrate. Obtained results demonstrate high efficiency of the diamond AFM probes, allowing improvement of the image quality compared to standard silicon probes.

  18. Neurofilament light mutation causes hereditary motor and sensory neuropathy with pyramidal signs.

    Hashiguchi, Akihiro; Higuchi, Yujiro; Nomura, Miwa; Nakamura, Tomonori; Arata, Hitoshi; Yuan, Junhui; Yoshimura, Akiko; Okamoto, Yuji; Matsuura, Eiji; Takashima, Hiroshi

    2014-12-01

    To identify novel mutations causing hereditary motor and sensory neuropathy (HMSN) with pyramidal signs, a variant of Charcot-Marie-Tooth disease (CMT), we screened 28 CMT and related genes in four members of an affected Japanese family. Clinical features included weakness of distal lower limb muscles, foot deformity, and mild sensory loss, then late onset of progressive spasticity. Electrophysiological studies revealed widespread neuropathy. Electron microscopic analysis showed abnormal mitochondria and mitochondrial accumulation in the neurons and Schwann cells. Brain magnetic resonance imaging (MRI) revealed an abnormally thin corpus callosum. In all four, microarrays detected a novel heterozygous missense mutation c.1166A>G (p.Y389C) in the gene encoding the light-chain neurofilament protein (NEFL), indicating that NEFL mutations can result in a HMSN with pyramidal signs phenotype. PMID:25583183

  19. Sulfolobus Turreted Icosahedral Virus c92 Protein Responsible for the Formation of Pyramid-Like Cellular Lysis Structures

    Snyder, Jamie C; Brumfield, Susan K; Peng, Nan;

    2011-01-01

    Host cells infected by Sulfolobus turreted icosahedral virus (STIV) have been shown to produce unusual pyramid-like structures on the cell surface. These structures represent a virus-induced lysis mechanism that is present in Archaea and appears to be distinct from the holin/endolysin system...... described for DNA bacteriophages. This study investigated the STIV gene products required for pyramid formation in its host Sulfolobus solfataricus. Overexpression of STIV open reading frame (ORF) c92 in S. solfataricus alone is sufficient to produce the pyramid-like lysis structures in cells. Gene...... disruption of c92 within STIV demonstrates that c92 is an essential protein for virus replication. Immunolocalization of c92 shows that the protein is localized to the cellular membranes forming the pyramid-like structures....

  20. Gravitational attraction of a vertical pyramid model of flat top-and-bottom with depth-wise parabolic density variation

    Anand P Gokula; Rambhatla G Sastry

    2015-12-01

    In 3D gravity modelling, right rectangular vertical prism model with linear and nonlinear density and polyhedral bodies with linear density variation exist in geophysical literature. Here, we propose a vertical pyramid model with depth-wise parabolic density contrast variation. Initially, we validate our analytic expression against the gravity effect of a right rectangular parallelepiped of constant density contrast. We provide two synthetic examples and a case study for illustrating the effectiveness of our pyramid model in gravity modelling. The included case study of Los Angeles basin, California demonstrates the comparative advantages of our pyramid model over a conventional right rectangular vertical prism model. Our pyramid model could be quite effective as a building block for evaluating the gravity effect of an arbitrarily-shaped 3D or 2.5-D source(s).

  1. ETHICS AND PHILANTHROPY IN THE FIELD OF CORPORATE SOCIAL RESPONSIBILITY PYRAMID

    Marija Mihaljevic; Ivana Tokic

    2015-01-01

    Corporate social responsibility (CSR) is a concept which is based on the orientation of economic subjects for the benefit of the community. CSR has a long and rich tradition of existence and activities but in the Republic of Croatia CSR is still developing. In this article, CSR is seen through Carroll’s pyramid of social responsibility which includes economic, legal, ethical and philanthropic responsibilities of business subjects. Economic and legal responsibilities which are core responsibil...

  2. Corporate Social Responsibility Boosts Value Creation at the Base of the Pyramid

    André, Thomas

    2014-01-01

    Multinational enterprises (MNEs) have embraced the possibility to find growth or strategic opportunities by targeting the Base of the Pyramid (BoP) segment, while contributing to alleviate poverty. Taking stock of the notorious early BoP initiatives shows that the bet made upon this responsible commitment is not yet won. Indeed, some were relegated to philanthropic programmes or simply dismantled, highlighting a tension to combine both societal and financial sustainability. The paper question...

  3. Nonlinear optics and spectroscopy at the nanoscale with a hollow-pyramid aperture SNOM

    Biagioni, P [Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Celebrano, M [Istituto di Fotonica e Nanotecnologie, CNR, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Polli, D [Istituto di Fotonica e Nanotecnologie, CNR, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Labardi, M [PolyLab CNR-INFM, largo Bruno Pontecorvo 3, 56127 Pisa (Italy); Zavelani-Rossi, M [Istituto di Fotonica e Nanotecnologie, CNR, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Cerullo, G [Istituto di Fotonica e Nanotecnologie, CNR, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Finazzi, M [Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Duo, L [Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy)

    2007-03-15

    We report on a novel near-field microscope in which ultrashort laser pulses are coupled into hollow-pyramid cantilever probes. The high throughput, absence of polarization pinning and absence of chirping, which are premium features of such probes, enable obtaining sufficient peak power in the near-field to perform nonlinear optical experiments. We show experimental results on second-harmonic generation from metal nanostructures and two-photon excitation of fluorescent conjugated polymers on the subwavelength scale.

  4. Corporate Social Entrepreneurship at the Bottom of the Economic Pyramid:Antecedents and Outcomes in India

    Tasavori, Misagh

    2012-01-01

    Increasingly, developed countries' markets, which are usually characterized by wealthy customers, are getting saturated. This has necessitated that multinational corporations (MNCs) seek new solutions for their future growth and profitability. One of the markets that has attracted the attention of MNCs is the bottom of the economic pyramid (BOP), which comprises four billion people. However, reaching this market, characterized as having a low income of less than $2 a day, is not easily achiev...

  5. Nonlinear optics and spectroscopy at the nanoscale with a hollow-pyramid aperture SNOM

    We report on a novel near-field microscope in which ultrashort laser pulses are coupled into hollow-pyramid cantilever probes. The high throughput, absence of polarization pinning and absence of chirping, which are premium features of such probes, enable obtaining sufficient peak power in the near-field to perform nonlinear optical experiments. We show experimental results on second-harmonic generation from metal nanostructures and two-photon excitation of fluorescent conjugated polymers on the subwavelength scale

  6. Renovating the Pyramid of Needs: Contemporary Extensions Built Upon Ancient Foundations

    Kenrick, Douglas T.; Griskevicius, Vladas; Neuberg, Steven L.; Schaller, Mark

    2010-01-01

    Maslow’s pyramid of human needs, proposed in 1943, has been one of the most cognitively contagious ideas in the behavioral sciences. Anticipating later evolutionary views of human motivation and cognition, Maslow viewed human motives as based in innate and universal predispositions. We revisit the idea of a motivational hierarchy in light of theoretical developments at the interface of evolutionary biology, anthropology, and psychology. After considering motives at three different levels of a...

  7. The diamond pyramid structure in electroless copper deposit, its atomic model and molecular dynamics simulation

    Sha, Wei

    2008-01-01

    In this seminar, I will talk about the discovery of the diamond pyramid structures in the electroless copper deposits on both epoxy and stainless steel substrates. The surface morphology of the structure was characterized with scanning electron microscopy (SEM). According to the morphological feature of the structure, an atom model was brought forward in order to describe the possible mechanism of forming such structure. Molecular dynamics simulations were then carried out to investigate the ...

  8. Delayed oedema in the pyramidal tracts remote from intracerebral missile path following gunshot injury

    A 60-year-old man developed a severe left hemiparesis and central facial palsy, accompanied by somnolence and dysarthria 9 days after a gunshot wound to the right temporal region, from which he slowly recovered over 3 months. MRI disclosed bilateral oedema of the pyramidal tracts. This was interpreted as a consequence of the impact of the pressure wave caused by the bullet, after excluding an infectious or vascular cause. (orig.)

  9. Thyroid Metastasis in Pyramidal Lobe from Renal Cell Carcinoma: A Case Report

    Thyroid metastasis is rare. The most common primary malignancy of thyroid metastasis worldwide is known to be renal cell carcinoma, but the most common primary malignancy in South Korea is breast cancer. Many studies have reported that primary renal cell carcinoma is almost unilateral and thyroid metastasis from renal cell carcinoma is a nearly ipsilateral, single lesion. We report a case of pyramidal lobe metastasis from renal cell carcinoma.

  10. Sierpinski Pyramidal Antenna Loaded With a Cutoff Open-Ended Waveguide

    Hebib, Sami; Aubert, Hervé; Pascal, Olivier; Fonseca, Nelson; Ries, Lionel; Lopez, Jean-Marc

    2009-01-01

    International audience A new pyramidal antenna for satellite application is presented. Sierpinski triangle antennas are chosen as radiating elements for their multiband features. The ground plane of the antenna is perforated and loaded with a cutoff open-ended waveguide: this original configuration leads to a good tradeoff between rear radiation and impedance matching. Ideal trap-loads are used to improve the multiband operation of the Sierpinski radiating elements. The antenna radiates ci...

  11. Multiband Pyramidal Antenna Loaded With a Cutoff Open-Ended Waveguide

    Hebib, Sami; Aubert, Hervé; Pascal, Olivier; Fonseca, Nelson; Ries, Lionel; Lopez, Jean-Marc

    2009-01-01

    International audience An original and flexible pyramidal antenna for satellite or terrestrial application services is presented. The ground plane of the antenna is perforated and loaded with a cutoff open-ended waveguide: this original configuration leads to a good tradeoff between rear radiation and impedance matching. Trap-loads are used to achieve multiband operation while frequency agility may be simply obtained by loading the radiating element by radio-frequency switches. The antenna...

  12. Extreme Inverted Trophic Pyramid of Reef Sharks Supported by Spawning Groupers.

    Mourier, Johann; Maynard, Jeffrey; Parravicini, Valeriano; Ballesta, Laurent; Clua, Eric; Domeier, Michael L; Planes, Serge

    2016-08-01

    The extent of the global human footprint [1] limits our understanding of what is natural in the marine environment. Remote, near-pristine areas provide some baseline expectations for biomass [2, 3] and suggest that predators dominate, producing an inverted biomass pyramid. The southern pass of Fakarava atoll-a biosphere reserve in French Polynesia-hosts an average of 600 reef sharks, two to three times the biomass per hectare documented for any other reef shark aggregations [4]. This huge biomass of predators makes the trophic pyramid inverted. Bioenergetics models indicate that the sharks require ∼90 tons of fish per year, whereas the total fish production in the pass is ∼17 tons per year. Energetic theory shows that such trophic structure is maintained through subsidies [5-9], and empirical evidence suggests that sharks must engage in wide-ranging foraging excursions to meet energy needs [9, 10]. We used underwater surveys and acoustic telemetry to assess shark residency in the pass and feeding behavior and used bioenergetics models to understand energy flow. Contrary to previous findings, our results highlight that sharks may overcome low local energy availability by feeding on fish spawning aggregations, which concentrate energy from other local trophic pyramids. Fish spawning aggregations are known to be targeted by sharks, but they were previously believed to play a minor role representing occasional opportunistic supplements. This research demonstrates that fish spawning aggregations can play a significant role in the maintenance of local inverted pyramids in pristine marine areas. Conservation of fish spawning aggregations can help conserve shark populations, especially if combined with shark fishing bans. PMID:27476598

  13. The neural code between neocortical pyramidal neurons depends on neurotransmitter release probability

    Tsodyks, Misha V.; Markram, Henry

    1997-01-01

    Although signaling between neurons is central to the functioning of the brain, we still do not understand how the code used in signaling depends on the properties of synaptic transmission. Theoretical analysis combined with patch clamp recordings from pairs of neocortical pyramidal neurons revealed that the rate of synaptic depression, which depends on the probability of neurotransmitter release, dictates the extent to which firing rate and temporal coherence of action potentials within a pre...

  14. Pyramid Coarse Sun Sensing for NASA SSTI "Clark" Safe-Hold Mode

    Benton, Jeff

    1996-01-01

    This paper describes an innovative approach to solving the Sun-pointing problem using a pyramid configuration of Coarse Sun Sensor (CSS) cells. In safe-hold mode, the Small Spacecraft Technology Initiative (SSTI) Clark spacecraft must keep its solar arrays towards the Sun using only CSS cells to sense the Sun. Unfortunately, Earth albedo degrades the accuracy of the Sun vector from these cells. Two CSS configurations are considered. A traditional configuration has cells mounted flat on each s...

  15. Conserved size and periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex.

    Naumann, Robert K; Ray, Saikat; Prokop, Stefan; Las, Liora; Heppner, Frank L; Brecht, Michael

    2016-03-01

    To understand the structural basis of grid cell activity, we compare medial entorhinal cortex architecture in layer 2 across five mammalian species (Etruscan shrews, mice, rats, Egyptian fruit bats, and humans), bridging ∼100 million years of evolutionary diversity. Principal neurons in layer 2 are divided into two distinct cell types, pyramidal and stellate, based on morphology, immunoreactivity, and functional properties. We confirm the existence of patches of calbindin-positive pyramidal cells across these species, arranged periodically according to analyses techniques like spatial autocorrelation, grid scores, and modifiable areal unit analysis. In rodents, which show sustained theta oscillations in entorhinal cortex, cholinergic innervation targeted calbindin patches. In bats and humans, which only show intermittent entorhinal theta activity, cholinergic innervation avoided calbindin patches. The organization of calbindin-negative and calbindin-positive cells showed marked differences in entorhinal subregions of the human brain. Layer 2 of the rodent medial and the human caudal entorhinal cortex were structurally similar in that in both species patches of calbindin-positive pyramidal cells were superimposed on scattered stellate cells. The number of calbindin-positive neurons in a patch increased from ∼80 in Etruscan shrews to ∼800 in humans, only an ∼10-fold over a 20,000-fold difference in brain size. The relatively constant size of calbindin patches differs from cortical modules such as barrels, which scale with brain size. Thus, selective pressure appears to conserve the distribution of stellate and pyramidal cells, periodic arrangement of calbindin patches, and relatively constant neuron number in calbindin patches in medial/caudal entorhinal cortex. PMID:26223342

  16. PIXE, PIGE and NMR study of the masonry of the pyramid of Cheops at Giza

    The mystery of the construction of the great pyramids of Egypt could be elucidated by physico-chemical measurements on small pieces of the material. In this paper, we give several arguments against the present point of view of most Egyptologists who do not admit another method than hewn blocks. We give several pieces of evidence that the masonry was entirely built by a moulding procedure involving the use of ingredients that were all available in the region of Cairo

  17. Transforming Markets, Increasing Access : Early Lessons on Base-of-the-Pyramid Market Development in Sanitation

    Pedi, Danielle; Davies, Will

    2013-01-01

    The four billion global consumers at the base of the pyramid (BOP) - those earning less than two dollars a day - are increasingly recognized by the private sector as a major untapped market segment. The sanitation industry is no exception. Across sub-Saharan Africa, more than half of the population lives without access to minimum levels of improved sanitation. Beyond the reach of urban sew...

  18. Tiled top-down pyramids and segmentation of large histological images

    Goffe, Romain; Brun, Luc; Damiand, Guillaume

    2011-01-01

    Recent microscopic imaging systems such as whole slide scanners provide very large (up to 18GB) high resolution images. Such amounts of memory raise major issues that prevent usual image representation models from being used. Moreover, using such high resolution images, global image features, such as tissues, do not clearly appear at full resolution. Such images contain thus different hierarchical information at different resolutions. This paper presents the model of tiled top-down pyramids w...

  19. A cognitive approach to the topography of the 12th dynasty pyramids

    Magli, Giulio

    2010-01-01

    The topography of the royal pyramids of the 12th dynasty is investigated in its historical and chronological context, in order to highlight connections between the architectural choices, the religious ideas and the traditions inspiring the reign of the corresponding pharaohs. A close, explicit connection with the double building projects carried out more than six centuries before by Snefru at Dahshur and at Meidum-Seila comes out. This connection involved geometry, perspective and astronomica...

  20. Foundations of Meta-Pyramids: Languages vs. Metamodels -- Episode II: Story of Thotus the Baboon1

    Favre, Jean-Marie

    2005-01-01

    Despite the recent interest for Model Driven Engineering approaches, the so-called four-layers metamodelling architecture is subject to a lot of debate. The relationship that exists between a model and a metamodel is often called instanceOf, but this terminology, which comes directly from the object oriented technology, is not appropriate for the modelling of similar meta-pyramids in other domains. The goal of this paper is to study which are the foundations of the meta-pyra...

  1. Completely empty pyramids on integer lattices and two-dimensional faces of multidimensional continued fractions

    Karpenkov, Oleg

    2005-01-01

    In this paper we develop an integer-affine classification of three-dimensional multistory completely empty convex marked pyramids. We apply it to obtain the complete lists of compact two-dimensional faces of multidimensional continued fractions lying in planes with integer distances to the origin equal 2, 3, 4 ... The faces are considered up to the action of the group of integer-linear transformations. In conclusion we formulate some actual unsolved problems associated with the generalization...

  2. The Disconcerting Pyramids of Poverty and Inequality of Sub-Saharan Africa

    Paulo Silva Lopes

    2005-01-01

    Poverty and inequality in Sub-Saharan Africa (SSA) should not be ascertained only on the basis of scarce and unreliable income distribution statistics, but should also take into account social conditions. Recent, widely disseminated claims that poverty and inequality have increased over the past 30 years are based on regional income estimates with falling medians and rising upper variances over that period. Graphically, this translates into pyramid-shaped income distributions that, perversely...

  3. Anatomy and physiology of the thick-tufted layer 5 pyramidal neuron

    Srikanth eRamaswamy; Henry eMarkram

    2015-01-01

    The thick-tufted layer 5 (TTL5) pyramidal neuron is one of the most extensively studied neuron types in the mammalian neocortex and has become a benchmark for understanding information processing in excitatory neurons. By virtue of having the widest local axonal and dendritic arborization, the TTL5 neuron encompasses various local neocortical neurons and thereby defines the dimensions of neocortical microcircuitry. The TTL5 neuron integrates input across all neocortical layers and is the prin...

  4. Morphology cluster and prediction of growth of human brain pyramidal neurons★

    Yu, Chao; Han, Zengxin; Zeng, Wencong; Liu, Shenquan

    2012-01-01

    Predicting neuron growth is valuable to understand the morphology of neurons, thus it is helpful in the research of neuron classification. This study sought to propose a new method of predicting the growth of human neurons using 1 907 sets of data in human brain pyramidal neurons obtained from the website of NeuroMorpho.Org. First, we analyzed neurons in a morphology field and used an expectation-maximization algorithm to specify the neurons into six clusters. Second, naive Bayes classifier w...

  5. Ray system in lasers, nonlinear arithmetic pyramid and nonlinear arithmetic triangles

    Yurkin, Alexander

    2013-01-01

    The paper describes a system of rays declining at small angles in lasers. The correlation between a group of rays and binomial coefficients is shown. The correlation of distribution of rays in the system of numbers placed in a three-dimensional table, the nonlinear arithmetic pyramid is shown. Two types of nonlinear arithmetic triangles are considered. Various types of partitions of integers is described.

  6. Organizational Challenges of Multinational Corporations at the Base of the Pyramid: An Action-research Inquiry

    Perrot, François

    2013-01-01

    To what extent and how does a multinational corporation adapt its strategy and organizational capabilities in order to address markets at the Base of the Pyramid? This paper builds on the results of a three-year action-research program conducted with Lafarge, a global building materials company and introduces a strategic framework which opposes two types of approaches of such markets: a licence-to-operate approach, and a business opportunityseeking approach. The article analyzes how the compa...

  7. Sustained competitive advantage of different sized multinational corporations in rural base of the pyramid markets

    Geuting, Paul

    2016-01-01

    This thesis explores how multinational corporations of different sizes create barriers to imitation and therefore sustain competitive advantage in rural and informal Base of the Pyramid economies. These markets require close cooperation with local partners in a dynamic environment that lacks imposable property rights and follows a different rationale than developed markets. In order to explore how competitive advantage is sustained by different sized multinational corporations at the Base of ...

  8. Thyroid Metastasis in Pyramidal Lobe from Renal Cell Carcinoma: A Case Report

    Jung, Hyung Seok; Kim, Dong Wook; Kim, Sang Su [Dept. of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of); Jung, Soo Jin [Dept. of Pathology, Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2011-06-15

    Thyroid metastasis is rare. The most common primary malignancy of thyroid metastasis worldwide is known to be renal cell carcinoma, but the most common primary malignancy in South Korea is breast cancer. Many studies have reported that primary renal cell carcinoma is almost unilateral and thyroid metastasis from renal cell carcinoma is a nearly ipsilateral, single lesion. We report a case of pyramidal lobe metastasis from renal cell carcinoma.

  9. Delayed oedema in the pyramidal tracts remote from intracerebral missile path following gunshot injury

    Thiex, R.; Uhl, E. [Department of Neurosurgery, Aachen University, Pauwelsstrasse 30, 52057, Aachen (Germany); Thron, A. [Department of Neuroradiology, Aachen University, Pauwelsstrasse 30, 52057, Aachen (Germany)

    2004-02-01

    A 60-year-old man developed a severe left hemiparesis and central facial palsy, accompanied by somnolence and dysarthria 9 days after a gunshot wound to the right temporal region, from which he slowly recovered over 3 months. MRI disclosed bilateral oedema of the pyramidal tracts. This was interpreted as a consequence of the impact of the pressure wave caused by the bullet, after excluding an infectious or vascular cause. (orig.)

  10. Variable-geometry solar sailing: the possibilities of the quasi-rhombic pyramid

    Ceriotti, Matteo; Harkness, Patrick; McRobb, Malcolm

    2014-01-01

    Variable geometry solar sailing potentially offers enhanced delta-V capabilities and new orbital solutions. We propose a device with such capabilities, based upon an adjustable quasi-rhombic pyramid sail geometry, and examine the benefits that can be derived from this additional flexibility. The enabling technology for this concept is the bevel crux drive, which can maintain tension in the solar sail across a wide range of apex angles. This paper explores the concept of such a device, discuss...

  11. Thalamocortical input onto layer 5 pyramidal neurons measured using quantitative large-scale array tomography.

    Rah, Jong-Cheol; Bas, Erhan; Colonell, Jennifer; Mishchenko, Yuriy; Karsh, Bill; Fetter, Richard D; Myers, Eugene W; Chklovskii, Dmitri B; Svoboda, Karel; Harris, Timothy D; Isaac, John T R

    2013-01-01

    The subcellular locations of synapses on pyramidal neurons strongly influences dendritic integration and synaptic plasticity. Despite this, there is little quantitative data on spatial distributions of specific types of synaptic input. Here we use array tomography (AT), a high-resolution optical microscopy method, to examine thalamocortical (TC) input onto layer 5 pyramidal neurons. We first verified the ability of AT to identify synapses using parallel electron microscopic analysis of TC synapses in layer 4. We then use large-scale array tomography (LSAT) to measure TC synapse distribution on L5 pyramidal neurons in a 1.00 × 0.83 × 0.21 mm(3) volume of mouse somatosensory cortex. We found that TC synapses primarily target basal dendrites in layer 5, but also make a considerable input to proximal apical dendrites in L4, consistent with previous work. Our analysis further suggests that TC inputs are biased toward certain branches and, within branches, synapses show significant clustering with an excess of TC synapse nearest neighbors within 5-15 μm compared to a random distribution. Thus, we show that AT is a sensitive and quantitative method to map specific types of synaptic input on the dendrites of entire neurons. We anticipate that this technique will be of wide utility for mapping functionally-relevant anatomical connectivity in neural circuits. PMID:24273494

  12. A general formalism for Fourier based Wave Front Sensing: application to the Pyramid wave front sensors

    Fauvarque, Olivier; Fusco, Thierry; Sauvage, Jean-François; Giraut, Orion

    2016-01-01

    In this article, we compare a set of Wave Front Sensors (WFS) based on Fourier filtering technique. In particular, this study explores the "class of pyramidal WFS" defined as the 4 faces pyramid WFS, all its recent variations (6, 8 faces, the flattened PWFS, etc.) and also some new WFSs as the flattened cone WFS or the 3 faces pyramid WFS. In the first part, we describe such a sensors class thanks to the optical parameters of the Fourier filtering mask and the modulation parameters. In the second part, we use the unified formalism to create a set of performance criteria: size of the signal on the detector, efficiency of incoming flux, sensitivity, linear range and chromaticity. In the third part, we show the influence of the previous optical and modulation parameters on these performance criteria. This exhaustive study allows to know how to optimize the sensor regarding to performance specifications. We show in particular that the number of faces has influence on the number of pixels required to do the wave f...

  13. Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats

    Yang Wang; Zhouyan Feng; Jing Wang; Xiaojing Zheng

    2014-01-01

    The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear. To investigate the behavior of indi-vidual neurons in response to somatosensory inputs in the hippocampal CA1 region, we recorded and analyzed changes in local ifeld potentials and the ifring rates of individual pyramidal cells and interneurons during tail clamping in urethane-anesthetized rats. We also explored the mechanisms underlying the neuronal responses. Somatosensory stimulation, in the form of tail clamping, chan-ged local ifeld potentials into theta rhythm-dominated waveforms, decreased the spike ifring of py-ramidal cells, and increased interneuron ifring. In addition, somatosensory stimulation attenuated orthodromic-evoked population spikes. These results suggest that somatosensory stimulation sup-presses the excitability of pyramidal cells in the hippocampal CA1 region. Increased inhibition by local interneurons might underlie this effect. These ifndings provide insight into the mechanisms of signal processing in the hippocampus and suggest that sensory stimulation might have thera-peutic potential for brain disorders associated with neuronal hyperexcitability.

  14. Dielectrophoresis-Assisted Raman Spectroscopy of Intravesicular Analytes on Metallic Pyramids.

    Barik, Avijit; Cherukulappurath, Sudhir; Wittenberg, Nathan J; Johnson, Timothy W; Oh, Sang-Hyun

    2016-02-01

    Chemical analysis of membrane-bound containers such as secretory vesicles, organelles, and exosomes can provide insights into subcellular biology. These containers are loaded with a range of important biomolecules, which further underscores the need for sensitive and selective analysis methods. Here we present a metallic pyramid array for intravesicular analysis by combining site-selective dielectrophoresis (DEP) and Raman spectroscopy. Sharp pyramidal tips act as a gradient force generator to trap nanoparticles or vesicles from the solution, and the tips are illuminated by a monochromatic light source for concurrent spectroscopic detection of trapped analytes. The parameters suitable for DEP trapping were optimized by fluorescence microscopy, and the Raman spectroscopy setup was characterized by a nanoparticle based model system. Finally, vesicles loaded with 4-mercaptopyridine were concentrated at the tips and their Raman spectra were detected in real time. These pyramidal tips can perform large-area array-based trapping and spectroscopic analysis, opening up possibilities to detect molecules inside cells or cell-derived vesicles. PMID:26751756

  15. Astronomy, topography and dynastic history in the Age of the Pyramids

    Magli, Giulio

    2009-01-01

    It is known since the 19th century that in the layout of the pyramid field of the pharaohs of the 4th Egyptian dynasty at Giza, a main axis exists. Indeed, the south-east corners of these monuments align towards the site of the temple of Heliopolis, which was plainly visible in ancient times. It was later discovered that a similar situation occurs in the main pyramid field of the subsequent dynasty at Abu Sir. Here, the north-west corners of three chronologically successive pyramids again voluntarily align towards Heliopolis. However, the temple was in this case not visible, due to the rock outcrop- today occupied by the Cairo citadel - which blocks the view. In the present paper, a multi-disciplinary approach based on historical, topographical and archaeoastronomical analysis is developed in an attempt at understanding this peculiar feature, which governed from the very beginning the planning of such wonderful monuments. A general pattern arises, which appears to have inspired the choice of the sites and the...

  16. Use of Multi-Resolution Wavelet Feature Pyramids for Automatic Registration of Multi-Sensor Imagery

    Zavorin, Ilya; LeMoigne, Jacqueline

    2003-01-01

    The problem of image registration, or alignment of two or more images representing the same scene or object, has to be addressed in various disciplines that employ digital imaging. In the area of remote sensing, just like in medical imaging or computer vision, it is necessary to design robust, fast and widely applicable algorithms that would allow automatic registration of images generated by various imaging platforms at the same or different times, and that would provide sub-pixel accuracy. One of the main issues that needs to be addressed when developing a registration algorithm is what type of information should be extracted from the images being registered, to be used in the search for the geometric transformation that best aligns them. The main objective of this paper is to evaluate several wavelet pyramids that may be used both for invariant feature extraction and for representing images at multiple spatial resolutions to accelerate registration. We find that the band-pass wavelets obtained from the Steerable Pyramid due to Simoncelli perform better than two types of low-pass pyramids when the images being registered have relatively small amount of nonlinear radiometric variations between them. Based on these findings, we propose a modification of a gradient-based registration algorithm that has recently been developed for medical data. We test the modified algorithm on several sets of real and synthetic satellite imagery.

  17. Use of multiresolution wavelet feature pyramids for automatic registration of multisensor imagery

    Zavorin, Ilya; Le Moigne, Jacqueline

    2005-01-01

    The problem of image registration, or the alignment of two or more images representing the same scene or object, has to be addressed in various disciplines that employ digital imaging. In the area of remote sensing, just like in medical imaging or computer vision, it is necessary to design robust, fast, and widely applicable algorithms that would allow automatic registration of images generated by various imaging platforms at the same or different times and that would provide subpixel accuracy. One of the main issues that needs to be addressed when developing a registration algorithm is what type of information should be extracted from the images being registered, to be used in the search for the geometric transformation that best aligns them. The main objective of this paper is to evaluate several wavelet pyramids that may be used both for invariant feature extraction and for representing images at multiple spatial resolutions to accelerate registration. We find that the bandpass wavelets obtained from the steerable pyramid due to Simoncelli performs best in terms of accuracy and consistency, while the low-pass wavelets obtained from the same pyramid give the best results in terms of the radius of convergence. Based on these findings, we propose a modification of a gradient-based registration algorithm that has recently been developed for medical data. We test the modified algorithm on several sets of real and synthetic satellite imagery.

  18. Serotonin3 receptor agonists attenuate glutamate-induced firing in rat hippocampal CA1 pyramidal cells.

    Zhang, J Y; Zeise, M L; Wang, R Y

    1994-01-01

    The techniques of extracellular single cell recording and microiontophoresis were used to study the effect of 5-HT3 receptor agonists on glutamate-activated firing of CA1 hippocampal pyramidal cells. Iontophoretic application of 5-HT3 receptor agonists 2-methyl-5-HT and SR 57227A produced a current (dose)-dependent suppression of the firing of CA1 pyramidal cells; SR 57227A was more effective than 2-methyl-5-HT. The suppressant action of 2-methyl-5-HT and SR 57227A had a slow onset and showed little or no desensitization. This effect was markedly attenuated or completely blocked by the 5-HT3 receptor antagonist BRL 46470A but not by the nonspecific 5-HT1 and 5-HT2 receptor antagonist metergoline or by the 5-HT1A antagonist WAY 100478. Intravenous administration of SR 57227A was effective in reducing the firing rate of CA1 pyramidal cells and this effect was prevented by BRL 46470A administered either i.v. or iontophoretically. Iontophoresis of 2-methyl-5-HT also diminished CA1 postsynaptic field potentials evoked by electrical stimulation of the Schaffer collaterals. Again, BRL 46470A but not metergoline prevented the suppressant action of 2-methyl-5-HT. Taken together, our results indicate that activation of 5-HT3-like receptors in the hippocampal CA1 region effectively reduces the efficacy of glutamatergic neurotransmission. PMID:7984287

  19. Towards green electroluminescence of semipolar InGaN-MQWs on GaN pyramids

    InGaN-structures have attracted much interest due to their properties which allow the development of optoelectronic devices such as light emitting diodes (LEDs) and laser diodes. Recently, blue and green InGaN-LEDs are available, but the so-called quantum-confined Stark effect (QCSE) reduces the emission efficiency of these devices by bowing of the band structure. To lower the QCSE, hexagonal Si-doped GaN-pyramids were deposited, providing semipolar sidewalls tilted 62 with respect to the GaN c-plane. These planes are used for the deposition of InGaN-multiple quantum wells (MQWs). The whole structure is fabricated by low-pressure metal-organic vapor-phase epitaxy (MOVPE). Next to the structural characterization of the samples by scanning electron microscopy, photoluminescence techniques are used to reveal the optical properties. Besides these optical investigation of the Indium distribution on the pyramidal structures, p-i-n junctions are formed by placing a hole injection coating on top of the pyramids. Contact structures were developed to allow electrical injection and the examination of electroluminescence.

  20. Suppressive Effects of Resveratrol Treatment on The Intrinsic Evoked Excitability of CA1 Pyramidal Neurons

    Gholamhossein Meftahi

    2015-10-01

    Full Text Available Objective: Resveratrol, a phytoalexin, has a wide range of desirable biological actions. Despite a growing body of evidence indicating that resveratrol induces changes in neuronal function, little effort, if any, has been made to investigate the cellular effect of resveratrol treatment on intrinsic neuronal properties. Materials and Methods: This experimental study was performed to examine the acute effects of resveratrol (100 μM on the intrinsic evoked responses of rat Cornu Ammonis (CA1 pyramidal neurons in brain slices, using whole cell patch clamp recording under current clamp conditions. Results: Findings showed that resveratrol treatment caused dramatic changes in evoked responses of pyramidal neurons. Its treatment induced a significant (P<0.05 increase in the after hyperpolarization amplitude of the first evoked action potential. Resveratrol-treated cells displayed a significantly broader action potential (AP when compared with either control or vehicle-treated groups. In addition, the mean instantaneous firing frequency between the first two action potentials was significantly lower in resveratrol-treated neurons. It also caused a significant reduction in the time to maximum decay of AP. The rheobase current and the utilization time were both significantly greater following resveratrol treatment. Neurons exhibited a significantly depolarized voltage threshold when exposed to resveratrol. Conclusion: Results provide direct electrophysiological evidence for the inhibitory effects of resveratrol on pyramidal neurons, at least in part, by reducing the evoked neural activity.

  1. Comparative morphology of three types of projection-identified pyramidal neurons in the superficial layers of cat visual cortex.

    Matsubara, J A; Chase, R; Thejomayen, M

    1996-02-26

    The morphology and dendritic organization of corticocortical neurons in the superficial layers of area 18 that project to area 17 were studied by intracellular injection of lucifer yellow in the fixed-slice preparation. This corticocortical population contains primarily standard pyramidal cells, but occasional nonpyramidal, modified, fusiform, star, and inverted pyramidal cells were also seen. All cell types were present throughout layer 2 and in the upper and middle parts of layer 3. Standard pyramidal cells were found exclusively in lower layer 3. The mean somatic area of the area 17 projecting neurons was 251 microns 2. The width of basal dendritic fields was correlated to cell size for standard pyramidal cells but not for the other cell types. Next, the morphology and dendritic organization of the area 17 projecting neurons were compared to the pyramidal cells of the local horizontal patch networks and of the callosal system. The depth profile of the area 17 projecting and callosal pyramidal groups was virtually identical, peaking at 400 microns from the pial surface, whereas the local patch pyramidal group peaked at 281 microns. The local patch, area 17 projecting, and callosal pyramidal cells displayed increasingly larger mean somatic areas and basilar dendritic field width measurements. The number of basal dendritic branch points was greatest for callosal cells, and it was indistinguishable between local patch and area 17 projecting neurons. In the tangential plane, circular dendritic fields were observed on all callosal cells, but they were found on only approximately half of the local patch and area 17 projecting neurons. The remaining local patch and area 17 projecting neurons displayed mediolaterally and anteroposteriorly elongated basal dendritic fields, respectively. PMID:8866848

  2. Restoring the Lost Fishery: An Environmental History of Northern Nevada's Pyramid Lake and Lower Truckee River Fishery

    Bolingbroke, David

    2014-01-01

    This thesis focuses on fisheries managers’ efforts to restore native cutthroats to northern Nevada’s Pyramid Lake for recreation, and the Paiutes’ battle to preserve them as a means of livelihood. Their efforts to reconstruct the fishery revealed the implausibility of environmental restoration, but more importantly underlined the motivations necessary to attempt it. Chapter 2 describes how the Pyramid Lake Lahontan cutthroat— historically an important subsistence resource for Northern Paiu...

  3. Association of Rgs7/Gβ5 complexes with Girk channels and GABAB receptors in hippocampal CA1 pyramidal neurons.

    Fajardo-Serrano, Ana; Wydeven, Nicole; Young, Daniele; Watanabe, Masahiko; Shigemoto, Ryuichi; Martemyanov, Kirill A; Wickman, Kevin; Luján, Rafael

    2013-12-01

    In the hippocampus, signaling through G protein-coupled receptors is modulated by Regulators of G protein signaling (Rgs) proteins, which act to stimulate the rate of GTP hydrolysis, and consequently, G protein inactivation. The R7-Rgs subfamily selectively deactivates the G(i/o)-class of Gα subunits that mediate the action of several GPCRs. Here, we used co-immunoprecipitation, electrophysiology and immunoelectron microscopy techniques to investigate the formation of macromolecular complexes and spatial relationship of Rgs7/Gβ5 complexes and its prototypical signaling partners, the GABAB receptor and Girk channel. Co-expression of recombinant GABAB receptors and Girk channels in combination with co-immunoprecipitation experiments established that the Rgs7/Gβ5 forms complexes with GABAB receptors or Girk channels. Using electrophysiological experiments, we found that GABAB -Girk current deactivation kinetics was markedly faster in cells coexpressing Rgs7/Gβ5. At the electron microscopic level, immunolabeling for Rgs7 and Gβ5 proteins was found primarily in the dendritic layers of the hippocampus and showed similar distribution patterns. Immunoreactivity was mostly localized along the extrasynaptic plasma membrane of dendritic shafts and spines of pyramidal cells and, to a lesser extent, to that of presynaptic terminals. Quantitative analysis of immunogold particles for Rgs7 and Gβ5 revealed an enrichment of the two proteins around excitatory synapses on dendritic spines, virtually identical to that of Girk2 and GABAB1 . These data support the existence of macromolecular complexes composed of GABAB receptor-G protein-Rgs7-Girk channels in which Rgs7 and Gβ5 proteins may preferentialy modulate GABAB receptor signaling through the deactivation of Girk channels on dendritic spines. In contrast, Rgs7 and Girk2 were associated but mainly segregated from GABAB1 in dendritic shafts, where Rgs7/Gβ5 signaling complexes might modulate Girk-dependent signaling via a

  4. Transient Receptor Potential Vanilloid 4 Inhibits γ-Aminobutyric Acid-Activated Current in Hippocampal Pyramidal Neurons

    Hong, Zhiwen; Tian, Yujing; Qi, Mengwen; Li, Yingchun; Du, Yimei; Chen, Lei; Liu, Wentao; Chen, Ling

    2016-01-01

    The balance between excitatory and inhibitory neurotransmitter systems is crucial for the modulation of neuronal excitability in the central nervous system (CNS). The activation of transient receptor potential vanilloid 4 (TRPV4) is reported to enhance the response of hippocampal glutamate receptors, but whether the inhibitory neurotransmitter system can be regulated by TRPV4 remains unknown. γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the CNS. Here, we show that application of transient receptor potential vanilloid 4 (TRPV4) synthetic (GSK1016790A or 4α-PDD) or endogenous agonist (5,6-EET) inhibited GABA-activated current (IGABA) in hippocampal CA1 pyramidal neurons, which was blocked by specific antagonists of TRPV4 and of GABAA receptors. GSK1016790A increased the phosphorylated AMP-activated protein kinase (p-AMPK) and decreased the phosphorylated protein kinase B (p-Akt) protein levels, which was attenuated by removing extracellular calcium or by a calcium/calmodulin-dependent protein kinase kinase-β antagonist. GSK1016790A-induced decrease of p-Akt protein level was sensitive to an AMPK antagonist. GSK1016790A-inhibited IGABA was blocked by an AMPK antagonist or a phosphatidyl inositol 3 kinase (PI3K) agonist. GSK1016790A-induced inhibition of IGABA was also significantly attenuated by a protein kinase C (PKC) antagonist but was unaffected by protein kinase A or calcium/calmodulin-dependent protein kinase II antagonist. We conclude that activation of TRPV4 inhibits GABAA receptor, which may be mediated by activation of AMPK and subsequent down-regulation of PI3K/Akt signaling and activation of PKC signaling. Inhibition of GABAA receptors may account for the neuronal hyperexcitability caused by TRPV4 activation.

  5. Activation of CRH receptor type 1 expressed on glutamatergic neurons increases excitability of CA1 pyramidal neurons by the modulation of voltage-gated ion channels

    Stephan eKratzer

    2013-07-01

    Full Text Available Corticotropin-releasing hormone (CRH plays an important role in a substantial number of patients with stress-related mental disorders, such as anxiety disorders and depression. CRH has been shown to increase neuronal excitability in the hippocampus, but the underlying mechanisms are poorly understood. The effects of CRH on neuronal excitability were investigated in acute hippocampal brain slices. Population spikes (PS and field excitatory postsynaptic potentials (fEPSP were evoked by stimulating Schaffer-collaterals and recorded simultaneously from the somatic and dendritic region of CA1 pyramidal neurons. CRH was found to increase PS amplitudes (mean  Standard error of the mean; 231.8  31.2% of control; n=10 while neither affecting fEPSPs (104.3 ± 4.2%; n=10 nor long-term potentiation (LTP. However, when Schaffer-collaterals were excited via action potentials (APs generated by stimulation of CA3 pyramidal neurons, CRH increased fEPSP amplitudes (119.8 ± 3.6%; n=8 and the magnitude of LTP in the CA1 region. Experiments in slices from transgenic mice revealed that the effect on PS amplitude is mediated exclusively by CRH receptor 1 (CRHR1 expressed on glutamatergic neurons. The effects of CRH on PS were dependent on phosphatase-2B, L- and T-type calcium channels and voltage-gated potassium channels but independent on intracellular Ca2+-elevation. In patch-clamp experiments, CRH increased the frequency and decay times of APs and decreased currents through A-type and delayed-rectifier potassium channels. These results suggest that CRH does not affect synaptic transmission per se, but modulates voltage-gated ion currents important for the generation of APs and hence elevates by this route overall neuronal activity.

  6. Interaction between neuropeptide Y (NPY) and brain-derived neurotrophic factor in NPY-mediated neuroprotection against excitotoxicity

    Xapelli, S; Bernardino, L; Ferreira, R;

    2008-01-01

    -day-old C57BL/6 mice, to 8 microm AMPA, for 24 h, induced degeneration of CA1 and CA3 pyramidal cells, as measured by cellular uptake of propidium iodide (PI). A significant neuroprotection, with a reduction of PI uptake in CA1 and CA3 pyramidal cell layers, was observed after incubation with a Y(2...... up-regulation of neuronal TrkB immunoreactivity, as well as the presence of BDNF-immunoreactive microglial cells at sites of injury. Thus, an increase of AMPA-receptor mediated neurodegeneration, in the mouse hippocampus, was prevented by neuroprotective pathways activated by NPY receptors (Y(1) and...

  7. A simulation study on the effects of dendritic morphology on layer V PFC pyramidal cell firing behavior

    Maria Psarrou

    2014-03-01

    Full Text Available The majority of neuronal cells found in the cerebral cortex are pyramidal neurons. Their function has been associated with higher cognitive and emotional functions. Pyramidal neurons have a characteristic structure, consisting of a triangular shaped soma whereon descend two extended and complex dendritic trees, and a long bifurcated axon. All the morphological components of the pyramidal neurons exhibit significant variability across different brain areas and layers. Pyramidal cells receive numerous synaptic inputs along their structure, integration of which in space and in time generates local dendritic spikes that shape their firing pattern. In addition, synaptic integration is influenced by voltage-gated and ion channels, which are expressed in a large repertoire by pyramidal neurons. Electrophysiological categories of pyramidal cells can be established, based on the action potential frequency, generated from a fixed somatic stimulus: (1 cells that fire repetitive action potentials (Regular Spiking – RS, (2 cells that fire clusters of 2 – 5 action potentials with short ISIs (Intrinsic Bursting – IB, and (3 cells that fire in repetitive clusters of 2 – 5 action potentials with short ISIs (Repetitive Oscillatory Bursts – ROB. In vitro and in silico scientific studies, correlate the firing patterns of the pyramidal neurons to their morphological features. This study provides a quantitatively analysis via compartmental neuronal modelling of the effects of dendritic morphology and distribution and concentration of ionic mechanisms, along the basal and/or apical dendrites on the firing behavior of a 112-set of layer V rat PFC pyramidal cells. We focus on how particular morphological and passive features of the dendritic trees shape the neuronal firing patterns. Our results suggest that specific morphological parameters (such as total length, volume and branch number can discriminate the cells as RS or IB, regardless of what is the

  8. Recursive Pyramid Algorithm-Based Discrete Wavelet Transform for Reactive Power Measurement in Smart Meters

    Atiq, Mahin K.; Waleed Ejaz; Najam ul Hasan; Hyung Seok Kim

    2013-01-01

    Measurement of the active, reactive, and apparent power is one of the most fundamental tasks of smart meters in energy systems. Recently, a number of studies have employed the discrete wavelet transform (DWT) for power measurement in smart meters. The most common way to implement DWT is the pyramid algorithm; however, this is not feasible for practical DWT computation because it requires either a log N cascaded filter or O (N) word size memory storage for an input signal of the N-point. Both ...

  9. Image segmentation of pyramid style identifier based on Support Vector Machine for colorectal endoscopic images.

    Okamoto, Takumi; Koide, Tetsushi; Sugi, Koki; Shimizu, Tatsuya; Anh-Tuan Hoang; Tamaki, Toru; Raytchev, Bisser; Kaneda, Kazufumi; Kominami, Yoko; Yoshida, Shigeto; Mieno, Hiroshi; Tanaka, Shinji

    2015-08-01

    With the increase of colorectal cancer patients in recent years, the needs of quantitative evaluation of colorectal cancer are increased, and the computer-aided diagnosis (CAD) system which supports doctor's diagnosis is essential. In this paper, a hardware design of type identification module in CAD system for colorectal endoscopic images with narrow band imaging (NBI) magnification is proposed for real-time processing of full high definition image (1920 × 1080 pixel). A pyramid style image segmentation with SVMs for multi-size scan windows, which can be implemented on an FPGA with small circuit area and achieve high accuracy, is proposed for actual complex colorectal endoscopic images. PMID:26736922

  10. Altered intrinsic excitability of hippocampal CA1 pyramidal neurons in aged PDAPP mice

    Francesco Tamagnini

    2015-10-01

    These data show that Aβ-overexpression in aged mice altered the capacitance, the neuronal firing and the AP waveform of CA1 pyramidal neurons. Some of these findings are consistent with previous work on younger PDAPP, they also show important differences that can be potentially ascribed to the interaction between amyloidopathy and ageing. Such a change of IE properties over time underlies that the increased incidence of seizure observed in AD patients might rely on different mechanistic pathways during progression of the disease.

  11. Binary TLBO algorithm assisted for designing plasmonic nano bi-pyramids-based absorption coefficient

    Akhlaghi, Majid; Emami, Farzin; Nozhat, Najmeh

    2014-07-01

    A new efficient binary optimization method based on Teaching-Learning-Based Optimization (TLBO) algorithm is proposed to design an array of plasmonic nano bi-pyramids in order to achieve maximum absorption coefficient spectrum. In binary TLBO, a group of learners consisting of a matrix with binary entries controls the presence ('1') or the absence ('0') of nanoparticles in the array. Simulation results show that absorption coefficient strongly depends on the localized position of plasmonic nanoparticles. Non-periodic structures have more appropriate response in term of absorption coefficient. This approach is useful in optical applications such as solar cells and plasmonic nano antenna.

  12. New evidence of an "old" iconographic feature from the Teti pyramid cemetery

    Maříková Vlčková, Petra

    Prague : Institute of Archaeology of the Academy of Sciences of the Czech Republic, Prague, 2009 - (Maříková Vlčková, P.; Mynářová, J.; Tomášek, M.), s. 47-57 ISBN 978-80-87365-18-2; ISBN 978-80-7308-279-6 R&D Projects: GA AV ČR IAA800020804 Institutional research plan: CEZ:AV0Z80020508 Keywords : egyptology * Old Kingdom * Teti pyramid cemetery Subject RIV: AC - Archeology, Anthropology, Ethnology

  13. MyPyramid food intake pattern modeling for the Dietary Guidelines Advisory Committee.

    Britten, Patricia; Lyon, Joan; Weaver, Connie M; Kris-Etherton, Penny M; Nicklas, Theresa A; Weber, Jennifer A; Davis, Carole A

    2006-01-01

    Modeling analyses using the MyPyramid intake patterns were conducted in collaboration with the 2005 Dietary Guidelines Advisory Committee in response to their research questions and to determine likely effects of possible recommendations on overall dietary adequacy. Scenarios modeled included the feasibility of using the food patterns for lacto-ovo-vegetarian diets, of varying fat levels within the patterns, and of increasing dietary flexibility through food group substitutions. Food pattern modeling was a useful tool to identify possible impacts on diet quality of potential Dietary Guidelines recommendations. Modeling analyses can help researchers explore the overall effect of specific dietary recommendations on intake patterns. PMID:17116592

  14. Pyramid Capitalism

    Diwan, Ishac; Keefer, Philip; Schiffbauer, Marc

    2015-01-01

    This paper uses an original database of 469 politically connected firms under the Mubarak regime in Egypt to explore the economic effects of close state-business relations. Previous research has shown that political connections are lucrative. The paper addresses several questions raised by this research. Do connected firms receive favorable regulatory treatment? They do: connected firms ar...

  15. Complex Mediation

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other ha...

  16. Specialized Mediation.

    Hammond, Carol; And Others

    1992-01-01

    Six articles discuss librarians as mediators in special circumstances. Highlights include the reference librarian and the information paraprofessional; effective reference mediation for nontraditional public library users, including mentally impaired patrons and illiterate adults; the academic librarian's role in the education process; and…

  17. Surgical strategy for malignant gliomas involving pyramidal tracts guided by functional neuronavigation and 5-ALA fluorescence navigation

    For patients with malignant glioma invading pyramidal tracts, maximal resections are difficult to accomplish while preserving their motor function. We used tractography-integrated functional neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence-guided resection for removal of malignant gliomas involving pyramidal tract. In this study, we analyzed postoperative motor function and extent of resection in a series of patients who underwent surgery in our department. Ten patients with malignant glioma invading pyramidal tracts underwent radical surgery. To preserve pyramidal tracts, we developed a functional neuronavigation-guided fence-post procedure to avoid the problem of brain shift, a disadvantage of the existing neuronavigation systems. Furthermore we have achieved precise resection of tumors using 5-ALA fluorescence navigation. Intraoperatively, tumor fluorescence was visualized using a modified operating microscope. All fluorescing tumor tissue was resected. Motor function was preserved after appropriate tumor resection in all cases. Postoperatively, improvement of motor weakness was observed in seven patients, whereas transient mild motor weakness occurred in two patients. Gross total removals were accomplished in seven patients, and subtotal removal was accomplished in one patient, and partial removal was accomplished in two patients. Combined use of tractography-integrated functional neuronavigation and 5-ALA fluorescence-guided resection contributes to maximal safe resection of malignant gliomas with pyramidal tract involvement. (author)

  18. Highly anisotropic slip-behavior of pyramidal I 〈c+a〉 dislocations in hexagonal close-packed magnesium

    In hexagonal-closed-pack (HCP) metals, slip of 〈c+a〉 dislocations on pyramidal planes is considered to be the most difficult slip mode that controls the overall plastic behavior. Nevertheless, pyramidal 〈c+a〉 slip is a requisite for accommodation of c-axis plastic deformation. In the present study, glissile pyramidal 〈c+a〉 dislocations with different characters gliding on type I pyramidal planes, informed by direct atomistic simulations, are reproduced and studied in HCP magnesium single crystals. The Peierls stresses for these dislocations are quantitatively evaluated via molecular dynamics simulations under pure shear loading. A high anisotropy in the Peierls stress is observed for different dislocation characters, with the near-screw having the lowest Peierls stress, and the near-edge dislocations having the highest stress. Local shuffling is also found to significantly reduce the Peierls stress of near-edge dislocations. These quantifications of pyramidal 〈c+a〉 slip provide better understanding of plastic deformation in HCP metals, and also provide necessary inputs for meso-scale dislocation models such as discrete dislocation dynamics simulations and crystal plasticity simulations

  19. Recombinant Adeno-Associated Virus-Mediated microRNA Delivery into the Postnatal Mouse Brain Reveals a Role for miR-134 in Dendritogenesis in Vivo

    Christensen, Mette; Larsen, Lars A; Kauppinen, Sakari; Schratt, Gerhard

    2010-01-01

    delivery of microRNAs in vivo by use of recombinant adeno-associated virus (rAAV). rAAV-mediated overexpression of miR-134 in neurons of the postnatal mouse brain provided evidence for a negative role of miR-134 in dendritic arborization of cortical layer V pyramidal neurons in vivo, thereby confirming...

  20. The offset-midpoint traveltime pyramid in 3D transversely isotropic media with a horizontal symmetry axis

    Hao, Qi

    2014-12-30

    Analytic representation of the offset-midpoint traveltime equation for anisotropy is very important for prestack Kirchhoff migration and velocity inversion in anisotropic media. For transversely isotropic media with a vertical symmetry axis, the offset-midpoint traveltime resembles the shape of a Cheops’ pyramid. This is also valid for homogeneous 3D transversely isotropic media with a horizontal symmetry axis (HTI). We extended the offset-midpoint traveltime pyramid to the case of homogeneous 3D HTI. Under the assumption of weak anellipticity of HTI media, we derived an analytic representation of the P-wave traveltime equation and used Shanks transformation to improve the accuracy of horizontal and vertical slownesses. The traveltime pyramid was derived in the depth and time domains. Numerical examples confirmed the accuracy of the proposed approximation for the traveltime function in 3D HTI media.

  1. Characterization of the porcine FBX07 gene: the first step towards generation of a pig model for Parkinsonian pyramidal syndrome

    Larsen, Knud; Bendixen, Christian

    2012-01-01

    Parkinsonian pyramidal syndrome, also named pallido-pyramidal syndrome (PKPS), is the combination of early-onset progressive Parkinsonism with pyramidal tract signs. FBXO7, an F-box protein, is a component of modular E3 ubiquitin protein ligases called SCFs (SKP1, cullin, F-box proteins), which...... functions in phosphorylation-dependent ubiquitination. FBXO7 mutations cause autosomal recessive, early-onset PKPS. Here we report the molecular cloning and characterization of two isoforms of FBXO7 cDNA from pigs. The encoded FBXO7 protein displays a very high homology to human FBXO7 with an amino acid......). Using a radiation hybrid map the FBXO7 gene was mapped to pig chromosome 5. Real-time quantitative RT-PCR analysis revealed that FBXO7 mRNA is differentially expressed in many tissues and organs, and that FBXO7 transcript can be detected early in embryo development....

  2. Template-Stripped Multifunctional Wedge and Pyramid Arrays for Magnetic Nanofocusing and Optical Sensing.

    Kumar, Shailabh; Johnson, Timothy W; Wood, Christopher K; Qu, Tao; Wittenberg, Nathan J; Otto, Lauren M; Shaver, Jonah; Long, Nicholas J; Victora, Randall H; Edel, Joshua B; Oh, Sang-Hyun

    2016-04-13

    We present large-scale reproducible fabrication of multifunctional ultrasharp metallic structures on planar substrates with capabilities including magnetic field nanofocusing and plasmonic sensing. Objects with sharp tips such as wedges and pyramids made with noble metals have been extensively used for enhancing local electric fields via the lightning-rod effect or plasmonic nanofocusing. However, analogous nanofocusing of magnetic fields using sharp tips made with magnetic materials has not been widely realized. Reproducible fabrication of sharp tips with magnetic as well as noble metal layers on planar substrates can enable straightforward application of their material and shape-derived functionalities. We use a template-stripping method to produce plasmonic-shell-coated nickel wedge and pyramid arrays at the wafer-scale with tip radius of curvature close to 10 nm. We further explore the magnetic nanofocusing capabilities of these ultrasharp substrates, deriving analytical formulas and comparing the results with computer simulations. These structures exhibit nanoscale spatial control over the trapping of magnetic microbeads and nanoparticles in solution. Additionally, enhanced optical sensing of analytes by these plasmonic-shell-coated substrates is demonstrated using surface-enhanced Raman spectroscopy. These methods can guide the design and fabrication of novel devices with applications including nanoparticle manipulation, biosensing, and magnetoplasmonics. PMID:26837912

  3. Recursive Pyramid Algorithm-Based Discrete Wavelet Transform for Reactive Power Measurement in Smart Meters

    Mahin K. Atiq

    2013-09-01

    Full Text Available Measurement of the active, reactive, and apparent power is one of the most fundamental tasks of smart meters in energy systems. Recently, a number of studies have employed the discrete wavelet transform (DWT for power measurement in smart meters. The most common way to implement DWT is the pyramid algorithm; however, this is not feasible for practical DWT computation because it requires either a log N cascaded filter or O (N word size memory storage for an input signal of the N-point. Both solutions are too expensive for practical applications of smart meters. It is proposed that the recursive pyramid algorithm is more suitable for smart meter implementation because it requires only word size storage of L × Log (N-L, where L is the length of filter. We also investigated the effect of varying different system parameters, such as the sampling rate, dc offset, phase offset, linearity error in current and voltage sensors, analog to digital converter resolution, and number of harmonics in a non-sinusoidal system, on the reactive energy measurement using DWT. The error analysis is depicted in the form of the absolute difference between the measured and the true value of the reactive energy.

  4. A Generalized Pyramid Matching Kernel for Human Action Recognition in Realistic Videos

    Wenjun Zhang

    2013-10-01

    Full Text Available Human action recognition is an increasingly important research topic in the fields of video sensing, analysis and understanding. Caused by unconstrained sensing conditions, there exist large intra-class variations and inter-class ambiguities in realistic videos, which hinder the improvement of recognition performance for recent vision-based action recognition systems. In this paper, we propose a generalized pyramid matching kernel (GPMK for recognizing human actions in realistic videos, based on a multi-channel “bag of words” representation constructed from local spatial-temporal features of video clips. As an extension to the spatial-temporal pyramid matching (STPM kernel, the GPMK leverages heterogeneous visual cues in multiple feature descriptor types and spatial-temporal grid granularity levels, to build a valid similarity metric between two video clips for kernel-based classification. Instead of the predefined and fixed weights used in STPM, we present a simple, yet effective, method to compute adaptive channel weights of GPMK based on the kernel target alignment from training data. It incorporates prior knowledge and the data-driven information of different channels in a principled way. The experimental results on three challenging video datasets (i.e., Hollywood2, Youtube and HMDB51 validate the superiority of our GPMK w.r.t. the traditional STPM kernel for realistic human action recognition and outperform the state-of-the-art results in the literature.

  5. Color Face Recognition Based on Steerable Pyramid Transform and Extreme Learning Machines

    Ayşegül Uçar

    2014-01-01

    Full Text Available This paper presents a novel color face recognition algorithm by means of fusing color and local information. The proposed algorithm fuses the multiple features derived from different color spaces. Multiorientation and multiscale information relating to the color face features are extracted by applying Steerable Pyramid Transform (SPT to the local face regions. In this paper, the new three hybrid color spaces, YSCr, ZnSCr, and BnSCr, are firstly constructed using the Cb and Cr component images of the YCbCr color space, the S color component of the HSV color spaces, and the Zn and Bn color components of the normalized XYZ color space. Secondly, the color component face images are partitioned into the local patches. Thirdly, SPT is applied to local face regions and some statistical features are extracted. Fourthly, all features are fused according to decision fusion frame and the combinations of Extreme Learning Machines classifiers are applied to achieve color face recognition with fast and high correctness. The experiments show that the proposed Local Color Steerable Pyramid Transform (LCSPT face recognition algorithm improves seriously face recognition performance by using the new color spaces compared to the conventional and some hybrid ones. Furthermore, it achieves faster recognition compared with state-of-the-art studies.

  6. Novel Cross-Slip Mechanism of Pyramidal Screw Dislocations in Magnesium

    Itakura, Mitsuhiro; Kaburaki, Hideo; Yamaguchi, Masatake; Tsuru, Tomohito

    2016-06-01

    Compared to cubic metals, whose primary slip mode includes twelve equivalent systems, the lower crystalline symmetry of hexagonal close-packed metals results in a reduced number of equivalent primary slips and anisotropy in plasticity, leading to brittleness at the ambient temperature. At higher temperatures, the ductility of hexagonal close-packed metals improves owing to the activation of secondary ⟨c +a ⟩ pyramidal slip systems. Thus, understanding the fundamental properties of corresponding dislocations is essential for the improvement of ductility at the ambient temperature. Here, we present the results of large-scale ab initio calculations for ⟨c +a ⟩ pyramidal screw dislocations in magnesium and show that their slip behavior is a stark counterexample to the conventional wisdom that a slip plane is determined by the stacking fault plane of dislocations. A stacking fault between dissociated partial dislocations can assume a nonplanar shape with a negligible energy cost and can migrate normal to its plane by a local shuffling of atoms. Partial dislocations dissociated on a {2 1 ¯ 1 ¯ 2 } plane "slither" in the {01 1 ¯1 } plane, dragging the stacking fault with them in response to an applied shear stress. This finding resolves the apparent discrepancy that both {2 1 ¯1 ¯2 } and {01 1 ¯1 } slip traces are observed in experiments while ab initio calculations indicate that dislocations preferably dissociate in the {2 1 ¯1 ¯2 } planes.

  7. Biofilm exopolymers control microbialite formation at thermal springs discharging into the alkaline Pyramid Lake, Nevada, USA

    Arp, Gernot; Thiel, Volker; Reimer, Andreas; Michaelis, Walter; Reitner, Joachim

    1999-07-01

    Calcium carbonate precipitation and microbialite formation at highly supersaturated mixing zones of thermal spring waters and alkaline lake water have been investigated at Pyramid Lake, Nevada. Without precipitation, pure mixing should lead to a nearly 100-fold supersaturation at 40°C. Physicochemical precipitation is modified or even inhibited by the properties of biofilms, dependent on the extent of biofilm development and the current precipitation rate. Mucus substances (extracellular polymeric substances, EPS, e.g., of cyanobacteria) serve as effective Ca 2+-buffers, thus preventing seed crystal nucleation even in a highly supersaturated macroenvironment. Carbonate is then preferentially precipitated in mucus-free areas such as empty diatom tests or voids. After the buffer capacity of the EPS is surpassed, precipitation is observed at the margins of mucus areas. Hydrocarbon biomarkers extracted from (1) a calcifying Phormidium-biofilm, (2) the stromatolitic carbonate below, and (3) a fossil `tufa' of the Pleistocene pinnacles, indicate that the cyanobacterial primary producers have been subject to significant temporal changes in their species distribution. Accordingly, the species composition of cyanobacterial biofilms does not appear to be relevant for the formation of microbial carbonates in Pyramid Lake. The results demonstrate the crucial influence of mucus substances on carbonate precipitation in highly supersaturated natural environments.

  8. On Applications of Pyramid Doubly Joint Bilateral Filtering in Dense Disparity Propagation

    Abadpour, Arash

    2014-06-01

    Stereopsis is the basis for numerous tasks in machine vision, robotics, and 3D data acquisition and processing. In order for the subsequent algorithms to function properly, it is important that an affordable method exists that, given a pair of images taken by two cameras, can produce a representation of disparity or depth. This topic has been an active research field since the early days of work on image processing problems and rich literature is available on the topic. Joint bilateral filters have been recently proposed as a more affordable alternative to anisotropic diffusion. This class of image operators utilizes correlation in multiple modalities for purposes such as interpolation and upscaling. In this work, we develop the application of bilateral filtering for converting a large set of sparse disparity measurements into a dense disparity map. This paper develops novel methods for utilizing bilateral filters in joint, pyramid, and doubly joint settings, for purposes including missing value estimation and upscaling. We utilize images of natural and man-made scenes in order to exhibit the possibilities offered through the use of pyramid doubly joint bilateral filtering for stereopsis.

  9. Power to the poor: sustainable energy at the base of the pyramid

    Zarsky, Lyuba [Monterey Institute of International Studies, Monterey, CA (United States); Wilson, Emma

    2009-11-15

    Four billion people – over half of humanity – live on less than US$2 a day, effectively forming the bottom of the world economic pyramid. This majority may have minimal access to cash but they need, and will pay for, essential goods and services – including energy. 'The fortune at the bottom of the pyramid,' a 2002 article, argues that if global corporations target this 4 billion, they can reduce poverty and make profit. That the private sector is already playing a key role in meeting development challenges, such as energy poverty, is increasingly recognised. 'Inclusive' and 'shared value' business approaches have begun to multiply. International energy companies, including hydrocarbon and renewable energy producers, can (and do) facilitate local access to energy in poorer regions of the world. To reach the poorest and to effectively contribute to sustainable local development in the long term, however, standard business models need to be modified, and alliances forged with government, local enterprises, donors and NGOs. Smaller local firms are often the ones that reach the poor more effectively. They just need the right support.

  10. Thalamocortical input onto layer 5 pyramidal neurons measured using quantitative large-scale array tomography

    Jong-Cheol eRah

    2013-11-01

    Full Text Available The subcellular locations of synapses on pyramidal neurons strongly influences dendritic integration and synaptic plasticity. Despite this, there is little quantitative data on spatial distributions of specific types of synaptic input. Here we use array tomography (AT, a high-resolution optical microscopy method, to examine thalamocortical (TC input onto layer 5 pyramidal neurons. We first verified the ability of AT to identify synapses using parallel electron microscopic analysis of TC synapses in layer 4. We then use large-scale AT to measure TC synapse distribution on L5 pyramdial neurons in a 1.00 x 0.83 x 0.21 mm^3 volume of mouse somatosensory cortex. We found that TC synapses primarily target basal dendrites in layer 5, but also make a considerable input to proximal apical dendrites in L4, consistent with previous work. Our analysis further suggests that TC inputs are biased towards certain branches and, within branches, synapses show significant clustering with an excess of TC synapse nearest neighbors within 5-15 μm compared to a random distribution. Thus, we show that AT is a sensitive and quantitative method to map specific types of synaptic input on the dendrites of entire neurons. We anticipate that this technique will be of wide utility for mapping functionally-relevant anatomical connectivity in neural circuits.

  11. Spin state transformations of a 3d ion in the pyramidal environment and under lattice distortions

    Spin state (SS) transitions in metal-containing pyramidal complexes that originate from crystallographic distortions are the research subject of this work. The transition elements are considered to be in the 3d6 configuration (Fe2+, Co3+), and they display three different SSs: low-spin (LS,S = 0), intermediate-spin (IS,S = 1) and high-spin (HS,S = 2) states. They have been studied in the frame of the crystal field approximation via the effective nuclear charge Zeff and under oxygen cage distortions. The features of the SS stability have been calculated with/without accounting for spin-orbit coupling. Some critical points at which an accidental degeneracy of the SSs exist have been revealed. Near the critical points, negligible distortions can crucially change the SS. It is demonstrated that the ground SS of the pyramidal MeO5 complex is very sensitive to the symmetry and magnitude of its distortions. SS diagrams in the parameter space 'effective charge'-'distortion magnitude' have been established. It is revealed that the IS state exists as a ground state for all considered distortions with a corresponding choice of Zeff. Jahn-Teller distortions stabilize the IS state in a wide range of Zeff. The orbital-like reorientation of the electron density distribution was observed for the IS state at some threshold magnitude of Jahn-Teller distortions

  12. The spin state evolution of a 3d-ion in the pyramidal complex

    The spin state evolution of a 3d-ion, which is located in the pyramidal MeO5 environment, has been studied. We consider the transition metal ions with 3d6- (Fe2+, Co3: +), and 3d4-configurations (Mn3+, Cr2+). The transformation of the spin states from S = 0 to S = 1 and S = 2 with varying the metallic ion effective charge Zeff and displacing the oxygen ions was investigated. The spin state stability was examined depending on the magnitude and the symmetry of the ligand distortions. We studied the breathing like distortions, the displacement of the 3d-ion along the Z axis, the Jan-Teller like displacements of MeO4 basic pyramidal plane, and the corrugation like MeO4 plane displacements. It is shown that different distortions create different scenarios of the term behaviors, which correspond to the basic spin states. It is found the spin state of the MeO5 coordination complex with the 3d4-configuration of the metal ion is most sensible to the breathing-like distortions, while the Jan-Teller distortions stabilize the state with S=1 for the 3d6 configuration

  13. Formation of Various Pyramidal Structures on Monocrystalline Silicon Surface and Their Influence on the Solar Cells

    Yangang Han

    2013-01-01

    Full Text Available Texturization is a useful method to enhance the optical absorption of monocrystalline silicon wafers by light-trapping effect in solar cell processing. In present study, a series of textured wafers with various pyramid sizes ranging from 200 nm to 10 μm were fabricated by modified wet-chemical method and characterized. The results show that there is little difference in the reflectance with the pyramid sizes from 1 to 10 μm, which is consistent with the ray-tracing simulation results. However, the light-trapping function of the 200 nm sample below the geometrical optics limit is much weaker. The solar cells fabricated from the 1 μm samples own the highest power conversion efficiency of 18.17% due to a better coverage of metal finger lines than the larger ones, and the 200 nm samples have the lowest efficiency of 10.53%.

  14. Neurofilament-labeled pyramidal neurons and astrocytes are deficient in DNA methylation marks in Alzheimer's disease.

    Phipps, Andrew J; Vickers, James C; Taberlay, Phillippa C; Woodhouse, Adele

    2016-09-01

    There is increasing evidence that epigenetic alterations may play a role in Alzheimer's disease (AD); yet, there is little information regarding epigenetic modifications in specific cell types. We assessed DNA methylation (5-methylcytosine [5mC]) and hydroxymethylation (5-hydroxymethylcytosine [5hmC]) marks specifically in neuronal and glial cell types in the inferior temporal gyrus of human AD cases and age-matched controls. Interestingly, neurofilament (NF)-labeled pyramidal neurons that are vulnerable to AD pathology are deficient in extranuclear 5mC in AD cases compared with controls. We also found that fewer astrocytes exhibited nuclear 5mC and 5hmC marks in AD cases compared with controls. However, there were no alterations in 5mC and 5hmC in disease-resistant calretinin interneurons or microglia in AD, and there was no alteration in the density of 5mC- or 5hmC-labeled nuclei in near-plaque versus plaque-free regions in late-AD cases. 5mC and 5hmC were present in a high proportion of neurofibrillary tangles, suggesting no loss of DNA methylation marks in tangle bearing neurons. We provide evidence that epigenetic dysregulation may be occurring in astrocytes and NF-positive pyramidal neurons in AD. PMID:27459923

  15. Spatial Gene-Expression Gradients Underlie Prominent Heterogeneity of CA1 Pyramidal Neurons.

    Cembrowski, Mark S; Bachman, Julia L; Wang, Lihua; Sugino, Ken; Shields, Brenda C; Spruston, Nelson

    2016-01-20

    Tissue and organ function has been conventionally understood in terms of the interactions among discrete and homogeneous cell types. This approach has proven difficult in neuroscience due to the marked diversity across different neuron classes, but it may be further hampered by prominent within-class variability. Here, we considered a well-defined canonical neuronal population—hippocampal CA1 pyramidal cells (CA1 PCs)—and systematically examined the extent and spatial rules of transcriptional heterogeneity. Using next-generation RNA sequencing, we identified striking variability in CA1 PCs, such that the differences within CA1 along the dorsal-ventral axis rivaled differences across distinct pyramidal neuron classes. This variability emerged from a spectrum of continuous gene-expression gradients, producing a transcriptional profile consistent with a multifarious continuum of cells. This work reveals an unexpected amount of variability within a canonical and narrowly defined neuronal population and suggests that continuous, within-class heterogeneity may be an important feature of neural circuits. PMID:26777276

  16. Downregulation of dendritic HCN channel gating in epilepsy is mediated by altered phosphorylation signaling

    Jung, Sangwook; Bullis, James B.; Lau, Ignatius H.; Jones, Terrance D.; Warner, Lindsay N.; Poolos, Nicholas P

    2010-01-01

    The onset of spontaneous seizures in the pilocarpine model of epilepsy causes a hyperpolarized shift in the voltage-dependent activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channel-mediated current (Ih) in CA1 hippocampal pyramidal neuron dendrites, contributing to neuronal hyperexcitability and possibly to epileptogenesis. However, the specific mechanisms by which spontaneous seizures cause downregulation of HCN channel gating are yet unknown. We asked whether the se...

  17. Shift of the pyramidal tract during resection of the intraaxial brain tumors estimated by intraoperative diffusion-weighted imaging

    The present study evaluated the shift of the pyramidal tract during resection of 17 proximal intraaxial brain tumors. In each case intraoperative diffusion-weighted (iDW) magnetic resonance imaging with a motion-probing gradient applied in the anteroposterior direction was performed using a scanner with a 0.3 T vertical magnetic field. The position of the white matter bundles containing the pyramidal tract was estimated on the coronal images before and after resection of the neoplasm, and both quantitative and directional evaluation of its displacement was done. In all cases iDW imaging provided visualization of the structure of interest. The magnitude of the pyramidal tract displacement due to removal of the neoplasm varied from 0.5 to 8.7 mm (mean 4.4±2.5 mm) on the lesion side and from 0 to 3.6 mm (mean 1.3±1.1 mm) on the normal side (p<0.001). Tumor location in regards to the pyramidal tract was significantly associated with the direction of the pyramidal tract displacement (p<0.05). Outward shift occurred in 10 out of 13 cases of the lateral neoplasms, whereas in all 4 superomedial tumors inward shift was marked. In conclusion, the direction of the pyramidal tract displacement during resection of the proximal intraaxial brain tumors is mainly determined by position of the neoplasm, but can be unpredictable in some cases, which necessitates use of subcortical brain mapping and intraoperative imaging, particularly iDW imaging with updated neuronavigation. (author)

  18. PYRAMIDS AND POPPIES; The 1st SA Infantry Brigade in Libya, France and Flanders 1915-1919

    Noëlle Cowling

    2012-01-01

    Pyramids and Poppies by Peter Digby is a book entirely devoted to the fortunes, and misfortunes, of the 1st South African Brigade during World War One. The Brigade was the first South African force ever to experience combat in Europe or North Africa. As this grants the contingent a distinctive standing in local military history, Pyramids and Poppies is a book which will be of interest, not only to World War One enthusiasts, but to most of warfare's other ardent fans as well.

  19. THE COMPETITIVENESS AND ITS MEASUREMENT BY MEANS OF THE PYRAMID MODEL

    Nagy Tunde Orsolya

    2015-07-01

    Full Text Available The competition itself, the fighting for the scarce resources is as old as the mankind. However, the naming ‘competitiveness’ has been present in the specialized literature since the 1980s. Nowadays, by crescendo of the international competition, concept of the competitiveness has become increasingly important among the decision makers at national economic and corporate levels alike. However, almost everyone means something different by competitiveness, even the researchers dealing with it have not created a uniform definition accepted by everyone. Most of them have worded their competitiveness definition with regard to corporate and national economic levels. The localization appears more pronouncedly in the economic formed and changed by effect of the globalization; economic roles of the regions, sub-regions are increasingly revaluated. This procedure is also mirrored by the competitiveness-themed theoretical and practical researches of the recent years; a significant part of them is aimed at some local levels. Topic of present treatise is the investigation of competitiveness of the regional level, among the local levels. This choice is justified by the fact the European Union decides about disbursement of the financial sources improving the competitiveness, with regard to the regional level NUTS 2. Models dealing with examination of the regional competitiveness can basically be grouped around two basic models. Members of the model family built on the benefits have largely a case study nature while the pyramid model to be presented belongs to the so called input-performance-output models. Basis of the model is the success factors which influence the region’s competitiveness in a long term through metastases. And the success factors determine such basic factors as the research-development; the organizational background of the region’s economy; investments from the outside; infrastructure and human capital; as well as the institutions and

  20. Climate change vulnerabilities- an integrated assessment in Pyramid Lake Paiute Indian Reservation

    Gautam, M. R.; Chief, K.; Wilde, K.; Smith, W.

    2011-12-01

    There are increasing concerns of potential climate change impacts that may place the Truckee River Basin in Nevada under unprecedented stress. We hypothesized that Pyramid Lake, a terminal lake of Truckee River, is prone to climatic as well as non-climatic stressors stemming from cumulative impacts from upstream urban areas and activities. Thus climate change may impair the ability of a major downstream water user, the Pyramid Lake Paiute Tribe (PLPT), to cope and adapt. The conventional approach in assessing vulnerability primarily focuses on hazards or biophysical vulnerabilities, such as water availability, floods, and drought impact. However, we found it inadequate to address the overall vulnerability of the PLPT. Thus in addition to biophysical vulnerabilities, intrinsic and external vulnerabilities were considered such as socio-economic variables (e.g. adaptive capacity) and policy and legal drivers (e.g. water rights). We proposed an elaborate framework for an integrated vulnerability assessment by adapting IPCC framework for vulnerability assessment, the Exposure-Sensitivity-Adaptive Capacity, and applied it to PLPT. Analysis of projected climate change dataset pointed towards increased incidences of floods and droughts and a warming trend over the whole basin with a higher rate at the lower basin in the future. In effort to understand how climatic trends trigger the vulnerability of PLPT, a multi-pronged approach was employed to understand key tribal livelihood assets including an in-depth analysis of the adaptive capacity of PLPT, a climate change survey, and a historical analysis of water conflict and negotiation. Results of the survey identified key natural assets as the lake, endangered fish, rangeland, and wetlands. The framework of a casual-loop diagram was developed in a system dynamic model that incorporated opinions of tribal stakeholders and other experts to evaluate how potential future climate changes might impact the endangered Cui ui fish

  1. The influence of the opening between the heads of the two closest pyramids in textured surface for solar cells and its application on the spectral response

    This study is concerned with the development of a new solar cell prototype in order to improve photovoltaic efficiency. In this model we show that the material can have five and more successive incident-ray absorptions instead of three current, where we changed the direction of the reflected ray, by varying the angle between the two neighbouring pyramids, the incidence angle, the opening between the heads of the two closest pyramids and their height. Thus, with an angle between the two neighbouring pyramids varying between 24 and 12° and an angle of incidence varying between 78 and 84°, the opening between the heads of the two closest pyramids varied respectively from 4.25 to 2.10 μm for a pyramid height of 10 μm. This leads to a substantial increase of the spectral response and the photovoltaic efficiency.

  2. Educational Software for Interactive Training of Students on the Theme "Mutual Intersecting of Pyramids and Prisms in Axonometry"

    Karaibryamov, Samet; Tsareva, Bistra; Zlatanov, Boyan

    2012-01-01

    This work acquaints with the program Sam for interactive computer training of students on the theme "Mutual intersecting of pyramids and prisms in axonometry". The program containing three modules--teacher, student and autopilot--allows for briefest time to teach and study the whole variety of the tasks on this theme. A classification of…

  3. Simple Method for Evaluation of Planum Temporale Pyramidal Neurons Shrinkage in Postmortem Tissue of Alzheimer Disease Patients

    Martina Kutová

    2014-01-01

    Full Text Available We measured the length of the pyramidal neurons in the cortical layer III in four subregions of the planum temporale (transitions into superior temporal gyrus, Heschl’s gyrus, insular cortex, and Sylvian fissure in control group and Alzheimer disease patients. Our hypothesis was that overall length of the pyramidal neurons would be smaller in the Alzheimer disease group compared to controls and also there would be right-left asymmetry in both the control and Alzheimer disease groups. We found pyramidal neuron length asymmetry only in controls—in the transition into the Sylvian fissure—and the rest of the subregions in the control group and Alzheimer disease patients did not show size difference. However, control-Alzheimer disease group pyramidal neuron length comparison revealed (a no length difference in superior temporal gyrus transition area, (b reversal of asymmetry in the insular transition area with left insular transition significantly shorter in the Alzheimer disease group compared to the control group, (c both right and left Heschl’s gyrus transitions significantly shorter in the Alzheimer disease group compared to the control group, and (d right Sylvian fissure transition significantly shorter in the Alzheimer disease group compared to the control group. This neuronal length measurement method could supplement already existing neuropathological criteria for postmortem Alzheimer disease diagnostics.

  4. AUTOJOM, Quadratic Equation Coefficient for Conic Volume, Parallelepipeds, Wedges, Pyramids. JOMREAD, Check of 3-D Geometry Structure from Quadratic Surfaces

    Nature of physical problem solved: AUTOJOM is a computer program that will generate the coefficients of any quadratic equation used to define conic volumes and also the coefficients of the planes needed to define parallelepipeds, wedges, and pyramids. JOMREAD is a computer code to check any 3D geometry composed of and constructed with quadratic surfaces

  5. Regular radon activity concentration and effective dose measurements inside the great pyramid with passive nuclear track detectors.

    Hafez, A F; Bishara, A A; Kotb, M A; Hussein, A S

    2003-08-01

    Radon activity concentrations and equilibrium factors inside the great pyramid of "Cheops" were measured with passive nuclear track detectors. The variation of these concentrations in location was investigated. Seasonal variation of radon activity concentrations with winter maximum and summer minimum were observed inside the pyramid. The 1-y average radon activity concentration ranged from a minimum of 20 to a maximum of 170 Bq m(-3). Results show that the yearly average equilibrium factor between radon and its progeny was assessed as 0.16 and 0.36 inside the pyramid and near entrance, respectively. Moreover, the estimated annual effective dose was 0.05 mSv to tour guides and varied from 0.19 to 0.36 mSv for the pyramid guards; for visitors the average effective dose was 0.15 microSv per visit. These are lower than the 3-10 mSv y(-1) dose limit recommend by ICRP 65. PMID:12938968

  6. Community incidence of pathogen-specific gastroenteritis: reconstructing the surveillance pyramid for seven pathogens in seven European Union member states

    Haagsma, J. A.; Geenen, P. L.; Ethelberg, S.;

    2013-01-01

    By building reconstruction models for a case of gastroenteritis in the general population moving through different steps of the surveillance pyramid we estimated that millions of illnesses occur annually in the European population, leading to thousands of hospitalizations. We used data on the...

  7. Childhood Obesity Study: A Pilot Study of the Effect of the Nutrition Education Program "Color My Pyramid"

    Moore, Jean Burley; Pawloski, Lisa Renee; Goldberg, Patricia; Oh, Kyeung Mi; Stoehr, Ana; Baghi, Heibatollah

    2009-01-01

    The need for successful nutrition interventions is critical as the prevalence of childhood obesity increases. Thus, this pilot project examines the effect of a nutrition education program, "Color My Pyramid", on children's nutrition knowledge, self-care practices, activity levels, and nutrition status. Using a pretest-posttest, quasiexperimental…

  8. The Environmental (Un)sustainability of the Base-of-the-Pyramid (BOP) Philosophy: A Governance Perspective

    F.H. Wijen (Frank)

    2008-01-01

    textabstractThe Base- or Bottom-of-the-Pyramid (BOP) philosophy has rapidly gained currency in business, following seminal articles and books in the popular management literature (Prahalad and Hammond, 2002; Hart and Christensen, 2002; Prahalad, 2005; Hart, 2005). The thrust of the BOP philosophy is

  9. US adolescents and MyPyramid: Associations between fast-food consumption and lower likelihood of meeting recommendations

    The goals of this study were to determine the effect of fast food consumption on adolescents’ food group intakes and likelihood of meeting recommendations outlined in USDA’s MyPyramid Food Guidance System. Two days of 24-hour recall data from 1,956 adolescents 12-19 years of age collected in What W...

  10. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  11. Indoor 22Rn and 222Rn concentration measurements inside the Teotihuacan pyramids using NTD and E-PERM methodologies

    Measurements of 22Rn (Thoron) and 222Rn (Radon) concentrations, inside the Sun and Moon pyramids of Teotihuacan's archeological zone in Mexico, are reported in this work. Two well-established methods, nuclear track detectors (NTDs), using open-close end cups with internal and external detectors of CR-39 polymer, and electret-passive environmental radon monitoring (E-PERM) were used for the measurements. This experiment had two objectives: to obtain better confidence in the 22Rn and 222Rn measurements inside the archeological tunnels, and to compare the data obtained in each one of the two methods. This experiment is specially interesting because of the very peculiar conditions where the measurements are made: high humidity, labyrinths with air currents, but almost constant temperature inside of the pyramid tunnels and galleries, notwithstanding of the temperature changes between the day and the night outside of the pyramid body. The 222Rn concentrations found in both the pyramids were lower than the action level proposed by the ICRP-65. These tunnels are not open to the public, but researchers from the Anthropology Institutions spend part of their time working there, in periods varying from 3 to 5 months

  12. Installation, operation, and maintenance for the pyramidal optics solar system installed at Yacht Cover, Columbia, South Carolina

    1980-01-01

    Information concerning the installation, operation, and maintenance of the pyramidal Solar System for space heating and domestic hot water is presented. Principles of operation, sequence of installation, and procedures for the operation and maintenance of each subsystem making up the solar system are presented. Troubleshooting charts and maintenance schedules are presented.

  13. Reading across My Pyramid, a Nutrition and Health Education Curriculum, Increases the Health Behavior Knowledge of Lower Elementary Students

    Heneman, Karrie; Junge, Sharon K.; Zidenberg-­Cherr, Sheri

    2008-01-01

    Objectives: The purpose of this investigation was to complete a formal evaluation of Reading Across My Pyramid (RAMP), a literacy promoting nutrition and health education curriculum. Methods: To meet this need, a short survey, the "Child Survey," based on topics covered in RAMP lessons was developed and tested for clarity in a group of…

  14. Unusual mortalities of the eastern black rhinoceros (Diceros bicornis michaeli) due to clostridial enterotoxaemia in Ol Jogi Pyramid Sanctuary, Kenya

    Ndeereh, D.; Ouma, B.O.; Gaymer, J.; Mutinda, M.; Gakuya, F.

    2012-01-01

    Nine eastern black rhinoceroses (Diceros bicornis michaeli) developed clinical clostridial enterotoxaemia between May and July 2010 in the Pyramid Black Rhino Sanctuary within the Ol Jogi Conservancy, Laikipia, Kenya. The rhinos presented with a peracute syndrome characterised by severe abdominal pa

  15. First Measurements of Ambient Total Gaseous Mercury (TGM at the EvK2CNR Pyramid Observatory in Nepal

    Gratz L. E.

    2013-04-01

    Full Text Available As part of the Global Mercury Observation System (GMOS project, a global-scale network of ground-based atmospheric monitoring sites is being developed with the objective of expanding the global coverage of atmospheric mercury (Hg measurements and improving our understanding of global atmospheric Hg transport. An important addition to the GMOS monitorng network has been the high altitude EvK2CNR Pyramid Observatory, located at an elevation of 5,050 meters a.s.l. in the eastern Himalaya Mountains of Nepal. Monitoring of total gaseous mercury (TGM using the Tekran 2537A Mercury Vapor Analyzer began at the EvK2CNR Pyramid Observatory in November 2011. From 17 November 2011 to 23 April 2012, the mean concentration of TGM at the Pyramid was 1.2 ng m−3. A range of concentrations from 0.7 to 2.6 ng m−3 has been observed. These are the first reported measurements of atmospheric Hg in Nepal, and currently this is the highest altitude monitoring station for atmospheric Hg in the world. It is anticipated that these high quality measurements, in combination with the other continuous atmospheric measurments being collected at the Pyramid station, will help to further our understanding of Hg concentrations in the free troposphere and the transport of atmospheric Hg on the global scale.

  16. Angular response characteristic of pyramid shape fast neutron dosimeter using CR-39 films

    CR-39 is a highly sensitive etched track detector for neutron monitoring and dosimetry applications but its dose equivalent response is strongly direction dependent with respect to the incident neutrons. This is considered to be a major drawback for their use. In the present study, an attempt has been made to develop a pyramid shaped dosimeter, which consists of polyethylene material of thickness 1 mm with the provision to hold three CR-39 films at an angle of 35 deg. to each other. The response of CR-39 in this configuration under optimum electrochemical etching at elevated temperature have been found nearly angular independent and therefore the dosimeter can be used for neutron monitoring, i.e. personnel as well as area monitoring

  17. A childhood form of Huntington's disease associated with marked pyramidal signs.

    Katafuchi, Y; Fujimoto, T; Ono, E; Kuda, N

    1984-01-01

    The case of a childhood form of Huntington's disease in a 9-year-old boy is reported. The patient had complaints of generalized convulsions from the age of 4, and progressive motor disabilities and mental deterioration from the age of 6. His father had suffered from Huntington's disease for 10 years, and his paternal uncle and aunt, who died at the age of 52, were diagnosed as having this disease. Neurological examination revealed severe mental retardation and marked pyramidal signs. He has no signs or symptoms of involuntary movement, muscular rigidity or ataxia. Axial computed tomography showed marked dilatation of the frontal horns and suggested caudate atrophy. This case is atypical of a childhood form of Huntington's disease because of the lack of muscular rigidity and choreiform movement. But computed tomographic findings correspond to that typically seen in cases of adult Huntington's disease. PMID:6237914

  18. Accumulating pyramid spatial-spectral collaborative coding divergence for hyperspectral anomaly detection

    Sun, Hao; Zou, Huanxin; Zhou, Shilin

    2016-03-01

    Detection of anomalous targets of various sizes in hyperspectral data has received a lot of attention in reconnaissance and surveillance applications. Many anomaly detectors have been proposed in literature. However, current methods are susceptible to anomalies in the processing window range and often make critical assumptions about the distribution of the background data. Motivated by the fact that anomaly pixels are often distinctive from their local background, in this letter, we proposed a novel hyperspectral anomaly detection framework for real-time remote sensing applications. The proposed framework consists of four major components, sparse feature learning, pyramid grid window selection, joint spatial-spectral collaborative coding and multi-level divergence fusion. It exploits the collaborative representation difference in the feature space to locate potential anomalies and is totally unsupervised without any prior assumptions. Experimental results on airborne recorded hyperspectral data demonstrate that the proposed methods adaptive to anomalies in a large range of sizes and is well suited for parallel processing.

  19. Audio Steganography: LSB Technique Using a Pyramid Structure and Range of Bytes

    Satish Bhalshankar

    2015-09-01

    Full Text Available The demand for keeping the information secure and confidential simultaneously has been progressively increasing. Among various techniques- Audio Steganography, a technique of embedding information transparently in a digital media thereby restricting the access to such information has been prominently developed. Imperceptibility, robustness, and payload or hiding capacity are the main character for it. In earlier, LSB techniques increased payload capacity would hamper robustness as well as imperceptibility of the cover media and vice versa. The proposed technique overcomes the problem. It provides relatively good improvement in the payload capacity by dividing the bytes of cover media into ranges to hide the bits of secret message appropriately. As well as due to the use of ranges of bytes the robustness of cover media has maintained and imperceptibility preserved by using a pyramid structure.

  20. Formation mechanism of graphite hexagonal pyramids by argon plasma etching of graphite substrates

    Glad, X.; de Poucques, L.; Bougdira, J.

    2015-12-01

    A new graphite crystal morphology has been recently reported, namely the graphite hexagonal pyramids (GHPs). They are hexagonally-shaped crystals with diameters ranging from 50 to 800 nm and a constant apex angle of 40°. These nanostructures are formed from graphite substrates (flexible graphite and highly ordered pyrolytic graphite) in low pressure helicon coupling radiofrequency argon plasma at 25 eV ion energy and, purportedly, due to a physical etching process. In this paper, the occurrence of peculiar crystals is shown, presenting two hexagonal orientations obtained on both types of samples, which confirms such a formation mechanism. Moreover, by applying a pretreatment step with different time durations of inductive coupling radiofrequency argon plasma, for which the incident ion energy decreases at 12 eV, uniform coverage of the surface can be achieved with an influence on the density and size of the GHPs.

  1. Fusion of remote sensing images based on pyramid decomposition with Baldwinian Clonal Selection Optimization

    Jin, Haiyan; Xing, Bei; Wang, Lei; Wang, Yanyan

    2015-11-01

    In this paper, we put forward a novel fusion method for remote sensing images based on the contrast pyramid (CP) using the Baldwinian Clonal Selection Algorithm (BCSA), referred to as CPBCSA. Compared with classical methods based on the transform domain, the method proposed in this paper adopts an improved heuristic evolutionary algorithm, wherein the clonal selection algorithm includes Baldwinian learning. In the process of image fusion, BCSA automatically adjusts the fusion coefficients of different sub-bands decomposed by CP according to the value of the fitness function. BCSA also adaptively controls the optimal search direction of the coefficients and accelerates the convergence rate of the algorithm. Finally, the fusion images are obtained via weighted integration of the optimal fusion coefficients and CP reconstruction. Our experiments show that the proposed method outperforms existing methods in terms of both visual effect and objective evaluation criteria, and the fused images are more suitable for human visual or machine perception.

  2. Atypical pyramidal cells in epileptic human cortex: CFLS and 3-D reconstructions.

    Belichencko, P; Dahlström, A; von Essen, C; Lindström, S; Nordborg, C; Sourander, P

    1992-09-01

    Epileptic temporal cortices, removed from 3 patients with intractable partial epilepsy (IPE) during neurosurgery, were studied. Pyramidal neurons (40-50 per slice) in laminae III, V and white matter, were injected with lucifer yellow. Samples were examined in a confocal laser scanning microscope (Biorad 600) and individual cells scanned at 0.1-1 microns incremental levels. 2-D maximal linear projection was used for overview. Frames (50-60) of scanned neurons were transformed into 3-D volumes, using VoxelView software on a Silicone Graphics workstation and rotated. All samples contained neurons with duplicated apical dendrites, additional basal dendrites or were misplaced in a horizontal position in the white matter. The relation between these preliminary observations and the disease is discussed. PMID:1421134

  3. Parallel two-level domain decomposition based Jacobi-Davidson algorithms for pyramidal quantum dot simulation

    Zhao, Tao; Hwang, Feng-Nan; Cai, Xiao-Chuan

    2016-07-01

    We consider a quintic polynomial eigenvalue problem arising from the finite volume discretization of a quantum dot simulation problem. The problem is solved by the Jacobi-Davidson (JD) algorithm. Our focus is on how to achieve the quadratic convergence of JD in a way that is not only efficient but also scalable when the number of processor cores is large. For this purpose, we develop a projected two-level Schwarz preconditioned JD algorithm that exploits multilevel domain decomposition techniques. The pyramidal quantum dot calculation is carefully studied to illustrate the efficiency of the proposed method. Numerical experiments confirm that the proposed method has a good scalability for problems with hundreds of millions of unknowns on a parallel computer with more than 10,000 processor cores.

  4. Paleoclimatic significance of lake level fluctuations in the Lahontan Basin. [Pyramid Lake, Nevada

    Benson, L.V.

    1980-08-01

    An energy flux balance model has been developed which treats evaporation as a function of air temperature, surface water temperature, precipitable water aloft, the amount, height, and type of sky cover, and the optical air mass. The model has been used to estimate the mean historical evaporation rate for Pyramid Lake, Nevada, using as input climatic data from the Reno area averaged over the period 1950 to 1975. Estimated and measured values of the mean annual evaporation rate were found to be in good agreement. The model was used to simulate changes in the level, the surface area and the volume of paleo Lake Lahontan. In particular, possible climatic states responsible for past high stands (1270 and 1330 m) were investigated. A conservative range of discharge values was used in the calculations. Results of the simulations indicate the fundamental importance of sky cover in the creation and destruction of large lake systems.

  5. Pyramidal texturing of silicon solar cell with TMAH chemical anisotropic etching

    Papet, P.; Nichiporuk, O.; Kaminski, A.; Rozier, Y.; Kraiem, J.; Lelievre, J.-F.; Chaumartin, A.; Fave, A.; Lemiti, M. [Laboratoire de Physique de la Matiere, UMR-CNRS 5511, Institut National des Sciences Appliquees de Lyon, Bat Blaise Pascal, 7 avenue Jean Capelle, 69621 Villeurbanne Cedex (France)

    2006-09-22

    High-efficiency silicon solar cells need a textured front surface to reduce reflectance and to improve light trapping. Texturing of monocrystalline silicon is usually done in alkaline solutions. These solutions are cheaper, but are pollutants of silicon technologies. In this paper, we investigate an alternative solution containing tetramethyl ammonium hydroxide ((CH{sub 3}){sub 4}NOH, TMAH ). This study shows the influence of different parameters (concentration, agitation, duration and temperature), to obtain uniform and reliable pyramidal texturization on different silicon surfaces (as cut, etched and polished). Under optimized conditions, TMAH-textured surface led to an average weighted reflectance of 13%, without any antireflection coating independent of the initial silicon surface. Unlike potassium hydroxide (KOH) texturing solution, characterization of silicon oxide layer contamination after TMAH texturing process revealed no pollution, and passivation is less affected by TMAH than by KOH texturization. (author)

  6. Evidence of different confinement regimes in site-controlled pyramidal InGaN structures

    We deposited InGaN on GaN micropyramids, which were grown by selective metal-organic vapor phase epitaxy on sapphire. We expected the formation of a quantum well on the side-walls of the pyramids, a quantum wire on the edges, and a quantum dot on its apex. We studied the emission properties of these structures using low-temperature time-resolved photoluminescence. Our measurements showed three regions of different confinement within the emission in the wavelength range between 2.12 eV and 2.40 eV. By analyzing the decay behavior, the characteristics of the luminescence was determined to originate from localized states. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Tonal response on the stairway of the main pyramid at La Ciudadela, Teotihuacan archaeological site

    Beristain, Sergio; Coss, Cecilia; Aquino, Gabriela; Negrete, Jose; Lizana, Pablo

    2002-11-01

    This paper presents new research on the very interesting audible effects produced by the stairways of many archaeological sites in Mexico. This investigation was made at the main stairway of the pyramid at La Ciudadela, Teotihuacan archaeological site. The effect previously studied was a chirped echo reflected from the stairway at normal incidence, which resembles the singing of the Quetzal. Now it is presented with the impulsive sound source and the listeners located at different angles, where apart from the characteristic chirped sound, several musical notes could be obtained and identified, covering a range of at least one half an octave. This evaluation was made at the site, where the effect is clearly audible, and it is supported with simple mathematics.

  8. Tissue Plasminogen Activator Expression Is Restricted to Subsets of Excitatory Pyramidal Glutamatergic Neurons.

    Louessard, Morgane; Lacroix, Alexandre; Martineau, Magalie; Mondielli, Gregoire; Montagne, Axel; Lesept, Flavie; Lambolez, Bertrand; Cauli, Bruno; Mothet, Jean-Pierre; Vivien, Denis; Maubert, Eric

    2016-09-01

    Although the extracellular serine protease tissue plasminogen activator (tPA) is involved in pathophysiological processes such as learning and memory, anxiety, epilepsy, stroke, and Alzheimer's disease, information about its regional, cellular, and subcellular distribution in vivo is lacking. In the present study, we observed, in healthy mice and rats, the presence of tPA in endothelial cells, oligodendrocytes, mastocytes, and ependymocytes, but not in pericytes, microglial cells, and astrocytes. Moreover, blockage of the axo-dendritic transport unmasked tPA expression in neurons of cortical and hippocampal areas. Interestingly, combined electrophysiological recordings, single-cell reverse transcription polymerase chain reaction (RT-PCR), and immunohistological analyses revealed that the presence of tPA is restricted to subsets of excitatory pyramidal glutamatergic neurons. We further evidenced that tPA is stored in synaptobrevin-2-positive glutamatergic synaptic vesicles. Based on all these data, we propose the existence of tPA-ergic neurons in the mature brain. PMID:26377106

  9. Mediatized Humanitarianism

    Vestergaard, Anne

    2014-01-01

    The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts to...... legitimate themselves and their moral claim were examined. A time trend analysis of the prioritization of actors in the material indicates that marked shifts in legitimation loci have taken place during the past 40 years. A discourse analysis unfolds the three dominant discourses behind these shifts, namely...... legitimation by accountancy, legitimation by institutionalization, and legitimation by compensation. The analysis relates these changes to a problem of trust associated with mediatization through processes of mediation....

  10. Numerical Study of Forced Air Cooling of a Heated Porous Foam Pyramid Array

    Anderson Kevin

    2015-01-01

    Full Text Available The current study employs CFD to study the forced air cooling of a pyramid shaped porous foam absorber. Herein, a three by three (33 array of porous foam absorbers heated with an external heat flux is modeled using the differential equations governing heat and fluid flow through porous media based on the Brinkman- Darcy flow equations and an effective thermal conductivity to account for the porous medium. The numerical simulations are carried out using the COMSOL commercial Computational Fluid Dynamics (CFD Finite Element based software package. The results of this verification exercise were within 18% of the prior numerical results and within 14% of the archived measured results. Typical results for the velocity and temperature profiles within the porous foam absorbers are shown. A comparison of Nusselt number between our CFD simulations and the heat transfer theory is plotted, showing agreement on the order of 11%. A parametric study involving heat flux, cooling air inlet velocity, porous foam porosity, and porous foam permeability showed that there is a relationship between porosity and the temperature distribution within the porous media. The primary finding of our study is that the more porous the foam absorber media is, the more dependent the effective thermal conductivity is on the thermal conductivity of the fluid used for cooling. If the fluid is air, which has a very low thermal conductivity, the effective thermal conductivity is decreased as the porosity increases, thus diminishing removal of heat from the foam array via the cooling air stream. Based on the parametric study, the best case operating conditions which may allow the pyramidal foam absorber to stay within the max allowable temperature are as follows: porosity = 0.472, inlet air cooling velocity = 50 m/s.

  11. Enhancement of an outwardly rectifying chloride channel in hippocampal pyramidal neurons after cerebral ischemia.

    Li, Jianguo; Chang, Quanzhong; Li, Xiaoming; Li, Xiawen; Qiao, Jiantian; Gao, Tianming

    2016-08-01

    Cerebral ischemia induces delayed, selective neuronal death in the CA1 region of the hippocampus. The underlying molecular mechanisms remain unclear, but it is known that apoptosis is involved in this process. Chloride efflux has been implicated in the progression of apoptosis in various cell types. Using both the inside-out and whole-cell configurations of the patch-clamp technique, the present study characterized an outwardly rectifying chloride channel (ORCC) in acutely dissociated pyramid neurons in the hippocampus of adult rats. The channel had a nonlinear current-voltage relationship with a conductance of 42.26±1.2pS in the positive voltage range and 18.23±0.96pS in the negative voltage range, indicating an outward rectification pattern. The channel is Cl(-) selective, and the open probability is voltage-dependent. It can be blocked by the classical Cl(-) channel blockers DIDS, SITS, NPPB and glibenclamide. We examined the different changes in ORCC activity in CA1 and CA3 pyramidal neurons at 6, 24 and 48h after transient forebrain ischemia. In the vulnerable CA1 neurons, ORCC activity was persistently enhanced after ischemic insult, whereas in the invulnerable CA3 neurons, no significant changes occurred. Further analysis of channel kinetics suggested that multiple openings are a major contributor to the increase in channel activity after ischemia. Pharmacological blockade of the ORCC partly attenuated cell death in the hippocampal neurons. We propose that the enhanced activity of ORCC might contribute to selective neuronal damage in the CA1 region after cerebral ischemia, and that ORCC may be a therapeutic target against ischemia-induced cell death. PMID:27181516

  12. Mediatized play

    Johansen, Stine Liv

    Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts........ In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....

  13. Mediating Business

    "Mediating Business" is a study of the expansion of business journalism. Building on evidence from Denmark, Finland, Norway and Sweden, "Mediating Business" is a comparative and multidisciplinary study of one of the major transformations of the mass media and the realm of business - nationally and...... globally. The book explores the history of key innovations and innovators in the business press. It analyzes changes in the discourse of business journalism associated with the growth in business news and the development of new ways of framing business issues and events. Finally, it examines the...... organizational implications of the increased media visibility of business and, in particular, the development of corporate governance and media relations....

  14. GABABR-Dependent Long-Term Depression at Hippocampal Synapses between CB1-Positive Interneurons and CA1 Pyramidal Cells.

    Jappy, Dave; Valiullina, Fliza; Draguhn, Andreas; Rozov, Andrei

    2016-01-01

    Activity induced long lasting modifications of synaptic efficacy have been extensively studied in excitatory synapses, however, long term plasticity is also a property of inhibitory synapses. Inhibitory neurons in the hippocampal CA1 region can be subdivided according to the compartment they target on the pyramidal cell. Some interneurons preferentially innervate the perisomatic area and axon hillock of the pyramidal cells while others preferentially target dendritic branches and spines. Another characteristic feature allowing functional classification of interneurons is cell type specific expression of different neurochemical markers and receptors. In the hippocampal CA1 region, nearly 90% of the interneurons expressing cannabinoid type 1 receptors (CB1R) also express cholecystokinin (CCK). Therefore, the functional presence of CB1 receptors can be used for identification of the inhibitory input from CCK positive (CCK+) interneurons to CA1 pyramidal cells. The goal of this study was to explore the nature of long term plasticity at the synapses between interneurons expressing CB1Rs (putative CCK+) and pyramidal neurons in the CA1 region of the hippocampus in vitro. We found that theta burst stimulation triggered robust long-term depression (LTD) at this synapse. The locus of LTD induction was postsynaptic and required activation of GABAB receptors. We also showed that LTD at this synaptic connection involves GABABR-dependent suppression of adenylyl cyclase and consequent reduction of PKA activity. In this respect, CB1+ to pyramidal cell synapses differ from the majority of the other hippocampal inhibitory connections where theta burst stimulation results in long-term potentiation. PMID:26858602

  15. Pirâmides alimentares: uma leitura semiótica Food guide pyramids: a semiotic way of reading

    Haydée Serrão Lanzillotti

    2005-12-01

    Full Text Available A semiótica é uma ciência que sistematiza e desvela o mundo dos signos, descrevendo-os e classificando-os segundo uma lógica. Existem três espécies de signos: ícones, índices e símbolos. As pirâmides alimentares são, primeiramente, ícones que podem se desenvolver até símbolos. Sob o enfoque da Nutrição, as pirâmides alimentares são consideradas ferramentas de orientação que podem transmitir conhecimentos relativos a uma alimentação considerada adequada. O objetivo deste trabalho foi avaliar o potencial comunicativo da pirâmide alimentar na perspectiva da semiótica. Neste ensaio, foram analisadas três pirâmides alimentares: United State Departament of Agriculture de 1992, de Philippi, de 1999 e de Willet e Stampfer, de 2003. O nível hierárquico em que o grupo de alimentos se encontra é o elemento informativo fundamental.Semiotics is a science that systematizes and reveals the world of signs, describing and classifying them according to logic. There are three kinds of sign: icons, indexes and symbols. The food guide pyramids are, in first place, icons, which can develop into symbols. Considering the focus of Nutrition, the food guide pyramids are considered as orientation tools that can transmit knowledge related to feeding considered adequate. The objective of this paper was to show the communicative potential of the food guide pyramids from the semiotics perspective. In this trial, three food guide pyramids were analyzed. The United States Department of Agriculture, 1992, Philippi, 1999 and Willet & Stampfer, 2003. In every food guide pyramid the hierarchic "level" in which a group of foods is found is the primordial informative element.

  16. A study on the analysis method of shape quality and the micro burr removal on a micro pyramid pattern using the micro MR fluid jet polishing system

    Lee, J. W.; Ha, S. J.; Hong, K. P.; Cho, Y. K.; Kim, K. B.; Kim, B. C.; Cho, M. W.

    2016-04-01

    Recently, micro square pyramid patterns which can be obtained by a light diffusion effect have been widely studied and examined. However, micro pyramid patterns are difficult to fabricate, because of a deburring problem. Therefore, a micro machining technology for the fabrication of micro pyramid patterns has emerged as an essential element. Burr can almost be generated on the edge of the micro pattern when the micro square pyramid pattern is manufactured by a mechanical cutting process. The micro pyramid pattern shape is difficult to maintain as an original form when the burrs are removed. So various methods have been used in an attempt to remove the burrs. A micro magnetorheological (MR) fluid jet polishing process is one of various methods to remove burrs. The process can control shear force for material removing it by a controlled viscosity of the MR fluid due to magnetic-field adjusting. In this paper, magnetic analysis and the deburring process were carried out to fabricate a micro square pyramid pattern on brass (non-magnetic material) and nickel (ferromagnetic material) using a micro MR fluid jet polishing system. Finally, the deburring characteristics and the shape analysis of micro pyramid patterns were investigated by using a micro MR fluid jet polishing system.

  17. Texturing a pyramid-like structure on a silicon surface via the synergetic effect of copper and Fe(III) in hydrofluoric acid solution

    Cao, Ming; Li, Shaoyuan; Deng, Jianxin; Li, Yuping; Ma, Wenhui; Zhou, Yang

    2016-05-01

    An innovative approach is proposed to texture a pyramid structure on a silicon surface via Cu-catalyzed chemical etching in the HF/FeCl3 system. The surface and cross-section morphologies of the formed pyramid structure were examined by scanning electron microscopy and atomic force microscopy. The results revealed that numerous silicon pyramid-like structures with hemlines of 0.1 ∼ 3 μm and height of 0.1 ∼ 2 μm are close together, and the top angle of the pyramid structure is 90°. Additionally, the systematic study of the effects of the etching time and the concentration of FeCl3 on the pyramid-like structures by the atom configuration model of silicon crystal faces demonstrated that the etching proceeds preferentially along the directions of silicon. A formation mechanism of the pyramid-like structure is proposed. The results imply that the synergetic effect of Cu nanoparticles and Fe(III) could conveniently generate a pyramid-like architecture on the surface of silicon in hydrofluoric acid solution.

  18. The influence of ion energy, target temperature, dose rate and crystal order on the shape of bombardment induced pyramids on copper crystals

    Following recent studies of energetic ion bombardment of copper, which established the conditions necessary for the production of cones/pyramids, investigations have been extended to include the effects of change in ion energy, target temperature and dose rate. In addition, the authors have attempted a detailed analysis of the influence of sample crystal orientation on the final form of pyramids and have investigated the stability of the pyramids as a function of the total dose. These experiments, as in earlier work, have been done using very pure copper, mass-analyzed ion beams and free of any metal contamination from, for example, defining apertures. (Auth.)

  19. Assessment of the pyramidal tract by diffusion tensor analysis in brain hemorrhage patients for motor function prognosis

    In patients with brain hemorrhage, the entire visualized pyramidal tract was established as an area of interest (ROI). Its Fractional Anisotropy (FA) value was determined by diffusion tensor analysis (DTA), and its relationship to motor function at the onset and three months later was investigated. In 30 patients with brain hemorrhage accompanying paralysis, MRI was performed during the subacute phase (6-14 days after onset). In addition, using a workstation, DTA was performed in order to visualize the pyramidal tract. The FA of the ROI was measured on the affected and unaffected sides, and as previously reported, the ratio of FA in the affected and unaffected sides was calculated. Subsequently, we examined the relationship between the FA ratio and motor function prognosis. Motor function prognosis was assessed based on the sum of the Brunnstrom stage at the onset and three months later. A strong correlation coefficient existed between the FA ratio of the entire pyramidal tract and the sum of the Brunnstrom stage three months after onset (0.74, p<0.001), and prognosis of motor function tended to improve in patients with FA ratios of 0.95 or higher. Patients with mild paralysis were identified in order to ascertain the degree of improvement in paralysis, and a significant correlation between the FA ratio of the entire pyramidal tract and the degree of improvement in the Brunnstrom stage was observed (correlation coefficient 0.77, p<0.001). When compared to putamen hemorrhage, the FA ratio affected the prognosis of paralysis more in thalamic hemorrhage. The results suggest that in patients with an FA ratio of 1.0, the recovery rate of paralysis three months after onset is markedly high. In brain hemorrhage patients, a reduction in the FA ratio of the entire pyramidal tract was correlated with the functional prognosis of motor paralysis, and in thalamic hemorrhage, it may be possible to predict motor function based on FA ratios. Hence, the DTA of the pyramidal tract

  20. Effect of size on electronic states in a strained pyramidal InAs-GaAs quantum dot system

    The effect of size on electronic states in a strained pyramidal InAs-GaAs quantum dot system was studied. A comparison was made between two InAs quantum pyramids of different sizes embedded inside a cubic GaAs susbtrate material. Strain relaxation was carried out via the Metropolis Monte Carlo method and the calculated local strain tensors were then included to solve the energy values and the wave functions of the electronic states inside the two simulation cube. The 3D finite difference scheme was employed to solve the time independent Schrödinger equation based on the decoupled electron-hole model. Calculated energy values of the four lowest electronic states showed that the transitions between the electron and hole states widen as the size of the dot becomes smaller especially between the ground states. The confinement of electrons and holes become weaker as the size of the dot reduces

  1. Growth and structural characterization of pyramidal site-controlled quantum dots with high uniformity and spectral purity

    Dimastrodonato, Valeria; Young, Robert J; Pelucchi, Emanuele

    2010-01-01

    This work presents some fundamental features of pyramidal site-controlled InGaAs Quantum Dots (QDs) grown by MetalOrganic Vapour Phase Epitaxy on patterned GaAs (111)B substrate. The dots self-form inside pyramidal recesses patterned on the wafer via pre-growth processing. The major advantage of this growth technique is the control it provides over the dot nucleation posi-tion and the dimensions of the confined structures onto the sub-strate. The fundamental steps of substrate patterning and the QD forma-tion mechanism are described together with a discussion of the structural particulars. The post-growth processes, including sur-face etching and substrate removal, which are required to facili-tate optical characterization, are discussed. With this approach extremely high uniformity and record spectral purity are both achieved.

  2. Effect of size on electronic states in a strained pyramidal InAs-GaAs quantum dot system

    Ripan, G. H., E-mail: gregoryhr@gmail.com [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Faculty of Applied Science & Foundation Studies, Infrastructure University Kuala Lumpur, 43000 Kajang, Selangor (Malaysia); Woon, C. Y.; Gopir, G. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    The effect of size on electronic states in a strained pyramidal InAs-GaAs quantum dot system was studied. A comparison was made between two InAs quantum pyramids of different sizes embedded inside a cubic GaAs susbtrate material. Strain relaxation was carried out via the Metropolis Monte Carlo method and the calculated local strain tensors were then included to solve the energy values and the wave functions of the electronic states inside the two simulation cube. The 3D finite difference scheme was employed to solve the time independent Schrödinger equation based on the decoupled electron-hole model. Calculated energy values of the four lowest electronic states showed that the transitions between the electron and hole states widen as the size of the dot becomes smaller especially between the ground states. The confinement of electrons and holes become weaker as the size of the dot reduces.

  3. 1.55 μm InAs quantum dot distribution on truncated InP pyramids and regrowth by selective area epitaxy

    Position and distribution control of 1.55-μm InAs quantum dots (QDs) on truncated InP pyramids grown by selective area Metal Organic Vapor Phase Epitaxy (MOVPE) is reported. The arrangement of the {103}, {115}, and (100) facets on the pyramid top surface is governed by the shape of the pyramid base and top surface area. This allows the precise position and distribution control of the QDs due to preferential nucleation on the {103} and {115} facets. With shrinking QD number upon reduced top surface area, sharp emission from single QDs is observed at 1.55 μm. Regrowth of a passive InP structure around the pyramids establishes submicrometer-scale active-passive integration for efficient microcavity QD nanolasers and single photon sources operating in the 1.55-μm telecom wavelength region and their implementation in photonic integrated circuits.

  4. Research on Legal Issues of Struggling Against Pyramid Selling%打击传销法律问题研究

    纪荣荣

    2015-01-01

    20世纪80年代以来,传销作为一种经济现象在我国传播和发展,随着其负面作用日益显现,从政策、法律层面对此予以规范,并取得阶段性成果,但根绝传销问题还需要长期努力。一是要进一步完善打击传销法律制度,推进依法治理;二是要创新社会治理体制,推进社会治理体系现代化;三是要推动全社会树立法治意识,形成杜绝传销的良好社会氛围。%Since the 1980s,as economic phenomenon,pyramid selling has spread and developed in China. With the increas⁃ing emergence of its negative effect,pyramid selling is standardized from the aspects of policies and law,and phased achieve⁃ments are acquired. However,it still needs long-term efforts to eradicate its problems. One is to further improve the legal sys⁃tem against pyramid selling,and promote governance based on law; the second is to innovate the social management system, and promote the modernization of social governance system; the third is to give impetus to law consciousness for the whole so⁃ciety,and build up the good atmosphere of eliminating pyramid selling.

  5. Pattern and inhibition-dependent invasion of pyramidal cell dendrites by fast spikes in the hippocampus in vivo.

    Buzsáki, G.; Penttonen, M; Nádasdy, Z; Bragin, A.

    1996-01-01

    The invasion of sodium spikes from the soma into dendrites was studied in hippocampal pyramidal cells by simultaneous extracellular and intracellular recordings in anesthetized rats and by simultaneous extracellular recordings of the somatic and dendritic potentials in freely behaving animals. During complex-spike patterns, recorded in the immobile or sleeping animal, dendritic invasion of successive spikes was substantially attenuated. Complex-spike bursts occurred in association with popula...

  6. Segmentation and Positioning in the Brazilian Kids Market: A Case Study on the Bottom of the Pyramid

    Andres Rodriguez Veloso

    2012-07-01

    Full Text Available This article approaches the kids market, focusing on the Bottom of the Pyramid. A case study is developed within the toy industry. Because few studies have been developed on this subject (kids marketing, the option of this study is to focus on basic marketing strategies, market segmentation and positioning. Results exemplify how can a company structure its marketing strategy in order to have a clear focus on a given segment of the kids market.

  7. Co-creation of value at the bottom of the pyramid: Analysing Bangladeshi farmers' use of mobile telephony

    Dey, BL; Pandit, A.; Saren, M; Bhowmick, S; Woodruffe-Burton, H

    2015-01-01

    Existing literature offers scant evidence of how BoP (bottom of the pyramid) consumers with limited product knowledge and interaction with product designers and marketers can co-create value. The current paper addresses this issue by analysing Bangladeshi farmers’ use of mobile telephony. The findings suggest the value-in-use is facilitated or inhibited by product features, socio-economic practices, individuals’ capabilities and the appropriation of mobile telephony. The paper demonstrates ho...

  8. Quantifying the telecommunication opportunity at the base of the pyramid in South Africa : a retail perspective / Ignatius Meyer

    Meyer, Ignatius

    2014-01-01

    This study focuses on the telecommunication industry, specifically the mobile phone market at the base of the pyramid (BOP). A supply vs. demand stance is taken whereby demographic data offer insight into the demand while the location of telecommunication retail stores constitutes supply. The study furthermore makes extensive use of a GIS (geographical information system) which offers deeper insight into data and different applications thereof. Given the extensive nature of the data used in a...

  9. Specificity of Synaptic Connectivity between Layer 1 Inhibitory Interneurons and Layer 2/3 Pyramidal Neurons in the Rat Neocortex

    Wozny, Christian; Stephen R Williams

    2011-01-01

    Understanding the structure and function of the neocortical microcircuit requires a description of the synaptic connectivity between identified neuronal populations. Here, we investigate the electrophysiological properties of layer 1 (L1) neurons of the rat somatosensory neocortex (postnatal day 24–36) and their synaptic connectivity with supragranular pyramidal neurons. The active and passive properties of visually identified L1 neurons (n = 266) suggested division into 4 groups according to...

  10. Postnatal development of layer III pyramidal cells in the primary visual, inferior temporal, and prefrontal cortices of the marmoset

    Hirosato eAoi; Tomofumi eOga; Tetsuya eSasaki; Ichiro eFujita; Noritaka eIchinohe

    2013-01-01

    Abnormalities in the processes of the generation and/or pruning of dendritic spines have been implicated in several mental disorders including autism and schizophrenia. We have chosen to examine the common marmoset (Callithrix jacchus) as a primate model to explore the processes. As a first step, we studied the postnatal development of basal dendritic trees and spines of layer-III pyramidal cells in the primary visual sensory cortex (V1), a visual association cortex (inferior temporal area, T...

  11. Introgression and pyramiding into common bean market class fabada of genes conferring resistance to anthracnose and potyvirus

    Ferreira, J. J.; Campa, Ana; Pérez-Vega, Elena; Rodríguez-Suárez, Cristina; Giráldez, Ramón

    2014-01-01

    Anthracnose and bean common mosaic (BCM) are considered major diseases in common bean crop causing severe yield losses worldwide. This work describes the introgression and pyramiding of genes conferring genetic resistance to BCM and anthracnose local races into line A25, a bean genotype classified as market class fabada. Resistant plants were selected using resistance tests or combining resistance tests and marker-assisted selection. Lines A252, A321, A493, Sanilac BC6-Are, and BRB130 were us...

  12. Reconfigurable pyramidal antenna loaded by a cut-off waveguide-application to ARNS/RNSS services

    Hebib, Sami; Aubert, Hervé; Pascal, Olivier; Fonseca, Nelson; Ries, Lionel; Lopez, Jean-Marc

    2009-01-01

    International audience A novel reconfigurable and circularly polarized antenna topology for satellite application services, based on a pyramidal geometry, is proposed. Frequency agility is simply obtained by loading the radiating elements by Radio-Frequency switches. The ground plane of the antenna is perforated and loaded by a cut-off and open-ended waveguide. The length of this waveguide is adjusted to achieve a good trade-off between rear radiation and impedance matching. A specific app...

  13. Multiperspectives of Mobile Money System Development at the Base of the Pyramid: Case of e-Masary in Egypt

    Mostafa Mohamad, Trevor Wood-Harper & Ronnie Ramlogan

    2013-01-01

    This paper highlights how the motives, utility and benefits, and challenges of Mobile Money Systems (MMS) shape the financial inclusion in today’s dynamic environment and increase its sustainability. Recently, Mobile Network Operators (MNOs) have been acting as financial service providers to tap the unbanked population at the Base of the Pyramid market (BoP). This approach of bankless banking requires a network of private, non-governmental, retail agents, and governmental organizations to dev...

  14. The Environmental (Un)sustainability of the Base-of-the-Pyramid (BOP) Philosophy: A Governance Perspective

    Wijen, Frank

    2008-01-01

    textabstractThe Base- or Bottom-of-the-Pyramid (BOP) philosophy has rapidly gained currency in business, following seminal articles and books in the popular management literature (Prahalad and Hammond, 2002; Hart and Christensen, 2002; Prahalad, 2005; Hart, 2005). The thrust of the BOP philosophy is to achieve economic and social development to four billion persons with very low incomes through a practical business model that proposes decentralized, often small-scale production and consumptio...

  15. Site-controlled InGaAs/GaAs pyramidal quantum dots grown by MOVPE on patterned substrates using triethylgallium

    Rigal, B.; Jarlov, C.; Rudra, A.; Gallo, P.; Lyasota, A.; Dwir, B.; Kapon, E.

    2015-03-01

    The fabrication and characterization of site-controlled InGaAs/GaAs quantum dots (QDs) made by MOVPE using triethylgallium (TEGa) on patterned {1 1 1}B GaAs substrates are reported. Results are compared to more traditional pyramidal QD structures grown employing trimethylgallium (TMGa). Several potential advantages of the use of TEGa are demonstrated, including more reproducible achievement of QD transitions with narrow (integration in optical cavities, which require both site and spectral stringent control.

  16. Akhet Khufu: archaeo-astronomical hints at a common project of the two main pyramids of Giza, Egypt

    Magli, Giulio

    2007-01-01

    The architectural complexes composed by the two main pyramids of Giza together with their temples are investigated from an inter-disciplinary point of view, taking into account their astronomical alignments as well as their relationships with the visible landscape. Combining already known facts together with new clues, the work strongly supports the idea that the two complexes were conceived as parts of a common project.

  17. Approximation of H(div) with High-Order Optimal Finite Elements for Pyramids, Prisms and Hexahedra

    Bergot, Morgane; Duruflé, Marc

    2013-01-01

    Classical facet elements do not provide an optimal rate of convergence of the numerical solution toward the solution of the exact problem in H(div)-norm for general unstructured meshes containing hexahedra and prisms. We propose two new families of high-order elements for hexahedra, triangular prisms and pyramids that recover the optimal convergence. These elements have compatible restrictions with each other, such that they can be used directly on general hybrid meshes. Moreover the H(div) p...

  18. Concurrent use of transgenic plants expressing a single and two Bacillus thuringiensis genes speeds insect adaptation to pyramided plants

    Zhao, Jian-Zhou; Cao, Jun; Collins, Hilda L.; Bates, Sarah L.; Roush, Richard T.; Earle, Elizabeth D.; Anthony M Shelton

    2005-01-01

    Transgenic plants expressing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) were grown on over 13 million ha in the United States and 22.4 million ha worldwide in 2004. Preventing or slowing the evolution of resistance by insects (“resistance management”) is critical for the sustainable use of Bt crops. Plants containing two dissimilar Bt toxin genes in the same plant (“pyramided”) have the potential to delay insect resistance. However, the advantage of pyramided Bt plan...

  19. The Electrotonic Structure of Pyramidal Neurons Contributing to Prefrontal Cortical Circuits in Macaque Monkeys Is Significantly Altered in Aging

    Kabaso, Doron; Coskren, Patrick J; Henry, Bruce I; Patrick R Hof; Wearne, Susan L.

    2009-01-01

    Whereas neuronal numbers are largely preserved in normal aging, subtle morphological changes occur in dendrites and spines, whose electrotonic consequences remain unexplored. We examined age-related morphological alterations in 2 types of pyramidal neurons contributing to working memory circuits in the macaque prefrontal cortex (PFC): neurons in the superior temporal cortex forming “long” projections to the PFC and “local” projection neurons within the PFC. Global dendritic mass homeostasis, ...

  20. Attentional modulation of firing rate varies with burstiness across putative pyramidal neurons in macaque visual Area V4

    Anderson, Emily B.; Mitchell, Jude F.; Reynolds, John H.

    2011-01-01

    One of the most well established forms of attentional modulation is an increase in firing rate when attention is directed into a neuron’s receptive field. The degree of rate modulation, however, can vary considerably across individual neurons, especially among broad spiking neurons (putative pyramids). We asked whether this heterogeneity might be correlated with a neuronal response property that is used in intracellular recording studies to distinguish among distinct neuronal classes: the bur...

  1. SELECTED METHODOLOGICAL APPROACHES TO THE PYRAMID DECOMPOSITION OF RETURN ON ASSETS FOR THE FINANCIAL NEEDS OF CORPORATE GOVERNANCE

    Ratislav Kotulic; Miroslava Rajcaniova

    2011-01-01

    The most important factor often determining the prosperity or bankruptcy is the ability of the firm to make correct decisions in financial management questions. Like every decision, the decisions on the level of financial management must be based on detailed financial analysis. Pyramid systems of financial and economic indicators are therefore inevitable and extremely important tools of the financial analysis. They are able to capture the different processes and relations in the enterprise. T...

  2. Ingénierie frugale pour les bases de la Pyramide : concevoir des produits ouverts pour des contextes multiples

    Lecomte, Chloé

    2014-01-01

    Globalization of markets, rapid growth of emerging countries, challenges of a sustainable design and needs of low-income populations trigger companies to look for new forms of organization and innovation. The Base of the Pyramid (BoP) theory takes root on these challenges and suggests fighting against poverty while generating economic growth. Although recent, the literature on this topic is diverse and today falls mainly in management and economic sciences. The contributions in the field of e...

  3. Models of neocortical layer 5b pyramidal cells capturing a wide range of dendritic and perisomatic active properties.

    Etay Hay

    2011-07-01

    Full Text Available The thick-tufted layer 5b pyramidal cell extends its dendritic tree to all six layers of the mammalian neocortex and serves as a major building block for the cortical column. L5b pyramidal cells have been the subject of extensive experimental and modeling studies, yet conductance-based models of these cells that faithfully reproduce both their perisomatic Na(+-spiking behavior as well as key dendritic active properties, including Ca(2+ spikes and back-propagating action potentials, are still lacking. Based on a large body of experimental recordings from both the soma and dendrites of L5b pyramidal cells in adult rats, we characterized key features of the somatic and dendritic firing and quantified their statistics. We used these features to constrain the density of a set of ion channels over the soma and dendritic surface via multi-objective optimization with an evolutionary algorithm, thus generating a set of detailed conductance-based models that faithfully replicate the back-propagating action potential activated Ca(2+ spike firing and the perisomatic firing response to current steps, as well as the experimental variability of the properties. Furthermore, we show a useful way to analyze model parameters with our sets of models, which enabled us to identify some of the mechanisms responsible for the dynamic properties of L5b pyramidal cells as well as mechanisms that are sensitive to morphological changes. This automated framework can be used to develop a database of faithful models for other neuron types. The models we present provide several experimentally-testable predictions and can serve as a powerful tool for theoretical investigations of the contribution of single-cell dynamics to network activity and its computational capabilities.

  4. Beyond bag of latent topics:spatial pyramid matching for scene category recognition

    Fu-xiang LU; Jun HUANG

    2015-01-01

    We propose a heterogeneous, mid-level feature based method for recognizing natural scene categories. The proposed feature introduces spatial information among the latent topics by means of spatial pyramid, while the latent topics are obtained by using probabilistic latent semantic analysis (pLSA) based on the bag-of-words representation. The proposed feature always performs better than standard pLSA because the performance of pLSA is adversely affected in many cases due to the loss of spatial information. By combining various interest point detectors and local region descriptors used in the bag-of-words model, the proposed feature can make further improvement for diverse scene category recognition tasks. We also propose a two-stage framework for multi-class classifi cation. In the fi rst stage, for each of possible detector/descriptor pairs, adaptive boosting classifi ers are employed to select the most discriminative topics and further compute posterior probabilities of an unknown image from those selected topics. The second stage uses the prod-max rule to combine information coming from multiple sources and assigns the unknown image to the scene category with the highest'fi nal' posterior probability. Experimental results on three benchmark scene datasets show that the proposed method exceeds most state-of-the-art methods.

  5. Radiation measurements in Egyptian pyramids and tombs -- occupational exposure of workers and the public

    A radiation survey of seven archaeological sites within Egyptian pyramids and tombs has been conducted in the Saggara area. Measurements were made of radon (222Rn) and its short-lived decay products (progeny), as well as thoron (220Rn) progeny and γ-radiation. The results of these measurements have been used to calculate the maximum annual effective dose (MAD) and other important occupational radiation exposure variables. It was found that for the limited time to which occupational workers and visitors were exposed, their respective MAD values were lower than that recommended by the regulatory agency (i.e., 20 mSv per year for occupational workers and 1 mSv in a year for the public). However, it is shown that if the exposure times for occupational workers were to increase to 'normal' working schedules their MAD would be exceeded at three archaeological sites. Implementation of improved ventilation practices is recommended in those sites to reduce the exposure to occupational workers were their working schedules to be significantly increased. It is also recommended that further monitoring be conducted in the future to verify these results

  6. CT detection of thyroid pyramidal lobe in preoperative patients with thyroid tumors

    Thyroid pyramidal lobe (TPL) is a normal variant of the thyroid gland, but few imaging studies of TPL have been published. The purpose of this study is to investigate the frequency, location, size (length, maximal AP diameter, maximal transverse diameter), and upper end level of TPL with its separation from the main thyroid gland on preoperative neck CT and to compare them with operative findings in order to assess the diagnostic accuracy of neck CT for detection TPL. 46 patients, who underwent preoperative neck CT before thyroidectomy, were included in the study. The frequency, location, size, and upper end level of TPL with its separation from the main thyroid gland on the neck CT was analyzed by a single radiologist. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of neck CT for detecting TPL was 77.8%, 89.5%, 91.3%, 73.9% and 82.6%. There was a significant difference in maximal AP diameter, location, upper end level, and its separation from main thyroid gland between CT and operative findings (p 0.05). Diagnostic accuracy of neck CT for detecting TPL was high, and the neck CT may be useful for evaluating TPL in the suprahyoid neck.

  7. Mild N-O Bond Cleavage Reactions of a Pyramidalized Nitrosyl Ligand Bridging a Dimolybdenum Center.

    Alvarez, M Angeles; García, M Esther; García-Vivó, Daniel; Ruiz, Miguel A; Toyos, Adrián

    2015-11-16

    Complex [Mo2Cp2(μ-PCy2)(μ-NO)(NO)2] (1) was prepared by reacting [Mo2Cp2(μ-H)(μ-PCy2)(CO)4] with 2 equiv of [NO]BF4 and then treating the resulting product [Mo2Cp2(μ-PCy2)(CO)2(NO)2](BF4) with NaNO2 at 323 K, and it was shown to display a bridging nitrosyl ligand with significant pyramidalization at the N atom, a circumstance related to an unusual behavior concerning degradation of the bridging nitrosyl. Indeed, complex 1 reacts with HBF4·OEt2 to give the nitroxyl-bridged derivative [Mo2Cp2(μ-PCy2)(μ-κ(1):η(2)-HNO)(NO)2](BF4), is reduced by Zn(Hg) in the presence of trace H2O to give the amido complex [Mo2Cp2(μ-PCy2)(μ-NH2)(NO)2], and reacts with excess P(OPh)3 to give the phosphoraniminato-bridged derivative [Mo2Cp2(μ-PCy2){μ-NP(OPh)3}(NO)2]. PMID:26529181

  8. Strong modulation of plasmons in Graphene with the use of an Inverted pyramid array diffraction grating

    Matthaiakakis, N.; Mizuta, H.; Charlton, M. D. B.

    2016-06-01

    An optical device configuration allowing efficient electrical tuning of surface plasmon wavelength and absorption in a suspended/conformal graphene film is reported. An underlying 2-dimensional array of inverted rectangular pyramids greatly enhances optical coupling to the graphene film. In contrast to devices utilising 1D grating or Kretchman prism coupling configurations, both s and p polarization can excite plasmons due to symmetry of the grating structure. Additionally, the excited high frequency plasmon mode has a wavelength independent of incident photon angle allowing multidirectional coupling. By combining analytical methods with Rigorous Coupled-Wave Analysis, absorption of plasmons is mapped over near infrared spectral range as a function of chemical potential. Strong control over both plasmon wavelength and strength is provided by an ionic gel gate configuration. 0.04eV change in chemical potential increases plasmon energy by 0.05 eV shifting plasmon wavelength towards the visible, and providing enhancement in plasmon absorption. Most importantly, plasmon excitation can be dynamically switched off by lowering the chemical potential and moving from the intra-band to the inter-band transition region. Ability to electrically tune plasmon properties can be utilized in applications such as on-chip light modulation, photonic logic gates, optical interconnect and sensing applications.

  9. Infrared and multi-type images fusion algorithm based on contrast pyramid transform

    Xu, Hua; Wang, Yan; Wu, Yujing; Qian, Yunsheng

    2016-09-01

    A fusion algorithm for infrared and multi-type images based on contrast pyramid transform (CPT) combined with Otsu method and morphology is proposed in this paper. Firstly, two sharpened images are combined to the first fused image based on information entropy weighted scheme. Afterwards, two enhanced images and the first fused one are decomposed into a series of images with different dimensions and spatial frequencies. To the low-frequency layer, the Otsu method is applied to calculate the optimal segmentation threshold of the first fused image, which is subsequently used to determine the pixel values in top layer fused image. With respect to the high-frequency layers, the top-bottom hats morphological transform is employed to each layer before maximum selection criterion. Finally, the series of decomposed images are reconstructed and then superposed with the enhanced image processed by morphological gradient operation as a second fusion to get the final fusion image. Infrared and visible images fusion, infrared and low-light-level (LLL) images fusion, infrared intensity and infrared polarization images fusion, and multi-focus images fusion are discussed in this paper. Both experimental results and objective metrics demonstrate the effectiveness and superiority of the proposed algorithm over the conventional ones used to compare.

  10. A fusion algorithm for remote sensing images based on nonsubsampled pyramids and bidimensional empirical decomposition

    2010-01-01

    In order to improve the quality of remote sensing image fusion,a new method combining nonsubsampled Laplacian pyramid (NLP)and bidimensional empirical mode decomposition(BEMD)is proposed.First,the high resolution panchromatic image (PAN)is decomposed using NLP until the approximate component and the low resolution multispectral image(MS)contain features with a similar scale.Then,the approximation component and the MS are decomposed by BEMD,resulting in a number of bidimensional intrinsic mode functions(BIMF)and a residue respectively.The instantaneous frequency is computed in 4 directions of the BIMFs.Considering the positive or negative coefficients in the corresponding position,a weighted algorithm is designed for fusing the high frequency details using the instantaneous frequency and the coefficient absolute value of the BIMFs as fusion feature.The fused image is then obtained through inverse BEMD and NLP.Experimental results have illustrated the advantage of this method over the IHS,DWT andà-Trous wavelet in both spectral and spatial detail qualities.

  11. Antireflective nanostructures fabricated by reactive ion etching method on pyramid-structured silicon surface

    In this paper, pyramid-structured silicon wafers were etched in a reactive ion etching system at room temperature and without any negative voltage pulses to obtain antireflective nanostructures. The effects of the etching time, etching power and the flow ratio of the SF6 and O2 (FSF6/FO2) on the morphologies and reflective properties of the etched samples were studied. Scanning electron microscope was used to investigate the morphologies of etched samples. The surface reflectance measurements were carried out using UV–vis-NIR spectrophotometer. A reflectance of 4.72% from the etched surface in the wavelength range of 400–800 nm was obtained under etching time of 20 min, etching power of 150 W and FSF6/FO2 of 18 sccm/6 sccm. Meanwhile, samples etched with FO2 lower than 6 sccm can’t get low reflective silicon structure. Besides, the results show that overlong etching time of 30 min and too big etching power of 225 W would make the nanostructures too sparse to obtain a low reflectance.

  12. Investigating the construction of pyramid super-structures to dispose of radioactive and hazardous waste

    Since the 1950's, the United States and other countries have focused on utilizing open-quotes natural barriersclose quotes for disposing of dangerous radioactive and hazardous waste. The Waste Isolation Pilot Projects and Yucca Mountain Project seem practical as well as economical. However, the technical challenges involved in disposing of the waste have been underestimated. For example, geological waste disposal has difficulty in demonstrating reliability, guaranteeing protection against climatic changes or natural disasters (or combinations thereof), or ability to retrieve waste under adverse scenarios. Much has changed since the 1950's. Technology has advanced dramatically in the areas of materials, science, and engineering. As a result, traditional approaches to waste disposal should be rethought, focusing instead on ways to apply technology breakthroughs to waste disposal problems. This paper proposes investigating the construction of fully retrievable waste disposal systems that resemble pyramid structures and rely totally on engineered barriers and preventive measurements to dispose and store radioactive and hazardous waste. This paper will describe problems currently faced by waste disposal systems that rely on natural barriers. Specific benefits demonstrated will detail the structures flexibility and durability in a number of areas

  13. CT detection of thyroid pyramidal lobe in preoperative patients with thyroid tumors

    Shin, Gi Won; Kim, Dong Won [Dept. of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2013-10-15

    Thyroid pyramidal lobe (TPL) is a normal variant of the thyroid gland, but few imaging studies of TPL have been published. The purpose of this study is to investigate the frequency, location, size (length, maximal AP diameter, maximal transverse diameter), and upper end level of TPL with its separation from the main thyroid gland on preoperative neck CT and to compare them with operative findings in order to assess the diagnostic accuracy of neck CT for detection TPL. 46 patients, who underwent preoperative neck CT before thyroidectomy, were included in the study. The frequency, location, size, and upper end level of TPL with its separation from the main thyroid gland on the neck CT was analyzed by a single radiologist. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of neck CT for detecting TPL was 77.8%, 89.5%, 91.3%, 73.9% and 82.6%. There was a significant difference in maximal AP diameter, location, upper end level, and its separation from main thyroid gland between CT and operative findings (p < 0.05), but there was no significant difference in the length and maximal transverse diameter of TPL (p > 0.05). Diagnostic accuracy of neck CT for detecting TPL was high, and the neck CT may be useful for evaluating TPL in the suprahyoid neck.

  14. Comparison of activity of individual pyramidal tract neurons during balancing, locomotion, and scratching.

    Beloozerova, Irina N; Sirota, Mikhail G; Orlovsky, Grigori N; Deliagina, Tatiana G

    2006-04-25

    Neuronal mechanisms of the spinal cord, brainstem, and cerebellum play a key role in the control of complex automatic motor behaviors-postural corrections, stepping, and scratching, whereas the role of the motor cortex is less clear. To assess this role, we recorded fore and hind limb-related pyramidal tract neurons (PTNs) in the cat during postural corrections and during locomotion; hind limb PTNs were also tested during scratching. The activity of nearly all PTNs was modulated in the rhythm of each of these motor patterns. The discharge frequency, averaged over the PTN population, was similar in different motor tasks, whereas the degree of frequency modulation was larger during locomotion. In individual PTNs, a correlation between analogous discharge characteristics (frequency or its modulation) in different tasks was very low, suggesting that input signals to PTNs in these tasks have a substantially different origin. In about a half of PTNs, their activity in different tasks was timed to the analogous (flexor/extensor) parts of the cycle, suggesting that these PTNs perform similar functions in these tasks (e.g., control of the value of muscle activity). In another half of PTNs, their activity was timed to opposite parts of the cycle in different tasks. These PTNs seem to perform different motor functions in different tasks, or their targets are active in different parts of the cycle in these tasks, or their effects are not directly related to the control of motor output (e.g., they modulate transmission of afferent signals). PMID:16445992

  15. Ancient and Modern Laminated Composites - From the Great Pyramid of Gizeh to Y2K

    Wadsworth, J.; Lesuer, D.R.

    2000-03-14

    Laminated metal composites have been cited in antiquity; for example, a steel laminate that may date as far back as 2750 B.C., was found in the Great Pyramid in Gizeh in 1837. A laminated shield containing bronze, tin, and gold layers, is described in detail by Homer. Well-known examples of steel laminates, such as an Adze blade, dating to 400 B.C. can be found in the literature. The Japanese sword is a laminated composite at several different levels and Merovingian blades were composed of laminated steels. Other examples are also available, including composites from China, Thailand, Indonesia, Germany, Britain, Belgium, France, and Persia. The concept of lamination to provide improved properties has also found expression in modern materials. Of particular interest is the development of laminates including high carbon and low carbon layers. These materials have unusual properties that are of engineering interest; they are similar to ancient welded Damascus steels. The manufacture of collectable knives, labeled ''welded Damascus'', has also been a focus of contemporary knifemakers. Additionally, in the Former Soviet Union, laminated composite designs have been used in engineering applications. Each of the above areas will be briefly reviewed, and some of the metallurgical principles will be described that underlie improvement in properties by lamination. Where appropriate, links are made between these property improvements and those that may have been present in ancient artifacts.

  16. Similar GABAA receptor subunit composition in somatic and axon initial segment synapses of hippocampal pyramidal cells.

    Kerti-Szigeti, Katalin; Nusser, Zoltan

    2016-01-01

    Hippocampal pyramidal cells (PCs) express many GABAAR subunit types and receive GABAergic inputs from distinct interneurons. Previous experiments revealed input-specific differences in α1 and α2 subunit densities in perisomatic synapses, suggesting distinct IPSC decay kinetics. However, IPSC decays evoked by axo-axonic, parvalbumin- or cholecystokinin-expressing basket cells were found to be similar. Using replica immunogold labeling, here we show that all CA1 PC somatic and AIS synapses contain the α1, α2, β1, β2, β3 and γ2 subunits. In CA3 PCs, 90% of the perisomatic synapses are immunopositive for the α1 subunit and all synapses are positive for the remaining five subunits. Somatic synapses form unimodal distributions based on their immunoreactivity for these subunits. The α2 subunit densities in somatic synapses facing Cav2.1 (i.e. parvalbumin) or Cav2.2 (cholecystokinin) positive presynaptic active zones are comparable. We conclude that perisomatic synapses made by three distinct interneuron types have similar GABAA receptor subunit content. PMID:27537197

  17. Antireflective nanostructures fabricated by reactive ion etching method on pyramid-structured silicon surface

    Yue, Zhihao [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China); Shen, Honglie, E-mail: hlshen@nuaa.edu.cn [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China); Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, Institute of Nanoscience, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China); Jiang, Ye [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China)

    2013-04-15

    In this paper, pyramid-structured silicon wafers were etched in a reactive ion etching system at room temperature and without any negative voltage pulses to obtain antireflective nanostructures. The effects of the etching time, etching power and the flow ratio of the SF{sub 6} and O{sub 2} (F{sub SF6}/F{sub O2}) on the morphologies and reflective properties of the etched samples were studied. Scanning electron microscope was used to investigate the morphologies of etched samples. The surface reflectance measurements were carried out using UV–vis-NIR spectrophotometer. A reflectance of 4.72% from the etched surface in the wavelength range of 400–800 nm was obtained under etching time of 20 min, etching power of 150 W and F{sub SF6}/F{sub O2} of 18 sccm/6 sccm. Meanwhile, samples etched with F{sub O2} lower than 6 sccm can’t get low reflective silicon structure. Besides, the results show that overlong etching time of 30 min and too big etching power of 225 W would make the nanostructures too sparse to obtain a low reflectance.

  18. Dopamine D3 receptors inhibit hippocampal gamma oscillations by disturbing CA3 pyramidal cell firing synchrony

    Clément E. Lemercier

    2016-01-01

    Full Text Available Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer’s disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials during gamma oscillations and reduced the precision of the action potential phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects.

  19. Dopamine D3 Receptors Inhibit Hippocampal Gamma Oscillations by Disturbing CA3 Pyramidal Cell Firing Synchrony.

    Lemercier, Clément E; Schulz, Steffen B; Heidmann, Karin E; Kovács, Richard; Gerevich, Zoltan

    2015-01-01

    Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer's disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials (APs) during gamma oscillations and reduced the precision of the AP phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects. PMID:26779018

  20. Effects of lithium chloride on outward potassium currents in acutely isolated hippocampal CA1 pyramidal neurons

    ZHANG Chaofeng; DU Huizhi; YANG Pin

    2006-01-01

    Although lithium possesses neuroprotective functions, the molecular mechanism underlying its actions has not been fully elucidated. In the present paper, the effects of lithium chloride on voltage-dependent potassium currents in the CA1 pyramidal neurons acutely isolated from rat hippocampus were studied using the whole-cell patch-clamp technique. Depolarizing test pulses activated two components of outward potassium currents: a rapidly activating and inactivating component, IA and a delayed component, IK. Results showed that lithium chloride increased the amplitude of IA in a concentration-dependent manner. Half enhancement concentration (EC50) was 22.80±5.45 μmol·L-1. Lithium chloride of 25 μmol·L-1 shifted the steady-state activation curve and inactivation curve of IA to more negative potentials, but mainly affected the activation kinetics. The amplitude and the activation processes of IK were not affected by lithium chloride. The effects of lithium chloride on potassium channel appear to possess neuroprotective properties by Ca2+-lowing effects modulate neuronal excitability by activating IA in rat hippocampal neurons.

  1. Regulation of action potential waveforms by axonal GABAA receptors in cortical pyramidal neurons.

    Yang Xia

    Full Text Available GABAA receptors distributed in somatodendritic compartments play critical roles in regulating neuronal activities, including spike timing and firing pattern; however, the properties and functions of GABAA receptors at the axon are still poorly understood. By recording from the cut end (bleb of the main axon trunk of layer -5 pyramidal neurons in prefrontal cortical slices, we found that currents evoked by GABA iontophoresis could be blocked by picrotoxin, indicating the expression of GABAA receptors in axons. Stationary noise analysis revealed that single-channel properties of axonal GABAA receptors were similar to those of somatic receptors. Perforated patch recording with gramicidin revealed that the reversal potential of the GABA response was more negative than the resting membrane potential at the axon trunk, suggesting that GABA may hyperpolarize the axonal membrane potential. Further experiments demonstrated that the activation of axonal GABAA receptors regulated the amplitude and duration of action potentials (APs and decreased the AP-induced Ca2+ transients at the axon. Together, our results indicate that the waveform of axonal APs and the downstream Ca2+ signals are modulated by axonal GABAA receptors.

  2. Characterization of voltage-gated Ca(2+ conductances in layer 5 neocortical pyramidal neurons from rats.

    Mara Almog

    Full Text Available Neuronal voltage-gated Ca(2+ channels are involved in electrical signalling and in converting these signals into cytoplasmic calcium changes. One important function of voltage-gated Ca(2+ channels is generating regenerative dendritic Ca(2+ spikes. However, the Ca(2+ dependent mechanisms used to create these spikes are only partially understood. To start investigating this mechanism, we set out to kinetically and pharmacologically identify the sub-types of somatic voltage-gated Ca(2+ channels in pyramidal neurons from layer 5 of rat somatosensory cortex, using the nucleated configuration of the patch-clamp technique. The activation kinetics of the total Ba(2+ current revealed conductance activation only at medium and high voltages suggesting that T-type calcium channels were not present in the patches. Steady-state inactivation protocols in combination with pharmacology revealed the expression of R-type channels. Furthermore, pharmacological experiments identified 5 voltage-gated Ca(2+ channel sub-types - L-, N-, R- and P/Q-type. Finally, the activation of the Ca(2+ conductances was examined using physiologically derived voltage-clamp protocols including a calcium spike protocol and a mock back-propagating action potential (mBPAP protocol. These experiments enable us to suggest the possible contribution of the five Ca(2+ channel sub-types to Ca(2+ current flow during activation under physiological conditions.

  3. Pyramidal Lobe of the Thyroid Gland: Surgical Anatomy in Patients Undergoing Total Thyroidectomy

    Emin Gurleyik

    2015-01-01

    Full Text Available Background. Anatomic variations, the presence of the pyramidal lobe (PL, may impact completeness of thyroidectomy and effect of surgical treatment. Method. This study included 166 patients who underwent total thyroidectomy. The anterior cervical region between the thyroid isthmus and the hyoid bone was dissected during thyroid surgery. The incidence, size, and anatomical features of the PL were established in these patients. Results. The incidence of PL was 65.7%. No gender difference was found for PL incidence. The base of the PL was located at the isthmus in 52.3%, the left lobe in 29.4%, and the right lobe in 18.3% of patients. The mean length of the PL was 22.7 (range, 5–59 mm. The PL was longer than 30 mm in 23% of patients. One-third of the patients with short PL were men whereas women accounted for 80% of patients with long PL. Conclusions. The high incidence indicates that the PL is a common part of the thyroid. The PL generally originates from the isthmus near midline and is of variable length, extending from the isthmus up to the hyoid bone. Considering that the PL is a common structure, the prelaryngeal region should be dissected to achieve the completeness of thyroidectomy.

  4. Learning contextual relationships in mammograms using a hierarchical pyramid neural network.

    Sajda, Paul; Spence, Clay; Pearson, John

    2002-03-01

    This paper describes a pattern recognition architecture, which we term hierarchical pyramid/neural network (HPNN), that learns to exploit image structure at multiple resolutions for detecting clinically significant features in digital/digitized mammograms. The HPNN architecture consists of a hierarchy of neural networks, each network receiving feature inputs at a given scale as well as features constructed by networks lower in the hierarchy. Networks are trained using a novel error function for the supervised learning of image search/detection tasks when the position of the objects to be found is uncertain or ill defined. We have evaluated the HPNN's ability to eliminate false positive (FP) regions of interest generated by the University of Chicago's (UofC) Computer-aided diagnosis (CAD) systems for microcalcification and mass detection. Results show that the HPNN architecture, trained using the uncertain object position (UOP) error function, reduces the FP rate of a mammographic CAD system by approximately 50% without significant loss in sensitivity. Investigation into the types of FPs that the HPNN eliminates suggests that the pattern recognizer is automatically learning and exploiting contextual information. Clinical utility is demonstrated through the evaluation of an integrated system in a clinical reader study. We conclude that the HPNN architecture learns contextual relationships between features at multiple scales and integrates these features for detecting microcalcifications and breast masses. PMID:11989848

  5. THE KINETICS OF MULTIBRANCH INTEGRATION ON THE DENDRITIC ARBOR OF CA1 PYRAMIDAL NEURONS

    Sunggu eYang

    2014-05-01

    Full Text Available The process by which synaptic inputs separated in time and space are integrated by the dendritic arbor to produce a sequence of action potentials is among the most fundamental signal transformations that takes place within the central nervous system. Some aspects of this complex process, such as integration at the level of individual dendritic branches, have been extensively studied. But other aspects, such as how inputs from multiple branches are combined, and the kinetics of that integration have not been systematically examined. Using a 3D digital holographic photolysis technique to overcome the challenges posed by the complexities of the 3D anatomy of the dendritic arbor of CA1 pyramidal neurons for conventional photolysis, we show that integration on a single dendrite is fundamentally different from that on multiple dendrites. Multibranch integration occurring at oblique and basal dendrites allows somatic action potential firing of the cell to faithfully follow the driving stimuli over a significantly wider frequency range than what is possible with single branch integration. However, multibranch integration requires greater input strength to drive the somatic action potentials. This tradeoff between sensitivity and kinetics may explain the puzzling report of the predominance of multibranch, rather than single branch, integration from in vivo recordings during presentation of visual stimuli.

  6. Maternal mobile phone exposure alters intrinsic electrophysiological properties of CA1 pyramidal neurons in rat offspring.

    Razavinasab, Moazamehosadat; Moazzami, Kasra; Shabani, Mohammad

    2016-06-01

    Some studies have shown that exposure to electromagnetic field (EMF) may result in structural damage to neurons. In this study, we have elucidated the alteration in the hippocampal function of offspring Wistar rats (n = 8 rats in each group) that were chronically exposed to mobile phones during their gestational period by applying behavioral, histological, and electrophysiological tests. Rats in the EMF group were exposed to 900 MHz pulsed-EMF irradiation for 6 h/day. Whole cell recordings in hippocampal pyramidal cells in the mobile phone groups did show a decrease in neuronal excitability. Mobile phone exposure was mostly associated with a decrease in the number of action potentials fired in spontaneous activity and in response to current injection in both male and female groups. There was an increase in the amplitude of the afterhyperpolarization (AHP) in mobile phone rats compared with the control. The results of the passive avoidance and Morris water maze assessment of learning and memory performance showed that phone exposure significantly altered learning acquisition and memory retention in male and female rats compared with the control rats. Light microscopy study of brain sections of the control and mobile phone-exposed rats showed normal morphology.Our results suggest that exposure to mobile phones adversely affects the cognitive performance of both female and male offspring rats using behavioral and electrophysiological techniques. PMID:24604340

  7. Enhanced Sensitivity to Rapid Input Fluctuations by Nonlinear Threshold Dynamics in Neocortical Pyramidal Neurons.

    Mensi, Skander; Hagens, Olivier; Gerstner, Wulfram; Pozzorini, Christian

    2016-02-01

    The way in which single neurons transform input into output spike trains has fundamental consequences for network coding. Theories and modeling studies based on standard Integrate-and-Fire models implicitly assume that, in response to increasingly strong inputs, neurons modify their coding strategy by progressively reducing their selective sensitivity to rapid input fluctuations. Combining mathematical modeling with in vitro experiments, we demonstrate that, in L5 pyramidal neurons, the firing threshold dynamics adaptively adjust the effective timescale of somatic integration in order to preserve sensitivity to rapid signals over a broad range of input statistics. For that, a new Generalized Integrate-and-Fire model featuring nonlinear firing threshold dynamics and conductance-based adaptation is introduced that outperforms state-of-the-art neuron models in predicting the spiking activity of neurons responding to a variety of in vivo-like fluctuating currents. Our model allows for efficient parameter extraction and can be analytically mapped to a Generalized Linear Model in which both the input filter--describing somatic integration--and the spike-history filter--accounting for spike-frequency adaptation--dynamically adapt to the input statistics, as experimentally observed. Overall, our results provide new insights on the computational role of different biophysical processes known to underlie adaptive coding in single neurons and support previous theoretical findings indicating that the nonlinear dynamics of the firing threshold due to Na+-channel inactivation regulate the sensitivity to rapid input fluctuations. PMID:26907675

  8. Doing Business at the Base of the Pyramid: The Reality of Emerging Markets

    Reuben Abraham

    2012-06-01

    Full Text Available The role of business has traditionally been ignored in the global debates around economic development and poverty alleviation.  The recent global success of the mobile telephony industry, and the rapid growth in emerging markets over the last two decades has, however, forced a rethink. Instead of top-down, development aid-driven strategies, more discussions now focus on providing goods and services profitably to the base of the economic pyramid (BOP, like mobile phone companies have.Research teams at the Centre for Emerging Markets Solutions (CEMS have found that while it is possible to profitably serve BOP markets, it requires some departure from strategies advocated in the traditional BOP literature. In particular, it requires addressing issues around the macro-economic and business climate of the country; mispricing of risk; entrepreneurship; and a shift of focus away from multi-national corporations to the small business sector, and the transaction costs that bedevil it.This piece also examines a few commercially sustainable business models that have worked in these markets, and investigates a few sectors that commercial capital will find highly attractive and investable. Finally, we look at how to structure and commercialize the huge business opportunities that exist in addressing the inefficiencies of BOP markets, using a combination of business model innovation (especially around reduced cost structures, research, entrepreneurship, and patient capital.

  9. Beam pen lithography based on arrayed polydimethylsiloxane (PDMS) micro-pyramids spin-coated with carbon black photo-resist

    This paper presents a new method for preparing a polydimethylsiloxane (PDMS) mold which can be used in beam pen lithography for patterning a photo-resist (PR) layer in a maskless and direct-write manner. The PDMS mold contains an array of micro-pyramids on its surface and is spin-coated with a layer of carbon black PR which is an opaque material. Because of the arrayed pyramidal surface profile, the spin-coated carbon black PR layer is either thinner at the pyramid tips or does not cover the tips at all, which allows ultraviolet (UV) light to pass through the PDMS mold and forms an array of UV beams. The aperture size of the UV beams can be controlled at a sub-micrometer scale and hence can be used for micro/nano-patterning. Applying this carbon black-PR-coated PDMS mold in beam pen lithography along with a metal lift-off process, various metal dot patterns with a dot-size around 400 to 500 nm are successfully obtained. Both experimental results and theoretical analysis are given along with possible improvements and applications in the future. (paper)

  10. Material combinations and parametric study of thermal and mechanical performance of pyramidal core sandwich panels used for hypersonic aircrafts

    Zhang, Ruiping; Zhang, Xiaoqing; Lorenzini, Giulio; Xie, Gongnan

    2016-07-01

    A novel kind of lightweight integrated thermal protection system, named pyramidal core sandwich panel, is proposed to be a good safeguard for hypersonic aircrafts in the current study. Such system is considered as not only an insulation structure but also a load-bearing structure. In the context of design for hypersonic aircrafts, an efficient optimization should be paid enough attention. This paper concerns with the homogenization of the proposed pyramidal sandwich core panel using two-dimensional model in subsequent research for material selection. According to the required insulation performance and thermal-mechanical properties, several suitable material combinations are chosen as candidates for the pyramidal core sandwich panel by adopting finite element analysis and approximate response surface. To obtain lightweight structure with an excellent capability of heat insulation and load-bearing, an investigation on some specific design variables, which are significant for thermal-mechanical properties of the structure, is performed. Finally, a good balance between the insulation performance, the capability of load-bearing and the lightweight has attained.

  11. Effect of Pyramidal Training on Plasma Lipid Profile and Fibrinogen, and Blood Viscosity of Untrained Young Men

    Abbass Ghanbari-Niaki

    2013-09-01

    Full Text Available The present study examined the effects of progressive exercise (pyramidal short-term program on plasma fibrinogen, lipid profile and blood viscosity in untrained young men. Changes and imbalances in homeostasis lead to cause of heart attacks. There is conflicting information about the effect of exercise on these factors. 19 young healthy untrained men were randomly assigned to the exercise group (n = 10 and controls (n = 9 groups. Exercise training group with increasing severity of heart maximum 25 to 100 percent began to run the practice (pyramid in 42-minute sessions, 3 times a week, for 4 weeks. There was no significant difference between the parameters of body composition, control, and training groups. Levels of total cholesterol and low density lipoprotein density and viscosity of the blood significantly decreased in the training group compared with the control group (p value, respectively is 0.001, 0.001 and 0.035. The changes in the concentration of fibrinogen, high-density lipoprotein and triglycerides in both groups are not significant in both groups (p value, respectively is 0.645, 0.993 and 0.421. The present results show that it is possible that progressive training (pyramidal short-term program changed the levels of cardiovascular risk factors by reducing blood viscosity.

  12. A Simulation Study on the Effects of Dendritic Morphology on Layer V Prefontal Pyramidal Cell Firing Behavior

    Maria ePsarrou

    2014-09-01

    Full Text Available Pyramidal cells, the most abundant neurons in neocortex, exhibit significant structural variability across different brain areas and layers in different species. Moreover, in response to a somatic step current, these cells display a range of firing behaviors, the most common being (1 repetitive action potentials (Regular Spiking - RS, and (2 an initial cluster of 2-5 action potentials with short ISIs followed by single spikes (Intrinsic Bursting - IB. A correlation between firing behavior and dendritic morphology has recently been reported. In this work we use computational modeling to investigate quantitatively the effects of the basal dendritic tree morphology on the firing behavior of 112 three-dimensional reconstructions of layer V PFC rat pyramidal cells. Particularly, we focus on how different morphological (diameter, total length, volume and branch number and passive (Mean Electrotonic Path length features of basal dendritic trees shape somatic firing when the spatial distribution of ionic mechanisms in the basal dendritic trees is uniform or non-uniform. Our results suggest that total length, volume and branch number are the best morphological parameters to discriminate the cells as RS or IB, regardless of the distribution of ionic mechanisms in basal trees. The discriminatory power of total length, volume and branch number remains high in the presence of different apical dendrites. These results suggest that morphological variations in the basal dendritic trees of layer V pyramidal neurons in the PFC influence their firing patterns in a predictive manner and may in turn influence the information processing capabilities of these neurons.

  13. A Dietary Assessment of the U.S. Food Supply: Comparing Per Capita Food Consumption with Food Guide Pyramid Serving Recommendations

    Kantor, Linda Scott

    1998-01-01

    Most American diets do not meet Federal Food Guide Pyramid dietary recommendations. On average, people consume too many servings of added fats and sugars and too few servings of fruits, vegetables, dairy products, lean meats, and foods made from whole grains compared with a reference set of Food Guide Pyramid serving recommendations appropriate to the age and gender composition of the U.S. population. In addition, while the healthfulness of diets has improved over time, the pace of improvemen...

  14. Effect of nitric oxide synthase inhibition on long-term potentiation at associational-commissural and mossy fibre synapses on CA3 pyramidal neurones.

    Nicolarakis, P. J.; Lin, Y Q; Bennett, M. R.

    1994-01-01

    1. The sensitivity of long-term potentiation (LTP) to nitric oxide synthase (NOS) inhibition was determined for two synaptic input systems onto CA3 pyramidal neurones the LTP of which display differential sensitivity to N-methyl-D-aspartate (NMDA) receptor antagonists: the fimbrial input which activates the associational-commissural synapses on the distal apical dendrites and the mossy fibre input which synapses on the proximal apical dendrites of CA3 pyramidal neurones. 2. Following high-fre...

  15. TARGET-SPECIFIC OUTPUT PATTERNS CAN BE PREDICTED BY THE DISTRIBUTION OF REGULAR-SPIKING AND BURSTING PYRAMIDAL NEURONS IN THE SUBICULUM

    Kim, Yujin; Spruston, Nelson

    2011-01-01

    Pyramidal neurons in the subiculum project to a variety of cortical and subcortical areas in the brain to convey information processed in hippocampus. Previous studies have shown that two groups of subicular pyramidal neurons – regular-spiking and bursting neurons – are distributed in an organized fashion along the proximal-distal axis, with more regular-spiking neurons close to CA1 (proximal) and more bursting neurons close to presubiculum (distal). Anatomically, neurons projecting to some t...

  16. The influence of the opening between the heads of the two closest pyramids in textured surface for solar cells and its application on the spectral response

    Hamel, A.

    2014-05-01

    The work presented in this study is concerned the development of a new solar cell prototype in order to improve photovoltaic efficiency In this model we show that the material can have five and more successive incident ray absorptions instead of three currently, where we changed the direction of the reflected ray, by varying the angle between the two neighbouring pyramids, the incidence angle, the opening between the heads of the two closest pyramids and their height. Thus, with an angle between the two neighbouring pyramid varying between 24° and 12° and for angle of incidence varying between 78° and 84°. For these values of the angle between the two neighbouring pyramids and incidence angle, the opening between the heads of the two closest pyramids varied respectively from 4.25 to 2.10 μm for a pyramid height of 10 μm. This lead to a substantial increase of the spectral response and the photovoltaic efficiency.

  17. Layer 5 Pyramidal Neurons’ Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis

    Diana Urrego

    2015-01-01

    Full Text Available This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans.

  18. PRACTICAL ASPECTS OF MEDIATION

    IULIA FLOCA

    2011-01-01

    Today the Romanian state gives some advantages to those who use mediation. If the Romanian state would take further steps, mediation would work as in the countries with old tradition. The article refers to success and failure got in the two years of practice. The mediation can be seen in two aspects: The first aspect regarding the mediation itself can lead to a mediation agreement. The mediation agreement gives both winnings to the conflict parts and professional satisfactions to the mediator...

  19. Mu opioid receptor up-regulation and participation in excitability of hippocampal pyramidal cell electrophysiology

    Chronic administration of opiate antagonists to rats results in up-regulation of their brain opioid receptors. Using subcellular fractionation techniques, brain opioid receptors were resolved into two membrane populations, one associated with synaptic plasma membranes (SPM) and the other enriched in smooth endoplasmic reticulum and Golgi (microsomes). This study addressed in part the question of whether an antagonist induces up-regulation uniformly in these two populations. Rats were administered naltrexone by subcutaneously implanted osmotic minipumps. Forebrain mu receptor levels were determined by homologous displacement of (3H)D-ala2-mePhe4-gly-ol5-enkephalin (DAGO) followed by computer estimation of binding parameters. Receptor levels in crude membranes rose 77% after treatment. Microsomes displayed a 92% increase, a two-fold greater change than in SPMs (51%). These results establish that naltrexone induces up-regulation of both membrane populations; and that microsomal and SPM receptors represent discrete populations of intracellular and cell surface sites, respectively. Binding experiments on isolated hippocampi also demonstrated up-regulation (71%) of mu receptors. To demonstrate up-regulation of opioid receptors electrophysiologically, hippocampal slices were prepared from rats which had been chronically treated with naltrexone. After superfusion with DAGO, these slices showed a 42% greater population spike output than controls in response to the same EPSP input. Hippocampi from animals treated for two weeks showed an additional increase in sensitivity. The results support a disinhibitory role for opioids in pyramidal cell hyper-excitability. More importantly, they demonstrate a significant physiological correlate to opioid receptor up-regulation

  20. Tolerance of Pyramidal Tract to Gamma Knife Radiosurgery Based on Diffusion-Tensor Tractography

    Purpose: To minimize the morbidity of radiosurgery for critically located lesions, we integrated diffusion-tensor tractography into treatment planning for gamma-knife radiosurgery. We calculated the refined tolerance of the pyramidal tract (PT) after prospective application of the technique to additional patients. Methods and Materials: The relationship between the dosimetry during treatment planning and the development of subsequent motor complications was investigated in 24 patients, 9 studied retrospectively and 15 studied prospectively. The maximal dose to the PT and the volumes of the PT that received ≥20 Gy (20-Gy volume) and ≥25 Gy (25-Gy volume) were calculated. Univariate logistic regression analyses were used to produce dose-response curves. Differences in the tolerable dose according to the PT location were calculated. Results: Univariate logistic regression analysis of the motor complications revealed a significant independent correlation with the maximal dose to the PT and the 20- and 25-Gy volumes. The maximal dose to the PT with a 5% risk of motor complications was 23 Gy compared with 15 Gy in our previous report. The risk of motor complications was significantly greater in the internal capsule than in the corona radiata for the 20- and 25-Gy volumes in generalized Wilcoxon tests (p = 0.031), although no significant difference was observed for the maximal dose. Conclusion: The tolerable dose of the PT was greater than that previously reported. The internal capsule was more sensitive to high-dose irradiation over a wide area of the PT, probably owing to the dense concentration of motor fibers